// This file was generated by libdot/bin/concat.sh.
// It has been marked read-only for your safety.  Rather than
// edit it directly, please modify one of these source files.
//
// libdot/js/lib.js
// libdot/js/lib_polyfill.js
// libdot/js/lib_array.js
// libdot/js/lib_colors.js
// libdot/js/lib_f.js
// libdot/js/lib_i18n.js
// libdot/js/lib_message_manager.js
// libdot/js/lib_preference_manager.js
// libdot/js/lib_resource.js
// libdot/js/lib_storage.js
// libdot/js/lib_storage_chrome.js
// libdot/js/lib_storage_local.js
// libdot/js/lib_storage_memory.js
// libdot/js/lib_utf8.js
// libdot/third_party/wcwidth/lib_wc.js
// hterm/js/hterm.js
// hterm/js/hterm_accessibility_reader.js
// hterm/js/hterm_contextmenu.js
// hterm/js/hterm_frame.js
// hterm/js/hterm_keyboard.js
// hterm/js/hterm_keyboard_bindings.js
// hterm/js/hterm_keyboard_keymap.js
// hterm/js/hterm_keyboard_keypattern.js
// hterm/js/hterm_options.js
// hterm/js/hterm_parser.js
// hterm/js/hterm_parser_identifiers.js
// hterm/js/hterm_preference_manager.js
// hterm/js/hterm_pubsub.js
// hterm/js/hterm_screen.js
// hterm/js/hterm_scrollport.js
// hterm/js/hterm_terminal.js
// hterm/js/hterm_terminal_io.js
// hterm/js/hterm_text_attributes.js
// hterm/js/hterm_vt.js
// hterm/js/hterm_vt_character_map.js
// hterm/audio/bell.ogg
// hterm/images/icon-96.png
// libdot/js/lib_codec.js
// libdot/js/lib_credential_cache.js
// libdot/js/lib_event.js
// libdot/js/lib_fs.js
// libdot/third_party/punycode/lib_punycode.js

'use strict';

// SOURCE FILE: libdot/js/lib.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

if (typeof lib != 'undefined')
  throw new Error('Global "lib" object already exists.');

var lib = {};

/**
 * Map of "dependency" to ["source", ...].
 *
 * Each dependency is a object name, like "lib.fs", "source" is the url that
 * depends on the object.
 */
lib.runtimeDependencies_ = {};

/**
 * List of functions that need to be invoked during library initialization.
 *
 * Each element in the initCallbacks_ array is itself a two-element array.
 * Element 0 is a short string describing the owner of the init routine, useful
 * for debugging.  Element 1 is the callback function.
 */
lib.initCallbacks_ = [];

/**
 * Records a runtime dependency.
 *
 * This can be useful when you want to express a run-time dependency at
 * compile time.  It is not intended to be a full-fledged library system or
 * dependency tracker.  It's just there to make it possible to debug the
 * deps without running all the code.
 *
 * Object names are specified as strings.  For example...
 *
 *     lib.rtdep('lib.colors', 'lib.PreferenceManager');
 *
 * Object names need not be rooted by 'lib'.  You may use this to declare a
 * dependency on any object.
 *
 * The client program may call lib.ensureRuntimeDependencies() at startup in
 * order to ensure that all runtime dependencies have been met.
 *
 * @param {string} var_args One or more objects specified as strings.
 */
lib.rtdep = function(var_args) {
  var source;

  try {
    throw new Error();
  } catch (ex) {
    var stackArray = ex.stack.split('\n');
    // In Safari, the resulting stackArray will only have 2 elements and the
    // individual strings are formatted differently.
    if (stackArray.length >= 3) {
      source = stackArray[2].replace(/^\s*at\s+/, '');
    } else {
      source = stackArray[1].replace(/^\s*global code@/, '');
    }
  }

  for (var i = 0; i < arguments.length; i++) {
    var path = arguments[i];
    if (path instanceof Array) {
      lib.rtdep.apply(lib, path);
    } else {
      var ary = this.runtimeDependencies_[path];
      if (!ary)
        ary = this.runtimeDependencies_[path] = [];
      ary.push(source);
    }
  }
};

/**
 * Ensures that all runtime dependencies are met, or an exception is thrown.
 *
 * Every unmet runtime dependency will be logged to the JS console.  If at
 * least one dependency is unmet this will raise an exception.
 */
lib.ensureRuntimeDependencies_ = function() {
  var passed = true;

  for (var path in lib.runtimeDependencies_) {
    var sourceList = lib.runtimeDependencies_[path];
    var names = path.split('.');

    // In a document context 'window' is the global object.  In a worker it's
    // called 'self'.
    var obj = (window || self);
    for (var i = 0; i < names.length; i++) {
      if (!(names[i] in obj)) {
        console.warn('Missing "' + path + '" is needed by', sourceList);
        passed = false;
        break;
      }

      obj = obj[names[i]];
    }
  }

  if (!passed)
    throw new Error('Failed runtime dependency check');
};

/**
 * Register an initialization function.
 *
 * The initialization functions are invoked in registration order when
 * lib.init() is invoked.  Each function will receive a single parameter, which
 * is a function to be invoked when it completes its part of the initialization.
 *
 * @param {string} name A short descriptive name of the init routine useful for
 *     debugging.
 * @param {function(function)} callback The initialization function to register.
 * @return {function} The callback parameter.
 */
lib.registerInit = function(name, callback) {
  lib.initCallbacks_.push([name, callback]);
  return callback;
};

/**
 * Initialize the library.
 *
 * This will ensure that all registered runtime dependencies are met, and
 * invoke any registered initialization functions.
 *
 * Initialization is asynchronous.  The library is not ready for use until
 * the onInit function is invoked.
 *
 * @param {function()} onInit The function to invoke when initialization is
 *     complete.
 * @param {function(*)} opt_logFunction An optional function to send
 *     initialization related log messages to.
 */
lib.init = function(onInit, opt_logFunction) {
  var ary = lib.initCallbacks_;

  var initNext = function() {
    if (ary.length) {
      var rec = ary.shift();
      if (opt_logFunction)
        opt_logFunction('init: ' + rec[0]);
      rec[1](lib.f.alarm(initNext));
    } else {
      onInit();
    }
  };

  if (typeof onInit != 'function')
    throw new Error('Missing or invalid argument: onInit');

  lib.ensureRuntimeDependencies_();

  setTimeout(initNext, 0);
};
// SOURCE FILE: libdot/js/lib_polyfill.js
// Copyright 2017 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

/**
 * @fileoverview Polyfills for ES2016+ features we want to use.
 */

// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/padStart
if (!String.prototype.padStart) {
  String.prototype.padStart = function(targetLength, padString) {
    // If the string is already long enough, nothing to do!
    targetLength -= this.length;
    if (targetLength <= 0)
      return String(this);

    if (padString === undefined)
      padString = ' ';

    // In case the pad is multiple chars long.
    if (targetLength > padString.length)
      padString = padString.repeat((targetLength / padString.length) + 1);

    return padString.slice(0, targetLength) + String(this);
  };
}

// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/padEnd
if (!String.prototype.padEnd) {
  String.prototype.padEnd = function(targetLength, padString) {
    // If the string is already long enough, nothing to do!
    targetLength -= this.length;
    if (targetLength <= 0)
      return String(this);

    if (padString === undefined)
      padString = ' ';

    // In case the pad is multiple chars long.
    if (targetLength > padString.length)
      padString = padString.repeat((targetLength / padString.length) + 1);

    return String(this) + padString.slice(0, targetLength);
  };
}

// https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_objects/Object/values
// https://github.com/tc39/proposal-object-values-entries/blob/master/polyfill.js
if (!Object.values || !Object.entries) {
  const reduce = Function.bind.call(Function.call, Array.prototype.reduce);
  const isEnumerable = Function.bind.call(Function.call,
      Object.prototype.propertyIsEnumerable);
  const concat = Function.bind.call(Function.call, Array.prototype.concat);

  if (!Object.values) {
    Object.values = function values(O) {
      return reduce(Reflect.ownKeys(O), (v, k) => concat(v,
          typeof k === 'string' && isEnumerable(O, k) ? [O[k]] : []), []);
    };
  }

  if (!Object.entries) {
    Object.entries = function entries(O) {
      return reduce(Reflect.ownKeys(O), (e, k) => concat(e,
          typeof k === 'string' && isEnumerable(O, k) ? [[k, O[k]]] : []), []);
    };
  }
}

// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/finally
// https://github.com/tc39/proposal-promise-finally/blob/master/polyfill.js
if (typeof Promise.prototype.finally !== 'function') {
  const speciesConstructor = function(O, defaultConstructor) {
    if (!O || (typeof O !== 'object' && typeof O !== 'function')) {
      throw new TypeError('Assertion failed: Type(O) is not Object');
    }
    const C = O.constructor;
    if (typeof C === 'undefined') {
      return defaultConstructor;
    }
    if (!C || (typeof C !== 'object' && typeof C !== 'function')) {
      throw new TypeError('O.constructor is not an Object');
    }
    const S =
        typeof Symbol === 'function' && typeof Symbol.species === 'symbol' ?
        C[Symbol.species] : undefined;
    if (S == null) {
      return defaultConstructor;
    }
    if (typeof S === 'function' && S.prototype) {
      return S;
    }
    throw new TypeError('no constructor found');
  };

  const shim = {
    finally(onFinally) {
      const promise = this;
      if (typeof promise !== 'object' || promise === null) {
        throw new TypeError('"this" value is not an Object');
      }
      const C = speciesConstructor(promise, Promise);
      if (typeof onFinally !== 'function') {
        return Promise.prototype.then.call(promise, onFinally, onFinally);
      }
      return Promise.prototype.then.call(
        promise,
        x => new C(resolve => resolve(onFinally())).then(() => x),
        e => new C(resolve => resolve(onFinally())).then(() => { throw e; })
      );
    }
  };
  Object.defineProperty(Promise.prototype, 'finally', {
    configurable: true, writable: true, value: shim.finally,
  });
}
// SOURCE FILE: libdot/js/lib_array.js
// Copyright 2017 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

/**
 * @fileoverview Helper functions for (typed) arrays.
 */

lib.array = {};

/**
 * Convert an array of four unsigned bytes into an unsigned 32-bit integer (big
 * endian).
 *
 * @param {!Array.<!number>} array
 * @returns {!number}
 */
lib.array.arrayBigEndianToUint32 = function(array) {
  const maybeSigned =
      (array[0] << 24) | (array[1] << 16) | (array[2] << 8) | (array[3] << 0);
  // Interpret the result of the bit operations as an unsigned integer.
  return maybeSigned >>> 0;
};

/**
 * Convert an unsigned 32-bit integer into an array of four unsigned bytes (big
 * endian).
 *
 * @param {!number} uint32
 * @returns {!Array.<!number>}
 */
lib.array.uint32ToArrayBigEndian = function(uint32) {
  return [
    (uint32 >>> 24) & 0xFF,
    (uint32 >>> 16) & 0xFF,
    (uint32 >>> 8) & 0xFF,
    (uint32 >>> 0) & 0xFF,
  ];
};

/**
 * Concatenate an arbitrary number of typed arrays of the same type into a new
 * typed array of this type.
 *
 * @template TYPED_ARRAY
 * @param {...!TYPED_ARRAY} arrays
 * @returns {!TYPED_ARRAY}
 */
lib.array.concatTyped = function(...arrays) {
  let resultLength = 0;
  for (const array of arrays) {
    resultLength += array.length;
  }
  const result = new arrays[0].constructor(resultLength);
  let pos = 0;
  for (const array of arrays) {
    result.set(array, pos);
    pos += array.length;
  }
  return result;
};

/**
 * Compare two array-like objects entrywise.
 *
 * @template ARRAY_LIKE
 * @param {?ARRAY_LIKE} a
 * @param {?ARRAY_LIKE} b
 * @returns {!boolean} true if both arrays are null or they agree entrywise;
 *     false otherwise.
 */
lib.array.compare = function(a, b) {
  if (a === null || b === null) {
    return a === null && b === null;
  }

  if (a.length !== b.length) {
    return false;
  }

  for (let i = 0; i < a.length; i++) {
    if (a[i] !== b[i]) {
      return false;
    }
  }
  return true;
};
// SOURCE FILE: libdot/js/lib_colors.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

/**
 * Namespace for color utilities.
 */
lib.colors = {};

/**
 * First, some canned regular expressions we're going to use in this file.
 *
 *
 *                              BRACE YOURSELF
 *
 *                                 ,~~~~.
 *                                 |>_< ~~
 *                                3`---'-/.
 *                                3:::::\v\
 *                               =o=:::::\,\
 *                                | :::::\,,\
 *
 *                        THE REGULAR EXPRESSIONS
 *                               ARE COMING.
 *
 * There's no way to break long RE literals in JavaScript.  Fix that why don't
 * you?  Oh, and also there's no way to write a string that doesn't interpret
 * escapes.
 *
 * Instead, we stoop to this .replace() trick.
 */
lib.colors.re_ = {
  // CSS hex color, #RGB.
  hex16: /#([a-f0-9])([a-f0-9])([a-f0-9])/i,

  // CSS hex color, #RRGGBB.
  hex24: /#([a-f0-9]{2})([a-f0-9]{2})([a-f0-9]{2})/i,

  // CSS rgb color, rgb(rrr,ggg,bbb).
  rgb: new RegExp(
      ('^/s*rgb/s*/(/s*(/d{1,3})/s*,/s*(/d{1,3})/s*,' +
       '/s*(/d{1,3})/s*/)/s*$'
       ).replace(/\//g, '\\'), 'i'),

  // CSS rgb color, rgb(rrr,ggg,bbb,aaa).
  rgba: new RegExp(
      ('^/s*rgba/s*' +
       '/(/s*(/d{1,3})/s*,/s*(/d{1,3})/s*,/s*(/d{1,3})/s*' +
       '(?:,/s*(/d+(?:/./d+)?)/s*)/)/s*$'
       ).replace(/\//g, '\\'), 'i'),

  // Either RGB or RGBA.
  rgbx: new RegExp(
      ('^/s*rgba?/s*' +
       '/(/s*(/d{1,3})/s*,/s*(/d{1,3})/s*,/s*(/d{1,3})/s*' +
       '(?:,/s*(/d+(?:/./d+)?)/s*)?/)/s*$'
       ).replace(/\//g, '\\'), 'i'),

  // An X11 "rgb:dddd/dddd/dddd" value.
  x11rgb: /^\s*rgb:([a-f0-9]{1,4})\/([a-f0-9]{1,4})\/([a-f0-9]{1,4})\s*$/i,

  // English color name.
  name: /[a-z][a-z0-9\s]+/,
};

/**
 * Convert a CSS rgb(ddd,ddd,ddd) color value into an X11 color value.
 *
 * Other CSS color values are ignored to ensure sanitary data handling.
 *
 * Each 'ddd' component is a one byte value specified in decimal.
 *
 * @param {string} value The CSS color value to convert.
 * @return {string} The X11 color value or null if the value could not be
 *     converted.
 */
lib.colors.rgbToX11 = function(value) {
  function scale(v) {
    v = (Math.min(v, 255) * 257).toString(16);
    return lib.f.zpad(v, 4);
  }

  var ary = value.match(lib.colors.re_.rgbx);
  if (!ary)
    return null;

  return 'rgb:' + scale(ary[1]) + '/' + scale(ary[2]) + '/' + scale(ary[3]);
};

/**
 * Convert a legacy X11 colover value into an CSS rgb(...) color value.
 *
 * They take the form:
 * 12 bit: #RGB          -> #R000G000B000
 * 24 bit: #RRGGBB       -> #RR00GG00BB00
 * 36 bit: #RRRGGGBBB    -> #RRR0GGG0BBB0
 * 48 bit: #RRRRGGGGBBBB
 * These are the most significant bits.
 *
 * Truncate values back down to 24 bit since that's all CSS supports.
 */
lib.colors.x11HexToCSS = function(v) {
  if (!v.startsWith('#'))
    return null;
  // Strip the leading # off.
  v = v.substr(1);

  // Reject unknown sizes.
  if ([3, 6, 9, 12].indexOf(v.length) == -1)
    return null;

  // Reject non-hex values.
  if (v.match(/[^a-f0-9]/i))
    return null;

  // Split the colors out.
  var size = v.length / 3;
  var r = v.substr(0, size);
  var g = v.substr(size, size);
  var b = v.substr(size + size, size);

  // Normalize to 16 bits.
  function norm16(v) {
    v = parseInt(v, 16);
    return size == 2 ? v :         // 16 bit
           size == 1 ? v << 4 :    // 8 bit
           v >> (4 * (size - 2));  // 24 or 32 bit
  }
  return lib.colors.arrayToRGBA([r, g, b].map(norm16));
};

/**
 * Convert an X11 color value into an CSS rgb(...) color value.
 *
 * The X11 value may be an X11 color name, or an RGB value of the form
 * rgb:hhhh/hhhh/hhhh.  If a component value is less than 4 digits it is
 * padded out to 4, then scaled down to fit in a single byte.
 *
 * @param {string} value The X11 color value to convert.
 * @return {string} The CSS color value or null if the value could not be
 *     converted.
 */
lib.colors.x11ToCSS = function(v) {
  function scale(v) {
    // Pad out values with less than four digits.  This padding (probably)
    // matches xterm.  It's difficult to say for sure since xterm seems to
    // arrive at a padded value and then perform some combination of
    // gamma correction, color space transformation, and quantization.

    if (v.length == 1) {
      // Single digits pad out to four by repeating the character.  "f" becomes
      // "ffff".  Scaling down a hex value of this pattern by 257 is the same
      // as cutting off one byte.  We skip the middle step and just double
      // the character.
      return parseInt(v + v, 16);
    }

    if (v.length == 2) {
      // Similar deal here.  X11 pads two digit values by repeating the
      // byte (or scale up by 257).  Since we're going to scale it back
      // down anyway, we can just return the original value.
      return parseInt(v, 16);
    }

    if (v.length == 3) {
      // Three digit values seem to be padded by repeating the final digit.
      // e.g. 10f becomes 10ff.
      v = v + v.substr(2);
    }

    // Scale down the 2 byte value.
    return Math.round(parseInt(v, 16) / 257);
  }

  var ary = v.match(lib.colors.re_.x11rgb);
  if (!ary) {
    // Handle the legacy format.
    if (v.startsWith('#'))
      return lib.colors.x11HexToCSS(v);
    else
      return lib.colors.nameToRGB(v);
  }

  ary.splice(0, 1);
  return lib.colors.arrayToRGBA(ary.map(scale));
};

/**
 * Converts one or more CSS '#RRGGBB' color values into their rgb(...)
 * form.
 *
 * Arrays are converted in place. If a value cannot be converted, it is
 * replaced with null.
 *
 * @param {string|Array.<string>} A single RGB value or array of RGB values to
 *     convert.
 * @return {string|Array.<string>} The converted value or values.
 */
lib.colors.hexToRGB = function(arg) {
  var hex16 = lib.colors.re_.hex16;
  var hex24 = lib.colors.re_.hex24;

  function convert(hex) {
    if (hex.length == 4) {
      hex = hex.replace(hex16, function(h, r, g, b) {
        return "#" + r + r + g + g + b + b;
      });
    }
    var ary = hex.match(hex24);
    if (!ary)
      return null;

    return 'rgb(' + parseInt(ary[1], 16) + ', ' +
        parseInt(ary[2], 16) + ', ' +
        parseInt(ary[3], 16) + ')';
  }

  if (arg instanceof Array) {
    for (var i = 0; i < arg.length; i++) {
      arg[i] = convert(arg[i]);
    }
  } else {
    arg = convert(arg);
  }

  return arg;
};

/**
 * Converts one or more CSS rgb(...) forms into their '#RRGGBB' color values.
 *
 * If given an rgba(...) form, the alpha field is thrown away.
 *
 * Arrays are converted in place. If a value cannot be converted, it is
 * replaced with null.
 *
 * @param {string|Array.<string>} A single rgb(...) value or array of rgb(...)
 *     values to convert.
 * @return {string|Array.<string>} The converted value or values.
 */
lib.colors.rgbToHex = function(arg) {
  function convert(rgb) {
    var ary = lib.colors.crackRGB(rgb);
    if (!ary)
      return null;
    return '#' + lib.f.zpad(((parseInt(ary[0]) << 16) |
                             (parseInt(ary[1]) <<  8) |
                             (parseInt(ary[2]) <<  0)).toString(16), 6);
  }

  if (arg instanceof Array) {
    for (var i = 0; i < arg.length; i++) {
      arg[i] = convert(arg[i]);
    }
  } else {
    arg = convert(arg);
  }

  return arg;
};

/**
 * Take any valid css color definition and turn it into an rgb or rgba value.
 *
 * Returns null if the value could not be normalized.
 */
lib.colors.normalizeCSS = function(def) {
  if (def.startsWith('#'))
    return lib.colors.hexToRGB(def);

  if (lib.colors.re_.rgbx.test(def))
    return def;

  return lib.colors.nameToRGB(def);
};

/**
 * Convert a 3 or 4 element array into an rgba(...) string.
 */
lib.colors.arrayToRGBA = function(ary) {
  var alpha = (ary.length > 3) ? ary[3] : 1;
  return 'rgba(' + ary[0] + ', ' + ary[1] + ', ' + ary[2] + ', ' + alpha + ')';
};

/**
 * Overwrite the alpha channel of an rgb/rgba color.
 */
lib.colors.setAlpha = function(rgb, alpha) {
  var ary = lib.colors.crackRGB(rgb);
  ary[3] = alpha;
  return lib.colors.arrayToRGBA(ary);
};

/**
 * Mix a percentage of a tint color into a base color.
 */
lib.colors.mix = function(base, tint, percent) {
  var ary1 = lib.colors.crackRGB(base);
  var ary2 = lib.colors.crackRGB(tint);

  for (var i = 0; i < 4; ++i) {
    var diff = ary2[i] - ary1[i];
    ary1[i] = Math.round(parseInt(ary1[i]) + diff * percent);
  }

  return lib.colors.arrayToRGBA(ary1);
};

/**
 * Split an rgb/rgba color into an array of its components.
 *
 * On success, a 4 element array will be returned.  For rgb values, the alpha
 * will be set to 1.
 */
lib.colors.crackRGB = function(color) {
  if (color.startsWith('rgba')) {
    var ary = color.match(lib.colors.re_.rgba);
    if (ary) {
      ary.shift();
      return ary;
    }
  } else {
    var ary = color.match(lib.colors.re_.rgb);
    if (ary) {
      ary.shift();
      ary.push('1');
      return ary;
    }
  }

  console.error('Couldn\'t crack: ' + color);
  return null;
};

/**
 * Convert an X11 color name into a CSS rgb(...) value.
 *
 * Names are stripped of spaces and converted to lowercase.  If the name is
 * unknown, null is returned.
 *
 * This list of color name to RGB mapping is derived from the stock X11
 * rgb.txt file.
 *
 * @param {string} name The color name to convert.
 * @return {string} The corresponding CSS rgb(...) value.
 */
lib.colors.nameToRGB = function(name) {
  if (name in lib.colors.colorNames)
    return lib.colors.colorNames[name];

  name = name.toLowerCase();
  if (name in lib.colors.colorNames)
    return lib.colors.colorNames[name];

  name = name.replace(/\s+/g, '');
  if (name in lib.colors.colorNames)
    return lib.colors.colorNames[name];

  return null;
};

/**
 * The stock color palette.
 */
lib.colors.stockColorPalette = lib.colors.hexToRGB
  ([// The "ANSI 16"...
    '#000000', '#CC0000', '#4E9A06', '#C4A000',
    '#3465A4', '#75507B', '#06989A', '#D3D7CF',
    '#555753', '#EF2929', '#00BA13', '#FCE94F',
    '#729FCF', '#F200CB', '#00B5BD', '#EEEEEC',

    // The 6x6 color cubes...
    '#000000', '#00005F', '#000087', '#0000AF', '#0000D7', '#0000FF',
    '#005F00', '#005F5F', '#005F87', '#005FAF', '#005FD7', '#005FFF',
    '#008700', '#00875F', '#008787', '#0087AF', '#0087D7', '#0087FF',
    '#00AF00', '#00AF5F', '#00AF87', '#00AFAF', '#00AFD7', '#00AFFF',
    '#00D700', '#00D75F', '#00D787', '#00D7AF', '#00D7D7', '#00D7FF',
    '#00FF00', '#00FF5F', '#00FF87', '#00FFAF', '#00FFD7', '#00FFFF',

    '#5F0000', '#5F005F', '#5F0087', '#5F00AF', '#5F00D7', '#5F00FF',
    '#5F5F00', '#5F5F5F', '#5F5F87', '#5F5FAF', '#5F5FD7', '#5F5FFF',
    '#5F8700', '#5F875F', '#5F8787', '#5F87AF', '#5F87D7', '#5F87FF',
    '#5FAF00', '#5FAF5F', '#5FAF87', '#5FAFAF', '#5FAFD7', '#5FAFFF',
    '#5FD700', '#5FD75F', '#5FD787', '#5FD7AF', '#5FD7D7', '#5FD7FF',
    '#5FFF00', '#5FFF5F', '#5FFF87', '#5FFFAF', '#5FFFD7', '#5FFFFF',

    '#870000', '#87005F', '#870087', '#8700AF', '#8700D7', '#8700FF',
    '#875F00', '#875F5F', '#875F87', '#875FAF', '#875FD7', '#875FFF',
    '#878700', '#87875F', '#878787', '#8787AF', '#8787D7', '#8787FF',
    '#87AF00', '#87AF5F', '#87AF87', '#87AFAF', '#87AFD7', '#87AFFF',
    '#87D700', '#87D75F', '#87D787', '#87D7AF', '#87D7D7', '#87D7FF',
    '#87FF00', '#87FF5F', '#87FF87', '#87FFAF', '#87FFD7', '#87FFFF',

    '#AF0000', '#AF005F', '#AF0087', '#AF00AF', '#AF00D7', '#AF00FF',
    '#AF5F00', '#AF5F5F', '#AF5F87', '#AF5FAF', '#AF5FD7', '#AF5FFF',
    '#AF8700', '#AF875F', '#AF8787', '#AF87AF', '#AF87D7', '#AF87FF',
    '#AFAF00', '#AFAF5F', '#AFAF87', '#AFAFAF', '#AFAFD7', '#AFAFFF',
    '#AFD700', '#AFD75F', '#AFD787', '#AFD7AF', '#AFD7D7', '#AFD7FF',
    '#AFFF00', '#AFFF5F', '#AFFF87', '#AFFFAF', '#AFFFD7', '#AFFFFF',

    '#D70000', '#D7005F', '#D70087', '#D700AF', '#D700D7', '#D700FF',
    '#D75F00', '#D75F5F', '#D75F87', '#D75FAF', '#D75FD7', '#D75FFF',
    '#D78700', '#D7875F', '#D78787', '#D787AF', '#D787D7', '#D787FF',
    '#D7AF00', '#D7AF5F', '#D7AF87', '#D7AFAF', '#D7AFD7', '#D7AFFF',
    '#D7D700', '#D7D75F', '#D7D787', '#D7D7AF', '#D7D7D7', '#D7D7FF',
    '#D7FF00', '#D7FF5F', '#D7FF87', '#D7FFAF', '#D7FFD7', '#D7FFFF',

    '#FF0000', '#FF005F', '#FF0087', '#FF00AF', '#FF00D7', '#FF00FF',
    '#FF5F00', '#FF5F5F', '#FF5F87', '#FF5FAF', '#FF5FD7', '#FF5FFF',
    '#FF8700', '#FF875F', '#FF8787', '#FF87AF', '#FF87D7', '#FF87FF',
    '#FFAF00', '#FFAF5F', '#FFAF87', '#FFAFAF', '#FFAFD7', '#FFAFFF',
    '#FFD700', '#FFD75F', '#FFD787', '#FFD7AF', '#FFD7D7', '#FFD7FF',
    '#FFFF00', '#FFFF5F', '#FFFF87', '#FFFFAF', '#FFFFD7', '#FFFFFF',

    // The greyscale ramp...
    '#080808', '#121212', '#1C1C1C', '#262626', '#303030', '#3A3A3A',
    '#444444', '#4E4E4E', '#585858', '#626262', '#6C6C6C', '#767676',
    '#808080', '#8A8A8A', '#949494', '#9E9E9E', '#A8A8A8', '#B2B2B2',
    '#BCBCBC', '#C6C6C6', '#D0D0D0', '#DADADA', '#E4E4E4', '#EEEEEE'
   ]);

/**
 * The current color palette, possibly with user changes.
 */
lib.colors.colorPalette = lib.colors.stockColorPalette;

/**
 * Named colors according to the stock X11 rgb.txt file.
 */
lib.colors.colorNames = {
  "aliceblue": "rgb(240, 248, 255)",
  "antiquewhite": "rgb(250, 235, 215)",
  "antiquewhite1": "rgb(255, 239, 219)",
  "antiquewhite2": "rgb(238, 223, 204)",
  "antiquewhite3": "rgb(205, 192, 176)",
  "antiquewhite4": "rgb(139, 131, 120)",
  "aquamarine": "rgb(127, 255, 212)",
  "aquamarine1": "rgb(127, 255, 212)",
  "aquamarine2": "rgb(118, 238, 198)",
  "aquamarine3": "rgb(102, 205, 170)",
  "aquamarine4": "rgb(69, 139, 116)",
  "azure": "rgb(240, 255, 255)",
  "azure1": "rgb(240, 255, 255)",
  "azure2": "rgb(224, 238, 238)",
  "azure3": "rgb(193, 205, 205)",
  "azure4": "rgb(131, 139, 139)",
  "beige": "rgb(245, 245, 220)",
  "bisque": "rgb(255, 228, 196)",
  "bisque1": "rgb(255, 228, 196)",
  "bisque2": "rgb(238, 213, 183)",
  "bisque3": "rgb(205, 183, 158)",
  "bisque4": "rgb(139, 125, 107)",
  "black": "rgb(0, 0, 0)",
  "blanchedalmond": "rgb(255, 235, 205)",
  "blue": "rgb(0, 0, 255)",
  "blue1": "rgb(0, 0, 255)",
  "blue2": "rgb(0, 0, 238)",
  "blue3": "rgb(0, 0, 205)",
  "blue4": "rgb(0, 0, 139)",
  "blueviolet": "rgb(138, 43, 226)",
  "brown": "rgb(165, 42, 42)",
  "brown1": "rgb(255, 64, 64)",
  "brown2": "rgb(238, 59, 59)",
  "brown3": "rgb(205, 51, 51)",
  "brown4": "rgb(139, 35, 35)",
  "burlywood": "rgb(222, 184, 135)",
  "burlywood1": "rgb(255, 211, 155)",
  "burlywood2": "rgb(238, 197, 145)",
  "burlywood3": "rgb(205, 170, 125)",
  "burlywood4": "rgb(139, 115, 85)",
  "cadetblue": "rgb(95, 158, 160)",
  "cadetblue1": "rgb(152, 245, 255)",
  "cadetblue2": "rgb(142, 229, 238)",
  "cadetblue3": "rgb(122, 197, 205)",
  "cadetblue4": "rgb(83, 134, 139)",
  "chartreuse": "rgb(127, 255, 0)",
  "chartreuse1": "rgb(127, 255, 0)",
  "chartreuse2": "rgb(118, 238, 0)",
  "chartreuse3": "rgb(102, 205, 0)",
  "chartreuse4": "rgb(69, 139, 0)",
  "chocolate": "rgb(210, 105, 30)",
  "chocolate1": "rgb(255, 127, 36)",
  "chocolate2": "rgb(238, 118, 33)",
  "chocolate3": "rgb(205, 102, 29)",
  "chocolate4": "rgb(139, 69, 19)",
  "coral": "rgb(255, 127, 80)",
  "coral1": "rgb(255, 114, 86)",
  "coral2": "rgb(238, 106, 80)",
  "coral3": "rgb(205, 91, 69)",
  "coral4": "rgb(139, 62, 47)",
  "cornflowerblue": "rgb(100, 149, 237)",
  "cornsilk": "rgb(255, 248, 220)",
  "cornsilk1": "rgb(255, 248, 220)",
  "cornsilk2": "rgb(238, 232, 205)",
  "cornsilk3": "rgb(205, 200, 177)",
  "cornsilk4": "rgb(139, 136, 120)",
  "cyan": "rgb(0, 255, 255)",
  "cyan1": "rgb(0, 255, 255)",
  "cyan2": "rgb(0, 238, 238)",
  "cyan3": "rgb(0, 205, 205)",
  "cyan4": "rgb(0, 139, 139)",
  "darkblue": "rgb(0, 0, 139)",
  "darkcyan": "rgb(0, 139, 139)",
  "darkgoldenrod": "rgb(184, 134, 11)",
  "darkgoldenrod1": "rgb(255, 185, 15)",
  "darkgoldenrod2": "rgb(238, 173, 14)",
  "darkgoldenrod3": "rgb(205, 149, 12)",
  "darkgoldenrod4": "rgb(139, 101, 8)",
  "darkgray": "rgb(169, 169, 169)",
  "darkgreen": "rgb(0, 100, 0)",
  "darkgrey": "rgb(169, 169, 169)",
  "darkkhaki": "rgb(189, 183, 107)",
  "darkmagenta": "rgb(139, 0, 139)",
  "darkolivegreen": "rgb(85, 107, 47)",
  "darkolivegreen1": "rgb(202, 255, 112)",
  "darkolivegreen2": "rgb(188, 238, 104)",
  "darkolivegreen3": "rgb(162, 205, 90)",
  "darkolivegreen4": "rgb(110, 139, 61)",
  "darkorange": "rgb(255, 140, 0)",
  "darkorange1": "rgb(255, 127, 0)",
  "darkorange2": "rgb(238, 118, 0)",
  "darkorange3": "rgb(205, 102, 0)",
  "darkorange4": "rgb(139, 69, 0)",
  "darkorchid": "rgb(153, 50, 204)",
  "darkorchid1": "rgb(191, 62, 255)",
  "darkorchid2": "rgb(178, 58, 238)",
  "darkorchid3": "rgb(154, 50, 205)",
  "darkorchid4": "rgb(104, 34, 139)",
  "darkred": "rgb(139, 0, 0)",
  "darksalmon": "rgb(233, 150, 122)",
  "darkseagreen": "rgb(143, 188, 143)",
  "darkseagreen1": "rgb(193, 255, 193)",
  "darkseagreen2": "rgb(180, 238, 180)",
  "darkseagreen3": "rgb(155, 205, 155)",
  "darkseagreen4": "rgb(105, 139, 105)",
  "darkslateblue": "rgb(72, 61, 139)",
  "darkslategray": "rgb(47, 79, 79)",
  "darkslategray1": "rgb(151, 255, 255)",
  "darkslategray2": "rgb(141, 238, 238)",
  "darkslategray3": "rgb(121, 205, 205)",
  "darkslategray4": "rgb(82, 139, 139)",
  "darkslategrey": "rgb(47, 79, 79)",
  "darkturquoise": "rgb(0, 206, 209)",
  "darkviolet": "rgb(148, 0, 211)",
  "debianred": "rgb(215, 7, 81)",
  "deeppink": "rgb(255, 20, 147)",
  "deeppink1": "rgb(255, 20, 147)",
  "deeppink2": "rgb(238, 18, 137)",
  "deeppink3": "rgb(205, 16, 118)",
  "deeppink4": "rgb(139, 10, 80)",
  "deepskyblue": "rgb(0, 191, 255)",
  "deepskyblue1": "rgb(0, 191, 255)",
  "deepskyblue2": "rgb(0, 178, 238)",
  "deepskyblue3": "rgb(0, 154, 205)",
  "deepskyblue4": "rgb(0, 104, 139)",
  "dimgray": "rgb(105, 105, 105)",
  "dimgrey": "rgb(105, 105, 105)",
  "dodgerblue": "rgb(30, 144, 255)",
  "dodgerblue1": "rgb(30, 144, 255)",
  "dodgerblue2": "rgb(28, 134, 238)",
  "dodgerblue3": "rgb(24, 116, 205)",
  "dodgerblue4": "rgb(16, 78, 139)",
  "firebrick": "rgb(178, 34, 34)",
  "firebrick1": "rgb(255, 48, 48)",
  "firebrick2": "rgb(238, 44, 44)",
  "firebrick3": "rgb(205, 38, 38)",
  "firebrick4": "rgb(139, 26, 26)",
  "floralwhite": "rgb(255, 250, 240)",
  "forestgreen": "rgb(34, 139, 34)",
  "gainsboro": "rgb(220, 220, 220)",
  "ghostwhite": "rgb(248, 248, 255)",
  "gold": "rgb(255, 215, 0)",
  "gold1": "rgb(255, 215, 0)",
  "gold2": "rgb(238, 201, 0)",
  "gold3": "rgb(205, 173, 0)",
  "gold4": "rgb(139, 117, 0)",
  "goldenrod": "rgb(218, 165, 32)",
  "goldenrod1": "rgb(255, 193, 37)",
  "goldenrod2": "rgb(238, 180, 34)",
  "goldenrod3": "rgb(205, 155, 29)",
  "goldenrod4": "rgb(139, 105, 20)",
  "gray": "rgb(190, 190, 190)",
  "gray0": "rgb(0, 0, 0)",
  "gray1": "rgb(3, 3, 3)",
  "gray10": "rgb(26, 26, 26)",
  "gray100": "rgb(255, 255, 255)",
  "gray11": "rgb(28, 28, 28)",
  "gray12": "rgb(31, 31, 31)",
  "gray13": "rgb(33, 33, 33)",
  "gray14": "rgb(36, 36, 36)",
  "gray15": "rgb(38, 38, 38)",
  "gray16": "rgb(41, 41, 41)",
  "gray17": "rgb(43, 43, 43)",
  "gray18": "rgb(46, 46, 46)",
  "gray19": "rgb(48, 48, 48)",
  "gray2": "rgb(5, 5, 5)",
  "gray20": "rgb(51, 51, 51)",
  "gray21": "rgb(54, 54, 54)",
  "gray22": "rgb(56, 56, 56)",
  "gray23": "rgb(59, 59, 59)",
  "gray24": "rgb(61, 61, 61)",
  "gray25": "rgb(64, 64, 64)",
  "gray26": "rgb(66, 66, 66)",
  "gray27": "rgb(69, 69, 69)",
  "gray28": "rgb(71, 71, 71)",
  "gray29": "rgb(74, 74, 74)",
  "gray3": "rgb(8, 8, 8)",
  "gray30": "rgb(77, 77, 77)",
  "gray31": "rgb(79, 79, 79)",
  "gray32": "rgb(82, 82, 82)",
  "gray33": "rgb(84, 84, 84)",
  "gray34": "rgb(87, 87, 87)",
  "gray35": "rgb(89, 89, 89)",
  "gray36": "rgb(92, 92, 92)",
  "gray37": "rgb(94, 94, 94)",
  "gray38": "rgb(97, 97, 97)",
  "gray39": "rgb(99, 99, 99)",
  "gray4": "rgb(10, 10, 10)",
  "gray40": "rgb(102, 102, 102)",
  "gray41": "rgb(105, 105, 105)",
  "gray42": "rgb(107, 107, 107)",
  "gray43": "rgb(110, 110, 110)",
  "gray44": "rgb(112, 112, 112)",
  "gray45": "rgb(115, 115, 115)",
  "gray46": "rgb(117, 117, 117)",
  "gray47": "rgb(120, 120, 120)",
  "gray48": "rgb(122, 122, 122)",
  "gray49": "rgb(125, 125, 125)",
  "gray5": "rgb(13, 13, 13)",
  "gray50": "rgb(127, 127, 127)",
  "gray51": "rgb(130, 130, 130)",
  "gray52": "rgb(133, 133, 133)",
  "gray53": "rgb(135, 135, 135)",
  "gray54": "rgb(138, 138, 138)",
  "gray55": "rgb(140, 140, 140)",
  "gray56": "rgb(143, 143, 143)",
  "gray57": "rgb(145, 145, 145)",
  "gray58": "rgb(148, 148, 148)",
  "gray59": "rgb(150, 150, 150)",
  "gray6": "rgb(15, 15, 15)",
  "gray60": "rgb(153, 153, 153)",
  "gray61": "rgb(156, 156, 156)",
  "gray62": "rgb(158, 158, 158)",
  "gray63": "rgb(161, 161, 161)",
  "gray64": "rgb(163, 163, 163)",
  "gray65": "rgb(166, 166, 166)",
  "gray66": "rgb(168, 168, 168)",
  "gray67": "rgb(171, 171, 171)",
  "gray68": "rgb(173, 173, 173)",
  "gray69": "rgb(176, 176, 176)",
  "gray7": "rgb(18, 18, 18)",
  "gray70": "rgb(179, 179, 179)",
  "gray71": "rgb(181, 181, 181)",
  "gray72": "rgb(184, 184, 184)",
  "gray73": "rgb(186, 186, 186)",
  "gray74": "rgb(189, 189, 189)",
  "gray75": "rgb(191, 191, 191)",
  "gray76": "rgb(194, 194, 194)",
  "gray77": "rgb(196, 196, 196)",
  "gray78": "rgb(199, 199, 199)",
  "gray79": "rgb(201, 201, 201)",
  "gray8": "rgb(20, 20, 20)",
  "gray80": "rgb(204, 204, 204)",
  "gray81": "rgb(207, 207, 207)",
  "gray82": "rgb(209, 209, 209)",
  "gray83": "rgb(212, 212, 212)",
  "gray84": "rgb(214, 214, 214)",
  "gray85": "rgb(217, 217, 217)",
  "gray86": "rgb(219, 219, 219)",
  "gray87": "rgb(222, 222, 222)",
  "gray88": "rgb(224, 224, 224)",
  "gray89": "rgb(227, 227, 227)",
  "gray9": "rgb(23, 23, 23)",
  "gray90": "rgb(229, 229, 229)",
  "gray91": "rgb(232, 232, 232)",
  "gray92": "rgb(235, 235, 235)",
  "gray93": "rgb(237, 237, 237)",
  "gray94": "rgb(240, 240, 240)",
  "gray95": "rgb(242, 242, 242)",
  "gray96": "rgb(245, 245, 245)",
  "gray97": "rgb(247, 247, 247)",
  "gray98": "rgb(250, 250, 250)",
  "gray99": "rgb(252, 252, 252)",
  "green": "rgb(0, 255, 0)",
  "green1": "rgb(0, 255, 0)",
  "green2": "rgb(0, 238, 0)",
  "green3": "rgb(0, 205, 0)",
  "green4": "rgb(0, 139, 0)",
  "greenyellow": "rgb(173, 255, 47)",
  "grey": "rgb(190, 190, 190)",
  "grey0": "rgb(0, 0, 0)",
  "grey1": "rgb(3, 3, 3)",
  "grey10": "rgb(26, 26, 26)",
  "grey100": "rgb(255, 255, 255)",
  "grey11": "rgb(28, 28, 28)",
  "grey12": "rgb(31, 31, 31)",
  "grey13": "rgb(33, 33, 33)",
  "grey14": "rgb(36, 36, 36)",
  "grey15": "rgb(38, 38, 38)",
  "grey16": "rgb(41, 41, 41)",
  "grey17": "rgb(43, 43, 43)",
  "grey18": "rgb(46, 46, 46)",
  "grey19": "rgb(48, 48, 48)",
  "grey2": "rgb(5, 5, 5)",
  "grey20": "rgb(51, 51, 51)",
  "grey21": "rgb(54, 54, 54)",
  "grey22": "rgb(56, 56, 56)",
  "grey23": "rgb(59, 59, 59)",
  "grey24": "rgb(61, 61, 61)",
  "grey25": "rgb(64, 64, 64)",
  "grey26": "rgb(66, 66, 66)",
  "grey27": "rgb(69, 69, 69)",
  "grey28": "rgb(71, 71, 71)",
  "grey29": "rgb(74, 74, 74)",
  "grey3": "rgb(8, 8, 8)",
  "grey30": "rgb(77, 77, 77)",
  "grey31": "rgb(79, 79, 79)",
  "grey32": "rgb(82, 82, 82)",
  "grey33": "rgb(84, 84, 84)",
  "grey34": "rgb(87, 87, 87)",
  "grey35": "rgb(89, 89, 89)",
  "grey36": "rgb(92, 92, 92)",
  "grey37": "rgb(94, 94, 94)",
  "grey38": "rgb(97, 97, 97)",
  "grey39": "rgb(99, 99, 99)",
  "grey4": "rgb(10, 10, 10)",
  "grey40": "rgb(102, 102, 102)",
  "grey41": "rgb(105, 105, 105)",
  "grey42": "rgb(107, 107, 107)",
  "grey43": "rgb(110, 110, 110)",
  "grey44": "rgb(112, 112, 112)",
  "grey45": "rgb(115, 115, 115)",
  "grey46": "rgb(117, 117, 117)",
  "grey47": "rgb(120, 120, 120)",
  "grey48": "rgb(122, 122, 122)",
  "grey49": "rgb(125, 125, 125)",
  "grey5": "rgb(13, 13, 13)",
  "grey50": "rgb(127, 127, 127)",
  "grey51": "rgb(130, 130, 130)",
  "grey52": "rgb(133, 133, 133)",
  "grey53": "rgb(135, 135, 135)",
  "grey54": "rgb(138, 138, 138)",
  "grey55": "rgb(140, 140, 140)",
  "grey56": "rgb(143, 143, 143)",
  "grey57": "rgb(145, 145, 145)",
  "grey58": "rgb(148, 148, 148)",
  "grey59": "rgb(150, 150, 150)",
  "grey6": "rgb(15, 15, 15)",
  "grey60": "rgb(153, 153, 153)",
  "grey61": "rgb(156, 156, 156)",
  "grey62": "rgb(158, 158, 158)",
  "grey63": "rgb(161, 161, 161)",
  "grey64": "rgb(163, 163, 163)",
  "grey65": "rgb(166, 166, 166)",
  "grey66": "rgb(168, 168, 168)",
  "grey67": "rgb(171, 171, 171)",
  "grey68": "rgb(173, 173, 173)",
  "grey69": "rgb(176, 176, 176)",
  "grey7": "rgb(18, 18, 18)",
  "grey70": "rgb(179, 179, 179)",
  "grey71": "rgb(181, 181, 181)",
  "grey72": "rgb(184, 184, 184)",
  "grey73": "rgb(186, 186, 186)",
  "grey74": "rgb(189, 189, 189)",
  "grey75": "rgb(191, 191, 191)",
  "grey76": "rgb(194, 194, 194)",
  "grey77": "rgb(196, 196, 196)",
  "grey78": "rgb(199, 199, 199)",
  "grey79": "rgb(201, 201, 201)",
  "grey8": "rgb(20, 20, 20)",
  "grey80": "rgb(204, 204, 204)",
  "grey81": "rgb(207, 207, 207)",
  "grey82": "rgb(209, 209, 209)",
  "grey83": "rgb(212, 212, 212)",
  "grey84": "rgb(214, 214, 214)",
  "grey85": "rgb(217, 217, 217)",
  "grey86": "rgb(219, 219, 219)",
  "grey87": "rgb(222, 222, 222)",
  "grey88": "rgb(224, 224, 224)",
  "grey89": "rgb(227, 227, 227)",
  "grey9": "rgb(23, 23, 23)",
  "grey90": "rgb(229, 229, 229)",
  "grey91": "rgb(232, 232, 232)",
  "grey92": "rgb(235, 235, 235)",
  "grey93": "rgb(237, 237, 237)",
  "grey94": "rgb(240, 240, 240)",
  "grey95": "rgb(242, 242, 242)",
  "grey96": "rgb(245, 245, 245)",
  "grey97": "rgb(247, 247, 247)",
  "grey98": "rgb(250, 250, 250)",
  "grey99": "rgb(252, 252, 252)",
  "honeydew": "rgb(240, 255, 240)",
  "honeydew1": "rgb(240, 255, 240)",
  "honeydew2": "rgb(224, 238, 224)",
  "honeydew3": "rgb(193, 205, 193)",
  "honeydew4": "rgb(131, 139, 131)",
  "hotpink": "rgb(255, 105, 180)",
  "hotpink1": "rgb(255, 110, 180)",
  "hotpink2": "rgb(238, 106, 167)",
  "hotpink3": "rgb(205, 96, 144)",
  "hotpink4": "rgb(139, 58, 98)",
  "indianred": "rgb(205, 92, 92)",
  "indianred1": "rgb(255, 106, 106)",
  "indianred2": "rgb(238, 99, 99)",
  "indianred3": "rgb(205, 85, 85)",
  "indianred4": "rgb(139, 58, 58)",
  "ivory": "rgb(255, 255, 240)",
  "ivory1": "rgb(255, 255, 240)",
  "ivory2": "rgb(238, 238, 224)",
  "ivory3": "rgb(205, 205, 193)",
  "ivory4": "rgb(139, 139, 131)",
  "khaki": "rgb(240, 230, 140)",
  "khaki1": "rgb(255, 246, 143)",
  "khaki2": "rgb(238, 230, 133)",
  "khaki3": "rgb(205, 198, 115)",
  "khaki4": "rgb(139, 134, 78)",
  "lavender": "rgb(230, 230, 250)",
  "lavenderblush": "rgb(255, 240, 245)",
  "lavenderblush1": "rgb(255, 240, 245)",
  "lavenderblush2": "rgb(238, 224, 229)",
  "lavenderblush3": "rgb(205, 193, 197)",
  "lavenderblush4": "rgb(139, 131, 134)",
  "lawngreen": "rgb(124, 252, 0)",
  "lemonchiffon": "rgb(255, 250, 205)",
  "lemonchiffon1": "rgb(255, 250, 205)",
  "lemonchiffon2": "rgb(238, 233, 191)",
  "lemonchiffon3": "rgb(205, 201, 165)",
  "lemonchiffon4": "rgb(139, 137, 112)",
  "lightblue": "rgb(173, 216, 230)",
  "lightblue1": "rgb(191, 239, 255)",
  "lightblue2": "rgb(178, 223, 238)",
  "lightblue3": "rgb(154, 192, 205)",
  "lightblue4": "rgb(104, 131, 139)",
  "lightcoral": "rgb(240, 128, 128)",
  "lightcyan": "rgb(224, 255, 255)",
  "lightcyan1": "rgb(224, 255, 255)",
  "lightcyan2": "rgb(209, 238, 238)",
  "lightcyan3": "rgb(180, 205, 205)",
  "lightcyan4": "rgb(122, 139, 139)",
  "lightgoldenrod": "rgb(238, 221, 130)",
  "lightgoldenrod1": "rgb(255, 236, 139)",
  "lightgoldenrod2": "rgb(238, 220, 130)",
  "lightgoldenrod3": "rgb(205, 190, 112)",
  "lightgoldenrod4": "rgb(139, 129, 76)",
  "lightgoldenrodyellow": "rgb(250, 250, 210)",
  "lightgray": "rgb(211, 211, 211)",
  "lightgreen": "rgb(144, 238, 144)",
  "lightgrey": "rgb(211, 211, 211)",
  "lightpink": "rgb(255, 182, 193)",
  "lightpink1": "rgb(255, 174, 185)",
  "lightpink2": "rgb(238, 162, 173)",
  "lightpink3": "rgb(205, 140, 149)",
  "lightpink4": "rgb(139, 95, 101)",
  "lightsalmon": "rgb(255, 160, 122)",
  "lightsalmon1": "rgb(255, 160, 122)",
  "lightsalmon2": "rgb(238, 149, 114)",
  "lightsalmon3": "rgb(205, 129, 98)",
  "lightsalmon4": "rgb(139, 87, 66)",
  "lightseagreen": "rgb(32, 178, 170)",
  "lightskyblue": "rgb(135, 206, 250)",
  "lightskyblue1": "rgb(176, 226, 255)",
  "lightskyblue2": "rgb(164, 211, 238)",
  "lightskyblue3": "rgb(141, 182, 205)",
  "lightskyblue4": "rgb(96, 123, 139)",
  "lightslateblue": "rgb(132, 112, 255)",
  "lightslategray": "rgb(119, 136, 153)",
  "lightslategrey": "rgb(119, 136, 153)",
  "lightsteelblue": "rgb(176, 196, 222)",
  "lightsteelblue1": "rgb(202, 225, 255)",
  "lightsteelblue2": "rgb(188, 210, 238)",
  "lightsteelblue3": "rgb(162, 181, 205)",
  "lightsteelblue4": "rgb(110, 123, 139)",
  "lightyellow": "rgb(255, 255, 224)",
  "lightyellow1": "rgb(255, 255, 224)",
  "lightyellow2": "rgb(238, 238, 209)",
  "lightyellow3": "rgb(205, 205, 180)",
  "lightyellow4": "rgb(139, 139, 122)",
  "limegreen": "rgb(50, 205, 50)",
  "linen": "rgb(250, 240, 230)",
  "magenta": "rgb(255, 0, 255)",
  "magenta1": "rgb(255, 0, 255)",
  "magenta2": "rgb(238, 0, 238)",
  "magenta3": "rgb(205, 0, 205)",
  "magenta4": "rgb(139, 0, 139)",
  "maroon": "rgb(176, 48, 96)",
  "maroon1": "rgb(255, 52, 179)",
  "maroon2": "rgb(238, 48, 167)",
  "maroon3": "rgb(205, 41, 144)",
  "maroon4": "rgb(139, 28, 98)",
  "mediumaquamarine": "rgb(102, 205, 170)",
  "mediumblue": "rgb(0, 0, 205)",
  "mediumorchid": "rgb(186, 85, 211)",
  "mediumorchid1": "rgb(224, 102, 255)",
  "mediumorchid2": "rgb(209, 95, 238)",
  "mediumorchid3": "rgb(180, 82, 205)",
  "mediumorchid4": "rgb(122, 55, 139)",
  "mediumpurple": "rgb(147, 112, 219)",
  "mediumpurple1": "rgb(171, 130, 255)",
  "mediumpurple2": "rgb(159, 121, 238)",
  "mediumpurple3": "rgb(137, 104, 205)",
  "mediumpurple4": "rgb(93, 71, 139)",
  "mediumseagreen": "rgb(60, 179, 113)",
  "mediumslateblue": "rgb(123, 104, 238)",
  "mediumspringgreen": "rgb(0, 250, 154)",
  "mediumturquoise": "rgb(72, 209, 204)",
  "mediumvioletred": "rgb(199, 21, 133)",
  "midnightblue": "rgb(25, 25, 112)",
  "mintcream": "rgb(245, 255, 250)",
  "mistyrose": "rgb(255, 228, 225)",
  "mistyrose1": "rgb(255, 228, 225)",
  "mistyrose2": "rgb(238, 213, 210)",
  "mistyrose3": "rgb(205, 183, 181)",
  "mistyrose4": "rgb(139, 125, 123)",
  "moccasin": "rgb(255, 228, 181)",
  "navajowhite": "rgb(255, 222, 173)",
  "navajowhite1": "rgb(255, 222, 173)",
  "navajowhite2": "rgb(238, 207, 161)",
  "navajowhite3": "rgb(205, 179, 139)",
  "navajowhite4": "rgb(139, 121, 94)",
  "navy": "rgb(0, 0, 128)",
  "navyblue": "rgb(0, 0, 128)",
  "oldlace": "rgb(253, 245, 230)",
  "olivedrab": "rgb(107, 142, 35)",
  "olivedrab1": "rgb(192, 255, 62)",
  "olivedrab2": "rgb(179, 238, 58)",
  "olivedrab3": "rgb(154, 205, 50)",
  "olivedrab4": "rgb(105, 139, 34)",
  "orange": "rgb(255, 165, 0)",
  "orange1": "rgb(255, 165, 0)",
  "orange2": "rgb(238, 154, 0)",
  "orange3": "rgb(205, 133, 0)",
  "orange4": "rgb(139, 90, 0)",
  "orangered": "rgb(255, 69, 0)",
  "orangered1": "rgb(255, 69, 0)",
  "orangered2": "rgb(238, 64, 0)",
  "orangered3": "rgb(205, 55, 0)",
  "orangered4": "rgb(139, 37, 0)",
  "orchid": "rgb(218, 112, 214)",
  "orchid1": "rgb(255, 131, 250)",
  "orchid2": "rgb(238, 122, 233)",
  "orchid3": "rgb(205, 105, 201)",
  "orchid4": "rgb(139, 71, 137)",
  "palegoldenrod": "rgb(238, 232, 170)",
  "palegreen": "rgb(152, 251, 152)",
  "palegreen1": "rgb(154, 255, 154)",
  "palegreen2": "rgb(144, 238, 144)",
  "palegreen3": "rgb(124, 205, 124)",
  "palegreen4": "rgb(84, 139, 84)",
  "paleturquoise": "rgb(175, 238, 238)",
  "paleturquoise1": "rgb(187, 255, 255)",
  "paleturquoise2": "rgb(174, 238, 238)",
  "paleturquoise3": "rgb(150, 205, 205)",
  "paleturquoise4": "rgb(102, 139, 139)",
  "palevioletred": "rgb(219, 112, 147)",
  "palevioletred1": "rgb(255, 130, 171)",
  "palevioletred2": "rgb(238, 121, 159)",
  "palevioletred3": "rgb(205, 104, 137)",
  "palevioletred4": "rgb(139, 71, 93)",
  "papayawhip": "rgb(255, 239, 213)",
  "peachpuff": "rgb(255, 218, 185)",
  "peachpuff1": "rgb(255, 218, 185)",
  "peachpuff2": "rgb(238, 203, 173)",
  "peachpuff3": "rgb(205, 175, 149)",
  "peachpuff4": "rgb(139, 119, 101)",
  "peru": "rgb(205, 133, 63)",
  "pink": "rgb(255, 192, 203)",
  "pink1": "rgb(255, 181, 197)",
  "pink2": "rgb(238, 169, 184)",
  "pink3": "rgb(205, 145, 158)",
  "pink4": "rgb(139, 99, 108)",
  "plum": "rgb(221, 160, 221)",
  "plum1": "rgb(255, 187, 255)",
  "plum2": "rgb(238, 174, 238)",
  "plum3": "rgb(205, 150, 205)",
  "plum4": "rgb(139, 102, 139)",
  "powderblue": "rgb(176, 224, 230)",
  "purple": "rgb(160, 32, 240)",
  "purple1": "rgb(155, 48, 255)",
  "purple2": "rgb(145, 44, 238)",
  "purple3": "rgb(125, 38, 205)",
  "purple4": "rgb(85, 26, 139)",
  "red": "rgb(255, 0, 0)",
  "red1": "rgb(255, 0, 0)",
  "red2": "rgb(238, 0, 0)",
  "red3": "rgb(205, 0, 0)",
  "red4": "rgb(139, 0, 0)",
  "rosybrown": "rgb(188, 143, 143)",
  "rosybrown1": "rgb(255, 193, 193)",
  "rosybrown2": "rgb(238, 180, 180)",
  "rosybrown3": "rgb(205, 155, 155)",
  "rosybrown4": "rgb(139, 105, 105)",
  "royalblue": "rgb(65, 105, 225)",
  "royalblue1": "rgb(72, 118, 255)",
  "royalblue2": "rgb(67, 110, 238)",
  "royalblue3": "rgb(58, 95, 205)",
  "royalblue4": "rgb(39, 64, 139)",
  "saddlebrown": "rgb(139, 69, 19)",
  "salmon": "rgb(250, 128, 114)",
  "salmon1": "rgb(255, 140, 105)",
  "salmon2": "rgb(238, 130, 98)",
  "salmon3": "rgb(205, 112, 84)",
  "salmon4": "rgb(139, 76, 57)",
  "sandybrown": "rgb(244, 164, 96)",
  "seagreen": "rgb(46, 139, 87)",
  "seagreen1": "rgb(84, 255, 159)",
  "seagreen2": "rgb(78, 238, 148)",
  "seagreen3": "rgb(67, 205, 128)",
  "seagreen4": "rgb(46, 139, 87)",
  "seashell": "rgb(255, 245, 238)",
  "seashell1": "rgb(255, 245, 238)",
  "seashell2": "rgb(238, 229, 222)",
  "seashell3": "rgb(205, 197, 191)",
  "seashell4": "rgb(139, 134, 130)",
  "sienna": "rgb(160, 82, 45)",
  "sienna1": "rgb(255, 130, 71)",
  "sienna2": "rgb(238, 121, 66)",
  "sienna3": "rgb(205, 104, 57)",
  "sienna4": "rgb(139, 71, 38)",
  "skyblue": "rgb(135, 206, 235)",
  "skyblue1": "rgb(135, 206, 255)",
  "skyblue2": "rgb(126, 192, 238)",
  "skyblue3": "rgb(108, 166, 205)",
  "skyblue4": "rgb(74, 112, 139)",
  "slateblue": "rgb(106, 90, 205)",
  "slateblue1": "rgb(131, 111, 255)",
  "slateblue2": "rgb(122, 103, 238)",
  "slateblue3": "rgb(105, 89, 205)",
  "slateblue4": "rgb(71, 60, 139)",
  "slategray": "rgb(112, 128, 144)",
  "slategray1": "rgb(198, 226, 255)",
  "slategray2": "rgb(185, 211, 238)",
  "slategray3": "rgb(159, 182, 205)",
  "slategray4": "rgb(108, 123, 139)",
  "slategrey": "rgb(112, 128, 144)",
  "snow": "rgb(255, 250, 250)",
  "snow1": "rgb(255, 250, 250)",
  "snow2": "rgb(238, 233, 233)",
  "snow3": "rgb(205, 201, 201)",
  "snow4": "rgb(139, 137, 137)",
  "springgreen": "rgb(0, 255, 127)",
  "springgreen1": "rgb(0, 255, 127)",
  "springgreen2": "rgb(0, 238, 118)",
  "springgreen3": "rgb(0, 205, 102)",
  "springgreen4": "rgb(0, 139, 69)",
  "steelblue": "rgb(70, 130, 180)",
  "steelblue1": "rgb(99, 184, 255)",
  "steelblue2": "rgb(92, 172, 238)",
  "steelblue3": "rgb(79, 148, 205)",
  "steelblue4": "rgb(54, 100, 139)",
  "tan": "rgb(210, 180, 140)",
  "tan1": "rgb(255, 165, 79)",
  "tan2": "rgb(238, 154, 73)",
  "tan3": "rgb(205, 133, 63)",
  "tan4": "rgb(139, 90, 43)",
  "thistle": "rgb(216, 191, 216)",
  "thistle1": "rgb(255, 225, 255)",
  "thistle2": "rgb(238, 210, 238)",
  "thistle3": "rgb(205, 181, 205)",
  "thistle4": "rgb(139, 123, 139)",
  "tomato": "rgb(255, 99, 71)",
  "tomato1": "rgb(255, 99, 71)",
  "tomato2": "rgb(238, 92, 66)",
  "tomato3": "rgb(205, 79, 57)",
  "tomato4": "rgb(139, 54, 38)",
  "turquoise": "rgb(64, 224, 208)",
  "turquoise1": "rgb(0, 245, 255)",
  "turquoise2": "rgb(0, 229, 238)",
  "turquoise3": "rgb(0, 197, 205)",
  "turquoise4": "rgb(0, 134, 139)",
  "violet": "rgb(238, 130, 238)",
  "violetred": "rgb(208, 32, 144)",
  "violetred1": "rgb(255, 62, 150)",
  "violetred2": "rgb(238, 58, 140)",
  "violetred3": "rgb(205, 50, 120)",
  "violetred4": "rgb(139, 34, 82)",
  "wheat": "rgb(245, 222, 179)",
  "wheat1": "rgb(255, 231, 186)",
  "wheat2": "rgb(238, 216, 174)",
  "wheat3": "rgb(205, 186, 150)",
  "wheat4": "rgb(139, 126, 102)",
  "white": "rgb(255, 255, 255)",
  "whitesmoke": "rgb(245, 245, 245)",
  "yellow": "rgb(255, 255, 0)",
  "yellow1": "rgb(255, 255, 0)",
  "yellow2": "rgb(238, 238, 0)",
  "yellow3": "rgb(205, 205, 0)",
  "yellow4": "rgb(139, 139, 0)",
  "yellowgreen": "rgb(154, 205, 50)"
};
// SOURCE FILE: libdot/js/lib_f.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

/**
 * Grab bag of utility functions.
 */
lib.f = {};

/**
 * Create a unique enum value.
 *
 * @suppress {lintChecks}
 * @param {string} name A human friendly name for debugging.
 * @return {Object} A unique enum that won't compare equal to anything else.
 */
lib.f.createEnum = function(name) {
  // We use a String object as nothing else should be using them -- we want to
  // use string primitives normally.  But debuggers will include our name.
  // eslint-disable-next-line no-new-wrappers
  return new String(name);
};

/**
 * Replace variable references in a string.
 *
 * Variables are of the form %FUNCTION(VARNAME).  FUNCTION is an optional
 * escape function to apply to the value.
 *
 * For example
 *   lib.f.replaceVars("%(greeting), %encodeURIComponent(name)",
 *                     { greeting: "Hello",
 *                       name: "Google+" });
 *
 * Will result in "Hello, Google%2B".
 */
lib.f.replaceVars = function(str, vars) {
  return str.replace(/%([a-z]*)\(([^\)]+)\)/gi, function(match, fn, varname) {
      if (typeof vars[varname] == 'undefined')
        throw 'Unknown variable: ' + varname;

      var rv = vars[varname];

      if (fn in lib.f.replaceVars.functions) {
        rv = lib.f.replaceVars.functions[fn](rv);
      } else if (fn) {
        throw 'Unknown escape function: ' + fn;
      }

      return rv;
    });
};

/**
 * Functions that can be used with replaceVars.
 *
 * Clients can add to this list to extend lib.f.replaceVars().
 */
lib.f.replaceVars.functions = {
  encodeURI: encodeURI,
  encodeURIComponent: encodeURIComponent,
  escapeHTML: function(str) {
    var map = {
      '<': '&lt;',
      '>': '&gt;',
      '&': '&amp;',
      '"': '&quot;',
      "'": '&#39;'
    };

    return str.replace(/[<>&\"\']/g, (m) => map[m]);
  }
};

/**
 * Parse a query string into a hash.
 *
 * This takes a url query string in the form 'name1=value&name2=value' and
 * converts it into an object of the form { name1: 'value', name2: 'value' }.
 * If a given name appears multiple times in the query string, only the
 * last value will appear in the result.  If the name ends with [], it is
 * turned into an array.
 *
 * Names and values are passed through decodeURIComponent before being added
 * to the result object.
 *
 * @param {string} queryString The string to parse.  If it starts with a
 *     leading '?', the '?' will be ignored.
 */
lib.f.parseQuery = function(queryString) {
  if (queryString.startsWith('?'))
    queryString = queryString.substr(1);

  var rv = {};

  var pairs = queryString.split('&');
  for (var i = 0; i < pairs.length; i++) {
    var pair = pairs[i].split('=');
    let key = decodeURIComponent(pair[0]);
    let val = decodeURIComponent(pair[1]);

    if (key.endsWith('[]')) {
      // It's an array.
      key = key.slice(0, -2);
      // The key doesn't exist, or wasn't an array before.
      if (!(rv[key] instanceof Array))
        rv[key] = [];
      rv[key].push(val);
    } else {
      // It's a plain string.
      rv[key] = val;
    }
  }

  return rv;
};

lib.f.getURL = function(path) {
  if (lib.f.getURL.chromeSupported())
    return chrome.runtime.getURL(path);

  return path;
};

lib.f.getURL.chromeSupported = function() {
  return window.chrome && chrome.runtime && chrome.runtime.getURL;
};

/**
 * Clamp a given integer to a specified range.
 *
 * @param {integer} v The value to be clamped.
 * @param {integer} min The minimum acceptable value.
 * @param {integer} max The maximum acceptable value.
 */
lib.f.clamp = function(v, min, max) {
  if (v < min)
    return min;
  if (v > max)
    return max;
  return v;
};

/**
 * Left pad a number to a given length with leading zeros.
 *
 * @param {string|integer} number The number to pad.
 * @param {integer} length The desired length.
 * @return {string} The padded number as a string.
 */
lib.f.zpad = function(number, length) {
  return String(number).padStart(length, '0');
};

/**
 * Return a string containing a given number of space characters.
 *
 * This method maintains a static cache of the largest amount of whitespace
 * ever requested.  It shouldn't be used to generate an insanely huge amount of
 * whitespace.
 *
 * @param {integer} length The desired amount of whitespace.
 * @param {string} A string of spaces of the requested length.
 */
lib.f.getWhitespace = function(length) {
  if (length <= 0)
    return '';

  var f = this.getWhitespace;
  if (!f.whitespace)
    f.whitespace = '          ';

  while (length > f.whitespace.length) {
    f.whitespace += f.whitespace;
  }

  return f.whitespace.substr(0, length);
};

 /**
 * Ensure that a function is called within a certain time limit.
 *
 * Simple usage looks like this...
 *
 *  lib.registerInit(lib.f.alarm(onInit));
 *
 * This will log a warning to the console if onInit() is not invoked within
 * 5 seconds.
 *
 * If you're performing some operation that may take longer than 5 seconds you
 * can pass a duration in milliseconds as the optional second parameter.
 *
 * If you pass a string identifier instead of a callback function, you'll get a
 * wrapper generator rather than a single wrapper.  Each call to the
 * generator will return a wrapped version of the callback wired to
 * a shared timeout.  This is for cases where you want to ensure that at least
 * one of a set of callbacks is invoked before a timeout expires.
 *
 *   var alarm = lib.f.alarm('fetch object');
 *   lib.foo.fetchObject(alarm(onSuccess), alarm(onFailure));
 *
 * @param {function(*)} callback The function to wrap in an alarm.
 * @param {int} opt_ms Optional number of milliseconds to wait before raising
 *     an alarm.  Default is 5000 (5 seconds).
 * @return {function} If callback is a function then the return value will be
 *     the wrapped callback.  If callback is a string then the return value will
 *     be a function that generates new wrapped callbacks.
 */
lib.f.alarm = function(callback, opt_ms) {
  var ms = opt_ms || 5 * 1000;
  var stack = lib.f.getStack(1);

  return (function() {
    // This outer function is called immediately.  It's here to capture a new
    // scope for the timeout variable.

    // The 'timeout' variable is shared by this timeout function, and the
    // callback wrapper.
    var timeout = setTimeout(function() {
      var name = (typeof callback == 'string') ? name : callback.name;
      name = name ? (': ' + name) : '';
      console.warn('lib.f.alarm: timeout expired: ' + (ms / 1000) + 's' + name);
      console.log(stack);
      timeout = null;
    }, ms);

    var wrapperGenerator = function(callback) {
      return function() {
        if (timeout) {
          clearTimeout(timeout);
          timeout = null;
        }

        return callback.apply(null, arguments);
      };
    };

    if (typeof callback == 'string')
      return wrapperGenerator;

    return wrapperGenerator(callback);
  })();
};

/**
 * Return the current call stack after skipping a given number of frames.
 *
 * This method is intended to be used for debugging only.  It returns an
 * Object instead of an Array, because the console stringifies arrays by
 * default and that's not what we want.
 *
 * A typical call might look like...
 *
 *    console.log('Something wicked this way came', lib.f.getStack());
 *    //                         Notice the comma ^
 *
 * This would print the message to the js console, followed by an object
 * which can be clicked to reveal the stack.
 *
 * @param {number=} ignoreFrames How many inner stack frames to ignore.  The
 *     innermost 'getStack' call is always ignored.
 * @param {number=} count How many frames to return.
 */
lib.f.getStack = function(ignoreFrames = 0, count = undefined) {
  const stackArray = (new Error()).stack.split('\n');

  // Always ignore the Error() object and getStack call itself.
  // [0] = 'Error'
  // [1] = '    at Object.lib.f.getStack (file:///.../lib_f.js:267:23)'
  ignoreFrames += 2;

  const max = stackArray.length - ignoreFrames;
  if (count === undefined)
    count = max;
  else
    count = lib.f.clamp(count, 0, max);

  // Remove the leading spaces and "at" from each line:
  // '    at window.onload (file:///.../lib_test.js:11:18)'
  const stackObject = new Array();
  for (let i = ignoreFrames; i < count + ignoreFrames; ++i)
    stackObject.push(stackArray[i].replace(/^\s*at\s+/, ''));

  return stackObject;
};

/**
 * Divides the two numbers and floors the results, unless the remainder is less
 * than an incredibly small value, in which case it returns the ceiling.
 * This is useful when the number are truncated approximations of longer
 * values, and so doing division with these numbers yields a result incredibly
 * close to a whole number.
 *
 * @param {number} numerator
 * @param {number} denominator
 * @return {number}
 */
lib.f.smartFloorDivide = function(numerator,  denominator) {
  var val = numerator / denominator;
  var ceiling = Math.ceil(val);
  if (ceiling - val < .0001) {
    return ceiling;
  } else {
    return Math.floor(val);
  }
};

/**
 * Get a random integer in a range (inclusive).
 *
 * @param {number} min The lowest integer in the range.
 * @param {number} max The highest integer in the range.
 * @return {number} A random number between min & max.
 */
lib.f.randomInt = function(min, max) {
  return Math.floor(Math.random() * (max - min + 1)) + min;
};

/**
 * Get the current OS.
 *
 * @return {Promise<string>} A promise that resolves to a constant in
 *     runtime.PlatformOs.
 */
lib.f.getOs = function() {
  // Try the brower extensions API.
  if (window.browser && browser.runtime && browser.runtime.getPlatformInfo)
    return browser.runtime.getPlatformInfo().then((info) => info.os);

  // Use the native Chrome API if available.
  if (window.chrome && chrome.runtime && chrome.runtime.getPlatformInfo) {
    return new Promise((resolve, reject) =>
        chrome.runtime.getPlatformInfo((info) => resolve(info.os)));
  }

  // Fallback logic.  Capture the major OS's.  The rest should support the
  // browser API above.
  if (window.navigator && navigator.userAgent) {
    const ua = navigator.userAgent;
    if (ua.includes('Mac OS X'))
      return Promise.resolve('mac');
    else if (ua.includes('CrOS'))
      return Promise.resolve('cros');
    else if (ua.includes('Linux'))
      return Promise.resolve('linux');
    else if (ua.includes('Android'))
      return Promise.resolve('android');
    else if (ua.includes('Windows'))
      return Promise.resolve('windows');
  }

  // Still here?  No idea.
  return Promise.reject(null);
};

/**
 * Get the current Chrome milestone version.
 *
 * @return {number} The milestone number if we're running on Chrome, else NaN.
 */
lib.f.getChromeMilestone = function() {
  if (window.navigator && navigator.userAgent) {
    const ary = navigator.userAgent.match(/\sChrome\/(\d+)/);
    if (ary)
      return parseInt(ary[1]);
  }

  // Returning NaN will make all number comparisons fail.
  return NaN;
};

/**
 * Return the lastError string in the browser.
 *
 * This object might live in different locations, and it isn't always defined
 * (if there hasn't been a "last error").  Wrap all that ugliness here.
 *
 * @param {string=} defaultMsg The default message if no error is found.
 * @return {string} The last error message from the browser.
 */
lib.f.lastError = function(defaultMsg = null) {
  let lastError;
  if (window.browser && browser.runtime)
    lastError = browser.runtime.lastError;
  else if (window.chrome && chrome.runtime)
    lastError = chrome.runtime.lastError;

  if (lastError && lastError.message)
    return lastError.message;
  else
    return defaultMsg;
};

/**
 * Just like window.open, but enforce noopener.
 *
 * If we're not careful, the website we open will have access to use via its
 * window.opener field.  Newer browser support putting 'noopener' into the
 * features argument, but there are many which still don't.  So hack it.
 *
 * @param {string=} url The URL to point the new window to.
 * @param {string=} name The name of the new window.
 * @param {string=} features The window features to enable.
 * @return {Window} The newly opened window.
 */
lib.f.openWindow = function(url, name=undefined, features=undefined) {
  // We create the window first without the URL loaded.
  const win = window.open(undefined, name, features);

  // If the system is blocking window.open, don't crash.
  if (win !== null) {
    // Clear the opener setting before redirecting.
    win.opener = null;

    // Now it's safe to redirect.  Skip this step if the url is not set so we
    // mimic the window.open behavior more precisely.
    if (url) {
      win.location = url;
    }
  }

  return win;
};
// SOURCE FILE: libdot/js/lib_i18n.js
// Copyright 2018 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

/**
 * Wrappers over the browser i18n helpers.
 *
 * Arguably some of these functions should be l10n, but oh well.
 */
lib.i18n = {};

/**
 * Convenience shortcut to the browser i18n object.
 */
lib.i18n.browser_ =
    window.browser && browser.i18n ? browser.i18n :
    window.chrome && chrome.i18n ? chrome.i18n :
    null;

/**
 * Get the list of accepted UI languages.
 *
 * https://developer.mozilla.org/en-US/Add-ons/WebExtensions/API/i18n/getAcceptLanguages
 *
 * @param {function(Array)} callback Function to invoke with the results.  The
 *     parameter is a list of locale names.
 */
lib.i18n.getAcceptLanguages = function(callback) {
  if (lib.i18n.browser_) {
    lib.i18n.browser_.getAcceptLanguages(callback);
  } else {
    setTimeout(function() {
        callback([navigator.language.replace(/-/g, '_')]);
      }, 0);
  }
};

/**
 * Get a message by name, optionally replacing arguments too.
 *
 * https://developer.mozilla.org/en-US/Add-ons/WebExtensions/API/i18n/getMessage
 *
 * @param {string} msgname The id for this localized string.
 * @param {string[]=} substitutions Any replacements in the string.
 * @param {string=} fallback Translation if the message wasn't found.
 * @return {string} The translated message.
 */
lib.i18n.getMessage = function(msgname, substitutions = [], fallback = '') {
  // First let the native browser APIs handle everything for us.
  if (lib.i18n.browser_) {
    const message = lib.i18n.browser_.getMessage(msgname, substitutions);
    if (message)
      return message;
  }

  // Do our best to get something reasonable.
  return lib.i18n.replaceReferences(fallback, substitutions);
};

/**
 * Replace $1...$n references with the elements of the args array.
 *
 * This largely behaves like Chrome's getMessage helper.  The $# references are
 * always replaced/removed regardless of the specified substitutions.
 *
 * @param {string} msg String containing the message and argument references.
 * @param {string[]=} args Array containing the argument values.
 * @return {string} The message with replacements expanded.
 */
lib.i18n.replaceReferences = function(msg, args = []) {
  // The Chrome API allows a single substitution as a string rather than array.
  if (args === null) {
    args = [];
  }
  if (!(args instanceof Array)) {
    args = [args];
  }

  return msg.replace(/\$(\d+)/g, (m, index) => {
    return index <= args.length ? args[index - 1] : '';
  });
};
// SOURCE FILE: libdot/js/lib_message_manager.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

/**
 * MessageManager class handles internationalized strings.
 *
 * Note: chrome.i18n isn't sufficient because...
 *     1. There's a bug in chrome that makes it unavailable in iframes:
 *        https://crbug.com/130200
 *     2. The client code may not be packaged in a Chrome extension.
 *     3. The client code may be part of a library packaged in a third-party
 *        Chrome extension.
 *
 * @param {Array} languages List of languages to load, in the order they
 *     should be loaded.  Newer messages replace older ones.  'en' is
 *     automatically added as the first language if it is not already present.
 */
lib.MessageManager = function(languages) {
  this.languages_ = languages.map((el) => el.replace(/-/g, '_'));

  if (this.languages_.indexOf('en') == -1)
    this.languages_.unshift('en');

  this.messages = {};
};

/**
 * Add message definitions to the message manager.
 *
 * This takes an object of the same format of a Chrome messages.json file.  See
 * <https://developer.chrome.com/extensions/i18n-messages>.
 */
lib.MessageManager.prototype.addMessages = function(defs) {
  for (var key in defs) {
    var def = defs[key];

    if (!def.placeholders) {
      this.messages[key] = def.message;
    } else {
      // Replace "$NAME$" placeholders with "$1", etc.
      this.messages[key] = def.message.replace(
          /\$([a-z][^\s\$]+)\$/ig,
          function(m, name) {
            return defs[key].placeholders[name.toLowerCase()].content;
          });
    }
  }
};

/**
 * Load the first available language message bundle.
 *
 * @param {string} pattern A url pattern containing a "$1" where the locale
 *     name should go.
 * @param {function(Array,Array)} onComplete Function to be called when loading
 *     is complete.  The two arrays are the list of successful and failed
 *     locale names.  If the first parameter is length 0, no locales were
 *     loaded.
 */
lib.MessageManager.prototype.findAndLoadMessages = function(
    pattern, onComplete) {
  var languages = this.languages_.concat();
  var loaded = [];
  var failed = [];

  function onLanguageComplete(state) {
    if (state) {
      loaded = languages.shift();
    } else {
      failed = languages.shift();
    }

    if (languages.length) {
      tryNextLanguage();
    } else {
      onComplete(loaded, failed);
    }
  }

  var tryNextLanguage = function() {
    this.loadMessages(this.replaceReferences(pattern, languages),
                      onLanguageComplete.bind(this, true),
                      onLanguageComplete.bind(this, false));
  }.bind(this);

  tryNextLanguage();
};

/**
 * Load messages from a messages.json file.
 */
lib.MessageManager.prototype.loadMessages = function(
    url, onSuccess, opt_onError) {
  var xhr = new XMLHttpRequest();

  xhr.onload = () => {
    this.addMessages(JSON.parse(xhr.responseText));
    onSuccess();
  };
  if (opt_onError)
    xhr.onerror = () => opt_onError(xhr);

  xhr.open('GET', url);
  xhr.send();
};

/**
 * Per-instance copy of replaceReferences.
 */
lib.MessageManager.prototype.replaceReferences = lib.i18n.replaceReferences;

/**
 * Get a message by name, optionally replacing arguments too.
 *
 * @param {string} msgname String containing the name of the message to get.
 * @param {Array} opt_args Optional array containing the argument values.
 * @param {string} opt_default Optional value to return if the msgname is not
 *     found.  Returns the message name by default.
 */
lib.MessageManager.prototype.get = function(msgname, opt_args, opt_default) {
  // First try the integrated browser getMessage.  We prefer that over any
  // registered messages as only the browser supports translations.
  let message = lib.i18n.getMessage(msgname, opt_args);
  if (message)
    return message;

  // Look it up in the registered cache next.
  message = this.messages[msgname];
  if (!message) {
    console.warn('Unknown message: ' + msgname);
    message = opt_default === undefined ? msgname : opt_default;
    // Register the message with the default to avoid multiple warnings.
    this.messages[msgname] = message;
  }

  return this.replaceReferences(message, opt_args);
};

/**
 * Process all of the "i18n" html attributes found in a given dom fragment.
 *
 * The real work happens in processI18nAttribute.
 */
lib.MessageManager.prototype.processI18nAttributes = function(dom) {
  var nodes = dom.querySelectorAll('[i18n]');

  for (var i = 0; i < nodes.length; i++)
    this.processI18nAttribute(nodes[i]);
};

/**
 * Process the "i18n" attribute in the specified node.
 *
 * The i18n attribute should contain a JSON object.  The keys are taken to
 * be attribute names, and the values are message names.
 *
 * If the JSON object has a "_" (underscore) key, its value is used as the
 * textContent of the element.
 *
 * Message names can refer to other attributes on the same element with by
 * prefixing with a dollar sign.  For example...
 *
 *   <button id='send-button'
 *           i18n='{"aria-label": "$id", "_": "SEND_BUTTON_LABEL"}'
 *           ></button>
 *
 * The aria-label message name will be computed as "SEND_BUTTON_ARIA_LABEL".
 * Notice that the "id" attribute was appended to the target attribute, and
 * the result converted to UPPER_AND_UNDER style.
 */
lib.MessageManager.prototype.processI18nAttribute = function(node) {
  // Convert the "lower-and-dashes" attribute names into
  // "UPPER_AND_UNDER" style.
  const thunk = (str) => str.replace(/-/g, '_').toUpperCase();

  var i18n = node.getAttribute('i18n');
  if (!i18n)
    return;

  try {
    i18n = JSON.parse(i18n);
  } catch (ex) {
    console.error('Can\'t parse ' + node.tagName + '#' + node.id + ': ' + i18n);
    throw ex;
  }

  // Load all the messages specified in the i18n attributes.
  for (var key in i18n) {
    // The node attribute we'll be setting.
    var attr = key;

    var msgname = i18n[key];
    // For "=foo", re-use the referenced message name.
    if (msgname.startsWith('=')) {
      key = msgname.substr(1);
      msgname = i18n[key];
    }

    // For "$foo", calculate the message name.
    if (msgname.startsWith('$'))
      msgname = thunk(node.getAttribute(msgname.substr(1)) + '_' + key);

    // Finally load the message.
    var msg = this.get(msgname);
    if (attr == '_')
      node.textContent = msg;
    else
      node.setAttribute(attr, msg);
  }
};
// SOURCE FILE: libdot/js/lib_preference_manager.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

/**
 * Constructor for lib.PreferenceManager objects.
 *
 * These objects deal with persisting changes to stable storage and notifying
 * consumers when preferences change.
 *
 * It is intended that the backing store could be something other than HTML5
 * storage, but there aren't any use cases at the moment.  In the future there
 * may be a chrome api to store sync-able name/value pairs, and we'd want
 * that.
 *
 * @param {lib.Storage.*} storage The storage object to use as a backing
 *     store.
 * @param {string} opt_prefix The optional prefix to be used for all preference
 *     names.  The '/' character should be used to separate levels of hierarchy,
 *     if you're going to have that kind of thing.  If provided, the prefix
 *     should start with a '/'.  If not provided, it defaults to '/'.
 */
lib.PreferenceManager = function(storage, opt_prefix) {
  this.storage = storage;
  this.storageObserver_ = this.onStorageChange_.bind(this);

  this.isActive_ = false;
  this.activate();

  this.trace = false;

  var prefix = opt_prefix || '/';
  if (!prefix.endsWith('/'))
    prefix += '/';

  this.prefix = prefix;

  // Internal state for when we're doing a bulk import from JSON and we want
  // to elide redundant storage writes (for quota reasons).
  this.isImportingJson_ = false;

  this.prefRecords_ = {};
  this.globalObservers_ = [];

  this.childFactories_ = {};

  // Map of list-name to {map of child pref managers}
  // As in...
  //
  //  this.childLists_ = {
  //    'profile-ids': {
  //      'one': PreferenceManager,
  //      'two': PreferenceManager,
  //      ...
  //    },
  //
  //    'frob-ids': {
  //      ...
  //    }
  //  }
  this.childLists_ = {};
};

/**
 * Used internally to indicate that the current value of the preference should
 * be taken from the default value defined with the preference.
 *
 * Equality tests against this value MUST use '===' or '!==' to be accurate.
 */
lib.PreferenceManager.prototype.DEFAULT_VALUE = lib.f.createEnum('DEFAULT');

/**
 * An individual preference.
 *
 * These objects are managed by the PreferenceManager, you shouldn't need to
 * handle them directly.
 */
lib.PreferenceManager.Record = function(name, defaultValue) {
  this.name = name;
  this.defaultValue = defaultValue;
  this.currentValue = this.DEFAULT_VALUE;
  this.observers = [];
};

/**
 * A local copy of the DEFAULT_VALUE constant to make it less verbose.
 */
lib.PreferenceManager.Record.prototype.DEFAULT_VALUE =
    lib.PreferenceManager.prototype.DEFAULT_VALUE;

/**
 * Register a callback to be invoked when this preference changes.
 *
 * @param {function(value, string, lib.PreferenceManager} observer The function
 *     to invoke.  It will receive the new value, the name of the preference,
 *     and a reference to the PreferenceManager as parameters.
 */
lib.PreferenceManager.Record.prototype.addObserver = function(observer) {
  this.observers.push(observer);
};

/**
 * Unregister an observer callback.
 *
 * @param {function} observer A previously registered callback.
 */
lib.PreferenceManager.Record.prototype.removeObserver = function(observer) {
  var i = this.observers.indexOf(observer);
  if (i >= 0)
    this.observers.splice(i, 1);
};

/**
 * Fetch the value of this preference.
 */
lib.PreferenceManager.Record.prototype.get = function() {
  if (this.currentValue === this.DEFAULT_VALUE) {
    if (/^(string|number)$/.test(typeof this.defaultValue))
      return this.defaultValue;

    if (typeof this.defaultValue == 'object') {
      // We want to return a COPY of the default value so that users can
      // modify the array or object without changing the default value.
      return JSON.parse(JSON.stringify(this.defaultValue));
    }

    return this.defaultValue;
  }

  return this.currentValue;
};

/**
 * Stop this preference manager from tracking storage changes.
 *
 * Call this if you're going to swap out one preference manager for another so
 * that you don't get notified about irrelevant changes.
 */
lib.PreferenceManager.prototype.deactivate = function() {
  if (!this.isActive_)
    throw new Error('Not activated');

  this.isActive_ = false;
  this.storage.removeObserver(this.storageObserver_);
};

/**
 * Start tracking storage changes.
 *
 * If you previously deactivated this preference manager, you can reactivate it
 * with this method.  You don't need to call this at initialization time, as
 * it's automatically called as part of the constructor.
 */
lib.PreferenceManager.prototype.activate = function() {
  if (this.isActive_)
    throw new Error('Already activated');

  this.isActive_ = true;
  this.storage.addObserver(this.storageObserver_);
};

/**
 * Read the backing storage for these preferences.
 *
 * You should do this once at initialization time to prime the local cache
 * of preference values.  The preference manager will monitor the backing
 * storage for changes, so you should not need to call this more than once.
 *
 * This function recursively reads storage for all child preference managers as
 * well.
 *
 * This function is asynchronous, if you need to read preference values, you
 * *must* wait for the callback.
 *
 * @param {function()} opt_callback Optional function to invoke when the read
 *     has completed.
 */
lib.PreferenceManager.prototype.readStorage = function(opt_callback) {
  var pendingChildren = 0;

  function onChildComplete() {
    if (--pendingChildren == 0 && opt_callback)
      opt_callback();
  }

  var keys = Object.keys(this.prefRecords_).map((el) => this.prefix + el);

  if (this.trace)
    console.log('Preferences read: ' + this.prefix);

  this.storage.getItems(keys, function(items) {
      var prefixLength = this.prefix.length;

      for (var key in items) {
        var value = items[key];
        var name = key.substr(prefixLength);
        var needSync = (name in this.childLists_ &&
                        (JSON.stringify(value) !=
                         JSON.stringify(this.prefRecords_[name].currentValue)));

        this.prefRecords_[name].currentValue = value;

        if (needSync) {
          pendingChildren++;
          this.syncChildList(name, onChildComplete);
        }
      }

      if (pendingChildren == 0 && opt_callback)
        setTimeout(opt_callback);
    }.bind(this));
};

/**
 * Define a preference.
 *
 * This registers a name, default value, and onChange handler for a preference.
 *
 * @param {string} name The name of the preference.  This will be prefixed by
 *     the prefix of this PreferenceManager before written to local storage.
 * @param {string|number|boolean|Object|Array|null} value The default value of
 *     this preference.  Anything that can be represented in JSON is a valid
 *     default value.
 * @param {function(value, string, lib.PreferenceManager} opt_observer A
 *     function to invoke when the preference changes.  It will receive the new
 *     value, the name of the preference, and a reference to the
 *     PreferenceManager as parameters.
 */
lib.PreferenceManager.prototype.definePreference = function(
    name, value, opt_onChange) {

  var record = this.prefRecords_[name];
  if (record) {
    this.changeDefault(name, value);
  } else {
    record = this.prefRecords_[name] =
        new lib.PreferenceManager.Record(name, value);
  }

  if (opt_onChange)
    record.addObserver(opt_onChange);
};

/**
 * Define multiple preferences with a single function call.
 *
 * @param {Array} defaults An array of 3-element arrays.  Each three element
 *     array should contain the [key, value, onChange] parameters for a
 *     preference.
 */
lib.PreferenceManager.prototype.definePreferences = function(defaults) {
  for (var i = 0; i < defaults.length; i++) {
    this.definePreference(defaults[i][0], defaults[i][1], defaults[i][2]);
  }
};

/**
 * Define an ordered list of child preferences.
 *
 * Child preferences are different from just storing an array of JSON objects
 * in that each child is an instance of a preference manager.  This means you
 * can observe changes to individual child preferences, and get some validation
 * that you're not reading or writing to an undefined child preference value.
 *
 * @param {string} listName A name for the list of children.  This must be
 *     unique in this preference manager.  The listName will become a
 *     preference on this PreferenceManager used to store the ordered list of
 *     child ids.  It is also used in get/add/remove operations to identify the
 *     list of children to operate on.
 * @param {function} childFactory A function that will be used to generate
 *     instances of these children.  The factory function will receive the
 *     parent lib.PreferenceManager object and a unique id for the new child
 *     preferences.
 */
lib.PreferenceManager.prototype.defineChildren = function(
    listName, childFactory) {

  // Define a preference to hold the ordered list of child ids.
  this.definePreference(listName, [],
                        this.onChildListChange_.bind(this, listName));
  this.childFactories_[listName] = childFactory;
  this.childLists_[listName] = {};
};

/**
 * Register to observe preference changes.
 *
 * @param {Function} global A callback that will happen for every preference.
 *     Pass null if you don't need one.
 * @param {Object} map A map of preference specific callbacks.  Pass null if
 *     you don't need any.
 */
lib.PreferenceManager.prototype.addObservers = function(global, map) {
  if (global && typeof global != 'function')
    throw new Error('Invalid param: globals');

  if (global)
    this.globalObservers_.push(global);

  if (!map)
    return;

  for (var name in map) {
    if (!(name in this.prefRecords_))
      throw new Error('Unknown preference: ' + name);

    this.prefRecords_[name].addObserver(map[name]);
  }
};

/**
 * Dispatch the change observers for all known preferences.
 *
 * It may be useful to call this after readStorage completes, in order to
 * get application state in sync with user preferences.
 *
 * This can be used if you've changed a preference manager out from under
 * a live object, for example when switching to a different prefix.
 */
lib.PreferenceManager.prototype.notifyAll = function() {
  for (var name in this.prefRecords_) {
    this.notifyChange_(name);
  }
};

/**
 * Notify the change observers for a given preference.
 *
 * @param {string} name The name of the preference that changed.
 */
lib.PreferenceManager.prototype.notifyChange_ = function(name) {
  var record = this.prefRecords_[name];
  if (!record)
    throw new Error('Unknown preference: ' + name);

  var currentValue = record.get();

  for (var i = 0; i < this.globalObservers_.length; i++)
    this.globalObservers_[i](name, currentValue);

  for (var i = 0; i < record.observers.length; i++) {
    record.observers[i](currentValue, name, this);
  }
};

/**
 * Create a new child PreferenceManager for the given child list.
 *
 * The optional hint parameter is an opaque prefix added to the auto-generated
 * unique id for this child.  Your child factory can parse out the prefix
 * and use it.
 *
 * @param {string} listName The child list to create the new instance from.
 * @param {string} opt_hint Optional hint to include in the child id.
 * @param {string} opt_id Optional id to override the generated id.
 */
lib.PreferenceManager.prototype.createChild = function(listName, opt_hint,
                                                       opt_id) {
  var ids = this.get(listName);
  var id;

  if (opt_id) {
    id = opt_id;
    if (ids.indexOf(id) != -1)
      throw new Error('Duplicate child: ' + listName + ': ' + id);

  } else {
    // Pick a random, unique 4-digit hex identifier for the new profile.
    while (!id || ids.indexOf(id) != -1) {
      id = lib.f.randomInt(1, 0xffff).toString(16);
      id = lib.f.zpad(id, 4);
      if (opt_hint)
        id = opt_hint + ':' + id;
    }
  }

  var childManager = this.childFactories_[listName](this, id);
  childManager.trace = this.trace;
  childManager.resetAll();

  this.childLists_[listName][id] = childManager;

  ids.push(id);
  this.set(listName, ids, undefined, !this.isImportingJson_);

  return childManager;
};

/**
 * Remove a child preferences instance.
 *
 * Removes a child preference manager and clears any preferences stored in it.
 *
 * @param {string} listName The name of the child list containing the child to
 *     remove.
 * @param {string} id The child ID.
 */
lib.PreferenceManager.prototype.removeChild = function(listName, id) {
  var prefs = this.getChild(listName, id);
  prefs.resetAll();

  var ids = this.get(listName);
  var i = ids.indexOf(id);
  if (i != -1) {
    ids.splice(i, 1);
    this.set(listName, ids, undefined, !this.isImportingJson_);
  }

  delete this.childLists_[listName][id];
};

/**
 * Return a child PreferenceManager instance for a given id.
 *
 * If the child list or child id is not known this will return the specified
 * default value or throw an exception if no default value is provided.
 *
 * @param {string} listName The child list to look in.
 * @param {string} id The child ID.
 * @param {*} opt_default The optional default value to return if the child
 *     is not found.
 */
lib.PreferenceManager.prototype.getChild = function(listName, id, opt_default) {
  if (!(listName in this.childLists_))
    throw new Error('Unknown child list: ' + listName);

  var childList = this.childLists_[listName];
  if (!(id in childList)) {
    if (typeof opt_default == 'undefined')
      throw new Error('Unknown "' + listName + '" child: ' + id);

    return opt_default;
  }

  return childList[id];
};

/**
 * Calculate the difference between two lists of child ids.
 *
 * Given two arrays of child ids, this function will return an object
 * with "added", "removed", and "common" properties.  Each property is
 * a map of child-id to `true`.  For example, given...
 *
 *    a = ['child-x', 'child-y']
 *    b = ['child-y']
 *
 *    diffChildLists(a, b) =>
 *      { added: { 'child-x': true }, removed: {}, common: { 'child-y': true } }
 *
 * The added/removed properties assume that `a` is the current list.
 *
 * @param {Array[string]} a The most recent list of child ids.
 * @param {Array[string]} b An older list of child ids.
 * @return {Object} An object with added/removed/common properties.
 */
lib.PreferenceManager.diffChildLists = function(a, b) {
  var rv = {
    added: {},
    removed: {},
    common: {},
  };

  for (var i = 0; i < a.length; i++) {
    if (b.indexOf(a[i]) != -1) {
      rv.common[a[i]] = true;
    } else {
      rv.added[a[i]] = true;
    }
  }

  for (var i = 0; i < b.length; i++) {
    if ((b[i] in rv.added) || (b[i] in rv.common))
      continue;

    rv.removed[b[i]] = true;
  }

  return rv;
};

/**
 * Synchronize a list of child PreferenceManagers instances with the current
 * list stored in prefs.
 *
 * This will instantiate any missing managers and read current preference values
 * from storage.  Any active managers that no longer appear in preferences will
 * be deleted.
 *
 * @param {string} listName The child list to synchronize.
 * @param {function()} opt_callback Optional function to invoke when the sync
 *     is complete.
 */
lib.PreferenceManager.prototype.syncChildList = function(
    listName, opt_callback) {

  var pendingChildren = 0;
  function onChildStorage() {
    if (--pendingChildren == 0 && opt_callback)
      opt_callback();
  }

  // The list of child ids that we *should* have a manager for.
  var currentIds = this.get(listName);

  // The known managers at the start of the sync.  Any manager still in this
  // list at the end should be discarded.
  var oldIds = Object.keys(this.childLists_[listName]);

  var rv = lib.PreferenceManager.diffChildLists(currentIds, oldIds);

  for (var i = 0; i < currentIds.length; i++) {
    var id = currentIds[i];

    var managerIndex = oldIds.indexOf(id);
    if (managerIndex >= 0)
      oldIds.splice(managerIndex, 1);

    if (!this.childLists_[listName][id]) {
      var childManager = this.childFactories_[listName](this, id);
      if (!childManager) {
        console.warn('Unable to restore child: ' + listName + ': ' + id);
        continue;
      }

      childManager.trace = this.trace;
      this.childLists_[listName][id] = childManager;
      pendingChildren++;
      childManager.readStorage(onChildStorage);
    }
  }

  for (var i = 0; i < oldIds.length; i++) {
    delete this.childLists_[listName][oldIds[i]];
  }

  if (!pendingChildren && opt_callback)
    setTimeout(opt_callback);
};

/**
 * Reset a preference to its default state.
 *
 * This will dispatch the onChange handler if the preference value actually
 * changes.
 *
 * @param {string} name The preference to reset.
 */
lib.PreferenceManager.prototype.reset = function(name) {
  var record = this.prefRecords_[name];
  if (!record)
    throw new Error('Unknown preference: ' + name);

  this.storage.removeItem(this.prefix + name);

  if (record.currentValue !== this.DEFAULT_VALUE) {
    record.currentValue = this.DEFAULT_VALUE;
    this.notifyChange_(name);
  }
};

/**
 * Reset all preferences back to their default state.
 */
lib.PreferenceManager.prototype.resetAll = function() {
  var changed = [];

  for (var listName in this.childLists_) {
    var childList = this.childLists_[listName];
    for (var id in childList) {
      childList[id].resetAll();
    }
  }

  for (var name in this.prefRecords_) {
    if (this.prefRecords_[name].currentValue !== this.DEFAULT_VALUE) {
      this.prefRecords_[name].currentValue = this.DEFAULT_VALUE;
      changed.push(name);
    }
  }

  var keys = Object.keys(this.prefRecords_).map(function(el) {
      return this.prefix + el;
  }.bind(this));

  this.storage.removeItems(keys);

  changed.forEach(this.notifyChange_.bind(this));
};

/**
 * Return true if two values should be considered not-equal.
 *
 * If both values are the same scalar type and compare equal this function
 * returns false (no difference), otherwise return true.
 *
 * This is used in places where we want to check if a preference has changed.
 * Rather than take the time to compare complex values we just consider them
 * to always be different.
 *
 * @param {*} a A value to compare.
 * @param {*} b A value to compare.
 */
lib.PreferenceManager.prototype.diff = function(a, b) {
  // If the types are different.
  if ((typeof a) !== (typeof b)) {
    return true;
  }

  // Or if the type is not a simple primitive one.
  if (!(/^(undefined|boolean|number|string)$/.test(typeof a))) {
    // Special case the null object.
    if (a === null && b === null) {
      return false;
    } else {
      return true;
    }
  }

  // Do a normal compare for primitive types.
  return a !== b;
};

/**
 * Change the default value of a preference.
 *
 * This is useful when subclassing preference managers.
 *
 * The function does not alter the current value of the preference, unless
 * it has the old default value.  When that happens, the change observers
 * will be notified.
 *
 * @param {string} name The name of the parameter to change.
 * @param {*} newValue The new default value for the preference.
 */
lib.PreferenceManager.prototype.changeDefault = function(name, newValue) {
  var record = this.prefRecords_[name];
  if (!record)
    throw new Error('Unknown preference: ' + name);

  if (!this.diff(record.defaultValue, newValue)) {
    // Default value hasn't changed.
    return;
  }

  if (record.currentValue !== this.DEFAULT_VALUE) {
    // This pref has a specific value, just change the default and we're done.
    record.defaultValue = newValue;
    return;
  }

  record.defaultValue = newValue;

  this.notifyChange_(name);
};

/**
 * Change the default value of multiple preferences.
 *
 * @param {Object} map A map of name -> value pairs specifying the new default
 *     values.
 */
lib.PreferenceManager.prototype.changeDefaults = function(map) {
  for (var key in map) {
    this.changeDefault(key, map[key]);
  }
};

/**
 * Set a preference to a specific value.
 *
 * This will dispatch the onChange handler if the preference value actually
 * changes.
 *
 * @param {string} name The preference to set.
 * @param {*} newValue The value to set.  Anything that can be represented in
 *     JSON is a valid value.
 * @param {function()=} onComplete Callback when the set call completes.
 * @param {boolean=} saveToStorage Whether to commit the change to the backing
 *     storage or only the in-memory record copy.
 */
lib.PreferenceManager.prototype.set = function(
    name, newValue, onComplete=undefined, saveToStorage=true) {
  var record = this.prefRecords_[name];
  if (!record)
    throw new Error('Unknown preference: ' + name);

  var oldValue = record.get();

  if (!this.diff(oldValue, newValue))
    return;

  if (this.diff(record.defaultValue, newValue)) {
    record.currentValue = newValue;
    if (saveToStorage)
      this.storage.setItem(this.prefix + name, newValue, onComplete);
  } else {
    record.currentValue = this.DEFAULT_VALUE;
    if (saveToStorage)
      this.storage.removeItem(this.prefix + name, onComplete);
  }

  // We need to manually send out the notification on this instance.  If we
  // The storage event won't fire a notification because we've already changed
  // the currentValue, so it won't see a difference.  If we delayed changing
  // currentValue until the storage event, a pref read immediately after a write
  // would return the previous value.
  //
  // The notification is in a timeout so clients don't accidentally depend on
  // a synchronous notification.
  setTimeout(this.notifyChange_.bind(this, name), 0);
};

/**
 * Get the value of a preference.
 *
 * @param {string} key The preference to get.
 */
lib.PreferenceManager.prototype.get = function(name) {
  var record = this.prefRecords_[name];
  if (!record)
    throw new Error('Unknown preference: ' + name);

  return record.get();
};

/**
 * Return all non-default preferences as a JSON object.
 *
 * This includes any nested preference managers as well.
 */
lib.PreferenceManager.prototype.exportAsJson = function() {
  var rv = {};

  for (var name in this.prefRecords_) {
    if (name in this.childLists_) {
      rv[name] = [];
      var childIds = this.get(name);
      for (var i = 0; i < childIds.length; i++) {
        var id = childIds[i];
        rv[name].push({id: id, json: this.getChild(name, id).exportAsJson()});
      }

    } else {
      var record = this.prefRecords_[name];
      if (record.currentValue != this.DEFAULT_VALUE)
        rv[name] = record.currentValue;
    }
  }

  return rv;
};

/**
 * Import a JSON blob of preferences previously generated with exportAsJson.
 *
 * This will create nested preference managers as well.
 */
lib.PreferenceManager.prototype.importFromJson = function(json, opt_onComplete) {
  this.isImportingJson_ = true;

  let pendingWrites = 0;
  const onWriteStorage = () => {
    if (--pendingWrites < 1) {
      if (opt_onComplete)
        opt_onComplete();

      // We've delayed updates to the child arrays, so flush them now.
      for (let name in json)
        if (name in this.childLists_)
          this.set(name, this.get(name));

      this.isImportingJson_ = false;
    }
  };

  for (var name in json) {
    if (name in this.childLists_) {
      var childList = json[name];
      for (var i = 0; i < childList.length; i++) {
        var id = childList[i].id;

        var childPrefManager = this.childLists_[name][id];
        if (!childPrefManager)
          childPrefManager = this.createChild(name, null, id);

        childPrefManager.importFromJson(childList[i].json, onWriteStorage);
        pendingWrites++;
      }

    } else {
      // The set is synchronous.
      this.set(name, json[name]);
    }
  }

  // If we didn't update any children, no async work has been queued, so make
  // the completion callback directly.
  if (pendingWrites == 0 && opt_onComplete)
    opt_onComplete();
};

/**
 * Called when one of the child list preferences changes.
 */
lib.PreferenceManager.prototype.onChildListChange_ = function(listName) {
  this.syncChildList(listName);
};

/**
 * Called when a key in the storage changes.
 */
lib.PreferenceManager.prototype.onStorageChange_ = function(map) {
  for (var key in map) {
    if (this.prefix) {
      if (key.lastIndexOf(this.prefix, 0) != 0)
        continue;
    }

    var name = key.substr(this.prefix.length);

    if (!(name in this.prefRecords_)) {
      // Sometimes we'll get notified about prefs that are no longer defined.
      continue;
    }

    var record = this.prefRecords_[name];

    var newValue = map[key].newValue;
    var currentValue = record.currentValue;
    if (currentValue === record.DEFAULT_VALUE)
      currentValue = (void 0);

    if (this.diff(currentValue, newValue)) {
      if (typeof newValue == 'undefined' || newValue === null) {
        record.currentValue = record.DEFAULT_VALUE;
      } else {
        record.currentValue = newValue;
      }

      this.notifyChange_(name);
    }
  }
};
// SOURCE FILE: libdot/js/lib_resource.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

/**
 * Storage for canned resources.
 *
 * These are usually non-JavaScript things that are collected during a build
 * step and converted into a series of 'lib.resource.add(...)' calls.  See
 * the "@resource" directive from libdot/bin/concat for the canonical use
 * case.
 *
 * This is global storage, so you should prefix your resource names to avoid
 * collisions.
 */
lib.resource = {
  resources_: {}
};

/**
 * Add a resource.
 *
 * @param {string} name A name for the resource.  You should prefix this to
 *   avoid collisions with resources from a shared library.
 * @param {string} type A mime type for the resource, or "raw" if not
 *   applicable.
 * @param {*} data The value of the resource.
 */
lib.resource.add = function(name, type, data) {
  lib.resource.resources_[name] = {
    type: type,
    name: name,
    data: data
  };
};

/**
 * Retrieve a resource record.
 *
 * The resource data is stored on the "data" property of the returned object.
 *
 * @param {string} name The name of the resource to get.
 * @param {*} opt_defaultValue The optional value to return if the resource is
 *   not defined.
 * @return {object} An object with "type", "name", and "data" properties.
 */
lib.resource.get = function(name, opt_defaultValue) {
  if (!(name in lib.resource.resources_)) {
    if (typeof opt_defaultValue == 'undefined')
      throw 'Unknown resource: ' + name;

    return opt_defaultValue;
  }

  return lib.resource.resources_[name];
};

/**
 * Retrieve resource data.
 *
 * @param {string} name The name of the resource to get.
 * @param {*} opt_defaultValue The optional value to return if the resource is
 *   not defined.
 * @return {*} The resource data.
 */
lib.resource.getData = function(name, opt_defaultValue) {
  if (!(name in lib.resource.resources_)) {
    if (typeof opt_defaultValue == 'undefined')
      throw 'Unknown resource: ' + name;

    return opt_defaultValue;
  }

  return lib.resource.resources_[name].data;
};

/**
 * Retrieve resource as a data: url.
 *
 * @param {string} name The name of the resource to get.
 * @param {*} opt_defaultValue The optional value to return if the resource is
 *   not defined.
 * @return {*} A data: url encoded version of the resource.
 */
lib.resource.getDataUrl = function(name, opt_defaultValue) {
  var resource = lib.resource.get(name, opt_defaultValue);
  return 'data:' + resource.type + ',' + resource.data;
};
// SOURCE FILE: libdot/js/lib_storage.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

/**
 * Namespace for implementations of persistent, possibly cloud-backed
 * storage.
 */
lib.Storage = new Object();
// SOURCE FILE: libdot/js/lib_storage_chrome.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

/**
 * chrome.storage based class with an async interface that is interchangeable
 * with other lib.Storage.* implementations.
 */
lib.Storage.Chrome = function(storage) {
  this.storage_ = storage;
  this.observers_ = [];

  chrome.storage.onChanged.addListener(this.onChanged_.bind(this));
};

/**
 * Called by the storage implementation when the storage is modified.
 */
lib.Storage.Chrome.prototype.onChanged_ = function(changes, areaname) {
  if (chrome.storage[areaname] != this.storage_)
    return;

  for (var i = 0; i < this.observers_.length; i++) {
    this.observers_[i](changes);
  }
};

/**
 * Register a function to observe storage changes.
 *
 * @param {function(map)} callback The function to invoke when the storage
 *     changes.
 */
lib.Storage.Chrome.prototype.addObserver = function(callback) {
  this.observers_.push(callback);
};

/**
 * Unregister a change observer.
 *
 * @param {function} observer A previously registered callback.
 */
lib.Storage.Chrome.prototype.removeObserver = function(callback) {
  var i = this.observers_.indexOf(callback);
  if (i != -1)
    this.observers_.splice(i, 1);
};

/**
 * Delete everything in this storage.
 *
 * @param {function(map)} callback The function to invoke when the delete
 *     has completed.
 */
lib.Storage.Chrome.prototype.clear = function(opt_callback) {
  this.storage_.clear();

  if (opt_callback)
    setTimeout(opt_callback, 0);
};

/**
 * Return the current value of a storage item.
 *
 * @param {string} key The key to look up.
 * @param {function(value) callback The function to invoke when the value has
 *     been retrieved.
 */
lib.Storage.Chrome.prototype.getItem = function(key, callback) {
  this.storage_.get(key, callback);
};
/**
 * Fetch the values of multiple storage items.
 *
 * @param {Array} keys The keys to look up.
 * @param {function(map) callback The function to invoke when the values have
 *     been retrieved.
 */

lib.Storage.Chrome.prototype.getItems = function(keys, callback) {
  this.storage_.get(keys, callback);
};

/**
 * Set a value in storage.
 *
 * @param {string} key The key for the value to be stored.
 * @param {*} value The value to be stored.  Anything that can be serialized
 *     with JSON is acceptable.
 * @param {function()} opt_callback Optional function to invoke when the
 *     set is complete.  You don't have to wait for the set to complete in order
 *     to read the value, since the local cache is updated synchronously.
 */
lib.Storage.Chrome.prototype.setItem = function(key, value, opt_callback) {
  const onComplete = () => {
    const err = lib.f.lastError();
    if (err) {
      // Doesn't seem to be any better way of handling this.
      // https://crbug.com/764759
      if (err.indexOf('MAX_WRITE_OPERATIONS')) {
        console.warn(`Will retry save of ${key} after exceeding quota: ${err}`);
        setTimeout(() => this.setItem(key, value, onComplete), 1000);
        return;
      } else {
        console.error(`Unknown runtime error: ${err}`);
      }
    }

    if (opt_callback)
      opt_callback();
  };

  var obj = {};
  obj[key] = value;
  this.storage_.set(obj, onComplete);
};

/**
 * Set multiple values in storage.
 *
 * @param {Object} map A map of key/values to set in storage.
 * @param {function()} opt_callback Optional function to invoke when the
 *     set is complete.  You don't have to wait for the set to complete in order
 *     to read the value, since the local cache is updated synchronously.
 */
lib.Storage.Chrome.prototype.setItems = function(obj, opt_callback) {
  this.storage_.set(obj, opt_callback);
};

/**
 * Remove an item from storage.
 *
 * @param {string} key The key to be removed.
 * @param {function()} opt_callback Optional function to invoke when the
 *     remove is complete.  You don't have to wait for the set to complete in
 *     order to read the value, since the local cache is updated synchronously.
 */
lib.Storage.Chrome.prototype.removeItem = function(key, opt_callback) {
  this.storage_.remove(key, opt_callback);
};

/**
 * Remove multiple items from storage.
 *
 * @param {Array} keys The keys to be removed.
 * @param {function()} opt_callback Optional function to invoke when the
 *     remove is complete.  You don't have to wait for the set to complete in
 *     order to read the value, since the local cache is updated synchronously.
 */
lib.Storage.Chrome.prototype.removeItems = function(keys, opt_callback) {
  this.storage_.remove(keys, opt_callback);
};
// SOURCE FILE: libdot/js/lib_storage_local.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

/**
 * window.localStorage based class with an async interface that is
 * interchangeable with other lib.Storage.* implementations.
 */
lib.Storage.Local = function() {
  this.observers_ = [];
  this.storage_ = window.localStorage;
  window.addEventListener('storage', this.onStorage_.bind(this));
};

/**
 * Called by the storage implementation when the storage is modified.
 */
lib.Storage.Local.prototype.onStorage_ = function(e) {
  if (e.storageArea != this.storage_)
    return;

  // JS throws an exception if JSON.parse is given an empty string. So here we
  // only parse if the value is truthy. This mean the empty string, undefined
  // and null will not be parsed.
  var prevValue = e.oldValue ? JSON.parse(e.oldValue) : e.oldValue;
  var curValue = e.newValue ? JSON.parse(e.newValue) : e.newValue;
  var o = {};
  o[e.key] = {
    oldValue: prevValue,
    newValue: curValue
  };

  for (var i = 0; i < this.observers_.length; i++) {
    this.observers_[i](o);
  }
};

/**
 * Register a function to observe storage changes.
 *
 * @param {function(map)} callback The function to invoke when the storage
 *     changes.
 */
lib.Storage.Local.prototype.addObserver = function(callback) {
  this.observers_.push(callback);
};

/**
 * Unregister a change observer.
 *
 * @param {function} observer A previously registered callback.
 */
lib.Storage.Local.prototype.removeObserver = function(callback) {
  var i = this.observers_.indexOf(callback);
  if (i != -1)
    this.observers_.splice(i, 1);
};

/**
 * Delete everything in this storage.
 *
 * @param {function(map)} callback The function to invoke when the delete
 *     has completed.
 */
lib.Storage.Local.prototype.clear = function(opt_callback) {
  this.storage_.clear();

  if (opt_callback)
    setTimeout(opt_callback, 0);
};

/**
 * Return the current value of a storage item.
 *
 * @param {string} key The key to look up.
 * @param {function(value) callback The function to invoke when the value has
 *     been retrieved.
 */
lib.Storage.Local.prototype.getItem = function(key, callback) {
  var value = this.storage_.getItem(key);

  if (typeof value == 'string') {
    try {
      value = JSON.parse(value);
    } catch (e) {
      // If we can't parse the value, just return it unparsed.
    }
  }

  setTimeout(callback.bind(null, value), 0);
};

/**
 * Fetch the values of multiple storage items.
 *
 * @param {Array} keys The keys to look up.
 * @param {function(map) callback The function to invoke when the values have
 *     been retrieved.
 */
lib.Storage.Local.prototype.getItems = function(keys, callback) {
  var rv = {};

  for (var i = keys.length - 1; i >= 0; i--) {
    var key = keys[i];
    var value = this.storage_.getItem(key);
    if (typeof value == 'string') {
      try {
        rv[key] = JSON.parse(value);
      } catch (e) {
        // If we can't parse the value, just return it unparsed.
        rv[key] = value;
      }
    } else {
      keys.splice(i, 1);
    }
  }

  setTimeout(callback.bind(null, rv), 0);
};

/**
 * Set a value in storage.
 *
 * @param {string} key The key for the value to be stored.
 * @param {*} value The value to be stored.  Anything that can be serialized
 *     with JSON is acceptable.
 * @param {function()} opt_callback Optional function to invoke when the
 *     set is complete.  You don't have to wait for the set to complete in order
 *     to read the value, since the local cache is updated synchronously.
 */
lib.Storage.Local.prototype.setItem = function(key, value, opt_callback) {
  this.storage_.setItem(key, JSON.stringify(value));

  if (opt_callback)
  setTimeout(opt_callback, 0);
};

/**
 * Set multiple values in storage.
 *
 * @param {Object} map A map of key/values to set in storage.
 * @param {function()} opt_callback Optional function to invoke when the
 *     set is complete.  You don't have to wait for the set to complete in order
 *     to read the value, since the local cache is updated synchronously.
 */
lib.Storage.Local.prototype.setItems = function(obj, opt_callback) {
  for (var key in obj) {
    this.storage_.setItem(key, JSON.stringify(obj[key]));
  }

  if (opt_callback)
  setTimeout(opt_callback, 0);
};

/**
 * Remove an item from storage.
 *
 * @param {string} key The key to be removed.
 * @param {function()} opt_callback Optional function to invoke when the
 *     remove is complete.  You don't have to wait for the set to complete in
 *     order to read the value, since the local cache is updated synchronously.
 */
lib.Storage.Local.prototype.removeItem = function(key, opt_callback) {
  this.storage_.removeItem(key);

  if (opt_callback)
  setTimeout(opt_callback, 0);
};

/**
 * Remove multiple items from storage.
 *
 * @param {Array} keys The keys to be removed.
 * @param {function()} opt_callback Optional function to invoke when the
 *     remove is complete.  You don't have to wait for the set to complete in
 *     order to read the value, since the local cache is updated synchronously.
 */
lib.Storage.Local.prototype.removeItems = function(ary, opt_callback) {
  for (var i = 0; i < ary.length; i++) {
    this.storage_.removeItem(ary[i]);
  }

  if (opt_callback)
  setTimeout(opt_callback, 0);
};
// SOURCE FILE: libdot/js/lib_storage_memory.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

/**
 * In-memory storage class with an async interface that is interchangeable with
 * other lib.Storage.* implementations.
 */
lib.Storage.Memory = function() {
  this.observers_ = [];
  this.storage_ = {};
};

/**
 * Register a function to observe storage changes.
 *
 * @param {function(map)} callback The function to invoke when the storage
 *     changes.
 */
lib.Storage.Memory.prototype.addObserver = function(callback) {
  this.observers_.push(callback);
};

/**
 * Unregister a change observer.
 *
 * @param {function} observer A previously registered callback.
 */
lib.Storage.Memory.prototype.removeObserver = function(callback) {
  var i = this.observers_.indexOf(callback);
  if (i != -1)
    this.observers_.splice(i, 1);
};

/**
 * Delete everything in this storage.
 *
 * @param {function(map)} callback The function to invoke when the delete
 *     has completed.
 */
lib.Storage.Memory.prototype.clear = function(opt_callback) {
  var e = {};
  for (var key in this.storage_) {
    e[key] = {oldValue: this.storage_[key], newValue: (void 0)};
  }

  this.storage_ = {};

  setTimeout(function() {
    for (var i = 0; i < this.observers_.length; i++) {
      this.observers_[i](e);
    }
  }.bind(this), 0);

  if (opt_callback)
    setTimeout(opt_callback, 0);
};

/**
 * Return the current value of a storage item.
 *
 * @param {string} key The key to look up.
 * @param {function(value) callback The function to invoke when the value has
 *     been retrieved.
 */
lib.Storage.Memory.prototype.getItem = function(key, callback) {
  var value = this.storage_[key];

  if (typeof value == 'string') {
    try {
      value = JSON.parse(value);
    } catch (e) {
      // If we can't parse the value, just return it unparsed.
    }
  }

  setTimeout(callback.bind(null, value), 0);
};

/**
 * Fetch the values of multiple storage items.
 *
 * @param {Array} keys The keys to look up.
 * @param {function(map) callback The function to invoke when the values have
 *     been retrieved.
 */
lib.Storage.Memory.prototype.getItems = function(keys, callback) {
  var rv = {};

  for (var i = keys.length - 1; i >= 0; i--) {
    var key = keys[i];
    var value = this.storage_[key];
    if (typeof value == 'string') {
      try {
        rv[key] = JSON.parse(value);
      } catch (e) {
        // If we can't parse the value, just return it unparsed.
        rv[key] = value;
      }
    } else {
      keys.splice(i, 1);
    }
  }

  setTimeout(callback.bind(null, rv), 0);
};

/**
 * Set a value in storage.
 *
 * @param {string} key The key for the value to be stored.
 * @param {*} value The value to be stored.  Anything that can be serialized
 *     with JSON is acceptable.
 * @param {function()} opt_callback Optional function to invoke when the
 *     set is complete.  You don't have to wait for the set to complete in order
 *     to read the value, since the local cache is updated synchronously.
 */
lib.Storage.Memory.prototype.setItem = function(key, value, opt_callback) {
  var oldValue = this.storage_[key];
  this.storage_[key] = JSON.stringify(value);

  var e = {};
  e[key] = {oldValue: oldValue, newValue: value};

  setTimeout(function() {
    for (var i = 0; i < this.observers_.length; i++) {
      this.observers_[i](e);
    }
  }.bind(this), 0);

  if (opt_callback)
  setTimeout(opt_callback, 0);
};

/**
 * Set multiple values in storage.
 *
 * @param {Object} map A map of key/values to set in storage.
 * @param {function()} opt_callback Optional function to invoke when the
 *     set is complete.  You don't have to wait for the set to complete in order
 *     to read the value, since the local cache is updated synchronously.
 */
lib.Storage.Memory.prototype.setItems = function(obj, opt_callback) {
  var e = {};

  for (var key in obj) {
    e[key] = {oldValue: this.storage_[key], newValue: obj[key]};
    this.storage_[key] = JSON.stringify(obj[key]);
  }

  setTimeout(function() {
    for (var i = 0; i < this.observers_.length; i++) {
      this.observers_[i](e);
    }
  }.bind(this));

  if (opt_callback)
  setTimeout(opt_callback, 0);
};

/**
 * Remove an item from storage.
 *
 * @param {string} key The key to be removed.
 * @param {function()} opt_callback Optional function to invoke when the
 *     remove is complete.  You don't have to wait for the set to complete in
 *     order to read the value, since the local cache is updated synchronously.
 */
lib.Storage.Memory.prototype.removeItem = function(key, opt_callback) {
  delete this.storage_[key];

  if (opt_callback)
  setTimeout(opt_callback, 0);
};

/**
 * Remove multiple items from storage.
 *
 * @param {Array} keys The keys to be removed.
 * @param {function()} opt_callback Optional function to invoke when the
 *     remove is complete.  You don't have to wait for the set to complete in
 *     order to read the value, since the local cache is updated synchronously.
 */
lib.Storage.Memory.prototype.removeItems = function(ary, opt_callback) {
  for (var i = 0; i < ary.length; i++) {
    delete this.storage_[ary[i]];
  }

  if (opt_callback)
  setTimeout(opt_callback, 0);
};
// SOURCE FILE: libdot/js/lib_utf8.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// TODO(davidben): When the string encoding API is implemented,
// replace this with the native in-browser implementation.
//
// https://wiki.whatwg.org/wiki/StringEncoding
// https://encoding.spec.whatwg.org/

/**
 * A stateful UTF-8 decoder.
 */
lib.UTF8Decoder = function() {
  // The number of bytes left in the current sequence.
  this.bytesLeft = 0;
  // The in-progress code point being decoded, if bytesLeft > 0.
  this.codePoint = 0;
  // The lower bound on the final code point, if bytesLeft > 0.
  this.lowerBound = 0;
};

/**
 * Decodes a some UTF-8 data, taking into account state from previous
 * data streamed through the encoder.
 *
 * @param {String} str data to decode, represented as a JavaScript
 *     String with each code unit representing a byte between 0x00 to
 *     0xFF.
 * @return {String} The data decoded into a JavaScript UTF-16 string.
 */
lib.UTF8Decoder.prototype.decode = function(str) {
  var ret = '';
  for (var i = 0; i < str.length; i++) {
    var c = str.charCodeAt(i);
    if (this.bytesLeft == 0) {
      if (c <= 0x7F) {
        ret += str.charAt(i);
      } else if (0xC0 <= c && c <= 0xDF) {
        this.codePoint = c - 0xC0;
        this.bytesLeft = 1;
        this.lowerBound = 0x80;
      } else if (0xE0 <= c && c <= 0xEF) {
        this.codePoint = c - 0xE0;
        this.bytesLeft = 2;
        this.lowerBound = 0x800;
      } else if (0xF0 <= c && c <= 0xF7) {
        this.codePoint = c - 0xF0;
        this.bytesLeft = 3;
        this.lowerBound = 0x10000;
      } else if (0xF8 <= c && c <= 0xFB) {
        this.codePoint = c - 0xF8;
        this.bytesLeft = 4;
        this.lowerBound = 0x200000;
      } else if (0xFC <= c && c <= 0xFD) {
        this.codePoint = c - 0xFC;
        this.bytesLeft = 5;
        this.lowerBound = 0x4000000;
      } else {
        ret += '\ufffd';
      }
    } else {
      if (0x80 <= c && c <= 0xBF) {
        this.bytesLeft--;
        this.codePoint = (this.codePoint << 6) + (c - 0x80);
        if (this.bytesLeft == 0) {
          // Got a full sequence. Check if it's within bounds and
          // filter out surrogate pairs.
          var codePoint = this.codePoint;
          if (codePoint < this.lowerBound
              || (0xD800 <= codePoint && codePoint <= 0xDFFF)
              || codePoint > 0x10FFFF) {
            ret += '\ufffd';
          } else {
            // Encode as UTF-16 in the output.
            if (codePoint < 0x10000) {
              ret += String.fromCharCode(codePoint);
            } else {
              // Surrogate pair.
              codePoint -= 0x10000;
              ret += String.fromCharCode(
                0xD800 + ((codePoint >>> 10) & 0x3FF),
                0xDC00 + (codePoint & 0x3FF));
            }
          }
        }
      } else {
        // Too few bytes in multi-byte sequence. Rewind stream so we
        // don't lose the next byte.
        ret += '\ufffd';
        this.bytesLeft = 0;
        i--;
      }
    }
  }
  return ret;
};

/**
 * Decodes UTF-8 data. This is a convenience function for when all the
 * data is already known.
 *
 * @param {String} str data to decode, represented as a JavaScript
 *     String with each code unit representing a byte between 0x00 to
 *     0xFF.
 * @return {String} The data decoded into a JavaScript UTF-16 string.
 */
lib.decodeUTF8 = function(utf8) {
  return (new lib.UTF8Decoder()).decode(utf8);
};

/**
 * Encodes a UTF-16 string into UTF-8.
 *
 * TODO(davidben): Do we need a stateful version of this that can
 * handle a surrogate pair split in two calls? What happens if a
 * keypress event would have contained a character outside the BMP?
 *
 * @param {String} str The string to encode.
 * @return {String} The string encoded as UTF-8, as a JavaScript
 *     string with bytes represented as code units from 0x00 to 0xFF.
 */
lib.encodeUTF8 = function(str) {
  var ret = '';
  for (var i = 0; i < str.length; i++) {
    // Get a unicode code point out of str.
    var c = str.charCodeAt(i);
    if (0xDC00 <= c && c <= 0xDFFF) {
      c = 0xFFFD;
    } else if (0xD800 <= c && c <= 0xDBFF) {
      if (i+1 < str.length) {
        var d = str.charCodeAt(i+1);
        if (0xDC00 <= d && d <= 0xDFFF) {
          // Swallow a surrogate pair.
          c = 0x10000 + ((c & 0x3FF) << 10) + (d & 0x3FF);
          i++;
        } else {
          c = 0xFFFD;
        }
      } else {
        c = 0xFFFD;
      }
    }

    // Encode c in UTF-8.
    var bytesLeft;
    if (c <= 0x7F) {
      ret += str.charAt(i);
      continue;
    } else if (c <= 0x7FF) {
      ret += String.fromCharCode(0xC0 | (c >>> 6));
      bytesLeft = 1;
    } else if (c <= 0xFFFF) {
      ret += String.fromCharCode(0xE0 | (c >>> 12));
      bytesLeft = 2;
    } else /* if (c <= 0x10FFFF) */ {
      ret += String.fromCharCode(0xF0 | (c >>> 18));
      bytesLeft = 3;
    }

    while (bytesLeft > 0) {
      bytesLeft--;
      ret += String.fromCharCode(0x80 | ((c >>> (6 * bytesLeft)) & 0x3F));
    }
  }
  return ret;
};
// SOURCE FILE: libdot/third_party/wcwidth/lib_wc.js
// Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
// Use of lib.wc source code is governed by a BSD-style license that can be
// found in the LICENSE file.

/**
 * This JavaScript library is ported from the wcwidth.js module of node.js.
 * The original implementation can be found at:
 * https://npmjs.org/package/wcwidth.js
 */

/**
 * JavaScript porting of Markus Kuhn's wcwidth() implementation
 *
 * The following explanation comes from the original C implementation:
 *
 * This is an implementation of wcwidth() and wcswidth() (defined in
 * IEEE Std 1002.1-2001) for Unicode.
 *
 * http://www.opengroup.org/onlinepubs/007904975/functions/wcwidth.html
 * http://www.opengroup.org/onlinepubs/007904975/functions/wcswidth.html
 *
 * In fixed-width output devices, Latin characters all occupy a single
 * "cell" position of equal width, whereas ideographic CJK characters
 * occupy two such cells. Interoperability between terminal-line
 * applications and (teletype-style) character terminals using the
 * UTF-8 encoding requires agreement on which character should advance
 * the cursor by how many cell positions. No established formal
 * standards exist at present on which Unicode character shall occupy
 * how many cell positions on character terminals. These routines are
 * a first attempt of defining such behavior based on simple rules
 * applied to data provided by the Unicode Consortium.
 *
 * For some graphical characters, the Unicode standard explicitly
 * defines a character-cell width via the definition of the East Asian
 * FullWidth (F), Wide (W), Half-width (H), and Narrow (Na) classes.
 * In all these cases, there is no ambiguity about which width a
 * terminal shall use. For characters in the East Asian Ambiguous (A)
 * class, the width choice depends purely on a preference of backward
 * compatibility with either historic CJK or Western practice.
 * Choosing single-width for these characters is easy to justify as
 * the appropriate long-term solution, as the CJK practice of
 * displaying these characters as double-width comes from historic
 * implementation simplicity (8-bit encoded characters were displayed
 * single-width and 16-bit ones double-width, even for Greek,
 * Cyrillic, etc.) and not any typographic considerations.
 *
 * Much less clear is the choice of width for the Not East Asian
 * (Neutral) class. Existing practice does not dictate a width for any
 * of these characters. It would nevertheless make sense
 * typographically to allocate two character cells to characters such
 * as for instance EM SPACE or VOLUME INTEGRAL, which cannot be
 * represented adequately with a single-width glyph. The following
 * routines at present merely assign a single-cell width to all
 * neutral characters, in the interest of simplicity. This is not
 * entirely satisfactory and should be reconsidered before
 * establishing a formal standard in lib.wc area. At the moment, the
 * decision which Not East Asian (Neutral) characters should be
 * represented by double-width glyphs cannot yet be answered by
 * applying a simple rule from the Unicode database content. Setting
 * up a proper standard for the behavior of UTF-8 character terminals
 * will require a careful analysis not only of each Unicode character,
 * but also of each presentation form, something the author of these
 * routines has avoided to do so far.
 *
 * http://www.unicode.org/unicode/reports/tr11/
 *
 * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
 *
 * Permission to use, copy, modify, and distribute lib.wc software
 * for any purpose and without fee is hereby granted. The author
 * disclaims all warranties with regard to lib.wc software.
 *
 * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
 */

/**
 * The following function defines the column width of an ISO 10646 character
 * as follows:
 *
 *  - The null character (U+0000) has a column width of 0.
 *  - Other C0/C1 control characters and DEL will lead to a return value of -1.
 *  - Non-spacing and enclosing combining characters (general category code Mn
 *    or Me in the Unicode database) have a column width of 0.
 *  - SOFT HYPHEN (U+00AD) has a column width of 1.
 *  - Other format characters (general category code Cf in the Unicode database)
 *    and ZERO WIDTH SPACE (U+200B) have a column width of 0.
 *  - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF) have a
 *    column width of 0.
 *  - Spacing characters in the East Asian Wide (W) or East Asian Full-width (F)
 *    category as defined in Unicode Technical Report #11 have a column width of
 *    2.
 *  - East Asian Ambiguous characters are taken into account if
 *    regardCjkAmbiguous flag is enabled. They have a column width of 2.
 *  - All remaining characters (including all printable ISO 8859-1 and WGL4
 *    characters, Unicode control characters, etc.) have a column width of 1.
 *
 * This implementation assumes that characters are encoded in ISO 10646.
 */

lib.wc = {};

// Width of a nul character.
lib.wc.nulWidth = 0;

// Width of a control character.
lib.wc.controlWidth = 0;

// Flag whether to consider East Asian Ambiguous characters.
lib.wc.regardCjkAmbiguous = false;

// Width of an East Asian Ambiguous character.
lib.wc.cjkAmbiguousWidth = 2;

// Sorted list of non-overlapping intervals of non-spacing characters
// generated by the `./ranges.py` helper.
lib.wc.combining = [
    [0x00ad, 0x00ad], [0x0300, 0x036f], [0x0483, 0x0489],
    [0x0591, 0x05bd], [0x05bf, 0x05bf], [0x05c1, 0x05c2],
    [0x05c4, 0x05c5], [0x05c7, 0x05c7], [0x0610, 0x061a],
    [0x061c, 0x061c], [0x064b, 0x065f], [0x0670, 0x0670],
    [0x06d6, 0x06dc], [0x06df, 0x06e4], [0x06e7, 0x06e8],
    [0x06ea, 0x06ed], [0x0711, 0x0711], [0x0730, 0x074a],
    [0x07a6, 0x07b0], [0x07eb, 0x07f3], [0x07fd, 0x07fd],
    [0x0816, 0x0819], [0x081b, 0x0823], [0x0825, 0x0827],
    [0x0829, 0x082d], [0x0859, 0x085b], [0x08d3, 0x08e1],
    [0x08e3, 0x0902], [0x093a, 0x093a], [0x093c, 0x093c],
    [0x0941, 0x0948], [0x094d, 0x094d], [0x0951, 0x0957],
    [0x0962, 0x0963], [0x0981, 0x0981], [0x09bc, 0x09bc],
    [0x09c1, 0x09c4], [0x09cd, 0x09cd], [0x09e2, 0x09e3],
    [0x09fe, 0x09fe], [0x0a01, 0x0a02], [0x0a3c, 0x0a3c],
    [0x0a41, 0x0a42], [0x0a47, 0x0a48], [0x0a4b, 0x0a4d],
    [0x0a51, 0x0a51], [0x0a70, 0x0a71], [0x0a75, 0x0a75],
    [0x0a81, 0x0a82], [0x0abc, 0x0abc], [0x0ac1, 0x0ac5],
    [0x0ac7, 0x0ac8], [0x0acd, 0x0acd], [0x0ae2, 0x0ae3],
    [0x0afa, 0x0aff], [0x0b01, 0x0b01], [0x0b3c, 0x0b3c],
    [0x0b3f, 0x0b3f], [0x0b41, 0x0b44], [0x0b4d, 0x0b4d],
    [0x0b56, 0x0b56], [0x0b62, 0x0b63], [0x0b82, 0x0b82],
    [0x0bc0, 0x0bc0], [0x0bcd, 0x0bcd], [0x0c00, 0x0c00],
    [0x0c04, 0x0c04], [0x0c3e, 0x0c40], [0x0c46, 0x0c48],
    [0x0c4a, 0x0c4d], [0x0c55, 0x0c56], [0x0c62, 0x0c63],
    [0x0c81, 0x0c81], [0x0cbc, 0x0cbc], [0x0cbf, 0x0cbf],
    [0x0cc6, 0x0cc6], [0x0ccc, 0x0ccd], [0x0ce2, 0x0ce3],
    [0x0d00, 0x0d01], [0x0d3b, 0x0d3c], [0x0d41, 0x0d44],
    [0x0d4d, 0x0d4d], [0x0d62, 0x0d63], [0x0dca, 0x0dca],
    [0x0dd2, 0x0dd4], [0x0dd6, 0x0dd6], [0x0e31, 0x0e31],
    [0x0e34, 0x0e3a], [0x0e47, 0x0e4e], [0x0eb1, 0x0eb1],
    [0x0eb4, 0x0eb9], [0x0ebb, 0x0ebc], [0x0ec8, 0x0ecd],
    [0x0f18, 0x0f19], [0x0f35, 0x0f35], [0x0f37, 0x0f37],
    [0x0f39, 0x0f39], [0x0f71, 0x0f7e], [0x0f80, 0x0f84],
    [0x0f86, 0x0f87], [0x0f8d, 0x0f97], [0x0f99, 0x0fbc],
    [0x0fc6, 0x0fc6], [0x102d, 0x1030], [0x1032, 0x1037],
    [0x1039, 0x103a], [0x103d, 0x103e], [0x1058, 0x1059],
    [0x105e, 0x1060], [0x1071, 0x1074], [0x1082, 0x1082],
    [0x1085, 0x1086], [0x108d, 0x108d], [0x109d, 0x109d],
    [0x1160, 0x11ff], [0x135d, 0x135f], [0x1712, 0x1714],
    [0x1732, 0x1734], [0x1752, 0x1753], [0x1772, 0x1773],
    [0x17b4, 0x17b5], [0x17b7, 0x17bd], [0x17c6, 0x17c6],
    [0x17c9, 0x17d3], [0x17dd, 0x17dd], [0x180b, 0x180e],
    [0x1885, 0x1886], [0x18a9, 0x18a9], [0x1920, 0x1922],
    [0x1927, 0x1928], [0x1932, 0x1932], [0x1939, 0x193b],
    [0x1a17, 0x1a18], [0x1a1b, 0x1a1b], [0x1a56, 0x1a56],
    [0x1a58, 0x1a5e], [0x1a60, 0x1a60], [0x1a62, 0x1a62],
    [0x1a65, 0x1a6c], [0x1a73, 0x1a7c], [0x1a7f, 0x1a7f],
    [0x1ab0, 0x1abe], [0x1b00, 0x1b03], [0x1b34, 0x1b34],
    [0x1b36, 0x1b3a], [0x1b3c, 0x1b3c], [0x1b42, 0x1b42],
    [0x1b6b, 0x1b73], [0x1b80, 0x1b81], [0x1ba2, 0x1ba5],
    [0x1ba8, 0x1ba9], [0x1bab, 0x1bad], [0x1be6, 0x1be6],
    [0x1be8, 0x1be9], [0x1bed, 0x1bed], [0x1bef, 0x1bf1],
    [0x1c2c, 0x1c33], [0x1c36, 0x1c37], [0x1cd0, 0x1cd2],
    [0x1cd4, 0x1ce0], [0x1ce2, 0x1ce8], [0x1ced, 0x1ced],
    [0x1cf4, 0x1cf4], [0x1cf8, 0x1cf9], [0x1dc0, 0x1df9],
    [0x1dfb, 0x1dff], [0x200b, 0x200f], [0x202a, 0x202e],
    [0x2060, 0x2064], [0x2066, 0x206f], [0x20d0, 0x20f0],
    [0x2cef, 0x2cf1], [0x2d7f, 0x2d7f], [0x2de0, 0x2dff],
    [0x302a, 0x302d], [0x3099, 0x309a], [0xa66f, 0xa672],
    [0xa674, 0xa67d], [0xa69e, 0xa69f], [0xa6f0, 0xa6f1],
    [0xa802, 0xa802], [0xa806, 0xa806], [0xa80b, 0xa80b],
    [0xa825, 0xa826], [0xa8c4, 0xa8c5], [0xa8e0, 0xa8f1],
    [0xa8ff, 0xa8ff], [0xa926, 0xa92d], [0xa947, 0xa951],
    [0xa980, 0xa982], [0xa9b3, 0xa9b3], [0xa9b6, 0xa9b9],
    [0xa9bc, 0xa9bc], [0xa9e5, 0xa9e5], [0xaa29, 0xaa2e],
    [0xaa31, 0xaa32], [0xaa35, 0xaa36], [0xaa43, 0xaa43],
    [0xaa4c, 0xaa4c], [0xaa7c, 0xaa7c], [0xaab0, 0xaab0],
    [0xaab2, 0xaab4], [0xaab7, 0xaab8], [0xaabe, 0xaabf],
    [0xaac1, 0xaac1], [0xaaec, 0xaaed], [0xaaf6, 0xaaf6],
    [0xabe5, 0xabe5], [0xabe8, 0xabe8], [0xabed, 0xabed],
    [0xfb1e, 0xfb1e], [0xfe00, 0xfe0f], [0xfe20, 0xfe2f],
    [0xfeff, 0xfeff], [0xfff9, 0xfffb], [0x101fd, 0x101fd],
    [0x102e0, 0x102e0], [0x10376, 0x1037a], [0x10a01, 0x10a03],
    [0x10a05, 0x10a06], [0x10a0c, 0x10a0f], [0x10a38, 0x10a3a],
    [0x10a3f, 0x10a3f], [0x10ae5, 0x10ae6], [0x10d24, 0x10d27],
    [0x10f46, 0x10f50], [0x11001, 0x11001], [0x11038, 0x11046],
    [0x1107f, 0x11081], [0x110b3, 0x110b6], [0x110b9, 0x110ba],
    [0x11100, 0x11102], [0x11127, 0x1112b], [0x1112d, 0x11134],
    [0x11173, 0x11173], [0x11180, 0x11181], [0x111b6, 0x111be],
    [0x111c9, 0x111cc], [0x1122f, 0x11231], [0x11234, 0x11234],
    [0x11236, 0x11237], [0x1123e, 0x1123e], [0x112df, 0x112df],
    [0x112e3, 0x112ea], [0x11300, 0x11301], [0x1133b, 0x1133c],
    [0x11340, 0x11340], [0x11366, 0x1136c], [0x11370, 0x11374],
    [0x11438, 0x1143f], [0x11442, 0x11444], [0x11446, 0x11446],
    [0x1145e, 0x1145e], [0x114b3, 0x114b8], [0x114ba, 0x114ba],
    [0x114bf, 0x114c0], [0x114c2, 0x114c3], [0x115b2, 0x115b5],
    [0x115bc, 0x115bd], [0x115bf, 0x115c0], [0x115dc, 0x115dd],
    [0x11633, 0x1163a], [0x1163d, 0x1163d], [0x1163f, 0x11640],
    [0x116ab, 0x116ab], [0x116ad, 0x116ad], [0x116b0, 0x116b5],
    [0x116b7, 0x116b7], [0x1171d, 0x1171f], [0x11722, 0x11725],
    [0x11727, 0x1172b], [0x1182f, 0x11837], [0x11839, 0x1183a],
    [0x11a01, 0x11a0a], [0x11a33, 0x11a38], [0x11a3b, 0x11a3e],
    [0x11a47, 0x11a47], [0x11a51, 0x11a56], [0x11a59, 0x11a5b],
    [0x11a8a, 0x11a96], [0x11a98, 0x11a99], [0x11c30, 0x11c36],
    [0x11c38, 0x11c3d], [0x11c3f, 0x11c3f], [0x11c92, 0x11ca7],
    [0x11caa, 0x11cb0], [0x11cb2, 0x11cb3], [0x11cb5, 0x11cb6],
    [0x11d31, 0x11d36], [0x11d3a, 0x11d3a], [0x11d3c, 0x11d3d],
    [0x11d3f, 0x11d45], [0x11d47, 0x11d47], [0x11d90, 0x11d91],
    [0x11d95, 0x11d95], [0x11d97, 0x11d97], [0x11ef3, 0x11ef4],
    [0x16af0, 0x16af4], [0x16b30, 0x16b36], [0x16f8f, 0x16f92],
    [0x1bc9d, 0x1bc9e], [0x1bca0, 0x1bca3], [0x1d167, 0x1d169],
    [0x1d173, 0x1d182], [0x1d185, 0x1d18b], [0x1d1aa, 0x1d1ad],
    [0x1d242, 0x1d244], [0x1da00, 0x1da36], [0x1da3b, 0x1da6c],
    [0x1da75, 0x1da75], [0x1da84, 0x1da84], [0x1da9b, 0x1da9f],
    [0x1daa1, 0x1daaf], [0x1e000, 0x1e006], [0x1e008, 0x1e018],
    [0x1e01b, 0x1e021], [0x1e023, 0x1e024], [0x1e026, 0x1e02a],
    [0x1e8d0, 0x1e8d6], [0x1e944, 0x1e94a], [0xe0001, 0xe0001],
    [0xe0020, 0xe007f], [0xe0100, 0xe01ef],
];

// Sorted list of non-overlapping intervals of East Asian Ambiguous characters
// generated by the `./ranges.py` helper.
lib.wc.ambiguous = [
    [0x00a1, 0x00a1], [0x00a4, 0x00a4], [0x00a7, 0x00a8],
    [0x00aa, 0x00aa], [0x00ad, 0x00ae], [0x00b0, 0x00b4],
    [0x00b6, 0x00ba], [0x00bc, 0x00bf], [0x00c6, 0x00c6],
    [0x00d0, 0x00d0], [0x00d7, 0x00d8], [0x00de, 0x00e1],
    [0x00e6, 0x00e6], [0x00e8, 0x00ea], [0x00ec, 0x00ed],
    [0x00f0, 0x00f0], [0x00f2, 0x00f3], [0x00f7, 0x00fa],
    [0x00fc, 0x00fc], [0x00fe, 0x00fe], [0x0101, 0x0101],
    [0x0111, 0x0111], [0x0113, 0x0113], [0x011b, 0x011b],
    [0x0126, 0x0127], [0x012b, 0x012b], [0x0131, 0x0133],
    [0x0138, 0x0138], [0x013f, 0x0142], [0x0144, 0x0144],
    [0x0148, 0x014b], [0x014d, 0x014d], [0x0152, 0x0153],
    [0x0166, 0x0167], [0x016b, 0x016b], [0x01ce, 0x01ce],
    [0x01d0, 0x01d0], [0x01d2, 0x01d2], [0x01d4, 0x01d4],
    [0x01d6, 0x01d6], [0x01d8, 0x01d8], [0x01da, 0x01da],
    [0x01dc, 0x01dc], [0x0251, 0x0251], [0x0261, 0x0261],
    [0x02c4, 0x02c4], [0x02c7, 0x02c7], [0x02c9, 0x02cb],
    [0x02cd, 0x02cd], [0x02d0, 0x02d0], [0x02d8, 0x02db],
    [0x02dd, 0x02dd], [0x02df, 0x02df], [0x0300, 0x036f],
    [0x0391, 0x03a1], [0x03a3, 0x03a9], [0x03b1, 0x03c1],
    [0x03c3, 0x03c9], [0x0401, 0x0401], [0x0410, 0x044f],
    [0x0451, 0x0451], [0x1100, 0x115f], [0x2010, 0x2010],
    [0x2013, 0x2016], [0x2018, 0x2019], [0x201c, 0x201d],
    [0x2020, 0x2022], [0x2024, 0x2027], [0x2030, 0x2030],
    [0x2032, 0x2033], [0x2035, 0x2035], [0x203b, 0x203b],
    [0x203e, 0x203e], [0x2074, 0x2074], [0x207f, 0x207f],
    [0x2081, 0x2084], [0x20ac, 0x20ac], [0x2103, 0x2103],
    [0x2105, 0x2105], [0x2109, 0x2109], [0x2113, 0x2113],
    [0x2116, 0x2116], [0x2121, 0x2122], [0x2126, 0x2126],
    [0x212b, 0x212b], [0x2153, 0x2154], [0x215b, 0x215e],
    [0x2160, 0x216b], [0x2170, 0x2179], [0x2189, 0x2189],
    [0x2190, 0x2199], [0x21b8, 0x21b9], [0x21d2, 0x21d2],
    [0x21d4, 0x21d4], [0x21e7, 0x21e7], [0x2200, 0x2200],
    [0x2202, 0x2203], [0x2207, 0x2208], [0x220b, 0x220b],
    [0x220f, 0x220f], [0x2211, 0x2211], [0x2215, 0x2215],
    [0x221a, 0x221a], [0x221d, 0x2220], [0x2223, 0x2223],
    [0x2225, 0x2225], [0x2227, 0x222c], [0x222e, 0x222e],
    [0x2234, 0x2237], [0x223c, 0x223d], [0x2248, 0x2248],
    [0x224c, 0x224c], [0x2252, 0x2252], [0x2260, 0x2261],
    [0x2264, 0x2267], [0x226a, 0x226b], [0x226e, 0x226f],
    [0x2282, 0x2283], [0x2286, 0x2287], [0x2295, 0x2295],
    [0x2299, 0x2299], [0x22a5, 0x22a5], [0x22bf, 0x22bf],
    [0x2312, 0x2312], [0x231a, 0x231b], [0x2329, 0x232a],
    [0x23e9, 0x23ec], [0x23f0, 0x23f0], [0x23f3, 0x23f3],
    [0x2460, 0x24e9], [0x24eb, 0x254b], [0x2550, 0x2573],
    [0x2580, 0x258f], [0x2592, 0x2595], [0x25a0, 0x25a1],
    [0x25a3, 0x25a9], [0x25b2, 0x25b3], [0x25b6, 0x25b7],
    [0x25bc, 0x25bd], [0x25c0, 0x25c1], [0x25c6, 0x25c8],
    [0x25cb, 0x25cb], [0x25ce, 0x25d1], [0x25e2, 0x25e5],
    [0x25ef, 0x25ef], [0x25fd, 0x25fe], [0x2605, 0x2606],
    [0x2609, 0x2609], [0x260e, 0x260f], [0x2614, 0x2615],
    [0x261c, 0x261c], [0x261e, 0x261e], [0x2640, 0x2640],
    [0x2642, 0x2642], [0x2648, 0x2653], [0x2660, 0x2661],
    [0x2663, 0x2665], [0x2667, 0x266a], [0x266c, 0x266d],
    [0x266f, 0x266f], [0x267f, 0x267f], [0x2693, 0x2693],
    [0x269e, 0x269f], [0x26a1, 0x26a1], [0x26aa, 0x26ab],
    [0x26bd, 0x26bf], [0x26c4, 0x26e1], [0x26e3, 0x26e3],
    [0x26e8, 0x26ff], [0x2705, 0x2705], [0x270a, 0x270b],
    [0x2728, 0x2728], [0x273d, 0x273d], [0x274c, 0x274c],
    [0x274e, 0x274e], [0x2753, 0x2755], [0x2757, 0x2757],
    [0x2776, 0x277f], [0x2795, 0x2797], [0x27b0, 0x27b0],
    [0x27bf, 0x27bf], [0x2b1b, 0x2b1c], [0x2b50, 0x2b50],
    [0x2b55, 0x2b59], [0x2e80, 0x2fdf], [0x2ff0, 0x303e],
    [0x3040, 0x4dbf], [0x4e00, 0xa4cf], [0xa960, 0xa97f],
    [0xac00, 0xd7a3], [0xe000, 0xfaff], [0xfe00, 0xfe19],
    [0xfe30, 0xfe6f], [0xff01, 0xff60], [0xffe0, 0xffe6],
    [0xfffd, 0xfffd], [0x16fe0, 0x16fe1], [0x17000, 0x18aff],
    [0x1b000, 0x1b12f], [0x1b170, 0x1b2ff], [0x1f004, 0x1f004],
    [0x1f0cf, 0x1f0cf], [0x1f100, 0x1f10a], [0x1f110, 0x1f12d],
    [0x1f130, 0x1f169], [0x1f170, 0x1f1ac], [0x1f200, 0x1f202],
    [0x1f210, 0x1f23b], [0x1f240, 0x1f248], [0x1f250, 0x1f251],
    [0x1f260, 0x1f265], [0x1f300, 0x1f320], [0x1f32d, 0x1f335],
    [0x1f337, 0x1f37c], [0x1f37e, 0x1f393], [0x1f3a0, 0x1f3ca],
    [0x1f3cf, 0x1f3d3], [0x1f3e0, 0x1f3f0], [0x1f3f4, 0x1f3f4],
    [0x1f3f8, 0x1f43e], [0x1f440, 0x1f440], [0x1f442, 0x1f4fc],
    [0x1f4ff, 0x1f53d], [0x1f54b, 0x1f54e], [0x1f550, 0x1f567],
    [0x1f57a, 0x1f57a], [0x1f595, 0x1f596], [0x1f5a4, 0x1f5a4],
    [0x1f5fb, 0x1f64f], [0x1f680, 0x1f6c5], [0x1f6cc, 0x1f6cc],
    [0x1f6d0, 0x1f6d2], [0x1f6eb, 0x1f6ec], [0x1f6f4, 0x1f6f9],
    [0x1f910, 0x1f93e], [0x1f940, 0x1f970], [0x1f973, 0x1f976],
    [0x1f97a, 0x1f97a], [0x1f97c, 0x1f9a2], [0x1f9b0, 0x1f9b9],
    [0x1f9c0, 0x1f9c2], [0x1f9d0, 0x1f9ff], [0x20000, 0x2fffd],
    [0x30000, 0x3fffd], [0xe0100, 0xe01ef], [0xf0000, 0xffffd],
    [0x100000, 0x10fffd],
];

// Sorted list of non-overlapping intervals of East Asian Unambiguous characters
// generated by the `./ranges.py` helper.
lib.wc.unambiguous = [
    [0x1100, 0x115f], [0x231a, 0x231b], [0x2329, 0x232a],
    [0x23e9, 0x23ec], [0x23f0, 0x23f0], [0x23f3, 0x23f3],
    [0x25fd, 0x25fe], [0x2614, 0x2615], [0x2648, 0x2653],
    [0x267f, 0x267f], [0x2693, 0x2693], [0x26a1, 0x26a1],
    [0x26aa, 0x26ab], [0x26bd, 0x26be], [0x26c4, 0x26c5],
    [0x26ce, 0x26ce], [0x26d4, 0x26d4], [0x26ea, 0x26ea],
    [0x26f2, 0x26f3], [0x26f5, 0x26f5], [0x26fa, 0x26fa],
    [0x26fd, 0x26fd], [0x2705, 0x2705], [0x270a, 0x270b],
    [0x2728, 0x2728], [0x274c, 0x274c], [0x274e, 0x274e],
    [0x2753, 0x2755], [0x2757, 0x2757], [0x2795, 0x2797],
    [0x27b0, 0x27b0], [0x27bf, 0x27bf], [0x2b1b, 0x2b1c],
    [0x2b50, 0x2b50], [0x2b55, 0x2b55], [0x2e80, 0x2fdf],
    [0x2ff0, 0x303e], [0x3040, 0x3247], [0x3250, 0x4dbf],
    [0x4e00, 0xa4cf], [0xa960, 0xa97f], [0xac00, 0xd7a3],
    [0xf900, 0xfaff], [0xfe10, 0xfe19], [0xfe30, 0xfe6f],
    [0xff01, 0xff60], [0xffe0, 0xffe6], [0x16fe0, 0x16fe1],
    [0x17000, 0x18aff], [0x1b000, 0x1b12f], [0x1b170, 0x1b2ff],
    [0x1f004, 0x1f004], [0x1f0cf, 0x1f0cf], [0x1f18e, 0x1f18e],
    [0x1f191, 0x1f19a], [0x1f200, 0x1f202], [0x1f210, 0x1f23b],
    [0x1f240, 0x1f248], [0x1f250, 0x1f251], [0x1f260, 0x1f265],
    [0x1f300, 0x1f320], [0x1f32d, 0x1f335], [0x1f337, 0x1f37c],
    [0x1f37e, 0x1f393], [0x1f3a0, 0x1f3ca], [0x1f3cf, 0x1f3d3],
    [0x1f3e0, 0x1f3f0], [0x1f3f4, 0x1f3f4], [0x1f3f8, 0x1f43e],
    [0x1f440, 0x1f440], [0x1f442, 0x1f4fc], [0x1f4ff, 0x1f53d],
    [0x1f54b, 0x1f54e], [0x1f550, 0x1f567], [0x1f57a, 0x1f57a],
    [0x1f595, 0x1f596], [0x1f5a4, 0x1f5a4], [0x1f5fb, 0x1f64f],
    [0x1f680, 0x1f6c5], [0x1f6cc, 0x1f6cc], [0x1f6d0, 0x1f6d2],
    [0x1f6eb, 0x1f6ec], [0x1f6f4, 0x1f6f9], [0x1f910, 0x1f93e],
    [0x1f940, 0x1f970], [0x1f973, 0x1f976], [0x1f97a, 0x1f97a],
    [0x1f97c, 0x1f9a2], [0x1f9b0, 0x1f9b9], [0x1f9c0, 0x1f9c2],
    [0x1f9d0, 0x1f9ff], [0x20000, 0x2fffd], [0x30000, 0x3fffd],
];

/**
 * Binary search to check if the given unicode character is in the table.
 *
 * @param {integer} ucs A unicode character code.
 * @param {Object} table A sorted list of internals to match against.
 * @return {boolean} True if the given character is in the table.
 */
lib.wc.binaryTableSearch_ = function(ucs, table) {
  var min = 0, max = table.length - 1;
  var mid;

  if (ucs < table[min][0] || ucs > table[max][1])
    return false;
  while (max >= min) {
    mid = Math.floor((min + max) / 2);
    if (ucs > table[mid][1]) {
      min = mid + 1;
    } else if (ucs < table[mid][0]) {
      max = mid - 1;
    } else {
      return true;
    }
  }

  return false;
};

/**
 * Binary search to check if the given unicode character is a space character.
 *
 * @param {integer} ucs A unicode character code.
 *
 * @return {boolean} True if the given character is a space character; false
 *     otherwise.
 */
lib.wc.isSpace = function(ucs) {
  return lib.wc.binaryTableSearch_(ucs, lib.wc.combining);
};

/**
 * Auxiliary function for checking if the given unicode character is a East
 * Asian Ambiguous character.
 *
 * @param {integer} ucs A unicode character code.
 *
 * @return {boolean} True if the given character is a East Asian Ambiguous
 * character.
 */
lib.wc.isCjkAmbiguous = function(ucs) {
  return lib.wc.binaryTableSearch_(ucs, lib.wc.ambiguous);
};

/**
 * Determine the column width of the given character.
 *
 * @param {integer} ucs A unicode character code.
 *
 * @return {integer} The column width of the given character.
 */
lib.wc.charWidth = function(ucs) {
  if (lib.wc.regardCjkAmbiguous) {
    return lib.wc.charWidthRegardAmbiguous(ucs);
  } else {
    return lib.wc.charWidthDisregardAmbiguous(ucs);
  }
};

/**
 * Determine the column width of the given character without considering East
 * Asian Ambiguous characters.
 *
 * @param {integer} ucs A unicode character code.
 *
 * @return {integer} The column width of the given character.
 */
lib.wc.charWidthDisregardAmbiguous = function(ucs) {
  // Optimize for ASCII characters.
  if (ucs < 0x7f) {
    if (ucs >= 0x20)
      return 1;
    else if (ucs == 0)
      return lib.wc.nulWidth;
    else /* if (ucs < 0x20) */
      return lib.wc.controlWidth;
  }

  // Test for 8-bit control characters.
  if (ucs < 0xa0)
    return lib.wc.controlWidth;

  // Binary search in table of non-spacing characters.
  if (lib.wc.isSpace(ucs))
    return 0;

  // Binary search in table of wide characters.
  return lib.wc.binaryTableSearch_(ucs, lib.wc.unambiguous) ? 2 : 1;
};

/**
 * Determine the column width of the given character considering East Asian
 * Ambiguous characters.
 *
 * @param {integer} ucs A unicode character code.
 *
 * @return {integer} The column width of the given character.
 */
lib.wc.charWidthRegardAmbiguous = function(ucs) {
  if (lib.wc.isCjkAmbiguous(ucs))
    return lib.wc.cjkAmbiguousWidth;

  return lib.wc.charWidthDisregardAmbiguous(ucs);
};

/**
 * Determine the column width of the given string.
 *
 * @param {string} str A string.
 *
 * @return {integer} The column width of the given string.
 */
lib.wc.strWidth = function(str) {
  var width, rv = 0;

  for (var i = 0; i < str.length;) {
    var codePoint = str.codePointAt(i);
    width = lib.wc.charWidth(codePoint);
    if (width < 0)
      return -1;
    rv += width;
    i += (codePoint <= 0xffff) ? 1 : 2;
  }

  return rv;
};

/**
 * Get the substring at the given column offset of the given column width.
 *
 * @param {string} str The string to get substring from.
 * @param {integer} start The starting column offset to get substring.
 * @param {integer} opt_width The column width of the substring.
 *
 * @return {string} The substring.
 */
lib.wc.substr = function(str, start, opt_width) {
  var startIndex = 0;
  var endIndex, width;

  // Fun edge case: Normally we associate zero width codepoints (like combining
  // characters) with the previous codepoint, so we skip any leading ones while
  // including trailing ones.  However, if there are zero width codepoints at
  // the start of the string, and the substring starts at 0, lets include them
  // in the result.  This also makes for a simple optimization for a common
  // request.
  if (start) {
    for (width = 0; startIndex < str.length;) {
      const codePoint = str.codePointAt(startIndex);
      width += lib.wc.charWidth(codePoint);
      if (width > start)
        break;
      startIndex += (codePoint <= 0xffff) ? 1 : 2;
    }
  }

  if (opt_width != undefined) {
    for (endIndex = startIndex, width = 0; endIndex < str.length;) {
      const codePoint = str.codePointAt(endIndex);
      width += lib.wc.charWidth(codePoint);
      if (width > opt_width)
        break;
      endIndex += (codePoint <= 0xffff) ? 1 : 2;
    }
    return str.substring(startIndex, endIndex);
  }

  return str.substr(startIndex);
};

/**
 * Get substring at the given start and end column offset.
 *
 * @param {string} str The string to get substring from.
 * @param {integer} start The starting column offset.
 * @param {integer} end The ending column offset.
 *
 * @return {string} The substring.
 */
lib.wc.substring = function(str, start, end) {
  return lib.wc.substr(str, start, end - start);
};
lib.resource.add('libdot/changelog/version', 'text/plain',
'1.25'
);

lib.resource.add('libdot/changelog/date', 'text/plain',
'2018-12-02, Minor improvements.'
);

// SOURCE FILE: hterm/js/hterm.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

lib.rtdep('lib.Storage');

/**
 * @fileoverview Declares the hterm.* namespace and some basic shared utilities
 * that are too small to deserve dedicated files.
 */
var hterm = {};

/**
 * The type of window hosting hterm.
 *
 * This is set as part of hterm.init().  The value is invalid until
 * initialization completes.
 */
hterm.windowType = null;

/**
 * The OS we're running under.
 *
 * Used when setting up OS-specific behaviors.
 *
 * This is set as part of hterm.init().  The value is invalid until
 * initialization completes.
 */
hterm.os = null;

/**
 * Warning message to display in the terminal when browser zoom is enabled.
 *
 * You can replace it with your own localized message.
 */
hterm.zoomWarningMessage = 'ZOOM != 100%';

/**
 * Brief overlay message displayed when text is copied to the clipboard.
 *
 * By default it is the unicode BLACK SCISSORS character, but you can
 * replace it with your own localized message.
 *
 * This is only displayed when the 'enable-clipboard-notice' preference
 * is enabled.
 */
hterm.notifyCopyMessage = '\u2702';


/**
 * Text shown in a desktop notification for the terminal
 * bell.  \u226a is a unicode EIGHTH NOTE, %(title) will
 * be replaced by the terminal title.
 */
hterm.desktopNotificationTitle = '\u266A %(title) \u266A';

/**
 * List of known hterm test suites.
 *
 * A test harness should ensure that they all exist before running.
 */
hterm.testDeps = ['hterm.AccessibilityReader.Tests', 'hterm.ScrollPort.Tests',
                  'hterm.Screen.Tests', 'hterm.Terminal.Tests',
                  'hterm.VT.Tests', 'hterm.VT.CannedTests'];

/**
 * The hterm init function, registered with lib.registerInit().
 *
 * This is called during lib.init().
 *
 * @param {function} onInit The function lib.init() wants us to invoke when
 *     initialization is complete.
 */
lib.registerInit('hterm', function(onInit) {
  function initOs(os) {
    hterm.os = os;

    onInit();
  }

  function initMessageManager() {
    lib.i18n.getAcceptLanguages((languages) => {
      if (!hterm.messageManager)
        hterm.messageManager = new lib.MessageManager(languages);

      // If OS detection fails, then we'll still set the value to something.
      // The OS logic in hterm tends to be best effort anyways.
      lib.f.getOs().then(initOs).catch(initOs);
    });
  }

  function onWindow(window) {
    hterm.windowType = window.type;
    initMessageManager();
  }

  function onTab(tab) {
    if (tab && window.chrome) {
      chrome.windows.get(tab.windowId, null, onWindow);
    } else {
      // TODO(rginda): This is where we end up for a v1 app's background page.
      // Maybe windowType = 'none' would be more appropriate, or something.
      hterm.windowType = 'normal';
      initMessageManager();
    }
  }

  if (!hterm.defaultStorage) {
    if (window.chrome && chrome.storage && chrome.storage.sync) {
      hterm.defaultStorage = new lib.Storage.Chrome(chrome.storage.sync);
    } else {
      hterm.defaultStorage = new lib.Storage.Local();
    }
  }

  // The chrome.tabs API is not supported in packaged apps, and detecting if
  // you're a packaged app is a little awkward.
  var isPackagedApp = false;
  if (window.chrome && chrome.runtime && chrome.runtime.getManifest) {
    var manifest = chrome.runtime.getManifest();
    isPackagedApp = manifest.app && manifest.app.background;
  }

  if (isPackagedApp) {
    // Packaged apps are never displayed in browser tabs.
    setTimeout(onWindow.bind(null, {type: 'popup'}), 0);
  } else {
    if (window.chrome && chrome.tabs) {
      // The getCurrent method gets the tab that is "currently running", not the
      // topmost or focused tab.
      chrome.tabs.getCurrent(onTab);
    } else {
      setTimeout(onWindow.bind(null, {type: 'normal'}), 0);
    }
  }
});

/**
 * Return decimal { width, height } for a given dom node.
 */
hterm.getClientSize = function(dom) {
  return dom.getBoundingClientRect();
};

/**
 * Return decimal width for a given dom node.
 */
hterm.getClientWidth = function(dom) {
  return dom.getBoundingClientRect().width;
};

/**
 * Return decimal height for a given dom node.
 */
hterm.getClientHeight = function(dom) {
  return dom.getBoundingClientRect().height;
};

/**
 * Copy the specified text to the system clipboard.
 *
 * We'll create selections on demand based on the content to copy.
 *
 * @param {HTMLDocument} document The document with the selection to copy.
 * @param {string} str The string data to copy out.
 */
hterm.copySelectionToClipboard = function(document, str) {
  // Request permission if need be.
  const requestPermission = () => {
    // Use the Permissions API if available.
    if (navigator.permissions && navigator.permissions.query) {
      return navigator.permissions.query({name: 'clipboard-write'})
        .then((status) => {
          const checkState = (resolve, reject) => {
            switch (status.state) {
              case 'granted':
                return resolve();
              case 'denied':
                return reject();
              default:
                // Wait for the user to approve/disprove.
                return new Promise((resolve, reject) => {
                  status.onchange = () => checkState(resolve, reject);
                });
            }
          };

          return new Promise(checkState);
        })
        // If the platform doesn't support "clipboard-write", or is denied,
        // we move on to the copying step anyways.
        .catch(() => Promise.resolve());
    } else {
      // No permissions API, so resolve right away.
      return Promise.resolve();
    }
  };

  // Write to the clipboard.
  const writeClipboard = () => {
    // Use the Clipboard API if available.
    if (navigator.clipboard && navigator.clipboard.writeText) {
      // If this fails (perhaps due to focus changing windows), fallback to the
      // legacy copy method.
      return navigator.clipboard.writeText(str)
        .catch(execCommand);
    } else {
      // No Clipboard API, so use the old execCommand style.
      return execCommand();
    }
  };

  // Write to the clipboard using the legacy execCommand method.
  // TODO: Once we can rely on the Clipboard API everywhere, we can simplify
  // this a lot by deleting the custom selection logic.
  const execCommand = () => {
    const copySource = document.createElement('pre');
    copySource.id = 'hterm:copy-to-clipboard-source';
    copySource.textContent = str;
    copySource.style.cssText = (
        '-webkit-user-select: text;' +
        '-moz-user-select: text;' +
        'position: absolute;' +
        'top: -99px');

    document.body.appendChild(copySource);

    const selection = document.getSelection();
    const anchorNode = selection.anchorNode;
    const anchorOffset = selection.anchorOffset;
    const focusNode = selection.focusNode;
    const focusOffset = selection.focusOffset;

    // FF sometimes throws NS_ERROR_FAILURE exceptions when we make this call.
    // Catch it because a failure here leaks the copySource node.
    // https://bugzilla.mozilla.org/show_bug.cgi?id=1178676
    try {
      selection.selectAllChildren(copySource);
    } catch (ex) {}

    try {
      document.execCommand('copy');
    } catch (firefoxException) {
      // Ignore this. FF throws an exception if there was an error, even
      // though the spec says just return false.
    }

    // IE doesn't support selection.extend.  This means that the selection won't
    // return on IE.
    if (selection.extend) {
      // When running in the test harness, we won't have any related nodes.
      if (anchorNode) {
        selection.collapse(anchorNode, anchorOffset);
      }
      if (focusNode) {
        selection.extend(focusNode, focusOffset);
      }
    }

    copySource.parentNode.removeChild(copySource);

    // Since execCommand is synchronous, resolve right away.
    return Promise.resolve();
  };

  // Kick it all off!
  return requestPermission().then(writeClipboard);
};

/**
 * Paste the system clipboard into the element with focus.
 *
 * Note: In Chrome/Firefox app/extension environments, you'll need the
 * "clipboardRead" permission.  In other environments, this might always
 * fail as the browser frequently blocks access for security reasons.
 *
 * @param {HTMLDocument} The document to paste into.
 * @return {boolean} True if the paste succeeded.
 */
hterm.pasteFromClipboard = function(document) {
  try {
    return document.execCommand('paste');
  } catch (firefoxException) {
    // Ignore this.  FF 40 and older would incorrectly throw an exception if
    // there was an error instead of returning false.
    return false;
  }
};

/**
 * Return a formatted message in the current locale.
 *
 * @param {string} name The name of the message to return.
 * @param {Array<string>=} args The message arguments, if required.
 * @param {string=} string The default message text.
 * @return {string} The localized message.
 */
hterm.msg = function(name, args = [], string) {
  return hterm.messageManager.get('HTERM_' + name, args, string);
};

/**
 * Create a new notification.
 *
 * @param {Object} params Various parameters for the notification.
 * @param {string} params.title The title (defaults to the window's title).
 * @param {string} params.body The message body (main text).
 */
hterm.notify = function(params) {
  var def = (curr, fallback) => curr !== undefined ? curr : fallback;
  if (params === undefined || params === null)
    params = {};

  // Merge the user's choices with the default settings.  We don't take it
  // directly in case it was stuffed with excess junk.
  var options = {
      'body': params.body,
      'icon': def(params.icon, lib.resource.getDataUrl('hterm/images/icon-96')),
  };

  var title = def(params.title, window.document.title);
  if (!title)
    title = 'hterm';
  title = lib.f.replaceVars(hterm.desktopNotificationTitle, {'title': title});

  var n = new Notification(title, options);
  n.onclick = function() {
    window.focus();
    this.close();
  };
  return n;
};

/**
 * Launches url in a new tab.
 *
 * @param {string} url URL to launch in a new tab.
 */
hterm.openUrl = function(url) {
  if (window.chrome && chrome.browser && chrome.browser.openTab) {
    // For Chrome v2 apps, we need to use this API to properly open windows.
    chrome.browser.openTab({'url': url});
  } else {
    const win = lib.f.openWindow(url, '_blank');
    win.focus();
  }
};

/**
 * Constructor for a hterm.Size record.
 *
 * Instances of this class have public read/write members for width and height.
 *
 * @param {integer} width The width of this record.
 * @param {integer} height The height of this record.
 */
hterm.Size = function(width, height) {
  this.width = width;
  this.height = height;
};

/**
 * Adjust the width and height of this record.
 *
 * @param {integer} width The new width of this record.
 * @param {integer} height The new height of this record.
 */
hterm.Size.prototype.resize = function(width, height) {
  this.width = width;
  this.height = height;
};

/**
 * Return a copy of this record.
 *
 * @return {hterm.Size} A new hterm.Size instance with the same width and
 * height.
 */
hterm.Size.prototype.clone = function() {
  return new hterm.Size(this.width, this.height);
};

/**
 * Set the height and width of this instance based on another hterm.Size.
 *
 * @param {hterm.Size} that The object to copy from.
 */
hterm.Size.prototype.setTo = function(that) {
  this.width = that.width;
  this.height = that.height;
};

/**
 * Test if another hterm.Size instance is equal to this one.
 *
 * @param {hterm.Size} that The other hterm.Size instance.
 * @return {boolean} True if both instances have the same width/height, false
 *     otherwise.
 */
hterm.Size.prototype.equals = function(that) {
  return this.width == that.width && this.height == that.height;
};

/**
 * Return a string representation of this instance.
 *
 * @return {string} A string that identifies the width and height of this
 *     instance.
 */
hterm.Size.prototype.toString = function() {
  return '[hterm.Size: ' + this.width + ', ' + this.height + ']';
};

/**
 * Constructor for a hterm.RowCol record.
 *
 * Instances of this class have public read/write members for row and column.
 *
 * This class includes an 'overflow' bit which is use to indicate that an
 * attempt has been made to move the cursor column passed the end of the
 * screen.  When this happens we leave the cursor column set to the last column
 * of the screen but set the overflow bit.  In this state cursor movement
 * happens normally, but any attempt to print new characters causes a cr/lf
 * first.
 *
 * @param {integer} row The row of this record.
 * @param {integer} column The column of this record.
 * @param {boolean} opt_overflow Optional boolean indicating that the RowCol
 *     has overflowed.
 */
hterm.RowCol = function(row, column, opt_overflow) {
  this.row = row;
  this.column = column;
  this.overflow = !!opt_overflow;
};

/**
 * Adjust the row and column of this record.
 *
 * @param {integer} row The new row of this record.
 * @param {integer} column The new column of this record.
 * @param {boolean} opt_overflow Optional boolean indicating that the RowCol
 *     has overflowed.
 */
hterm.RowCol.prototype.move = function(row, column, opt_overflow) {
  this.row = row;
  this.column = column;
  this.overflow = !!opt_overflow;
};

/**
 * Return a copy of this record.
 *
 * @return {hterm.RowCol} A new hterm.RowCol instance with the same row and
 * column.
 */
hterm.RowCol.prototype.clone = function() {
  return new hterm.RowCol(this.row, this.column, this.overflow);
};

/**
 * Set the row and column of this instance based on another hterm.RowCol.
 *
 * @param {hterm.RowCol} that The object to copy from.
 */
hterm.RowCol.prototype.setTo = function(that) {
  this.row = that.row;
  this.column = that.column;
  this.overflow = that.overflow;
};

/**
 * Test if another hterm.RowCol instance is equal to this one.
 *
 * @param {hterm.RowCol} that The other hterm.RowCol instance.
 * @return {boolean} True if both instances have the same row/column, false
 *     otherwise.
 */
hterm.RowCol.prototype.equals = function(that) {
  return (this.row == that.row && this.column == that.column &&
          this.overflow == that.overflow);
};

/**
 * Return a string representation of this instance.
 *
 * @return {string} A string that identifies the row and column of this
 *     instance.
 */
hterm.RowCol.prototype.toString = function() {
  return ('[hterm.RowCol: ' + this.row + ', ' + this.column + ', ' +
          this.overflow + ']');
};
// SOURCE FILE: hterm/js/hterm_accessibility_reader.js
// Copyright 2018 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

/**
 * AccessibilityReader responsible for rendering command output for AT.
 *
 * Renders command output for Assistive Technology using a live region. We don't
 * use the visible rows of the terminal for rendering command output to the
 * screen reader because the rendered content may be different from what we want
 * read out by a screen reader. For example, we may not actually render every
 * row of a large piece of output to the screen as it wouldn't be performant.
 * But we want the screen reader to read it all out in order.
 *
 * @param {HTMLDivElement} div The div element where the live region should be
 *     added.
 */
hterm.AccessibilityReader = function(div) {
  this.document_ = div.ownerDocument;

  // The live region element to add text to.
  const liveRegion = this.document_.createElement('div');
  liveRegion.id = 'hterm:accessibility-live-region';
  liveRegion.style.cssText = `position: absolute;
                              width: 0; height: 0;
                              overflow: hidden;
                              left: 0; top: 0;`;
  div.appendChild(liveRegion);

  // Whether command output should be rendered for Assistive Technology.
  // This isn't always enabled because it has an impact on performance.
  this.accessibilityEnabled = false;

  // This live element is used for command output.
  this.liveElement_ = this.document_.createElement('p');
  this.liveElement_.setAttribute('aria-live', 'polite');
  this.liveElement_.setAttribute('aria-label', '');
  liveRegion.appendChild(this.liveElement_);

  // This live element is used for speaking out the current screen when
  // navigating through the scrollback buffer. It will interrupt existing
  // announcements.
  this.assertiveLiveElement_ = this.document_.createElement('p');
  this.assertiveLiveElement_.setAttribute('aria-live', 'assertive');
  this.assertiveLiveElement_.setAttribute('aria-label', '');
  liveRegion.appendChild(this.assertiveLiveElement_);

  // A queue of updates to announce.
  this.queue_ = [];

  // A timer which tracks when next to add items to the live region. null when
  // not running. This is used to combine updates that occur in a small window,
  // as well as to avoid too much output being added to the live region in one
  // go which can cause the renderer to hang.
  this.nextReadTimer_ = null;

  // This is set to true if the cursor is about to update position on the
  // screen. i.e. beforeCursorChange has been called but not afterCursorChange.
  this.cursorIsChanging_ = false;

  // This tracks changes that would be added to queue_ while the cursor is
  // changing. This is done so that we can decide to discard these changes if
  // we announce something as a result of the cursor change.
  this.cursorChangeQueue_ = [];

  // The string of text on the row that the cursor was last on. Only valid while
  // cursorIsChanging_ is true.
  this.lastCursorRowString_ = null;

  // The row that the cursor was last on. Only valid while cursorIsChanging_ is
  // true.
  this.lastCursorRow_ = null;

  // The column that the cursor was last on. Only valid while cursorIsChanging_
  // is true.
  this.lastCursorColumn_ = null;

  // True if a keypress has been performed since the last cursor change.
  this.hasUserGesture = false;
};

/**
 * Delay in ms to use for merging strings to output.
 *
 * We merge strings together to avoid hanging the terminal and to ensure that
 * aria updates make it to the screen reader. We want this to be short so
 * there's not a big delay between typing/executing commands and hearing output.
 *
 * @constant
 * @type {integer}
 */
hterm.AccessibilityReader.DELAY = 50;

/**
 * Enable accessibility-friendly features that have a performance impact.
 *
 * @param {boolean} enabled Whether to enable accessibility-friendly features.
 */
hterm.AccessibilityReader.prototype.setAccessibilityEnabled =
    function(enabled) {
  if (!enabled) {
    this.clear();
  }

  this.accessibilityEnabled = enabled;
};

/**
 * Decorate the document where the terminal <x-screen> resides. This is needed
 * for listening to keystrokes on the screen.
 *
 * @param {HTMLDocument} doc The document where the <x-screen> resides.
 */
hterm.AccessibilityReader.prototype.decorate = function(doc) {
  const handlers = ['keydown', 'keypress', 'keyup', 'textInput'];
  handlers.forEach((handler) => {
    doc.addEventListener(handler, () => { this.hasUserGesture = true; });
  });
};

/**
 * This should be called before the cursor on the screen is about to get
 * updated. This allows cursor changes to be tracked and related notifications
 * to be announced.
 *
 * @param {string} cursorRowString The text in the row that the cursor is
 *     currently on.
 * @param {integer} cursorRow The index of the row that the cursor is currently
 *     on, including rows in the scrollback buffer.
 * @param {integer} cursorColumn The index of the column that the cursor is
 *     currently on.
 */
hterm.AccessibilityReader.prototype.beforeCursorChange =
    function(cursorRowString, cursorRow, cursorColumn) {
  // If accessibility is enabled we don't announce selection changes as these
  // can have a performance impact.
  if (!this.accessibilityEnabled) {
    return;
  }

  // If there is no user gesture that can be tied to the cursor change, we
  // don't want to announce anything.
  if (!this.hasUserGesture || this.cursorIsChanging_) {
    return;
  }

  this.cursorIsChanging_ = true;
  this.lastCursorRowString_ = cursorRowString;
  this.lastCursorRow_ = cursorRow;
  this.lastCursorColumn_ = cursorColumn;
};

/**
 * This should be called after the cursor on the screen has been updated. Note
 * that several updates to the cursor may have happened between
 * beforeCursorChange and afterCursorChange.
 *
 * This allows cursor changes to be tracked and related notifications to be
 * announced.
 *
 * @param {string} cursorRowString The text in the row that the cursor is
 *     currently on.
 * @param {integer} cursorRow The index of the row that the cursor is currently
 *     on, including rows in the scrollback buffer.
 * @param {integer} cursorColumn The index of the column that the cursor is
 *     currently on.
 */
hterm.AccessibilityReader.prototype.afterCursorChange =
    function(cursorRowString, cursorRow, cursorColumn) {
  // This can happen if clear() is called midway through a cursor change.
  if (!this.cursorIsChanging_) {
    return;
  }
  this.cursorIsChanging_ = false;

  if (!this.announceAction_(cursorRowString, cursorRow, cursorColumn)) {
    // If we don't announce a special action, we re-queue all the output that
    // was queued during the selection change.
    for (let i = 0; i < this.cursorChangeQueue_.length; ++i) {
      this.announce(this.cursorChangeQueue_[i]);
    }
  }

  this.cursorChangeQueue_ = [];
  this.lastCursorRowString_ = null;
  this.lastCursorRow_ = null;
  this.lastCursorColumn_ = null;
  this.hasUserGesture = false;
};

/**
 * Announce the command output.
 *
 * @param {string} str The string to announce using a live region.
 */
hterm.AccessibilityReader.prototype.announce = function(str) {
  if (!this.accessibilityEnabled) {
    return;
  }

  // If the cursor is in the middle of changing, we queue up the output
  // separately as we may not want it to be announced if it's part of a cursor
  // change announcement.
  if (this.cursorIsChanging_) {
    this.cursorChangeQueue_.push(str);
    return;
  }

  // Don't append newlines to the queue if the queue is empty. It won't have any
  // impact.
  if (str == '\n' && this.queue_.length > 0) {
    this.queue_.push('');
    // We don't need to trigger an announcement on newlines because they won't
    // change the existing content that's output.
    return;
  }

  if (this.queue_.length == 0) {
    this.queue_.push(str);
  } else {
    // We put a space between strings that appear on the same line.
    // TODO(raymes): We should check the location on the row and not add a space
    // if the strings are joined together.
    let padding = '';
    if (this.queue_[this.queue_.length - 1].length != 0) {
      padding = ' ';
    }
    this.queue_[this.queue_.length - 1] += padding + str;
  }

  // If we've already scheduled text being added to the live region, wait for it
  // to happen.
  if (this.nextReadTimer_) {
    return;
  }

  // If there's only one item in the queue, we may get other text being added
  // very soon after. In that case, wait a small delay so we can merge the
  // related strings.
  if (this.queue_.length == 1) {
    this.nextReadTimer_ = setTimeout(this.addToLiveRegion_.bind(this),
                                     hterm.AccessibilityReader.DELAY);
  } else {
    throw new Error(
        'Expected only one item in queue_ or nextReadTimer_ to be running.');
  }
};

/**
 * Voice an announcement that will interrupt other announcements.
 *
 * @param {string} str The string to announce using a live region.
 */
hterm.AccessibilityReader.prototype.assertiveAnnounce = function(str) {
  if (this.hasUserGesture && str == ' ') {
    str = hterm.msg('SPACE_CHARACTER', [], 'Space');
  }

  // If the same string is announced twice, an attribute change won't be
  // registered and the screen reader won't know that the string has changed.
  // So we slightly change the string to ensure that the attribute change gets
  // registered.
  str = str.trim();
  if (str == this.assertiveLiveElement_.getAttribute('aria-label')) {
    str = '\n' + str;
  }

  this.clear();
  this.assertiveLiveElement_.setAttribute('aria-label', str);
};

/**
 * Add a newline to the text that will be announced to the live region.
 */
hterm.AccessibilityReader.prototype.newLine = function() {
  this.announce('\n');
};

/**
 * Clear the live region and any in-flight announcements.
 */
hterm.AccessibilityReader.prototype.clear = function() {
  this.liveElement_.setAttribute('aria-label', '');
  this.assertiveLiveElement_.setAttribute('aria-label', '');
  clearTimeout(this.nextReadTimer_);
  this.nextReadTimer_ = null;
  this.queue_ = [];

  this.cursorIsChanging_ = false;
  this.cursorChangeQueue_ = [];
  this.lastCursorRowString_ = null;
  this.lastCursorRow_ = null;
  this.lastCursorColumn_ = null;
  this.hasUserGesture = false;
};

/**
 * This will announce an action that is related to a cursor change, for example
 * when the user deletes a character we want the character deleted to be
 * announced. Similarly, when the user moves the cursor along the line, we want
 * the characters selected to be announced.
 *
 * Note that this function is a heuristic. Because of the nature of terminal
 * emulators, we can't distinguish input and output, which means we don't really
 * know what output is the result of a keypress and what isn't. Also in some
 * terminal applications certain announcements may make sense whereas others may
 * not. This function should try to account for the most common cases.
 *
 * @param {string} cursorRowString The text in the row that the cursor is
 *     currently on.
 * @param {integer} cursorRow The index of the row that the cursor is currently
 *     on, including rows in the scrollback buffer.
 * @param {integer} cursorColumn The index of the column that the cursor is
 *     currently on.
 */
hterm.AccessibilityReader.prototype.announceAction_ =
    function(cursorRowString, cursorRow, cursorColumn) {
  // If the cursor changes rows, we don't announce anything at present.
  if (this.lastCursorRow_ != cursorRow) {
    return false;
  }

  // The case when the row of text hasn't changed at all.
  if (this.lastCursorRowString_ == cursorRowString) {
    // Moving the cursor along the line. We check that no significant changes
    // have been queued. If they have, it may not just be a cursor movement and
    // it may be better to read those out.
    if (this.lastCursorColumn_ != cursorColumn &&
        this.cursorChangeQueue_.join('').trim() == '') {
      // Announce the text between the old cursor position and the new one.
      const start = Math.min(this.lastCursorColumn_, cursorColumn);
      const len = Math.abs(cursorColumn - this.lastCursorColumn_);
      this.assertiveAnnounce(
          lib.wc.substr(this.lastCursorRowString_, start, len));
      return true;
    }
    return false;
  }

  // The case when the row of text has changed.
  if (this.lastCursorRowString_ != cursorRowString) {
    // Spacebar. We manually announce this character since the screen reader may
    // not announce the whitespace in a live region.
    if (this.lastCursorColumn_ + 1 == cursorColumn) {
      if (lib.wc.substr(cursorRowString, cursorColumn - 1, 1) == ' ' &&
          this.cursorChangeQueue_.length > 0 &&
          this.cursorChangeQueue_[0] == ' ') {
        this.assertiveAnnounce(' ');
        return true;
      }
    }

    // Backspace and deletion.
    // The position of the characters deleted is right after the current
    // position of the cursor in the case of backspace and delete.
    const cursorDeleted = cursorColumn;
    // Check that the current row string is shorter than the previous. Also
    // check that the start of the strings (up to the cursor) match.
    if (lib.wc.strWidth(cursorRowString) <=
        lib.wc.strWidth(this.lastCursorRowString_) &&
        lib.wc.substr(this.lastCursorRowString_, 0, cursorDeleted) ==
        lib.wc.substr(cursorRowString, 0, cursorDeleted)) {
      // Find the length of the current row string ignoring space characters.
      // These may be inserted at the end of the string when deleting characters
      // so they should be ignored.
      let lengthOfCurrentRow = lib.wc.strWidth(cursorRowString);
      for (; lengthOfCurrentRow > 0; --lengthOfCurrentRow) {
        if (lengthOfCurrentRow == cursorDeleted ||
            lib.wc.substr(cursorRowString, lengthOfCurrentRow - 1, 1) != ' ') {
          break;
        }
      }

      const numCharsDeleted =
          lib.wc.strWidth(this.lastCursorRowString_) - lengthOfCurrentRow;

      // Check that the end of the strings match.
      const lengthOfEndOfString = lengthOfCurrentRow - cursorDeleted;
      const endOfLastRowString = lib.wc.substr(
          this.lastCursorRowString_, cursorDeleted + numCharsDeleted,
          lengthOfEndOfString);
      const endOfCurrentRowString =
          lib.wc.substr(cursorRowString, cursorDeleted, lengthOfEndOfString);
      if (endOfLastRowString == endOfCurrentRowString) {
        const deleted = lib.wc.substr(
            this.lastCursorRowString_, cursorDeleted, numCharsDeleted);
        if (deleted != '') {
          this.assertiveAnnounce(deleted);
          return true;
        }
      }
    }
    return false;
  }

  return false;
};

/**
 * Add text from queue_ to the live region.
 *
 */
hterm.AccessibilityReader.prototype.addToLiveRegion_ = function() {
  this.nextReadTimer_ = null;

  let str = this.queue_.join('\n').trim();

  // If the same string is announced twice, an attribute change won't be
  // registered and the screen reader won't know that the string has changed.
  // So we slightly change the string to ensure that the attribute change gets
  // registered.
  if (str == this.liveElement_.getAttribute('aria-label')) {
    str = '\n' + str;
  }

  this.liveElement_.setAttribute('aria-label', str);
  this.queue_ = [];
};
// SOURCE FILE: hterm/js/hterm_contextmenu.js
// Copyright 2018 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

/**
 * @fileoverview Context menu handling.
 */

/**
 * Manage the context menu usually shown when right clicking.
 */
hterm.ContextMenu = function() {
  // The document that contains this context menu.
  this.document_ = null;
  // The generated context menu (i.e. HTML elements).
  this.element_ = null;
  // The structured menu (i.e. JS objects).
  this.menu_ = [];
};

/**
 * Constant to add a separator to the context menu.
 */
hterm.ContextMenu.SEPARATOR = {};

/**
 * Bind context menu to a specific document element.
 *
 * @param {HTMLDocument} document The document to use when creating elements.
 */
hterm.ContextMenu.prototype.setDocument = function(document) {
  if (this.element_) {
    this.element_.remove();
    this.element_ = null;
  }
  this.document_ = document;
  this.regenerate_();
  this.document_.body.appendChild(this.element_);
};

/**
 * Regenerate the HTML elements based on internal menu state.
 */
hterm.ContextMenu.prototype.regenerate_ = function() {
  if (!this.element_) {
    this.element_ = this.document_.createElement('menu');
    this.element_.id = 'hterm:context-menu';
    this.element_.style.cssText = `
        display: none;
        border: solid 1px;
        position: absolute;
    `;
  } else {
    this.hide();
  }

  // Clear out existing menu entries.
  while (this.element_.firstChild) {
    this.element_.removeChild(this.element_.firstChild);
  }

  this.menu_.forEach(([name, action]) => {
    const menuitem = this.document_.createElement('menuitem');
    if (name === hterm.ContextMenu.SEPARATOR) {
      menuitem.innerHTML = '<hr>';
      menuitem.className = 'separator';
    } else {
      menuitem.innerText = name;
      menuitem.addEventListener('mousedown', function(e) {
        e.preventDefault();
        action(e);
      });
    }
    this.element_.appendChild(menuitem);
  });
};

/**
 * Set all the entries in the context menu.
 *
 * This is an array of arrays.  The first element in the array is the string to
 * display while the second element is the function to call.
 *
 * The first element may also be the SEPARATOR constant to add a separator.
 *
 * This resets all existing menu entries.
 *
 * @param {Array<Array<string, function(Event)>>} items The menu entries.
 */
hterm.ContextMenu.prototype.setItems = function(items) {
  this.menu_ = items;
  this.regenerate_();
};

/**
 * Show the context menu.
 *
 * The event is used to determine where to show the menu.
 *
 * If no menu entries are defined, then nothing will be shown.
 *
 * @param {Event} e The event triggering this display.
 * @param {hterm.Terminal=} terminal The terminal object to get style info from.
 */
hterm.ContextMenu.prototype.show = function(e, terminal) {
  // If there are no menu entries, then don't try to show anything.
  if (this.menu_.length == 0) {
    return;
  }

  // If we have the terminal, sync the style preferences over.
  if (terminal) {
    this.element_.style.backgroundColor = terminal.getBackgroundColor();
    this.element_.style.color = terminal.getForegroundColor();
    this.element_.style.fontSize = terminal.getFontSize();
    this.element_.style.fontFamily = terminal.getFontFamily();
  }

  this.element_.style.top = `${e.clientY}px`;
  this.element_.style.left = `${e.clientX}px`;
  const docSize = hterm.getClientSize(this.document_.body);

  this.element_.style.display = 'block';

  // We can't calculate sizes until after it's displayed.
  const eleSize = hterm.getClientSize(this.element_);
  // Make sure the menu isn't clipped outside of the current element.
  const minY = Math.max(0, docSize.height - eleSize.height);
  const minX = Math.max(0, docSize.width - eleSize.width);
  if (minY < e.clientY) {
    this.element_.style.top = `${minY}px`;
  }
  if (minX < e.clientX) {
    this.element_.style.left = `${minX}px`;
  }
};

/**
 * Hide the context menu.
 */
hterm.ContextMenu.prototype.hide = function() {
  if (!this.element_) {
    return;
  }

  this.element_.style.display = 'none';
};
// SOURCE FILE: hterm/js/hterm_frame.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

lib.rtdep('lib.f');

/**
 * First draft of the interface between the terminal and a third party dialog.
 *
 * This is rough.  It's just the terminal->dialog layer.  To complete things
 * we'll also need a command->terminal layer.  That will have to facilitate
 * command->terminal->dialog or direct command->dialog communication.
 *
 * I imagine this class will change significantly when that happens.
 */

/**
 * Construct a new frame for the given terminal.
 *
 * @param terminal {hterm.Terminal} The parent terminal object.
 * @param url {String} The url to load in the frame.
 * @param opt_options {Object} Optional options for the frame.  Not implemented.
 */
hterm.Frame = function(terminal, url, opt_options) {
  this.terminal_ = terminal;
  this.div_ = terminal.div_;
  this.url = url;
  this.options = opt_options || {};
  this.iframe_ = null;
  this.container_ = null;
  this.messageChannel_ = null;
};

/**
 * Handle messages from the iframe.
 */
hterm.Frame.prototype.onMessage_ = function(e) {
  switch (e.data.name) {
    case 'ipc-init-ok':
      // We get this response after we send them ipc-init and they finish.
      this.sendTerminalInfo_();
      return;
    case 'terminal-info-ok':
      // We get this response after we send them terminal-info and they finish.
      // Show the finished frame, and then rebind our message handler to the
      // callback below.
      this.container_.style.display = 'flex';
      this.postMessage('visible');
      this.messageChannel_.port1.onmessage = this.onMessage.bind(this);
      this.onLoad();
      return;
    default:
      console.log('Unknown message from frame:', e.data);
      return;
  }
};

/**
 * Clients could override this, I guess.
 *
 * It doesn't support multiple listeners, but I'm not sure that would make sense
 * here.  It's probably better to speak directly to our parents.
 */
hterm.Frame.prototype.onMessage = function() {};

/**
 * Handle iframe onLoad event.
 */
hterm.Frame.prototype.onLoad_ = function() {
  this.messageChannel_ = new MessageChannel();
  this.messageChannel_.port1.onmessage = this.onMessage_.bind(this);
  this.messageChannel_.port1.start();
  this.iframe_.contentWindow.postMessage(
      {name: 'ipc-init', argv: [{messagePort: this.messageChannel_.port2}]},
      this.url, [this.messageChannel_.port2]);
};

/**
 * Clients may override this.
 */
hterm.Frame.prototype.onLoad = function() {};

/**
 * Sends the terminal-info message to the iframe.
 */
hterm.Frame.prototype.sendTerminalInfo_ = function() {
  lib.i18n.getAcceptLanguages(function(languages) {
      this.postMessage('terminal-info', [{
         acceptLanguages: languages,
         foregroundColor: this.terminal_.getForegroundColor(),
         backgroundColor: this.terminal_.getBackgroundColor(),
         cursorColor: this.terminal_.getCursorColor(),
         fontSize: this.terminal_.getFontSize(),
         fontFamily: this.terminal_.getFontFamily(),
         baseURL: lib.f.getURL('/')
          }]
        );
    }.bind(this));
};

/**
 * User clicked the close button on the frame decoration.
 */
hterm.Frame.prototype.onCloseClicked_ = function() {
  this.close();
};

/**
 * Close this frame.
 */
hterm.Frame.prototype.close = function() {
  if (!this.container_ || !this.container_.parentNode)
      return;

  this.container_.parentNode.removeChild(this.container_);
  this.onClose();
};


/**
 * Clients may override this.
 */
hterm.Frame.prototype.onClose = function() {};

/**
 * Send a message to the iframe.
 */
hterm.Frame.prototype.postMessage = function(name, argv) {
  if (!this.messageChannel_)
    throw new Error('Message channel is not set up.');

  this.messageChannel_.port1.postMessage({name: name, argv: argv});
};

/**
 * Show the UI for this frame.
 *
 * The iframe src is not loaded until this method is called.
 */
hterm.Frame.prototype.show = function() {
  var self = this;

  function opt(name, defaultValue) {
    if (name in self.options)
      return self.options[name];

    return defaultValue;
  }

  var self = this;

  if (this.container_ && this.container_.parentNode) {
    console.error('Frame already visible');
    return;
  }

  var headerHeight = '16px';

  var divSize = hterm.getClientSize(this.div_);

  var width = opt('width', 640);
  var height = opt('height', 480);
  var left = (divSize.width - width) / 2;
  var top = (divSize.height - height) / 2;

  var document = this.terminal_.document_;

  var container = this.container_ = document.createElement('div');
  container.style.cssText = (
      'position: absolute;' +
      'display: none;' +
      'flex-direction: column;' +
      'top: 10%;' +
      'left: 4%;' +
      'width: 90%;' +
      'height: 80%;' +
      'min-height: 20%;' +
      'max-height: 80%;' +
      'box-shadow: 0 0 2px ' + this.terminal_.getForegroundColor() + ';' +
      'border: 2px ' + this.terminal_.getForegroundColor() + ' solid;');

  if (false) {
    // No use for the close button, so no use for the window header either.
    var header = document.createElement('div');
    header.style.cssText = (
        'display: flex;' +
        'justify-content: flex-end;' +
        'height: ' + headerHeight + ';' +
        'background-color: ' + this.terminal_.getForegroundColor() + ';' +
        'color: ' + this.terminal_.getBackgroundColor() + ';' +
        'font-size: 16px;' +
        'font-family: ' + this.terminal_.getFontFamily());
    container.appendChild(header);

    var button = document.createElement('div');
    button.setAttribute('role', 'button');
    button.style.cssText = (
        'margin-top: -3px;' +
        'margin-right: 3px;' +
        'cursor: pointer;');
    button.textContent = '\u2a2f';
    button.addEventListener('click', this.onCloseClicked_.bind(this));
    header.appendChild(button);
  }

  var iframe = this.iframe_ = document.createElement('iframe');
  iframe.onload = this.onLoad_.bind(this);
  iframe.style.cssText = (
      'display: flex;' +
      'flex: 1;' +
      'width: 100%');
  iframe.setAttribute('src', this.url);
  iframe.setAttribute('seamless', true);
  container.appendChild(iframe);

  this.div_.appendChild(container);
};
// SOURCE FILE: hterm/js/hterm_keyboard.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

lib.rtdep('hterm.Keyboard.KeyMap');

/**
 * Keyboard handler.
 *
 * Consumes onKey* events and invokes onVTKeystroke on the associated
 * hterm.Terminal object.
 *
 * See also: [XTERM] as referenced in vt.js.
 *
 * @param {hterm.Terminal} The Terminal object associated with this keyboard.
 */
hterm.Keyboard = function(terminal) {
  // The parent vt interpreter.
  this.terminal = terminal;

  // The element we're currently capturing keyboard events for.
  this.keyboardElement_ = null;

  // The event handlers we are interested in, and their bound callbacks, saved
  // so they can be uninstalled with removeEventListener, when required.
  this.handlers_ = [
      ['focusout', this.onFocusOut_.bind(this)],
      ['keydown', this.onKeyDown_.bind(this)],
      ['keypress', this.onKeyPress_.bind(this)],
      ['keyup', this.onKeyUp_.bind(this)],
      ['textInput', this.onTextInput_.bind(this)]
  ];

  /**
   * The current key map.
   */
  this.keyMap = new hterm.Keyboard.KeyMap(this);

  this.bindings = new hterm.Keyboard.Bindings(this);

  /**
   * none: Disable any AltGr related munging.
   * ctrl-alt: Assume Ctrl+Alt means AltGr.
   * left-alt: Assume left Alt means AltGr.
   * right-alt: Assume right Alt means AltGr.
   */
  this.altGrMode = 'none';

  /**
   * If true, Shift-Insert will fall through to the browser as a paste.
   * If false, the keystroke will be sent to the host.
   */
  this.shiftInsertPaste = true;

  /**
   * If true, home/end will control the terminal scrollbar and shift home/end
   * will send the VT keycodes.  If false then home/end sends VT codes and
   * shift home/end scrolls.
   */
  this.homeKeysScroll = false;

  /**
   * Same as above, except for page up/page down.
   */
  this.pageKeysScroll = false;

  /**
   * If true, Ctrl-Plus/Minus/Zero controls zoom.
   * If false, Ctrl-Shift-Plus/Minus/Zero controls zoom, Ctrl-Minus sends ^_,
   * Ctrl-Plus/Zero do nothing.
   */
  this.ctrlPlusMinusZeroZoom = true;

  /**
   * Ctrl+C copies if true, sends ^C to host if false.
   * Ctrl+Shift+C sends ^C to host if true, copies if false.
   */
  this.ctrlCCopy = false;

  /**
   * Ctrl+V pastes if true, sends ^V to host if false.
   * Ctrl+Shift+V sends ^V to host if true, pastes if false.
   */
  this.ctrlVPaste = false;

  /**
   * Enable/disable application keypad.
   *
   * This changes the way numeric keys are sent from the keyboard.
   */
  this.applicationKeypad = false;

  /**
   * Enable/disable the application cursor mode.
   *
   * This changes the way cursor keys are sent from the keyboard.
   */
  this.applicationCursor = false;

  /**
   * If true, the backspace should send BS ('\x08', aka ^H).  Otherwise
   * the backspace key should send '\x7f'.
   */
  this.backspaceSendsBackspace = false;

  /**
   * Set whether the meta key sends a leading escape or not.
   */
  this.metaSendsEscape = true;

  /**
   * Set whether meta-V gets passed to host.
   */
  this.passMetaV = true;

  /**
   * Controls how the alt key is handled.
   *
   *  escape....... Send an ESC prefix.
   *  8-bit........ Add 128 to the unshifted character as in xterm.
   *  browser-key.. Wait for the keypress event and see what the browser says.
   *                (This won't work well on platforms where the browser
   *                 performs a default action for some alt sequences.)
   *
   * This setting only matters when alt is distinct from meta (altIsMeta is
   * false.)
   */
  this.altSendsWhat = 'escape';

  /**
   * Set whether the alt key acts as a meta key, instead of producing 8-bit
   * characters.
   *
   * True to enable, false to disable, null to autodetect based on platform.
   */
  this.altIsMeta = false;

  /**
   * If true, tries to detect DEL key events that are from alt-backspace on
   * Chrome OS vs from a true DEL key press.
   *
   * Background: At the time of writing, on Chrome OS, alt-backspace is mapped
   * to DEL. Some users may be happy with this, but others may be frustrated
   * that it's impossible to do meta-backspace. If the user enables this pref,
   * we use a trick to tell a true DEL keypress from alt-backspace: on
   * alt-backspace, we will see the alt key go down, then get a DEL keystroke
   * that indicates that alt is not pressed. See https://crbug.com/174410 .
   */
  this.altBackspaceIsMetaBackspace = false;

  /**
   * Used to keep track of the current alt-key state, which is necessary for
   * the altBackspaceIsMetaBackspace preference above and for the altGrMode
   * preference.  This is a bitmap with where bit positions correspond to the
   * "location" property of the key event.
   */
  this.altKeyPressed = 0;

  /**
   * If true, Chrome OS media keys will be mapped to their F-key equivalent.
   * E.g. "Back" will be mapped to F1. If false, Chrome will handle the keys.
   */
  this.mediaKeysAreFKeys = false;

  /**
   * Holds the previous setting of altSendsWhat when DECSET 1039 is used. When
   * DECRST 1039 is used, altSendsWhat is changed back to this and this is
   * nulled out.
   */
  this.previousAltSendsWhat_ = null;
};

/**
 * Special handling for keyCodes in a keyboard layout.
 */
hterm.Keyboard.KeyActions = {
  /**
   * Call preventDefault and stopPropagation for this key event and nothing
   * else.
   */
  CANCEL: lib.f.createEnum('CANCEL'),

  /**
   * This performs the default terminal action for the key.  If used in the
   * 'normal' action and the the keystroke represents a printable key, the
   * character will be sent to the host.  If used in one of the modifier
   * actions, the terminal will perform the normal action after (possibly)
   * altering it.
   *
   *  - If the normal sequence starts with CSI, the sequence will be adjusted
   *    to include the modifier parameter as described in [XTERM] in the final
   *    table of the "PC-Style Function Keys" section.
   *
   *  - If the control key is down and the key represents a printable character,
   *    and the uppercase version of the unshifted keycap is between
   *    64 (ASCII '@') and 95 (ASCII '_'), then the uppercase version of the
   *    unshifted keycap minus 64 is sent.  This makes '^@' send '\x00' and
   *    '^_' send '\x1f'.  (Note that one higher that 0x1f is 0x20, which is
   *    the first printable ASCII value.)
   *
   *  - If the alt key is down and the key represents a printable character then
   *    the value of the character is shifted up by 128.
   *
   *  - If meta is down and configured to send an escape, '\x1b' will be sent
   *    before the normal action is performed.
   */
  DEFAULT: lib.f.createEnum('DEFAULT'),

  /**
   * Causes the terminal to opt out of handling the key event, instead letting
   * the browser deal with it.
   */
  PASS: lib.f.createEnum('PASS'),

  /**
   * Insert the first or second character of the keyCap, based on e.shiftKey.
   * The key will be handled in onKeyDown, and e.preventDefault() will be
   * called.
   *
   * It is useful for a modified key action, where it essentially strips the
   * modifier while preventing the browser from reacting to the key.
   */
  STRIP: lib.f.createEnum('STRIP')
};

/**
 * Capture keyboard events sent to the associated element.
 *
 * This enables the keyboard.  Captured events are consumed by this class
 * and will not perform their default action or bubble to other elements.
 *
 * Passing a null element will uninstall the keyboard handlers.
 *
 * @param {HTMLElement} element The element whose events should be captured, or
 *     null to disable the keyboard.
 */
hterm.Keyboard.prototype.installKeyboard = function(element) {
  if (element == this.keyboardElement_)
    return;

  if (element && this.keyboardElement_)
    this.installKeyboard(null);

  for (var i = 0; i < this.handlers_.length; i++) {
    var handler = this.handlers_[i];
    if (element) {
      element.addEventListener(handler[0], handler[1]);
    } else {
      this.keyboardElement_.removeEventListener(handler[0], handler[1]);
    }
  }

  this.keyboardElement_ = element;
};

/**
 * Disable keyboard event capture.
 *
 * This will allow the browser to process key events normally.
 */
hterm.Keyboard.prototype.uninstallKeyboard = function() {
  this.installKeyboard(null);
};

/**
 * Handle onTextInput events.
 *
 * These are generated when using IMEs, Virtual Keyboards (VKs), compose keys,
 * Unicode input, etc...
 */
hterm.Keyboard.prototype.onTextInput_ = function(e) {
  if (!e.data)
    return;

  // Just pass the generated buffer straight down.  No need for us to split it
  // up or otherwise parse it ahead of times.
  this.terminal.onVTKeystroke(e.data);
};

/**
 * Handle onKeyPress events.
 *
 * TODO(vapier): Drop this event entirely and only use keydown.
 */
hterm.Keyboard.prototype.onKeyPress_ = function(e) {
  // FF doesn't set keyCode reliably in keypress events.  Stick to the which
  // field here until we can move to keydown entirely.
  const key = String.fromCharCode(e.which).toLowerCase();
  if ((e.ctrlKey || e.metaKey) && (key == 'c' || key == 'v')) {
    // On FF the key press (not key down) event gets fired for copy/paste.
    // Let it fall through for the default browser behavior.
    return;
  }

  if (e.keyCode == 9 /* Tab */) {
    // On FF, a key press event will be fired in addition of key down for the
    // Tab key if key down isn't handled. This would only happen if a custom
    // PASS binding has been created and therefore this should be handled by the
    // browser.
    return;
  }

  if (e.altKey && this.altSendsWhat == 'browser-key' && e.charCode == 0) {
    // If we got here because we were expecting the browser to handle an
    // alt sequence but it didn't do it, then we might be on an OS without
    // an enabled IME system.  In that case we fall back to xterm-like
    // behavior.
    //
    // This happens here only as a fallback.  Typically these platforms should
    // set altSendsWhat to either 'escape' or '8-bit'.
    var ch = String.fromCharCode(e.keyCode);
    if (!e.shiftKey)
      ch = ch.toLowerCase();

  } else if (e.charCode >= 32) {
    ch = e.charCode;
  }

  if (ch)
    this.terminal.onVTKeystroke(String.fromCharCode(ch));

  e.preventDefault();
  e.stopPropagation();
};

/**
 * Prevent default handling for non-ctrl-shifted event.
 *
 * When combined with Chrome permission 'app.window.fullscreen.overrideEsc',
 * and called for both key down and key up events,
 * the ESC key remains usable within fullscreen Chrome app windows.
 */
hterm.Keyboard.prototype.preventChromeAppNonCtrlShiftDefault_ = function(e) {
  if (!window.chrome || !window.chrome.app || !window.chrome.app.window)
    return;
  if (!e.ctrlKey || !e.shiftKey)
    e.preventDefault();
};

hterm.Keyboard.prototype.onFocusOut_ = function(e) {
  this.altKeyPressed = 0;
};

hterm.Keyboard.prototype.onKeyUp_ = function(e) {
  if (e.keyCode == 18)
    this.altKeyPressed = this.altKeyPressed & ~(1 << (e.location - 1));

  if (e.keyCode == 27)
    this.preventChromeAppNonCtrlShiftDefault_(e);
};

/**
 * Handle onKeyDown events.
 */
hterm.Keyboard.prototype.onKeyDown_ = function(e) {
  if (e.keyCode == 18)
    this.altKeyPressed = this.altKeyPressed | (1 << (e.location - 1));

  if (e.keyCode == 27)
    this.preventChromeAppNonCtrlShiftDefault_(e);

  var keyDef = this.keyMap.keyDefs[e.keyCode];
  if (!keyDef) {
    // If this key hasn't been explicitly registered, fall back to the unknown
    // key mapping (keyCode == 0), and then automatically register it to avoid
    // any further warnings here.
    console.warn(`No definition for key ${e.key} (keyCode ${e.keyCode})`);
    keyDef = this.keyMap.keyDefs[0];
    this.keyMap.addKeyDef(e.keyCode, keyDef);
  }

  // The type of action we're going to use.
  var resolvedActionType = null;

  var self = this;
  function getAction(name) {
    // Get the key action for the given action name.  If the action is a
    // function, dispatch it.  If the action defers to the normal action,
    // resolve that instead.

    resolvedActionType = name;

    var action = keyDef[name];
    if (typeof action == 'function')
      action = action.apply(self.keyMap, [e, keyDef]);

    if (action === DEFAULT && name != 'normal')
      action = getAction('normal');

    return action;
  }

  // Note that we use the triple-equals ('===') operator to test equality for
  // these constants, in order to distinguish usage of the constant from usage
  // of a literal string that happens to contain the same bytes.
  var CANCEL = hterm.Keyboard.KeyActions.CANCEL;
  var DEFAULT = hterm.Keyboard.KeyActions.DEFAULT;
  var PASS = hterm.Keyboard.KeyActions.PASS;
  var STRIP = hterm.Keyboard.KeyActions.STRIP;

  var control = e.ctrlKey;
  var alt = this.altIsMeta ? false : e.altKey;
  var meta = this.altIsMeta ? (e.altKey || e.metaKey) : e.metaKey;

  // In the key-map, we surround the keyCap for non-printables in "[...]"
  var isPrintable = !(/^\[\w+\]$/.test(keyDef.keyCap));

  switch (this.altGrMode) {
    case 'ctrl-alt':
    if (isPrintable && control && alt) {
      // ctrl-alt-printable means altGr.  We clear out the control and
      // alt modifiers and wait to see the charCode in the keydown event.
      control = false;
      alt = false;
    }
    break;

    case 'right-alt':
    if (isPrintable && (this.terminal.keyboard.altKeyPressed & 2)) {
      control = false;
      alt = false;
    }
    break;

    case 'left-alt':
    if (isPrintable && (this.terminal.keyboard.altKeyPressed & 1)) {
      control = false;
      alt = false;
    }
    break;
  }

  var action;

  if (control) {
    action = getAction('control');
  } else if (alt) {
    action = getAction('alt');
  } else if (meta) {
    action = getAction('meta');
  } else {
    action = getAction('normal');
  }

  // If e.maskShiftKey was set (during getAction) it means the shift key is
  // already accounted for in the action, and we should not act on it any
  // further. This is currently only used for Ctrl-Shift-Tab, which should send
  // "CSI Z", not "CSI 1 ; 2 Z".
  var shift = !e.maskShiftKey && e.shiftKey;

  var keyDown = {
    keyCode: e.keyCode,
    shift: e.shiftKey, // not `var shift` from above.
    ctrl: control,
    alt: alt,
    meta: meta
  };

  var binding = this.bindings.getBinding(keyDown);

  if (binding) {
    // Clear out the modifier bits so we don't try to munge the sequence
    // further.
    shift = control = alt = meta = false;
    resolvedActionType = 'normal';
    action = binding.action;

    if (typeof action == 'function')
      action = action.call(this, this.terminal, keyDown);
  }

  if (alt && this.altSendsWhat == 'browser-key' && action == DEFAULT) {
    // When altSendsWhat is 'browser-key', we wait for the keypress event.
    // In keypress, the browser should have set the event.charCode to the
    // appropriate character.
    // TODO(rginda): Character compositions will need some black magic.
    action = PASS;
  }

  if (action === PASS || (action === DEFAULT && !(control || alt || meta))) {
    // If this key is supposed to be handled by the browser, or it is an
    // unmodified key with the default action, then exit this event handler.
    // If it's an unmodified key, it'll be handled in onKeyPress where we
    // can tell for sure which ASCII code to insert.
    //
    // This block needs to come before the STRIP test, otherwise we'll strip
    // the modifier and think it's ok to let the browser handle the keypress.
    // The browser won't know we're trying to ignore the modifiers and might
    // perform some default action.
    return;
  }

  if (action === STRIP) {
    alt = control = false;
    action = keyDef.normal;
    if (typeof action == 'function')
      action = action.apply(this.keyMap, [e, keyDef]);

    if (action == DEFAULT && keyDef.keyCap.length == 2)
      action = keyDef.keyCap.substr((shift ? 1 : 0), 1);
  }

  e.preventDefault();
  e.stopPropagation();

  if (action === CANCEL)
    return;

  if (action !== DEFAULT && typeof action != 'string') {
    console.warn('Invalid action: ' + JSON.stringify(action));
    return;
  }

  // Strip the modifier that is associated with the action, since we assume that
  // modifier has already been accounted for in the action.
  if (resolvedActionType == 'control') {
    control = false;
  } else if (resolvedActionType == 'alt') {
    alt = false;
  } else if (resolvedActionType == 'meta') {
    meta = false;
  }

  if (action.substr(0, 2) == '\x1b[' && (alt || control || shift || meta)) {
    // The action is an escape sequence that and it was triggered in the
    // presence of a keyboard modifier, we may need to alter the action to
    // include the modifier before sending it.

    // The math is funky but aligns w/xterm.
    let imod = 1;
    if (shift)
      imod += 1;
    if (alt)
      imod += 2;
    if (control)
      imod += 4;
    if (meta)
      imod += 8;
    let mod = ';' + imod;

    if (action.length == 3) {
      // Some of the CSI sequences have zero parameters unless modified.
      action = '\x1b[1' + mod + action.substr(2, 1);
    } else {
      // Others always have at least one parameter.
      action = action.substr(0, action.length - 1) + mod +
          action.substr(action.length - 1);
    }

  } else {
    if (action === DEFAULT) {
      action = keyDef.keyCap.substr((shift ? 1 : 0), 1);

      if (control) {
        var unshifted = keyDef.keyCap.substr(0, 1);
        var code = unshifted.charCodeAt(0);
        if (code >= 64 && code <= 95) {
          action = String.fromCharCode(code - 64);
        }
      }
    }

    if (alt && this.altSendsWhat == '8-bit' && action.length == 1) {
      var code = action.charCodeAt(0) + 128;
      action = String.fromCharCode(code);
    }

    // We respect alt/metaSendsEscape even if the keymap action was a literal
    // string.  Otherwise, every overridden alt/meta action would have to
    // check alt/metaSendsEscape.
    if ((alt && this.altSendsWhat == 'escape') ||
        (meta && this.metaSendsEscape)) {
      action = '\x1b' + action;
    }
  }

  this.terminal.onVTKeystroke(action);
};
// SOURCE FILE: hterm/js/hterm_keyboard_bindings.js
// Copyright (c) 2015 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

/**
 * A mapping from hterm.Keyboard.KeyPattern to an action.
 *
 * TODO(rginda): For now this bindings code is only used for user overrides.
 * hterm.Keyboard.KeyMap still handles all of the built-in key mappings.
 * It'd be nice if we migrated that over to be hterm.Keyboard.Bindings based.
 */
hterm.Keyboard.Bindings = function() {
  this.bindings_ = {};
};

/**
 * Remove all bindings.
 */
hterm.Keyboard.Bindings.prototype.clear = function () {
  this.bindings_ = {};
};

/**
 * Add a new binding.
 *
 * Internal API that assumes parsed objects as inputs.
 * See the public addBinding for more details.
 *
 * @param {hterm.Keyboard.KeyPattern} keyPattern
 * @param {string|function|hterm.Keyboard.KeyAction} action
 */
hterm.Keyboard.Bindings.prototype.addBinding_ = function(keyPattern, action) {
  var binding = null;
  var list = this.bindings_[keyPattern.keyCode];
  if (list) {
    for (var i = 0; i < list.length; i++) {
      if (list[i].keyPattern.matchKeyPattern(keyPattern)) {
        binding = list[i];
        break;
      }
    }
  }

  if (binding) {
    binding.action = action;
  } else {
    binding = {keyPattern: keyPattern, action: action};

    if (!list) {
      this.bindings_[keyPattern.keyCode] = [binding];
    } else {
      this.bindings_[keyPattern.keyCode].push(binding);

      list.sort(function(a, b) {
        return hterm.Keyboard.KeyPattern.sortCompare(
            a.keyPattern, b.keyPattern);
      });
    }
  }
};

/**
 * Add a new binding.
 *
 * If a binding for the keyPattern already exists it will be overridden.
 *
 * More specific keyPatterns take precedence over those with wildcards.  Given
 * bindings for "Ctrl-A" and "Ctrl-*-A", and a "Ctrl-A" keydown, the "Ctrl-A"
 * binding will match even if "Ctrl-*-A" was created last.
 *
 * If action is a string, it will be passed through hterm.Parser.parseKeyAction.
 *
 * For example:
 *   // Will replace Ctrl-P keystrokes with the string "hiya!".
 *   addBinding('Ctrl-P', "'hiya!'");
 *   // Will cancel the keystroke entirely (make it do nothing).
 *   addBinding('Alt-D', hterm.Keyboard.KeyActions.CANCEL);
 *   // Will execute the code and return the action.
 *   addBinding('Ctrl-T', function() {
 *     console.log('Got a T!');
 *     return hterm.Keyboard.KeyActions.PASS;
 *   });
 *
 * @param {string|hterm.Keyboard.KeyPattern} keyPattern
 * @param {string|function|hterm.Keyboard.KeyAction} action
 */
hterm.Keyboard.Bindings.prototype.addBinding = function(key, action) {
  // If we're given a hterm.Keyboard.KeyPattern object, pass it down.
  if (typeof key != 'string') {
    this.addBinding_(key, action);
    return;
  }

  // Here we treat key as a string.
  var p = new hterm.Parser();

  p.reset(key);
  var sequence;

  try {
    sequence = p.parseKeySequence();
  } catch (ex) {
    console.error(ex);
    return;
  }

  if (!p.isComplete()) {
    console.error(p.error('Expected end of sequence: ' + sequence));
    return;
  }

  // If action is a string, parse it.  Otherwise assume it's callable.
  if (typeof action == 'string') {
    p.reset(action);
    try {
      action = p.parseKeyAction();
    } catch (ex) {
      console.error(ex);
      return;
    }
  }

  if (!p.isComplete()) {
    console.error(p.error('Expected end of sequence: ' + sequence));
    return;
  }

  this.addBinding_(new hterm.Keyboard.KeyPattern(sequence), action);
};

/**
 * Add multiple bindings at a time using a map of {string: string, ...}
 *
 * This uses hterm.Parser to parse the maps key into KeyPatterns, and the
 * map values into {string|function|KeyAction}.
 *
 * For example:
 *  {
 *    // Will replace Ctrl-P keystrokes with the string "hiya!".
 *    'Ctrl-P': "'hiya!'",
 *    // Will cancel the keystroke entirely (make it do nothing).
 *    'Alt-D': hterm.Keyboard.KeyActions.CANCEL,
 *  }
 *
 * @param {Object} map
 */
hterm.Keyboard.Bindings.prototype.addBindings = function(map) {
  for (var key in map) {
    this.addBinding(key, map[key]);
  }
};

/**
 * Return the binding that is the best match for the given keyDown record,
 * or null if there is no match.
 *
 * @param {Object} keyDown An object with a keyCode property and zero or
 *   more boolean properties representing key modifiers.  These property names
 *   must match those defined in hterm.Keyboard.KeyPattern.modifiers.
 */
hterm.Keyboard.Bindings.prototype.getBinding = function(keyDown) {
  var list = this.bindings_[keyDown.keyCode];
  if (!list)
    return null;

  for (var i = 0; i < list.length; i++) {
    var binding = list[i];
    if (binding.keyPattern.matchKeyDown(keyDown))
      return binding;
  }

  return null;
};
// SOURCE FILE: hterm/js/hterm_keyboard_keymap.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

lib.rtdep('hterm.Keyboard.KeyActions');

/**
 * The default key map for hterm.
 *
 * Contains a mapping of keyCodes to keyDefs (aka key definitions).  The key
 * definition tells the hterm.Keyboard class how to handle keycodes.
 *
 * This should work for most cases, as the printable characters get handled
 * in the keypress event.  In that case, even if the keycap is wrong in the
 * key map, the correct character should be sent.
 *
 * Different layouts, such as Dvorak should work with this keymap, as those
 * layouts typically move keycodes around on the keyboard without disturbing
 * the actual keycaps.
 *
 * There may be issues with control keys on non-US keyboards or with keyboards
 * that very significantly from the expectations here, in which case we may
 * have to invent new key maps.
 *
 * The sequences defined in this key map come from [XTERM] as referenced in
 * vt.js, starting with the section titled "Alt and Meta Keys".
 */
hterm.Keyboard.KeyMap = function(keyboard) {
  this.keyboard = keyboard;
  this.keyDefs = {};
  this.reset();
};

/**
 * Add a single key definition.
 *
 * The definition is an object containing the following fields: 'keyCap',
 * 'normal', 'control', 'alt', and 'meta'.
 *
 *  - keyCap is a string identifying the key on the keyboard.  For printable
 *    keys, the key cap should be exactly two characters, starting with the
 *    unshifted version.  For example, 'aA', 'bB', '1!' and '=+'.  For
 *    non-printable the key cap should be surrounded in square braces, as in
 *    '[INS]', '[LEFT]'.  By convention, non-printable keycaps are in uppercase
 *    but this is not a strict requirement.
 *
 *  - Normal is the action that should be performed when the key is pressed
 *    in the absence of any modifier.  See below for the supported actions.
 *
 *  - Control is the action that should be performed when the key is pressed
 *    along with the control modifier.  See below for the supported actions.
 *
 *  - Alt is the action that should be performed when the key is pressed
 *    along with the alt modifier.  See below for the supported actions.
 *
 *  - Meta is the action that should be performed when the key is pressed
 *    along with the meta modifier.  See below for the supported actions.
 *
 * Actions can be one of the hterm.Keyboard.KeyActions as documented below,
 * a literal string, or an array.  If the action is a literal string then
 * the string is sent directly to the host.  If the action is an array it
 * is taken to be an escape sequence that may be altered by modifier keys.
 * The second-to-last element of the array will be overwritten with the
 * state of the modifier keys, as specified in the final table of "PC-Style
 * Function Keys" from [XTERM].
 */
hterm.Keyboard.KeyMap.prototype.addKeyDef = function(keyCode, def) {
  if (keyCode in this.keyDefs)
    console.warn('Duplicate keyCode: ' + keyCode);

  this.keyDefs[keyCode] = def;
};

/**
 * Add multiple key definitions in a single call.
 *
 * This function takes the key definitions as variable argument list.  Each
 * argument is the key definition specified as an array.
 *
 * (If the function took everything as one big hash we couldn't detect
 * duplicates, and there would be a lot more typing involved.)
 *
 * Each key definition should have 6 elements: (keyCode, keyCap, normal action,
 * control action, alt action and meta action).  See KeyMap.addKeyDef for the
 * meaning of these elements.
 */
hterm.Keyboard.KeyMap.prototype.addKeyDefs = function(var_args) {
  for (var i = 0; i < arguments.length; i++) {
    this.addKeyDef(arguments[i][0],
                   { keyCap: arguments[i][1],
                     normal: arguments[i][2],
                     control: arguments[i][3],
                     alt: arguments[i][4],
                     meta: arguments[i][5]
                   });
  }
};

/**
 * Set up the default state for this keymap.
 */
hterm.Keyboard.KeyMap.prototype.reset = function() {
  this.keyDefs = {};

  var self = this;

  // This function is used by the "macro" functions below.  It makes it
  // possible to use the call() macro as an argument to any other macro.
  function resolve(action, e, k) {
    if (typeof action == 'function')
      return action.apply(self, [e, k]);

    return action;
  }

  // If not application keypad a, else b.  The keys that care about
  // application keypad ignore it when the key is modified.
  function ak(a, b) {
    return function(e, k) {
      var action = (e.shiftKey || e.ctrlKey || e.altKey || e.metaKey ||
                    !self.keyboard.applicationKeypad) ? a : b;
      return resolve(action, e, k);
    };
  }

  // If mod or not application cursor a, else b.  The keys that care about
  // application cursor ignore it when the key is modified.
  function ac(a, b) {
    return function(e, k) {
      var action = (e.shiftKey || e.ctrlKey || e.altKey || e.metaKey ||
                    !self.keyboard.applicationCursor) ? a : b;
      return resolve(action, e, k);
    };
  }

  // If not backspace-sends-backspace keypad a, else b.
  function bs(a, b) {
    return function(e, k) {
      var action = !self.keyboard.backspaceSendsBackspace ? a : b;
      return resolve(action, e, k);
    };
  }

  // If not e.shiftKey a, else b.
  function sh(a, b) {
    return function(e, k) {
      var action = !e.shiftKey ? a : b;
      e.maskShiftKey = true;
      return resolve(action, e, k);
    };
  }

  // If not e.altKey a, else b.
  function alt(a, b) {
    return function(e, k) {
      var action = !e.altKey ? a : b;
      return resolve(action, e, k);
    };
  }

  // If no modifiers a, else b.
  function mod(a, b) {
    return function(e, k) {
      var action = !(e.shiftKey || e.ctrlKey || e.altKey || e.metaKey) ? a : b;
      return resolve(action, e, k);
    };
  }

  // Compute a control character for a given character.
  function ctl(ch) { return String.fromCharCode(ch.charCodeAt(0) - 64); }

  // Call a method on the keymap instance.
  function c(m) { return function(e, k) { return this[m](e, k); }; }

  // Ignore if not trapping media keys.
  function med(fn) {
    return function(e, k) {
      if (!self.keyboard.mediaKeysAreFKeys) {
        // Block Back, Forward, and Reload keys to avoid navigating away from
        // the current page.
        return (e.keyCode == 166 || e.keyCode == 167 || e.keyCode == 168) ?
            hterm.Keyboard.KeyActions.CANCEL :
            hterm.Keyboard.KeyActions.PASS;
      }
      return resolve(fn, e, k);
    };
  }

  // Browser-specific differences.
  if (window.navigator && navigator.userAgent) {
    if (navigator.userAgent.includes('Firefox')) {
      // Firefox defines some keys uniquely.  No other browser defines these is
      // this way.  Some even conflict.  The keyCode field isn't well documented
      // as it isn't standardized.  At some point we should switch to "key".
      // https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/keyCode
      // http://unixpapa.com/js/key.html
      var keycapMute = 181;   // Mute
      var keycapVolDn = 182;  // Volume Down
      var keycapVolUp = 183;  // Volume Up
      var keycapSC = 59;      // ;:
      var keycapEP = 61;      // =+
      var keycapMU = 173;     // -_

      this.addKeyDefs(
        // Firefox Italian +*.
        [171, '+*', DEFAULT, c('onPlusMinusZero_'), DEFAULT, c('onPlusMinusZero_')]
      );
    } else {
      // All other browsers use these mappings.
      var keycapMute = 173;   // Mute
      var keycapVolDn = 174;  // Volume Down
      var keycapVolUp = 175;  // Volume Up
      var keycapSC = 186;     // ;:
      var keycapEP = 187;     // =+
      var keycapMU = 189;     // -_
    }
  }

  var ESC = '\x1b';
  var CSI = '\x1b[';
  var SS3 = '\x1bO';

  var CANCEL = hterm.Keyboard.KeyActions.CANCEL;
  var DEFAULT = hterm.Keyboard.KeyActions.DEFAULT;
  var PASS = hterm.Keyboard.KeyActions.PASS;
  var STRIP = hterm.Keyboard.KeyActions.STRIP;

  this.addKeyDefs(
    // These fields are: [keycode, keycap, normal, control, alt, meta]

    // The browser sends the keycode 0 for some keys.  We'll just assume it's
    // going to do the right thing by default for those keys.
    [0,   '[UNKNOWN]', PASS, PASS, PASS, PASS],

    // First row.
    // These bindings match xterm for lack of a better standard.  The emitted
    // values might look like they're skipping values, but it's what xterm does.
    // https://invisible-island.net/xterm/ctlseqs/ctlseqs.html#h2-PC-Style-Function-Keys
    [27,  '[ESC]', ESC,                       DEFAULT, DEFAULT,     DEFAULT],
    [112, '[F1]',  mod(SS3 + 'P', CSI + 'P'), DEFAULT, CSI + "23~", DEFAULT],
    [113, '[F2]',  mod(SS3 + 'Q', CSI + 'Q'), DEFAULT, CSI + "24~", DEFAULT],
    [114, '[F3]',  mod(SS3 + 'R', CSI + 'R'), DEFAULT, CSI + "25~", DEFAULT],
    [115, '[F4]',  mod(SS3 + 'S', CSI + 'S'), DEFAULT, CSI + "26~", DEFAULT],
    [116, '[F5]',  CSI + '15~',               DEFAULT, CSI + "28~", DEFAULT],
    [117, '[F6]',  CSI + '17~',               DEFAULT, CSI + "29~", DEFAULT],
    [118, '[F7]',  CSI + '18~',               DEFAULT, CSI + "31~", DEFAULT],
    [119, '[F8]',  CSI + '19~',               DEFAULT, CSI + "32~", DEFAULT],
    [120, '[F9]',  CSI + '20~',               DEFAULT, CSI + "33~", DEFAULT],
    [121, '[F10]', CSI + '21~',               DEFAULT, CSI + "34~", DEFAULT],
    [122, '[F11]', c('onF11_'),               DEFAULT, CSI + "42~", DEFAULT],
    [123, '[F12]', CSI + '24~',               DEFAULT, CSI + "43~", DEFAULT],

    // Second row.
    [192, '`~', DEFAULT, sh(ctl('@'), ctl('^')),     DEFAULT,           PASS],
    [49,  '1!', DEFAULT, c('onCtrlNum_'),    c('onAltNum_'), c('onMetaNum_')],
    [50,  '2@', DEFAULT, c('onCtrlNum_'),    c('onAltNum_'), c('onMetaNum_')],
    [51,  '3#', DEFAULT, c('onCtrlNum_'),    c('onAltNum_'), c('onMetaNum_')],
    [52,  '4$', DEFAULT, c('onCtrlNum_'),    c('onAltNum_'), c('onMetaNum_')],
    [53,  '5%', DEFAULT, c('onCtrlNum_'),    c('onAltNum_'), c('onMetaNum_')],
    [54,  '6^', DEFAULT, c('onCtrlNum_'),    c('onAltNum_'), c('onMetaNum_')],
    [55,  '7&', DEFAULT, c('onCtrlNum_'),    c('onAltNum_'), c('onMetaNum_')],
    [56,  '8*', DEFAULT, c('onCtrlNum_'),    c('onAltNum_'), c('onMetaNum_')],
    [57,  '9(', DEFAULT, c('onCtrlNum_'),    c('onAltNum_'), c('onMetaNum_')],
    [48,  '0)', DEFAULT, c('onPlusMinusZero_'),c('onAltNum_'),c('onPlusMinusZero_')],
    [keycapMU, '-_', DEFAULT, c('onPlusMinusZero_'), DEFAULT, c('onPlusMinusZero_')],
    [keycapEP, '=+', DEFAULT, c('onPlusMinusZero_'), DEFAULT, c('onPlusMinusZero_')],

    [8,   '[BKSP]', bs('\x7f', '\b'), bs('\b', '\x7f'), DEFAULT,     DEFAULT],

    // Third row.
    [9,   '[TAB]', sh('\t', CSI + 'Z'), STRIP,     PASS,    DEFAULT],
    [81,  'qQ',    DEFAULT,             ctl('Q'),  DEFAULT, DEFAULT],
    [87,  'wW',    DEFAULT,             ctl('W'),  DEFAULT, DEFAULT],
    [69,  'eE',    DEFAULT,             ctl('E'),  DEFAULT, DEFAULT],
    [82,  'rR',    DEFAULT,             ctl('R'),  DEFAULT, DEFAULT],
    [84,  'tT',    DEFAULT,             ctl('T'),  DEFAULT, DEFAULT],
    [89,  'yY',    DEFAULT,             ctl('Y'),  DEFAULT, DEFAULT],
    [85,  'uU',    DEFAULT,             ctl('U'),  DEFAULT, DEFAULT],
    [73,  'iI',    DEFAULT,             ctl('I'),  DEFAULT, DEFAULT],
    [79,  'oO',    DEFAULT,             ctl('O'),  DEFAULT, DEFAULT],
    [80,  'pP',    DEFAULT,             ctl('P'),  DEFAULT, DEFAULT],
    [219, '[{',    DEFAULT,             ctl('['),  DEFAULT, DEFAULT],
    [221, ']}',    DEFAULT,             ctl(']'),  DEFAULT, DEFAULT],
    [220, '\\|',   DEFAULT,             ctl('\\'), DEFAULT, DEFAULT],

    // Fourth row. (We let Ctrl-Shift-J pass for Chrome DevTools.)
    [20,  '[CAPS]',  PASS,    PASS,                           PASS,    DEFAULT],
    [65,  'aA',      DEFAULT, ctl('A'),                       DEFAULT, DEFAULT],
    [83,  'sS',      DEFAULT, ctl('S'),                       DEFAULT, DEFAULT],
    [68,  'dD',      DEFAULT, ctl('D'),                       DEFAULT, DEFAULT],
    [70,  'fF',      DEFAULT, ctl('F'),                       DEFAULT, DEFAULT],
    [71,  'gG',      DEFAULT, ctl('G'),                       DEFAULT, DEFAULT],
    [72,  'hH',      DEFAULT, ctl('H'),                       DEFAULT, DEFAULT],
    [74,  'jJ',      DEFAULT, sh(ctl('J'), PASS),             DEFAULT, DEFAULT],
    [75,  'kK',      DEFAULT, sh(ctl('K'), c('onClear_')),    DEFAULT, DEFAULT],
    [76,  'lL',      DEFAULT, sh(ctl('L'), PASS),             DEFAULT, DEFAULT],
    [keycapSC, ';:', DEFAULT, STRIP,                          DEFAULT, DEFAULT],
    [222, '\'"',     DEFAULT, STRIP,                          DEFAULT, DEFAULT],
    [13,  '[ENTER]', '\r',    CANCEL,                         CANCEL,  DEFAULT],

    // Fifth row.  This includes the copy/paste shortcuts.  On some
    // platforms it's Ctrl-C/V, on others it's Meta-C/V.  We assume either
    // Ctrl-C/Meta-C should pass to the browser when there is a selection,
    // and Ctrl-Shift-V/Meta-*-V should always pass to the browser (since
    // these seem to be recognized as paste too).
    [16,  '[SHIFT]', PASS, PASS,                   PASS,    DEFAULT],
    [90,  'zZ',   DEFAULT, ctl('Z'),               DEFAULT, DEFAULT],
    [88,  'xX',   DEFAULT, ctl('X'),               DEFAULT, DEFAULT],
    [67,  'cC',   DEFAULT, c('onCtrlC_'),          DEFAULT, c('onMetaC_')],
    [86,  'vV',   DEFAULT, c('onCtrlV_'),          DEFAULT, c('onMetaV_')],
    [66,  'bB',   DEFAULT, sh(ctl('B'), PASS),     DEFAULT, sh(DEFAULT, PASS)],
    [78,  'nN',   DEFAULT, c('onCtrlN_'),          DEFAULT, c('onMetaN_')],
    [77,  'mM',   DEFAULT, ctl('M'),               DEFAULT, DEFAULT],
    [188, ',<',   DEFAULT, alt(STRIP, PASS),       DEFAULT, DEFAULT],
    [190, '.>',   DEFAULT, alt(STRIP, PASS),       DEFAULT, DEFAULT],
    [191, '/?',   DEFAULT, sh(ctl('_'), ctl('?')), DEFAULT, DEFAULT],

    // Sixth and final row.
    [17,  '[CTRL]',  PASS,    PASS,     PASS,    PASS],
    [18,  '[ALT]',   PASS,    PASS,     PASS,    PASS],
    [91,  '[LAPL]',  PASS,    PASS,     PASS,    PASS],
    [32,  ' ',       DEFAULT, ctl('@'), DEFAULT, DEFAULT],
    [92,  '[RAPL]',  PASS,    PASS,     PASS,    PASS],
    [93,  '[RMENU]', PASS,    PASS,     PASS,    PASS],

    // These things.
    [42,  '[PRTSCR]', PASS, PASS, PASS, PASS],
    [145, '[SCRLK]',  PASS, PASS, PASS, PASS],
    [19,  '[BREAK]',  PASS, PASS, PASS, PASS],

    // The block of six keys above the arrows.
    [45,  '[INSERT]', c('onKeyInsert_'),   DEFAULT, DEFAULT, DEFAULT],
    [36,  '[HOME]',   c('onKeyHome_'),     DEFAULT, DEFAULT, DEFAULT],
    [33,  '[PGUP]',   c('onKeyPageUp_'),   DEFAULT, DEFAULT, DEFAULT],
    [46,  '[DEL]',    c('onKeyDel_'),      DEFAULT, DEFAULT, DEFAULT],
    [35,  '[END]',    c('onKeyEnd_'),      DEFAULT, DEFAULT, DEFAULT],
    [34,  '[PGDOWN]', c('onKeyPageDown_'), DEFAULT, DEFAULT, DEFAULT],

    // Arrow keys.  When unmodified they respect the application cursor state,
    // otherwise they always send the CSI codes.
    [38, '[UP]',    c('onKeyArrowUp_'), DEFAULT, DEFAULT, DEFAULT],
    [40, '[DOWN]',  c('onKeyArrowDown_'), DEFAULT, DEFAULT, DEFAULT],
    [39, '[RIGHT]', ac(CSI + 'C', SS3 + 'C'), DEFAULT, DEFAULT, DEFAULT],
    [37, '[LEFT]',  ac(CSI + 'D', SS3 + 'D'), DEFAULT, DEFAULT, DEFAULT],

    [144, '[NUMLOCK]', PASS, PASS, PASS, PASS],

    // On Apple keyboards, the NumLock key is a Clear key.  It also tends to be
    // what KP5 sends when numlock is off.  Not clear if we could do anything
    // useful with it, so just pass it along.
    [12, '[CLEAR]', PASS, PASS, PASS, PASS],

    // With numlock off, the keypad generates the same key codes as the arrows
    // and 'block of six' for some keys, and null key codes for the rest.

    // Keypad with numlock on generates unique key codes...
    [96,  '[KP0]', DEFAULT, DEFAULT, DEFAULT, DEFAULT],
    [97,  '[KP1]', DEFAULT, DEFAULT, DEFAULT, DEFAULT],
    [98,  '[KP2]', DEFAULT, DEFAULT, DEFAULT, DEFAULT],
    [99,  '[KP3]', DEFAULT, DEFAULT, DEFAULT, DEFAULT],
    [100, '[KP4]', DEFAULT, DEFAULT, DEFAULT, DEFAULT],
    [101, '[KP5]', DEFAULT, DEFAULT, DEFAULT, DEFAULT],
    [102, '[KP6]', DEFAULT, DEFAULT, DEFAULT, DEFAULT],
    [103, '[KP7]', DEFAULT, DEFAULT, DEFAULT, DEFAULT],
    [104, '[KP8]', DEFAULT, DEFAULT, DEFAULT, DEFAULT],
    [105, '[KP9]', DEFAULT, DEFAULT, DEFAULT, DEFAULT],
    [107, '[KP+]', DEFAULT, c('onPlusMinusZero_'), DEFAULT, c('onPlusMinusZero_')],
    [109, '[KP-]', DEFAULT, c('onPlusMinusZero_'), DEFAULT, c('onPlusMinusZero_')],
    [106, '[KP*]', DEFAULT, DEFAULT, DEFAULT, DEFAULT],
    [111, '[KP/]', DEFAULT, DEFAULT, DEFAULT, DEFAULT],
    [110, '[KP.]', DEFAULT, DEFAULT, DEFAULT, DEFAULT]
  );

  // OS-specific differences.
  if (hterm.os == 'cros') {
    this.addKeyDefs(
      // Chrome OS keyboard top row.  The media-keys-are-fkeys preference allows
      // users to make these always behave as function keys (see those bindings
      // above for more details).
      [166, '[BACK]',   med(mod(SS3+'P', CSI+'P')), DEFAULT, CSI+'23~', DEFAULT],  // F1
      [167, '[FWD]',    med(mod(SS3+'Q', CSI+'Q')), DEFAULT, CSI+'24~', DEFAULT],  // F2
      [168, '[RELOAD]', med(mod(SS3+'R', CSI+'R')), DEFAULT, CSI+'25~', DEFAULT],  // F3
      [183, '[FSCR]',   med(mod(SS3+'S', CSI+'S')), DEFAULT, CSI+'26~', DEFAULT],  // F4
      [182, '[WINS]',   med(CSI + '15~'),           DEFAULT, CSI+'28~', DEFAULT],  // F5
      [216, '[BRIT-]',  med(CSI + '17~'),           DEFAULT, CSI+'29~', DEFAULT],  // F6
      [217, '[BRIT+]',  med(CSI + '18~'),           DEFAULT, CSI+'31~', DEFAULT],  // F7
      [173, '[MUTE]',   med(CSI + '19~'),           DEFAULT, CSI+'32~', DEFAULT],  // F8
      [174, '[VOL-]',   med(CSI + '20~'),           DEFAULT, CSI+'33~', DEFAULT],  // F9
      [175, '[VOL+]',   med(CSI + '21~'),           DEFAULT, CSI+'34~', DEFAULT],  // F10

      // We could make this into F11, but it'd be a bit weird.  Chrome allows us
      // to see this and react, but it doesn't actually allow us to block or
      // cancel it, so it makes the screen flash/lock still.
      [152, '[POWER]',  DEFAULT, DEFAULT, DEFAULT, DEFAULT],

      // The Pixelbook has a slightly different layout.  This means half the keys
      // above are off by one.  https://crbug.com/807513
      [179, '[PLAY]',   med(CSI + '18~'),           DEFAULT, CSI + '31~', DEFAULT], // F7
      // The settings / hamburgers / three hot dogs / menu / whatever-it's-called.
      [154, '[DOGS]',   med(CSI + '23~'),           DEFAULT, CSI + '42~', DEFAULT], // F11

      // We don't use this for anything, but keep it from popping up by default.
      [153, '[ASSIST]', DEFAULT, DEFAULT, DEFAULT, DEFAULT]
    );
  }
};

/**
 * Either allow the paste or send a key sequence.
 */
hterm.Keyboard.KeyMap.prototype.onKeyInsert_ = function(e) {
  if (this.keyboard.shiftInsertPaste && e.shiftKey)
    return hterm.Keyboard.KeyActions.PASS;

  return '\x1b[2~';
};

/**
 * Either scroll the scrollback buffer or send a key sequence.
 */
hterm.Keyboard.KeyMap.prototype.onKeyHome_ = function(e) {
  if (!this.keyboard.homeKeysScroll ^ e.shiftKey) {
    if ((e.altey || e.ctrlKey || e.shiftKey) ||
        !this.keyboard.applicationCursor) {
      return '\x1b[H';
    }

    return '\x1bOH';
  }

  this.keyboard.terminal.scrollHome();
  return hterm.Keyboard.KeyActions.CANCEL;
};

/**
 * Either scroll the scrollback buffer or send a key sequence.
 */
hterm.Keyboard.KeyMap.prototype.onKeyEnd_ = function(e) {
  if (!this.keyboard.homeKeysScroll ^ e.shiftKey) {
    if ((e.altKey || e.ctrlKey || e.shiftKey) ||
        !this.keyboard.applicationCursor) {
      return '\x1b[F';
    }

    return '\x1bOF';
  }

  this.keyboard.terminal.scrollEnd();
  return hterm.Keyboard.KeyActions.CANCEL;
};

/**
 * Either scroll the scrollback buffer or send a key sequence.
 */
hterm.Keyboard.KeyMap.prototype.onKeyPageUp_ = function(e) {
  if (!this.keyboard.pageKeysScroll ^ e.shiftKey)
    return '\x1b[5~';

  this.keyboard.terminal.scrollPageUp();
  return hterm.Keyboard.KeyActions.CANCEL;
};

/**
 * Either send a true DEL, or sub in meta-backspace.
 *
 * On Chrome OS, if we know the alt key is down, but we get a DEL event that
 * claims that the alt key is not pressed, we know the DEL was a synthetic
 * one from a user that hit alt-backspace. Based on a user pref, we can sub
 * in meta-backspace in this case.
 */
hterm.Keyboard.KeyMap.prototype.onKeyDel_ = function(e) {
  if (this.keyboard.altBackspaceIsMetaBackspace &&
      this.keyboard.altKeyPressed && !e.altKey)
    return '\x1b\x7f';
  return '\x1b[3~';
};

/**
 * Either scroll the scrollback buffer or send a key sequence.
 */
hterm.Keyboard.KeyMap.prototype.onKeyPageDown_ = function(e) {
  if (!this.keyboard.pageKeysScroll ^ e.shiftKey)
    return '\x1b[6~';

  this.keyboard.terminal.scrollPageDown();
  return hterm.Keyboard.KeyActions.CANCEL;
};

/**
 * Either scroll the scrollback buffer or send a key sequence.
 */
hterm.Keyboard.KeyMap.prototype.onKeyArrowUp_ = function(e) {
  if (!this.keyboard.applicationCursor && e.shiftKey) {
    this.keyboard.terminal.scrollLineUp();
    return hterm.Keyboard.KeyActions.CANCEL;
  }

  return (e.shiftKey || e.ctrlKey || e.altKey || e.metaKey ||
          !this.keyboard.applicationCursor) ? '\x1b[A' : '\x1bOA';
};

/**
 * Either scroll the scrollback buffer or send a key sequence.
 */
hterm.Keyboard.KeyMap.prototype.onKeyArrowDown_ = function(e) {
  if (!this.keyboard.applicationCursor && e.shiftKey) {
    this.keyboard.terminal.scrollLineDown();
    return hterm.Keyboard.KeyActions.CANCEL;
  }

  return (e.shiftKey || e.ctrlKey || e.altKey || e.metaKey ||
          !this.keyboard.applicationCursor) ? '\x1b[B' : '\x1bOB';
};

/**
 * Clear the primary/alternate screens and the scrollback buffer.
 */
hterm.Keyboard.KeyMap.prototype.onClear_ = function(e, keyDef) {
  this.keyboard.terminal.wipeContents();
  return hterm.Keyboard.KeyActions.CANCEL;
};

/**
 * Handle F11 behavior (fullscreen) when not in a window.
 *
 * It would be nice to use the Fullscreen API, but the UX is slightly different
 * a bad way: the Escape key is automatically registered for exiting.  If we let
 * the browser handle F11 directly though, we still get to capture Escape.
 */
hterm.Keyboard.KeyMap.prototype.onF11_ = function(e, keyDef) {
  if (hterm.windowType != 'popup')
    return hterm.Keyboard.KeyActions.PASS;
  else
    return '\x1b[23~';
};

/**
 * Either pass Ctrl-1..9 to the browser or send them to the host.
 *
 * Note that Ctrl-1 and Ctrl-9 don't actually have special sequences mapped
 * to them in xterm or gnome-terminal.  The range is really Ctrl-2..8, but
 * we handle 1..9 since Chrome treats the whole range special.
 */
hterm.Keyboard.KeyMap.prototype.onCtrlNum_ = function(e, keyDef) {
  // Compute a control character for a given character.
  function ctl(ch) { return String.fromCharCode(ch.charCodeAt(0) - 64); }

  if (this.keyboard.terminal.passCtrlNumber && !e.shiftKey)
    return hterm.Keyboard.KeyActions.PASS;

  switch (keyDef.keyCap.substr(0, 1)) {
    case '1': return '1';
    case '2': return ctl('@');
    case '3': return ctl('[');
    case '4': return ctl('\\');
    case '5': return ctl(']');
    case '6': return ctl('^');
    case '7': return ctl('_');
    case '8': return '\x7f';
    case '9': return '9';
  }
};

/**
 * Either pass Alt-1..9 to the browser or send them to the host.
 */
hterm.Keyboard.KeyMap.prototype.onAltNum_ = function(e, keyDef) {
  if (this.keyboard.terminal.passAltNumber && !e.shiftKey)
    return hterm.Keyboard.KeyActions.PASS;

  return hterm.Keyboard.KeyActions.DEFAULT;
};

/**
 * Either pass Meta-1..9 to the browser or send them to the host.
 */
hterm.Keyboard.KeyMap.prototype.onMetaNum_ = function(e, keyDef) {
  if (this.keyboard.terminal.passMetaNumber && !e.shiftKey)
    return hterm.Keyboard.KeyActions.PASS;

  return hterm.Keyboard.KeyActions.DEFAULT;
};

/**
 * Either send a ^C or interpret the keystroke as a copy command.
 */
hterm.Keyboard.KeyMap.prototype.onCtrlC_ = function(e, keyDef) {
  var selection = this.keyboard.terminal.getDocument().getSelection();

  if (!selection.isCollapsed) {
    if (this.keyboard.ctrlCCopy && !e.shiftKey) {
      // Ctrl-C should copy if there is a selection, send ^C otherwise.
      // Perform the copy by letting the browser handle Ctrl-C.  On most
      // browsers, this is the *only* way to place text on the clipboard from
      // the 'drive-by' web.
      if (this.keyboard.terminal.clearSelectionAfterCopy) {
        setTimeout(selection.collapseToEnd.bind(selection), 50);
      }
      return hterm.Keyboard.KeyActions.PASS;
    }

    if (!this.keyboard.ctrlCCopy && e.shiftKey) {
      // Ctrl-Shift-C should copy if there is a selection, send ^C otherwise.
      // Perform the copy manually.  This only works in situations where
      // document.execCommand('copy') is allowed.
      if (this.keyboard.terminal.clearSelectionAfterCopy) {
        setTimeout(selection.collapseToEnd.bind(selection), 50);
      }
      this.keyboard.terminal.copySelectionToClipboard();
      return hterm.Keyboard.KeyActions.CANCEL;
    }
  }

  return '\x03';
};

/**
 * Either send a ^N or open a new window to the same location.
 */
hterm.Keyboard.KeyMap.prototype.onCtrlN_ = function(e, keyDef) {
  if (e.shiftKey) {
    lib.f.openWindow(document.location.href, '',
                     'chrome=no,close=yes,resize=yes,scrollbars=yes,' +
                     'minimizable=yes,width=' + window.innerWidth +
                     ',height=' + window.innerHeight);
    return hterm.Keyboard.KeyActions.CANCEL;
  }

  return '\x0e';
};

/**
 * Either send a ^V or issue a paste command.
 *
 * The default behavior is to paste if the user presses Ctrl-Shift-V, and send
 * a ^V if the user presses Ctrl-V. This can be flipped with the
 * 'ctrl-v-paste' preference.
 *
 */
hterm.Keyboard.KeyMap.prototype.onCtrlV_ = function(e, keyDef) {
  if ((!e.shiftKey && this.keyboard.ctrlVPaste) ||
      (e.shiftKey && !this.keyboard.ctrlVPaste)) {
    // We try to do the pasting ourselves as not all browsers/OSs bind Ctrl-V to
    // pasting.  Notably, on macOS, Ctrl-V/Ctrl-Shift-V do nothing.
    // However, this might run into web restrictions, so if it fails, we still
    // fallback to the letting the native behavior (hopefully) save us.
    if (this.keyboard.terminal.paste())
      return hterm.Keyboard.KeyActions.CANCEL;
    else
      return hterm.Keyboard.KeyActions.PASS;
  }

  return '\x16';
};

/**
 * Either the default action or open a new window to the same location.
 */
hterm.Keyboard.KeyMap.prototype.onMetaN_ = function(e, keyDef) {
  if (e.shiftKey) {
    lib.f.openWindow(document.location.href, '',
                     'chrome=no,close=yes,resize=yes,scrollbars=yes,' +
                     'minimizable=yes,width=' + window.outerWidth +
                     ',height=' + window.outerHeight);
    return hterm.Keyboard.KeyActions.CANCEL;
  }

  return hterm.Keyboard.KeyActions.DEFAULT;
};

/**
 * Either send a Meta-C or allow the browser to interpret the keystroke as a
 * copy command.
 *
 * If there is no selection, or if the user presses Meta-Shift-C, then we'll
 * transmit an '\x1b' (if metaSendsEscape is on) followed by 'c' or 'C'.
 *
 * If there is a selection, we defer to the browser.  In this case we clear out
 * the selection so the user knows we heard them, and also to give them a
 * chance to send a Meta-C by just hitting the key again.
 */
hterm.Keyboard.KeyMap.prototype.onMetaC_ = function(e, keyDef) {
  var document = this.keyboard.terminal.getDocument();
  if (e.shiftKey || document.getSelection().isCollapsed) {
    // If the shift key is being held, or there is no document selection, send
    // a Meta-C.  The keyboard code will add the ESC if metaSendsEscape is true,
    // we just have to decide between 'c' and 'C'.
    return keyDef.keyCap.substr(e.shiftKey ? 1 : 0, 1);
  }

  // Otherwise let the browser handle it as a copy command.
  if (this.keyboard.terminal.clearSelectionAfterCopy) {
    setTimeout(function() { document.getSelection().collapseToEnd(); }, 50);
  }
  return hterm.Keyboard.KeyActions.PASS;
};

/**
 * Either PASS or DEFAULT Meta-V, depending on preference.
 *
 * Always PASS Meta-Shift-V to allow browser to interpret the keystroke as
 * a paste command.
 */
hterm.Keyboard.KeyMap.prototype.onMetaV_ = function(e, keyDef) {
  if (e.shiftKey)
    return hterm.Keyboard.KeyActions.PASS;

  return this.keyboard.passMetaV ?
      hterm.Keyboard.KeyActions.PASS :
      hterm.Keyboard.KeyActions.DEFAULT;
};

/**
 * Handle font zooming.
 *
 * The browser's built-in zoom has a bit of an issue at certain zoom levels.
 * At some magnifications, the measured height of a row of text differs from
 * the height that was explicitly set.
 *
 * We override the browser zoom keys to change the ScrollPort's font size to
 * avoid the issue.
 */
hterm.Keyboard.KeyMap.prototype.onPlusMinusZero_ = function(e, keyDef) {
  if (!(this.keyboard.ctrlPlusMinusZeroZoom ^ e.shiftKey)) {
    // If ctrl-PMZ controls zoom and the shift key is pressed, or
    // ctrl-shift-PMZ controls zoom and this shift key is not pressed,
    // then we want to send the control code instead of affecting zoom.
    if (keyDef.keyCap == '-_')
      return '\x1f';  // ^_

    // Only ^_ is valid, the other sequences have no meaning.
    return hterm.Keyboard.KeyActions.CANCEL;
  }

  if (this.keyboard.terminal.getZoomFactor() != 1) {
    // If we're not at 1:1 zoom factor, let the Ctrl +/-/0 keys control the
    // browser zoom, so it's easier to for the user to get back to 100%.
    return hterm.Keyboard.KeyActions.PASS;
  }

  var cap = keyDef.keyCap.substr(0, 1);
  if (cap == '0') {
      this.keyboard.terminal.setFontSize(0);
  } else {
    var size = this.keyboard.terminal.getFontSize();

    if (cap == '-' || keyDef.keyCap == '[KP-]') {
      size -= 1;
    } else {
      size += 1;
    }

    this.keyboard.terminal.setFontSize(size);
  }

  return hterm.Keyboard.KeyActions.CANCEL;
};
// SOURCE FILE: hterm/js/hterm_keyboard_keypattern.js
// Copyright (c) 2015 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

/**
 * A record of modifier bits and keycode used to define a key binding.
 *
 * The modifier names are enumerated in the static KeyPattern.modifiers
 * property below.  Each modifier can be true, false, or "*".  True means
 * the modifier key must be present, false means it must not, and "*" means
 * it doesn't matter.
 */
hterm.Keyboard.KeyPattern = function(spec) {
  this.wildcardCount = 0;
  this.keyCode = spec.keyCode;

  hterm.Keyboard.KeyPattern.modifiers.forEach(function(mod) {
    this[mod] = spec[mod] || false;
    if (this[mod] == '*')
      this.wildcardCount++;
  }.bind(this));
};

/**
 * Valid modifier names.
 */
hterm.Keyboard.KeyPattern.modifiers = [
  'shift', 'ctrl', 'alt', 'meta'
];

/**
 * A compare callback for Array.prototype.sort().
 *
 * The bindings code wants to be sure to search through the strictest key
 * patterns first, so that loosely defined patterns have a lower priority than
 * exact patterns.
 *
 * @param {hterm.Keyboard.KeyPattern} a
 * @param {hterm.Keyboard.KeyPattern} b
 */
hterm.Keyboard.KeyPattern.sortCompare = function(a, b) {
  if (a.wildcardCount < b.wildcardCount)
    return -1;

  if (a.wildcardCount > b.wildcardCount)
    return 1;

  return 0;
};

/**
 * Private method used to match this key pattern against other key patterns
 * or key down events.
 *
 * @param {Object} The object to match.
 * @param {boolean} True if we should ignore wildcards.  Useful when you want
 *   to perform and exact match against another key pattern.
 */
hterm.Keyboard.KeyPattern.prototype.match_ = function(obj, exactMatch) {
  if (this.keyCode != obj.keyCode)
    return false;

  var rv = true;

  hterm.Keyboard.KeyPattern.modifiers.forEach(function(mod) {
    var modValue = (mod in obj) ? obj[mod] : false;
    if (!rv || (!exactMatch && this[mod] == '*') || this[mod] == modValue)
      return;

    rv = false;
  }.bind(this));

  return rv;
};

/**
 * Return true if the given keyDown object is a match for this key pattern.
 *
 * @param {Object} keyDown An object with a keyCode property and zero or
 *   more boolean properties representing key modifiers.  These property names
 *   must match those defined in hterm.Keyboard.KeyPattern.modifiers.
 */
hterm.Keyboard.KeyPattern.prototype.matchKeyDown = function(keyDown) {
  return this.match_(keyDown, false);
};

/**
 * Return true if the given hterm.Keyboard.KeyPattern is exactly the same as
 * this one.
 *
 * @param {hterm.Keyboard.KeyPattern}
 */
hterm.Keyboard.KeyPattern.prototype.matchKeyPattern = function(keyPattern) {
  return this.match_(keyPattern, true);
};
// SOURCE FILE: hterm/js/hterm_options.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

/**
 * @fileoverview This file implements the hterm.Options class,
 * which stores current operating conditions for the terminal.  This object is
 * used instead of a series of parameters to allow saving/restoring of cursor
 * conditions easily, and to provide an easy place for common configuration
 * options.
 *
 * Original code by Cory Maccarrone.
 */

/**
 * Constructor for the hterm.Options class, optionally acting as a copy
 * constructor.
 *
 * The defaults are as defined in http://www.vt100.net/docs/vt510-rm/DECSTR
 * except that we enable autowrap (wraparound) by default since that seems to
 * be what xterm does.
 *
 * @param {hterm.Options=} opt_copy Optional instance to copy.
 * @constructor
 */
hterm.Options = function(opt_copy) {
  // All attributes in this class are public to allow easy access by the
  // terminal.

  this.wraparound = opt_copy ? opt_copy.wraparound : true;
  this.reverseWraparound = opt_copy ? opt_copy.reverseWraparound : false;
  this.originMode = opt_copy ? opt_copy.originMode : false;
  this.autoCarriageReturn = opt_copy ? opt_copy.autoCarriageReturn : false;
  this.cursorVisible = opt_copy ? opt_copy.cursorVisible : false;
  this.cursorBlink = opt_copy ? opt_copy.cursorBlink : false;
  this.insertMode = opt_copy ? opt_copy.insertMode : false;
  this.reverseVideo = opt_copy ? opt_copy.reverseVideo : false;
  this.bracketedPaste = opt_copy ? opt_copy.bracketedPaste : false;
};
// SOURCE FILE: hterm/js/hterm_parser.js
// Copyright (c) 2015 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

lib.rtdep('hterm.Keyboard.KeyActions');

/**
 * @constructor
 * Parses the key definition syntax used for user keyboard customizations.
 */
hterm.Parser = function() {
  /**
   * @type {string} The source string.
   */
  this.source = '';

  /**
   * @type {number} The current position.
   */
  this.pos = 0;

  /**
   * @type {string?} The character at the current position.
   */
  this.ch = null;
};

hterm.Parser.prototype.error = function(message) {
  return new Error('Parse error at ' + this.pos + ': ' + message);
};

hterm.Parser.prototype.isComplete = function() {
  return this.pos == this.source.length;
};

hterm.Parser.prototype.reset = function(source, opt_pos) {
  this.source = source;
  this.pos = opt_pos || 0;
  this.ch = source.substr(0, 1);
};

/**
 * Parse a key sequence.
 *
 * A key sequence is zero or more of the key modifiers defined in
 * hterm.Parser.identifiers.modifierKeys followed by a key code.  Key
 * codes can be an integer or an identifier from
 * hterm.Parser.identifiers.keyCodes.  Modifiers and keyCodes should be joined
 * by the dash character.
 *
 * An asterisk "*" can be used to indicate that the unspecified modifiers
 * are optional.
 *
 * For example:
 *   A: Matches only an unmodified "A" character.
 *   65: Same as above.
 *   0x41: Same as above.
 *   Ctrl-A: Matches only Ctrl-A.
 *   Ctrl-65: Same as above.
 *   Ctrl-0x41: Same as above.
 *   Ctrl-Shift-A: Matches only Ctrl-Shift-A.
 *   Ctrl-*-A: Matches Ctrl-A, as well as any other key sequence that includes
 *     at least the Ctrl and A keys.
 *
 * @return {Object} An object with shift, ctrl, alt, meta, keyCode
 *   properties.
 */
hterm.Parser.prototype.parseKeySequence = function() {
  var rv = {
    keyCode: null
  };

  for (var k in hterm.Parser.identifiers.modifierKeys) {
    rv[hterm.Parser.identifiers.modifierKeys[k]] = false;
  }

  while (this.pos < this.source.length) {
    this.skipSpace();

    var token = this.parseToken();
    if (token.type == 'integer') {
      rv.keyCode = token.value;

    } else if (token.type == 'identifier') {
      var ucValue = token.value.toUpperCase();
      if (ucValue in hterm.Parser.identifiers.modifierKeys &&
          hterm.Parser.identifiers.modifierKeys.hasOwnProperty(ucValue)) {
        var mod = hterm.Parser.identifiers.modifierKeys[ucValue];
        if (rv[mod] && rv[mod] != '*')
          throw this.error('Duplicate modifier: ' + token.value);
        rv[mod] = true;

      } else if (ucValue in hterm.Parser.identifiers.keyCodes &&
                 hterm.Parser.identifiers.keyCodes.hasOwnProperty(ucValue)) {
        rv.keyCode = hterm.Parser.identifiers.keyCodes[ucValue];

      } else {
        throw this.error('Unknown key: ' + token.value);
      }

    } else if (token.type == 'symbol') {
      if (token.value == '*') {
        for (var id in hterm.Parser.identifiers.modifierKeys) {
          var p = hterm.Parser.identifiers.modifierKeys[id];
          if (!rv[p])
            rv[p] =  '*';
        }
      } else {
        throw this.error('Unexpected symbol: ' + token.value);
      }
    } else {
      throw this.error('Expected integer or identifier');
    }

    this.skipSpace();

    if (this.ch != '-')
      break;

    if (rv.keyCode != null)
      throw this.error('Extra definition after target key');

    this.advance(1);
  }

  if (rv.keyCode == null)
    throw this.error('Missing target key');

  return rv;
};

hterm.Parser.prototype.parseKeyAction = function() {
  this.skipSpace();

  var token = this.parseToken();

  if (token.type == 'string')
    return token.value;

  if (token.type == 'identifier') {
    if (token.value in hterm.Parser.identifiers.actions &&
        hterm.Parser.identifiers.actions.hasOwnProperty(token.value))
      return hterm.Parser.identifiers.actions[token.value];

    throw this.error('Unknown key action: ' + token.value);
  }

  throw this.error('Expected string or identifier');

};

hterm.Parser.prototype.peekString = function() {
  return this.ch == '\'' || this.ch == '"';
};

hterm.Parser.prototype.peekIdentifier = function() {
  return this.ch.match(/[a-z_]/i);
};

hterm.Parser.prototype.peekInteger = function() {
  return this.ch.match(/[0-9]/);
};

hterm.Parser.prototype.parseToken = function() {
  if (this.ch == '*') {
    var rv = {type: 'symbol', value: this.ch};
    this.advance(1);
    return rv;
  }

  if (this.peekIdentifier())
    return {type: 'identifier', value: this.parseIdentifier()};

  if (this.peekString())
    return {type: 'string', value: this.parseString()};

  if (this.peekInteger())
    return {type: 'integer', value: this.parseInteger()};


  throw this.error('Unexpected token');
};

hterm.Parser.prototype.parseIdentifier = function() {
  if (!this.peekIdentifier())
    throw this.error('Expected identifier');

  return this.parsePattern(/[a-z0-9_]+/ig);
};

hterm.Parser.prototype.parseInteger = function() {
  var base = 10;

  if (this.ch == '0' && this.pos < this.source.length - 1 &&
      this.source.substr(this.pos + 1, 1) == 'x') {
    return parseInt(this.parsePattern(/0x[0-9a-f]+/gi));
  }

  return parseInt(this.parsePattern(/\d+/g));
};

/**
 * Parse a single or double quoted string.
 *
 * The current position should point at the initial quote character.  Single
 * quoted strings will be treated literally, double quoted will process escapes.
 *
 * TODO(rginda): Variable interpolation.
 *
 * @param {ParseState} parseState
 * @param {string} quote A single or double-quote character.
 * @return {string}
 */
hterm.Parser.prototype.parseString = function() {
  var result = '';

  var quote = this.ch;
  if (quote != '"' && quote != '\'')
    throw this.error('String expected');

  this.advance(1);

  var re = new RegExp('[\\\\' + quote + ']', 'g');

  while (this.pos < this.source.length) {
    re.lastIndex = this.pos;
    if (!re.exec(this.source))
      throw this.error('Unterminated string literal');

    result += this.source.substring(this.pos, re.lastIndex - 1);

    this.advance(re.lastIndex - this.pos - 1);

    if (quote == '"' && this.ch == '\\') {
      this.advance(1);
      result += this.parseEscape();
      continue;
    }

    if (quote == '\'' && this.ch == '\\') {
      result += this.ch;
      this.advance(1);
      continue;
    }

    if (this.ch == quote) {
      this.advance(1);
      return result;
    }
  }

  throw this.error('Unterminated string literal');
};


/**
 * Parse an escape code from the current position (which should point to
 * the first character AFTER the leading backslash.)
 *
 * @return {string}
 */
hterm.Parser.prototype.parseEscape = function() {
  var map = {
    '"': '"',
    '\'': '\'',
    '\\': '\\',
    'a': '\x07',
    'b': '\x08',
    'e': '\x1b',
    'f': '\x0c',
    'n': '\x0a',
    'r': '\x0d',
    't': '\x09',
    'v': '\x0b',
    'x': function() {
      var value = this.parsePattern(/[a-z0-9]{2}/ig);
      return String.fromCharCode(parseInt(value, 16));
    },
    'u': function() {
      var value = this.parsePattern(/[a-z0-9]{4}/ig);
      return String.fromCharCode(parseInt(value, 16));
    }
  };

  if (!(this.ch in map && map.hasOwnProperty(this.ch)))
    throw this.error('Unknown escape: ' + this.ch);

  var value = map[this.ch];
  this.advance(1);

  if (typeof value == 'function')
    value = value.call(this);

  return value;
};

/**
 * Parse the given pattern starting from the current position.
 *
 * @param {RegExp} pattern A pattern representing the characters to span.  MUST
 *   include the "global" RegExp flag.
 * @return {string}
 */
hterm.Parser.prototype.parsePattern = function(pattern) {
  if (!pattern.global)
    throw this.error('Internal error: Span patterns must be global');

  pattern.lastIndex = this.pos;
  var ary = pattern.exec(this.source);

  if (!ary || pattern.lastIndex - ary[0].length != this.pos)
    throw this.error('Expected match for: ' + pattern);

  this.pos = pattern.lastIndex - 1;
  this.advance(1);

  return ary[0];
};


/**
 * Advance the current position.
 *
 * @param {number} count
 */
hterm.Parser.prototype.advance = function(count) {
  this.pos += count;
  this.ch = this.source.substr(this.pos, 1);
};

/**
 * @param {string=} opt_expect A list of valid non-whitespace characters to
 *   terminate on.
 * @return {void}
 */
hterm.Parser.prototype.skipSpace = function(opt_expect) {
  if (!/\s/.test(this.ch))
    return;

  var re = /\s+/gm;
  re.lastIndex = this.pos;

  var source = this.source;
  if (re.exec(source))
    this.pos = re.lastIndex;

  this.ch = this.source.substr(this.pos, 1);

  if (opt_expect) {
    if (this.ch.indexOf(opt_expect) == -1) {
      throw this.error('Expected one of ' + opt_expect + ', found: ' +
          this.ch);
    }
  }
};
// SOURCE FILE: hterm/js/hterm_parser_identifiers.js
// Copyright (c) 2015 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

/**
 * Collections of identifier for hterm.Parser.
 */
hterm.Parser.identifiers = {};

/**
 * Modifier key names used when defining key sequences.
 *
 * These are upper case so we can normalize the user input and be forgiving.
 * "CTRL-A" and "Ctrl-A" and "ctrl-a" are all accepted.
 *
 * Note: Names here cannot overlap with hterm.Parser.identifiers.keyCodes.
 */
hterm.Parser.identifiers.modifierKeys = {
  SHIFT: 'shift',
  CTRL: 'ctrl',
  // Common alias.
  CONTROL: 'ctrl',
  ALT: 'alt',
  META: 'meta'
};

/**
 * Key codes useful when defining key sequences.
 *
 * Punctuation is mostly left out of this list because they can move around
 * based on keyboard locale and browser.
 *
 * In a key sequence like "Ctrl-ESC", the ESC comes from this list of
 * identifiers.  It is equivalent to "Ctrl-27" and "Ctrl-0x1b".
 *
 * These are upper case so we can normalize the user input and be forgiving.
 * "Ctrl-ESC" and "Ctrl-Esc" an "Ctrl-esc" are all accepted.
 *
 * We also include common aliases for the same key.  "Esc" and "Escape" are the
 * same key.
 *
 * Note: Names here cannot overlap with hterm.Parser.identifiers.modifierKeys.
 */
hterm.Parser.identifiers.keyCodes = {
  // Top row.
  ESCAPE: 27,
  ESC: 27,
  F1: 112,
  F2: 113,
  F3: 114,
  F4: 115,
  F5: 116,
  F6: 117,
  F7: 118,
  F8: 119,
  F9: 120,
  F10: 121,
  F11: 122,
  F12: 123,

  // Row two.
  ONE: 49,
  TWO: 50,
  THREE: 51,
  FOUR: 52,
  FIVE: 53,
  SIX: 54,
  SEVEN: 55,
  EIGHT: 56,
  NINE: 57,
  ZERO: 48,
  BACKSPACE: 8,
  BKSP: 8,
  BS: 8,

  // Row three.
  TAB: 9,
  Q: 81,
  W: 87,
  E: 69,
  R: 82,
  T: 84,
  Y: 89,
  U: 85,
  I: 73,
  O: 79,
  P: 80,

  // Row four.
  CAPS_LOCK: 20,
  CAPSLOCK: 20,
  CAPS: 20,
  A: 65,
  S: 83,
  D: 68,
  F: 70,
  G: 71,
  H: 72,
  J: 74,
  K: 75,
  L: 76,
  // We map enter and return together even though enter should really be 10
  // because most people don't know or care about the history here.  Plus,
  // most keyboards/programs map them together already.  If they really want
  // to bind them differently, they can also use the numeric value.
  ENTER: 13,
  ENT: 13,
  RETURN: 13,
  RET: 13,

  // Row five.
  Z: 90,
  X: 88,
  C: 67,
  V: 86,
  B: 66,
  N: 78,
  M: 77,

  // Etc.
  SPACE: 32,
  SP: 32,
  PRINT_SCREEN: 42,
  PRTSC: 42,
  SCROLL_LOCK: 145,
  SCRLK: 145,
  BREAK: 19,
  BRK: 19,
  INSERT: 45,
  INS: 45,
  HOME: 36,
  PAGE_UP: 33,
  PGUP: 33,
  DELETE: 46,
  DEL: 46,
  END: 35,
  PAGE_DOWN: 34,
  PGDOWN: 34,
  PGDN: 34,
  UP: 38,
  DOWN: 40,
  RIGHT: 39,
  LEFT: 37,
  NUMLOCK: 144,

  // Keypad
  KP0: 96,
  KP1: 97,
  KP2: 98,
  KP3: 99,
  KP4: 100,
  KP5: 101,
  KP6: 102,
  KP7: 103,
  KP8: 104,
  KP9: 105,
  KP_PLUS: 107,
  KP_ADD: 107,
  KP_MINUS: 109,
  KP_SUBTRACT: 109,
  KP_STAR: 106,
  KP_MULTIPLY: 106,
  KP_DIVIDE: 111,
  KP_DECIMAL: 110,
  KP_PERIOD: 110,

  // Chrome OS media keys
  NAVIGATE_BACK: 166,
  NAVIGATE_FORWARD: 167,
  RELOAD: 168,
  FULL_SCREEN: 183,
  WINDOW_OVERVIEW: 182,
  BRIGHTNESS_UP: 216,
  BRIGHTNESS_DOWN: 217
};

/**
 * Identifiers for use in key actions.
 */
hterm.Parser.identifiers.actions = {
  /**
   * Prevent the browser and operating system from handling the event.
   */
  CANCEL: hterm.Keyboard.KeyActions.CANCEL,

  /**
   * Wait for a "keypress" event, send the keypress charCode to the host.
   */
  DEFAULT: hterm.Keyboard.KeyActions.DEFAULT,

  /**
   * Let the browser or operating system handle the key.
   */
  PASS: hterm.Keyboard.KeyActions.PASS,

  /**
   * Scroll the terminal one line up.
   */
  scrollLineUp: function(terminal) {
    terminal.scrollLineUp();
    return hterm.Keyboard.KeyActions.CANCEL;
  },

  /**
   * Scroll the terminal one line down.
   */
  scrollLineDown: function(terminal) {
    terminal.scrollLineDown();
    return hterm.Keyboard.KeyActions.CANCEL;
  },

  /**
   * Scroll the terminal one page up.
   */
  scrollPageUp: function(terminal) {
    terminal.scrollPageUp();
    return hterm.Keyboard.KeyActions.CANCEL;
  },

  /**
   * Scroll the terminal one page down.
   */
  scrollPageDown: function(terminal) {
    terminal.scrollPageDown();
    return hterm.Keyboard.KeyActions.CANCEL;
  },

  /**
   * Scroll the terminal to the top.
   */
  scrollToTop: function(terminal) {
    terminal.scrollHome();
    return hterm.Keyboard.KeyActions.CANCEL;
  },

  /**
   * Scroll the terminal to the bottom.
   */
  scrollToBottom: function(terminal) {
    terminal.scrollEnd();
    return hterm.Keyboard.KeyActions.CANCEL;
  },

  /**
   * Clear the active screen and move the cursor to (0,0).
   */
  clearScreen: function(terminal) {
    terminal.clearHome();
    return hterm.Keyboard.KeyActions.CANCEL;
  },

  /**
   * Clear the scrollback buffer.
   */
  clearScrollback: function(terminal) {
    terminal.clearScrollback();
    return hterm.Keyboard.KeyActions.CANCEL;
  },

  /**
   * Clear the terminal and scrollback buffer and move the cursor to (0,0).
   */
  clearTerminal: function(terminal) {
    terminal.wipeContents();
    return hterm.Keyboard.KeyActions.CANCEL;
  },

  /**
   * Perform a full terminal reset.
   */
  fullReset: function(terminal) {
    terminal.reset();
    return hterm.Keyboard.KeyActions.CANCEL;
  },

  /**
   * Perform a soft terminal reset.
   */
  softReset: function(terminal) {
    terminal.softReset();
    return hterm.Keyboard.KeyActions.CANCEL;
  },
};
// SOURCE FILE: hterm/js/hterm_preference_manager.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

lib.rtdep('lib.f', 'lib.Storage');

/**
 * PreferenceManager subclass managing global NaSSH preferences.
 *
 * This is currently just an ordered list of known connection profiles.
 */
hterm.PreferenceManager = function(profileId) {
  lib.PreferenceManager.call(this, hterm.defaultStorage,
                             hterm.PreferenceManager.prefix_ + profileId);
  Object.entries(hterm.PreferenceManager.defaultPreferences).forEach(
      ([key, entry]) => {
        this.definePreference(key, entry['default']);
      });
};

/**
 * The storage key prefix to namespace the preferences.
 */
hterm.PreferenceManager.prefix_ = '/hterm/profiles/';

/**
 * List all the defined profiles.
 *
 * @param {function(Array<string>)} callback Called with the list of profiles.
 */
hterm.PreferenceManager.listProfiles = function(callback) {
  hterm.defaultStorage.getItems(null, (items) => {
    const profiles = {};
    for (let key of Object.keys(items)) {
      if (key.startsWith(hterm.PreferenceManager.prefix_)) {
        // Turn "/hterm/profiles/foo/bar/cow" to "foo/bar/cow".
        const subKey = key.slice(hterm.PreferenceManager.prefix_.length);
        // Turn "foo/bar/cow" into "foo".
        profiles[subKey.split('/', 1)[0]] = true;
      }
    }
    callback(Object.keys(profiles));
  });
};

hterm.PreferenceManager.categories = {};
hterm.PreferenceManager.categories.Keyboard = 'Keyboard';
hterm.PreferenceManager.categories.Appearance = 'Appearance';
hterm.PreferenceManager.categories.CopyPaste = 'CopyPaste';
hterm.PreferenceManager.categories.Sounds = 'Sounds';
hterm.PreferenceManager.categories.Scrolling = 'Scrolling';
hterm.PreferenceManager.categories.Encoding = 'Encoding';
hterm.PreferenceManager.categories.Extensions = 'Extensions';
hterm.PreferenceManager.categories.Miscellaneous = 'Miscellaneous';

/**
 * List of categories, ordered by display order (top to bottom)
 */
hterm.PreferenceManager.categoryDefinitions = [
  { id: hterm.PreferenceManager.categories.Appearance,
    text: 'Appearance (fonts, colors, images)'},
  { id: hterm.PreferenceManager.categories.CopyPaste,
    text: 'Copy & Paste'},
  { id: hterm.PreferenceManager.categories.Encoding,
    text: 'Encoding'},
  { id: hterm.PreferenceManager.categories.Keyboard,
    text: 'Keyboard'},
  { id: hterm.PreferenceManager.categories.Scrolling,
    text: 'Scrolling'},
  { id: hterm.PreferenceManager.categories.Sounds,
    text: 'Sounds'},
  { id: hterm.PreferenceManager.categories.Extensions,
    text: 'Extensions'},
  { id: hterm.PreferenceManager.categories.Miscellaneous,
    text: 'Miscellaneous'}
];

/**
 * Internal helper to create a default preference object.
 *
 * @param {hterm.PreferenceManager.categories} category The pref category.
 * @param {string} name The user readable name/title.
 * @param {Object} defaultValue The default pref value.
 * @param {Object} type The type for this pref (or an array for enums).
 * @param {string} help The user readable help text.
 * @return {Object} The default pref object.
 */
hterm.PreferenceManager.definePref_ = function(
    name, category, defaultValue, type, help) {
  return {
    'name': name,
    'category': category,
    'default': defaultValue,
    'type': type,
    'help': help,
  };
};

hterm.PreferenceManager.defaultPreferences = {
  'alt-gr-mode': hterm.PreferenceManager.definePref_(
      'AltGr key mode',
      hterm.PreferenceManager.categories.Keyboard,
      null, [null, 'none', 'ctrl-alt', 'left-alt', 'right-alt'],
      `Select an AltGr detection heuristic.\n` +
      `\n` +
      `'null': Autodetect based on navigator.language:\n` +
      `      'en-us' => 'none', else => 'right-alt'\n` +
      `'none': Disable any AltGr related munging.\n` +
      `'ctrl-alt': Assume Ctrl+Alt means AltGr.\n` +
      `'left-alt': Assume left Alt means AltGr.\n` +
      `'right-alt': Assume right Alt means AltGr.`
  ),

  'alt-backspace-is-meta-backspace': hterm.PreferenceManager.definePref_(
      'Alt-Backspace is Meta-Backspace',
      hterm.PreferenceManager.categories.Keyboard,
      false, 'bool',
      `If set, undoes the Chrome OS Alt-Backspace->DEL remap, so that ` +
      `Alt-Backspace indeed is Alt-Backspace.`
  ),

  'alt-is-meta': hterm.PreferenceManager.definePref_(
      'Treat Alt key as Meta key',
      hterm.PreferenceManager.categories.Keyboard,
      false, 'bool',
      `Whether the Alt key acts as a Meta key or as a distinct Alt key.`
  ),

  'alt-sends-what': hterm.PreferenceManager.definePref_(
      'Alt key modifier handling',
      hterm.PreferenceManager.categories.Keyboard,
      'escape', ['escape', '8-bit', 'browser-key'],
      `Controls how the Alt key is handled.\n` +
      `\n` +
      `  escape: Send an ESC prefix.\n` +
      `  8-bit: Add 128 to the typed character as in xterm.\n` +
      `  browser-key: Wait for the keypress event and see what the browser\n` +
      `    says. (This won't work well on platforms where the browser\n` +
      `    performs a default action for some Alt sequences.)`
  ),

  'audible-bell-sound': hterm.PreferenceManager.definePref_(
      'Alert bell sound (URI)',
      hterm.PreferenceManager.categories.Sounds,
      'lib-resource:hterm/audio/bell', 'url',
      `URL of the terminal bell sound. Empty string for no audible bell.`
  ),

  'desktop-notification-bell': hterm.PreferenceManager.definePref_(
      'Create desktop notifications for alert bells',
      hterm.PreferenceManager.categories.Sounds,
      false, 'bool',
      `If true, terminal bells in the background will create a Web ` +
      `Notification. https://www.w3.org/TR/notifications/\n` +
      `\n` +
      `Displaying notifications requires permission from the user. When this ` +
      `option is set to true, hterm will attempt to ask the user for ` +
      `permission if necessary. Browsers may not show this permission ` +
      `request if it was not triggered by a user action.\n` +
      `\n` +
      `Chrome extensions with the "notifications" permission have permission ` +
      `to display notifications.`
  ),

  'background-color': hterm.PreferenceManager.definePref_(
      'Background color',
      hterm.PreferenceManager.categories.Appearance,
      'rgb(16, 16, 16)', 'color',
      `The background color for text with no other color attributes.`
  ),

  'background-image': hterm.PreferenceManager.definePref_(
      'Background image',
      hterm.PreferenceManager.categories.Appearance,
      '', 'string',
      `CSS value of the background image. Empty string for no image.\n` +
      `\n` +
      `For example:\n` +
      `  url(https://goo.gl/anedTK)\n` +
      `  linear-gradient(top bottom, blue, red)`
  ),

  'background-size': hterm.PreferenceManager.definePref_(
      'Background image size',
      hterm.PreferenceManager.categories.Appearance,
      '', 'string',
      `CSS value of the background image size.`
  ),

  'background-position': hterm.PreferenceManager.definePref_(
      'Background image position',
      hterm.PreferenceManager.categories.Appearance,
      '', 'string',
      `CSS value of the background image position.\n` +
      `\n` +
      `For example:\n` +
      `  10% 10%\n` +
      `  center`
  ),

  'backspace-sends-backspace': hterm.PreferenceManager.definePref_(
      'Backspace key behavior',
      hterm.PreferenceManager.categories.Keyboard,
      false, 'bool',
      `If true, the backspace should send BS ('\\x08', aka ^H). Otherwise ` +
      `the backspace key should send '\\x7f'.`
  ),

  'character-map-overrides': hterm.PreferenceManager.definePref_(
      'Character map overrides',
      hterm.PreferenceManager.categories.Appearance,
      null, 'value',
      `This is specified as an object. It is a sparse array, where each ` +
      `property is the character set code and the value is an object that is ` +
      `a sparse array itself. In that sparse array, each property is the ` +
      `received character and the value is the displayed character.\n` +
      `\n` +
      `For example:\n` +
      `  {"0":{"+":"\\u2192",",":"\\u2190","-":"\\u2191",".":"\\u2193", ` +
      `"0":"\\u2588"}}`
  ),

  'close-on-exit': hterm.PreferenceManager.definePref_(
      'Close window on exit',
      hterm.PreferenceManager.categories.Miscellaneous,
      true, 'bool',
      `Whether to close the window when the command finishes executing.`
  ),

  'cursor-blink': hterm.PreferenceManager.definePref_(
      'Cursor blink',
      hterm.PreferenceManager.categories.Appearance,
      false, 'bool',
      `Whether the text cursor blinks by default. This can be toggled at ` +
      `runtime via terminal escape sequences.`
  ),

  'cursor-blink-cycle': hterm.PreferenceManager.definePref_(
      'Cursor blink rate',
      hterm.PreferenceManager.categories.Appearance,
      [1000, 500], 'value',
      `The text cursor blink rate in milliseconds.\n` +
      `\n` +
      `A two element array, the first of which is how long the text cursor ` +
      `should be on, second is how long it should be off.`
  ),

  'cursor-color': hterm.PreferenceManager.definePref_(
      'Text cursor color',
      hterm.PreferenceManager.categories.Appearance,
      'rgba(255, 0, 0, 0.5)', 'color',
      `The color of the visible text cursor.`
  ),

  'color-palette-overrides': hterm.PreferenceManager.definePref_(
      'Initial color palette',
      hterm.PreferenceManager.categories.Appearance,
      null, 'value',
      `Override colors in the default palette.\n` +
      `\n` +
      `This can be specified as an array or an object. If specified as an ` +
      `object it is assumed to be a sparse array, where each property ` +
      `is a numeric index into the color palette.\n` +
      `\n` +
      `Values can be specified as almost any CSS color value. This ` +
      `includes #RGB, #RRGGBB, rgb(...), rgba(...), and any color names ` +
      `that are also part of the standard X11 rgb.txt file.\n` +
      `\n` +
      `You can use 'null' to specify that the default value should be not ` +
      `be changed. This is useful for skipping a small number of indices ` +
      `when the value is specified as an array.\n` +
      `\n` +
      `For example, these both set color index 1 to blue:\n` +
      `  {1: "#0000ff"}\n` +
      `  [null, "#0000ff"]`
  ),

  'copy-on-select': hterm.PreferenceManager.definePref_(
      'Automatically copy selected content',
      hterm.PreferenceManager.categories.CopyPaste,
      true, 'bool',
      `Automatically copy mouse selection to the clipboard.`
  ),

  'use-default-window-copy': hterm.PreferenceManager.definePref_(
      'Let the browser handle text copying',
      hterm.PreferenceManager.categories.CopyPaste,
      false, 'bool',
      `Whether to use the default browser/OS's copy behavior.\n` +
      `\n` +
      `Allow the browser/OS to handle the copy event directly which might ` +
      `improve compatibility with some systems (where copying doesn't work ` +
      `at all), but makes the text selection less robust.\n` +
      `\n` +
      `For example, long lines that were automatically line wrapped will ` +
      `be copied with the newlines still in them.`
  ),

  'clear-selection-after-copy': hterm.PreferenceManager.definePref_(
      'Automatically clear text selection',
      hterm.PreferenceManager.categories.CopyPaste,
      true, 'bool',
      `Whether to clear the selection after copying.`
  ),

  'ctrl-plus-minus-zero-zoom': hterm.PreferenceManager.definePref_(
      'Ctrl-+/-/0 zoom behavior',
      hterm.PreferenceManager.categories.Keyboard,
      true, 'bool',
      `If true, Ctrl-Plus/Minus/Zero controls zoom.\n` +
      `If false, Ctrl-Shift-Plus/Minus/Zero controls zoom, Ctrl-Minus sends ` +
      `^_, Ctrl-Plus/Zero do nothing.`
  ),

  'ctrl-c-copy': hterm.PreferenceManager.definePref_(
      'Ctrl-C copy behavior',
      hterm.PreferenceManager.categories.Keyboard,
      false, 'bool',
      `Ctrl-C copies if true, send ^C to host if false.\n` +
      `Ctrl-Shift-C sends ^C to host if true, copies if false.`
  ),

  'ctrl-v-paste': hterm.PreferenceManager.definePref_(
      'Ctrl-V paste behavior',
      hterm.PreferenceManager.categories.Keyboard,
      false, 'bool',
      `Ctrl-V pastes if true, send ^V to host if false.\n` +
      `Ctrl-Shift-V sends ^V to host if true, pastes if false.`
  ),

  'east-asian-ambiguous-as-two-column': hterm.PreferenceManager.definePref_(
      'East Asian Ambiguous use two columns',
      hterm.PreferenceManager.categories.Keyboard,
      false, 'bool',
      `Whether East Asian Ambiguous characters have two column width.`
  ),

  'enable-8-bit-control': hterm.PreferenceManager.definePref_(
      'Support non-UTF-8 C1 control characters',
      hterm.PreferenceManager.categories.Keyboard,
      false, 'bool',
      `True to enable 8-bit control characters, false to ignore them.\n` +
      `\n` +
      `We'll respect the two-byte versions of these control characters ` +
      `regardless of this setting.`
  ),

  'enable-bold': hterm.PreferenceManager.definePref_(
      'Bold text behavior',
      hterm.PreferenceManager.categories.Appearance,
      null, 'tristate',
      `If true, use bold weight font for text with the bold/bright ` +
      `attribute. False to use the normal weight font. Null to autodetect.`
  ),

  'enable-bold-as-bright': hterm.PreferenceManager.definePref_(
      'Use bright colors with bold text',
      hterm.PreferenceManager.categories.Appearance,
      true, 'bool',
      `If true, use bright colors (8-15 on a 16 color palette) for any text ` +
      `with the bold attribute. False otherwise.`
  ),

  'enable-blink': hterm.PreferenceManager.definePref_(
      'Enable blinking text',
      hterm.PreferenceManager.categories.Appearance,
      true, 'bool',
      `If true, respect the blink attribute. False to ignore it.`
  ),

  'enable-clipboard-notice': hterm.PreferenceManager.definePref_(
      'Show notification when copying content',
      hterm.PreferenceManager.categories.CopyPaste,
      true, 'bool',
      `Whether to show a message in the terminal when the host writes to the ` +
      `clipboard.`
  ),

  'enable-clipboard-write': hterm.PreferenceManager.definePref_(
      'Allow remote clipboard writes',
      hterm.PreferenceManager.categories.CopyPaste,
      true, 'bool',
      `Allow the remote host to write directly to the local system ` +
      `clipboard.\n` +
      `Read access is never granted regardless of this setting.\n` +
      `\n` +
      `This is used to control access to features like OSC-52.`
  ),

  'enable-dec12': hterm.PreferenceManager.definePref_(
      'Allow changing of text cursor blinking',
      hterm.PreferenceManager.categories.Miscellaneous,
      false, 'bool',
      `Respect the host's attempt to change the text cursor blink status ` +
      `using DEC Private Mode 12.`
  ),

  'enable-csi-j-3': hterm.PreferenceManager.definePref_(
      'Allow clearing of scrollback buffer (CSI-J-3)',
      hterm.PreferenceManager.categories.Miscellaneous,
      true, 'bool',
      `Whether CSI-J (Erase Display) mode 3 may clear the terminal ` +
      `scrollback buffer.\n` +
      `\n` +
      `Enabling this by default is safe.`
  ),

  'environment': hterm.PreferenceManager.definePref_(
      'Environment variables',
      hterm.PreferenceManager.categories.Miscellaneous,
      {
        // Signal ncurses based apps to use UTF-8 output instead of legacy
        // drawing modes (which only work in ISO-2022 mode).  Since hterm is
        // always UTF-8, this shouldn't cause problems.
        'NCURSES_NO_UTF8_ACS': '1',
        'TERM': 'xterm-256color',
        // Set this env var that a bunch of mainstream terminal emulators set
        // to indicate we support true colors.
        // https://gist.github.com/XVilka/8346728
        'COLORTERM': 'truecolor',
      },
      'value',
      `The initial set of environment variables, as an object.`
  ),

  'font-family': hterm.PreferenceManager.definePref_(
      'Text font family',
      hterm.PreferenceManager.categories.Appearance,
      '"DejaVu Sans Mono", "Noto Sans Mono", "Everson Mono", FreeMono, ' +
      'Menlo, Terminal, monospace',
      'string',
      `Default font family for the terminal text.`
  ),

  'font-size': hterm.PreferenceManager.definePref_(
      'Text font size',
      hterm.PreferenceManager.categories.Appearance,
      15, 'int',
      `The default font size in pixels.`
  ),

  'font-smoothing': hterm.PreferenceManager.definePref_(
      'Text font smoothing',
      hterm.PreferenceManager.categories.Appearance,
      'antialiased', 'string',
      `CSS font-smoothing property.`
  ),

  'foreground-color': hterm.PreferenceManager.definePref_(
      'Text color',
      hterm.PreferenceManager.categories.Appearance,
      'rgb(240, 240, 240)', 'color',
      `The foreground color for text with no other color attributes.`
  ),

  'hide-mouse-while-typing': hterm.PreferenceManager.definePref_(
      'Hide mouse cursor while typing',
      hterm.PreferenceManager.categories.Keyboard,
      null, 'tristate',
      `Whether to automatically hide the mouse cursor when typing. ` +
      `By default, autodetect whether the platform/OS handles this.\n` +
      `\n` +
      `Note: Some operating systems may override this setting and thus you ` +
      `might not be able to always disable it.`
  ),

  'home-keys-scroll': hterm.PreferenceManager.definePref_(
      'Home/End key scroll behavior',
      hterm.PreferenceManager.categories.Keyboard,
      false, 'bool',
      `If true, Home/End controls the terminal scrollbar and Shift-Home/` +
      `Shift-End are sent to the remote host. If false, then Home/End are ` +
      `sent to the remote host and Shift-Home/Shift-End scrolls.`
  ),

  'keybindings': hterm.PreferenceManager.definePref_(
      'Keyboard bindings/shortcuts',
      hterm.PreferenceManager.categories.Keyboard,
      null, 'value',
      `A map of key sequence to key actions. Key sequences include zero or ` +
      `more modifier keys followed by a key code. Key codes can be decimal ` +
      `or hexadecimal numbers, or a key identifier. Key actions can be ` +
      `specified as a string to send to the host, or an action identifier. ` +
      `For a full explanation of the format, see https://goo.gl/LWRndr.\n` +
      `\n` +
      `Sample keybindings:\n` +
      `{\n` +
      `  "Ctrl-Alt-K": "clearTerminal",\n` +
      `  "Ctrl-Shift-L": "PASS",\n` +
      `  "Ctrl-H": "'Hello World'"\n` +
      `}`
  ),

  'media-keys-are-fkeys': hterm.PreferenceManager.definePref_(
      'Media keys are Fkeys',
      hterm.PreferenceManager.categories.Keyboard,
      false, 'bool',
      `If true, convert media keys to their Fkey equivalent. If false, let ` +
      `the browser handle the keys.`
  ),

  'meta-sends-escape': hterm.PreferenceManager.definePref_(
      'Meta key modifier handling',
      hterm.PreferenceManager.categories.Keyboard,
      true, 'bool',
      `Send an ESC prefix when pressing a key while holding the Meta key.\n` +
      `\n` +
      `For example, when enabled, pressing Meta-K will send ^[k as if you ` +
      `typed Escape then k. When disabled, only k will be sent.`
  ),

  'mouse-right-click-paste': hterm.PreferenceManager.definePref_(
      'Mouse right clicks paste content',
      hterm.PreferenceManager.categories.CopyPaste,
      true, 'bool',
      `Paste on right mouse button clicks.\n` +
      `\n` +
      `This option is independent of the "mouse-paste-button" setting.\n` +
      `\n` +
      `Note: This will handle left & right handed mice correctly.`
  ),

  'mouse-paste-button': hterm.PreferenceManager.definePref_(
      'Mouse button paste',
      hterm.PreferenceManager.categories.CopyPaste,
      null, [null, 0, 1, 2, 3, 4, 5, 6],
      `Mouse paste button, or null to autodetect.\n` +
      `\n` +
      `For autodetect, we'll use the middle mouse button for non-X11 ` +
      `platforms (including Chrome OS). On X11, we'll use the right mouse ` +
      `button (since the native window manager should paste via the middle ` +
      `mouse button).\n` +
      `\n` +
      `0 == left (primary) button.\n` +
      `1 == middle (auxiliary) button.\n` +
      `2 == right (secondary) button.\n` +
      `\n` +
      `This option is independent of the setting for right-click paste.\n` +
      `\n` +
      `Note: This will handle left & right handed mice correctly.`
  ),

  'word-break-match-left': hterm.PreferenceManager.definePref_(
      'Automatic selection halting (to the left)',
      hterm.PreferenceManager.categories.CopyPaste,
      '[^\\s\\[\\](){}<>"\'\\^!@#$%&*,;:`]', 'string',
      `Regular expression to halt matching to the left (start) of a ` +
      `selection.\n` +
      `\n` +
      `Normally this is a character class to reject specific characters.\n` +
      `We allow "~" and "." by default as paths frequently start with those.`
  ),

  'word-break-match-right': hterm.PreferenceManager.definePref_(
      'Automatic selection halting (to the right)',
      hterm.PreferenceManager.categories.CopyPaste,
      '[^\\s\\[\\](){}<>"\'\\^!@#$%&*,;:~.`]', 'string',
      `Regular expression to halt matching to the right (end) of a ` +
      `selection.\n` +
      `\n` +
      `Normally this is a character class to reject specific characters.`
  ),

  'word-break-match-middle': hterm.PreferenceManager.definePref_(
      'Word break characters',
      hterm.PreferenceManager.categories.CopyPaste,
      '[^\\s\\[\\](){}<>"\'\\^]*', 'string',
      `Regular expression to match all the characters in the middle.\n` +
      `\n` +
      `Normally this is a character class to reject specific characters.\n` +
      `\n` +
      `Used to expand the selection surrounding the starting point.`
  ),

  'page-keys-scroll': hterm.PreferenceManager.definePref_(
      'Page Up/Down key scroll behavior',
      hterm.PreferenceManager.categories.Keyboard,
      false, 'bool',
      `If true, Page Up/Page Down controls the terminal scrollbar and ` +
      `Shift-Page Up/Shift-Page Down are sent to the remote host. If false, ` +
      `then Page Up/Page Down are sent to the remote host and Shift-Page Up/` +
      `Shift-Page Down scrolls.`
  ),

  'pass-alt-number': hterm.PreferenceManager.definePref_(
      'Pass Alt-1..9 key behavior',
      hterm.PreferenceManager.categories.Keyboard,
      null, 'tristate',
      `Whether Alt-1..9 is passed to the browser.\n` +
      `\n` +
      `This is handy when running hterm in a browser tab, so that you don't ` +
      `lose Chrome's "switch to tab" keyboard accelerators. When not running ` +
      `in a tab it's better to send these keys to the host so they can be ` +
      `used in vim or emacs.\n` +
      `\n` +
      `If true, Alt-1..9 will be handled by the browser. If false, Alt-1..9 ` +
      `will be sent to the host. If null, autodetect based on browser ` +
      `platform and window type.`
  ),

  'pass-ctrl-number': hterm.PreferenceManager.definePref_(
      'Pass Ctrl-1..9 key behavior',
      hterm.PreferenceManager.categories.Keyboard,
      null, 'tristate',
      `Whether Ctrl-1..9 is passed to the browser.\n` +
      `\n` +
      `This is handy when running hterm in a browser tab, so that you don't ` +
      `lose Chrome's "switch to tab" keyboard accelerators. When not running ` +
      `in a tab it's better to send these keys to the host so they can be ` +
      `used in vim or emacs.\n` +
      `\n` +
      `If true, Ctrl-1..9 will be handled by the browser. If false, ` +
      `Ctrl-1..9 will be sent to the host. If null, autodetect based on ` +
      `browser platform and window type.`
  ),

  'pass-meta-number': hterm.PreferenceManager.definePref_(
      'Pass Meta-1..9 key behavior',
      hterm.PreferenceManager.categories.Keyboard,
      null, 'tristate',
      `Whether Meta-1..9 is passed to the browser.\n` +
      `\n` +
      `This is handy when running hterm in a browser tab, so that you don't ` +
      `lose Chrome's "switch to tab" keyboard accelerators. When not running ` +
      `in a tab it's better to send these keys to the host so they can be ` +
      `used in vim or emacs.\n` +
      `\n` +
      `If true, Meta-1..9 will be handled by the browser. If false, ` +
      `Meta-1..9 will be sent to the host. If null, autodetect based on ` +
      `browser platform and window type.`
  ),

  'pass-meta-v': hterm.PreferenceManager.definePref_(
      'Pass Meta-V key behavior',
      hterm.PreferenceManager.categories.Keyboard,
      true, 'bool',
      `Whether Meta-V gets passed to host.`
  ),

  'paste-on-drop': hterm.PreferenceManager.definePref_(
      'Allow drag & drop to paste',
      hterm.PreferenceManager.categories.CopyPaste,
      true, 'bool',
      `If true, Drag and dropped text will paste into terminal.\n` +
      `If false, dropped text will be ignored.`
  ),

  'receive-encoding': hterm.PreferenceManager.definePref_(
      'Receive encoding',
      hterm.PreferenceManager.categories.Encoding,
      'utf-8', ['utf-8', 'raw'],
      `Set the expected encoding for data received from the host.\n` +
      `If the encodings do not match, visual bugs are likely to be ` +
      `observed.\n` +
      `\n` +
      `Valid values are 'utf-8' and 'raw'.`
  ),

  'scroll-on-keystroke': hterm.PreferenceManager.definePref_(
      'Scroll to bottom after keystroke',
      hterm.PreferenceManager.categories.Scrolling,
      true, 'bool',
      `Whether to scroll to the bottom on any keystroke.`
  ),

  'scroll-on-output': hterm.PreferenceManager.definePref_(
      'Scroll to bottom after new output',
      hterm.PreferenceManager.categories.Scrolling,
      false, 'bool',
      `Whether to scroll to the bottom on terminal output.`
  ),

  'scrollbar-visible': hterm.PreferenceManager.definePref_(
      'Scrollbar visibility',
      hterm.PreferenceManager.categories.Scrolling,
      true, 'bool',
      `The vertical scrollbar mode.`
  ),

  'scroll-wheel-may-send-arrow-keys': hterm.PreferenceManager.definePref_(
      'Emulate arrow keys with scroll wheel',
      hterm.PreferenceManager.categories.Scrolling,
      false, 'bool',
      `When using the alternative screen buffer, and DECCKM (Application ` +
      `Cursor Keys) is active, mouse wheel scroll events will emulate arrow ` +
      `keys.\n` +
      `\n` +
      `It can be temporarily disabled by holding the Shift key.\n` +
      `\n` +
      `This frequently comes up when using pagers (less) or reading man ` +
      `pages or text editors (vi/nano) or using screen/tmux.`
  ),

  'scroll-wheel-move-multiplier': hterm.PreferenceManager.definePref_(
      'Mouse scroll wheel multiplier',
      hterm.PreferenceManager.categories.Scrolling,
      1, 'int',
      `The multiplier for scroll wheel events when measured in pixels.\n` +
      `\n` +
      `Alters how fast the page scrolls.`
  ),

  'terminal-encoding': hterm.PreferenceManager.definePref_(
      'Terminal encoding',
      hterm.PreferenceManager.categories.Encoding,
      'utf-8', ['iso-2022', 'utf-8', 'utf-8-locked'],
      `The default terminal encoding (DOCS).\n` +
      `\n` +
      `ISO-2022 enables character map translations (like graphics maps).\n` +
      `UTF-8 disables support for those.\n` +
      `\n` +
      `The locked variant means the encoding cannot be changed at runtime ` +
      `via terminal escape sequences.\n` +
      `\n` +
      `You should stick with UTF-8 unless you notice broken rendering with ` +
      `legacy applications.`
  ),

  'shift-insert-paste': hterm.PreferenceManager.definePref_(
      'Shift-Insert paste',
      hterm.PreferenceManager.categories.Keyboard,
      true, 'bool',
      `Whether Shift-Insert is used for pasting or is sent to the remote host.`
  ),

  'user-css': hterm.PreferenceManager.definePref_(
      'Custom CSS (URI)',
      hterm.PreferenceManager.categories.Appearance,
      '', 'url',
      `URL of user stylesheet to include in the terminal document.`
  ),

  'user-css-text': hterm.PreferenceManager.definePref_(
      'Custom CSS (inline text)',
      hterm.PreferenceManager.categories.Appearance,
      '', 'multiline-string',
      `Custom CSS text for styling the terminal.`
  ),

  'allow-images-inline': hterm.PreferenceManager.definePref_(
      'Allow inline image display',
      hterm.PreferenceManager.categories.Extensions,
      null, 'tristate',
      `Whether to allow the remote host to display images in the terminal.\n` +
      `\n` +
      `By default, we prompt until a choice is made.`
  ),
};

hterm.PreferenceManager.prototype =
    Object.create(lib.PreferenceManager.prototype);
hterm.PreferenceManager.constructor = hterm.PreferenceManager;
// SOURCE FILE: hterm/js/hterm_pubsub.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

/**
 * Utility class used to add publish/subscribe/unsubscribe functionality to
 * an existing object.
 */
hterm.PubSub = function() {
  this.observers_ = {};
};

/**
 * Add publish, subscribe, and unsubscribe methods to an existing object.
 *
 * No other properties of the object are touched, so there is no need to
 * worry about clashing private properties.
 *
 * @param {Object} obj The object to add this behavior to.
 */
hterm.PubSub.addBehavior = function(obj) {
  var pubsub = new hterm.PubSub();
  for (var m in hterm.PubSub.prototype) {
    obj[m] = hterm.PubSub.prototype[m].bind(pubsub);
  }
};

/**
 * Subscribe to be notified of messages about a subject.
 *
 * @param {string} subject The subject to subscribe to.
 * @param {function(Object)} callback The function to invoke for notifications.
 */
hterm.PubSub.prototype.subscribe = function(subject, callback) {
  if (!(subject in this.observers_))
    this.observers_[subject] = [];

  this.observers_[subject].push(callback);
};

/**
 * Unsubscribe from a subject.
 *
 * @param {string} subject The subject to unsubscribe from.
 * @param {function(Object)} callback A callback previously registered via
 *     subscribe().
 */
hterm.PubSub.prototype.unsubscribe = function(subject, callback) {
  var list = this.observers_[subject];
  if (!list)
    throw 'Invalid subject: ' + subject;

  var i = list.indexOf(callback);
  if (i < 0)
    throw 'Not subscribed: ' + subject;

  list.splice(i, 1);
};

/**
 * Publish a message about a subject.
 *
 * Subscribers (and the optional final callback) are invoked asynchronously.
 * This method will return before anyone is actually notified.
 *
 * @param {string} subject The subject to publish about.
 * @param {Object} e An arbitrary object associated with this notification.
 * @param {function(Object)} opt_lastCallback An optional function to call after
 *     all subscribers have been notified.
 */
hterm.PubSub.prototype.publish = function(subject, e, opt_lastCallback) {
  function notifyList(i) {
    // Set this timeout before invoking the callback, so we don't have to
    // concern ourselves with exceptions.
    if (i < list.length - 1)
      setTimeout(notifyList, 0, i + 1);

    list[i](e);
  }

  var list = this.observers_[subject];
  if (list) {
    // Copy the list, in case it changes while we're notifying.
    list = [].concat(list);
  }

  if (opt_lastCallback) {
    if (list) {
      list.push(opt_lastCallback);
    } else {
      list = [opt_lastCallback];
    }
  }

  if (list)
    setTimeout(notifyList, 0, 0);
};
// SOURCE FILE: hterm/js/hterm_screen.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

lib.rtdep('lib.f', 'lib.wc',
          'hterm.RowCol', 'hterm.Size', 'hterm.TextAttributes');

/**
 * @fileoverview This class represents a single terminal screen full of text.
 *
 * It maintains the current cursor position and has basic methods for text
 * insert and overwrite, and adding or removing rows from the screen.
 *
 * This class has no knowledge of the scrollback buffer.
 *
 * The number of rows on the screen is determined only by the number of rows
 * that the caller inserts into the screen.  If a caller wants to ensure a
 * constant number of rows on the screen, it's their responsibility to remove a
 * row for each row inserted.
 *
 * The screen width, in contrast, is enforced locally.
 *
 *
 * In practice...
 * - The hterm.Terminal class holds two hterm.Screen instances.  One for the
 * primary screen and one for the alternate screen.
 *
 * - The html.Screen class only cares that rows are HTMLElements.  In the
 * larger context of hterm, however, the rows happen to be displayed by an
 * hterm.ScrollPort and have to follow a few rules as a result.  Each
 * row must be rooted by the custom HTML tag 'x-row', and each must have a
 * rowIndex property that corresponds to the index of the row in the context
 * of the scrollback buffer.  These invariants are enforced by hterm.Terminal
 * because that is the class using the hterm.Screen in the context of an
 * hterm.ScrollPort.
 */

/**
 * Create a new screen instance.
 *
 * The screen initially has no rows and a maximum column count of 0.
 *
 * @param {integer} opt_columnCount The maximum number of columns for this
 *    screen.  See insertString() and overwriteString() for information about
 *    what happens when too many characters are added too a row.  Defaults to
 *    0 if not provided.
 */
hterm.Screen = function(opt_columnCount) {
  /**
   * Public, read-only access to the rows in this screen.
   */
  this.rowsArray = [];

  // The max column width for this screen.
  this.columnCount_ = opt_columnCount || 80;

  // The current color, bold, underline and blink attributes.
  this.textAttributes = new hterm.TextAttributes(window.document);

  // Current zero-based cursor coordinates.
  this.cursorPosition = new hterm.RowCol(0, 0);

  // Saved state used by DECSC and related settings.  This is only for saving
  // and restoring specific state, not for the current/active state.
  this.cursorState_ = new hterm.Screen.CursorState(this);

  // The node containing the row that the cursor is positioned on.
  this.cursorRowNode_ = null;

  // The node containing the span of text that the cursor is positioned on.
  this.cursorNode_ = null;

  // The offset in column width into cursorNode_ where the cursor is positioned.
  this.cursorOffset_ = null;

  // Regexes for expanding word selections.
  this.wordBreakMatchLeft = null;
  this.wordBreakMatchRight = null;
  this.wordBreakMatchMiddle = null;
};

/**
 * Return the screen size as an hterm.Size object.
 *
 * @return {hterm.Size} hterm.Size object representing the current number
 *     of rows and columns in this screen.
 */
hterm.Screen.prototype.getSize = function() {
  return new hterm.Size(this.columnCount_, this.rowsArray.length);
};

/**
 * Return the current number of rows in this screen.
 *
 * @return {integer} The number of rows in this screen.
 */
hterm.Screen.prototype.getHeight = function() {
  return this.rowsArray.length;
};

/**
 * Return the current number of columns in this screen.
 *
 * @return {integer} The number of columns in this screen.
 */
hterm.Screen.prototype.getWidth = function() {
  return this.columnCount_;
};

/**
 * Set the maximum number of columns per row.
 *
 * @param {integer} count The maximum number of columns per row.
 */
hterm.Screen.prototype.setColumnCount = function(count) {
  this.columnCount_ = count;

  if (this.cursorPosition.column >= count)
    this.setCursorPosition(this.cursorPosition.row, count - 1);
};

/**
 * Remove the first row from the screen and return it.
 *
 * @return {HTMLElement} The first row in this screen.
 */
hterm.Screen.prototype.shiftRow = function() {
  return this.shiftRows(1)[0];
};

/**
 * Remove rows from the top of the screen and return them as an array.
 *
 * @param {integer} count The number of rows to remove.
 * @return {Array.<HTMLElement>} The selected rows.
 */
hterm.Screen.prototype.shiftRows = function(count) {
  return this.rowsArray.splice(0, count);
};

/**
 * Insert a row at the top of the screen.
 *
 * @param {HTMLElement} row The row to insert.
 */
hterm.Screen.prototype.unshiftRow = function(row) {
  this.rowsArray.splice(0, 0, row);
};

/**
 * Insert rows at the top of the screen.
 *
 * @param {Array.<HTMLElement>} rows The rows to insert.
 */
hterm.Screen.prototype.unshiftRows = function(rows) {
  this.rowsArray.unshift.apply(this.rowsArray, rows);
};

/**
 * Remove the last row from the screen and return it.
 *
 * @return {HTMLElement} The last row in this screen.
 */
hterm.Screen.prototype.popRow = function() {
  return this.popRows(1)[0];
};

/**
 * Remove rows from the bottom of the screen and return them as an array.
 *
 * @param {integer} count The number of rows to remove.
 * @return {Array.<HTMLElement>} The selected rows.
 */
hterm.Screen.prototype.popRows = function(count) {
  return this.rowsArray.splice(this.rowsArray.length - count, count);
};

/**
 * Insert a row at the bottom of the screen.
 *
 * @param {HTMLElement} row The row to insert.
 */
hterm.Screen.prototype.pushRow = function(row) {
  this.rowsArray.push(row);
};

/**
 * Insert rows at the bottom of the screen.
 *
 * @param {Array.<HTMLElement>} rows The rows to insert.
 */
hterm.Screen.prototype.pushRows = function(rows) {
  rows.push.apply(this.rowsArray, rows);
};

/**
 * Insert a row at the specified row of the screen.
 *
 * @param {integer} index The index to insert the row.
 * @param {HTMLElement} row The row to insert.
 */
hterm.Screen.prototype.insertRow = function(index, row) {
  this.rowsArray.splice(index, 0, row);
};

/**
 * Insert rows at the specified row of the screen.
 *
 * @param {integer} index The index to insert the rows.
 * @param {Array.<HTMLElement>} rows The rows to insert.
 */
hterm.Screen.prototype.insertRows = function(index, rows) {
  for (var i = 0; i < rows.length; i++) {
    this.rowsArray.splice(index + i, 0, rows[i]);
  }
};

/**
 * Remove a row from the screen and return it.
 *
 * @param {integer} index The index of the row to remove.
 * @return {HTMLElement} The selected row.
 */
hterm.Screen.prototype.removeRow = function(index) {
  return this.rowsArray.splice(index, 1)[0];
};

/**
 * Remove rows from the bottom of the screen and return them as an array.
 *
 * @param {integer} index The index to start removing rows.
 * @param {integer} count The number of rows to remove.
 * @return {Array.<HTMLElement>} The selected rows.
 */
hterm.Screen.prototype.removeRows = function(index, count) {
  return this.rowsArray.splice(index, count);
};

/**
 * Invalidate the current cursor position.
 *
 * This sets this.cursorPosition to (0, 0) and clears out some internal
 * data.
 *
 * Attempting to insert or overwrite text while the cursor position is invalid
 * will raise an obscure exception.
 */
hterm.Screen.prototype.invalidateCursorPosition = function() {
  this.cursorPosition.move(0, 0);
  this.cursorRowNode_ = null;
  this.cursorNode_ = null;
  this.cursorOffset_ = null;
};

/**
 * Clear the contents of the cursor row.
 */
hterm.Screen.prototype.clearCursorRow = function() {
  this.cursorRowNode_.innerHTML = '';
  this.cursorRowNode_.removeAttribute('line-overflow');
  this.cursorOffset_ = 0;
  this.cursorPosition.column = 0;
  this.cursorPosition.overflow = false;

  var text;
  if (this.textAttributes.isDefault()) {
    text = '';
  } else {
    text = lib.f.getWhitespace(this.columnCount_);
  }

  // We shouldn't honor inverse colors when clearing an area, to match
  // xterm's back color erase behavior.
  var inverse = this.textAttributes.inverse;
  this.textAttributes.inverse = false;
  this.textAttributes.syncColors();

  var node = this.textAttributes.createContainer(text);
  this.cursorRowNode_.appendChild(node);
  this.cursorNode_ = node;

  this.textAttributes.inverse = inverse;
  this.textAttributes.syncColors();
};

/**
 * Mark the current row as having overflowed to the next line.
 *
 * The line overflow state is used when converting a range of rows into text.
 * It makes it possible to recombine two or more overflow terminal rows into
 * a single line.
 *
 * This is distinct from the cursor being in the overflow state.  Cursor
 * overflow indicates that printing at the cursor position will commit a
 * line overflow, unless it is preceded by a repositioning of the cursor
 * to a non-overflow state.
 */
hterm.Screen.prototype.commitLineOverflow = function() {
  this.cursorRowNode_.setAttribute('line-overflow', true);
};

/**
 * Relocate the cursor to a give row and column.
 *
 * @param {integer} row The zero based row.
 * @param {integer} column The zero based column.
 */
hterm.Screen.prototype.setCursorPosition = function(row, column) {
  if (!this.rowsArray.length) {
    console.warn('Attempt to set cursor position on empty screen.');
    return;
  }

  if (row >= this.rowsArray.length) {
    console.error('Row out of bounds: ' + row);
    row = this.rowsArray.length - 1;
  } else if (row < 0) {
    console.error('Row out of bounds: ' + row);
    row = 0;
  }

  if (column >= this.columnCount_) {
    console.error('Column out of bounds: ' + column);
    column = this.columnCount_ - 1;
  } else if (column < 0) {
    console.error('Column out of bounds: ' + column);
    column = 0;
  }

  this.cursorPosition.overflow = false;

  var rowNode = this.rowsArray[row];
  var node = rowNode.firstChild;

  if (!node) {
    node = rowNode.ownerDocument.createTextNode('');
    rowNode.appendChild(node);
  }

  var currentColumn = 0;

  if (rowNode == this.cursorRowNode_) {
    if (column >= this.cursorPosition.column - this.cursorOffset_) {
      node = this.cursorNode_;
      currentColumn = this.cursorPosition.column - this.cursorOffset_;
    }
  } else {
    this.cursorRowNode_ = rowNode;
  }

  this.cursorPosition.move(row, column);

  while (node) {
    var offset = column - currentColumn;
    var width = hterm.TextAttributes.nodeWidth(node);
    if (!node.nextSibling || width > offset) {
      this.cursorNode_ = node;
      this.cursorOffset_ = offset;
      return;
    }

    currentColumn += width;
    node = node.nextSibling;
  }
};

/**
 * Set the provided selection object to be a caret selection at the current
 * cursor position.
 */
hterm.Screen.prototype.syncSelectionCaret = function(selection) {
  try {
    selection.collapse(this.cursorNode_, this.cursorOffset_);
  } catch (firefoxIgnoredException) {
    // FF can throw an exception if the range is off, rather than just not
    // performing the collapse.
  }
};

/**
 * Split a single node into two nodes at the given offset.
 *
 * For example:
 * Given the DOM fragment '<div><span>Hello World</span></div>', call splitNode_
 * passing the span and an offset of 6.  This would modify the fragment to
 * become: '<div><span>Hello </span><span>World</span></div>'.  If the span
 * had any attributes they would have been copied to the new span as well.
 *
 * The to-be-split node must have a container, so that the new node can be
 * placed next to it.
 *
 * @param {HTMLNode} node The node to split.
 * @param {integer} offset The offset into the node where the split should
 *     occur.
 */
hterm.Screen.prototype.splitNode_ = function(node, offset) {
  var afterNode = node.cloneNode(false);

  var textContent = node.textContent;
  node.textContent = hterm.TextAttributes.nodeSubstr(node, 0, offset);
  afterNode.textContent = lib.wc.substr(textContent, offset);

  if (afterNode.textContent)
    node.parentNode.insertBefore(afterNode, node.nextSibling);
  if (!node.textContent)
    node.parentNode.removeChild(node);
};

/**
 * Ensure that text is clipped and the cursor is clamped to the column count.
 */
hterm.Screen.prototype.maybeClipCurrentRow = function() {
  var width = hterm.TextAttributes.nodeWidth(this.cursorRowNode_);

  if (width <= this.columnCount_) {
    // Current row does not need clipping, but may need clamping.
    if (this.cursorPosition.column >= this.columnCount_) {
      this.setCursorPosition(this.cursorPosition.row, this.columnCount_ - 1);
      this.cursorPosition.overflow = true;
    }

    return;
  }

  // Save off the current column so we can maybe restore it later.
  var currentColumn = this.cursorPosition.column;

  // Move the cursor to the final column.
  this.setCursorPosition(this.cursorPosition.row, this.columnCount_ - 1);

  // Remove any text that partially overflows.
  width = hterm.TextAttributes.nodeWidth(this.cursorNode_);

  if (this.cursorOffset_ < width - 1) {
    this.cursorNode_.textContent = hterm.TextAttributes.nodeSubstr(
        this.cursorNode_, 0, this.cursorOffset_ + 1);
  }

  // Remove all nodes after the cursor.
  var rowNode = this.cursorRowNode_;
  var node = this.cursorNode_.nextSibling;

  while (node) {
    rowNode.removeChild(node);
    node = this.cursorNode_.nextSibling;
  }

  if (currentColumn < this.columnCount_) {
    // If the cursor was within the screen before we started then restore its
    // position.
    this.setCursorPosition(this.cursorPosition.row, currentColumn);
  } else {
    // Otherwise leave it at the the last column in the overflow state.
    this.cursorPosition.overflow = true;
  }
};

/**
 * Insert a string at the current character position using the current
 * text attributes.
 *
 * You must call maybeClipCurrentRow() after in order to clip overflowed
 * text and clamp the cursor.
 *
 * It is also up to the caller to properly maintain the line overflow state
 * using hterm.Screen..commitLineOverflow().
 */
hterm.Screen.prototype.insertString = function(str, wcwidth=undefined) {
  var cursorNode = this.cursorNode_;
  var cursorNodeText = cursorNode.textContent;

  this.cursorRowNode_.removeAttribute('line-overflow');

  // We may alter the width of the string by prepending some missing
  // whitespaces, so we need to record the string width ahead of time.
  if (wcwidth === undefined)
    wcwidth = lib.wc.strWidth(str);

  // No matter what, before this function exits the cursor column will have
  // moved this much.
  this.cursorPosition.column += wcwidth;

  // Local cache of the cursor offset.
  var offset = this.cursorOffset_;

  // Reverse offset is the offset measured from the end of the string.
  // Zero implies that the cursor is at the end of the cursor node.
  var reverseOffset = hterm.TextAttributes.nodeWidth(cursorNode) - offset;

  if (reverseOffset < 0) {
    // A negative reverse offset means the cursor is positioned past the end
    // of the characters on this line.  We'll need to insert the missing
    // whitespace.
    var ws = lib.f.getWhitespace(-reverseOffset);

    // This whitespace should be completely unstyled.  Underline, background
    // color, and strikethrough would be visible on whitespace, so we can't use
    // one of those spans to hold the text.
    if (!(this.textAttributes.underline ||
          this.textAttributes.strikethrough ||
          this.textAttributes.background ||
          this.textAttributes.wcNode ||
          !this.textAttributes.asciiNode ||
          this.textAttributes.tileData != null)) {
      // Best case scenario, we can just pretend the spaces were part of the
      // original string.
      str = ws + str;
    } else if (cursorNode.nodeType == Node.TEXT_NODE ||
               !(cursorNode.wcNode ||
                 !cursorNode.asciiNode ||
                 cursorNode.tileNode ||
                 cursorNode.style.textDecoration ||
                 cursorNode.style.textDecorationStyle ||
                 cursorNode.style.textDecorationLine ||
                 cursorNode.style.backgroundColor)) {
      // Second best case, the current node is able to hold the whitespace.
      cursorNode.textContent = (cursorNodeText += ws);
    } else {
      // Worst case, we have to create a new node to hold the whitespace.
      var wsNode = cursorNode.ownerDocument.createTextNode(ws);
      this.cursorRowNode_.insertBefore(wsNode, cursorNode.nextSibling);
      this.cursorNode_ = cursorNode = wsNode;
      this.cursorOffset_ = offset = -reverseOffset;
      cursorNodeText = ws;
    }

    // We now know for sure that we're at the last character of the cursor node.
    reverseOffset = 0;
  }

  if (this.textAttributes.matchesContainer(cursorNode)) {
    // The new text can be placed directly in the cursor node.
    if (reverseOffset == 0) {
      cursorNode.textContent = cursorNodeText + str;
    } else if (offset == 0) {
      cursorNode.textContent = str + cursorNodeText;
    } else {
      cursorNode.textContent =
          hterm.TextAttributes.nodeSubstr(cursorNode, 0, offset) +
          str + hterm.TextAttributes.nodeSubstr(cursorNode, offset);
    }

    this.cursorOffset_ += wcwidth;
    return;
  }

  // The cursor node is the wrong style for the new text.  If we're at the
  // beginning or end of the cursor node, then the adjacent node is also a
  // potential candidate.

  if (offset == 0) {
    // At the beginning of the cursor node, the check the previous sibling.
    var previousSibling = cursorNode.previousSibling;
    if (previousSibling &&
        this.textAttributes.matchesContainer(previousSibling)) {
      previousSibling.textContent += str;
      this.cursorNode_ = previousSibling;
      this.cursorOffset_ = lib.wc.strWidth(previousSibling.textContent);
      return;
    }

    var newNode = this.textAttributes.createContainer(str);
    this.cursorRowNode_.insertBefore(newNode, cursorNode);
    this.cursorNode_ = newNode;
    this.cursorOffset_ = wcwidth;
    return;
  }

  if (reverseOffset == 0) {
    // At the end of the cursor node, the check the next sibling.
    var nextSibling = cursorNode.nextSibling;
    if (nextSibling &&
        this.textAttributes.matchesContainer(nextSibling)) {
      nextSibling.textContent = str + nextSibling.textContent;
      this.cursorNode_ = nextSibling;
      this.cursorOffset_ = lib.wc.strWidth(str);
      return;
    }

    var newNode = this.textAttributes.createContainer(str);
    this.cursorRowNode_.insertBefore(newNode, nextSibling);
    this.cursorNode_ = newNode;
    // We specifically need to include any missing whitespace here, since it's
    // going in a new node.
    this.cursorOffset_ = hterm.TextAttributes.nodeWidth(newNode);
    return;
  }

  // Worst case, we're somewhere in the middle of the cursor node.  We'll
  // have to split it into two nodes and insert our new container in between.
  this.splitNode_(cursorNode, offset);
  var newNode = this.textAttributes.createContainer(str);
  this.cursorRowNode_.insertBefore(newNode, cursorNode.nextSibling);
  this.cursorNode_ = newNode;
  this.cursorOffset_ = wcwidth;
};

/**
 * Overwrite the text at the current cursor position.
 *
 * You must call maybeClipCurrentRow() after in order to clip overflowed
 * text and clamp the cursor.
 *
 * It is also up to the caller to properly maintain the line overflow state
 * using hterm.Screen..commitLineOverflow().
 */
hterm.Screen.prototype.overwriteString = function(str, wcwidth=undefined) {
  var maxLength = this.columnCount_ - this.cursorPosition.column;
  if (!maxLength)
    return [str];

  if (wcwidth === undefined)
    wcwidth = lib.wc.strWidth(str);

  if (this.textAttributes.matchesContainer(this.cursorNode_) &&
      this.cursorNode_.textContent.substr(this.cursorOffset_) == str) {
    // This overwrite would be a no-op, just move the cursor and return.
    this.cursorOffset_ += wcwidth;
    this.cursorPosition.column += wcwidth;
    return;
  }

  this.deleteChars(Math.min(wcwidth, maxLength));
  this.insertString(str, wcwidth);
};

/**
 * Forward-delete one or more characters at the current cursor position.
 *
 * Text to the right of the deleted characters is shifted left.  Only affects
 * characters on the same row as the cursor.
 *
 * @param {integer} count The column width of characters to delete.  This is
 *     clamped to the column width minus the cursor column.
 * @return {integer} The column width of the characters actually deleted.
 */
hterm.Screen.prototype.deleteChars = function(count) {
  var node = this.cursorNode_;
  var offset = this.cursorOffset_;

  var currentCursorColumn = this.cursorPosition.column;
  count = Math.min(count, this.columnCount_ - currentCursorColumn);
  if (!count)
    return 0;

  var rv = count;
  var startLength, endLength;

  while (node && count) {
    // Sanity check so we don't loop forever, but we don't also go quietly.
    if (count < 0) {
      console.error(`Deleting ${rv} chars went negative: ${count}`);
      break;
    }

    startLength = hterm.TextAttributes.nodeWidth(node);
    node.textContent = hterm.TextAttributes.nodeSubstr(node, 0, offset) +
        hterm.TextAttributes.nodeSubstr(node, offset + count);
    endLength = hterm.TextAttributes.nodeWidth(node);

    // Deal with splitting wide characters.  There are two ways: we could delete
    // the first column or the second column.  In both cases, we delete the wide
    // character and replace one of the columns with a space (since the other
    // was deleted).  If there are more chars to delete, the next loop will pick
    // up the slack.
    if (node.wcNode && offset < startLength &&
        ((endLength && startLength == endLength) || (!endLength && offset == 1))) {
      // No characters were deleted when there should be.  We're probably trying
      // to delete one column width from a wide character node.  We remove the
      // wide character node here and replace it with a single space.
      var spaceNode = this.textAttributes.createContainer(' ');
      node.parentNode.insertBefore(spaceNode, offset ? node : node.nextSibling);
      node.textContent = '';
      endLength = 0;
      count -= 1;
    } else
      count -= startLength - endLength;

    var nextNode = node.nextSibling;
    if (endLength == 0 && node != this.cursorNode_) {
      node.parentNode.removeChild(node);
    }
    node = nextNode;
    offset = 0;
  }

  // Remove this.cursorNode_ if it is an empty non-text node.
  if (this.cursorNode_.nodeType != Node.TEXT_NODE &&
      !this.cursorNode_.textContent) {
    var cursorNode = this.cursorNode_;
    if (cursorNode.previousSibling) {
      this.cursorNode_ = cursorNode.previousSibling;
      this.cursorOffset_ = hterm.TextAttributes.nodeWidth(
          cursorNode.previousSibling);
    } else if (cursorNode.nextSibling) {
      this.cursorNode_ = cursorNode.nextSibling;
      this.cursorOffset_ = 0;
    } else {
      var emptyNode = this.cursorRowNode_.ownerDocument.createTextNode('');
      this.cursorRowNode_.appendChild(emptyNode);
      this.cursorNode_ = emptyNode;
      this.cursorOffset_ = 0;
    }
    this.cursorRowNode_.removeChild(cursorNode);
  }

  return rv;
};

/**
 * Finds first X-ROW of a line containing specified X-ROW.
 * Used to support line overflow.
 *
 * @param {Node} row X-ROW to begin search for first row of line.
 * @return {Node} The X-ROW that is at the beginning of the line.
 **/
hterm.Screen.prototype.getLineStartRow_ = function(row) {
  while (row.previousSibling &&
         row.previousSibling.hasAttribute('line-overflow')) {
    row = row.previousSibling;
  }
  return row;
};

/**
 * Gets text of a line beginning with row.
 * Supports line overflow.
 *
 * @param {Node} row First X-ROW of line.
 * @return {string} Text content of line.
 **/
hterm.Screen.prototype.getLineText_ = function(row) {
  var rowText = "";
  while (row) {
    rowText += row.textContent;
    if (row.hasAttribute('line-overflow')) {
      row = row.nextSibling;
    } else {
      break;
    }
  }
  return rowText;
};

/**
 * Returns X-ROW that is ancestor of the node.
 *
 * @param {Node} node Node to get X-ROW ancestor for.
 * @return {Node} X-ROW ancestor of node, or null if not found.
 **/
hterm.Screen.prototype.getXRowAncestor_ = function(node) {
  while (node) {
    if (node.nodeName === 'X-ROW')
      break;
    node = node.parentNode;
  }
  return node;
};

/**
 * Returns position within line of character at offset within node.
 * Supports line overflow.
 *
 * @param {Node} row X-ROW at beginning of line.
 * @param {Node} node Node to get position of.
 * @param {integer} offset Offset into node.
 *
 * @return {integer} Position within line of character at offset within node.
 **/
hterm.Screen.prototype.getPositionWithOverflow_ = function(row, node, offset) {
  if (!node)
    return -1;
  var ancestorRow = this.getXRowAncestor_(node);
  if (!ancestorRow)
    return -1;
  var position = 0;
  while (ancestorRow != row) {
    position += hterm.TextAttributes.nodeWidth(row);
    if (row.hasAttribute('line-overflow') && row.nextSibling) {
      row = row.nextSibling;
    } else {
      return -1;
    }
  }
  return position + this.getPositionWithinRow_(row, node, offset);
};

/**
 * Returns position within row of character at offset within node.
 * Does not support line overflow.
 *
 * @param {Node} row X-ROW to get position within.
 * @param {Node} node Node to get position for.
 * @param {integer} offset Offset within node to get position for.
 * @return {integer} Position within row of character at offset within node.
 **/
hterm.Screen.prototype.getPositionWithinRow_ = function(row, node, offset) {
  if (node.parentNode != row) {
    // If we traversed to the top node, then there's nothing to find here.
    if (node.parentNode == null)
      return -1;

    return this.getPositionWithinRow_(node.parentNode, node, offset) +
           this.getPositionWithinRow_(row, node.parentNode, 0);
  }
  var position = 0;
  for (var i = 0; i < row.childNodes.length; i++) {
    var currentNode = row.childNodes[i];
    if (currentNode == node)
      return position + offset;
    position += hterm.TextAttributes.nodeWidth(currentNode);
  }
  return -1;
};

/**
 * Returns the node and offset corresponding to position within line.
 * Supports line overflow.
 *
 * @param {Node} row X-ROW at beginning of line.
 * @param {integer} position Position within line to retrieve node and offset.
 * @return {Array} Two element array containing node and offset respectively.
 **/
hterm.Screen.prototype.getNodeAndOffsetWithOverflow_ = function(row, position) {
  while (row && position > hterm.TextAttributes.nodeWidth(row)) {
    if (row.hasAttribute('line-overflow') && row.nextSibling) {
      position -= hterm.TextAttributes.nodeWidth(row);
      row = row.nextSibling;
    } else {
      return -1;
    }
  }
  return this.getNodeAndOffsetWithinRow_(row, position);
};

/**
 * Returns the node and offset corresponding to position within row.
 * Does not support line overflow.
 *
 * @param {Node} row X-ROW to get position within.
 * @param {integer} position Position within row to retrieve node and offset.
 * @return {Array} Two element array containing node and offset respectively.
 **/
hterm.Screen.prototype.getNodeAndOffsetWithinRow_ = function(row, position) {
  for (var i = 0; i < row.childNodes.length; i++) {
    var node = row.childNodes[i];
    var nodeTextWidth = hterm.TextAttributes.nodeWidth(node);
    if (position <= nodeTextWidth) {
      if (node.nodeName === 'SPAN') {
        /** Drill down to node contained by SPAN. **/
        return this.getNodeAndOffsetWithinRow_(node, position);
      } else {
        return [node, position];
      }
    }
    position -= nodeTextWidth;
  }
  return null;
};

/**
 * Returns the node and offset corresponding to position within line.
 * Supports line overflow.
 *
 * @param {Node} row X-ROW at beginning of line.
 * @param {integer} start Start position of range within line.
 * @param {integer} end End position of range within line.
 * @param {Range} range Range to modify.
 **/
hterm.Screen.prototype.setRange_ = function(row, start, end, range) {
  var startNodeAndOffset = this.getNodeAndOffsetWithOverflow_(row, start);
  if (startNodeAndOffset == null)
    return;
  var endNodeAndOffset = this.getNodeAndOffsetWithOverflow_(row, end);
  if (endNodeAndOffset == null)
    return;
  range.setStart(startNodeAndOffset[0], startNodeAndOffset[1]);
  range.setEnd(endNodeAndOffset[0], endNodeAndOffset[1]);
};

/**
 * Expands selection to surrounding string with word break matches.
 *
 * @param {Selection} selection Selection to expand.
 * @param {string} leftMatch left word break match.
 * @param {string} rightMatch right word break match.
 * @param {string} insideMatch inside word break match.
 */
hterm.Screen.prototype.expandSelectionWithWordBreakMatches_ =
    function(selection, leftMatch, rightMatch, insideMatch) {
  if (!selection)
    return;

  var range = selection.getRangeAt(0);
  if (!range || range.toString().match(/\s/))
    return;

  const rowElement = this.getXRowAncestor_(range.startContainer);
  if (!rowElement)
    return;
  const row = this.getLineStartRow_(rowElement);
  if (!row)
    return;

  var startPosition = this.getPositionWithOverflow_(row,
                                                    range.startContainer,
                                                    range.startOffset);
  if (startPosition == -1)
    return;
  var endPosition = this.getPositionWithOverflow_(row,
                                                  range.endContainer,
                                                  range.endOffset);
  if (endPosition == -1)
    return;

  //Move start to the left.
  var rowText = this.getLineText_(row);
  var lineUpToRange = lib.wc.substring(rowText, 0, endPosition);
  var leftRegularExpression = new RegExp(leftMatch + insideMatch + "$");
  var expandedStart = lineUpToRange.search(leftRegularExpression);
  if (expandedStart == -1 || expandedStart > startPosition)
    return;

  //Move end to the right.
  var lineFromRange = lib.wc.substring(rowText, startPosition,
                                       lib.wc.strWidth(rowText));
  var rightRegularExpression = new RegExp("^" + insideMatch + rightMatch);
  var found = lineFromRange.match(rightRegularExpression);
  if (!found)
    return;
  var expandedEnd = startPosition + lib.wc.strWidth(found[0]);
  if (expandedEnd == -1 || expandedEnd < endPosition)
    return;

  this.setRange_(row, expandedStart, expandedEnd, range);
  selection.addRange(range);
};

/**
 * Expands selection to surrounding string using the user's settings.
 *
 * @param {Selection} selection Selection to expand.
 */
hterm.Screen.prototype.expandSelection = function(selection) {
  this.expandSelectionWithWordBreakMatches_(
      selection,
      this.wordBreakMatchLeft,
      this.wordBreakMatchRight,
      this.wordBreakMatchMiddle);
};

/**
 * Expands selection to surrounding URL using a set of fixed match settings.
 *
 * @param {Selection} selection Selection to expand.
 */
hterm.Screen.prototype.expandSelectionForUrl = function(selection) {
  this.expandSelectionWithWordBreakMatches_(
      selection,
      "[^\\s\\[\\](){}<>\"'\\^!@#$%&*,;:`]",
      "[^\\s\\[\\](){}<>\"'\\^!@#$%&*,;:~.`]",
      "[^\\s\\[\\](){}<>\"'\\^]*");
};

/**
 * Save the current cursor state to the corresponding screens.
 *
 * @param {hterm.VT} vt The VT object to read graphic codeset details from.
 */
hterm.Screen.prototype.saveCursorAndState = function(vt) {
  this.cursorState_.save(vt);
};

/**
 * Restore the saved cursor state in the corresponding screens.
 *
 * @param {hterm.VT} vt The VT object to write graphic codeset details to.
 */
hterm.Screen.prototype.restoreCursorAndState = function(vt) {
  this.cursorState_.restore(vt);
};

/**
 * Track all the things related to the current "cursor".
 *
 * The set of things saved & restored here is defined by DEC:
 * https://vt100.net/docs/vt510-rm/DECSC.html
 * - Cursor position
 * - Character attributes set by the SGR command
 * - Character sets (G0, G1, G2, or G3) currently in GL and GR
 * - Wrap flag (autowrap or no autowrap)
 * - State of origin mode (DECOM)
 * - Selective erase attribute
 * - Any single shift 2 (SS2) or single shift 3 (SS3) functions sent
 *
 * These are done on a per-screen basis.
 */
hterm.Screen.CursorState = function(screen) {
  this.screen_ = screen;
  this.cursor = null;
  this.textAttributes = null;
  this.GL = this.GR = this.G0 = this.G1 = this.G2 = this.G3 = null;
};

/**
 * Save all the cursor state.
 *
 * @param {hterm.VT} vt The VT object to read graphic codeset details from.
 */
hterm.Screen.CursorState.prototype.save = function(vt) {
  this.cursor = vt.terminal.saveCursor();

  this.textAttributes = this.screen_.textAttributes.clone();

  this.GL = vt.GL;
  this.GR = vt.GR;

  this.G0 = vt.G0;
  this.G1 = vt.G1;
  this.G2 = vt.G2;
  this.G3 = vt.G3;
};

/**
 * Restore the previously saved cursor state.
 *
 * @param {hterm.VT} vt The VT object to write graphic codeset details to.
 */
hterm.Screen.CursorState.prototype.restore = function(vt) {
  vt.terminal.restoreCursor(this.cursor);

  // Cursor restore includes char attributes (bold/etc...), but does not change
  // the color palette (which are a terminal setting).
  const tattrs = this.textAttributes.clone();
  tattrs.colorPalette = this.screen_.textAttributes.colorPalette;
  tattrs.syncColors();

  this.screen_.textAttributes = tattrs;

  vt.GL = this.GL;
  vt.GR = this.GR;

  vt.G0 = this.G0;
  vt.G1 = this.G1;
  vt.G2 = this.G2;
  vt.G3 = this.G3;
};
// SOURCE FILE: hterm/js/hterm_scrollport.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

lib.rtdep('lib.f', 'hterm.PubSub', 'hterm.Size');

/**
 * A 'viewport' view of fixed-height rows with support for selection and
 * copy-to-clipboard.
 *
 * 'Viewport' in this case means that only the visible rows are in the DOM.
 * If the rowProvider has 100,000 rows, but the ScrollPort is only 25 rows
 * tall, then only 25 dom nodes are created.  The ScrollPort will ask the
 * RowProvider to create new visible rows on demand as they are scrolled in
 * to the visible area.
 *
 * This viewport is designed so that select and copy-to-clipboard still works,
 * even when all or part of the selection is scrolled off screen.
 *
 * Note that the X11 mouse clipboard does not work properly when all or part
 * of the selection is off screen.  It would be difficult to fix this without
 * adding significant overhead to pathologically large selection cases.
 *
 * The RowProvider should return rows rooted by the custom tag name 'x-row'.
 * This ensures that we can quickly assign the correct display height
 * to the rows with css.
 *
 * @param {RowProvider} rowProvider An object capable of providing rows as
 *     raw text or row nodes.
 */
hterm.ScrollPort = function(rowProvider) {
  hterm.PubSub.addBehavior(this);

  this.rowProvider_ = rowProvider;

  // SWAG the character size until we can measure it.
  this.characterSize = new hterm.Size(10, 10);

  // DOM node used for character measurement.
  this.ruler_ = null;

  this.selection = new hterm.ScrollPort.Selection(this);

  // A map of rowIndex => rowNode for each row that is drawn as part of a
  // pending redraw_() call.  Null if there is no pending redraw_ call.
  this.currentRowNodeCache_ = null;

  // A map of rowIndex => rowNode for each row that was drawn as part of the
  // previous redraw_() call.
  this.previousRowNodeCache_ = {};

  // Used during scroll events to detect when the underlying cause is a resize.
  this.lastScreenWidth_ = null;
  this.lastScreenHeight_ = null;

  // True if the user should be allowed to select text in the terminal.
  // This is disabled when the host requests mouse drag events so that we don't
  // end up with two notions of selection.
  this.selectionEnabled_ = true;

  // The last row count returned by the row provider, re-populated during
  // syncScrollHeight().
  this.lastRowCount_ = 0;

  // The scroll wheel pixel delta multiplier to increase/decrease
  // the scroll speed of mouse wheel events. See: https://goo.gl/sXelnq
  this.scrollWheelMultiplier_ = 1;

  // The last touch events we saw to support touch based scrolling.  Indexed
  // by touch identifier since we can have more than one touch active.
  this.lastTouch_ = {};

  /**
   * True if the last scroll caused the scrollport to show the final row.
   */
  this.isScrolledEnd = true;

  /**
   * A guess at the current scrollbar width, fixed in resize().
   */
  this.currentScrollbarWidthPx = 16;

  /**
   * Whether the ctrl-v key on the screen should paste.
   */
  this.ctrlVPaste = false;

  /**
   * Whether to paste on dropped text.
   */
  this.pasteOnDrop = true;

  this.div_ = null;
  this.document_ = null;

  // Collection of active timeout handles.
  this.timeouts_ = {};

  this.observers_ = {};

  this.DEBUG_ = false;
};

/**
 * Proxy for the native selection object which understands how to walk up the
 * DOM to find the containing row node and sort out which comes first.
 *
 * @param {hterm.ScrollPort} scrollPort The parent hterm.ScrollPort instance.
 */
hterm.ScrollPort.Selection = function(scrollPort) {
  this.scrollPort_ = scrollPort;

  /**
   * The row containing the start of the selection.
   *
   * This may be partially or fully selected.  It may be the selection anchor
   * or the focus, but its rowIndex is guaranteed to be less-than-or-equal-to
   * that of the endRow.
   *
   * If only one row is selected then startRow == endRow.  If there is no
   * selection or the selection is collapsed then startRow == null.
   */
  this.startRow = null;

  /**
   * The row containing the end of the selection.
   *
   * This may be partially or fully selected.  It may be the selection anchor
   * or the focus, but its rowIndex is guaranteed to be greater-than-or-equal-to
   * that of the startRow.
   *
   * If only one row is selected then startRow == endRow.  If there is no
   * selection or the selection is collapsed then startRow == null.
   */
  this.endRow = null;

  /**
   * True if startRow != endRow.
   */
  this.isMultiline = null;

  /**
   * True if the selection is just a point rather than a range.
   */
  this.isCollapsed = null;
};

/**
 * Given a list of DOM nodes and a container, return the DOM node that
 * is first according to a depth-first search.
 *
 * Returns null if none of the children are found.
 */
hterm.ScrollPort.Selection.prototype.findFirstChild = function(
    parent, childAry) {
  var node = parent.firstChild;

  while (node) {
    if (childAry.indexOf(node) != -1)
      return node;

    if (node.childNodes.length) {
      var rv = this.findFirstChild(node, childAry);
      if (rv)
        return rv;
    }

    node = node.nextSibling;
  }

  return null;
};

/**
 * Synchronize this object with the current DOM selection.
 *
 * This is a one-way synchronization, the DOM selection is copied to this
 * object, not the other way around.
 */
hterm.ScrollPort.Selection.prototype.sync = function() {
  var self = this;

  // The dom selection object has no way to tell which nodes come first in
  // the document, so we have to figure that out.
  //
  // This function is used when we detect that the "anchor" node is first.
  function anchorFirst() {
    self.startRow = anchorRow;
    self.startNode = selection.anchorNode;
    self.startOffset = selection.anchorOffset;
    self.endRow = focusRow;
    self.endNode = selection.focusNode;
    self.endOffset = selection.focusOffset;
  }

  // This function is used when we detect that the "focus" node is first.
  function focusFirst() {
    self.startRow = focusRow;
    self.startNode = selection.focusNode;
    self.startOffset = selection.focusOffset;
    self.endRow = anchorRow;
    self.endNode = selection.anchorNode;
    self.endOffset = selection.anchorOffset;
  }

  var selection = this.scrollPort_.getDocument().getSelection();

  this.startRow = null;
  this.endRow = null;
  this.isMultiline = null;
  this.isCollapsed = !selection || selection.isCollapsed;

  if (!selection) {
    return;
  }

  // Usually collapsed selections wouldn't be interesting, however screen
  // readers will set a collapsed selection as they navigate through the DOM.
  // It is important to preserve these nodes in the DOM as scrolling happens
  // so that screen reader navigation isn't cleared.
  const accessibilityEnabled = this.scrollPort_.accessibilityReader_ &&
      this.scrollPort_.accessibilityReader_.accessibilityEnabled;
  if (this.isCollapsed && !accessibilityEnabled) {
    return;
  }

  var anchorRow = selection.anchorNode;
  while (anchorRow && anchorRow.nodeName != 'X-ROW') {
    anchorRow = anchorRow.parentNode;
  }

  if (!anchorRow) {
    // Don't set a selection if it's not a row node that's selected.
    return;
  }

  var focusRow = selection.focusNode;
  while (focusRow && focusRow.nodeName != 'X-ROW') {
    focusRow = focusRow.parentNode;
  }

  if (!focusRow) {
    // Don't set a selection if it's not a row node that's selected.
    return;
  }

  if (anchorRow.rowIndex < focusRow.rowIndex) {
    anchorFirst();

  } else if (anchorRow.rowIndex > focusRow.rowIndex) {
    focusFirst();

  } else if (selection.focusNode == selection.anchorNode) {
    if (selection.anchorOffset < selection.focusOffset) {
      anchorFirst();
    } else {
      focusFirst();
    }

  } else {
    // The selection starts and ends in the same row, but isn't contained all
    // in a single node.
    var firstNode = this.findFirstChild(
        anchorRow, [selection.anchorNode, selection.focusNode]);

    if (!firstNode)
      throw new Error('Unexpected error syncing selection.');

    if (firstNode == selection.anchorNode) {
      anchorFirst();
    } else {
      focusFirst();
    }
  }

  this.isMultiline = anchorRow.rowIndex != focusRow.rowIndex;
};


/**
 * Turn a div into this hterm.ScrollPort.
 */
hterm.ScrollPort.prototype.decorate = function(div) {
  this.div_ = div;

  this.iframe_ = div.ownerDocument.createElement('iframe');
  this.iframe_.style.cssText = (
      'border: 0;' +
      'height: 100%;' +
      'position: absolute;' +
      'width: 100%');

  // Set the iframe src to # in FF.  Otherwise when the frame's
  // load event fires in FF it clears out the content of the iframe.
  if ('mozInnerScreenX' in window)  // detect a FF only property
    this.iframe_.src = '#';

  div.appendChild(this.iframe_);

  this.iframe_.contentWindow.addEventListener('resize',
                                              this.onResize_.bind(this));

  var doc = this.document_ = this.iframe_.contentDocument;
  doc.body.style.cssText = (
      'margin: 0px;' +
      'padding: 0px;' +
      'height: 100%;' +
      'width: 100%;' +
      'overflow: hidden;' +
      'cursor: var(--hterm-mouse-cursor-style);' +
      '-webkit-user-select: none;' +
      '-moz-user-select: none;');

  const metaCharset = doc.createElement('meta');
  metaCharset.setAttribute('charset', 'utf-8');
  doc.head.appendChild(metaCharset);

  if (this.DEBUG_) {
    // When we're debugging we add padding to the body so that the offscreen
    // elements are visible.
    this.document_.body.style.paddingTop =
        this.document_.body.style.paddingBottom =
        'calc(var(--hterm-charsize-height) * 3)';
  }

  var style = doc.createElement('style');

  // Hide rows that are above or below the x-fold elements. This is necessary to
  // ensure that these rows aren't visible to a screen reader. First hide all
  // rows that are children of the <x-screen>. Then display the nodes that are
  // after the top fold. Then rehide nodes that are after the bottom fold.
  style.textContent = `
      x-row {
        display: block;
        height: var(--hterm-charsize-height);
        line-height: var(--hterm-charsize-height);
      }

      x-screen x-row {
        visibility: hidden;
      }

      #hterm\\:top-fold-for-row-selection ~ x-row {
        visibility: visible;
      }

      #hterm\\:bottom-fold-for-row-selection ~ x-row {
        visibility: hidden;
      }`;
  doc.head.appendChild(style);

  this.userCssLink_ = doc.createElement('link');
  this.userCssLink_.setAttribute('rel', 'stylesheet');

  this.userCssText_ = doc.createElement('style');
  doc.head.appendChild(this.userCssText_);

  // TODO(rginda): Sorry, this 'screen_' isn't the same thing as hterm.Screen
  // from screen.js.  I need to pick a better name for one of them to avoid
  // the collision.
  // We make this field editable even though we don't actually allow anything
  // to be edited here so that Chrome will do the right thing with virtual
  // keyboards and IMEs.  But make sure we turn off all the input helper logic
  // that doesn't make sense here, and might inadvertently mung or save input.
  // Some of these attributes are standard while others are browser specific,
  // but should be safely ignored by other browsers.
  this.screen_ = doc.createElement('x-screen');
  this.screen_.setAttribute('contenteditable', 'true');
  this.screen_.setAttribute('spellcheck', 'false');
  this.screen_.setAttribute('autocomplete', 'off');
  this.screen_.setAttribute('autocorrect', 'off');
  this.screen_.setAttribute('autocapitalize', 'none');

  // In some ways the terminal behaves like a text box but not in all ways. It
  // is not editable in the same ways a text box is editable and the content we
  // want to be read out by a screen reader does not always align with the edits
  // (selection changes) that happen in the terminal window. Use the log role so
  // that the screen reader doesn't treat it like a text box and announce all
  // selection changes. The announcements that we want spoken are generated
  // by a separate live region, which gives more control over what will be
  // spoken.
  this.screen_.setAttribute('role', 'log');
  this.screen_.setAttribute('aria-live', 'off');
  this.screen_.setAttribute('aria-roledescription', 'Terminal');

  // Set aria-readonly to indicate to the screen reader that the text on the
  // screen is not modifiable by the html cursor. It may be modifiable by
  // sending input to the application running in the terminal, but this is
  // orthogonal to the DOM's notion of modifiable.
  this.screen_.setAttribute('aria-readonly', 'true');
  this.screen_.setAttribute('tabindex', '-1');
  this.screen_.style.cssText = (
      'caret-color: transparent;' +
      'display: block;' +
      'font-family: monospace;' +
      'font-size: 15px;' +
      'font-variant-ligatures: none;' +
      'height: 100%;' +
      'overflow-y: scroll; overflow-x: hidden;' +
      'white-space: pre;' +
      'width: 100%;' +
      'outline: none !important');

  doc.body.appendChild(this.screen_);

  this.screen_.addEventListener('scroll', this.onScroll_.bind(this));
  this.screen_.addEventListener('wheel', this.onScrollWheel_.bind(this));
  this.screen_.addEventListener('touchstart', this.onTouch_.bind(this));
  this.screen_.addEventListener('touchmove', this.onTouch_.bind(this));
  this.screen_.addEventListener('touchend', this.onTouch_.bind(this));
  this.screen_.addEventListener('touchcancel', this.onTouch_.bind(this));
  this.screen_.addEventListener('copy', this.onCopy_.bind(this));
  this.screen_.addEventListener('paste', this.onPaste_.bind(this));
  this.screen_.addEventListener('drop', this.onDragAndDrop_.bind(this));

  doc.body.addEventListener('keydown', this.onBodyKeyDown_.bind(this));

  // Add buttons to make accessible scrolling through terminal history work
  // well. These are positioned off-screen until they are selected, at which
  // point they are moved on-screen.
  const scrollButtonHeight = 30;
  const scrollButtonBorder = 1;
  const scrollButtonTotalHeight = scrollButtonHeight + 2 * scrollButtonBorder;
  const scrollButtonStyle = `right: 0px;
                             position:fixed;
                             z-index: 1;
                             text-align: center;
                             cursor: pointer;
                             height: ${scrollButtonHeight}px;
                             width: 110px;
                             line-height: ${scrollButtonHeight}px;
                             border-width: ${scrollButtonBorder}px;
                             border-style: solid;
                             font-weight: bold;`;
  // Note: we use a <div> rather than a <button> because we don't want it to be
  // focusable. If it's focusable this interferes with the contenteditable
  // focus.
  this.scrollUpButton_ = this.document_.createElement('div');
  this.scrollUpButton_.id = 'hterm:a11y:page-up';
  this.scrollUpButton_.innerText = hterm.msg('BUTTON_PAGE_UP', [], 'Page up');
  this.scrollUpButton_.setAttribute('role', 'button');
  this.scrollUpButton_.style.cssText = scrollButtonStyle;
  this.scrollUpButton_.style.top = -scrollButtonTotalHeight + 'px';
  this.scrollUpButton_.addEventListener('click', this.scrollPageUp.bind(this));

  this.scrollDownButton_ = this.document_.createElement('div');
  this.scrollDownButton_.id = 'hterm:a11y:page-down';
  this.scrollDownButton_.innerText =
      hterm.msg('BUTTON_PAGE_DOWN', [], 'Page down');
  this.scrollDownButton_.setAttribute('role', 'button');
  this.scrollDownButton_.style.cssText = scrollButtonStyle;
  this.scrollDownButton_.style.bottom = -scrollButtonTotalHeight + 'px';
  this.scrollDownButton_.addEventListener(
      'click', this.scrollPageDown.bind(this));

  // We only allow the scroll buttons to display after a delay, otherwise the
  // page up button can flash onto the screen during the intial change in focus.
  // This seems to be because it is the first element inside the <x-screen>
  // element, which will get focussed on page load.
  this.allowScrollButtonsToDisplay_ = false;
  setTimeout(() => { this.allowScrollButtonsToDisplay_ = true; }, 500);
  this.document_.addEventListener('selectionchange', () => {
    this.selection.sync();

    if (!this.allowScrollButtonsToDisplay_)
      return;

    const accessibilityEnabled = this.accessibilityReader_ &&
        this.accessibilityReader_.accessibilityEnabled;

    const selection = this.document_.getSelection();
    let selectedElement;
    if (selection.anchorNode && selection.anchorNode.parentElement) {
      selectedElement = selection.anchorNode.parentElement;
    }
    if (accessibilityEnabled && selectedElement == this.scrollUpButton_) {
      this.scrollUpButton_.style.top = '0px';
    } else {
      this.scrollUpButton_.style.top = -scrollButtonTotalHeight + 'px';
    }
    if (accessibilityEnabled && selectedElement == this.scrollDownButton_) {
      this.scrollDownButton_.style.bottom = '0px';
    } else {
      this.scrollDownButton_.style.bottom = -scrollButtonTotalHeight + 'px';
    }
  });

  this.screen_.appendChild(this.scrollUpButton_);

  // This is the main container for the fixed rows.
  this.rowNodes_ = doc.createElement('div');
  this.rowNodes_.id = 'hterm:row-nodes';
  this.rowNodes_.style.cssText = (
      'display: block;' +
      'position: fixed;' +
      'overflow: hidden;' +
      '-webkit-user-select: text;' +
      '-moz-user-select: text;');
  this.screen_.appendChild(this.rowNodes_);

  this.screen_.appendChild(this.scrollDownButton_);

  // Two nodes to hold offscreen text during the copy event.
  this.topSelectBag_ = doc.createElement('x-select-bag');
  this.topSelectBag_.style.cssText = (
      'display: block;' +
      'overflow: hidden;' +
      'height: var(--hterm-charsize-height);' +
      'white-space: pre;');

  this.bottomSelectBag_ = this.topSelectBag_.cloneNode();

  // Nodes above the top fold and below the bottom fold are hidden.  They are
  // only used to hold rows that are part of the selection but are currently
  // scrolled off the top or bottom of the visible range.
  this.topFold_ = doc.createElement('x-fold');
  this.topFold_.id = 'hterm:top-fold-for-row-selection';
  this.topFold_.style.cssText = 'display: block;';
  this.rowNodes_.appendChild(this.topFold_);

  this.bottomFold_ = this.topFold_.cloneNode();
  this.bottomFold_.id = 'hterm:bottom-fold-for-row-selection';
  this.rowNodes_.appendChild(this.bottomFold_);

  // This hidden div accounts for the vertical space that would be consumed by
  // all the rows in the buffer if they were visible.  It's what causes the
  // scrollbar to appear on the 'x-screen', and it moves within the screen when
  // the scrollbar is moved.
  //
  // It is set 'visibility: hidden' to keep the browser from trying to include
  // it in the selection when a user 'drag selects' upwards (drag the mouse to
  // select and scroll at the same time).  Without this, the selection gets
  // out of whack.
  this.scrollArea_ = doc.createElement('div');
  this.scrollArea_.id = 'hterm:scrollarea';
  this.scrollArea_.style.cssText = 'visibility: hidden';
  this.screen_.appendChild(this.scrollArea_);

  // This svg element is used to detect when the browser is zoomed.  It must be
  // placed in the outermost document for currentScale to be correct.
  // TODO(rginda): This means that hterm nested in an iframe will not correctly
  // detect browser zoom level.  We should come up with a better solution.
  // Note: This must be http:// else Chrome cannot create the element correctly.
  var xmlns = 'http://www.w3.org/2000/svg';
  this.svg_ = this.div_.ownerDocument.createElementNS(xmlns, 'svg');
  this.svg_.id = 'hterm:zoom-detector';
  this.svg_.setAttribute('xmlns', xmlns);
  this.svg_.setAttribute('version', '1.1');
  this.svg_.style.cssText = (
      'position: absolute;' +
      'top: 0;' +
      'left: 0;' +
      'visibility: hidden');


  // We send focus to this element just before a paste happens, so we can
  // capture the pasted text and forward it on to someone who cares.
  this.pasteTarget_ = doc.createElement('textarea');
  this.pasteTarget_.id = 'hterm:ctrl-v-paste-target';
  this.pasteTarget_.setAttribute('tabindex', '-1');
  this.pasteTarget_.setAttribute('aria-hidden', 'true');
  this.pasteTarget_.style.cssText = (
    'position: absolute;' +
    'height: 1px;' +
    'width: 1px;' +
    'left: 0px; ' +
    'bottom: 0px;' +
    'opacity: 0');
  this.pasteTarget_.contentEditable = true;

  this.screen_.appendChild(this.pasteTarget_);
  this.pasteTarget_.addEventListener(
      'textInput', this.handlePasteTargetTextInput_.bind(this));

  this.resize();
};

/**
 * Set the AccessibilityReader object to use to announce page scroll updates.
 *
 * @param {hterm.AccessibilityReader} accessibilityReader for announcing page
 *     scroll updates.
 */
hterm.ScrollPort.prototype.setAccessibilityReader =
    function(accessibilityReader) {
  this.accessibilityReader_ = accessibilityReader;
};

/**
 * Scroll the terminal one page up (minus one line) relative to the current
 * position.
 */
hterm.ScrollPort.prototype.scrollPageUp = function() {
  if (this.getTopRowIndex() == 0) {
    return;
  }

  const i = this.getTopRowIndex();
  this.scrollRowToTop(i - this.visibleRowCount + 1);

  this.assertiveAnnounce_();
};

/**
 * Scroll the terminal one page down (minus one line) relative to the current
 * position.
 */
hterm.ScrollPort.prototype.scrollPageDown = function() {
  if (this.isScrolledEnd) {
    return;
  }

  const i = this.getTopRowIndex();
  this.scrollRowToTop(i + this.visibleRowCount - 1);

  this.assertiveAnnounce_();
};

/**
 * Select the font-family and font-smoothing for this scrollport.
 *
 * @param {string} fontFamily Value of the CSS 'font-family' to use for this
 *     scrollport.  Should be a monospace font.
 * @param {string} opt_smoothing Optional value for '-webkit-font-smoothing'.
 *     Defaults to an empty string if not specified.
 */
hterm.ScrollPort.prototype.setFontFamily = function(fontFamily, opt_smoothing) {
  this.screen_.style.fontFamily = fontFamily;
  if (opt_smoothing) {
    this.screen_.style.webkitFontSmoothing = opt_smoothing;
  } else {
    this.screen_.style.webkitFontSmoothing = '';
  }

  this.syncCharacterSize();
};

hterm.ScrollPort.prototype.getFontFamily = function() {
  return this.screen_.style.fontFamily;
};

/**
 * Set a custom stylesheet to include in the scrollport.
 *
 * Defaults to null, meaning no custom css is loaded.  Set it back to null or
 * the empty string to remove a previously applied custom css.
 */
hterm.ScrollPort.prototype.setUserCssUrl = function(url) {
  if (url) {
    this.userCssLink_.setAttribute('href', url);

    if (!this.userCssLink_.parentNode)
      this.document_.head.appendChild(this.userCssLink_);
  } else if (this.userCssLink_.parentNode) {
    this.document_.head.removeChild(this.userCssLink_);
  }
};

hterm.ScrollPort.prototype.setUserCssText = function(text) {
  this.userCssText_.textContent = text;
};

hterm.ScrollPort.prototype.focus = function() {
  this.iframe_.focus();
  this.screen_.focus();
  this.publish('focus');
};

hterm.ScrollPort.prototype.getForegroundColor = function() {
  return this.screen_.style.color;
};

hterm.ScrollPort.prototype.setForegroundColor = function(color) {
  this.screen_.style.color = color;
  this.scrollUpButton_.style.backgroundColor = color;
  this.scrollDownButton_.style.backgroundColor = color;
};

hterm.ScrollPort.prototype.getBackgroundColor = function() {
  return this.screen_.style.backgroundColor;
};

hterm.ScrollPort.prototype.setBackgroundColor = function(color) {
  this.screen_.style.backgroundColor = color;
  this.scrollUpButton_.style.color = color;
  this.scrollDownButton_.style.color = color;
};

hterm.ScrollPort.prototype.setBackgroundImage = function(image) {
  this.screen_.style.backgroundImage = image;
};

hterm.ScrollPort.prototype.setBackgroundSize = function(size) {
  this.screen_.style.backgroundSize = size;
};

hterm.ScrollPort.prototype.setBackgroundPosition = function(position) {
  this.screen_.style.backgroundPosition = position;
};

hterm.ScrollPort.prototype.setCtrlVPaste = function(ctrlVPaste) {
  this.ctrlVPaste = ctrlVPaste;
};

hterm.ScrollPort.prototype.setPasteOnDrop = function(pasteOnDrop) {
  this.pasteOnDrop = pasteOnDrop;
};

/**
 * Get the usable size of the scrollport screen.
 *
 * The width will not include the scrollbar width.
 */
hterm.ScrollPort.prototype.getScreenSize = function() {
  var size = hterm.getClientSize(this.screen_);
  return {
    height: size.height,
    width: size.width - this.currentScrollbarWidthPx
  };
};

/**
 * Get the usable width of the scrollport screen.
 *
 * This the widget width minus scrollbar width.
 */
hterm.ScrollPort.prototype.getScreenWidth = function() {
  return this.getScreenSize().width ;
};

/**
 * Get the usable height of the scrollport screen.
 */
hterm.ScrollPort.prototype.getScreenHeight = function() {
  return this.getScreenSize().height;
};

/**
 * Return the document that holds the visible rows of this hterm.ScrollPort.
 */
hterm.ScrollPort.prototype.getDocument = function() {
  return this.document_;
};

/**
 * Returns the x-screen element that holds the rows of this hterm.ScrollPort.
 */
hterm.ScrollPort.prototype.getScreenNode = function() {
  return this.screen_;
};

/**
 * Clear out any cached rowNodes.
 */
hterm.ScrollPort.prototype.resetCache = function() {
  this.currentRowNodeCache_ = null;
  this.previousRowNodeCache_ = {};
};

/**
 * Change the current rowProvider.
 *
 * This will clear the row cache and cause a redraw.
 *
 * @param {Object} rowProvider An object capable of providing the rows
 *     in this hterm.ScrollPort.
 */
hterm.ScrollPort.prototype.setRowProvider = function(rowProvider) {
  this.resetCache();
  this.rowProvider_ = rowProvider;
  this.scheduleRedraw();
};

/**
 * Inform the ScrollPort that the root DOM nodes for some or all of the visible
 * rows are no longer valid.
 *
 * Specifically, this should be called if this.rowProvider_.getRowNode() now
 * returns an entirely different node than it did before.  It does not
 * need to be called if the content of a row node is the only thing that
 * changed.
 *
 * This skips some of the overhead of a full redraw, but should not be used
 * in cases where the scrollport has been scrolled, or when the row count has
 * changed.
 */
hterm.ScrollPort.prototype.invalidate = function() {
  var node = this.topFold_.nextSibling;
  while (node != this.bottomFold_) {
    var nextSibling = node.nextSibling;
    node.parentElement.removeChild(node);
    node = nextSibling;
  }

  this.previousRowNodeCache_ = null;
  var topRowIndex = this.getTopRowIndex();
  var bottomRowIndex = this.getBottomRowIndex(topRowIndex);

  this.drawVisibleRows_(topRowIndex, bottomRowIndex);
};

hterm.ScrollPort.prototype.scheduleInvalidate = function() {
  if (this.timeouts_.invalidate)
    return;

  var self = this;
  this.timeouts_.invalidate = setTimeout(function () {
      delete self.timeouts_.invalidate;
      self.invalidate();
    }, 0);
};

/**
 * Set the font size of the ScrollPort.
 */
hterm.ScrollPort.prototype.setFontSize = function(px) {
  this.screen_.style.fontSize = px + 'px';
  this.syncCharacterSize();
};

/**
 * Return the current font size of the ScrollPort.
 */
hterm.ScrollPort.prototype.getFontSize = function() {
  return parseInt(this.screen_.style.fontSize);
};

/**
 * Measure the size of a single character in pixels.
 *
 * @param {string} opt_weight The font weight to measure, or 'normal' if
 *     omitted.
 * @return {hterm.Size} A new hterm.Size object.
 */
hterm.ScrollPort.prototype.measureCharacterSize = function(opt_weight) {
  // Number of lines used to average the height of a single character.
  var numberOfLines = 100;
  // Number of chars per line used to average the width of a single character.
  var lineLength = 100;

  if (!this.ruler_) {
    this.ruler_ = this.document_.createElement('div');
    this.ruler_.id = 'hterm:ruler-character-size';
    this.ruler_.style.cssText = (
        'position: absolute;' +
        'top: 0;' +
        'left: 0;' +
        'visibility: hidden;' +
        'height: auto !important;' +
        'width: auto !important;');

    // We need to put the text in a span to make the size calculation
    // work properly in Firefox
    this.rulerSpan_ = this.document_.createElement('span');
    this.rulerSpan_.id = 'hterm:ruler-span-workaround';
    this.rulerSpan_.innerHTML =
        ('X'.repeat(lineLength) + '\r').repeat(numberOfLines);
    this.ruler_.appendChild(this.rulerSpan_);

    this.rulerBaseline_ = this.document_.createElement('span');
    this.rulerSpan_.id = 'hterm:ruler-baseline';
    // We want to collapse it on the baseline
    this.rulerBaseline_.style.fontSize = '0px';
    this.rulerBaseline_.textContent = 'X';
  }

  this.rulerSpan_.style.fontWeight = opt_weight || '';

  this.rowNodes_.appendChild(this.ruler_);
  var rulerSize = hterm.getClientSize(this.rulerSpan_);

  var size = new hterm.Size(rulerSize.width / lineLength,
                            rulerSize.height / numberOfLines);

  this.ruler_.appendChild(this.rulerBaseline_);
  size.baseline = this.rulerBaseline_.offsetTop;
  this.ruler_.removeChild(this.rulerBaseline_);

  this.rowNodes_.removeChild(this.ruler_);

  this.div_.ownerDocument.body.appendChild(this.svg_);
  size.zoomFactor = this.svg_.currentScale;
  this.div_.ownerDocument.body.removeChild(this.svg_);

  return size;
};

/**
 * Synchronize the character size.
 *
 * This will re-measure the current character size and adjust the height
 * of an x-row to match.
 */
hterm.ScrollPort.prototype.syncCharacterSize = function() {
  this.characterSize = this.measureCharacterSize();

  this.resize();
};

/**
 * Reset dimensions and visible row count to account for a change in the
 * dimensions of the 'x-screen'.
 */
hterm.ScrollPort.prototype.resize = function() {
  this.currentScrollbarWidthPx = hterm.getClientWidth(this.screen_) -
    this.screen_.clientWidth;

  this.syncScrollHeight();
  this.syncRowNodesDimensions_();

  var self = this;
  this.publish(
      'resize', { scrollPort: this },
      function() {
        self.scrollRowToBottom(self.rowProvider_.getRowCount());
        self.scheduleRedraw();
      });
};

/**
 * Announce text content on the current screen for the screen reader.
 */
hterm.ScrollPort.prototype.assertiveAnnounce_ = function() {
  if (!this.accessibilityReader_) {
    return;
  }

  const topRow = this.getTopRowIndex();
  const bottomRow = this.getBottomRowIndex(topRow);

  let percentScrolled = 100 * topRow /
      Math.max(1, this.rowProvider_.getRowCount() - this.visibleRowCount);
  percentScrolled = Math.min(100, Math.round(percentScrolled));
  let currentScreenContent = hterm.msg('ANNOUNCE_CURRENT_SCREEN_HEADER',
                                       [percentScrolled],
                                       '$1% scrolled,');
  currentScreenContent += '\n';

  for (let i = topRow; i <= bottomRow; ++i) {
    const node = this.fetchRowNode_(i);
    currentScreenContent += node.textContent + '\n';
  }

  this.accessibilityReader_.assertiveAnnounce(currentScreenContent);
};

/**
 * Set the position and size of the row nodes element.
 */
hterm.ScrollPort.prototype.syncRowNodesDimensions_ = function() {
  var screenSize = this.getScreenSize();

  this.lastScreenWidth_ = screenSize.width;
  this.lastScreenHeight_ = screenSize.height;

  // We don't want to show a partial row because it would be distracting
  // in a terminal, so we floor any fractional row count.
  this.visibleRowCount = lib.f.smartFloorDivide(
      screenSize.height, this.characterSize.height);

  // Then compute the height of our integral number of rows.
  var visibleRowsHeight = this.visibleRowCount * this.characterSize.height;

  // Then the difference between the screen height and total row height needs to
  // be made up for as top margin.  We need to record this value so it
  // can be used later to determine the topRowIndex.
  this.visibleRowTopMargin = 0;
  this.visibleRowBottomMargin = screenSize.height - visibleRowsHeight;

  this.topFold_.style.marginBottom = this.visibleRowTopMargin + 'px';


  var topFoldOffset = 0;
  var node = this.topFold_.previousSibling;
  while (node) {
    topFoldOffset += hterm.getClientHeight(node);
    node = node.previousSibling;
  }

  // Set the dimensions of the visible rows container.
  this.rowNodes_.style.width = screenSize.width + 'px';
  this.rowNodes_.style.height = visibleRowsHeight + topFoldOffset + 'px';
  this.rowNodes_.style.left = this.screen_.offsetLeft + 'px';
  this.rowNodes_.style.top = this.screen_.offsetTop - topFoldOffset + 'px';
};

hterm.ScrollPort.prototype.syncScrollHeight = function() {
  // Resize the scroll area to appear as though it contains every row.
  this.lastRowCount_ = this.rowProvider_.getRowCount();
  this.scrollArea_.style.height = (this.characterSize.height *
                                   this.lastRowCount_ +
                                   this.visibleRowTopMargin +
                                   this.visibleRowBottomMargin +
                                   'px');
};

/**
 * Schedule a redraw to happen asynchronously.
 *
 * If this method is called multiple times before the redraw has a chance to
 * run only one redraw occurs.
 */
hterm.ScrollPort.prototype.scheduleRedraw = function() {
  if (this.timeouts_.redraw)
    return;

  var self = this;
  this.timeouts_.redraw = setTimeout(function () {
      delete self.timeouts_.redraw;
      self.redraw_();
    }, 0);
};

/**
 * Update the state of scroll up/down buttons.
 *
 * If the viewport is at the top or bottom row of output, these buttons will
 * be made transparent and clicking them shouldn't scroll any further.
 */
hterm.ScrollPort.prototype.updateScrollButtonState_ = function() {
  const setButton = (button, disabled) => {
    button.setAttribute('aria-disabled', disabled ? 'true' : 'false');
    button.style.opacity = disabled ? 0.5 : 1;
  };
  setButton(this.scrollUpButton_, this.getTopRowIndex() == 0);
  setButton(this.scrollDownButton_, this.isScrolledEnd);
};

/**
 * Redraw the current hterm.ScrollPort based on the current scrollbar position.
 *
 * When redrawing, we are careful to make sure that the rows that start or end
 * the current selection are not touched in any way.  Doing so would disturb
 * the selection, and cleaning up after that would cause flashes at best and
 * incorrect selection at worst.  Instead, we modify the DOM around these nodes.
 * We even stash the selection start/end outside of the visible area if
 * they are not supposed to be visible in the hterm.ScrollPort.
 */
hterm.ScrollPort.prototype.redraw_ = function() {
  this.resetSelectBags_();
  this.selection.sync();

  this.syncScrollHeight();

  this.currentRowNodeCache_ = {};

  var topRowIndex = this.getTopRowIndex();
  var bottomRowIndex = this.getBottomRowIndex(topRowIndex);

  this.drawTopFold_(topRowIndex);
  this.drawBottomFold_(bottomRowIndex);
  this.drawVisibleRows_(topRowIndex, bottomRowIndex);

  this.syncRowNodesDimensions_();

  this.previousRowNodeCache_ = this.currentRowNodeCache_;
  this.currentRowNodeCache_ = null;

  this.isScrolledEnd = (
    this.getTopRowIndex() + this.visibleRowCount >= this.lastRowCount_);

  this.updateScrollButtonState_();
};

/**
 * Ensure that the nodes above the top fold are as they should be.
 *
 * If the selection start and/or end nodes are above the visible range
 * of this hterm.ScrollPort then the dom will be adjusted so that they appear
 * before the top fold (the first x-fold element, aka this.topFold).
 *
 * If not, the top fold will be the first element.
 *
 * It is critical that this method does not move the selection nodes.  Doing
 * so would clear the current selection.  Instead, the rest of the DOM is
 * adjusted around them.
 */
hterm.ScrollPort.prototype.drawTopFold_ = function(topRowIndex) {
  if (!this.selection.startRow ||
      this.selection.startRow.rowIndex >= topRowIndex) {
    // Selection is entirely below the top fold, just make sure the fold is
    // the first child.
    if (this.rowNodes_.firstChild != this.topFold_)
      this.rowNodes_.insertBefore(this.topFold_, this.rowNodes_.firstChild);

    return;
  }

  if (!this.selection.isMultiline ||
      this.selection.endRow.rowIndex >= topRowIndex) {
    // Only the startRow is above the fold.
    if (this.selection.startRow.nextSibling != this.topFold_)
      this.rowNodes_.insertBefore(this.topFold_,
                                  this.selection.startRow.nextSibling);
  } else {
    // Both rows are above the fold.
    if (this.selection.endRow.nextSibling != this.topFold_) {
      this.rowNodes_.insertBefore(this.topFold_,
                                  this.selection.endRow.nextSibling);
    }

    // Trim any intermediate lines.
    while (this.selection.startRow.nextSibling !=
           this.selection.endRow) {
      this.rowNodes_.removeChild(this.selection.startRow.nextSibling);
    }
  }

  while(this.rowNodes_.firstChild != this.selection.startRow) {
    this.rowNodes_.removeChild(this.rowNodes_.firstChild);
  }
};

/**
 * Ensure that the nodes below the bottom fold are as they should be.
 *
 * If the selection start and/or end nodes are below the visible range
 * of this hterm.ScrollPort then the dom will be adjusted so that they appear
 * after the bottom fold (the second x-fold element, aka this.bottomFold).
 *
 * If not, the bottom fold will be the last element.
 *
 * It is critical that this method does not move the selection nodes.  Doing
 * so would clear the current selection.  Instead, the rest of the DOM is
 * adjusted around them.
 */
hterm.ScrollPort.prototype.drawBottomFold_ = function(bottomRowIndex) {
  if (!this.selection.endRow ||
      this.selection.endRow.rowIndex <= bottomRowIndex) {
    // Selection is entirely above the bottom fold, just make sure the fold is
    // the last child.
    if (this.rowNodes_.lastChild != this.bottomFold_)
      this.rowNodes_.appendChild(this.bottomFold_);

    return;
  }

  if (!this.selection.isMultiline ||
      this.selection.startRow.rowIndex <= bottomRowIndex) {
    // Only the endRow is below the fold.
    if (this.bottomFold_.nextSibling != this.selection.endRow)
      this.rowNodes_.insertBefore(this.bottomFold_,
                                  this.selection.endRow);
  } else {
    // Both rows are below the fold.
    if (this.bottomFold_.nextSibling != this.selection.startRow) {
      this.rowNodes_.insertBefore(this.bottomFold_,
                                  this.selection.startRow);
    }

    // Trim any intermediate lines.
    while (this.selection.startRow.nextSibling !=
           this.selection.endRow) {
      this.rowNodes_.removeChild(this.selection.startRow.nextSibling);
    }
  }

  while(this.rowNodes_.lastChild != this.selection.endRow) {
    this.rowNodes_.removeChild(this.rowNodes_.lastChild);
  }
};

/**
 * Ensure that the rows between the top and bottom folds are as they should be.
 *
 * This method assumes that drawTopFold_() and drawBottomFold_() have already
 * run, and that they have left any visible selection row (selection start
 * or selection end) between the folds.
 *
 * It recycles DOM nodes from the previous redraw where possible, but will ask
 * the rowSource to make new nodes if necessary.
 *
 * It is critical that this method does not move the selection nodes.  Doing
 * so would clear the current selection.  Instead, the rest of the DOM is
 * adjusted around them.
 */
hterm.ScrollPort.prototype.drawVisibleRows_ = function(
    topRowIndex, bottomRowIndex) {
  var self = this;

  // Keep removing nodes, starting with currentNode, until we encounter
  // targetNode.  Throws on failure.
  function removeUntilNode(currentNode, targetNode) {
    while (currentNode != targetNode) {
      if (!currentNode)
        throw 'Did not encounter target node';

      if (currentNode == self.bottomFold_)
        throw 'Encountered bottom fold before target node';

      var deadNode = currentNode;
      currentNode = currentNode.nextSibling;
      deadNode.parentNode.removeChild(deadNode);
    }
  }

  // Shorthand for things we're going to use a lot.
  var selectionStartRow = this.selection.startRow;
  var selectionEndRow = this.selection.endRow;
  var bottomFold = this.bottomFold_;

  // The node we're examining during the current iteration.
  var node = this.topFold_.nextSibling;

  var targetDrawCount = Math.min(this.visibleRowCount,
                                 this.rowProvider_.getRowCount());

  for (var drawCount = 0; drawCount < targetDrawCount; drawCount++) {
    var rowIndex = topRowIndex + drawCount;

    if (node == bottomFold) {
      // We've hit the bottom fold, we need to insert a new row.
      var newNode = this.fetchRowNode_(rowIndex);
      if (!newNode) {
        console.log("Couldn't fetch row index: " + rowIndex);
        break;
      }

      this.rowNodes_.insertBefore(newNode, node);
      continue;
    }

    if (node.rowIndex == rowIndex) {
      // This node is in the right place, move along.
      node = node.nextSibling;
      continue;
    }

    if (selectionStartRow && selectionStartRow.rowIndex == rowIndex) {
      // The selection start row is supposed to be here, remove nodes until
      // we find it.
      removeUntilNode(node, selectionStartRow);
      node = selectionStartRow.nextSibling;
      continue;
    }

    if (selectionEndRow && selectionEndRow.rowIndex == rowIndex) {
      // The selection end row is supposed to be here, remove nodes until
      // we find it.
      removeUntilNode(node, selectionEndRow);
      node = selectionEndRow.nextSibling;
      continue;
    }

    if (node == selectionStartRow || node == selectionEndRow) {
      // We encountered the start/end of the selection, but we don't want it
      // yet.  Insert a new row instead.
      var newNode = this.fetchRowNode_(rowIndex);
      if (!newNode) {
        console.log("Couldn't fetch row index: " + rowIndex);
        break;
      }

      this.rowNodes_.insertBefore(newNode, node);
      continue;
    }

    // There is nothing special about this node, but it's in our way.  Replace
    // it with the node that should be here.
    var newNode = this.fetchRowNode_(rowIndex);
    if (!newNode) {
      console.log("Couldn't fetch row index: " + rowIndex);
      break;
    }

    if (node == newNode) {
      node = node.nextSibling;
      continue;
    }

    this.rowNodes_.insertBefore(newNode, node);
    if (!newNode.nextSibling)
      debugger;
    this.rowNodes_.removeChild(node);
    node = newNode.nextSibling;
  }

  if (node != this.bottomFold_)
    removeUntilNode(node, bottomFold);
};

/**
 * Empty out both select bags and remove them from the document.
 *
 * These nodes hold the text between the start and end of the selection
 * when that text is otherwise off screen.  They are filled out in the
 * onCopy_ event.
 */
hterm.ScrollPort.prototype.resetSelectBags_ = function() {
  if (this.topSelectBag_.parentNode) {
    this.topSelectBag_.textContent = '';
    this.topSelectBag_.parentNode.removeChild(this.topSelectBag_);
  }

  if (this.bottomSelectBag_.parentNode) {
    this.bottomSelectBag_.textContent = '';
    this.bottomSelectBag_.parentNode.removeChild(this.bottomSelectBag_);
  }
};

/**
 * Place a row node in the cache of visible nodes.
 *
 * This method may only be used during a redraw_.
 */
hterm.ScrollPort.prototype.cacheRowNode_ = function(rowNode) {
  this.currentRowNodeCache_[rowNode.rowIndex] = rowNode;
};

/**
 * Fetch the row node for the given index.
 *
 * This will return a node from the cache if possible, or will request one
 * from the RowProvider if not.
 *
 * If a redraw_ is in progress the row will be added to the current cache.
 */
hterm.ScrollPort.prototype.fetchRowNode_ = function(rowIndex) {
  var node;

  if (this.previousRowNodeCache_ && rowIndex in this.previousRowNodeCache_) {
    node = this.previousRowNodeCache_[rowIndex];
  } else {
    node = this.rowProvider_.getRowNode(rowIndex);
  }

  if (this.currentRowNodeCache_)
    this.cacheRowNode_(node);

  return node;
};

/**
 * Select all rows in the viewport.
 */
hterm.ScrollPort.prototype.selectAll = function() {
  var firstRow;

  if (this.topFold_.nextSibling.rowIndex != 0) {
    while (this.topFold_.previousSibling) {
      this.rowNodes_.removeChild(this.topFold_.previousSibling);
    }

    firstRow = this.fetchRowNode_(0);
    this.rowNodes_.insertBefore(firstRow, this.topFold_);
    this.syncRowNodesDimensions_();
  } else {
    firstRow = this.topFold_.nextSibling;
  }

  var lastRowIndex = this.rowProvider_.getRowCount() - 1;
  var lastRow;

  if (this.bottomFold_.previousSibling.rowIndex != lastRowIndex) {
    while (this.bottomFold_.nextSibling) {
      this.rowNodes_.removeChild(this.bottomFold_.nextSibling);
    }

    lastRow = this.fetchRowNode_(lastRowIndex);
    this.rowNodes_.appendChild(lastRow);
  } else {
    lastRow = this.bottomFold_.previousSibling.rowIndex;
  }

  var selection = this.document_.getSelection();
  selection.collapse(firstRow, 0);
  selection.extend(lastRow, lastRow.childNodes.length);

  this.selection.sync();
};

/**
 * Return the maximum scroll position in pixels.
 */
hterm.ScrollPort.prototype.getScrollMax_ = function(e) {
  return (hterm.getClientHeight(this.scrollArea_) +
          this.visibleRowTopMargin + this.visibleRowBottomMargin -
          hterm.getClientHeight(this.screen_));
};

/**
 * Scroll the given rowIndex to the top of the hterm.ScrollPort.
 *
 * @param {integer} rowIndex Index of the target row.
 */
hterm.ScrollPort.prototype.scrollRowToTop = function(rowIndex) {
  this.syncScrollHeight();

  this.isScrolledEnd = (
    rowIndex + this.visibleRowCount >= this.lastRowCount_);

  var scrollTop = rowIndex * this.characterSize.height +
      this.visibleRowTopMargin;

  var scrollMax = this.getScrollMax_();
  if (scrollTop > scrollMax)
    scrollTop = scrollMax;

  if (this.screen_.scrollTop == scrollTop)
    return;

  this.screen_.scrollTop = scrollTop;
  this.scheduleRedraw();
};

/**
 * Scroll the given rowIndex to the bottom of the hterm.ScrollPort.
 *
 * @param {integer} rowIndex Index of the target row.
 */
hterm.ScrollPort.prototype.scrollRowToBottom = function(rowIndex) {
  this.syncScrollHeight();

  this.isScrolledEnd = (
    rowIndex + this.visibleRowCount >= this.lastRowCount_);

  var scrollTop = rowIndex * this.characterSize.height +
      this.visibleRowTopMargin + this.visibleRowBottomMargin;
  scrollTop -= this.visibleRowCount * this.characterSize.height;

  if (scrollTop < 0)
    scrollTop = 0;

  if (this.screen_.scrollTop == scrollTop)
    return;

  this.screen_.scrollTop = scrollTop;
};

/**
 * Return the row index of the first visible row.
 *
 * This is based on the scroll position.  If a redraw_ is in progress this
 * returns the row that *should* be at the top.
 */
hterm.ScrollPort.prototype.getTopRowIndex = function() {
  return Math.round(this.screen_.scrollTop / this.characterSize.height);
};

/**
 * Return the row index of the last visible row.
 *
 * This is based on the scroll position.  If a redraw_ is in progress this
 * returns the row that *should* be at the bottom.
 */
hterm.ScrollPort.prototype.getBottomRowIndex = function(topRowIndex) {
  return topRowIndex + this.visibleRowCount - 1;
};

/**
 * Handler for scroll events.
 *
 * The onScroll event fires when scrollArea's scrollTop property changes.  This
 * may be due to the user manually move the scrollbar, or a programmatic change.
 */
hterm.ScrollPort.prototype.onScroll_ = function(e) {
  var screenSize = this.getScreenSize();
  if (screenSize.width != this.lastScreenWidth_ ||
      screenSize.height != this.lastScreenHeight_) {
    // This event may also fire during a resize (but before the resize event!).
    // This happens when the browser moves the scrollbar as part of the resize.
    // In these cases, we want to ignore the scroll event and let onResize
    // handle things.  If we don't, then we end up scrolling to the wrong
    // position after a resize.
    this.resize();
    return;
  }

  this.redraw_();
  this.publish('scroll', { scrollPort: this });
};

/**
 * Clients can override this if they want to hear scrollwheel events.
 *
 * Clients may call event.preventDefault() if they want to keep the scrollport
 * from also handling the events.
 */
hterm.ScrollPort.prototype.onScrollWheel = function(e) {};

/**
 * Handler for scroll-wheel events.
 *
 * The onScrollWheel event fires when the user moves their scrollwheel over this
 * hterm.ScrollPort.  Because the frontmost element in the hterm.ScrollPort is
 * a fixed position DIV, the scroll wheel does nothing by default.  Instead, we
 * have to handle it manually.
 */
hterm.ScrollPort.prototype.onScrollWheel_ = function(e) {
  this.onScrollWheel(e);

  if (e.defaultPrevented)
    return;

  // Figure out how far this event wants us to scroll.
  const delta = this.scrollWheelDelta(e);

  let top = this.screen_.scrollTop - delta.y;
  if (top < 0)
    top = 0;

  var scrollMax = this.getScrollMax_();
  if (top > scrollMax)
    top = scrollMax;

  if (top != this.screen_.scrollTop) {
    // Moving scrollTop causes a scroll event, which triggers the redraw.
    this.screen_.scrollTop = top;

    // Only preventDefault when we've actually scrolled.  If there's nothing
    // to scroll we want to pass the event through so Chrome can detect the
    // overscroll.
    e.preventDefault();
  }
};

/**
 * Calculate how far a wheel event should scroll.
 *
 * This normalizes the browser's concept of a scroll (pixels, lines, etc...)
 * into a standard pixel distance.
 *
 * @param {WheelEvent} e The mouse wheel event to process.
 * @return {Object} The x & y of how far (in pixels) to scroll.
 */
hterm.ScrollPort.prototype.scrollWheelDelta = function(e) {
  const delta = {x: 0, y: 0};

  switch (e.deltaMode) {
    case WheelEvent.DOM_DELTA_PIXEL:
      delta.x = e.deltaX * this.scrollWheelMultiplier_;
      delta.y = e.deltaY * this.scrollWheelMultiplier_;
      break;
    case WheelEvent.DOM_DELTA_LINE:
      delta.x = e.deltaX * this.characterSize.width;
      delta.y = e.deltaY * this.characterSize.height;
      break;
    case WheelEvent.DOM_DELTA_PAGE:
      delta.x = e.deltaX * this.characterSize.width * this.screen_.getWidth();
      delta.y = e.deltaY * this.characterSize.height * this.screen_.getHeight();
      break;
  }

  // The Y sign is inverted from what we would expect: up/down are
  // negative/positive respectively.  The X sign is sane though: left/right
  // are negative/positive respectively.
  delta.y *= -1;

  return delta;
};


/**
 * Clients can override this if they want to hear touch events.
 *
 * Clients may call event.preventDefault() if they want to keep the scrollport
 * from also handling the events.
 */
hterm.ScrollPort.prototype.onTouch = function(e) {};

/**
 * Handler for touch events.
 */
hterm.ScrollPort.prototype.onTouch_ = function(e) {
  this.onTouch(e);

  if (e.defaultPrevented)
    return;

  // Extract the fields from the Touch event that we need.  If we saved the
  // event directly, it has references to other objects (like x-row) that
  // might stick around for a long time.  This way we only have small objects
  // in our lastTouch_ state.
  var scrubTouch = function(t) {
    return {
      id: t.identifier,
      y: t.clientY,
      x: t.clientX,
    };
  };

  var i, touch;
  switch (e.type) {
    case 'touchstart':
      // Save the current set of touches.
      for (i = 0; i < e.changedTouches.length; ++i) {
        touch = scrubTouch(e.changedTouches[i]);
        this.lastTouch_[touch.id] = touch;
      }
      break;

    case 'touchcancel':
    case 'touchend':
      // Throw away existing touches that we're finished with.
      for (i = 0; i < e.changedTouches.length; ++i)
        delete this.lastTouch_[e.changedTouches[i].identifier];
      break;

    case 'touchmove':
      // Walk all of the touches in this one event and merge all of their
      // changes into one delta.  This lets multiple fingers scroll faster.
      var delta = 0;
      for (i = 0; i < e.changedTouches.length; ++i) {
        touch = scrubTouch(e.changedTouches[i]);
        delta += (this.lastTouch_[touch.id].y - touch.y);
        this.lastTouch_[touch.id] = touch;
      }

      // Invert to match the touchscreen scrolling direction of browser windows.
      delta *= -1;

      var top = this.screen_.scrollTop - delta;
      if (top < 0)
        top = 0;

      var scrollMax = this.getScrollMax_();
      if (top > scrollMax)
        top = scrollMax;

      if (top != this.screen_.scrollTop) {
        // Moving scrollTop causes a scroll event, which triggers the redraw.
        this.screen_.scrollTop = top;
      }
      break;
  }

  // To disable gestures or anything else interfering with our scrolling.
  e.preventDefault();
};

/**
 * Handler for resize events.
 *
 * The browser will resize us such that the top row stays at the top, but we
 * prefer to the bottom row to stay at the bottom.
 */
hterm.ScrollPort.prototype.onResize_ = function(e) {
  // Re-measure, since onResize also happens for browser zoom changes.
  this.syncCharacterSize();
};

/**
 * Clients can override this if they want to hear copy events.
 *
 * Clients may call event.preventDefault() if they want to keep the scrollport
 * from also handling the events.
 */
hterm.ScrollPort.prototype.onCopy = function(e) { };

/**
 * Handler for copy-to-clipboard events.
 *
 * If some or all of the selected rows are off screen we may need to fill in
 * the rows between selection start and selection end.  This handler determines
 * if we're missing some of the selected text, and if so populates one or both
 * of the "select bags" with the missing text.
 */
hterm.ScrollPort.prototype.onCopy_ = function(e) {
  this.onCopy(e);

  if (e.defaultPrevented)
    return;

  this.resetSelectBags_();
  this.selection.sync();

  if (this.selection.isCollapsed ||
      this.selection.endRow.rowIndex - this.selection.startRow.rowIndex < 2) {
    return;
  }

  var topRowIndex = this.getTopRowIndex();
  var bottomRowIndex = this.getBottomRowIndex(topRowIndex);

  if (this.selection.startRow.rowIndex < topRowIndex) {
    // Start of selection is above the top fold.
    var endBackfillIndex;

    if (this.selection.endRow.rowIndex < topRowIndex) {
      // Entire selection is above the top fold.
      endBackfillIndex = this.selection.endRow.rowIndex;
    } else {
      // Selection extends below the top fold.
      endBackfillIndex = this.topFold_.nextSibling.rowIndex;
    }

    this.topSelectBag_.textContent = this.rowProvider_.getRowsText(
        this.selection.startRow.rowIndex + 1, endBackfillIndex);
    this.rowNodes_.insertBefore(this.topSelectBag_,
                                this.selection.startRow.nextSibling);
    this.syncRowNodesDimensions_();
  }

  if (this.selection.endRow.rowIndex > bottomRowIndex) {
    // Selection ends below the bottom fold.
    var startBackfillIndex;

    if (this.selection.startRow.rowIndex > bottomRowIndex) {
      // Entire selection is below the bottom fold.
      startBackfillIndex = this.selection.startRow.rowIndex + 1;
    } else {
      // Selection starts above the bottom fold.
      startBackfillIndex = this.bottomFold_.previousSibling.rowIndex + 1;
    }

    this.bottomSelectBag_.textContent = this.rowProvider_.getRowsText(
        startBackfillIndex, this.selection.endRow.rowIndex);
    this.rowNodes_.insertBefore(this.bottomSelectBag_, this.selection.endRow);
  }
};

/**
 * Focuses on the paste target on a ctrl-v keydown event, as in
 * FF a content editable element must be focused before the paste event.
 */
hterm.ScrollPort.prototype.onBodyKeyDown_ = function(e) {
  if (!this.ctrlVPaste)
    return;

  if ((e.ctrlKey || e.metaKey) && e.keyCode == 86 /* 'V' */)
    this.pasteTarget_.focus();
};

/**
 * Handle a paste event on the the ScrollPort's screen element.
 *
 * TODO: Handle ClipboardData.files transfers.  https://crbug.com/433581.
 */
hterm.ScrollPort.prototype.onPaste_ = function(e) {
  this.pasteTarget_.focus();

  var self = this;
  setTimeout(function() {
      self.publish('paste', { text: self.pasteTarget_.value });
      self.pasteTarget_.value = '';
      self.focus();
    }, 0);
};

/**
 * Handles a textInput event on the paste target. Stops this from
 * propagating as we want this to be handled in the onPaste_ method.
 */
hterm.ScrollPort.prototype.handlePasteTargetTextInput_ = function(e) {
  e.stopPropagation();
};

/**
 * Handle a drop event on the the ScrollPort's screen element.
 *
 * By default we try to copy in the structured format (HTML/whatever).
 * The shift key can select plain text though.
 *
 * TODO: Handle DataTransfer.files transfers.  https://crbug.com/433581.
 *
 * @param {DragEvent} e The drag event that fired us.
 */
hterm.ScrollPort.prototype.onDragAndDrop_ = function(e) {
  if (!this.pasteOnDrop)
    return;

  e.preventDefault();

  let data;
  let format;

  // If the shift key active, try to find a "rich" text source (but not plain
  // text).  e.g. text/html is OK.
  if (e.shiftKey) {
    e.dataTransfer.types.forEach((t) => {
      if (!format && t != 'text/plain' && t.startsWith('text/'))
        format = t;
    });

    // If we found a non-plain text source, try it out first.
    if (format)
      data = e.dataTransfer.getData(format);
  }

  // If we haven't loaded anything useful, fall back to plain text.
  if (!data)
    data = e.dataTransfer.getData('text/plain');

  if (data)
    this.publish('paste', {text: data});
};

/**
 * Set the vertical scrollbar mode of the ScrollPort.
 */
hterm.ScrollPort.prototype.setScrollbarVisible = function(state) {
  this.screen_.style.overflowY = state ? 'scroll' : 'hidden';
};

/**
 * Set scroll wheel multiplier. This alters how much the screen scrolls on
 * mouse wheel events.
 */
hterm.ScrollPort.prototype.setScrollWheelMoveMultipler = function(multiplier) {
  this.scrollWheelMultiplier_ = multiplier;
};
// SOURCE FILE: hterm/js/hterm_terminal.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

lib.rtdep('lib.colors', 'lib.PreferenceManager', 'lib.resource', 'lib.wc',
          'lib.f', 'hterm.AccessibilityReader', 'hterm.Keyboard',
          'hterm.Options', 'hterm.PreferenceManager', 'hterm.Screen',
          'hterm.ScrollPort', 'hterm.Size', 'hterm.TextAttributes', 'hterm.VT');

/**
 * Constructor for the Terminal class.
 *
 * A Terminal pulls together the hterm.ScrollPort, hterm.Screen and hterm.VT100
 * classes to provide the complete terminal functionality.
 *
 * There are a number of lower-level Terminal methods that can be called
 * directly to manipulate the cursor, text, scroll region, and other terminal
 * attributes.  However, the primary method is interpret(), which parses VT
 * escape sequences and invokes the appropriate Terminal methods.
 *
 * This class was heavily influenced by Cory Maccarrone's Framebuffer class.
 *
 * TODO(rginda): Eventually we're going to need to support characters which are
 * displayed twice as wide as standard latin characters.  This is to support
 * CJK (and possibly other character sets).
 *
 * @param {string} opt_profileId Optional preference profile name.  If not
 *     provided, defaults to 'default'.
 */
hterm.Terminal = function(opt_profileId) {
  this.profileId_ = null;

  // Two screen instances.
  this.primaryScreen_ = new hterm.Screen();
  this.alternateScreen_ = new hterm.Screen();

  // The "current" screen.
  this.screen_ = this.primaryScreen_;

  // The local notion of the screen size.  ScreenBuffers also have a size which
  // indicates their present size.  During size changes, the two may disagree.
  // Also, the inactive screen's size is not altered until it is made the active
  // screen.
  this.screenSize = new hterm.Size(0, 0);

  // The scroll port we'll be using to display the visible rows.
  this.scrollPort_ = new hterm.ScrollPort(this);
  this.scrollPort_.subscribe('resize', this.onResize_.bind(this));
  this.scrollPort_.subscribe('scroll', this.onScroll_.bind(this));
  this.scrollPort_.subscribe('paste', this.onPaste_.bind(this));
  this.scrollPort_.subscribe('focus', this.onScrollportFocus_.bind(this));
  this.scrollPort_.onCopy = this.onCopy_.bind(this);

  // The div that contains this terminal.
  this.div_ = null;

  // The document that contains the scrollPort.  Defaulted to the global
  // document here so that the terminal is functional even if it hasn't been
  // inserted into a document yet, but re-set in decorate().
  this.document_ = window.document;

  // The rows that have scrolled off screen and are no longer addressable.
  this.scrollbackRows_ = [];

  // Saved tab stops.
  this.tabStops_ = [];

  // Keep track of whether default tab stops have been erased; after a TBC
  // clears all tab stops, defaults aren't restored on resize until a reset.
  this.defaultTabStops = true;

  // The VT's notion of the top and bottom rows.  Used during some VT
  // cursor positioning and scrolling commands.
  this.vtScrollTop_ = null;
  this.vtScrollBottom_ = null;

  // The DIV element for the visible cursor.
  this.cursorNode_ = null;

  // The current cursor shape of the terminal.
  this.cursorShape_ = hterm.Terminal.cursorShape.BLOCK;

  // Cursor blink on/off cycle in ms, overwritten by prefs once they're loaded.
  this.cursorBlinkCycle_ = [100, 100];

  // Pre-bound onCursorBlink_ handler, so we don't have to do this for each
  // cursor on/off servicing.
  this.myOnCursorBlink_ = this.onCursorBlink_.bind(this);

  // These prefs are cached so we don't have to read from local storage with
  // each output and keystroke.  They are initialized by the preference manager.
  this.backgroundColor_ = null;
  this.foregroundColor_ = null;
  this.scrollOnOutput_ = null;
  this.scrollOnKeystroke_ = null;
  this.scrollWheelArrowKeys_ = null;

  // True if we should override mouse event reporting to allow local selection.
  this.defeatMouseReports_ = false;

  // Whether to auto hide the mouse cursor when typing.
  this.setAutomaticMouseHiding();
  // Timer to keep mouse visible while it's being used.
  this.mouseHideDelay_ = null;

  // Terminal bell sound.
  this.bellAudio_ = this.document_.createElement('audio');
  this.bellAudio_.id = 'hterm:bell-audio';
  this.bellAudio_.setAttribute('preload', 'auto');

  // The AccessibilityReader object for announcing command output.
  this.accessibilityReader_ = null;

  // The context menu object.
  this.contextMenu = new hterm.ContextMenu();

  // All terminal bell notifications that have been generated (not necessarily
  // shown).
  this.bellNotificationList_ = [];

  // Whether we have permission to display notifications.
  this.desktopNotificationBell_ = false;

  // Cursor position and attributes saved with DECSC.
  this.savedOptions_ = {};

  // The current mode bits for the terminal.
  this.options_ = new hterm.Options();

  // Timeouts we might need to clear.
  this.timeouts_ = {};

  // The VT escape sequence interpreter.
  this.vt = new hterm.VT(this);

  this.saveCursorAndState(true);

  // The keyboard handler.
  this.keyboard = new hterm.Keyboard(this);

  // General IO interface that can be given to third parties without exposing
  // the entire terminal object.
  this.io = new hterm.Terminal.IO(this);

  // True if mouse-click-drag should scroll the terminal.
  this.enableMouseDragScroll = true;

  this.copyOnSelect = null;
  this.mouseRightClickPaste = null;
  this.mousePasteButton = null;

  // Whether to use the default window copy behavior.
  this.useDefaultWindowCopy = false;

  this.clearSelectionAfterCopy = true;

  this.realizeSize_(80, 24);
  this.setDefaultTabStops();

  // Whether we allow images to be shown.
  this.allowImagesInline = null;

  this.reportFocus = false;

  this.setProfile(opt_profileId || 'default',
                  function() { this.onTerminalReady(); }.bind(this));
};

/**
 * Possible cursor shapes.
 */
hterm.Terminal.cursorShape = {
  BLOCK: 'BLOCK',
  BEAM: 'BEAM',
  UNDERLINE: 'UNDERLINE'
};

/**
 * Clients should override this to be notified when the terminal is ready
 * for use.
 *
 * The terminal initialization is asynchronous, and shouldn't be used before
 * this method is called.
 */
hterm.Terminal.prototype.onTerminalReady = function() { };

/**
 * Default tab with of 8 to match xterm.
 */
hterm.Terminal.prototype.tabWidth = 8;

/**
 * Select a preference profile.
 *
 * This will load the terminal preferences for the given profile name and
 * associate subsequent preference changes with the new preference profile.
 *
 * @param {string} profileId The name of the preference profile.  Forward slash
 *     characters will be removed from the name.
 * @param {function} opt_callback Optional callback to invoke when the profile
 *     transition is complete.
 */
hterm.Terminal.prototype.setProfile = function(profileId, opt_callback) {
  this.profileId_ = profileId.replace(/\//g, '');

  var terminal = this;

  if (this.prefs_)
    this.prefs_.deactivate();

  this.prefs_ = new hterm.PreferenceManager(this.profileId_);
  this.prefs_.addObservers(null, {
    'alt-gr-mode': function(v) {
      if (v == null) {
        if (navigator.language.toLowerCase() == 'en-us') {
          v = 'none';
        } else {
          v = 'right-alt';
        }
      } else if (typeof v == 'string') {
        v = v.toLowerCase();
      } else {
        v = 'none';
      }

      if (!/^(none|ctrl-alt|left-alt|right-alt)$/.test(v))
        v = 'none';

      terminal.keyboard.altGrMode = v;
    },

    'alt-backspace-is-meta-backspace': function(v) {
      terminal.keyboard.altBackspaceIsMetaBackspace = v;
    },

    'alt-is-meta': function(v) {
      terminal.keyboard.altIsMeta = v;
    },

    'alt-sends-what': function(v) {
      if (!/^(escape|8-bit|browser-key)$/.test(v))
        v = 'escape';

      terminal.keyboard.altSendsWhat = v;
    },

    'audible-bell-sound': function(v) {
      var ary = v.match(/^lib-resource:(\S+)/);
      if (ary) {
        terminal.bellAudio_.setAttribute('src',
                                         lib.resource.getDataUrl(ary[1]));
      } else {
        terminal.bellAudio_.setAttribute('src', v);
      }
    },

    'desktop-notification-bell': function(v) {
      if (v && Notification) {
        terminal.desktopNotificationBell_ =
            Notification.permission === 'granted';
        if (!terminal.desktopNotificationBell_) {
          // Note: We don't call Notification.requestPermission here because
          // Chrome requires the call be the result of a user action (such as an
          // onclick handler), and pref listeners are run asynchronously.
          //
          // A way of working around this would be to display a dialog in the
          // terminal with a "click-to-request-permission" button.
          console.warn('desktop-notification-bell is true but we do not have ' +
                       'permission to display notifications.');
        }
      } else {
        terminal.desktopNotificationBell_ = false;
      }
    },

    'background-color': function(v) {
      terminal.setBackgroundColor(v);
    },

    'background-image': function(v) {
      terminal.scrollPort_.setBackgroundImage(v);
    },

    'background-size': function(v) {
      terminal.scrollPort_.setBackgroundSize(v);
    },

    'background-position': function(v) {
      terminal.scrollPort_.setBackgroundPosition(v);
    },

    'backspace-sends-backspace': function(v) {
      terminal.keyboard.backspaceSendsBackspace = v;
    },

    'character-map-overrides': function(v) {
      if (!(v == null || v instanceof Object)) {
        console.warn('Preference character-map-modifications is not an ' +
                     'object: ' + v);
        return;
      }

      terminal.vt.characterMaps.reset();
      terminal.vt.characterMaps.setOverrides(v);
    },

    'cursor-blink': function(v) {
      terminal.setCursorBlink(!!v);
    },

    'cursor-blink-cycle': function(v) {
        if (v instanceof Array &&
            typeof v[0] == 'number' &&
            typeof v[1] == 'number') {
          terminal.cursorBlinkCycle_ = v;
        } else if (typeof v == 'number') {
          terminal.cursorBlinkCycle_ = [v, v];
        } else {
          // Fast blink indicates an error.
          terminal.cursorBlinkCycle_ = [100, 100];
        }
    },

    'cursor-color': function(v) {
      terminal.setCursorColor(v);
    },

    'color-palette-overrides': function(v) {
      if (!(v == null || v instanceof Object || v instanceof Array)) {
        console.warn('Preference color-palette-overrides is not an array or ' +
                     'object: ' + v);
        return;
      }

      lib.colors.colorPalette = lib.colors.stockColorPalette.concat();

      if (v) {
        for (var key in v) {
          var i = parseInt(key);
          if (isNaN(i) || i < 0 || i > 255) {
            console.log('Invalid value in palette: ' + key + ': ' + v[key]);
            continue;
          }

          if (v[i]) {
            var rgb = lib.colors.normalizeCSS(v[i]);
            if (rgb)
              lib.colors.colorPalette[i] = rgb;
          }
        }
      }

      terminal.primaryScreen_.textAttributes.resetColorPalette();
      terminal.alternateScreen_.textAttributes.resetColorPalette();
    },

    'copy-on-select': function(v) {
      terminal.copyOnSelect = !!v;
    },

    'use-default-window-copy': function(v) {
      terminal.useDefaultWindowCopy = !!v;
    },

    'clear-selection-after-copy': function(v) {
      terminal.clearSelectionAfterCopy = !!v;
    },

    'ctrl-plus-minus-zero-zoom': function(v) {
      terminal.keyboard.ctrlPlusMinusZeroZoom = v;
    },

    'ctrl-c-copy': function(v) {
      terminal.keyboard.ctrlCCopy = v;
    },

    'ctrl-v-paste': function(v) {
      terminal.keyboard.ctrlVPaste = v;
      terminal.scrollPort_.setCtrlVPaste(v);
    },

    'paste-on-drop': function(v) {
      terminal.scrollPort_.setPasteOnDrop(v);
    },

    'east-asian-ambiguous-as-two-column': function(v) {
      lib.wc.regardCjkAmbiguous = v;
    },

    'enable-8-bit-control': function(v) {
      terminal.vt.enable8BitControl = !!v;
    },

    'enable-bold': function(v) {
      terminal.syncBoldSafeState();
    },

    'enable-bold-as-bright': function(v) {
      terminal.primaryScreen_.textAttributes.enableBoldAsBright = !!v;
      terminal.alternateScreen_.textAttributes.enableBoldAsBright = !!v;
    },

    'enable-blink': function(v) {
      terminal.setTextBlink(!!v);
    },

    'enable-clipboard-write': function(v) {
      terminal.vt.enableClipboardWrite = !!v;
    },

    'enable-dec12': function(v) {
      terminal.vt.enableDec12 = !!v;
    },

    'enable-csi-j-3': function(v) {
      terminal.vt.enableCsiJ3 = !!v;
    },

    'font-family': function(v) {
      terminal.syncFontFamily();
    },

    'font-size': function(v) {
      v = parseInt(v);
      if (v <= 0) {
        console.error(`Invalid font size: ${v}`);
        return;
      }

      terminal.setFontSize(v);
    },

    'font-smoothing': function(v) {
      terminal.syncFontFamily();
    },

    'foreground-color': function(v) {
      terminal.setForegroundColor(v);
    },

    'hide-mouse-while-typing': function(v) {
      terminal.setAutomaticMouseHiding(v);
    },

    'home-keys-scroll': function(v) {
      terminal.keyboard.homeKeysScroll = v;
    },

    'keybindings': function(v) {
      terminal.keyboard.bindings.clear();

      if (!v)
        return;

      if (!(v instanceof Object)) {
        console.error('Error in keybindings preference: Expected object');
        return;
      }

      try {
        terminal.keyboard.bindings.addBindings(v);
      } catch (ex) {
        console.error('Error in keybindings preference: ' + ex);
      }
    },

    'media-keys-are-fkeys': function(v) {
      terminal.keyboard.mediaKeysAreFKeys = v;
    },

    'meta-sends-escape': function(v) {
      terminal.keyboard.metaSendsEscape = v;
    },

    'mouse-right-click-paste': function(v) {
      terminal.mouseRightClickPaste = v;
    },

    'mouse-paste-button': function(v) {
      terminal.syncMousePasteButton();
    },

    'page-keys-scroll': function(v) {
      terminal.keyboard.pageKeysScroll = v;
    },

    'pass-alt-number': function(v) {
      if (v == null) {
        // Let Alt-1..9 pass to the browser (to control tab switching) on
        // non-OS X systems, or if hterm is not opened in an app window.
        v = (hterm.os != 'mac' && hterm.windowType != 'popup');
      }

      terminal.passAltNumber = v;
    },

    'pass-ctrl-number': function(v) {
      if (v == null) {
        // Let Ctrl-1..9 pass to the browser (to control tab switching) on
        // non-OS X systems, or if hterm is not opened in an app window.
        v = (hterm.os != 'mac' && hterm.windowType != 'popup');
      }

      terminal.passCtrlNumber = v;
    },

    'pass-meta-number': function(v) {
      if (v == null) {
        // Let Meta-1..9 pass to the browser (to control tab switching) on
        // OS X systems, or if hterm is not opened in an app window.
        v = (hterm.os == 'mac' && hterm.windowType != 'popup');
      }

      terminal.passMetaNumber = v;
    },

    'pass-meta-v': function(v) {
      terminal.keyboard.passMetaV = v;
    },

    'receive-encoding': function(v) {
       if (!(/^(utf-8|raw)$/).test(v)) {
         console.warn('Invalid value for "receive-encoding": ' + v);
         v = 'utf-8';
       }

       terminal.vt.characterEncoding = v;
    },

    'scroll-on-keystroke': function(v) {
      terminal.scrollOnKeystroke_ = v;
    },

    'scroll-on-output': function(v) {
      terminal.scrollOnOutput_ = v;
    },

    'scrollbar-visible': function(v) {
      terminal.setScrollbarVisible(v);
    },

    'scroll-wheel-may-send-arrow-keys': function(v) {
      terminal.scrollWheelArrowKeys_ = v;
    },

    'scroll-wheel-move-multiplier': function(v) {
      terminal.setScrollWheelMoveMultipler(v);
    },

    'shift-insert-paste': function(v) {
      terminal.keyboard.shiftInsertPaste = v;
    },

    'terminal-encoding': function(v) {
      terminal.vt.setEncoding(v);
    },

    'user-css': function(v) {
      terminal.scrollPort_.setUserCssUrl(v);
    },

    'user-css-text': function(v) {
      terminal.scrollPort_.setUserCssText(v);
    },

    'word-break-match-left': function(v) {
      terminal.primaryScreen_.wordBreakMatchLeft = v;
      terminal.alternateScreen_.wordBreakMatchLeft = v;
    },

    'word-break-match-right': function(v) {
      terminal.primaryScreen_.wordBreakMatchRight = v;
      terminal.alternateScreen_.wordBreakMatchRight = v;
    },

    'word-break-match-middle': function(v) {
      terminal.primaryScreen_.wordBreakMatchMiddle = v;
      terminal.alternateScreen_.wordBreakMatchMiddle = v;
    },

    'allow-images-inline': function(v) {
      terminal.allowImagesInline = v;
    },
  });

  this.prefs_.readStorage(function() {
    this.prefs_.notifyAll();

    if (opt_callback)
      opt_callback();
  }.bind(this));
};


/**
 * Returns the preferences manager used for configuring this terminal.
 *
 * @return {hterm.PreferenceManager}
 */
hterm.Terminal.prototype.getPrefs = function() {
  return this.prefs_;
};

/**
 * Enable or disable bracketed paste mode.
 *
 * @param {boolean} state The value to set.
 */
hterm.Terminal.prototype.setBracketedPaste = function(state) {
  this.options_.bracketedPaste = state;
};

/**
 * Set the color for the cursor.
 *
 * If you want this setting to persist, set it through prefs_, rather than
 * with this method.
 *
 * @param {string=} color The color to set.  If not defined, we reset to the
 *     saved user preference.
 */
hterm.Terminal.prototype.setCursorColor = function(color) {
  if (color === undefined)
    color = this.prefs_.get('cursor-color');

  this.setCssVar('cursor-color', color);
};

/**
 * Return the current cursor color as a string.
 * @return {string}
 */
hterm.Terminal.prototype.getCursorColor = function() {
  return this.getCssVar('cursor-color');
};

/**
 * Enable or disable mouse based text selection in the terminal.
 *
 * @param {boolean} state The value to set.
 */
hterm.Terminal.prototype.setSelectionEnabled = function(state) {
  this.enableMouseDragScroll = state;
};

/**
 * Set the background color.
 *
 * If you want this setting to persist, set it through prefs_, rather than
 * with this method.
 *
 * @param {string=} color The color to set.  If not defined, we reset to the
 *     saved user preference.
 */
hterm.Terminal.prototype.setBackgroundColor = function(color) {
  if (color === undefined)
    color = this.prefs_.get('background-color');

  this.backgroundColor_ = lib.colors.normalizeCSS(color);
  this.primaryScreen_.textAttributes.setDefaults(
      this.foregroundColor_, this.backgroundColor_);
  this.alternateScreen_.textAttributes.setDefaults(
      this.foregroundColor_, this.backgroundColor_);
  this.scrollPort_.setBackgroundColor(color);
};

/**
 * Return the current terminal background color.
 *
 * Intended for use by other classes, so we don't have to expose the entire
 * prefs_ object.
 *
 * @return {string}
 */
hterm.Terminal.prototype.getBackgroundColor = function() {
  return this.backgroundColor_;
};

/**
 * Set the foreground color.
 *
 * If you want this setting to persist, set it through prefs_, rather than
 * with this method.
 *
 * @param {string=} color The color to set.  If not defined, we reset to the
 *     saved user preference.
 */
hterm.Terminal.prototype.setForegroundColor = function(color) {
  if (color === undefined)
    color = this.prefs_.get('foreground-color');

  this.foregroundColor_ = lib.colors.normalizeCSS(color);
  this.primaryScreen_.textAttributes.setDefaults(
      this.foregroundColor_, this.backgroundColor_);
  this.alternateScreen_.textAttributes.setDefaults(
      this.foregroundColor_, this.backgroundColor_);
  this.scrollPort_.setForegroundColor(color);
};

/**
 * Return the current terminal foreground color.
 *
 * Intended for use by other classes, so we don't have to expose the entire
 * prefs_ object.
 *
 * @return {string}
 */
hterm.Terminal.prototype.getForegroundColor = function() {
  return this.foregroundColor_;
};

/**
 * Create a new instance of a terminal command and run it with a given
 * argument string.
 *
 * @param {function} commandClass The constructor for a terminal command.
 * @param {string} argString The argument string to pass to the command.
 */
hterm.Terminal.prototype.runCommandClass = function(commandClass, argString) {
  var environment = this.prefs_.get('environment');
  if (typeof environment != 'object' || environment == null)
    environment = {};

  var self = this;
  this.command = new commandClass(
      { argString: argString || '',
        io: this.io.push(),
        environment: environment,
        onExit: function(code) {
          self.io.pop();
          self.uninstallKeyboard();
          if (self.prefs_.get('close-on-exit'))
              window.close();
        }
      });

  this.installKeyboard();
  this.command.run();
};

/**
 * Returns true if the current screen is the primary screen, false otherwise.
 *
 * @return {boolean}
 */
hterm.Terminal.prototype.isPrimaryScreen = function() {
  return this.screen_ == this.primaryScreen_;
};

/**
 * Install the keyboard handler for this terminal.
 *
 * This will prevent the browser from seeing any keystrokes sent to the
 * terminal.
 */
hterm.Terminal.prototype.installKeyboard = function() {
  this.keyboard.installKeyboard(this.scrollPort_.getDocument().body);
};

/**
 * Uninstall the keyboard handler for this terminal.
 */
hterm.Terminal.prototype.uninstallKeyboard = function() {
  this.keyboard.installKeyboard(null);
};

/**
 * Set a CSS variable.
 *
 * Normally this is used to set variables in the hterm namespace.
 *
 * @param {string} name The variable to set.
 * @param {string} value The value to assign to the variable.
 * @param {string?} opt_prefix The variable namespace/prefix to use.
 */
hterm.Terminal.prototype.setCssVar = function(name, value,
                                              opt_prefix='--hterm-') {
  this.document_.documentElement.style.setProperty(
      `${opt_prefix}${name}`, value);
};

/**
 * Get a CSS variable.
 *
 * Normally this is used to get variables in the hterm namespace.
 *
 * @param {string} name The variable to read.
 * @param {string?} opt_prefix The variable namespace/prefix to use.
 * @return {string} The current setting for this variable.
 */
hterm.Terminal.prototype.getCssVar = function(name, opt_prefix='--hterm-') {
  return this.document_.documentElement.style.getPropertyValue(
      `${opt_prefix}${name}`);
};

/**
 * Set the font size for this terminal.
 *
 * Call setFontSize(0) to reset to the default font size.
 *
 * This function does not modify the font-size preference.
 *
 * @param {number} px The desired font size, in pixels.
 */
hterm.Terminal.prototype.setFontSize = function(px) {
  if (px <= 0)
    px = this.prefs_.get('font-size');

  this.scrollPort_.setFontSize(px);
  this.setCssVar('charsize-width', this.scrollPort_.characterSize.width + 'px');
  this.setCssVar('charsize-height',
                 this.scrollPort_.characterSize.height + 'px');
};

/**
 * Get the current font size.
 *
 * @return {number}
 */
hterm.Terminal.prototype.getFontSize = function() {
  return this.scrollPort_.getFontSize();
};

/**
 * Get the current font family.
 *
 * @return {string}
 */
hterm.Terminal.prototype.getFontFamily = function() {
  return this.scrollPort_.getFontFamily();
};

/**
 * Set the CSS "font-family" for this terminal.
 */
hterm.Terminal.prototype.syncFontFamily = function() {
  this.scrollPort_.setFontFamily(this.prefs_.get('font-family'),
                                 this.prefs_.get('font-smoothing'));
  this.syncBoldSafeState();
};

/**
 * Set this.mousePasteButton based on the mouse-paste-button pref,
 * autodetecting if necessary.
 */
hterm.Terminal.prototype.syncMousePasteButton = function() {
  var button = this.prefs_.get('mouse-paste-button');
  if (typeof button == 'number') {
    this.mousePasteButton = button;
    return;
  }

  if (hterm.os != 'linux') {
    this.mousePasteButton = 1;  // Middle mouse button.
  } else {
    this.mousePasteButton = 2;  // Right mouse button.
  }
};

/**
 * Enable or disable bold based on the enable-bold pref, autodetecting if
 * necessary.
 */
hterm.Terminal.prototype.syncBoldSafeState = function() {
  var enableBold = this.prefs_.get('enable-bold');
  if (enableBold !== null) {
    this.primaryScreen_.textAttributes.enableBold = enableBold;
    this.alternateScreen_.textAttributes.enableBold = enableBold;
    return;
  }

  var normalSize = this.scrollPort_.measureCharacterSize();
  var boldSize = this.scrollPort_.measureCharacterSize('bold');

  var isBoldSafe = normalSize.equals(boldSize);
  if (!isBoldSafe) {
    console.warn('Bold characters disabled: Size of bold weight differs ' +
                 'from normal.  Font family is: ' +
                 this.scrollPort_.getFontFamily());
  }

  this.primaryScreen_.textAttributes.enableBold = isBoldSafe;
  this.alternateScreen_.textAttributes.enableBold = isBoldSafe;
};

/**
 * Control text blinking behavior.
 *
 * @param {boolean=} state Whether to enable support for blinking text.
 */
hterm.Terminal.prototype.setTextBlink = function(state) {
  if (state === undefined)
    state = this.prefs_.get('enable-blink');
  this.setCssVar('blink-node-duration', state ? '0.7s' : '0');
};

/**
 * Set the mouse cursor style based on the current terminal mode.
 */
hterm.Terminal.prototype.syncMouseStyle = function() {
  this.setCssVar('mouse-cursor-style',
                 this.vt.mouseReport == this.vt.MOUSE_REPORT_DISABLED ?
                     'var(--hterm-mouse-cursor-text)' :
                     'var(--hterm-mouse-cursor-default)');
};

/**
 * Return a copy of the current cursor position.
 *
 * @return {hterm.RowCol} The RowCol object representing the current position.
 */
hterm.Terminal.prototype.saveCursor = function() {
  return this.screen_.cursorPosition.clone();
};

/**
 * Return the current text attributes.
 *
 * @return {string}
 */
hterm.Terminal.prototype.getTextAttributes = function() {
  return this.screen_.textAttributes;
};

/**
 * Set the text attributes.
 *
 * @param {string} textAttributes The attributes to set.
 */
hterm.Terminal.prototype.setTextAttributes = function(textAttributes) {
  this.screen_.textAttributes = textAttributes;
};

/**
 * Return the current browser zoom factor applied to the terminal.
 *
 * @return {number} The current browser zoom factor.
 */
hterm.Terminal.prototype.getZoomFactor = function() {
  return this.scrollPort_.characterSize.zoomFactor;
};

/**
 * Change the title of this terminal's window.
 *
 * @param {string} title The title to set.
 */
hterm.Terminal.prototype.setWindowTitle = function(title) {
  window.document.title = title;
};

/**
 * Restore a previously saved cursor position.
 *
 * @param {hterm.RowCol} cursor The position to restore.
 */
hterm.Terminal.prototype.restoreCursor = function(cursor) {
  var row = lib.f.clamp(cursor.row, 0, this.screenSize.height - 1);
  var column = lib.f.clamp(cursor.column, 0, this.screenSize.width - 1);
  this.screen_.setCursorPosition(row, column);
  if (cursor.column > column ||
      cursor.column == column && cursor.overflow) {
    this.screen_.cursorPosition.overflow = true;
  }
};

/**
 * Clear the cursor's overflow flag.
 */
hterm.Terminal.prototype.clearCursorOverflow = function() {
  this.screen_.cursorPosition.overflow = false;
};

/**
 * Save the current cursor state to the corresponding screens.
 *
 * See the hterm.Screen.CursorState class for more details.
 *
 * @param {boolean=} both If true, update both screens, else only update the
 *     current screen.
 */
hterm.Terminal.prototype.saveCursorAndState = function(both) {
  if (both) {
    this.primaryScreen_.saveCursorAndState(this.vt);
    this.alternateScreen_.saveCursorAndState(this.vt);
  } else
    this.screen_.saveCursorAndState(this.vt);
};

/**
 * Restore the saved cursor state in the corresponding screens.
 *
 * See the hterm.Screen.CursorState class for more details.
 *
 * @param {boolean=} both If true, update both screens, else only update the
 *     current screen.
 */
hterm.Terminal.prototype.restoreCursorAndState = function(both) {
  if (both) {
    this.primaryScreen_.restoreCursorAndState(this.vt);
    this.alternateScreen_.restoreCursorAndState(this.vt);
  } else
    this.screen_.restoreCursorAndState(this.vt);
};

/**
 * Sets the cursor shape
 *
 * @param {string} shape The shape to set.
 */
hterm.Terminal.prototype.setCursorShape = function(shape) {
  this.cursorShape_ = shape;
  this.restyleCursor_();
};

/**
 * Get the cursor shape
 *
 * @return {string}
 */
hterm.Terminal.prototype.getCursorShape = function() {
  return this.cursorShape_;
};

/**
 * Set the width of the terminal, resizing the UI to match.
 *
 * @param {number} columnCount
 */
hterm.Terminal.prototype.setWidth = function(columnCount) {
  if (columnCount == null) {
    this.div_.style.width = '100%';
    return;
  }

  this.div_.style.width = Math.ceil(
      this.scrollPort_.characterSize.width *
      columnCount + this.scrollPort_.currentScrollbarWidthPx) + 'px';
  this.realizeSize_(columnCount, this.screenSize.height);
  this.scheduleSyncCursorPosition_();
};

/**
 * Set the height of the terminal, resizing the UI to match.
 *
 * @param {number} rowCount The height in rows.
 */
hterm.Terminal.prototype.setHeight = function(rowCount) {
  if (rowCount == null) {
    this.div_.style.height = '100%';
    return;
  }

  this.div_.style.height =
      this.scrollPort_.characterSize.height * rowCount + 'px';
  this.realizeSize_(this.screenSize.width, rowCount);
  this.scheduleSyncCursorPosition_();
};

/**
 * Deal with terminal size changes.
 *
 * @param {number} columnCount The number of columns.
 * @param {number} rowCount The number of rows.
 */
hterm.Terminal.prototype.realizeSize_ = function(columnCount, rowCount) {
  if (columnCount != this.screenSize.width)
    this.realizeWidth_(columnCount);

  if (rowCount != this.screenSize.height)
    this.realizeHeight_(rowCount);

  // Send new terminal size to plugin.
  this.io.onTerminalResize_(columnCount, rowCount);
};

/**
 * Deal with terminal width changes.
 *
 * This function does what needs to be done when the terminal width changes
 * out from under us.  It happens here rather than in onResize_() because this
 * code may need to run synchronously to handle programmatic changes of
 * terminal width.
 *
 * Relying on the browser to send us an async resize event means we may not be
 * in the correct state yet when the next escape sequence hits.
 *
 * @param {number} columnCount The number of columns.
 */
hterm.Terminal.prototype.realizeWidth_ = function(columnCount) {
  if (columnCount <= 0)
    throw new Error('Attempt to realize bad width: ' + columnCount);

  var deltaColumns = columnCount - this.screen_.getWidth();

  this.screenSize.width = columnCount;
  this.screen_.setColumnCount(columnCount);

  if (deltaColumns > 0) {
    if (this.defaultTabStops)
      this.setDefaultTabStops(this.screenSize.width - deltaColumns);
  } else {
    for (var i = this.tabStops_.length - 1; i >= 0; i--) {
      if (this.tabStops_[i] < columnCount)
        break;

      this.tabStops_.pop();
    }
  }

  this.screen_.setColumnCount(this.screenSize.width);
};

/**
 * Deal with terminal height changes.
 *
 * This function does what needs to be done when the terminal height changes
 * out from under us.  It happens here rather than in onResize_() because this
 * code may need to run synchronously to handle programmatic changes of
 * terminal height.
 *
 * Relying on the browser to send us an async resize event means we may not be
 * in the correct state yet when the next escape sequence hits.
 *
 * @param {number} rowCount The number of rows.
 */
hterm.Terminal.prototype.realizeHeight_ = function(rowCount) {
  if (rowCount <= 0)
    throw new Error('Attempt to realize bad height: ' + rowCount);

  var deltaRows = rowCount - this.screen_.getHeight();

  this.screenSize.height = rowCount;

  var cursor = this.saveCursor();

  if (deltaRows < 0) {
    // Screen got smaller.
    deltaRows *= -1;
    while (deltaRows) {
      var lastRow = this.getRowCount() - 1;
      if (lastRow - this.scrollbackRows_.length == cursor.row)
        break;

      if (this.getRowText(lastRow))
        break;

      this.screen_.popRow();
      deltaRows--;
    }

    var ary = this.screen_.shiftRows(deltaRows);
    this.scrollbackRows_.push.apply(this.scrollbackRows_, ary);

    // We just removed rows from the top of the screen, we need to update
    // the cursor to match.
    cursor.row = Math.max(cursor.row - deltaRows, 0);
  } else if (deltaRows > 0) {
    // Screen got larger.

    if (deltaRows <= this.scrollbackRows_.length) {
      var scrollbackCount = Math.min(deltaRows, this.scrollbackRows_.length);
      var rows = this.scrollbackRows_.splice(
          this.scrollbackRows_.length - scrollbackCount, scrollbackCount);
      this.screen_.unshiftRows(rows);
      deltaRows -= scrollbackCount;
      cursor.row += scrollbackCount;
    }

    if (deltaRows)
      this.appendRows_(deltaRows);
  }

  this.setVTScrollRegion(null, null);
  this.restoreCursor(cursor);
};

/**
 * Scroll the terminal to the top of the scrollback buffer.
 */
hterm.Terminal.prototype.scrollHome = function() {
  this.scrollPort_.scrollRowToTop(0);
};

/**
 * Scroll the terminal to the end.
 */
hterm.Terminal.prototype.scrollEnd = function() {
  this.scrollPort_.scrollRowToBottom(this.getRowCount());
};

/**
 * Scroll the terminal one page up (minus one line) relative to the current
 * position.
 */
hterm.Terminal.prototype.scrollPageUp = function() {
  this.scrollPort_.scrollPageUp();
};

/**
 * Scroll the terminal one page down (minus one line) relative to the current
 * position.
 */
hterm.Terminal.prototype.scrollPageDown = function() {
  this.scrollPort_.scrollPageDown();
};

/**
 * Scroll the terminal one line up relative to the current position.
 */
hterm.Terminal.prototype.scrollLineUp = function() {
  var i = this.scrollPort_.getTopRowIndex();
  this.scrollPort_.scrollRowToTop(i - 1);
};

/**
 * Scroll the terminal one line down relative to the current position.
 */
hterm.Terminal.prototype.scrollLineDown = function() {
  var i = this.scrollPort_.getTopRowIndex();
  this.scrollPort_.scrollRowToTop(i + 1);
};

/**
 * Clear primary screen, secondary screen, and the scrollback buffer.
 */
hterm.Terminal.prototype.wipeContents = function() {
  this.clearHome(this.primaryScreen_);
  this.clearHome(this.alternateScreen_);

  this.clearScrollback();
};

/**
 * Clear scrollback buffer.
 */
hterm.Terminal.prototype.clearScrollback = function() {
  // Move to the end of the buffer in case the screen was scrolled back.
  // We're going to throw it away which would leave the display invalid.
  this.scrollEnd();

  this.scrollbackRows_.length = 0;
  this.scrollPort_.resetCache();

  [this.primaryScreen_, this.alternateScreen_].forEach((screen) => {
    const bottom = screen.getHeight();
    this.renumberRows_(0, bottom, screen);
  });

  this.syncCursorPosition_();
  this.scrollPort_.invalidate();
};

/**
 * Full terminal reset.
 *
 * Perform a full reset to the default values listed in
 * https://vt100.net/docs/vt510-rm/RIS.html
 */
hterm.Terminal.prototype.reset = function() {
  this.vt.reset();

  this.clearAllTabStops();
  this.setDefaultTabStops();

  const resetScreen = (screen) => {
    // We want to make sure to reset the attributes before we clear the screen.
    // The attributes might be used to initialize default/empty rows.
    screen.textAttributes.reset();
    screen.textAttributes.resetColorPalette();
    this.clearHome(screen);
    screen.saveCursorAndState(this.vt);
  };
  resetScreen(this.primaryScreen_);
  resetScreen(this.alternateScreen_);

  // Reset terminal options to their default values.
  this.options_ = new hterm.Options();
  this.setCursorBlink(!!this.prefs_.get('cursor-blink'));

  this.setVTScrollRegion(null, null);

  this.setCursorVisible(true);
};

/**
 * Soft terminal reset.
 *
 * Perform a soft reset to the default values listed in
 * http://www.vt100.net/docs/vt510-rm/DECSTR#T5-9
 */
hterm.Terminal.prototype.softReset = function() {
  this.vt.reset();

  // Reset terminal options to their default values.
  this.options_ = new hterm.Options();

  // We show the cursor on soft reset but do not alter the blink state.
  this.options_.cursorBlink = !!this.timeouts_.cursorBlink;

  const resetScreen = (screen) => {
    // Xterm also resets the color palette on soft reset, even though it doesn't
    // seem to be documented anywhere.
    screen.textAttributes.reset();
    screen.textAttributes.resetColorPalette();
    screen.saveCursorAndState(this.vt);
  };
  resetScreen(this.primaryScreen_);
  resetScreen(this.alternateScreen_);

  // The xterm man page explicitly says this will happen on soft reset.
  this.setVTScrollRegion(null, null);

  // Xterm also shows the cursor on soft reset, but does not alter the blink
  // state.
  this.setCursorVisible(true);
};

/**
 * Move the cursor forward to the next tab stop, or to the last column
 * if no more tab stops are set.
 */
hterm.Terminal.prototype.forwardTabStop = function() {
  var column = this.screen_.cursorPosition.column;

  for (var i = 0; i < this.tabStops_.length; i++) {
    if (this.tabStops_[i] > column) {
      this.setCursorColumn(this.tabStops_[i]);
      return;
    }
  }

  // xterm does not clear the overflow flag on HT or CHT.
  var overflow = this.screen_.cursorPosition.overflow;
  this.setCursorColumn(this.screenSize.width - 1);
  this.screen_.cursorPosition.overflow = overflow;
};

/**
 * Move the cursor backward to the previous tab stop, or to the first column
 * if no previous tab stops are set.
 */
hterm.Terminal.prototype.backwardTabStop = function() {
  var column = this.screen_.cursorPosition.column;

  for (var i = this.tabStops_.length - 1; i >= 0; i--) {
    if (this.tabStops_[i] < column) {
      this.setCursorColumn(this.tabStops_[i]);
      return;
    }
  }

  this.setCursorColumn(1);
};

/**
 * Set a tab stop at the given column.
 *
 * @param {integer} column Zero based column.
 */
hterm.Terminal.prototype.setTabStop = function(column) {
  for (var i = this.tabStops_.length - 1; i >= 0; i--) {
    if (this.tabStops_[i] == column)
      return;

    if (this.tabStops_[i] < column) {
      this.tabStops_.splice(i + 1, 0, column);
      return;
    }
  }

  this.tabStops_.splice(0, 0, column);
};

/**
 * Clear the tab stop at the current cursor position.
 *
 * No effect if there is no tab stop at the current cursor position.
 */
hterm.Terminal.prototype.clearTabStopAtCursor = function() {
  var column = this.screen_.cursorPosition.column;

  var i = this.tabStops_.indexOf(column);
  if (i == -1)
    return;

  this.tabStops_.splice(i, 1);
};

/**
 * Clear all tab stops.
 */
hterm.Terminal.prototype.clearAllTabStops = function() {
  this.tabStops_.length = 0;
  this.defaultTabStops = false;
};

/**
 * Set up the default tab stops, starting from a given column.
 *
 * This sets a tabstop every (column % this.tabWidth) column, starting
 * from the specified column, or 0 if no column is provided.  It also flags
 * future resizes to set them up.
 *
 * This does not clear the existing tab stops first, use clearAllTabStops
 * for that.
 *
 * @param {integer} opt_start Optional starting zero based starting column, useful
 *     for filling out missing tab stops when the terminal is resized.
 */
hterm.Terminal.prototype.setDefaultTabStops = function(opt_start) {
  var start = opt_start || 0;
  var w = this.tabWidth;
  // Round start up to a default tab stop.
  start = start - 1 - ((start - 1) % w) + w;
  for (var i = start; i < this.screenSize.width; i += w) {
    this.setTabStop(i);
  }

  this.defaultTabStops = true;
};

/**
 * Interpret a sequence of characters.
 *
 * Incomplete escape sequences are buffered until the next call.
 *
 * @param {string} str Sequence of characters to interpret or pass through.
 */
hterm.Terminal.prototype.interpret = function(str) {
  this.scheduleSyncCursorPosition_();
  this.vt.interpret(str);
};

/**
 * Take over the given DIV for use as the terminal display.
 *
 * @param {HTMLDivElement} div The div to use as the terminal display.
 */
hterm.Terminal.prototype.decorate = function(div) {
  const charset = div.ownerDocument.characterSet.toLowerCase();
  if (charset != 'utf-8') {
    console.warn(`Document encoding should be set to utf-8, not "${charset}";` +
                 ` Add <meta charset='utf-8'/> to your HTML <head> to fix.`);
  }

  this.div_ = div;

  this.accessibilityReader_ = new hterm.AccessibilityReader(div);

  this.scrollPort_.decorate(div);
  this.scrollPort_.setBackgroundImage(this.prefs_.get('background-image'));
  this.scrollPort_.setBackgroundSize(this.prefs_.get('background-size'));
  this.scrollPort_.setBackgroundPosition(
      this.prefs_.get('background-position'));
  this.scrollPort_.setUserCssUrl(this.prefs_.get('user-css'));
  this.scrollPort_.setUserCssText(this.prefs_.get('user-css-text'));
  this.scrollPort_.setAccessibilityReader(this.accessibilityReader_);

  this.div_.focus = this.focus.bind(this);

  this.setFontSize(this.prefs_.get('font-size'));
  this.syncFontFamily();

  this.setScrollbarVisible(this.prefs_.get('scrollbar-visible'));
  this.setScrollWheelMoveMultipler(
      this.prefs_.get('scroll-wheel-move-multiplier'));

  this.document_ = this.scrollPort_.getDocument();
  this.accessibilityReader_.decorate(this.document_);

  this.document_.body.oncontextmenu = function() { return false; };
  this.contextMenu.setDocument(this.document_);

  var onMouse = this.onMouse_.bind(this);
  var screenNode = this.scrollPort_.getScreenNode();
  screenNode.addEventListener('mousedown', onMouse);
  screenNode.addEventListener('mouseup', onMouse);
  screenNode.addEventListener('mousemove', onMouse);
  this.scrollPort_.onScrollWheel = onMouse;

  screenNode.addEventListener('keydown', this.onKeyboardActivity_.bind(this));

  screenNode.addEventListener(
      'focus', this.onFocusChange_.bind(this, true));
  // Listen for mousedown events on the screenNode as in FF the focus
  // events don't bubble.
  screenNode.addEventListener('mousedown', function() {
    setTimeout(this.onFocusChange_.bind(this, true));
  }.bind(this));

  screenNode.addEventListener(
      'blur', this.onFocusChange_.bind(this, false));

  var style = this.document_.createElement('style');
  style.textContent =
      ('.cursor-node[focus="false"] {' +
       '  box-sizing: border-box;' +
       '  background-color: transparent !important;' +
       '  border-width: 2px;' +
       '  border-style: solid;' +
       '}' +
       'menu {' +
       '  margin: 0;' +
       '  padding: 0;' +
       '  cursor: var(--hterm-mouse-cursor-pointer);' +
       '}' +
       'menuitem {' +
       '  white-space: nowrap;' +
       '  border-bottom: 1px dashed;' +
       '  display: block;' +
       '  padding: 0.3em 0.3em 0 0.3em;' +
       '}' +
       'menuitem.separator {' +
       '  border-bottom: none;' +
       '  height: 0.5em;' +
       '  padding: 0;' +
       '}' +
       'menuitem:hover {' +
       '  color: var(--hterm-cursor-color);' +
       '}' +
       '.wc-node {' +
       '  display: inline-block;' +
       '  text-align: center;' +
       '  width: calc(var(--hterm-charsize-width) * 2);' +
       '  line-height: var(--hterm-charsize-height);' +
       '}' +
       ':root {' +
       '  --hterm-charsize-width: ' + this.scrollPort_.characterSize.width + 'px;' +
       '  --hterm-charsize-height: ' + this.scrollPort_.characterSize.height + 'px;' +
       // Default position hides the cursor for when the window is initializing.
       '  --hterm-cursor-offset-col: -1;' +
       '  --hterm-cursor-offset-row: -1;' +
       '  --hterm-blink-node-duration: 0.7s;' +
       '  --hterm-mouse-cursor-default: default;' +
       '  --hterm-mouse-cursor-text: text;' +
       '  --hterm-mouse-cursor-pointer: pointer;' +
       '  --hterm-mouse-cursor-style: var(--hterm-mouse-cursor-text);' +
       '}' +
       '.uri-node:hover {' +
       '  text-decoration: underline;' +
       '  cursor: var(--hterm-mouse-cursor-pointer);' +
       '}' +
       '@keyframes blink {' +
       '  from { opacity: 1.0; }' +
       '  to { opacity: 0.0; }' +
       '}' +
       '.blink-node {' +
       '  animation-name: blink;' +
       '  animation-duration: var(--hterm-blink-node-duration);' +
       '  animation-iteration-count: infinite;' +
       '  animation-timing-function: ease-in-out;' +
       '  animation-direction: alternate;' +
       '}');
  // Insert this stock style as the first node so that any user styles will
  // override w/out having to use !important everywhere.  The rules above mix
  // runtime variables with default ones designed to be overridden by the user,
  // but we can wait for a concrete case from the users to determine the best
  // way to split the sheet up to before & after the user-css settings.
  this.document_.head.insertBefore(style, this.document_.head.firstChild);

  this.cursorNode_ = this.document_.createElement('div');
  this.cursorNode_.id = 'hterm:terminal-cursor';
  this.cursorNode_.className = 'cursor-node';
  this.cursorNode_.style.cssText =
      ('position: absolute;' +
       'left: calc(var(--hterm-charsize-width) * var(--hterm-cursor-offset-col));' +
       'top: calc(var(--hterm-charsize-height) * var(--hterm-cursor-offset-row));' +
       'display: ' + (this.options_.cursorVisible ? '' : 'none') + ';' +
       'width: var(--hterm-charsize-width);' +
       'height: var(--hterm-charsize-height);' +
       'background-color: var(--hterm-cursor-color);' +
       'border-color: var(--hterm-cursor-color);' +
       '-webkit-transition: opacity, background-color 100ms linear;' +
       '-moz-transition: opacity, background-color 100ms linear;');

  this.setCursorColor();
  this.setCursorBlink(!!this.prefs_.get('cursor-blink'));
  this.restyleCursor_();

  this.document_.body.appendChild(this.cursorNode_);

  // When 'enableMouseDragScroll' is off we reposition this element directly
  // under the mouse cursor after a click.  This makes Chrome associate
  // subsequent mousemove events with the scroll-blocker.  Since the
  // scroll-blocker is a peer (not a child) of the scrollport, the mousemove
  // events do not cause the scrollport to scroll.
  //
  // It's a hack, but it's the cleanest way I could find.
  this.scrollBlockerNode_ = this.document_.createElement('div');
  this.scrollBlockerNode_.id = 'hterm:mouse-drag-scroll-blocker';
  this.scrollBlockerNode_.setAttribute('aria-hidden', 'true');
  this.scrollBlockerNode_.style.cssText =
      ('position: absolute;' +
       'top: -99px;' +
       'display: block;' +
       'width: 10px;' +
       'height: 10px;');
  this.document_.body.appendChild(this.scrollBlockerNode_);

  this.scrollPort_.onScrollWheel = onMouse;
  ['mousedown', 'mouseup', 'mousemove', 'click', 'dblclick',
   ].forEach(function(event) {
       this.scrollBlockerNode_.addEventListener(event, onMouse);
       this.cursorNode_.addEventListener(event, onMouse);
       this.document_.addEventListener(event, onMouse);
     }.bind(this));

  this.cursorNode_.addEventListener('mousedown', function() {
      setTimeout(this.focus.bind(this));
    }.bind(this));

  this.setReverseVideo(false);

  this.scrollPort_.focus();
  this.scrollPort_.scheduleRedraw();
};

/**
 * Return the HTML document that contains the terminal DOM nodes.
 *
 * @return {HTMLDocument}
 */
hterm.Terminal.prototype.getDocument = function() {
  return this.document_;
};

/**
 * Focus the terminal.
 */
hterm.Terminal.prototype.focus = function() {
  this.scrollPort_.focus();
};

/**
 * Return the HTML Element for a given row index.
 *
 * This is a method from the RowProvider interface.  The ScrollPort uses
 * it to fetch rows on demand as they are scrolled into view.
 *
 * TODO(rginda): Consider saving scrollback rows as (HTML source, text content)
 * pairs to conserve memory.
 *
 * @param {integer} index The zero-based row index, measured relative to the
 *     start of the scrollback buffer.  On-screen rows will always have the
 *     largest indices.
 * @return {HTMLElement} The 'x-row' element containing for the requested row.
 */
hterm.Terminal.prototype.getRowNode = function(index) {
  if (index < this.scrollbackRows_.length)
    return this.scrollbackRows_[index];

  var screenIndex = index - this.scrollbackRows_.length;
  return this.screen_.rowsArray[screenIndex];
};

/**
 * Return the text content for a given range of rows.
 *
 * This is a method from the RowProvider interface.  The ScrollPort uses
 * it to fetch text content on demand when the user attempts to copy their
 * selection to the clipboard.
 *
 * @param {integer} start The zero-based row index to start from, measured
 *     relative to the start of the scrollback buffer.  On-screen rows will
 *     always have the largest indices.
 * @param {integer} end The zero-based row index to end on, measured
 *     relative to the start of the scrollback buffer.
 * @return {string} A single string containing the text value of the range of
 *     rows.  Lines will be newline delimited, with no trailing newline.
 */
hterm.Terminal.prototype.getRowsText = function(start, end) {
  var ary = [];
  for (var i = start; i < end; i++) {
    var node = this.getRowNode(i);
    ary.push(node.textContent);
    if (i < end - 1 && !node.getAttribute('line-overflow'))
      ary.push('\n');
  }

  return ary.join('');
};

/**
 * Return the text content for a given row.
 *
 * This is a method from the RowProvider interface.  The ScrollPort uses
 * it to fetch text content on demand when the user attempts to copy their
 * selection to the clipboard.
 *
 * @param {integer} index The zero-based row index to return, measured
 *     relative to the start of the scrollback buffer.  On-screen rows will
 *     always have the largest indices.
 * @return {string} A string containing the text value of the selected row.
 */
hterm.Terminal.prototype.getRowText = function(index) {
  var node = this.getRowNode(index);
  return node.textContent;
};

/**
 * Return the total number of rows in the addressable screen and in the
 * scrollback buffer of this terminal.
 *
 * This is a method from the RowProvider interface.  The ScrollPort uses
 * it to compute the size of the scrollbar.
 *
 * @return {integer} The number of rows in this terminal.
 */
hterm.Terminal.prototype.getRowCount = function() {
  return this.scrollbackRows_.length + this.screen_.rowsArray.length;
};

/**
 * Create DOM nodes for new rows and append them to the end of the terminal.
 *
 * This is the only correct way to add a new DOM node for a row.  Notice that
 * the new row is appended to the bottom of the list of rows, and does not
 * require renumbering (of the rowIndex property) of previous rows.
 *
 * If you think you want a new blank row somewhere in the middle of the
 * terminal, look into moveRows_().
 *
 * This method does not pay attention to vtScrollTop/Bottom, since you should
 * be using moveRows() in cases where they would matter.
 *
 * The cursor will be positioned at column 0 of the first inserted line.
 *
 * @param {number} count The number of rows to created.
 */
hterm.Terminal.prototype.appendRows_ = function(count) {
  var cursorRow = this.screen_.rowsArray.length;
  var offset = this.scrollbackRows_.length + cursorRow;
  for (var i = 0; i < count; i++) {
    var row = this.document_.createElement('x-row');
    row.appendChild(this.document_.createTextNode(''));
    row.rowIndex = offset + i;
    this.screen_.pushRow(row);
  }

  var extraRows = this.screen_.rowsArray.length - this.screenSize.height;
  if (extraRows > 0) {
    var ary = this.screen_.shiftRows(extraRows);
    Array.prototype.push.apply(this.scrollbackRows_, ary);
    if (this.scrollPort_.isScrolledEnd)
      this.scheduleScrollDown_();
  }

  if (cursorRow >= this.screen_.rowsArray.length)
    cursorRow = this.screen_.rowsArray.length - 1;

  this.setAbsoluteCursorPosition(cursorRow, 0);
};

/**
 * Relocate rows from one part of the addressable screen to another.
 *
 * This is used to recycle rows during VT scrolls (those which are driven
 * by VT commands, rather than by the user manipulating the scrollbar.)
 *
 * In this case, the blank lines scrolled into the scroll region are made of
 * the nodes we scrolled off.  These have their rowIndex properties carefully
 * renumbered so as not to confuse the ScrollPort.
 *
 * @param {number} fromIndex The start index.
 * @param {number} count The number of rows to move.
 * @param {number} toIndex The destination index.
 */
hterm.Terminal.prototype.moveRows_ = function(fromIndex, count, toIndex) {
  var ary = this.screen_.removeRows(fromIndex, count);
  this.screen_.insertRows(toIndex, ary);

  var start, end;
  if (fromIndex < toIndex) {
    start = fromIndex;
    end = toIndex + count;
  } else {
    start = toIndex;
    end = fromIndex + count;
  }

  this.renumberRows_(start, end);
  this.scrollPort_.scheduleInvalidate();
};

/**
 * Renumber the rowIndex property of the given range of rows.
 *
 * The start and end indices are relative to the screen, not the scrollback.
 * Rows in the scrollback buffer cannot be renumbered.  Since they are not
 * addressable (you can't delete them, scroll them, etc), you should have
 * no need to renumber scrollback rows.
 *
 * @param {number} start The start index.
 * @param {number} end The end index.
 * @param {hterm.Screen} opt_screen The screen to renumber.
 */
hterm.Terminal.prototype.renumberRows_ = function(start, end, opt_screen) {
  var screen = opt_screen || this.screen_;

  var offset = this.scrollbackRows_.length;
  for (var i = start; i < end; i++) {
    screen.rowsArray[i].rowIndex = offset + i;
  }
};

/**
 * Print a string to the terminal.
 *
 * This respects the current insert and wraparound modes.  It will add new lines
 * to the end of the terminal, scrolling off the top into the scrollback buffer
 * if necessary.
 *
 * The string is *not* parsed for escape codes.  Use the interpret() method if
 * that's what you're after.
 *
 * @param{string} str The string to print.
 */
hterm.Terminal.prototype.print = function(str) {
  this.scheduleSyncCursorPosition_();

  // Basic accessibility output for the screen reader.
  this.accessibilityReader_.announce(str);

  var startOffset = 0;

  var strWidth = lib.wc.strWidth(str);
  // Fun edge case: If the string only contains zero width codepoints (like
  // combining characters), we make sure to iterate at least once below.
  if (strWidth == 0 && str)
    strWidth = 1;

  while (startOffset < strWidth) {
    if (this.options_.wraparound && this.screen_.cursorPosition.overflow) {
      this.screen_.commitLineOverflow();
      this.newLine(true);
    }

    var count = strWidth - startOffset;
    var didOverflow = false;
    var substr;

    if (this.screen_.cursorPosition.column + count >= this.screenSize.width) {
      didOverflow = true;
      count = this.screenSize.width - this.screen_.cursorPosition.column;
    }

    if (didOverflow && !this.options_.wraparound) {
      // If the string overflowed the line but wraparound is off, then the
      // last printed character should be the last of the string.
      // TODO: This will add to our problems with multibyte UTF-16 characters.
      substr = lib.wc.substr(str, startOffset, count - 1) +
          lib.wc.substr(str, strWidth - 1);
      count = strWidth;
    } else {
      substr = lib.wc.substr(str, startOffset, count);
    }

    var tokens = hterm.TextAttributes.splitWidecharString(substr);
    for (var i = 0; i < tokens.length; i++) {
      this.screen_.textAttributes.wcNode = tokens[i].wcNode;
      this.screen_.textAttributes.asciiNode = tokens[i].asciiNode;

      if (this.options_.insertMode) {
        this.screen_.insertString(tokens[i].str, tokens[i].wcStrWidth);
      } else {
        this.screen_.overwriteString(tokens[i].str, tokens[i].wcStrWidth);
      }
      this.screen_.textAttributes.wcNode = false;
      this.screen_.textAttributes.asciiNode = true;
    }

    this.screen_.maybeClipCurrentRow();
    startOffset += count;
  }

  if (this.scrollOnOutput_)
    this.scrollPort_.scrollRowToBottom(this.getRowCount());
};

/**
 * Set the VT scroll region.
 *
 * This also resets the cursor position to the absolute (0, 0) position, since
 * that's what xterm appears to do.
 *
 * Setting the scroll region to the full height of the terminal will clear
 * the scroll region.  This is *NOT* what most terminals do.  We're explicitly
 * going "off-spec" here because it makes `screen` and `tmux` overflow into the
 * local scrollback buffer, which means the scrollbars and shift-pgup/pgdn
 * continue to work as most users would expect.
 *
 * @param {integer} scrollTop The zero-based top of the scroll region.
 * @param {integer} scrollBottom The zero-based bottom of the scroll region,
 *     inclusive.
 */
hterm.Terminal.prototype.setVTScrollRegion = function(scrollTop, scrollBottom) {
  if (scrollTop == 0 && scrollBottom == this.screenSize.height - 1) {
    this.vtScrollTop_ = null;
    this.vtScrollBottom_ = null;
  } else {
    this.vtScrollTop_ = scrollTop;
    this.vtScrollBottom_ = scrollBottom;
  }
};

/**
 * Return the top row index according to the VT.
 *
 * This will return 0 unless the terminal has been told to restrict scrolling
 * to some lower row.  It is used for some VT cursor positioning and scrolling
 * commands.
 *
 * @return {integer} The topmost row in the terminal's scroll region.
 */
hterm.Terminal.prototype.getVTScrollTop = function() {
  if (this.vtScrollTop_ != null)
    return this.vtScrollTop_;

  return 0;
};

/**
 * Return the bottom row index according to the VT.
 *
 * This will return the height of the terminal unless the it has been told to
 * restrict scrolling to some higher row.  It is used for some VT cursor
 * positioning and scrolling commands.
 *
 * @return {integer} The bottom most row in the terminal's scroll region.
 */
hterm.Terminal.prototype.getVTScrollBottom = function() {
  if (this.vtScrollBottom_ != null)
    return this.vtScrollBottom_;

  return this.screenSize.height - 1;
};

/**
 * Process a '\n' character.
 *
 * If the cursor is on the final row of the terminal this will append a new
 * blank row to the screen and scroll the topmost row into the scrollback
 * buffer.
 *
 * Otherwise, this moves the cursor to column zero of the next row.
 *
 * @param {boolean=} dueToOverflow Whether the newline is due to wraparound of
 *     the terminal.
 */
hterm.Terminal.prototype.newLine = function(dueToOverflow = false) {
  if (!dueToOverflow)
    this.accessibilityReader_.newLine();

  var cursorAtEndOfScreen = (this.screen_.cursorPosition.row ==
                             this.screen_.rowsArray.length - 1);

  if (this.vtScrollBottom_ != null) {
    // A VT Scroll region is active, we never append new rows.
    if (this.screen_.cursorPosition.row == this.vtScrollBottom_) {
      // We're at the end of the VT Scroll Region, perform a VT scroll.
      this.vtScrollUp(1);
      this.setAbsoluteCursorPosition(this.screen_.cursorPosition.row, 0);
    } else if (cursorAtEndOfScreen) {
      // We're at the end of the screen, the only thing to do is put the
      // cursor to column 0.
      this.setAbsoluteCursorPosition(this.screen_.cursorPosition.row, 0);
    } else {
      // Anywhere else, advance the cursor row, and reset the column.
      this.setAbsoluteCursorPosition(this.screen_.cursorPosition.row + 1, 0);
    }
  } else if (cursorAtEndOfScreen) {
    // We're at the end of the screen.  Append a new row to the terminal,
    // shifting the top row into the scrollback.
    this.appendRows_(1);
  } else {
    // Anywhere else in the screen just moves the cursor.
    this.setAbsoluteCursorPosition(this.screen_.cursorPosition.row + 1, 0);
  }
};

/**
 * Like newLine(), except maintain the cursor column.
 */
hterm.Terminal.prototype.lineFeed = function() {
  var column = this.screen_.cursorPosition.column;
  this.newLine();
  this.setCursorColumn(column);
};

/**
 * If autoCarriageReturn is set then newLine(), else lineFeed().
 */
hterm.Terminal.prototype.formFeed = function() {
  if (this.options_.autoCarriageReturn) {
    this.newLine();
  } else {
    this.lineFeed();
  }
};

/**
 * Move the cursor up one row, possibly inserting a blank line.
 *
 * The cursor column is not changed.
 */
hterm.Terminal.prototype.reverseLineFeed = function() {
  var scrollTop = this.getVTScrollTop();
  var currentRow = this.screen_.cursorPosition.row;

  if (currentRow == scrollTop) {
    this.insertLines(1);
  } else {
    this.setAbsoluteCursorRow(currentRow - 1);
  }
};

/**
 * Replace all characters to the left of the current cursor with the space
 * character.
 *
 * TODO(rginda): This should probably *remove* the characters (not just replace
 * with a space) if there are no characters at or beyond the current cursor
 * position.
 */
hterm.Terminal.prototype.eraseToLeft = function() {
  var cursor = this.saveCursor();
  this.setCursorColumn(0);
  const count = cursor.column + 1;
  this.screen_.overwriteString(lib.f.getWhitespace(count), count);
  this.restoreCursor(cursor);
};

/**
 * Erase a given number of characters to the right of the cursor.
 *
 * The cursor position is unchanged.
 *
 * If the current background color is not the default background color this
 * will insert spaces rather than delete.  This is unfortunate because the
 * trailing space will affect text selection, but it's difficult to come up
 * with a way to style empty space that wouldn't trip up the hterm.Screen
 * code.
 *
 * eraseToRight is ignored in the presence of a cursor overflow.  This deviates
 * from xterm, but agrees with gnome-terminal and konsole, xfce4-terminal.  See
 * crbug.com/232390 for details.
 *
 * @param {number} opt_count The number of characters to erase.
 */
hterm.Terminal.prototype.eraseToRight = function(opt_count) {
  if (this.screen_.cursorPosition.overflow)
    return;

  var maxCount = this.screenSize.width - this.screen_.cursorPosition.column;
  var count = opt_count ? Math.min(opt_count, maxCount) : maxCount;

  if (this.screen_.textAttributes.background ===
      this.screen_.textAttributes.DEFAULT_COLOR) {
    var cursorRow = this.screen_.rowsArray[this.screen_.cursorPosition.row];
    if (hterm.TextAttributes.nodeWidth(cursorRow) <=
        this.screen_.cursorPosition.column + count) {
      this.screen_.deleteChars(count);
      this.clearCursorOverflow();
      return;
    }
  }

  var cursor = this.saveCursor();
  this.screen_.overwriteString(lib.f.getWhitespace(count), count);
  this.restoreCursor(cursor);
  this.clearCursorOverflow();
};

/**
 * Erase the current line.
 *
 * The cursor position is unchanged.
 */
hterm.Terminal.prototype.eraseLine = function() {
  var cursor = this.saveCursor();
  this.screen_.clearCursorRow();
  this.restoreCursor(cursor);
  this.clearCursorOverflow();
};

/**
 * Erase all characters from the start of the screen to the current cursor
 * position, regardless of scroll region.
 *
 * The cursor position is unchanged.
 */
hterm.Terminal.prototype.eraseAbove = function() {
  var cursor = this.saveCursor();

  this.eraseToLeft();

  for (var i = 0; i < cursor.row; i++) {
    this.setAbsoluteCursorPosition(i, 0);
    this.screen_.clearCursorRow();
  }

  this.restoreCursor(cursor);
  this.clearCursorOverflow();
};

/**
 * Erase all characters from the current cursor position to the end of the
 * screen, regardless of scroll region.
 *
 * The cursor position is unchanged.
 */
hterm.Terminal.prototype.eraseBelow = function() {
  var cursor = this.saveCursor();

  this.eraseToRight();

  var bottom = this.screenSize.height - 1;
  for (var i = cursor.row + 1; i <= bottom; i++) {
    this.setAbsoluteCursorPosition(i, 0);
    this.screen_.clearCursorRow();
  }

  this.restoreCursor(cursor);
  this.clearCursorOverflow();
};

/**
 * Fill the terminal with a given character.
 *
 * This methods does not respect the VT scroll region.
 *
 * @param {string} ch The character to use for the fill.
 */
hterm.Terminal.prototype.fill = function(ch) {
  var cursor = this.saveCursor();

  this.setAbsoluteCursorPosition(0, 0);
  for (var row = 0; row < this.screenSize.height; row++) {
    for (var col = 0; col < this.screenSize.width; col++) {
      this.setAbsoluteCursorPosition(row, col);
      this.screen_.overwriteString(ch, 1);
    }
  }

  this.restoreCursor(cursor);
};

/**
 * Erase the entire display and leave the cursor at (0, 0).
 *
 * This does not respect the scroll region.
 *
 * @param {hterm.Screen} opt_screen Optional screen to operate on.  Defaults
 *     to the current screen.
 */
hterm.Terminal.prototype.clearHome = function(opt_screen) {
  var screen = opt_screen || this.screen_;
  var bottom = screen.getHeight();

  this.accessibilityReader_.clear();

  if (bottom == 0) {
    // Empty screen, nothing to do.
    return;
  }

  for (var i = 0; i < bottom; i++) {
    screen.setCursorPosition(i, 0);
    screen.clearCursorRow();
  }

  screen.setCursorPosition(0, 0);
};

/**
 * Erase the entire display without changing the cursor position.
 *
 * The cursor position is unchanged.  This does not respect the scroll
 * region.
 *
 * @param {hterm.Screen} opt_screen Optional screen to operate on.  Defaults
 *     to the current screen.
 */
hterm.Terminal.prototype.clear = function(opt_screen) {
  var screen = opt_screen || this.screen_;
  var cursor = screen.cursorPosition.clone();
  this.clearHome(screen);
  screen.setCursorPosition(cursor.row, cursor.column);
};

/**
 * VT command to insert lines at the current cursor row.
 *
 * This respects the current scroll region.  Rows pushed off the bottom are
 * lost (they won't show up in the scrollback buffer).
 *
 * @param {integer} count The number of lines to insert.
 */
hterm.Terminal.prototype.insertLines = function(count) {
  var cursorRow = this.screen_.cursorPosition.row;

  var bottom = this.getVTScrollBottom();
  count = Math.min(count, bottom - cursorRow);

  // The moveCount is the number of rows we need to relocate to make room for
  // the new row(s).  The count is the distance to move them.
  var moveCount = bottom - cursorRow - count + 1;
  if (moveCount)
    this.moveRows_(cursorRow, moveCount, cursorRow + count);

  for (var i = count - 1; i >= 0; i--) {
    this.setAbsoluteCursorPosition(cursorRow + i, 0);
    this.screen_.clearCursorRow();
  }
};

/**
 * VT command to delete lines at the current cursor row.
 *
 * New rows are added to the bottom of scroll region to take their place.  New
 * rows are strictly there to take up space and have no content or style.
 *
 * @param {number} count The number of lines to delete.
 */
hterm.Terminal.prototype.deleteLines = function(count) {
  var cursor = this.saveCursor();

  var top = cursor.row;
  var bottom = this.getVTScrollBottom();

  var maxCount = bottom - top + 1;
  count = Math.min(count, maxCount);

  var moveStart = bottom - count + 1;
  if (count != maxCount)
    this.moveRows_(top, count, moveStart);

  for (var i = 0; i < count; i++) {
    this.setAbsoluteCursorPosition(moveStart + i, 0);
    this.screen_.clearCursorRow();
  }

  this.restoreCursor(cursor);
  this.clearCursorOverflow();
};

/**
 * Inserts the given number of spaces at the current cursor position.
 *
 * The cursor position is not changed.
 *
 * @param {number} count The number of spaces to insert.
 */
hterm.Terminal.prototype.insertSpace = function(count) {
  var cursor = this.saveCursor();

  var ws = lib.f.getWhitespace(count || 1);
  this.screen_.insertString(ws, ws.length);
  this.screen_.maybeClipCurrentRow();

  this.restoreCursor(cursor);
  this.clearCursorOverflow();
};

/**
 * Forward-delete the specified number of characters starting at the cursor
 * position.
 *
 * @param {integer} count The number of characters to delete.
 */
hterm.Terminal.prototype.deleteChars = function(count) {
  var deleted = this.screen_.deleteChars(count);
  if (deleted && !this.screen_.textAttributes.isDefault()) {
    var cursor = this.saveCursor();
    this.setCursorColumn(this.screenSize.width - deleted);
    this.screen_.insertString(lib.f.getWhitespace(deleted));
    this.restoreCursor(cursor);
  }

  this.clearCursorOverflow();
};

/**
 * Shift rows in the scroll region upwards by a given number of lines.
 *
 * New rows are inserted at the bottom of the scroll region to fill the
 * vacated rows.  The new rows not filled out with the current text attributes.
 *
 * This function does not affect the scrollback rows at all.  Rows shifted
 * off the top are lost.
 *
 * The cursor position is not altered.
 *
 * @param {integer} count The number of rows to scroll.
 */
hterm.Terminal.prototype.vtScrollUp = function(count) {
  var cursor = this.saveCursor();

  this.setAbsoluteCursorRow(this.getVTScrollTop());
  this.deleteLines(count);

  this.restoreCursor(cursor);
};

/**
 * Shift rows below the cursor down by a given number of lines.
 *
 * This function respects the current scroll region.
 *
 * New rows are inserted at the top of the scroll region to fill the
 * vacated rows.  The new rows not filled out with the current text attributes.
 *
 * This function does not affect the scrollback rows at all.  Rows shifted
 * off the bottom are lost.
 *
 * @param {integer} count The number of rows to scroll.
 */
hterm.Terminal.prototype.vtScrollDown = function(opt_count) {
  var cursor = this.saveCursor();

  this.setAbsoluteCursorPosition(this.getVTScrollTop(), 0);
  this.insertLines(opt_count);

  this.restoreCursor(cursor);
};

/**
 * Enable accessibility-friendly features that have a performance impact.
 *
 * This will generate additional DOM nodes in an aria-live region that will
 * cause Assitive Technology to announce the output of the terminal. It also
 * enables other features that aid assistive technology. All the features gated
 * behind this flag have a performance impact on the terminal which is why they
 * are made optional.
 *
 * @param {boolean} enabled Whether to enable accessibility-friendly features.
 */
hterm.Terminal.prototype.setAccessibilityEnabled = function(enabled) {
  this.accessibilityReader_.setAccessibilityEnabled(enabled);
};

/**
 * Set the cursor position.
 *
 * The cursor row is relative to the scroll region if the terminal has
 * 'origin mode' enabled, or relative to the addressable screen otherwise.
 *
 * @param {integer} row The new zero-based cursor row.
 * @param {integer} row The new zero-based cursor column.
 */
hterm.Terminal.prototype.setCursorPosition = function(row, column) {
  if (this.options_.originMode) {
    this.setRelativeCursorPosition(row, column);
  } else {
    this.setAbsoluteCursorPosition(row, column);
  }
};

/**
 * Move the cursor relative to its current position.
 *
 * @param {number} row
 * @param {number} column
 */
hterm.Terminal.prototype.setRelativeCursorPosition = function(row, column) {
  var scrollTop = this.getVTScrollTop();
  row = lib.f.clamp(row + scrollTop, scrollTop, this.getVTScrollBottom());
  column = lib.f.clamp(column, 0, this.screenSize.width - 1);
  this.screen_.setCursorPosition(row, column);
};

/**
 * Move the cursor to the specified position.
 *
 * @param {number} row
 * @param {number} column
 */
hterm.Terminal.prototype.setAbsoluteCursorPosition = function(row, column) {
  row = lib.f.clamp(row, 0, this.screenSize.height - 1);
  column = lib.f.clamp(column, 0, this.screenSize.width - 1);
  this.screen_.setCursorPosition(row, column);
};

/**
 * Set the cursor column.
 *
 * @param {integer} column The new zero-based cursor column.
 */
hterm.Terminal.prototype.setCursorColumn = function(column) {
  this.setAbsoluteCursorPosition(this.screen_.cursorPosition.row, column);
};

/**
 * Return the cursor column.
 *
 * @return {integer} The zero-based cursor column.
 */
hterm.Terminal.prototype.getCursorColumn = function() {
  return this.screen_.cursorPosition.column;
};

/**
 * Set the cursor row.
 *
 * The cursor row is relative to the scroll region if the terminal has
 * 'origin mode' enabled, or relative to the addressable screen otherwise.
 *
 * @param {integer} row The new cursor row.
 */
hterm.Terminal.prototype.setAbsoluteCursorRow = function(row) {
  this.setAbsoluteCursorPosition(row, this.screen_.cursorPosition.column);
};

/**
 * Return the cursor row.
 *
 * @return {integer} The zero-based cursor row.
 */
hterm.Terminal.prototype.getCursorRow = function() {
  return this.screen_.cursorPosition.row;
};

/**
 * Request that the ScrollPort redraw itself soon.
 *
 * The redraw will happen asynchronously, soon after the call stack winds down.
 * Multiple calls will be coalesced into a single redraw.
 */
hterm.Terminal.prototype.scheduleRedraw_ = function() {
  if (this.timeouts_.redraw)
    return;

  var self = this;
  this.timeouts_.redraw = setTimeout(function() {
      delete self.timeouts_.redraw;
      self.scrollPort_.redraw_();
    }, 0);
};

/**
 * Request that the ScrollPort be scrolled to the bottom.
 *
 * The scroll will happen asynchronously, soon after the call stack winds down.
 * Multiple calls will be coalesced into a single scroll.
 *
 * This affects the scrollbar position of the ScrollPort, and has nothing to
 * do with the VT scroll commands.
 */
hterm.Terminal.prototype.scheduleScrollDown_ = function() {
  if (this.timeouts_.scrollDown)
    return;

  var self = this;
  this.timeouts_.scrollDown = setTimeout(function() {
      delete self.timeouts_.scrollDown;
      self.scrollPort_.scrollRowToBottom(self.getRowCount());
    }, 10);
};

/**
 * Move the cursor up a specified number of rows.
 *
 * @param {integer} count The number of rows to move the cursor.
 */
hterm.Terminal.prototype.cursorUp = function(count) {
  return this.cursorDown(-(count || 1));
};

/**
 * Move the cursor down a specified number of rows.
 *
 * @param {integer} count The number of rows to move the cursor.
 */
hterm.Terminal.prototype.cursorDown = function(count) {
  count = count || 1;
  var minHeight = (this.options_.originMode ? this.getVTScrollTop() : 0);
  var maxHeight = (this.options_.originMode ? this.getVTScrollBottom() :
                   this.screenSize.height - 1);

  var row = lib.f.clamp(this.screen_.cursorPosition.row + count,
                        minHeight, maxHeight);
  this.setAbsoluteCursorRow(row);
};

/**
 * Move the cursor left a specified number of columns.
 *
 * If reverse wraparound mode is enabled and the previous row wrapped into
 * the current row then we back up through the wraparound as well.
 *
 * @param {integer} count The number of columns to move the cursor.
 */
hterm.Terminal.prototype.cursorLeft = function(count) {
  count = count || 1;

  if (count < 1)
    return;

  var currentColumn = this.screen_.cursorPosition.column;
  if (this.options_.reverseWraparound) {
    if (this.screen_.cursorPosition.overflow) {
      // If this cursor is in the right margin, consume one count to get it
      // back to the last column.  This only applies when we're in reverse
      // wraparound mode.
      count--;
      this.clearCursorOverflow();

      if (!count)
        return;
    }

    var newRow = this.screen_.cursorPosition.row;
    var newColumn = currentColumn - count;
    if (newColumn < 0) {
      newRow = newRow - Math.floor(count / this.screenSize.width) - 1;
      if (newRow < 0) {
        // xterm also wraps from row 0 to the last row.
        newRow = this.screenSize.height + newRow % this.screenSize.height;
      }
      newColumn = this.screenSize.width + newColumn % this.screenSize.width;
    }

    this.setCursorPosition(Math.max(newRow, 0), newColumn);

  } else {
    var newColumn = Math.max(currentColumn - count, 0);
    this.setCursorColumn(newColumn);
  }
};

/**
 * Move the cursor right a specified number of columns.
 *
 * @param {integer} count The number of columns to move the cursor.
 */
hterm.Terminal.prototype.cursorRight = function(count) {
  count = count || 1;

  if (count < 1)
    return;

  var column = lib.f.clamp(this.screen_.cursorPosition.column + count,
                           0, this.screenSize.width - 1);
  this.setCursorColumn(column);
};

/**
 * Reverse the foreground and background colors of the terminal.
 *
 * This only affects text that was drawn with no attributes.
 *
 * TODO(rginda): Test xterm to see if reverse is respected for text that has
 * been drawn with attributes that happen to coincide with the default
 * 'no-attribute' colors.  My guess is probably not.
 *
 * @param {boolean} state The state to set.
 */
hterm.Terminal.prototype.setReverseVideo = function(state) {
  this.options_.reverseVideo = state;
  if (state) {
    this.scrollPort_.setForegroundColor(this.prefs_.get('background-color'));
    this.scrollPort_.setBackgroundColor(this.prefs_.get('foreground-color'));
  } else {
    this.scrollPort_.setForegroundColor(this.prefs_.get('foreground-color'));
    this.scrollPort_.setBackgroundColor(this.prefs_.get('background-color'));
  }
};

/**
 * Ring the terminal bell.
 *
 * This will not play the bell audio more than once per second.
 */
hterm.Terminal.prototype.ringBell = function() {
  this.cursorNode_.style.backgroundColor =
      this.scrollPort_.getForegroundColor();

  var self = this;
  setTimeout(function() {
      self.restyleCursor_();
    }, 200);

  // bellSquelchTimeout_ affects both audio and notification bells.
  if (this.bellSquelchTimeout_)
    return;

  if (this.bellAudio_.getAttribute('src')) {
    this.bellAudio_.play();
    this.bellSequelchTimeout_ = setTimeout(function() {
        delete this.bellSquelchTimeout_;
      }.bind(this), 500);
  } else {
    delete this.bellSquelchTimeout_;
  }

  if (this.desktopNotificationBell_ && !this.document_.hasFocus()) {
    var n = hterm.notify();
    this.bellNotificationList_.push(n);
    // TODO: Should we try to raise the window here?
    n.onclick = function() { self.closeBellNotifications_(); };
  }
};

/**
 * Set the origin mode bit.
 *
 * If origin mode is on, certain VT cursor and scrolling commands measure their
 * row parameter relative to the VT scroll region.  Otherwise, row 0 corresponds
 * to the top of the addressable screen.
 *
 * Defaults to off.
 *
 * @param {boolean} state True to set origin mode, false to unset.
 */
hterm.Terminal.prototype.setOriginMode = function(state) {
  this.options_.originMode = state;
  this.setCursorPosition(0, 0);
};

/**
 * Set the insert mode bit.
 *
 * If insert mode is on, existing text beyond the cursor position will be
 * shifted right to make room for new text.  Otherwise, new text overwrites
 * any existing text.
 *
 * Defaults to off.
 *
 * @param {boolean} state True to set insert mode, false to unset.
 */
hterm.Terminal.prototype.setInsertMode = function(state) {
  this.options_.insertMode = state;
};

/**
 * Set the auto carriage return bit.
 *
 * If auto carriage return is on then a formfeed character is interpreted
 * as a newline, otherwise it's the same as a linefeed.  The difference boils
 * down to whether or not the cursor column is reset.
 *
 * @param {boolean} state The state to set.
 */
hterm.Terminal.prototype.setAutoCarriageReturn = function(state) {
  this.options_.autoCarriageReturn = state;
};

/**
 * Set the wraparound mode bit.
 *
 * If wraparound mode is on, certain VT commands will allow the cursor to wrap
 * to the start of the following row.  Otherwise, the cursor is clamped to the
 * end of the screen and attempts to write past it are ignored.
 *
 * Defaults to on.
 *
 * @param {boolean} state True to set wraparound mode, false to unset.
 */
hterm.Terminal.prototype.setWraparound = function(state) {
  this.options_.wraparound = state;
};

/**
 * Set the reverse-wraparound mode bit.
 *
 * If wraparound mode is off, certain VT commands will allow the cursor to wrap
 * to the end of the previous row.  Otherwise, the cursor is clamped to column
 * 0.
 *
 * Defaults to off.
 *
 * @param {boolean} state True to set reverse-wraparound mode, false to unset.
 */
hterm.Terminal.prototype.setReverseWraparound = function(state) {
  this.options_.reverseWraparound = state;
};

/**
 * Selects between the primary and alternate screens.
 *
 * If alternate mode is on, the alternate screen is active.  Otherwise the
 * primary screen is active.
 *
 * Swapping screens has no effect on the scrollback buffer.
 *
 * Each screen maintains its own cursor position.
 *
 * Defaults to off.
 *
 * @param {boolean} state True to set alternate mode, false to unset.
 */
hterm.Terminal.prototype.setAlternateMode = function(state) {
  var cursor = this.saveCursor();
  this.screen_ = state ? this.alternateScreen_ : this.primaryScreen_;

  if (this.screen_.rowsArray.length &&
      this.screen_.rowsArray[0].rowIndex != this.scrollbackRows_.length) {
    // If the screen changed sizes while we were away, our rowIndexes may
    // be incorrect.
    var offset = this.scrollbackRows_.length;
    var ary = this.screen_.rowsArray;
    for (var i = 0; i < ary.length; i++) {
      ary[i].rowIndex = offset + i;
    }
  }

  this.realizeWidth_(this.screenSize.width);
  this.realizeHeight_(this.screenSize.height);
  this.scrollPort_.syncScrollHeight();
  this.scrollPort_.invalidate();

  this.restoreCursor(cursor);
  this.scrollPort_.resize();
};

/**
 * Set the cursor-blink mode bit.
 *
 * If cursor-blink is on, the cursor will blink when it is visible.  Otherwise
 * a visible cursor does not blink.
 *
 * You should make sure to turn blinking off if you're going to dispose of a
 * terminal, otherwise you'll leak a timeout.
 *
 * Defaults to on.
 *
 * @param {boolean} state True to set cursor-blink mode, false to unset.
 */
hterm.Terminal.prototype.setCursorBlink = function(state) {
  this.options_.cursorBlink = state;

  if (!state && this.timeouts_.cursorBlink) {
    clearTimeout(this.timeouts_.cursorBlink);
    delete this.timeouts_.cursorBlink;
  }

  if (this.options_.cursorVisible)
    this.setCursorVisible(true);
};

/**
 * Set the cursor-visible mode bit.
 *
 * If cursor-visible is on, the cursor will be visible.  Otherwise it will not.
 *
 * Defaults to on.
 *
 * @param {boolean} state True to set cursor-visible mode, false to unset.
 */
hterm.Terminal.prototype.setCursorVisible = function(state) {
  this.options_.cursorVisible = state;

  if (!state) {
    if (this.timeouts_.cursorBlink) {
      clearTimeout(this.timeouts_.cursorBlink);
      delete this.timeouts_.cursorBlink;
    }
    this.cursorNode_.style.opacity = '0';
    return;
  }

  this.syncCursorPosition_();

  this.cursorNode_.style.opacity = '1';

  if (this.options_.cursorBlink) {
    if (this.timeouts_.cursorBlink)
      return;

    this.onCursorBlink_();
  } else {
    if (this.timeouts_.cursorBlink) {
      clearTimeout(this.timeouts_.cursorBlink);
      delete this.timeouts_.cursorBlink;
    }
  }
};

/**
 * Synchronizes the visible cursor and document selection with the current
 * cursor coordinates.
 *
 * @return {boolean} True if the cursor is onscreen and synced.
 */
hterm.Terminal.prototype.syncCursorPosition_ = function() {
  var topRowIndex = this.scrollPort_.getTopRowIndex();
  var bottomRowIndex = this.scrollPort_.getBottomRowIndex(topRowIndex);
  var cursorRowIndex = this.scrollbackRows_.length +
      this.screen_.cursorPosition.row;

  let forceSyncSelection = false;
  if (this.accessibilityReader_.accessibilityEnabled) {
    // Report the new position of the cursor for accessibility purposes.
    const cursorColumnIndex = this.screen_.cursorPosition.column;
    const cursorLineText =
        this.screen_.rowsArray[this.screen_.cursorPosition.row].innerText;
    // This will force the selection to be sync'd to the cursor position if the
    // user has pressed a key. Generally we would only sync the cursor position
    // when selection is collapsed so that if the user has selected something
    // we don't clear the selection by moving the selection. However when a
    // screen reader is used, it's intuitive for entering a key to move the
    // selection to the cursor.
    forceSyncSelection = this.accessibilityReader_.hasUserGesture;
    this.accessibilityReader_.afterCursorChange(
        cursorLineText, cursorRowIndex, cursorColumnIndex);
  }

  if (cursorRowIndex > bottomRowIndex) {
    // Cursor is scrolled off screen, move it outside of the visible area.
    this.setCssVar('cursor-offset-row', '-1');
    return false;
  }

  if (this.options_.cursorVisible &&
      this.cursorNode_.style.display == 'none') {
    // Re-display the terminal cursor if it was hidden by the mouse cursor.
    this.cursorNode_.style.display = '';
  }

  // Position the cursor using CSS variable math.  If we do the math in JS,
  // the float math will end up being more precise than the CSS which will
  // cause the cursor tracking to be off.
  this.setCssVar(
      'cursor-offset-row',
      `${cursorRowIndex - topRowIndex} + ` +
      `${this.scrollPort_.visibleRowTopMargin}px`);
  this.setCssVar('cursor-offset-col', this.screen_.cursorPosition.column);

  this.cursorNode_.setAttribute('title',
                                '(' + this.screen_.cursorPosition.column +
                                ', ' + this.screen_.cursorPosition.row +
                                ')');

  // Update the caret for a11y purposes.
  var selection = this.document_.getSelection();
  if (selection && (selection.isCollapsed || forceSyncSelection)) {
    this.screen_.syncSelectionCaret(selection);
  }
  return true;
};

/**
 * Adjusts the style of this.cursorNode_ according to the current cursor shape
 * and character cell dimensions.
 */
hterm.Terminal.prototype.restyleCursor_ = function() {
  var shape = this.cursorShape_;

  if (this.cursorNode_.getAttribute('focus') == 'false') {
    // Always show a block cursor when unfocused.
    shape = hterm.Terminal.cursorShape.BLOCK;
  }

  var style = this.cursorNode_.style;

  switch (shape) {
    case hterm.Terminal.cursorShape.BEAM:
      style.height = 'var(--hterm-charsize-height)';
      style.backgroundColor = 'transparent';
      style.borderBottomStyle = null;
      style.borderLeftStyle = 'solid';
      break;

    case hterm.Terminal.cursorShape.UNDERLINE:
      style.height = this.scrollPort_.characterSize.baseline + 'px';
      style.backgroundColor = 'transparent';
      style.borderBottomStyle = 'solid';
      // correct the size to put it exactly at the baseline
      style.borderLeftStyle = null;
      break;

    default:
      style.height = 'var(--hterm-charsize-height)';
      style.backgroundColor = 'var(--hterm-cursor-color)';
      style.borderBottomStyle = null;
      style.borderLeftStyle = null;
      break;
  }
};

/**
 * Synchronizes the visible cursor with the current cursor coordinates.
 *
 * The sync will happen asynchronously, soon after the call stack winds down.
 * Multiple calls will be coalesced into a single sync. This should be called
 * prior to the cursor actually changing position.
 */
hterm.Terminal.prototype.scheduleSyncCursorPosition_ = function() {
  if (this.timeouts_.syncCursor)
    return;

  if (this.accessibilityReader_.accessibilityEnabled) {
    // Report the previous position of the cursor for accessibility purposes.
    const cursorRowIndex = this.scrollbackRows_.length +
        this.screen_.cursorPosition.row;
    const cursorColumnIndex = this.screen_.cursorPosition.column;
    const cursorLineText =
        this.screen_.rowsArray[this.screen_.cursorPosition.row].innerText;
    this.accessibilityReader_.beforeCursorChange(
        cursorLineText, cursorRowIndex, cursorColumnIndex);
  }

  var self = this;
  this.timeouts_.syncCursor = setTimeout(function() {
      self.syncCursorPosition_();
      delete self.timeouts_.syncCursor;
    }, 0);
};

/**
 * Show or hide the zoom warning.
 *
 * The zoom warning is a message warning the user that their browser zoom must
 * be set to 100% in order for hterm to function properly.
 *
 * @param {boolean} state True to show the message, false to hide it.
 */
hterm.Terminal.prototype.showZoomWarning_ = function(state) {
  if (!this.zoomWarningNode_) {
    if (!state)
      return;

    this.zoomWarningNode_ = this.document_.createElement('div');
    this.zoomWarningNode_.id = 'hterm:zoom-warning';
    this.zoomWarningNode_.style.cssText = (
        'color: black;' +
        'background-color: #ff2222;' +
        'font-size: large;' +
        'border-radius: 8px;' +
        'opacity: 0.75;' +
        'padding: 0.2em 0.5em 0.2em 0.5em;' +
        'top: 0.5em;' +
        'right: 1.2em;' +
        'position: absolute;' +
        '-webkit-text-size-adjust: none;' +
        '-webkit-user-select: none;' +
        '-moz-text-size-adjust: none;' +
        '-moz-user-select: none;');

    this.zoomWarningNode_.addEventListener('click', function(e) {
      this.parentNode.removeChild(this);
    });
  }

  this.zoomWarningNode_.textContent = lib.MessageManager.replaceReferences(
      hterm.zoomWarningMessage,
      [parseInt(this.scrollPort_.characterSize.zoomFactor * 100)]);

  this.zoomWarningNode_.style.fontFamily = this.prefs_.get('font-family');

  if (state) {
    if (!this.zoomWarningNode_.parentNode)
      this.div_.parentNode.appendChild(this.zoomWarningNode_);
  } else if (this.zoomWarningNode_.parentNode) {
    this.zoomWarningNode_.parentNode.removeChild(this.zoomWarningNode_);
  }
};

/**
 * Show the terminal overlay for a given amount of time.
 *
 * The terminal overlay appears in inverse video in a large font, centered
 * over the terminal.  You should probably keep the overlay message brief,
 * since it's in a large font and you probably aren't going to check the size
 * of the terminal first.
 *
 * @param {string} msg The text (not HTML) message to display in the overlay.
 * @param {number} opt_timeout The amount of time to wait before fading out
 *     the overlay.  Defaults to 1.5 seconds.  Pass null to have the overlay
 *     stay up forever (or until the next overlay).
 */
hterm.Terminal.prototype.showOverlay = function(msg, opt_timeout) {
  if (!this.overlayNode_) {
    if (!this.div_)
      return;

    this.overlayNode_ = this.document_.createElement('div');
    this.overlayNode_.style.cssText = (
        'border-radius: 15px;' +
        'font-size: xx-large;' +
        'opacity: 0.75;' +
        'padding: 0.2em 0.5em 0.2em 0.5em;' +
        'position: absolute;' +
        '-webkit-user-select: none;' +
        '-webkit-transition: opacity 180ms ease-in;' +
        '-moz-user-select: none;' +
        '-moz-transition: opacity 180ms ease-in;');

    this.overlayNode_.addEventListener('mousedown', function(e) {
      e.preventDefault();
      e.stopPropagation();
    }, true);
  }

  this.overlayNode_.style.color = this.prefs_.get('background-color');
  this.overlayNode_.style.backgroundColor = this.prefs_.get('foreground-color');
  this.overlayNode_.style.fontFamily = this.prefs_.get('font-family');

  this.overlayNode_.textContent = msg;
  this.overlayNode_.style.opacity = '0.75';

  if (!this.overlayNode_.parentNode)
    this.div_.appendChild(this.overlayNode_);

  var divSize = hterm.getClientSize(this.div_);
  var overlaySize = hterm.getClientSize(this.overlayNode_);

  this.overlayNode_.style.top =
      (divSize.height - overlaySize.height) / 2 + 'px';
  this.overlayNode_.style.left = (divSize.width - overlaySize.width -
      this.scrollPort_.currentScrollbarWidthPx) / 2 + 'px';

  if (this.overlayTimeout_)
    clearTimeout(this.overlayTimeout_);

  this.accessibilityReader_.assertiveAnnounce(msg);

  if (opt_timeout === null)
    return;

  this.overlayTimeout_ = setTimeout(() => {
    this.overlayNode_.style.opacity = '0';
    this.overlayTimeout_ = setTimeout(() => this.hideOverlay(), 200);
  }, opt_timeout || 1500);
};

/**
 * Hide the terminal overlay immediately.
 *
 * Useful when we show an overlay for an event with an unknown end time.
 */
hterm.Terminal.prototype.hideOverlay = function() {
  if (this.overlayTimeout_)
    clearTimeout(this.overlayTimeout_);
  this.overlayTimeout_ = null;

  if (this.overlayNode_.parentNode)
    this.overlayNode_.parentNode.removeChild(this.overlayNode_);
  this.overlayNode_.style.opacity = '0.75';
};

/**
 * Paste from the system clipboard to the terminal.
 */
hterm.Terminal.prototype.paste = function() {
  return hterm.pasteFromClipboard(this.document_);
};

/**
 * Copy a string to the system clipboard.
 *
 * Note: If there is a selected range in the terminal, it'll be cleared.
 *
 * @param {string} str The string to copy.
 */
hterm.Terminal.prototype.copyStringToClipboard = function(str) {
  if (this.prefs_.get('enable-clipboard-notice'))
    setTimeout(this.showOverlay.bind(this, hterm.notifyCopyMessage, 500), 200);

  hterm.copySelectionToClipboard(this.document_, str);
};

/**
 * Display an image.
 *
 * @param {Object} options The image to display.
 * @param {string=} options.name A human readable string for the image.
 * @param {string|number=} options.size The size (in bytes).
 * @param {boolean=} options.preserveAspectRatio Whether to preserve aspect.
 * @param {boolean=} options.inline Whether to display the image inline.
 * @param {string|number=} options.width The width of the image.
 * @param {string|number=} options.height The height of the image.
 * @param {string=} options.align Direction to align the image.
 * @param {string} options.uri The source URI for the image.
 * @param {function=} onLoad Callback when loading finishes.
 * @param {function(Event)=} onError Callback when loading fails.
 */
hterm.Terminal.prototype.displayImage = function(options, onLoad, onError) {
  // Make sure we're actually given a resource to display.
  if (options.uri === undefined)
    return;

  // Set up the defaults to simplify code below.
  if (!options.name)
    options.name = '';

  // Has the user approved image display yet?
  if (this.allowImagesInline !== true) {
    this.newLine();
    const row = this.getRowNode(this.scrollbackRows_.length +
                                this.getCursorRow() - 1);

    if (this.allowImagesInline === false) {
      row.textContent = hterm.msg('POPUP_INLINE_IMAGE_DISABLED', [],
                                  'Inline Images Disabled');
      return;
    }

    // Show a prompt.
    let button;
    const span = this.document_.createElement('span');
    span.innerText = hterm.msg('POPUP_INLINE_IMAGE', [], 'Inline Images');
    span.style.fontWeight = 'bold';
    span.style.borderWidth = '1px';
    span.style.borderStyle = 'dashed';
    button = this.document_.createElement('span');
    button.innerText = hterm.msg('BUTTON_BLOCK', [], 'block');
    button.style.marginLeft = '1em';
    button.style.borderWidth = '1px';
    button.style.borderStyle = 'solid';
    button.addEventListener('click', () => {
      this.prefs_.set('allow-images-inline', false);
    });
    span.appendChild(button);
    button = this.document_.createElement('span');
    button.innerText = hterm.msg('BUTTON_ALLOW_SESSION', [],
                                 'allow this session');
    button.style.marginLeft = '1em';
    button.style.borderWidth = '1px';
    button.style.borderStyle = 'solid';
    button.addEventListener('click', () => {
      this.allowImagesInline = true;
    });
    span.appendChild(button);
    button = this.document_.createElement('span');
    button.innerText = hterm.msg('BUTTON_ALLOW_ALWAYS', [], 'always allow');
    button.style.marginLeft = '1em';
    button.style.borderWidth = '1px';
    button.style.borderStyle = 'solid';
    button.addEventListener('click', () => {
      this.prefs_.set('allow-images-inline', true);
    });
    span.appendChild(button);

    row.appendChild(span);
    return;
  }

  // See if we should show this object directly, or download it.
  if (options.inline) {
    const io = this.io.push();
    io.showOverlay(hterm.msg('LOADING_RESOURCE_START', [options.name],
                             'Loading $1 ...'), null);

    // While we're loading the image, eat all the user's input.
    io.onVTKeystroke = io.sendString = () => {};

    // Initialize this new image.
    const img =
        /** @type {!HTMLImageElement} */ (this.document_.createElement('img'));
    img.src = options.uri;
    img.title = img.alt = options.name;

    // Attach the image to the page to let it load/render.  It won't stay here.
    // This is needed so it's visible and the DOM can calculate the height.  If
    // the image is hidden or not in the DOM, the height is always 0.
    this.document_.body.appendChild(img);

    // Wait for the image to finish loading before we try moving it to the
    // right place in the terminal.
    img.onload = () => {
      // Now that we have the image dimensions, figure out how to show it.
      img.style.objectFit = options.preserveAspectRatio ? 'scale-down' : 'fill';
      img.style.maxWidth = `${this.document_.body.clientWidth}px`;
      img.style.maxHeight = `${this.document_.body.clientHeight}px`;

      // Parse a width/height specification.
      const parseDim = (dim, maxDim, cssVar) => {
        if (!dim || dim == 'auto')
          return '';

        const ary = dim.match(/^([0-9]+)(px|%)?$/);
        if (ary) {
          if (ary[2] == '%')
            return maxDim * parseInt(ary[1]) / 100 + 'px';
          else if (ary[2] == 'px')
            return dim;
          else
            return `calc(${dim} * var(${cssVar}))`;
        }

        return '';
      };
      img.style.width =
          parseDim(options.width, this.document_.body.clientWidth,
                   '--hterm-charsize-width');
      img.style.height =
          parseDim(options.height,  this.document_.body.clientHeight,
                   '--hterm-charsize-height');

      // Figure out how many rows the image occupies, then add that many.
      // XXX: This count will be inaccurate if the font size changes on us.
      const padRows = Math.ceil(img.clientHeight /
                                this.scrollPort_.characterSize.height);
      for (let i = 0; i < padRows; ++i)
        this.newLine();

      // Update the max height in case the user shrinks the character size.
      img.style.maxHeight = `calc(${padRows} * var(--hterm-charsize-height))`;

      // Move the image to the last row.  This way when we scroll up, it doesn't
      // disappear when the first row gets clipped.  It will disappear when we
      // scroll down and the last row is clipped ...
      this.document_.body.removeChild(img);
      // Create a wrapper node so we can do an absolute in a relative position.
      // This helps with rounding errors between JS & CSS counts.
      const div = this.document_.createElement('div');
      div.style.position = 'relative';
      div.style.textAlign = options.align;
      img.style.position = 'absolute';
      img.style.bottom = 'calc(0px - var(--hterm-charsize-height))';
      div.appendChild(img);
      const row = this.getRowNode(this.scrollbackRows_.length +
                                  this.getCursorRow() - 1);
      row.appendChild(div);

      io.hideOverlay();
      io.pop();

      if (onLoad)
        onLoad();
    };

    // If we got a malformed image, give up.
    img.onerror = (e) => {
      this.document_.body.removeChild(img);
      io.showOverlay(hterm.msg('LOADING_RESOURCE_FAILED', [options.name],
                               'Loading $1 failed'));
      io.pop();

      if (onError)
        onError(e);
    };
  } else {
    // We can't use chrome.downloads.download as that requires "downloads"
    // permissions, and that works only in extensions, not apps.
    const a = this.document_.createElement('a');
    a.href = options.uri;
    a.download = options.name;
    this.document_.body.appendChild(a);
    a.click();
    a.remove();
  }
};

/**
 * Returns the selected text, or null if no text is selected.
 *
 * @return {string|null}
 */
hterm.Terminal.prototype.getSelectionText = function() {
  var selection = this.scrollPort_.selection;
  selection.sync();

  if (selection.isCollapsed)
    return null;

  // Start offset measures from the beginning of the line.
  var startOffset = selection.startOffset;
  var node = selection.startNode;

  // If an x-row isn't selected, |node| will be null.
  if (!node)
    return null;

  if (node.nodeName != 'X-ROW') {
    // If the selection doesn't start on an x-row node, then it must be
    // somewhere inside the x-row.  Add any characters from previous siblings
    // into the start offset.

    if (node.nodeName == '#text' && node.parentNode.nodeName == 'SPAN') {
      // If node is the text node in a styled span, move up to the span node.
      node = node.parentNode;
    }

    while (node.previousSibling) {
      node = node.previousSibling;
      startOffset += hterm.TextAttributes.nodeWidth(node);
    }
  }

  // End offset measures from the end of the line.
  var endOffset = (hterm.TextAttributes.nodeWidth(selection.endNode) -
                   selection.endOffset);
  node = selection.endNode;

  if (node.nodeName != 'X-ROW') {
    // If the selection doesn't end on an x-row node, then it must be
    // somewhere inside the x-row.  Add any characters from following siblings
    // into the end offset.

    if (node.nodeName == '#text' && node.parentNode.nodeName == 'SPAN') {
      // If node is the text node in a styled span, move up to the span node.
      node = node.parentNode;
    }

    while (node.nextSibling) {
      node = node.nextSibling;
      endOffset += hterm.TextAttributes.nodeWidth(node);
    }
  }

  var rv = this.getRowsText(selection.startRow.rowIndex,
                            selection.endRow.rowIndex + 1);
  return lib.wc.substring(rv, startOffset, lib.wc.strWidth(rv) - endOffset);
};

/**
 * Copy the current selection to the system clipboard, then clear it after a
 * short delay.
 */
hterm.Terminal.prototype.copySelectionToClipboard = function() {
  var text = this.getSelectionText();
  if (text != null)
    this.copyStringToClipboard(text);
};

hterm.Terminal.prototype.overlaySize = function() {
  this.showOverlay(this.screenSize.width + 'x' + this.screenSize.height);
};

/**
 * Invoked by hterm.Terminal.Keyboard when a VT keystroke is detected.
 *
 * @param {string} string The VT string representing the keystroke, in UTF-16.
 */
hterm.Terminal.prototype.onVTKeystroke = function(string) {
  if (this.scrollOnKeystroke_)
    this.scrollPort_.scrollRowToBottom(this.getRowCount());

  this.io.onVTKeystroke(string);
};

/**
 * Open the selected url.
 */
hterm.Terminal.prototype.openSelectedUrl_ = function() {
  var str = this.getSelectionText();

  // If there is no selection, try and expand wherever they clicked.
  if (str == null) {
    this.screen_.expandSelectionForUrl(this.document_.getSelection());
    str = this.getSelectionText();

    // If clicking in empty space, return.
    if (str == null)
      return;
  }

  // Make sure URL is valid before opening.
  if (str.length > 2048 || str.search(/[\s\[\](){}<>"'\\^`]/) >= 0)
    return;

  // If the URI isn't anchored, it'll open relative to the extension.
  // We have no way of knowing the correct schema, so assume http.
  if (str.search('^[a-zA-Z][a-zA-Z0-9+.-]*://') < 0) {
    // We have to whitelist a few protocols that lack authorities and thus
    // never use the //.  Like mailto.
    switch (str.split(':', 1)[0]) {
      case 'mailto':
        break;
      default:
        str = 'http://' + str;
        break;
    }
  }

  hterm.openUrl(str);
};

/**
 * Manage the automatic mouse hiding behavior while typing.
 *
 * @param {boolean=} v Whether to enable automatic hiding.
 */
hterm.Terminal.prototype.setAutomaticMouseHiding = function(v=null) {
  // Since Chrome OS & macOS do this by default everywhere, we don't need to.
  // Linux & Windows seem to leave this to specific applications to manage.
  if (v === null)
    v = (hterm.os != 'cros' && hterm.os != 'mac');

  this.mouseHideWhileTyping_ = !!v;
};

/**
 * Handler for monitoring user keyboard activity.
 *
 * This isn't for processing the keystrokes directly, but for updating any
 * state that might toggle based on the user using the keyboard at all.
 *
 * @param {KeyboardEvent} e The keyboard event that triggered us.
 */
hterm.Terminal.prototype.onKeyboardActivity_ = function(e) {
  // When the user starts typing, hide the mouse cursor.
  if (this.mouseHideWhileTyping_ && !this.mouseHideDelay_)
    this.setCssVar('mouse-cursor-style', 'none');
};

/**
 * Add the terminalRow and terminalColumn properties to mouse events and
 * then forward on to onMouse().
 *
 * The terminalRow and terminalColumn properties contain the (row, column)
 * coordinates for the mouse event.
 *
 * @param {Event} e The mouse event to handle.
 */
hterm.Terminal.prototype.onMouse_ = function(e) {
  if (e.processedByTerminalHandler_) {
    // We register our event handlers on the document, as well as the cursor
    // and the scroll blocker.  Mouse events that occur on the cursor or
    // scroll blocker will also appear on the document, but we don't want to
    // process them twice.
    //
    // We can't just prevent bubbling because that has other side effects, so
    // we decorate the event object with this property instead.
    return;
  }

  // Consume navigation events.  Button 3 is usually "browser back" and
  // button 4 is "browser forward" which we don't want to happen.
  if (e.button > 2) {
    e.preventDefault();
    // We don't return so click events can be passed to the remote below.
  }

  var reportMouseEvents = (!this.defeatMouseReports_ &&
      this.vt.mouseReport != this.vt.MOUSE_REPORT_DISABLED);

  e.processedByTerminalHandler_ = true;

  // Handle auto hiding of mouse cursor while typing.
  if (this.mouseHideWhileTyping_ && !this.mouseHideDelay_) {
    // Make sure the mouse cursor is visible.
    this.syncMouseStyle();
    // This debounce isn't perfect, but should work well enough for such a
    // simple implementation.  If the user moved the mouse, we enabled this
    // debounce, and then moved the mouse just before the timeout, we wouldn't
    // debounce that later movement.
    this.mouseHideDelay_ = setTimeout(() => this.mouseHideDelay_ = null, 1000);
  }

  // One based row/column stored on the mouse event.
  e.terminalRow = parseInt((e.clientY - this.scrollPort_.visibleRowTopMargin) /
                           this.scrollPort_.characterSize.height) + 1;
  e.terminalColumn = parseInt(e.clientX /
                              this.scrollPort_.characterSize.width) + 1;

  if (e.type == 'mousedown' && e.terminalColumn > this.screenSize.width) {
    // Mousedown in the scrollbar area.
    return;
  }

  if (this.options_.cursorVisible && !reportMouseEvents) {
    // If the cursor is visible and we're not sending mouse events to the
    // host app, then we want to hide the terminal cursor when the mouse
    // cursor is over top.  This keeps the terminal cursor from interfering
    // with local text selection.
    if (e.terminalRow - 1 == this.screen_.cursorPosition.row &&
        e.terminalColumn - 1 == this.screen_.cursorPosition.column) {
      this.cursorNode_.style.display = 'none';
    } else if (this.cursorNode_.style.display == 'none') {
      this.cursorNode_.style.display = '';
    }
  }

  if (e.type == 'mousedown') {
    this.contextMenu.hide(e);

    if (e.altKey || !reportMouseEvents) {
      // If VT mouse reporting is disabled, or has been defeated with
      // alt-mousedown, then the mouse will act on the local selection.
      this.defeatMouseReports_ = true;
      this.setSelectionEnabled(true);
    } else {
      // Otherwise we defer ownership of the mouse to the VT.
      this.defeatMouseReports_ = false;
      this.document_.getSelection().collapseToEnd();
      this.setSelectionEnabled(false);
      e.preventDefault();
    }
  }

  if (!reportMouseEvents) {
    if (e.type == 'dblclick') {
      this.screen_.expandSelection(this.document_.getSelection());
      if (this.copyOnSelect)
        this.copySelectionToClipboard();
    }

    if (e.type == 'click' && !e.shiftKey && (e.ctrlKey || e.metaKey)) {
      // Debounce this event with the dblclick event.  If you try to doubleclick
      // a URL to open it, Chrome will fire click then dblclick, but we won't
      // have expanded the selection text at the first click event.
      clearTimeout(this.timeouts_.openUrl);
      this.timeouts_.openUrl = setTimeout(this.openSelectedUrl_.bind(this),
                                          500);
      return;
    }

    if (e.type == 'mousedown') {
      if (e.ctrlKey && e.button == 2 /* right button */) {
        e.preventDefault();
        this.contextMenu.show(e, this);
      } else if (e.button == this.mousePasteButton ||
          (this.mouseRightClickPaste && e.button == 2 /* right button */)) {
        if (!this.paste())
          console.warn('Could not paste manually due to web restrictions');
      }
    }

    if (e.type == 'mouseup' && e.button == 0 && this.copyOnSelect &&
        !this.document_.getSelection().isCollapsed) {
      this.copySelectionToClipboard();
    }

    if ((e.type == 'mousemove' || e.type == 'mouseup') &&
        this.scrollBlockerNode_.engaged) {
      // Disengage the scroll-blocker after one of these events.
      this.scrollBlockerNode_.engaged = false;
      this.scrollBlockerNode_.style.top = '-99px';
    }

    // Emulate arrow key presses via scroll wheel events.
    if (this.scrollWheelArrowKeys_ && !e.shiftKey &&
        this.keyboard.applicationCursor && !this.isPrimaryScreen()) {
      if (e.type == 'wheel') {
        const delta = this.scrollPort_.scrollWheelDelta(e);

        // Helper to turn a wheel event delta into a series of key presses.
        const deltaToArrows = (distance, charSize, arrowPos, arrowNeg) => {
          if (distance == 0) {
            return '';
          }

          // Convert the scroll distance into a number of rows/cols.
          const cells = lib.f.smartFloorDivide(Math.abs(distance), charSize);
          const data = '\x1bO' + (distance < 0 ? arrowNeg : arrowPos);
          return data.repeat(cells);
        };

        // The order between up/down and left/right doesn't really matter.
        this.io.sendString(
            // Up/down arrow keys.
            deltaToArrows(delta.y, this.scrollPort_.characterSize.height,
                          'A', 'B') +
            // Left/right arrow keys.
            deltaToArrows(delta.x, this.scrollPort_.characterSize.width,
                          'C', 'D')
        );

        e.preventDefault();
      }
    }
  } else /* if (this.reportMouseEvents) */ {
    if (!this.scrollBlockerNode_.engaged) {
      if (e.type == 'mousedown') {
        // Move the scroll-blocker into place if we want to keep the scrollport
        // from scrolling.
        this.scrollBlockerNode_.engaged = true;
        this.scrollBlockerNode_.style.top = (e.clientY - 5) + 'px';
        this.scrollBlockerNode_.style.left = (e.clientX - 5) + 'px';
      } else if (e.type == 'mousemove') {
        // Oh.  This means that drag-scroll was disabled AFTER the mouse down,
        // in which case it's too late to engage the scroll-blocker.
        this.document_.getSelection().collapseToEnd();
        e.preventDefault();
      }
    }

    this.onMouse(e);
  }

  if (e.type == 'mouseup' && this.document_.getSelection().isCollapsed) {
    // Restore this on mouseup in case it was temporarily defeated with a
    // alt-mousedown.  Only do this when the selection is empty so that
    // we don't immediately kill the users selection.
    this.defeatMouseReports_ = false;
  }
};

/**
 * Clients should override this if they care to know about mouse events.
 *
 * The event parameter will be a normal DOM mouse click event with additional
 * 'terminalRow' and 'terminalColumn' properties.
 *
 * @param {Event} e The mouse event to handle.
 */
hterm.Terminal.prototype.onMouse = function(e) { };

/**
 * React when focus changes.
 *
 * @param {boolean} focused True if focused, false otherwise.
 */
hterm.Terminal.prototype.onFocusChange_ = function(focused) {
  this.cursorNode_.setAttribute('focus', focused);
  this.restyleCursor_();

  if (this.reportFocus)
    this.io.sendString(focused === true ? '\x1b[I' : '\x1b[O');

  if (focused === true)
    this.closeBellNotifications_();
};

/**
 * React when the ScrollPort is scrolled.
 */
hterm.Terminal.prototype.onScroll_ = function() {
  this.scheduleSyncCursorPosition_();
};

/**
 * React when text is pasted into the scrollPort.
 *
 * @param {Event} e The DOM paste event to handle.
 */
hterm.Terminal.prototype.onPaste_ = function(e) {
  var data = e.text.replace(/\n/mg, '\r');
  if (this.options_.bracketedPaste) {
    // We strip out most escape sequences as they can cause issues (like
    // inserting an \x1b[201~ midstream).  We pass through whitespace
    // though: 0x08:\b 0x09:\t 0x0a:\n 0x0d:\r.
    // This matches xterm behavior.
    const filter = (data) => data.replace(/[\x00-\x07\x0b-\x0c\x0e-\x1f]/g, '');
    data = '\x1b[200~' + filter(data) + '\x1b[201~';
  }

  this.io.sendString(data);
};

/**
 * React when the user tries to copy from the scrollPort.
 *
 * @param {Event} e The DOM copy event.
 */
hterm.Terminal.prototype.onCopy_ = function(e) {
  if (!this.useDefaultWindowCopy) {
    e.preventDefault();
    setTimeout(this.copySelectionToClipboard.bind(this), 0);
  }
};

/**
 * React when the ScrollPort is resized.
 *
 * Note: This function should not directly contain code that alters the internal
 * state of the terminal.  That kind of code belongs in realizeWidth or
 * realizeHeight, so that it can be executed synchronously in the case of a
 * programmatic width change.
 */
hterm.Terminal.prototype.onResize_ = function() {
  var columnCount = Math.floor(this.scrollPort_.getScreenWidth() /
                               this.scrollPort_.characterSize.width) || 0;
  var rowCount = lib.f.smartFloorDivide(this.scrollPort_.getScreenHeight(),
                            this.scrollPort_.characterSize.height) || 0;

  if (columnCount <= 0 || rowCount <= 0) {
    // We avoid these situations since they happen sometimes when the terminal
    // gets removed from the document or during the initial load, and we can't
    // deal with that.
    // This can also happen if called before the scrollPort calculates the
    // character size, meaning we dived by 0 above and default to 0 values.
    return;
  }

  var isNewSize = (columnCount != this.screenSize.width ||
                   rowCount != this.screenSize.height);

  // We do this even if the size didn't change, just to be sure everything is
  // in sync.
  this.realizeSize_(columnCount, rowCount);
  this.showZoomWarning_(this.scrollPort_.characterSize.zoomFactor != 1);

  if (isNewSize)
    this.overlaySize();

  this.restyleCursor_();
  this.scheduleSyncCursorPosition_();
};

/**
 * Service the cursor blink timeout.
 */
hterm.Terminal.prototype.onCursorBlink_ = function() {
  if (!this.options_.cursorBlink) {
    delete this.timeouts_.cursorBlink;
    return;
  }

  if (this.cursorNode_.getAttribute('focus') == 'false' ||
      this.cursorNode_.style.opacity == '0') {
    this.cursorNode_.style.opacity = '1';
    this.timeouts_.cursorBlink = setTimeout(this.myOnCursorBlink_,
                                            this.cursorBlinkCycle_[0]);
  } else {
    this.cursorNode_.style.opacity = '0';
    this.timeouts_.cursorBlink = setTimeout(this.myOnCursorBlink_,
                                            this.cursorBlinkCycle_[1]);
  }
};

/**
 * Set the scrollbar-visible mode bit.
 *
 * If scrollbar-visible is on, the vertical scrollbar will be visible.
 * Otherwise it will not.
 *
 * Defaults to on.
 *
 * @param {boolean} state True to set scrollbar-visible mode, false to unset.
 */
hterm.Terminal.prototype.setScrollbarVisible = function(state) {
  this.scrollPort_.setScrollbarVisible(state);
};

/**
 * Set the scroll wheel move multiplier.  This will affect how fast the page
 * scrolls on wheel events.
 *
 * Defaults to 1.
 *
 * @param {number} multiplier The multiplier to set.
 */
hterm.Terminal.prototype.setScrollWheelMoveMultipler = function(multiplier) {
  this.scrollPort_.setScrollWheelMoveMultipler(multiplier);
};

/**
 * Close all web notifications created by terminal bells.
 */
hterm.Terminal.prototype.closeBellNotifications_ = function() {
  this.bellNotificationList_.forEach(function(n) {
      n.close();
    });
  this.bellNotificationList_.length = 0;
};

/**
 * Syncs the cursor position when the scrollport gains focus.
 */
hterm.Terminal.prototype.onScrollportFocus_ = function() {
  // If the cursor is offscreen we set selection to the last row on the screen.
  const topRowIndex = this.scrollPort_.getTopRowIndex();
  const bottomRowIndex = this.scrollPort_.getBottomRowIndex(topRowIndex);
  const selection = this.document_.getSelection();
  if (!this.syncCursorPosition_() && selection) {
    selection.collapse(this.getRowNode(bottomRowIndex));
  }
};
// SOURCE FILE: hterm/js/hterm_terminal_io.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

lib.rtdep('lib.encodeUTF8');

/**
 * Input/Output interface used by commands to communicate with the terminal.
 *
 * Commands like `nassh` and `crosh` receive an instance of this class as
 * part of their argv object.  This allows them to write to and read from the
 * terminal without exposing them to an entire hterm.Terminal instance.
 *
 * The active command must override the onVTKeystroke() and sendString() methods
 * of this class in order to receive keystrokes and send output to the correct
 * destination.
 *
 * Isolating commands from the terminal provides the following benefits:
 * - Provides a mechanism to save and restore onVTKeystroke and sendString
 *   handlers when invoking subcommands (see the push() and pop() methods).
 * - The isolation makes it easier to make changes in Terminal and supporting
 *   classes without affecting commands.
 * - In The Future commands may run in web workers where they would only be able
 *   to talk to a Terminal instance through an IPC mechanism.
 *
 * @param {hterm.Terminal}
 */
hterm.Terminal.IO = function(terminal) {
  this.terminal_ = terminal;

  // The IO object to restore on IO.pop().
  this.previousIO_ = null;

  // Any data this object accumulated while not active.
  this.buffered_ = '';
};

/**
 * Show the terminal overlay for a given amount of time.
 *
 * The terminal overlay appears in inverse video in a large font, centered
 * over the terminal.  You should probably keep the overlay message brief,
 * since it's in a large font and you probably aren't going to check the size
 * of the terminal first.
 *
 * @param {string} msg The text (not HTML) message to display in the overlay.
 * @param {number} opt_timeout The amount of time to wait before fading out
 *     the overlay.  Defaults to 1.5 seconds.  Pass null to have the overlay
 *     stay up forever (or until the next overlay).
 */
hterm.Terminal.IO.prototype.showOverlay = function(message, opt_timeout) {
  this.terminal_.showOverlay(message, opt_timeout);
};

/**
 * Hide the current overlay immediately.
 *
 * Useful when we show an overlay for an event with an unknown end time.
 */
hterm.Terminal.IO.prototype.hideOverlay = function() {
  this.terminal_.hideOverlay();
};

/**
 * Open an frame in the current terminal window, pointed to the specified
 * url.
 *
 * Eventually we'll probably need size/position/decoration options.
 * The user should also be able to move/resize the frame.
 *
 * @param {string} url The URL to load in the frame.
 * @param {Object} opt_options Optional frame options.  Not implemented.
 */
hterm.Terminal.IO.prototype.createFrame = function(url, opt_options) {
  return new hterm.Frame(this.terminal_, url, opt_options);
};

/**
 * Change the preference profile for the terminal.
 *
 * @param profileName {string} The name of the preference profile to activate.
 */
hterm.Terminal.IO.prototype.setTerminalProfile = function(profileName) {
  this.terminal_.setProfile(profileName);
};

/**
 * Create a new hterm.Terminal.IO instance and make it active on the Terminal
 * object associated with this instance.
 *
 * This is used to pass control of the terminal IO off to a subcommand.  The
 * IO.pop() method can be used to restore control when the subcommand completes.
 */
hterm.Terminal.IO.prototype.push = function() {
  var io = new hterm.Terminal.IO(this.terminal_);
  io.keyboardCaptured_ = this.keyboardCaptured_;

  io.columnCount = this.columnCount;
  io.rowCount = this.rowCount;

  io.previousIO_ = this.terminal_.io;
  this.terminal_.io = io;

  return io;
};

/**
 * Restore the Terminal's previous IO object.
 *
 * We'll flush out any queued data.
 */
hterm.Terminal.IO.prototype.pop = function() {
  this.terminal_.io = this.previousIO_;
  this.previousIO_.flush();
};

/**
 * Flush accumulated data.
 *
 * If we're not the active IO, the connected process might still be writing
 * data to us, but we won't be displaying it.  Flush any buffered data now.
 */
hterm.Terminal.IO.prototype.flush = function() {
  if (this.buffered_) {
    this.terminal_.interpret(this.buffered_);
    this.buffered_ = '';
  }
};

/**
 * Called when data needs to be sent to the current command.
 *
 * Clients should override this to receive notification of pending data.
 *
 * @param {string} string The data to send.
 */
hterm.Terminal.IO.prototype.sendString = function(string) {
  // Override this.
  console.log('Unhandled sendString: ' + string);
};

/**
 * Called when a terminal keystroke is detected.
 *
 * Clients should override this to receive notification of keystrokes.
 *
 * @param {string} string The VT key sequence.
 */
hterm.Terminal.IO.prototype.onVTKeystroke = function(string) {
  // Override this.
  console.log('Unobserverd VT keystroke: ' + JSON.stringify(string));
};

hterm.Terminal.IO.prototype.onTerminalResize_ = function(width, height) {
  var obj = this;
  while (obj) {
    obj.columnCount = width;
    obj.rowCount = height;
    obj = obj.previousIO_;
  }

  this.onTerminalResize(width, height);
};

/**
 * Called when terminal size is changed.
 *
 * Clients should override this to receive notification of resize.
 *
 * @param {string|integer} terminal width.
 * @param {string|integer} terminal height.
 */
hterm.Terminal.IO.prototype.onTerminalResize = function(width, height) {
  // Override this.
};

/**
 * Write a UTF-8 encoded byte string to the terminal.
 *
 * @param {string} string The UTF-8 encoded string to print.
 */
hterm.Terminal.IO.prototype.writeUTF8 = function(string) {
  // If another process has the foreground IO, buffer new data sent to this IO
  // (since it's in the background).  When we're made the foreground IO again,
  // we'll flush everything.
  if (this.terminal_.io != this) {
    this.buffered_ += string;
    return;
  }

  this.terminal_.interpret(string);
};

/**
 * Write a UTF-8 encoded byte string to the terminal followed by crlf.
 *
 * @param {string} string The UTF-8 encoded string to print.
 */
hterm.Terminal.IO.prototype.writelnUTF8 = function(string) {
  this.writeUTF8(string + '\r\n');
};

/**
 * Write a UTF-16 JavaScript string to the terminal.
 *
 * @param {string} string The string to print.
 */
hterm.Terminal.IO.prototype.print =
hterm.Terminal.IO.prototype.writeUTF16 = function(string) {
  this.writeUTF8(lib.encodeUTF8(string));
};

/**
 * Print a UTF-16 JavaScript string to the terminal followed by a newline.
 *
 * @param {string} string The string to print.
 */
hterm.Terminal.IO.prototype.println =
hterm.Terminal.IO.prototype.writelnUTF16 = function(string) {
  this.writelnUTF8(lib.encodeUTF8(string));
};
// SOURCE FILE: hterm/js/hterm_text_attributes.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

lib.rtdep('lib.colors');

/**
 * Constructor for TextAttribute objects.
 *
 * These objects manage a set of text attributes such as foreground/
 * background color, bold, faint, italic, blink, underline, and strikethrough.
 *
 * TextAttribute instances can be used to construct a DOM container implementing
 * the current attributes, or to test an existing DOM container for
 * compatibility with the current attributes.
 *
 * @constructor
 * @param {HTMLDocument} document The parent document to use when creating
 *     new DOM containers.
 */
hterm.TextAttributes = function(document) {
  this.document_ = document;
  // These variables contain the source of the color as either:
  // SRC_DEFAULT  (use context default)
  // rgb(...)     (true color form)
  // number       (representing the index from color palette to use)
  this.foregroundSource = this.SRC_DEFAULT;
  this.backgroundSource = this.SRC_DEFAULT;
  this.underlineSource = this.SRC_DEFAULT;

  // These properties cache the value in the color table, but foregroundSource
  // and backgroundSource contain the canonical values.
  this.foreground = this.DEFAULT_COLOR;
  this.background = this.DEFAULT_COLOR;
  this.underlineColor = this.DEFAULT_COLOR;

  this.defaultForeground = 'rgb(255, 255, 255)';
  this.defaultBackground = 'rgb(0, 0, 0)';

  // Any attributes added here that do not default to falsey (e.g. undefined or
  // null) require a bit more care.  createContainer has to always attach the
  // attribute so matchesContainer can work correctly.
  this.bold = false;
  this.faint = false;
  this.italic = false;
  this.blink = false;
  this.underline = false;
  this.strikethrough = false;
  this.inverse = false;
  this.invisible = false;
  this.wcNode = false;
  this.asciiNode = true;
  this.tileData = null;
  this.uri = null;
  this.uriId = null;

  this.colorPalette = null;
  this.resetColorPalette();
};

/**
 * If false, we ignore the bold attribute.
 *
 * This is used for fonts that have a bold version that is a different size
 * than the normal weight version.
 */
hterm.TextAttributes.prototype.enableBold = true;

/**
 * If true, use bright colors (if available) for bold text.
 *
 * This setting is independent of the enableBold setting.
 */
hterm.TextAttributes.prototype.enableBoldAsBright = true;

/**
 * A sentinel constant meaning "whatever the default color is in this context".
 */
hterm.TextAttributes.prototype.DEFAULT_COLOR = lib.f.createEnum('');

/**
 * A constant string used to specify that source color is context default.
 */
hterm.TextAttributes.prototype.SRC_DEFAULT = 'default';

/**
 * The document object which should own the DOM nodes created by this instance.
 *
 * @param {HTMLDocument} document The parent document.
 */
hterm.TextAttributes.prototype.setDocument = function(document) {
  this.document_ = document;
};

/**
 * Create a deep copy of this object.
 *
 * @return {hterm.TextAttributes} A deep copy of this object.
 */
hterm.TextAttributes.prototype.clone = function() {
  var rv = new hterm.TextAttributes(null);

  for (var key in this) {
    rv[key] = this[key];
  }

  rv.colorPalette = this.colorPalette.concat();
  return rv;
};

/**
 * Reset the current set of attributes.
 *
 * This does not affect the palette.  Use resetColorPalette() for that.
 * It also doesn't affect the tile data, it's not meant to.
 */
hterm.TextAttributes.prototype.reset = function() {
  this.foregroundSource = this.SRC_DEFAULT;
  this.backgroundSource = this.SRC_DEFAULT;
  this.underlineSource = this.SRC_DEFAULT;
  this.foreground = this.DEFAULT_COLOR;
  this.background = this.DEFAULT_COLOR;
  this.underlineColor = this.DEFAULT_COLOR;
  this.bold = false;
  this.faint = false;
  this.italic = false;
  this.blink = false;
  this.underline = false;
  this.strikethrough = false;
  this.inverse = false;
  this.invisible = false;
  this.wcNode = false;
  this.asciiNode = true;
  this.uri = null;
  this.uriId = null;
};

/**
 * Reset the color palette to the default state.
 */
hterm.TextAttributes.prototype.resetColorPalette = function() {
  this.colorPalette = lib.colors.colorPalette.concat();
  this.syncColors();
};

/**
 * Reset the color.
 *
 * @param {integer|string} index The color index in the palette to reset.
 */
hterm.TextAttributes.prototype.resetColor = function(index) {
  index = parseInt(index, 10);
  if (isNaN(index) || index >= this.colorPalette.length)
    return;

  this.colorPalette[index] = lib.colors.stockColorPalette[index];
  this.syncColors();
};

/**
 * Test if the current attributes describe unstyled text.
 *
 * @return {boolean} True if the current attributes describe unstyled text.
 */
hterm.TextAttributes.prototype.isDefault = function() {
  return (this.foregroundSource == this.SRC_DEFAULT &&
          this.backgroundSource == this.SRC_DEFAULT &&
          !this.bold &&
          !this.faint &&
          !this.italic &&
          !this.blink &&
          !this.underline &&
          !this.strikethrough &&
          !this.inverse &&
          !this.invisible &&
          !this.wcNode &&
          this.asciiNode &&
          this.tileData == null &&
          this.uri == null);
};

/**
 * Create a DOM container (a span or a text node) with a style to match the
 * current set of attributes.
 *
 * This method will create a plain text node if the text is unstyled, or
 * an HTML span if the text is styled.  Due to lack of monospace wide character
 * fonts on certain systems (e.g. Chrome OS), we need to put each wide character
 * in a span of CSS class '.wc-node' which has double column width.
 * Each vt_tiledata tile is also represented by a span with a single
 * character, with CSS classes '.tile' and '.tile_<glyph number>'.
 *
 * @param {string} opt_textContent Optional text content for the new container.
 * @return {HTMLNode} An HTML span or text nodes styled to match the current
 *     attributes.
 */
hterm.TextAttributes.prototype.createContainer = function(opt_textContent) {
  if (this.isDefault()) {
    // Only attach attributes where we need an explicit default for the
    // matchContainer logic below.
    const node = this.document_.createTextNode(opt_textContent);
    node.asciiNode = true;
    return node;
  }

  var span = this.document_.createElement('span');
  var style = span.style;
  var classes = [];

  if (this.foreground != this.DEFAULT_COLOR)
    style.color = this.foreground;

  if (this.background != this.DEFAULT_COLOR)
    style.backgroundColor = this.background;

  if (this.enableBold && this.bold)
    style.fontWeight = 'bold';

  if (this.faint)
    span.faint = true;

  if (this.italic)
    style.fontStyle = 'italic';

  if (this.blink) {
    classes.push('blink-node');
    span.blinkNode = true;
  }

  let textDecorationLine = '';
  span.underline = this.underline;
  if (this.underline) {
    textDecorationLine += ' underline';
    style.textDecorationStyle = this.underline;
  }
  if (this.underlineSource != this.SRC_DEFAULT)
    style.textDecorationColor = this.underlineColor;
  if (this.strikethrough) {
    textDecorationLine += ' line-through';
    span.strikethrough = true;
  }
  if (textDecorationLine)
    style.textDecorationLine = textDecorationLine;

  if (this.wcNode) {
    classes.push('wc-node');
    span.wcNode = true;
  }
  span.asciiNode = this.asciiNode;

  if (this.tileData != null) {
    classes.push('tile');
    classes.push('tile_' + this.tileData);
    span.tileNode = true;
  }

  if (opt_textContent)
    span.textContent = opt_textContent;

  if (this.uri) {
    classes.push('uri-node');
    span.uriId = this.uriId;
    span.title = this.uri;
    span.addEventListener('click', hterm.openUrl.bind(this, this.uri));
  }

  if (classes.length)
    span.className = classes.join(' ');

  return span;
};

/**
 * Tests if the provided object (string, span or text node) has the same
 * style as this TextAttributes instance.
 *
 * This indicates that text with these attributes could be inserted directly
 * into the target DOM node.
 *
 * For the purposes of this method, a string is considered a text node.
 *
 * @param {string|HTMLNode} obj The object to test.
 * @return {boolean} True if the provided container has the same style as
 *     this attributes instance.
 */
hterm.TextAttributes.prototype.matchesContainer = function(obj) {
  if (typeof obj == 'string' || obj.nodeType == Node.TEXT_NODE)
    return this.isDefault();

  var style = obj.style;

  // We don't want to put multiple characters in a wcNode or a tile.
  // See the comments in createContainer.
  // For attributes that default to false, we do not require that obj have them
  // declared, so always normalize them using !! (to turn undefined into false)
  // in the compares below.
  return (!(this.wcNode || obj.wcNode) &&
          this.asciiNode == obj.asciiNode &&
          !(this.tileData != null || obj.tileNode) &&
          this.uriId == obj.uriId &&
          this.foreground == style.color &&
          this.background == style.backgroundColor &&
          this.underlineColor == style.textDecorationColor &&
          (this.enableBold && this.bold) == !!style.fontWeight &&
          this.blink == !!obj.blinkNode &&
          this.italic == !!style.fontStyle &&
          this.underline == obj.underline &&
          !!this.strikethrough == !!obj.strikethrough);
};

hterm.TextAttributes.prototype.setDefaults = function(foreground, background) {
  this.defaultForeground = foreground;
  this.defaultBackground = background;

  this.syncColors();
};

/**
 * Updates foreground and background properties based on current indices and
 * other state.
 *
 * @param {string} terminalForeground The terminal foreground color for use as
 *     inverse text background.
 * @param {string} terminalBackground The terminal background color for use as
 *     inverse text foreground.
 *
 */
hterm.TextAttributes.prototype.syncColors = function() {
  function getBrightIndex(i) {
    if (i < 8) {
      // If the color is from the lower half of the ANSI 16, add 8.
      return i + 8;
    }

    // If it's not from the 16 color palette, ignore bold requests.  This
    // matches the behavior of gnome-terminal.
    return i;
  }

  // Expand the default color as makes sense.
  const getDefaultColor = (color, defaultColor) => {
    return color == this.DEFAULT_COLOR ? defaultColor : color;
  };

  var foregroundSource = this.foregroundSource;
  var backgroundSource = this.backgroundSource;

  if (this.enableBoldAsBright && this.bold) {
    if (Number.isInteger(foregroundSource)) {
      foregroundSource = getBrightIndex(foregroundSource);
    }
  }

  if (foregroundSource == this.SRC_DEFAULT)
    this.foreground = this.DEFAULT_COLOR;
  else if (Number.isInteger(foregroundSource))
    this.foreground = this.colorPalette[foregroundSource];
  else
    this.foreground = foregroundSource;

  if (this.faint) {
    const colorToMakeFaint =
        getDefaultColor(this.foreground, this.defaultForeground);
    this.foreground = lib.colors.mix(colorToMakeFaint, 'rgb(0, 0, 0)', 0.3333);
  }

  if (backgroundSource == this.SRC_DEFAULT)
    this.background = this.DEFAULT_COLOR;
  else if (Number.isInteger(backgroundSource))
    this.background = this.colorPalette[backgroundSource];
  else
    this.background = backgroundSource;

  // Once we've processed the bold-as-bright and faint attributes, swap.
  // This matches xterm/gnome-terminal.
  if (this.inverse) {
    const swp = getDefaultColor(this.foreground, this.defaultForeground);
    this.foreground = getDefaultColor(this.background, this.defaultBackground);
    this.background = swp;
  }

  // Process invisible settings last to keep it simple.
  if (this.invisible)
    this.foreground = this.background;

  if (this.underlineSource == this.SRC_DEFAULT)
    this.underlineColor = '';
  else if (Number.isInteger(this.underlineSource))
    this.underlineColor = this.colorPalette[this.underlineSource];
  else
    this.underlineColor = this.underlineSource;
};

/**
 * Static method used to test if the provided objects (strings, spans or
 * text nodes) have the same style.
 *
 * For the purposes of this method, a string is considered a text node.
 *
 * @param {string|HTMLNode} obj1 An object to test.
 * @param {string|HTMLNode} obj2 Another object to test.
 * @return {boolean} True if the containers have the same style.
 */
hterm.TextAttributes.containersMatch = function(obj1, obj2) {
  if (typeof obj1 == 'string')
    return hterm.TextAttributes.containerIsDefault(obj2);

  if (obj1.nodeType != obj2.nodeType)
    return false;

  if (obj1.nodeType == Node.TEXT_NODE)
    return true;

  var style1 = obj1.style;
  var style2 = obj2.style;

  return (style1.color == style2.color &&
          style1.backgroundColor == style2.backgroundColor &&
          style1.backgroundColor == style2.backgroundColor &&
          style1.fontWeight == style2.fontWeight &&
          style1.fontStyle == style2.fontStyle &&
          style1.textDecoration == style2.textDecoration &&
          style1.textDecorationColor == style2.textDecorationColor &&
          style1.textDecorationStyle == style2.textDecorationStyle &&
          style1.textDecorationLine == style2.textDecorationLine);
};

/**
 * Static method to test if a given DOM container represents unstyled text.
 *
 * For the purposes of this method, a string is considered a text node.
 *
 * @param {string|HTMLNode} obj1 An object to test.
 * @return {boolean} True if the object is unstyled.
 */
hterm.TextAttributes.containerIsDefault = function(obj) {
  return typeof obj == 'string'  || obj.nodeType == Node.TEXT_NODE;
};

/**
 * Static method to get the column width of a node's textContent.
 *
 * @param {HTMLElement} node The HTML element to get the width of textContent
 *     from.
 * @return {integer} The column width of the node's textContent.
 */
hterm.TextAttributes.nodeWidth = function(node) {
  if (!node.asciiNode) {
    return lib.wc.strWidth(node.textContent);
  } else {
    return node.textContent.length;
  }
};

/**
 * Static method to get the substr of a node's textContent.  The start index
 * and substr width are computed in column width.
 *
 * @param {HTMLElement} node The HTML element to get the substr of textContent
 *     from.
 * @param {integer} start The starting offset in column width.
 * @param {integer} width The width to capture in column width.
 * @return {integer} The extracted substr of the node's textContent.
 */
hterm.TextAttributes.nodeSubstr = function(node, start, width) {
  if (!node.asciiNode) {
    return lib.wc.substr(node.textContent, start, width);
  } else {
    return node.textContent.substr(start, width);
  }
};

/**
 * Static method to get the substring based of a node's textContent.  The
 * start index of end index are computed in column width.
 *
 * @param {HTMLElement} node The HTML element to get the substr of textContent
 *     from.
 * @param {integer} start The starting offset in column width.
 * @param {integer} end The ending offset in column width.
 * @return {integer} The extracted substring of the node's textContent.
 */
hterm.TextAttributes.nodeSubstring = function(node, start, end) {
  if (!node.asciiNode) {
    return lib.wc.substring(node.textContent, start, end);
  } else {
    return node.textContent.substring(start, end);
  }
};

/**
 * Static method to split a string into contiguous runs of single-width
 * characters and runs of double-width characters.
 *
 * @param {string} str The string to split.
 * @return {Array} An array of objects that contain substrings of str, where
 *     each substring is either a contiguous runs of single-width characters
 *     or a double-width character.  For objects that contain a double-width
 *     character, its wcNode property is set to true.  For objects that contain
 *     only ASCII content, its asciiNode property is set to true.
 */
hterm.TextAttributes.splitWidecharString = function(str) {
  var rv = [];
  var base = 0, length = 0, wcStrWidth = 0, wcCharWidth;
  var asciiNode = true;

  for (var i = 0; i < str.length;) {
    var c = str.codePointAt(i);
    var increment;
    if (c < 128) {
      wcStrWidth += 1;
      length += 1;
      increment = 1;
    } else {
      increment = (c <= 0xffff) ? 1 : 2;
      wcCharWidth = lib.wc.charWidth(c);
      if (wcCharWidth <= 1) {
        wcStrWidth += wcCharWidth;
        length += increment;
        asciiNode = false;
      } else {
        if (length) {
          rv.push({
            str: str.substr(base, length),
            asciiNode: asciiNode,
            wcStrWidth: wcStrWidth,
          });
          asciiNode = true;
          wcStrWidth = 0;
        }
        rv.push({
          str: str.substr(i, increment),
          wcNode: true,
          asciiNode: false,
          wcStrWidth: 2,
        });
        base = i + increment;
        length = 0;
      }
    }
    i += increment;
  }

  if (length) {
    rv.push({
      str: str.substr(base, length),
      asciiNode: asciiNode,
      wcStrWidth: wcStrWidth,
    });
  }

  return rv;
};
// SOURCE FILE: hterm/js/hterm_vt.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

lib.rtdep('lib.colors', 'lib.f', 'lib.UTF8Decoder',
          'hterm.VT.CharacterMap');

/**
 * Constructor for the VT escape sequence interpreter.
 *
 * The interpreter operates on a terminal object capable of performing cursor
 * move operations, painting characters, etc.
 *
 * This interpreter is intended to be compatible with xterm, though it
 * ignores some of the more esoteric escape sequences.
 *
 * Control sequences are documented in hterm/doc/ControlSequences.md.
 *
 * @param {hterm.Terminal} terminal Terminal to use with the interpreter.
 */
hterm.VT = function(terminal) {
  /**
   * The display terminal object associated with this virtual terminal.
   */
  this.terminal = terminal;

  terminal.onMouse = this.onTerminalMouse_.bind(this);
  this.mouseReport = this.MOUSE_REPORT_DISABLED;
  this.mouseCoordinates = this.MOUSE_COORDINATES_X10;

  // We only want to report mouse moves between cells, not between pixels.
  this.lastMouseDragResponse_ = null;

  // Parse state left over from the last parse.  You should use the parseState
  // instance passed into your parse routine, rather than reading
  // this.parseState_ directly.
  this.parseState_ = new hterm.VT.ParseState(this.parseUnknown_);

  // Any "leading modifiers" for the escape sequence, such as '?', ' ', or the
  // other modifiers handled in this.parseCSI_.
  this.leadingModifier_ = '';

  // Any "trailing modifiers".  Same character set as a leading modifier,
  // except these are found after the numeric arguments.
  this.trailingModifier_ = '';

  // Whether or not to respect the escape codes for setting terminal width.
  this.allowColumnWidthChanges_ = false;

  // The amount of time we're willing to wait for the end of an OSC sequence.
  this.oscTimeLimit_ = 20000;

  // Decoder to maintain UTF-8 decode state.
  this.utf8Decoder_ = new lib.UTF8Decoder();

  /**
   * Whether to accept the 8-bit control characters.
   *
   * An 8-bit control character is one with the eighth bit set.  These
   * didn't work on 7-bit terminals so they all have two byte equivalents.
   * Most hosts still only use the two-byte versions.
   *
   * We ignore 8-bit control codes by default.  This is in order to avoid
   * issues with "accidental" usage of codes that need to be terminated.
   * The "accident" usually involves cat'ing binary data.
   */
  this.enable8BitControl = false;

  /**
   * Whether to allow the OSC 52 sequence to write to the system clipboard.
   */
  this.enableClipboardWrite = true;

  /**
   * Respect the host's attempt to change the cursor blink status using
   * the DEC Private mode 12.
   */
  this.enableDec12 = false;

  /**
   * Respect the host's attempt to clear the scrollback buffer using CSI-J-3.
   */
  this.enableCsiJ3 = true;

  /**
   * The expected encoding method for data received from the host.
   */
  this.characterEncoding = 'utf-8';

  /**
   * If true, emit warnings when we encounter a control character or escape
   * sequence that we don't recognize or explicitly ignore.
   *
   * We disable this by default as the console logging can be expensive when
   * dumping binary files (e.g. `cat /dev/zero`) to the point where you can't
   * recover w/out restarting.
   */
  this.warnUnimplemented = false;

  /**
   * The set of available character maps (used by G0...G3 below).
   */
  this.characterMaps = new hterm.VT.CharacterMaps();

  /**
   * The default G0...G3 character maps.
   * We default to the US/ASCII map everywhere as that aligns with other
   * terminals, and it makes it harder to accidentally switch to the graphics
   * character map (Ctrl-N).  Any program that wants to use the graphics map
   * will usually select it anyways since there's no guarantee what state any
   * of the maps are in at any particular time.
   */
  this.G0 = this.G1 = this.G2 = this.G3 =
      this.characterMaps.getMap('B');

  /**
   * The 7-bit visible character set.
   *
   * This is a mapping from inbound data to display glyph.  The GL set
   * contains the 94 bytes from 0x21 to 0x7e.
   *
   * The default GL set is 'B', US ASCII.
   */
  this.GL = 'G0';

  /**
   * The 8-bit visible character set.
   *
   * This is a mapping from inbound data to display glyph.  The GR set
   * contains the 94 bytes from 0xa1 to 0xfe.
   */
  this.GR = 'G0';

  /**
   * The current encoding of the terminal.
   *
   * We only support ECMA-35 and UTF-8, so go with a boolean here.
   * The encoding can be locked too.
   */
  this.codingSystemUtf8_ = false;
  this.codingSystemLocked_ = false;

  // Construct a regular expression to match the known one-byte control chars.
  // This is used in parseUnknown_ to quickly scan a string for the next
  // control character.
  this.cc1Pattern_ = null;
  this.updateEncodingState_();
};

/**
 * No mouse events.
 */
hterm.VT.prototype.MOUSE_REPORT_DISABLED = 0;

/**
 * DECSET mode 9.
 *
 * Report mouse down events only.
 */
hterm.VT.prototype.MOUSE_REPORT_PRESS = 1;

/**
 * DECSET mode 1000.
 *
 * Report mouse down/up events only.
 */
hterm.VT.prototype.MOUSE_REPORT_CLICK = 2;

/**
 * DECSET mode 1002.
 *
 * Report mouse down/up and movement while a button is down.
 */
hterm.VT.prototype.MOUSE_REPORT_DRAG = 3;

/**
 * DEC mode for X10 coorindates (the default).
 */
hterm.VT.prototype.MOUSE_COORDINATES_X10 = 0;

/**
 * DEC mode 1005 for UTF-8 coorindates.
 */
hterm.VT.prototype.MOUSE_COORDINATES_UTF8 = 1;

/**
 * DEC mode 1006 for SGR coorindates.
 */
hterm.VT.prototype.MOUSE_COORDINATES_SGR = 2;

/**
 * ParseState constructor.
 *
 * This object tracks the current state of the parse.  It has fields for the
 * current buffer, position in the buffer, and the parse function.
 *
 * @param {function} defaultFunc The default parser function.
 * @param {string} opt_buf Optional string to use as the current buffer.
 */
hterm.VT.ParseState = function(defaultFunction, opt_buf) {
  this.defaultFunction = defaultFunction;
  this.buf = opt_buf || null;
  this.pos = 0;
  this.func = defaultFunction;
  this.args = [];
  // Whether any of the arguments in the args array have subarguments.
  // e.g. All CSI sequences are integer arguments separated by semi-colons,
  // so subarguments are further colon separated.
  this.subargs = null;
};

/**
 * Reset the parser function, buffer, and position.
 */
hterm.VT.ParseState.prototype.reset = function(opt_buf) {
  this.resetParseFunction();
  this.resetBuf(opt_buf || '');
  this.resetArguments();
};

/**
 * Reset the parser function only.
 */
hterm.VT.ParseState.prototype.resetParseFunction = function() {
  this.func = this.defaultFunction;
};

/**
 * Reset the buffer and position only.
 *
 * @param {string} buf Optional new value for buf, defaults to null.
 */
hterm.VT.ParseState.prototype.resetBuf = function(opt_buf) {
  this.buf = (typeof opt_buf == 'string') ? opt_buf : null;
  this.pos = 0;
};

/**
 * Reset the arguments list only.
 *
 * Typically we reset arguments before parsing a sequence that uses them rather
 * than always trying to make sure they're in a good state.  This can lead to
 * confusion during debugging where args from a previous sequence appear to be
 * "sticking around" in other sequences (which in reality don't use args).
 *
 * @param {string} opt_arg_zero Optional initial value for args[0].
 */
hterm.VT.ParseState.prototype.resetArguments = function(opt_arg_zero) {
  this.args.length = 0;
  if (typeof opt_arg_zero != 'undefined')
    this.args[0] = opt_arg_zero;
};

/**
 * Parse an argument as an integer.
 *
 * This assumes the inputs are already in the proper format.  e.g. This won't
 * handle non-numeric arguments.
 *
 * An "0" argument is treated the same as "" which means the default value will
 * be applied.  This is what most terminal sequences expect.
 *
 * @param {string} argstr The argument to parse directly.
 * @param {number=} defaultValue Default value if argstr is empty.
 * @return {number} The parsed value.
 */
hterm.VT.ParseState.prototype.parseInt = function(argstr, defaultValue) {
  if (defaultValue === undefined)
    defaultValue = 0;

  if (argstr) {
    const ret = parseInt(argstr, 10);
    // An argument of zero is treated as the default value.
    return ret == 0 ? defaultValue : ret;
  }
  return defaultValue;
};

/**
 * Get an argument as an integer.
 *
 * @param {number} argnum The argument number to retrieve.
 * @param {number=} defaultValue Default value if the argument is empty.
 * @return {number} The parsed value.
 */
hterm.VT.ParseState.prototype.iarg = function(argnum, defaultValue) {
  return this.parseInt(this.args[argnum], defaultValue);
};

/**
 * Check whether an argument has subarguments.
 *
 * @param {number} argnum The argument number to check.
 * @return {number} Whether the argument has subarguments.
 */
hterm.VT.ParseState.prototype.argHasSubargs = function(argnum) {
  return this.subargs && this.subargs[argnum];
};

/**
 * Mark an argument as having subarguments.
 *
 * @param {number} argnum The argument number that has subarguments.
 */
hterm.VT.ParseState.prototype.argSetSubargs = function(argnum) {
  if (this.subargs === null)
    this.subargs = {};
  this.subargs[argnum] = true;
};

/**
 * Advance the parse position.
 *
 * @param {integer} count The number of bytes to advance.
 */
hterm.VT.ParseState.prototype.advance = function(count) {
  this.pos += count;
};

/**
 * Return the remaining portion of the buffer without affecting the parse
 * position.
 *
 * @return {string} The remaining portion of the buffer.
 */
hterm.VT.ParseState.prototype.peekRemainingBuf = function() {
  return this.buf.substr(this.pos);
};

/**
 * Return the next single character in the buffer without affecting the parse
 * position.
 *
 * @return {string} The next character in the buffer.
 */
hterm.VT.ParseState.prototype.peekChar = function() {
  return this.buf.substr(this.pos, 1);
};

/**
 * Return the next single character in the buffer and advance the parse
 * position one byte.
 *
 * @return {string} The next character in the buffer.
 */
hterm.VT.ParseState.prototype.consumeChar = function() {
  return this.buf.substr(this.pos++, 1);
};

/**
 * Return true if the buffer is empty, or the position is past the end.
 */
hterm.VT.ParseState.prototype.isComplete = function() {
  return this.buf == null || this.buf.length <= this.pos;
};

/**
 * Reset the VT back to baseline state.
 */
hterm.VT.prototype.reset = function() {
  this.G0 = this.G1 = this.G2 = this.G3 =
      this.characterMaps.getMap('B');

  this.GL = 'G0';
  this.GR = 'G0';

  this.mouseReport = this.MOUSE_REPORT_DISABLED;
  this.mouseCoordinates = this.MOUSE_COORDINATES_X10;
  this.lastMouseDragResponse_ = null;
};

/**
 * Handle terminal mouse events.
 *
 * See the "Mouse Tracking" section of [xterm].
 */
hterm.VT.prototype.onTerminalMouse_ = function(e) {
  // Short circuit a few events to avoid unnecessary processing.
  if (this.mouseReport == this.MOUSE_REPORT_DISABLED)
    return;
  else if (this.mouseReport != this.MOUSE_REPORT_DRAG && e.type == 'mousemove')
    return;

  // Temporary storage for our response.
  var response;

  // Modifier key state.
  var mod = 0;
  if (this.mouseReport != this.MOUSE_REPORT_PRESS) {
    if (e.shiftKey)
      mod |= 4;
    if (e.metaKey || (this.terminal.keyboard.altIsMeta && e.altKey))
      mod |= 8;
    if (e.ctrlKey)
      mod |= 16;
  }

  // X & Y coordinate reporting.
  let x;
  let y;
  let limit = 255;
  switch (this.mouseCoordinates) {
    case this.MOUSE_COORDINATES_UTF8:
      // UTF-8 mode is the same as X10 but with higher limits.
      limit = 2047;
    case this.MOUSE_COORDINATES_X10:
      // X10 reports coordinates by encoding into strings.
      x = String.fromCharCode(lib.f.clamp(e.terminalColumn + 32, 32, limit));
      y = String.fromCharCode(lib.f.clamp(e.terminalRow + 32, 32, limit));
      break;
    case this.MOUSE_COORDINATES_SGR:
      // SGR reports coordinates by transmitting the numbers directly.
      x = e.terminalColumn;
      y = e.terminalRow;
      break;
  }

  switch (e.type) {
    case 'wheel':
      // Mouse wheel is treated as button 1 or 2 plus an additional 64.
      b = (((e.deltaY * -1) > 0) ? 0 : 1) + 64;
      b |= mod;
      if (this.mouseCoordinates == this.MOUSE_COORDINATES_SGR) {
        response = `\x1b[<${b};${x};${y}M`;
      } else {
        // X10 based modes (including UTF8) add 32 for legacy encoding reasons.
        response = '\x1b[M' + String.fromCharCode(b + 32) + x + y;
      }

      // Keep the terminal from scrolling.
      e.preventDefault();
      break;

    case 'mousedown':
      // Buttons are encoded as button number.
      var b = Math.min(e.button, 2);
      // X10 based modes (including UTF8) add 32 for legacy encoding reasons.
      if (this.mouseCoordinates != this.MOUSE_COORDINATES_SGR)
        b += 32;

      // And mix in the modifier keys.
      b |= mod;

      if (this.mouseCoordinates == this.MOUSE_COORDINATES_SGR)
        response = `\x1b[<${b};${x};${y}M`;
      else
        response = '\x1b[M' + String.fromCharCode(b) + x + y;
      break;

    case 'mouseup':
      if (this.mouseReport != this.MOUSE_REPORT_PRESS) {
        if (this.mouseCoordinates == this.MOUSE_COORDINATES_SGR) {
          // SGR mode can report the released button.
          response = `\x1b[<${e.button};${x};${y}m`;
        } else {
          // X10 mode has no indication of which button was released.
          response = '\x1b[M\x23' + x + y;
        }
      }
      break;

    case 'mousemove':
      if (this.mouseReport == this.MOUSE_REPORT_DRAG && e.buttons) {
        // Standard button bits.  The XTerm protocol only reports the first
        // button press (e.g. if left & right are pressed, right is ignored),
        // and it only supports the first three buttons.  If none of them are
        // pressed, then XTerm flags it as a release.  We'll do the same.
        // X10 based modes (including UTF8) add 32 for legacy encoding reasons.
        b = this.mouseCoordinates == this.MOUSE_COORDINATES_SGR ? 0 : 32;

        // Priority here matches XTerm: left, middle, right.
        if (e.buttons & 0x1) {
          // Report left button.
          b += 0;
        } else if (e.buttons & 0x4) {
          // Report middle button.
          b += 1;
        } else if (e.buttons & 0x2) {
          // Report right button.
          b += 2;
        } else {
          // Release higher buttons.
          b += 3;
        }

        // Add 32 to indicate mouse motion.
        b += 32;

        // And mix in the modifier keys.
        b |= mod;

        if (this.mouseCoordinates == this.MOUSE_COORDINATES_SGR)
          response = `\x1b[<${b};${x};${y}M`;
        else
          response = '\x1b[M' + String.fromCharCode(b) + x + y;

        // If we were going to report the same cell because we moved pixels
        // within, suppress the report.  This is what xterm does and cuts
        // down on duplicate messages.
        if (this.lastMouseDragResponse_ == response)
          response = '';
        else
          this.lastMouseDragResponse_ = response;
      }

      break;

    case 'click':
    case 'dblclick':
      break;

    default:
      console.error('Unknown mouse event: ' + e.type, e);
      break;
  }

  if (response)
    this.terminal.io.sendString(response);
};

/**
 * Interpret a string of characters, displaying the results on the associated
 * terminal object.
 *
 * The buffer will be decoded according to the 'receive-encoding' preference.
 */
hterm.VT.prototype.interpret = function(buf) {
  this.parseState_.resetBuf(this.decode(buf));

  while (!this.parseState_.isComplete()) {
    var func = this.parseState_.func;
    var pos = this.parseState_.pos;
    var buf = this.parseState_.buf;

    this.parseState_.func.call(this, this.parseState_);

    if (this.parseState_.func == func && this.parseState_.pos == pos &&
        this.parseState_.buf == buf) {
      throw 'Parser did not alter the state!';
    }
  }
};

/**
 * Decode a string according to the 'receive-encoding' preference.
 */
hterm.VT.prototype.decode = function(str) {
  if (this.characterEncoding == 'utf-8')
    return this.decodeUTF8(str);

  return str;
};

/**
 * Encode a UTF-16 string as UTF-8.
 *
 * See also: https://en.wikipedia.org/wiki/UTF-16
 */
hterm.VT.prototype.encodeUTF8 = function(str) {
  return lib.encodeUTF8(str);
};

/**
 * Decode a UTF-8 string into UTF-16.
 */
hterm.VT.prototype.decodeUTF8 = function(str) {
  return this.utf8Decoder_.decode(str);
};

/**
 * Set the encoding of the terminal.
 *
 * @param {string} encoding The name of the encoding to set.
 */
hterm.VT.prototype.setEncoding = function(encoding) {
  switch (encoding) {
    default:
      console.warn('Invalid value for "terminal-encoding": ' + encoding);
      // Fall through.
    case 'iso-2022':
      this.codingSystemUtf8_ = false;
      this.codingSystemLocked_ = false;
      break;
    case 'utf-8-locked':
      this.codingSystemUtf8_ = true;
      this.codingSystemLocked_ = true;
      break;
    case 'utf-8':
      this.codingSystemUtf8_ = true;
      this.codingSystemLocked_ = false;
      break;
  }

  this.updateEncodingState_();
};

/**
 * Refresh internal state when the encoding changes.
 */
hterm.VT.prototype.updateEncodingState_ = function() {
  // If we're in UTF8 mode, don't suport 8-bit escape sequences as we'll never
  // see those -- everything should be UTF8!
  var cc1 = Object.keys(hterm.VT.CC1)
      .filter((e) => !this.codingSystemUtf8_ || e.charCodeAt() < 0x80)
      .map((e) => '\\x' + lib.f.zpad(e.charCodeAt().toString(16), 2))
      .join('');
  this.cc1Pattern_ = new RegExp(`[${cc1}]`);
};

/**
 * The default parse function.
 *
 * This will scan the string for the first 1-byte control character (C0/C1
 * characters from [CTRL]).  Any plain text coming before the code will be
 * printed to the terminal, then the control character will be dispatched.
 */
hterm.VT.prototype.parseUnknown_ = function(parseState) {
  var self = this;

  function print(str) {
    if (!self.codingSystemUtf8_ && self[self.GL].GL)
      str = self[self.GL].GL(str);

    self.terminal.print(str);
  }

  // Search for the next contiguous block of plain text.
  var buf = parseState.peekRemainingBuf();
  var nextControl = buf.search(this.cc1Pattern_);

  if (nextControl == 0) {
    // We've stumbled right into a control character.
    this.dispatch('CC1', buf.substr(0, 1), parseState);
    parseState.advance(1);
    return;
  }

  if (nextControl == -1) {
    // There are no control characters in this string.
    print(buf);
    parseState.reset();
    return;
  }

  print(buf.substr(0, nextControl));
  this.dispatch('CC1', buf.substr(nextControl, 1), parseState);
  parseState.advance(nextControl + 1);
};

/**
 * Parse a Control Sequence Introducer code and dispatch it.
 *
 * See [CSI] for some useful information about these codes.
 */
hterm.VT.prototype.parseCSI_ = function(parseState) {
  var ch = parseState.peekChar();
  var args = parseState.args;

  const finishParsing = () => {
    // Resetting the arguments isn't strictly necessary, but it makes debugging
    // less confusing (otherwise args will stick around until the next sequence
    // that needs arguments).
    parseState.resetArguments();
    // We need to clear subargs since we explicitly set it.
    parseState.subargs = null;
    parseState.resetParseFunction();
  };

  if (ch >= '@' && ch <= '~') {
    // This is the final character.
    this.dispatch('CSI', this.leadingModifier_ + this.trailingModifier_ + ch,
                  parseState);
    finishParsing();

  } else if (ch == ';') {
    // Parameter delimiter.
    if (this.trailingModifier_) {
      // Parameter delimiter after the trailing modifier.  That's a paddlin'.
      finishParsing();

    } else {
      if (!args.length) {
        // They omitted the first param, we need to supply it.
        args.push('');
      }

      args.push('');
    }

  } else if (ch >= '0' && ch <= '9' || ch == ':') {
    // Next byte in the current parameter.

    if (this.trailingModifier_) {
      // Numeric parameter after the trailing modifier.  That's a paddlin'.
      finishParsing();
    } else {
      if (!args.length) {
        args[0] = ch;
      } else {
        args[args.length - 1] += ch;
      }

      // Possible sub-parameters.
      if (ch == ':')
        parseState.argSetSubargs(args.length - 1);
    }

  } else if (ch >= ' ' && ch <= '?') {
    // Modifier character.
    if (!args.length) {
      this.leadingModifier_ += ch;
    } else {
      this.trailingModifier_ += ch;
    }

  } else if (this.cc1Pattern_.test(ch)) {
    // Control character.
    this.dispatch('CC1', ch, parseState);

  } else {
    // Unexpected character in sequence, bail out.
    finishParsing();
  }

  parseState.advance(1);
};

/**
 * Skip over the string until the next String Terminator (ST, 'ESC \') or
 * Bell (BEL, '\x07').
 *
 * The string is accumulated in parseState.args[0].  Make sure to reset the
 * arguments (with parseState.resetArguments) before starting the parse.
 *
 * You can detect that parsing in complete by checking that the parse
 * function has changed back to the default parse function.
 *
 * @return {boolean} If true, parsing is ongoing or complete.  If false, we've
 *     exceeded the max string sequence.
 */
hterm.VT.prototype.parseUntilStringTerminator_ = function(parseState) {
  var buf = parseState.peekRemainingBuf();
  var args = parseState.args;
  // Since we might modify parse state buffer locally, if we want to advance
  // the parse state buffer later on, we need to know how many chars we added.
  let bufInserted = 0;

  if (!args.length) {
    args[0] = '';
    args[1] = new Date();
  } else {
    // If our saved buffer ends with an escape, it's because we were hoping
    // it's an ST split across two buffers.  Move it from our saved buffer
    // to the start of our current buffer for processing anew.
    if (args[0].slice(-1) == '\x1b') {
      args[0] = args[0].slice(0, -1);
      buf = '\x1b' + buf;
      bufInserted = 1;
    }
  }

  const nextTerminator = buf.search(/[\x1b\x07]/);
  const terminator = buf[nextTerminator];
  let foundTerminator;

  // If the next escape we see is not a start of a ST, fall through.  This will
  // either be invalid (embedded escape), or we'll queue it up (wait for \\).
  if (terminator == '\x1b' && buf[nextTerminator + 1] != '\\')
    foundTerminator = false;
  else
    foundTerminator = (nextTerminator != -1);

  if (!foundTerminator) {
    // No terminator here, have to wait for the next string.

    args[0] += buf;

    var abortReason;

    // Special case: If our buffering happens to split the ST (\e\\), we have to
    // buffer the content temporarily.  So don't reject a trailing escape here,
    // instead we let it timeout or be rejected in the next pass.
    if (terminator == '\x1b' && nextTerminator != buf.length - 1)
      abortReason = 'embedded escape: ' + nextTerminator;

    if (new Date() - args[1] > this.oscTimeLimit_)
      abortReason = 'timeout expired: ' + (new Date() - args[1]);

    if (abortReason) {
      if (this.warnUnimplemented)
        console.log('parseUntilStringTerminator_: aborting: ' + abortReason,
                    args[0]);
      parseState.reset(args[0]);
      return false;
    }

    parseState.advance(buf.length - bufInserted);
    return true;
  }

  args[0] += buf.substr(0, nextTerminator);

  parseState.resetParseFunction();
  parseState.advance(nextTerminator +
                     (terminator == '\x1b' ? 2 : 1) - bufInserted);

  return true;
};

/**
 * Dispatch to the function that handles a given CC1, ESC, or CSI or VT52 code.
 */
hterm.VT.prototype.dispatch = function(type, code, parseState) {
  var handler = hterm.VT[type][code];
  if (!handler) {
    if (this.warnUnimplemented)
      console.warn('Unknown ' + type + ' code: ' + JSON.stringify(code));
    return;
  }

  if (handler == hterm.VT.ignore) {
    if (this.warnUnimplemented)
      console.warn('Ignored ' + type + ' code: ' + JSON.stringify(code));
    return;
  }

  if (parseState.subargs && !handler.supportsSubargs) {
    if (this.warnUnimplemented)
      console.warn('Ignored ' + type + ' code w/subargs: ' + JSON.stringify(code));
    return;
  }

  if (type == 'CC1' && code > '\x7f' && !this.enable8BitControl) {
    // It's kind of a hack to put this here, but...
    //
    // If we're dispatching a 'CC1' code, and it's got the eighth bit set,
    // but we're not supposed to handle 8-bit codes?  Just ignore it.
    //
    // This prevents an errant (DCS, '\x90'), (OSC, '\x9d'), (PM, '\x9e') or
    // (APC, '\x9f') from locking up the terminal waiting for its expected
    // (ST, '\x9c') or (BEL, '\x07').
    console.warn('Ignoring 8-bit control code: 0x' +
                 code.charCodeAt(0).toString(16));
    return;
  }

  handler.apply(this, [parseState, code]);
};

/**
 * Set one of the ANSI defined terminal mode bits.
 *
 * Invoked in response to SM/RM.
 *
 * Unexpected and unimplemented values are silently ignored.
 */
hterm.VT.prototype.setANSIMode = function(code, state) {
  if (code == 4) {  // Insert Mode (IRM)
    this.terminal.setInsertMode(state);
  } else if (code == 20) {  // Automatic Newline (LNM)
    this.terminal.setAutoCarriageReturn(state);
  } else if (this.warnUnimplemented) {
    console.warn('Unimplemented ANSI Mode: ' + code);
  }
};

/**
 * Set or reset one of the DEC Private modes.
 *
 * Invoked in response to DECSET/DECRST.
 */
hterm.VT.prototype.setDECMode = function(code, state) {
  switch (parseInt(code, 10)) {
    case 1:  // DECCKM
      this.terminal.keyboard.applicationCursor = state;
      break;

    case 3:  // DECCOLM
      if (this.allowColumnWidthChanges_) {
        this.terminal.setWidth(state ? 132 : 80);

        this.terminal.clearHome();
        this.terminal.setVTScrollRegion(null, null);
      }
      break;

    case 5:  // DECSCNM
      this.terminal.setReverseVideo(state);
      break;

    case 6:  // DECOM
      this.terminal.setOriginMode(state);
      break;

    case 7:  // DECAWM
      this.terminal.setWraparound(state);
      break;

    case 9:  // Report on mouse down events only (X10).
      this.mouseReport = (
          state ? this.MOUSE_REPORT_PRESS : this.MOUSE_REPORT_DISABLED);
      this.terminal.syncMouseStyle();
      break;

    case 12:  // Start blinking cursor
      if (this.enableDec12)
        this.terminal.setCursorBlink(state);
      break;

    case 25:  // DECTCEM
      this.terminal.setCursorVisible(state);
      break;

    case 30:  // Show scrollbar
      this.terminal.setScrollbarVisible(state);
      break;

    case 40:  // Allow 80 - 132 (DECCOLM) Mode
      this.terminal.allowColumnWidthChanges_ = state;
      break;

    case 45:  // Reverse-wraparound Mode
      this.terminal.setReverseWraparound(state);
      break;

    case 67:  // Backarrow key sends backspace (DECBKM)
      this.terminal.keyboard.backspaceSendsBackspace = state;
      break;

    case 1000:  // Report on mouse clicks only (X11).
      this.mouseReport = (
          state ? this.MOUSE_REPORT_CLICK : this.MOUSE_REPORT_DISABLED);
      this.terminal.syncMouseStyle();
      break;

    case 1002:  // Report on mouse clicks and drags
      this.mouseReport = (
          state ? this.MOUSE_REPORT_DRAG : this.MOUSE_REPORT_DISABLED);
      this.terminal.syncMouseStyle();
      break;

    case 1004:  // Report on window focus change.
      this.terminal.reportFocus = state;
      break;

    case 1005:  // Extended coordinates in UTF-8 mode.
      this.mouseCoordinates = (
          state ? this.MOUSE_COORDINATES_UTF8 : this.MOUSE_COORDINATES_X10);
      break;

    case 1006:  // Extended coordinates in SGR mode.
      this.mouseCoordinates = (
          state ? this.MOUSE_COORDINATES_SGR : this.MOUSE_COORDINATES_X10);
      break;

    case 1007:  // Enable Alternate Scroll Mode.
      this.terminal.scrollWheelArrowKeys_ = state;
      break;

    case 1010:  // Scroll to bottom on tty output
      this.terminal.scrollOnOutput = state;
      break;

    case 1011:  // Scroll to bottom on key press
      this.terminal.scrollOnKeystroke = state;
      break;

    case 1036:  // Send ESC when Meta modifies a key
      this.terminal.keyboard.metaSendsEscape = state;
      break;

    case 1039:  // Send ESC when Alt modifies a key
      if (state) {
        if (!this.terminal.keyboard.previousAltSendsWhat_) {
          this.terminal.keyboard.previousAltSendsWhat_ =
              this.terminal.keyboard.altSendsWhat;
          this.terminal.keyboard.altSendsWhat = 'escape';
        }
      } else if (this.terminal.keyboard.previousAltSendsWhat_) {
        this.terminal.keyboard.altSendsWhat =
            this.terminal.keyboard.previousAltSendsWhat_;
        this.terminal.keyboard.previousAltSendsWhat_ = null;
      }
      break;

    case 47:  // Use Alternate Screen Buffer
    case 1047:
      this.terminal.setAlternateMode(state);
      break;

    case 1048:  // Save cursor as in DECSC.
      if (state)
        this.terminal.saveCursorAndState();
      else
        this.terminal.restoreCursorAndState();
      break;

    case 1049:  // 1047 + 1048 + clear.
      if (state) {
        this.terminal.saveCursorAndState();
        this.terminal.setAlternateMode(state);
        this.terminal.clear();
      } else {
        this.terminal.setAlternateMode(state);
        this.terminal.restoreCursorAndState();
      }

      break;

    case 2004:  // Bracketed paste mode.
      this.terminal.setBracketedPaste(state);
      break;

    default:
      if (this.warnUnimplemented)
        console.warn('Unimplemented DEC Private Mode: ' + code);
      break;
  }
};

/**
 * Function shared by control characters and escape sequences that are
 * ignored.
 */
hterm.VT.ignore = function() {};

/**
 * Collection of control characters expressed in a single byte.
 *
 * This includes the characters from the C0 and C1 sets (see [CTRL]) that we
 * care about.  Two byte versions of the C1 codes are defined in the
 * hterm.VT.ESC collection.
 *
 * The 'CC1' mnemonic here refers to the fact that these are one-byte Control
 * Codes.  It's only used in this source file and not defined in any of the
 * referenced documents.
 */
hterm.VT.CC1 = {};

/**
 * Collection of two-byte and three-byte sequences starting with ESC.
 */
hterm.VT.ESC = {};

/**
 * Collection of CSI (Control Sequence Introducer) sequences.
 *
 * These sequences begin with 'ESC [', and may take zero or more arguments.
 */
hterm.VT.CSI = {};

/**
 * Collection of OSC (Operating System Control) sequences.
 *
 * These sequences begin with 'ESC ]', followed by a function number and a
 * string terminated by either ST or BEL.
 */
hterm.VT.OSC = {};

/**
 * Collection of VT52 sequences.
 *
 * When in VT52 mode, other sequences are disabled.
 */
hterm.VT.VT52 = {};

/**
 * Null (NUL).
 *
 * Silently ignored.
 */
hterm.VT.CC1['\x00'] = hterm.VT.ignore;

/**
 * Enquiry (ENQ).
 *
 * Transmit answerback message.
 *
 * The default answerback message in xterm is an empty string, so we just
 * ignore this.
 */
hterm.VT.CC1['\x05'] = hterm.VT.ignore;

/**
 * Ring Bell (BEL).
 */
hterm.VT.CC1['\x07'] = function() {
  this.terminal.ringBell();
};

/**
 * Backspace (BS).
 *
 * Move the cursor to the left one character position, unless it is at the
 * left margin, in which case no action occurs.
 */
hterm.VT.CC1['\x08'] = function() {
  this.terminal.cursorLeft(1);
};

/**
 * Horizontal Tab (HT).
 *
 * Move the cursor to the next tab stop, or to the right margin if no further
 * tab stops are present on the line.
 */
hterm.VT.CC1['\x09'] = function() {
  this.terminal.forwardTabStop();
};

/**
 * Line Feed (LF).
 *
 * This code causes a line feed or a new line operation.  See Automatic
 * Newline (LNM).
 */
hterm.VT.CC1['\x0a'] = function() {
  this.terminal.formFeed();
};

/**
 * Vertical Tab (VT).
 *
 * Interpreted as LF.
 */
hterm.VT.CC1['\x0b'] = hterm.VT.CC1['\x0a'];

/**
 * Form Feed (FF).
 *
 * Interpreted as LF.
 */
hterm.VT.CC1['\x0c'] = hterm.VT.CC1['\x0a'];

/**
 * Carriage Return (CR).
 *
 * Move cursor to the left margin on the current line.
 */
hterm.VT.CC1['\x0d'] = function() {
  this.terminal.setCursorColumn(0);
};

/**
 * Shift Out (SO), aka Lock Shift 0 (LS1).
 *
 * Invoke G1 character set in GL.
 */
hterm.VT.CC1['\x0e'] = function() {
  this.GL = 'G1';
};

/**
 * Shift In (SI), aka Lock Shift 0 (LS0).
 *
 * Invoke G0 character set in GL.
 */
hterm.VT.CC1['\x0f'] = function() {
  this.GL = 'G0';
};

/**
 * Transmit On (XON).
 *
 * Not currently implemented.
 *
 * TODO(rginda): Implement?
 */
hterm.VT.CC1['\x11'] = hterm.VT.ignore;

/**
 * Transmit Off (XOFF).
 *
 * Not currently implemented.
 *
 * TODO(rginda): Implement?
 */
hterm.VT.CC1['\x13'] = hterm.VT.ignore;

/**
 * Cancel (CAN).
 *
 * If sent during a control sequence, the sequence is immediately terminated
 * and not executed.
 *
 * It also causes the error character to be displayed.
 */
hterm.VT.CC1['\x18'] = function(parseState) {
  // If we've shifted in the G1 character set, shift it back out to
  // the default character set.
  if (this.GL == 'G1') {
    this.GL = 'G0';
  }
  parseState.resetParseFunction();
  this.terminal.print('?');
};

/**
 * Substitute (SUB).
 *
 * Interpreted as CAN.
 */
hterm.VT.CC1['\x1a'] = hterm.VT.CC1['\x18'];

/**
 * Escape (ESC).
 */
hterm.VT.CC1['\x1b'] = function(parseState) {
  function parseESC(parseState) {
    var ch = parseState.consumeChar();

    if (ch == '\x1b')
      return;

    this.dispatch('ESC', ch, parseState);

    if (parseState.func == parseESC)
      parseState.resetParseFunction();
  }

  parseState.func = parseESC;
};

/**
 * Delete (DEL).
 */
hterm.VT.CC1['\x7f'] = hterm.VT.ignore;

// 8 bit control characters and their two byte equivalents, below...

/**
 * Index (IND).
 *
 * Like newline, only keep the X position
 */
hterm.VT.CC1['\x84'] =
hterm.VT.ESC['D'] = function() {
  this.terminal.lineFeed();
};

/**
 * Next Line (NEL).
 *
 * Like newline, but doesn't add lines.
 */
hterm.VT.CC1['\x85'] =
hterm.VT.ESC['E'] = function() {
  this.terminal.setCursorColumn(0);
  this.terminal.cursorDown(1);
};

/**
 * Horizontal Tabulation Set (HTS).
 */
hterm.VT.CC1['\x88'] =
hterm.VT.ESC['H'] = function() {
  this.terminal.setTabStop(this.terminal.getCursorColumn());
};

/**
 * Reverse Index (RI).
 *
 * Move up one line.
 */
hterm.VT.CC1['\x8d'] =
hterm.VT.ESC['M'] = function() {
  this.terminal.reverseLineFeed();
};

/**
 * Single Shift 2 (SS2).
 *
 * Select of G2 Character Set for the next character only.
 *
 * Not currently implemented.
 */
hterm.VT.CC1['\x8e'] =
hterm.VT.ESC['N'] = hterm.VT.ignore;

/**
 * Single Shift 3 (SS3).
 *
 * Select of G3 Character Set for the next character only.
 *
 * Not currently implemented.
 */
hterm.VT.CC1['\x8f'] =
hterm.VT.ESC['O'] = hterm.VT.ignore;

/**
 * Device Control String (DCS).
 *
 * Indicate a DCS sequence.  See Device-Control functions in [XTERM].
 * Not currently implemented.
 *
 * TODO(rginda): Consider implementing DECRQSS, the rest don't seem applicable.
 */
hterm.VT.CC1['\x90'] =
hterm.VT.ESC['P'] = function(parseState) {
  parseState.resetArguments();
  parseState.func = this.parseUntilStringTerminator_;
};

/**
 * Start of Guarded Area (SPA).
 *
 * Will not implement.
 */
hterm.VT.CC1['\x96'] =
hterm.VT.ESC['V'] = hterm.VT.ignore;

/**
 * End of Guarded Area (EPA).
 *
 * Will not implement.
 */
hterm.VT.CC1['\x97'] =
hterm.VT.ESC['W'] = hterm.VT.ignore;

/**
 * Start of String (SOS).
 *
 * Will not implement.
 */
hterm.VT.CC1['\x98'] =
hterm.VT.ESC['X'] = hterm.VT.ignore;

/**
 * Single Character Introducer (SCI, also DECID).
 *
 * Return Terminal ID.  Obsolete form of 'ESC [ c' (DA).
 */
hterm.VT.CC1['\x9a'] =
hterm.VT.ESC['Z'] = function() {
  this.terminal.io.sendString('\x1b[?1;2c');
};

/**
 * Control Sequence Introducer (CSI).
 *
 * The lead into most escape sequences.  See [CSI].
 */
hterm.VT.CC1['\x9b'] =
hterm.VT.ESC['['] = function(parseState) {
  parseState.resetArguments();
  this.leadingModifier_ = '';
  this.trailingModifier_ = '';
  parseState.func = this.parseCSI_;
};

/**
 * String Terminator (ST).
 *
 * Used to terminate DCS/OSC/PM/APC commands which may take string arguments.
 *
 * We don't directly handle it here, as it's only used to terminate other
 * sequences.  See the 'parseUntilStringTerminator_' method.
 */
hterm.VT.CC1['\x9c'] =
hterm.VT.ESC['\\'] = hterm.VT.ignore;

/**
 * Operating System Command (OSC).
 *
 * Commands relating to the operating system.
 */
hterm.VT.CC1['\x9d'] =
hterm.VT.ESC[']'] = function(parseState) {
  parseState.resetArguments();

  function parseOSC(parseState) {
    if (!this.parseUntilStringTerminator_(parseState)) {
      // The string sequence was too long.
      return;
    }

    if (parseState.func == parseOSC) {
      // We're not done parsing the string yet.
      return;
    }

    // We're done.
    var ary = parseState.args[0].match(/^(\d+);(.*)$/);
    if (ary) {
      parseState.args[0] = ary[2];
      this.dispatch('OSC', ary[1], parseState);
    } else {
      console.warn('Invalid OSC: ' + JSON.stringify(parseState.args[0]));
    }

    // Resetting the arguments isn't strictly necessary, but it makes debugging
    // less confusing (otherwise args will stick around until the next sequence
    // that needs arguments).
    parseState.resetArguments();
  }

  parseState.func = parseOSC;
};

/**
 * Privacy Message (PM).
 *
 * Will not implement.
 */
hterm.VT.CC1['\x9e'] =
hterm.VT.ESC['^'] = function(parseState) {
  parseState.resetArguments();
  parseState.func = this.parseUntilStringTerminator_;
};

/**
 * Application Program Control (APC).
 *
 * Will not implement.
 */
hterm.VT.CC1['\x9f'] =
hterm.VT.ESC['_'] = function(parseState) {
  parseState.resetArguments();
  parseState.func = this.parseUntilStringTerminator_;
};

/**
 * ESC \x20 - Unclear to me where these originated, possibly in xterm.
 *
 * Not currently implemented:
 *   ESC \x20 F - Select 7 bit escape codes in responses (S7C1T).
 *   ESC \x20 G - Select 8 bit escape codes in responses (S8C1T).
 *                NB: We currently assume S7C1T always.
 *
 * Will not implement:
 *   ESC \x20 L - Set ANSI conformance level 1.
 *   ESC \x20 M - Set ANSI conformance level 2.
 *   ESC \x20 N - Set ANSI conformance level 3.
 */
hterm.VT.ESC['\x20'] = function(parseState) {
  parseState.func = function(parseState) {
    var ch = parseState.consumeChar();
    if (this.warnUnimplemented)
      console.warn('Unimplemented sequence: ESC 0x20 ' + ch);
    parseState.resetParseFunction();
  };
};

/**
 * DEC 'ESC #' sequences.
 */
hterm.VT.ESC['#'] = function(parseState) {
  parseState.func = function(parseState) {
    var ch = parseState.consumeChar();
    if (ch == '8') {
      // DEC Screen Alignment Test (DECALN).
      this.terminal.setCursorPosition(0, 0);
      this.terminal.fill('E');
    }

    parseState.resetParseFunction();
  };
};

/**
 * Designate Other Coding System (DOCS).
 */
hterm.VT.ESC['%'] = function(parseState) {
  parseState.func = function(parseState) {
    var ch = parseState.consumeChar();

    // If we've locked the encoding, then just eat the bytes and return.
    if (this.codingSystemLocked_) {
      if (ch == '/')
        parseState.consumeChar();
      parseState.resetParseFunction();
      return;
    }

    // Process the encoding requests.
    switch (ch) {
      case '@':
        // Switch to ECMA 35.
        this.setEncoding('iso-2022');
        break;

      case 'G':
        // Switch to UTF-8.
        this.setEncoding('utf-8');
        break;

      case '/':
        // One way transition to something else.
        ch = parseState.consumeChar();
        switch (ch) {
          case 'G':  // UTF-8 Level 1.
          case 'H':  // UTF-8 Level 2.
          case 'I':  // UTF-8 Level 3.
            // We treat all UTF-8 levels the same.
            this.setEncoding('utf-8-locked');
            break;

          default:
            if (this.warnUnimplemented)
              console.warn('Unknown ESC % / argument: ' + JSON.stringify(ch));
            break;
        }
        break;

      default:
        if (this.warnUnimplemented)
          console.warn('Unknown ESC % argument: ' + JSON.stringify(ch));
        break;
    }

    parseState.resetParseFunction();
  };
};

/**
 * Character Set Selection (SCS).
 *
 *   ESC ( Ps - Set G0 character set (VT100).
 *   ESC ) Ps - Set G1 character set (VT220).
 *   ESC * Ps - Set G2 character set (VT220).
 *   ESC + Ps - Set G3 character set (VT220).
 *   ESC - Ps - Set G1 character set (VT300).
 *   ESC . Ps - Set G2 character set (VT300).
 *   ESC / Ps - Set G3 character set (VT300).
 *
 * All other sequences are echoed to the terminal.
 */
hterm.VT.ESC['('] =
hterm.VT.ESC[')'] =
hterm.VT.ESC['*'] =
hterm.VT.ESC['+'] =
hterm.VT.ESC['-'] =
hterm.VT.ESC['.'] =
hterm.VT.ESC['/'] = function(parseState, code) {
  parseState.func = function(parseState) {
    var ch = parseState.consumeChar();
    if (ch == '\x1b') {
      parseState.resetParseFunction();
      parseState.func();
      return;
    }

    var map = this.characterMaps.getMap(ch);
    if (map !== undefined) {
      if (code == '(') {
        this.G0 = map;
      } else if (code == ')' || code == '-') {
        this.G1 = map;
      } else if (code == '*' || code == '.') {
        this.G2 = map;
      } else if (code == '+' || code == '/') {
        this.G3 = map;
      }
    } else if (this.warnUnimplemented) {
      console.log('Invalid character set for "' + code + '": ' + ch);
    }

    parseState.resetParseFunction();
  };
};

/**
 * Back Index (DECBI).
 *
 * VT420 and up.  Not currently implemented.
 */
hterm.VT.ESC['6'] = hterm.VT.ignore;

/**
 * Save Cursor (DECSC).
 */
hterm.VT.ESC['7'] = function() {
  this.terminal.saveCursorAndState();
};

/**
 * Restore Cursor (DECRC).
 */
hterm.VT.ESC['8'] = function() {
  this.terminal.restoreCursorAndState();
};

/**
 * Forward Index (DECFI).
 *
 * VT210 and up.  Not currently implemented.
 */
hterm.VT.ESC['9'] = hterm.VT.ignore;

/**
 * Application keypad (DECKPAM).
 */
hterm.VT.ESC['='] = function() {
  this.terminal.keyboard.applicationKeypad = true;
};

/**
 * Normal keypad (DECKPNM).
 */
hterm.VT.ESC['>'] = function() {
  this.terminal.keyboard.applicationKeypad = false;
};

/**
 * Cursor to lower left corner of screen.
 *
 * Will not implement.
 *
 * This is only recognized by xterm when the hpLowerleftBugCompat resource is
 * set.
 */
hterm.VT.ESC['F'] = hterm.VT.ignore;

/**
 * Full Reset (RIS).
 */
hterm.VT.ESC['c'] = function() {
  this.terminal.reset();
};

/**
 * Memory lock/unlock.
 *
 * Will not implement.
 */
hterm.VT.ESC['l'] =
hterm.VT.ESC['m'] = hterm.VT.ignore;

/**
 * Lock Shift 2 (LS2)
 *
 * Invoke the G2 Character Set as GL.
 */
hterm.VT.ESC['n'] = function() {
  this.GL = 'G2';
};

/**
 * Lock Shift 3 (LS3)
 *
 * Invoke the G3 Character Set as GL.
 */
hterm.VT.ESC['o'] = function() {
  this.GL = 'G3';
};

/**
 * Lock Shift 2, Right (LS3R)
 *
 * Invoke the G3 Character Set as GR.
 */
hterm.VT.ESC['|'] = function() {
  this.GR = 'G3';
};

/**
 * Lock Shift 2, Right (LS2R)
 *
 * Invoke the G2 Character Set as GR.
 */
hterm.VT.ESC['}'] = function() {
  this.GR = 'G2';
};

/**
 * Lock Shift 1, Right (LS1R)
 *
 * Invoke the G1 Character Set as GR.
 */
hterm.VT.ESC['~'] = function() {
  this.GR = 'G1';
};

/**
 * Change icon name and window title.
 *
 * We only change the window title.
 */
hterm.VT.OSC['0'] = function(parseState) {
  this.terminal.setWindowTitle(parseState.args[0]);
};

/**
 * Change window title.
 */
hterm.VT.OSC['2'] = hterm.VT.OSC['0'];

/**
 * Set/read color palette.
 */
hterm.VT.OSC['4'] = function(parseState) {
  // Args come in as a single 'index1;rgb1 ... ;indexN;rgbN' string.
  // We split on the semicolon and iterate through the pairs.
  var args = parseState.args[0].split(';');

  var pairCount = parseInt(args.length / 2);
  var colorPalette = this.terminal.getTextAttributes().colorPalette;
  var responseArray = [];

  for (var pairNumber = 0; pairNumber < pairCount; ++pairNumber) {
    var colorIndex = parseInt(args[pairNumber * 2]);
    var colorValue = args[pairNumber * 2 + 1];

    if (colorIndex >= colorPalette.length)
      continue;

    if (colorValue == '?') {
      // '?' means we should report back the current color value.
      colorValue = lib.colors.rgbToX11(colorPalette[colorIndex]);
      if (colorValue)
        responseArray.push(colorIndex + ';' + colorValue);

      continue;
    }

    colorValue = lib.colors.x11ToCSS(colorValue);
    if (colorValue)
      colorPalette[colorIndex] = colorValue;
  }

  if (responseArray.length)
    this.terminal.io.sendString('\x1b]4;' + responseArray.join(';') + '\x07');
};

/**
 * Hyperlinks.
 *
 * The first argument is optional and colon separated:
 *   id=<id>
 * The second argument is the link itself.
 *
 * Calling with a non-blank URI starts it.  A blank URI stops it.
 *
 * https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda
 */
hterm.VT.OSC['8'] = function(parseState) {
  const args = parseState.args[0].split(';');
  let id = null;
  let uri = null;

  if (args.length != 2 || args[1].length == 0) {
    // Reset link.
  } else {
    // Pull out any colon separated parameters in the first argument.
    const params = args[0].split(':');
    id = '';
    params.forEach((param) => {
      const idx = param.indexOf('=');
      if (idx == -1)
        return;

      const key = param.slice(0, idx);
      const value = param.slice(idx + 1);
      switch (key) {
        case 'id':
          id = value;
          break;
        default:
          // Ignore unknown keys.
          break;
      }
    });

    // The URI is in the second argument.
    uri = args[1];
  }

  const attrs = this.terminal.getTextAttributes();
  attrs.uri = uri;
  attrs.uriId = id;
};

/**
 * iTerm2 growl notifications.
 */
hterm.VT.OSC['9'] = function(parseState) {
  // This just dumps the entire string as the message.
  hterm.notify({'body': parseState.args[0]});
};

/**
 * Change VT100 text foreground color.
 */
hterm.VT.OSC['10'] = function(parseState) {
  // Args come in as a single string, but extra args will chain to the following
  // OSC sequences.
  var args = parseState.args[0].split(';');
  if (!args)
    return;

  var colorArg;
  var colorX11 = lib.colors.x11ToCSS(args.shift());
  if (colorX11)
    this.terminal.setForegroundColor(colorX11);

  if (args.length > 0) {
    parseState.args[0] = args.join(';');
    hterm.VT.OSC['11'].apply(this, [parseState]);
  }
};

/**
 * Change VT100 text background color.
 */
hterm.VT.OSC['11'] = function(parseState) {
  // Args come in as a single string, but extra args will chain to the following
  // OSC sequences.
  var args = parseState.args[0].split(';');
  if (!args)
    return;

  var colorArg;
  var colorX11 = lib.colors.x11ToCSS(args.shift());
  if (colorX11)
    this.terminal.setBackgroundColor(colorX11);

  if (args.length > 0) {
    parseState.args[0] = args.join(';');
    hterm.VT.OSC['12'].apply(this, [parseState]);
  }
};

/**
 * Change text cursor color.
 */
hterm.VT.OSC['12'] = function(parseState) {
  // Args come in as a single string, but extra args will chain to the following
  // OSC sequences.
  var args = parseState.args[0].split(';');
  if (!args)
    return;

  var colorArg;
  var colorX11 = lib.colors.x11ToCSS(args.shift());
  if (colorX11)
    this.terminal.setCursorColor(colorX11);

  /* Note: If we support OSC 13+, we'd chain it here.
  if (args.length > 0) {
    parseState.args[0] = args.join(';');
    hterm.VT.OSC['13'].apply(this, [parseState]);
  }
  */
};

/**
 * Set the cursor shape.
 *
 * Parameter is expected to be in the form "CursorShape=number", where number is
 * one of:
 *
 *   0 - Block
 *   1 - I-Beam
 *   2 - Underline
 *
 * This is a bit of a de-facto standard supported by iTerm 2 and Konsole.  See
 * also: DECSCUSR.
 *
 * Invalid numbers will restore the cursor to the block shape.
 */
hterm.VT.OSC['50'] = function(parseState) {
  var args = parseState.args[0].match(/CursorShape=(.)/i);
  if (!args) {
    console.warn('Could not parse OSC 50 args: ' + parseState.args[0]);
    return;
  }

  switch (args[1]) {
    case '1':  // CursorShape=1: I-Beam.
      this.terminal.setCursorShape(hterm.Terminal.cursorShape.BEAM);
      break;

    case '2':  // CursorShape=2: Underline.
      this.terminal.setCursorShape(hterm.Terminal.cursorShape.UNDERLINE);
      break;

    default:  // CursorShape=0: Block.
      this.terminal.setCursorShape(hterm.Terminal.cursorShape.BLOCK);
  }
};

/**
 * Set/read system clipboard.
 *
 * Read is not implemented due to security considerations.  A remote app
 * that is able to both write and read to the clipboard could essentially
 * take over your session.
 *
 * The clipboard data will be decoded according to the 'receive-encoding'
 * preference.
 */
hterm.VT.OSC['52'] = function(parseState) {
  if (!this.enableClipboardWrite)
    return;

  // Args come in as a single 'clipboard;b64-data' string.  The clipboard
  // parameter is used to select which of the X clipboards to address.  Since
  // we're not integrating with X, we treat them all the same.
  var args = parseState.args[0].match(/^[cps01234567]*;(.*)/);
  if (!args)
    return;

  var data = window.atob(args[1]);
  if (data)
    this.terminal.copyStringToClipboard(this.decode(data));
};

/**
 * Reset color palette.
 */
hterm.VT.OSC['104'] = function(parseState) {
  const attrs = this.terminal.getTextAttributes();

  // If there are no args, we reset the entire palette.
  if (!parseState.args[0]) {
    attrs.resetColorPalette();
    return;
  }

  // Args come in as a single 'index1;index2;...;indexN' string.
  // Split on the semicolon and iterate through the colors.
  const args = parseState.args[0].split(';');
  args.forEach((c) => attrs.resetColor(c));
};

/**
 * Reset foreground color.
 */
hterm.VT.OSC['110'] = function(parseState) {
  this.terminal.setForegroundColor();
};

/**
 * Reset background color.
 */
hterm.VT.OSC['111'] = function(parseState) {
  this.terminal.setBackgroundColor();
};

/**
 * Reset text cursor color.
 */
hterm.VT.OSC['112'] = function(parseState) {
  this.terminal.setCursorColor();
};

/**
 * iTerm2 extended sequences.
 *
 * We only support image display atm.
 */
hterm.VT.OSC['1337'] = function(parseState) {
  // Args come in as a set of key value pairs followed by data.
  // File=name=<base64>;size=123;inline=1:<base64 data>
  let args = parseState.args[0].match(/^File=([^:]*):([\s\S]*)$/m);
  if (!args) {
    if (this.warnUnimplemented)
      console.log(`iTerm2 1337: unsupported sequence: ${args[1]}`);
    return;
  }

  const options = {
    name: '',
    size: 0,
    preserveAspectRatio: true,
    inline: false,
    width: 'auto',
    height: 'auto',
    align: 'left',
    uri: 'data:application/octet-stream;base64,' + args[2].replace(/[\n\r]+/gm, ''),
  };
  // Walk the "key=value;" sets.
  args[1].split(';').forEach((ele) => {
    const kv = ele.match(/^([^=]+)=(.*)$/m);
    if (!kv)
      return;

    // Sanitize values nicely.
    switch (kv[1]) {
      case 'name':
        try {
          options.name = window.atob(kv[2]);
        } catch (e) {}
        break;
      case 'size':
        try {
          options.size = parseInt(kv[2]);
        } catch (e) {}
        break;
      case 'width':
        options.width = kv[2];
        break;
      case 'height':
        options.height = kv[2];
        break;
      case 'preserveAspectRatio':
        options.preserveAspectRatio = !(kv[2] == '0');
        break;
      case 'inline':
        options.inline = !(kv[2] == '0');
        break;
      // hterm-specific keys.
      case 'align':
        options.align = kv[2];
        break;
      default:
        // Ignore unknown keys.  Don't want remote stuffing our JS env.
        break;
    }
  });

  // This is a bit of a hack.  If the buffer has data following the image, we
  // need to delay processing of it until after we've finished with the image.
  // Otherwise while we wait for the the image to load asynchronously, the new
  // text data will intermingle with the image.
  if (options.inline) {
    const io = this.terminal.io;
    const queued = parseState.peekRemainingBuf();
    parseState.advance(queued.length);
    this.terminal.displayImage(options);
    io.writeUTF8(queued);
  } else
    this.terminal.displayImage(options);
};

/**
 * URxvt perl modules.
 *
 * This is the escape system used by rxvt-unicode and its perl modules.
 * Obviously we don't support perl or custom modules, so we list a few common
 * ones that we find useful.
 *
 * Technically there is no format here, but most modules obey:
 * <module name>;<module args, usually ; delimited>
 */
hterm.VT.OSC['777'] = function(parseState) {
  var ary;
  var urxvtMod = parseState.args[0].split(';', 1)[0];

  switch (urxvtMod) {
    case 'notify':
      // Format:
      // notify;title;message
      var title, message;
      ary = parseState.args[0].match(/^[^;]+;([^;]*)(;([\s\S]*))?$/);
      if (ary) {
        title = ary[1];
        message = ary[3];
      }
      hterm.notify({'title': title, 'body': message});
      break;

    default:
      console.warn('Unknown urxvt module: ' + parseState.args[0]);
      break;
  }
};

/**
 * Insert (blank) characters (ICH).
 */
hterm.VT.CSI['@'] = function(parseState) {
  this.terminal.insertSpace(parseState.iarg(0, 1));
};

/**
 * Cursor Up (CUU).
 */
hterm.VT.CSI['A'] = function(parseState) {
  this.terminal.cursorUp(parseState.iarg(0, 1));
};

/**
 * Cursor Down (CUD).
 */
hterm.VT.CSI['B'] = function(parseState) {
  this.terminal.cursorDown(parseState.iarg(0, 1));
};

/**
 * Cursor Forward (CUF).
 */
hterm.VT.CSI['C'] = function(parseState) {
  this.terminal.cursorRight(parseState.iarg(0, 1));
};

/**
 * Cursor Backward (CUB).
 */
hterm.VT.CSI['D'] = function(parseState) {
  this.terminal.cursorLeft(parseState.iarg(0, 1));
};

/**
 * Cursor Next Line (CNL).
 *
 * This is like Cursor Down, except the cursor moves to the beginning of the
 * line as well.
 */
hterm.VT.CSI['E'] = function(parseState) {
  this.terminal.cursorDown(parseState.iarg(0, 1));
  this.terminal.setCursorColumn(0);
};

/**
 * Cursor Preceding Line (CPL).
 *
 * This is like Cursor Up, except the cursor moves to the beginning of the
 * line as well.
 */
hterm.VT.CSI['F'] = function(parseState) {
  this.terminal.cursorUp(parseState.iarg(0, 1));
  this.terminal.setCursorColumn(0);
};

/**
 * Cursor Horizontal Absolute (CHA).
 *
 * Xterm calls this Cursor Character Absolute.
 */
hterm.VT.CSI['G'] = function(parseState) {
  this.terminal.setCursorColumn(parseState.iarg(0, 1) - 1);
};

/**
 * Cursor Position (CUP).
 */
hterm.VT.CSI['H'] = function(parseState) {
  this.terminal.setCursorPosition(parseState.iarg(0, 1) - 1,
                                  parseState.iarg(1, 1) - 1);
};

/**
 * Cursor Forward Tabulation (CHT).
 */
hterm.VT.CSI['I'] = function(parseState) {
  var count = parseState.iarg(0, 1);
  count = lib.f.clamp(count, 1, this.terminal.screenSize.width);
  for (var i = 0; i < count; i++) {
    this.terminal.forwardTabStop();
  }
};

/**
 * Erase in Display (ED, DECSED).
 */
hterm.VT.CSI['J'] =
hterm.VT.CSI['?J'] = function(parseState, code) {
  var arg = parseState.args[0];

  if (!arg || arg == 0) {
    this.terminal.eraseBelow();
  } else if (arg == 1) {
    this.terminal.eraseAbove();
  } else if (arg == 2) {
    this.terminal.clear();
  } else if (arg == 3) {
    if (this.enableCsiJ3) {
      this.terminal.clearScrollback();
    }
  }
};

/**
 * Erase in line (EL, DECSEL).
 */
hterm.VT.CSI['K'] =
hterm.VT.CSI['?K'] = function(parseState, code) {
  var arg = parseState.args[0];

  if (!arg || arg == 0) {
    this.terminal.eraseToRight();
  } else if (arg == 1) {
    this.terminal.eraseToLeft();
  } else if (arg == 2) {
    this.terminal.eraseLine();
  }
};

/**
 * Insert Lines (IL).
 */
hterm.VT.CSI['L'] = function(parseState) {
  this.terminal.insertLines(parseState.iarg(0, 1));
};

/**
 * Delete Lines (DL).
 */
hterm.VT.CSI['M'] = function(parseState) {
  this.terminal.deleteLines(parseState.iarg(0, 1));
};

/**
 * Delete Characters (DCH).
 *
 * This command shifts the line contents left, starting at the cursor position.
 */
hterm.VT.CSI['P'] = function(parseState) {
  this.terminal.deleteChars(parseState.iarg(0, 1));
};

/**
 * Scroll Up (SU).
 */
hterm.VT.CSI['S'] = function(parseState) {
  this.terminal.vtScrollUp(parseState.iarg(0, 1));
};

/**
 * Scroll Down (SD).
 * Also 'Initiate highlight mouse tracking'.  Will not implement this part.
 */
hterm.VT.CSI['T'] = function(parseState) {
  if (parseState.args.length <= 1)
    this.terminal.vtScrollDown(parseState.iarg(0, 1));
};

/**
 * Reset one or more features of the title modes to the default value.
 *
 *   ESC [ > Ps T
 *
 * Normally, "reset" disables the feature. It is possible to disable the
 * ability to reset features by compiling a different default for the title
 * modes into xterm.
 *
 * Ps values:
 *   0 - Do not set window/icon labels using hexadecimal.
 *   1 - Do not query window/icon labels using hexadecimal.
 *   2 - Do not set window/icon labels using UTF-8.
 *   3 - Do not query window/icon labels using UTF-8.
 *
 * Will not implement.
 */
hterm.VT.CSI['>T'] = hterm.VT.ignore;

/**
 * Erase Characters (ECH).
 */
hterm.VT.CSI['X'] = function(parseState) {
  this.terminal.eraseToRight(parseState.iarg(0, 1));
};

/**
 * Cursor Backward Tabulation (CBT).
 */
hterm.VT.CSI['Z'] = function(parseState) {
  var count = parseState.iarg(0, 1);
  count = lib.f.clamp(count, 1, this.terminal.screenSize.width);
  for (var i = 0; i < count; i++) {
    this.terminal.backwardTabStop();
  }
};

/**
 * Character Position Absolute (HPA).
 *
 * Same as Cursor Horizontal Absolute (CHA).
 */
hterm.VT.CSI['`'] = hterm.VT.CSI['G'];

/**
 * Character Position Relative (HPR).
 */
hterm.VT.CSI['a'] = function(parseState) {
  this.terminal.setCursorColumn(this.terminal.getCursorColumn() +
                                parseState.iarg(0, 1));
};

/**
 * Repeat the preceding graphic character.
 *
 * Not currently implemented.
 */
hterm.VT.CSI['b'] = hterm.VT.ignore;

/**
 * Send Device Attributes (Primary DA).
 *
 * TODO(rginda): This is hardcoded to send back 'VT100 with Advanced Video
 * Option', but it may be more correct to send a VT220 response once
 * we fill out the 'Not currently implemented' parts.
 */
hterm.VT.CSI['c'] = function(parseState) {
  if (!parseState.args[0] || parseState.args[0] == 0) {
    this.terminal.io.sendString('\x1b[?1;2c');
  }
};

/**
 * Send Device Attributes (Secondary DA).
 *
 * TODO(rginda): This is hardcoded to send back 'VT100' but it may be more
 * correct to send a VT220 response once we fill out more 'Not currently
 * implemented' parts.
 */
hterm.VT.CSI['>c'] = function(parseState) {
  this.terminal.io.sendString('\x1b[>0;256;0c');
};

/**
 * Line Position Absolute (VPA).
 */
hterm.VT.CSI['d'] = function(parseState) {
  this.terminal.setAbsoluteCursorRow(parseState.iarg(0, 1) - 1);
};

/**
 * Horizontal and Vertical Position (HVP).
 *
 * Same as Cursor Position (CUP).
 */
hterm.VT.CSI['f'] = hterm.VT.CSI['H'];

/**
 * Tab Clear (TBC).
 */
hterm.VT.CSI['g'] = function(parseState) {
  if (!parseState.args[0] || parseState.args[0] == 0) {
    // Clear tab stop at cursor.
    this.terminal.clearTabStopAtCursor(false);
  } else if (parseState.args[0] == 3) {
    // Clear all tab stops.
    this.terminal.clearAllTabStops();
  }
};

/**
 * Set Mode (SM).
 */
hterm.VT.CSI['h'] = function(parseState) {
  for (var i = 0; i < parseState.args.length; i++) {
    this.setANSIMode(parseState.args[i], true);
  }
};

/**
 * DEC Private Mode Set (DECSET).
 */
hterm.VT.CSI['?h'] = function(parseState) {
  for (var i = 0; i < parseState.args.length; i++) {
    this.setDECMode(parseState.args[i], true);
  }
};

/**
 * Media Copy (MC).
 * Media Copy (MC, DEC Specific).
 *
 * These commands control the printer.  Will not implement.
 */
hterm.VT.CSI['i'] =
hterm.VT.CSI['?i'] = hterm.VT.ignore;

/**
 * Reset Mode (RM).
 */
hterm.VT.CSI['l'] = function(parseState) {
  for (var i = 0; i < parseState.args.length; i++) {
    this.setANSIMode(parseState.args[i], false);
  }
};

/**
 * DEC Private Mode Reset (DECRST).
 */
hterm.VT.CSI['?l'] = function(parseState) {
  for (var i = 0; i < parseState.args.length; i++) {
    this.setDECMode(parseState.args[i], false);
  }
};

/**
 * Parse extended SGR 38/48 sequences.
 *
 * This deals with the various ISO 8613-6 forms, and with legacy xterm forms
 * that are common in the wider application world.
 *
 * @param {hterm.VT.ParseState} parseState The current input state.
 * @param {number} i The argument in parseState to start processing.
 * @param {hterm.TextAttributes} attrs The current text attributes.
 * @return {Object} The skipCount member defines how many arguments to skip
 *     (i.e. how many were processed), and the color member is the color that
 *     was successfully processed, or undefined if not.
 */
hterm.VT.prototype.parseSgrExtendedColors = function(parseState, i, attrs) {
  let ary;
  let usedSubargs;

  if (parseState.argHasSubargs(i)) {
    // The ISO 8613-6 compliant form.
    // e.g. 38:[color choice]:[arg1]:[arg2]:...
    ary = parseState.args[i].split(':');
    ary.shift();  // Remove "38".
    usedSubargs = true;
  } else if (parseState.argHasSubargs(i + 1)) {
    // The xterm form which isn't ISO 8613-6 compliant.  Not many emulators
    // support this, and others actively do not want to.  We'll ignore it so
    // at least the rest of the stream works correctly.  e.g. 38;2:R:G:B
    // We return 0 here so we only skip the "38" ... we can't be confident the
    // next arg is actually supposed to be part of it vs a typo where the next
    // arg is legit.
    return {skipCount: 0};
  } else {
    // The xterm form which isn't ISO 8613-6 compliant, but many emulators
    // support, and many applications rely on.
    // e.g. 38;2;R;G;B
    ary = parseState.args.slice(i + 1);
    usedSubargs = false;
  }

  // Figure out which form to parse.
  switch (parseInt(ary[0])) {
    default:  // Unknown.
    case 0:  // Implementation defined.  We ignore it.
      return {skipCount: 0};

    case 1: {  // Transparent color.
      // Require ISO 8613-6 form.
      if (!usedSubargs)
        return {skipCount: 0};

      return {
        color: 'rgba(0, 0, 0, 0)',
        skipCount: 0,
      };
    }

    case 2: {  // RGB color.
      // Skip over the color space identifier, if it exists.
      let start;
      if (usedSubargs) {
        // The ISO 8613-6 compliant form:
        //   38:2:<color space id>:R:G:B[:...]
        // The xterm form isn't ISO 8613-6 compliant.
        //   38:2:R:G:B
        // Since the ISO 8613-6 form requires at least 5 arguments,
        // we can still support the xterm form unambiguously.
        if (ary.length == 4)
          start = 1;
        else
          start = 2;
      } else {
        // The legacy xterm form: 38;2;R;G;B
        start = 1;
      }

      // We need at least 3 args for RGB.  If we don't have them, assume this
      // sequence is corrupted, so don't eat anything more.
      // We ignore more than 3 args on purpose since ISO 8613-6 defines some,
      // and we don't care about them.
      if (ary.length < start + 3)
        return {skipCount: 0};

      const r = parseState.parseInt(ary[start + 0]);
      const g = parseState.parseInt(ary[start + 1]);
      const b = parseState.parseInt(ary[start + 2]);
      return {
        color: `rgb(${r}, ${g}, ${b})`,
        skipCount: usedSubargs ? 0 : 4,
      };
    }

    case 3: {  // CMY color.
      // No need to support xterm/legacy forms as xterm doesn't support CMY.
      if (!usedSubargs)
        return {skipCount: 0};

      // We need at least 4 args for CMY.  If we don't have them, assume
      // this sequence is corrupted.  We ignore the color space identifier,
      // tolerance, etc...
      if (ary.length < 4)
        return {skipCount: 0};

      // TODO: See CMYK below.
      const c = parseState.parseInt(ary[1]);
      const m = parseState.parseInt(ary[2]);
      const y = parseState.parseInt(ary[3]);
      return {skipCount: 0};
    }

    case 4: {  // CMYK color.
      // No need to support xterm/legacy forms as xterm doesn't support CMYK.
      if (!usedSubargs)
        return {skipCount: 0};

      // We need at least 5 args for CMYK.  If we don't have them, assume
      // this sequence is corrupted.  We ignore the color space identifier,
      // tolerance, etc...
      if (ary.length < 5)
        return {skipCount: 0};

      // TODO: Implement this.
      // Might wait until CSS4 is adopted for device-cmyk():
      // https://www.w3.org/TR/css-color-4/#cmyk-colors
      // Or normalize it to RGB ourselves:
      // https://www.w3.org/TR/css-color-4/#cmyk-rgb
      const c = parseState.parseInt(ary[1]);
      const m = parseState.parseInt(ary[2]);
      const y = parseState.parseInt(ary[3]);
      const k = parseState.parseInt(ary[4]);
      return {skipCount: 0};
    }

    case 5: {  // Color palette index.
      // If we're short on args, assume this sequence is corrupted, so don't
      // eat anything more.
      if (ary.length < 2)
        return {skipCount: 0};

      // Support 38:5:P (ISO 8613-6) and 38;5;P (xterm/legacy).
      // We also ignore extra args with 38:5:P:[...], but more for laziness.
      const ret = {
        skipCount: usedSubargs ? 0 : 2,
      };
      const color = parseState.parseInt(ary[1]);
      if (color < attrs.colorPalette.length)
        ret.color = color;
      return ret;
    }
  }
};

/**
 * Character Attributes (SGR).
 *
 * Iterate through the list of arguments, applying the attribute changes based
 * on the argument value...
 */
hterm.VT.CSI['m'] = function(parseState) {
  var attrs = this.terminal.getTextAttributes();

  if (!parseState.args.length) {
    attrs.reset();
    return;
  }

  for (var i = 0; i < parseState.args.length; i++) {
    // If this argument has subargs (i.e. it has args followed by colons),
    // the iarg logic will implicitly truncate that off for us.
    var arg = parseState.iarg(i, 0);

    if (arg < 30) {
      if (arg == 0) {  // Normal (default).
        attrs.reset();
      } else if (arg == 1) {  // Bold.
        attrs.bold = true;
      } else if (arg == 2) {  // Faint.
        attrs.faint = true;
      } else if (arg == 3) {  // Italic.
        attrs.italic = true;
      } else if (arg == 4) {  // Underline.
        if (parseState.argHasSubargs(i)) {
          const uarg = parseState.args[i].split(':')[1];
          if (uarg == 0)
            attrs.underline = false;
          else if (uarg == 1)
            attrs.underline = 'solid';
          else if (uarg == 2)
            attrs.underline = 'double';
          else if (uarg == 3)
            attrs.underline = 'wavy';
          else if (uarg == 4)
            attrs.underline = 'dotted';
          else if (uarg == 5)
            attrs.underline = 'dashed';
        } else {
          attrs.underline = 'solid';
        }
      } else if (arg == 5) {  // Blink.
        attrs.blink = true;
      } else if (arg == 7) {  // Inverse.
        attrs.inverse = true;
      } else if (arg == 8) {  // Invisible.
        attrs.invisible = true;
      } else if (arg == 9) {  // Crossed out.
        attrs.strikethrough = true;
      } else if (arg == 21) {  // Double underlined.
        attrs.underline = 'double';
      } else if (arg == 22) {  // Not bold & not faint.
        attrs.bold = false;
        attrs.faint = false;
      } else if (arg == 23) {  // Not italic.
        attrs.italic = false;
      } else if (arg == 24) {  // Not underlined.
        attrs.underline = false;
      } else if (arg == 25) {  // Not blink.
        attrs.blink = false;
      } else if (arg == 27) {  // Steady.
        attrs.inverse = false;
      } else if (arg == 28) {  // Visible.
        attrs.invisible = false;
      } else if (arg == 29) {  // Not crossed out.
        attrs.strikethrough = false;
      }

    } else if (arg < 50) {
      // Select fore/background color from bottom half of 16 color palette
      // or from the 256 color palette or alternative specify color in fully
      // qualified rgb(r, g, b) form.
      if (arg < 38) {
        attrs.foregroundSource = arg - 30;

      } else if (arg == 38) {
        const result = this.parseSgrExtendedColors(parseState, i, attrs);
        if (result.color !== undefined)
          attrs.foregroundSource = result.color;
        i += result.skipCount;

      } else if (arg == 39) {
        attrs.foregroundSource = attrs.SRC_DEFAULT;

      } else if (arg < 48) {
        attrs.backgroundSource = arg - 40;

      } else if (arg == 48) {
        const result = this.parseSgrExtendedColors(parseState, i, attrs);
        if (result.color !== undefined)
          attrs.backgroundSource = result.color;
        i += result.skipCount;

      } else {
        attrs.backgroundSource = attrs.SRC_DEFAULT;
      }

    } else if (arg == 58) {  // Underline coloring.
      const result = this.parseSgrExtendedColors(parseState, i, attrs);
      if (result.color !== undefined)
        attrs.underlineSource = result.color;
      i += result.skipCount;

    } else if (arg == 59) {  // Disable underline coloring.
      attrs.underlineSource = attrs.SRC_DEFAULT;

    } else if (arg >= 90 && arg <= 97) {
      attrs.foregroundSource = arg - 90 + 8;

    } else if (arg >= 100 && arg <= 107) {
      attrs.backgroundSource = arg - 100 + 8;
    }
  }

  attrs.setDefaults(this.terminal.getForegroundColor(),
                    this.terminal.getBackgroundColor());
};

// SGR calls can handle subargs.
hterm.VT.CSI['m'].supportsSubargs = true;

/**
 * Set xterm-specific keyboard modes.
 *
 * Will not implement.
 */
hterm.VT.CSI['>m'] = hterm.VT.ignore;

/**
 * Device Status Report (DSR, DEC Specific).
 *
 * 5 - Status Report. Result (OK) is CSI 0 n
 * 6 - Report Cursor Position (CPR) [row;column]. Result is CSI r ; c R
 */
hterm.VT.CSI['n'] = function(parseState) {
  if (parseState.args[0] == 5) {
    this.terminal.io.sendString('\x1b0n');
  } else if (parseState.args[0] == 6) {
    var row = this.terminal.getCursorRow() + 1;
    var col = this.terminal.getCursorColumn() + 1;
    this.terminal.io.sendString('\x1b[' + row + ';' + col + 'R');
  }
};

/**
 * Disable modifiers which may be enabled via CSI['>m'].
 *
 * Will not implement.
 */
hterm.VT.CSI['>n'] = hterm.VT.ignore;

/**
 * Device Status Report (DSR, DEC Specific).
 *
 * 6  - Report Cursor Position (CPR) [row;column] as CSI ? r ; c R
 * 15 - Report Printer status as CSI ? 1 0 n (ready) or
 *      CSI ? 1 1 n (not ready).
 * 25 - Report UDK status as CSI ? 2 0 n (unlocked) or CSI ? 2 1 n (locked).
 * 26 - Report Keyboard status as CSI ? 2 7 ; 1 ; 0 ; 0 n (North American).
 *      The last two parameters apply to VT400 & up, and denote keyboard ready
 *      and LK01 respectively.
 * 53 - Report Locator status as CSI ? 5 3 n Locator available, if compiled-in,
 *      or CSI ? 5 0 n No Locator, if not.
 */
hterm.VT.CSI['?n'] = function(parseState) {
  if (parseState.args[0] == 6) {
    var row = this.terminal.getCursorRow() + 1;
    var col = this.terminal.getCursorColumn() + 1;
    this.terminal.io.sendString('\x1b[' + row + ';' + col + 'R');
  } else if (parseState.args[0] == 15) {
    this.terminal.io.sendString('\x1b[?11n');
  } else if (parseState.args[0] == 25) {
    this.terminal.io.sendString('\x1b[?21n');
  } else if (parseState.args[0] == 26) {
    this.terminal.io.sendString('\x1b[?12;1;0;0n');
  } else if (parseState.args[0] == 53) {
    this.terminal.io.sendString('\x1b[?50n');
  }
};

/**
 * This is used by xterm to decide whether to hide the pointer cursor as the
 * user types.
 *
 * Valid values for the parameter:
 *   0 - Never hide the pointer.
 *   1 - Hide if the mouse tracking mode is not enabled.
 *   2 - Always hide the pointer.
 *
 * If no parameter is given, xterm uses the default, which is 1.
 *
 * Not currently implemented.
 */
hterm.VT.CSI['>p'] = hterm.VT.ignore;

/**
 * Soft terminal reset (DECSTR).
 */
hterm.VT.CSI['!p'] = function() {
  this.terminal.softReset();
};

/**
 * Request ANSI Mode (DECRQM).
 *
 * Not currently implemented.
 */
hterm.VT.CSI['$p'] = hterm.VT.ignore;
hterm.VT.CSI['?$p'] = hterm.VT.ignore;

/**
 * Set conformance level (DECSCL).
 *
 * Not currently implemented.
 */
hterm.VT.CSI['"p'] = hterm.VT.ignore;

/**
 * Load LEDs (DECLL).
 *
 * Not currently implemented.  Could be implemented as virtual LEDs overlaying
 * the terminal if anyone cares.
 */
hterm.VT.CSI['q'] = hterm.VT.ignore;

/**
 * Set cursor style (DECSCUSR, VT520).
 */
hterm.VT.CSI[' q'] = function(parseState) {
  var arg = parseState.args[0];

  if (arg == 0 || arg == 1) {
    this.terminal.setCursorShape(hterm.Terminal.cursorShape.BLOCK);
    this.terminal.setCursorBlink(true);
  } else if (arg == 2) {
    this.terminal.setCursorShape(hterm.Terminal.cursorShape.BLOCK);
    this.terminal.setCursorBlink(false);
  } else if (arg == 3) {
    this.terminal.setCursorShape(hterm.Terminal.cursorShape.UNDERLINE);
    this.terminal.setCursorBlink(true);
  } else if (arg == 4) {
    this.terminal.setCursorShape(hterm.Terminal.cursorShape.UNDERLINE);
    this.terminal.setCursorBlink(false);
  } else if (arg == 5) {
    this.terminal.setCursorShape(hterm.Terminal.cursorShape.BEAM);
    this.terminal.setCursorBlink(true);
  } else if (arg == 6) {
    this.terminal.setCursorShape(hterm.Terminal.cursorShape.BEAM);
    this.terminal.setCursorBlink(false);
  } else {
    console.warn('Unknown cursor style: ' + arg);
  }
};

/**
 * Select character protection attribute (DECSCA).
 *
 * Will not implement.
 */
hterm.VT.CSI['"q'] = hterm.VT.ignore;

/**
 * Set Scrolling Region (DECSTBM).
 */
hterm.VT.CSI['r'] = function(parseState) {
  var args = parseState.args;
  var scrollTop = args[0] ? parseInt(args[0], 10) -1 : null;
  var scrollBottom = args[1] ? parseInt(args[1], 10) - 1 : null;
  this.terminal.setVTScrollRegion(scrollTop, scrollBottom);
  this.terminal.setCursorPosition(0, 0);
};

/**
 * Restore DEC Private Mode Values.
 *
 * Will not implement.
 */
hterm.VT.CSI['?r'] = hterm.VT.ignore;

/**
 * Change Attributes in Rectangular Area (DECCARA)
 *
 * Will not implement.
 */
hterm.VT.CSI['$r'] = hterm.VT.ignore;

/**
 * Save cursor (ANSI.SYS)
 */
hterm.VT.CSI['s'] = function() {
  this.terminal.saveCursorAndState();
};

/**
 * Save DEC Private Mode Values.
 *
 * Will not implement.
 */
hterm.VT.CSI['?s'] = hterm.VT.ignore;

/**
 * Window manipulation (from dtterm, as well as extensions).
 *
 * Will not implement.
 */
hterm.VT.CSI['t'] = hterm.VT.ignore;

/**
 * Reverse Attributes in Rectangular Area (DECRARA).
 *
 * Will not implement.
 */
hterm.VT.CSI['$t'] = hterm.VT.ignore;

/**
 * Set one or more features of the title modes.
 *
 * Will not implement.
 */
hterm.VT.CSI['>t'] = hterm.VT.ignore;

/**
 * Set warning-bell volume (DECSWBV, VT520).
 *
 * Will not implement.
 */
hterm.VT.CSI[' t'] = hterm.VT.ignore;

/**
 * Restore cursor (ANSI.SYS).
 */
hterm.VT.CSI['u'] = function() {
  this.terminal.restoreCursorAndState();
};

/**
 * Set margin-bell volume (DECSMBV, VT520).
 *
 * Will not implement.
 */
hterm.VT.CSI[' u'] = hterm.VT.ignore;

/**
 * Copy Rectangular Area (DECCRA, VT400 and up).
 *
 * Will not implement.
 */
hterm.VT.CSI['$v'] = hterm.VT.ignore;

/**
 * Enable Filter Rectangle (DECEFR).
 *
 * Will not implement.
 */
hterm.VT.CSI['\'w'] = hterm.VT.ignore;

/**
 * Request Terminal Parameters (DECREQTPARM).
 *
 * Not currently implemented.
 */
hterm.VT.CSI['x'] = hterm.VT.ignore;

/**
 * Select Attribute Change Extent (DECSACE).
 *
 * Will not implement.
 */
hterm.VT.CSI['*x'] = hterm.VT.ignore;

/**
 * Fill Rectangular Area (DECFRA), VT420 and up.
 *
 * Will not implement.
 */
hterm.VT.CSI['$x'] = hterm.VT.ignore;

/**
 * vt_tiledata (as used by NAOhack and UnNetHack)
 * (see https://nethackwiki.com/wiki/Vt_tiledata for more info)
 *
 * Implemented as far as we care (start a glyph and end a glyph).
 */
hterm.VT.CSI['z'] = function(parseState) {
  if (parseState.args.length < 1)
    return;
  var arg = parseState.args[0];
  if (arg == 0) {
    // Start a glyph (one parameter, the glyph number).
    if (parseState.args.length < 2)
      return;
    this.terminal.getTextAttributes().tileData = parseState.args[1];
  } else if (arg == 1) {
    // End a glyph.
    this.terminal.getTextAttributes().tileData = null;
  }
};

/**
 * Enable Locator Reporting (DECELR).
 *
 * Not currently implemented.
 */
hterm.VT.CSI['\'z'] = hterm.VT.ignore;

/**
 * Erase Rectangular Area (DECERA), VT400 and up.
 *
 * Will not implement.
 */
hterm.VT.CSI['$z'] = hterm.VT.ignore;

/**
 * Select Locator Events (DECSLE).
 *
 * Not currently implemented.
 */
hterm.VT.CSI['\'{'] = hterm.VT.ignore;

/**
 * Request Locator Position (DECRQLP).
 *
 * Not currently implemented.
 */
hterm.VT.CSI['\'|'] = hterm.VT.ignore;

/**
 * Insert Columns (DECIC), VT420 and up.
 *
 * Will not implement.
 */
hterm.VT.CSI['\'}'] = hterm.VT.ignore;

/**
 * Delete P s Columns (DECDC), VT420 and up.
 *
 * Will not implement.
 */
hterm.VT.CSI['\'~'] = hterm.VT.ignore;
// SOURCE FILE: hterm/js/hterm_vt_character_map.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

lib.rtdep('lib.f');

/**
 * Character map object.
 *
 * Mapping from received to display character, used depending on the active
 * VT character set.
 *
 * GR maps are not currently supported.
 *
 * @param {string} description A human readable description of this map.
 * @param {Object} glmap The GL mapping from input to output characters.
 */
hterm.VT.CharacterMap = function(description, glmap) {
  /**
   * Short description for this character set, useful for debugging.
   */
  this.description = description;

  /**
   * The function to call to when this map is installed in GL.
   */
  this.GL = null;

  // Always keep an unmodified reference to the map.
  // This allows us to sanely reset back to the original state.
  this.glmapBase_ = glmap;

  // Now sync the internal state as needed.
  this.sync_();
};

/**
 * Internal helper for resyncing internal state.
 *
 * Used when the mappings change.
 *
 * @param {Object?} opt_glmap Additional mappings to overlay on top of the
 *     base mapping.
 */
hterm.VT.CharacterMap.prototype.sync_ = function(opt_glmap) {
  // If there are no maps, then reset the state back.
  if (!this.glmapBase_ && !opt_glmap) {
    this.GL = null;
    delete this.glmap_;
    delete this.glre_;
    return;
  }

  // Set the the GL mapping.  If we're given a custom mapping, then create a
  // new object to hold the merged map.  This way we can cleanly reset back.
  if (opt_glmap)
    this.glmap_ = Object.assign({}, this.glmapBase_, opt_glmap);
  else
    this.glmap_ = this.glmapBase_;

  var glchars = Object.keys(this.glmap_).map((key) =>
      '\\x' + lib.f.zpad(key.charCodeAt(0).toString(16)));
  this.glre_ = new RegExp('[' + glchars.join('') + ']', 'g');

  this.GL = (str) => str.replace(this.glre_, (ch) => this.glmap_[ch]);
};

/**
 * Reset map back to original mappings (discarding runtime updates).
 *
 * Specifically, any calls to setOverrides will be discarded.
 */
hterm.VT.CharacterMap.prototype.reset = function() {
  // If we haven't been given a custom mapping, then there's nothing to reset.
  if (this.glmap_ !== this.glmapBase_)
    this.sync_();
};

/**
 * Merge custom changes to this map.
 *
 * The input map need not duplicate the existing mappings as it is merged with
 * the existing base map (what was created with).  Subsequent calls to this
 * will throw away previous override settings.
 *
 * @param {Object} glmap The custom map to override existing mappings.
 */
hterm.VT.CharacterMap.prototype.setOverrides = function(glmap) {
  this.sync_(glmap);
};

/**
 * Return a copy of this mapping.
 *
 * @return {hterm.VT.CharacterMap} A new hterm.VT.CharacterMap instance.
 */
hterm.VT.CharacterMap.prototype.clone = function() {
  var map = new hterm.VT.CharacterMap(this.description, this.glmapBase_);
  if (this.glmap_ !== this.glmapBase_)
    map.setOverrides(this.glmap_);
  return map;
};

/**
 * Table of character maps.
 */
hterm.VT.CharacterMaps = function() {
  this.maps_ = hterm.VT.CharacterMaps.DefaultMaps;

  // Always keep an unmodified reference to the map.
  // This allows us to sanely reset back to the original state.
  this.mapsBase_ = this.maps_;
};

/**
 * Look up a previously registered map.
 *
 * @param {String} name The name of the map to lookup.
 * @return {hterm.VT.CharacterMap} The map, if it's been registered.
 */
hterm.VT.CharacterMaps.prototype.getMap = function(name) {
  if (this.maps_.hasOwnProperty(name))
    return this.maps_[name];
  else
    return undefined;
};

/**
 * Register a new map.
 *
 * Any previously registered maps by this name will be discarded.
 *
 * @param {String} name The name of the map.
 * @param {hterm.VT.CharacterMap} map The map to register.
 */
hterm.VT.CharacterMaps.prototype.addMap = function(name, map) {
  if (this.maps_ === this.mapsBase_)
    this.maps_ = Object.assign({}, this.mapsBase_);
  this.maps_[name] = map;
};

/**
 * Reset the table and all its maps back to original state.
 */
hterm.VT.CharacterMaps.prototype.reset = function() {
  if (this.maps_ !== hterm.VT.CharacterMaps.DefaultMaps)
    this.maps_ = hterm.VT.CharacterMaps.DefaultMaps;
};

/**
 * Merge custom changes to this table.
 *
 * @param {Object} maps A set of hterm.VT.CharacterMap objects.
 */
hterm.VT.CharacterMaps.prototype.setOverrides = function(maps) {
  if (this.maps_ === this.mapsBase_)
    this.maps_ = Object.assign({}, this.mapsBase_);

  for (var name in maps) {
    var map = this.getMap(name);
    if (map !== undefined) {
      this.maps_[name] = map.clone();
      this.maps_[name].setOverrides(maps[name]);
    } else
      this.addMap(name, new hterm.VT.CharacterMap('user ' + name, maps[name]));
  }
};

/**
 * The default set of supported character maps.
 */
hterm.VT.CharacterMaps.DefaultMaps = {};

/**
 * VT100 Graphic character map.
 * http://vt100.net/docs/vt220-rm/table2-4.html
 */
hterm.VT.CharacterMaps.DefaultMaps['0'] = new hterm.VT.CharacterMap(
    'graphic', {
      '\x60':'\u25c6',  // ` -> diamond
      '\x61':'\u2592',  // a -> grey-box
      '\x62':'\u2409',  // b -> h/t
      '\x63':'\u240c',  // c -> f/f
      '\x64':'\u240d',  // d -> c/r
      '\x65':'\u240a',  // e -> l/f
      '\x66':'\u00b0',  // f -> degree
      '\x67':'\u00b1',  // g -> +/-
      '\x68':'\u2424',  // h -> n/l
      '\x69':'\u240b',  // i -> v/t
      '\x6a':'\u2518',  // j -> bottom-right
      '\x6b':'\u2510',  // k -> top-right
      '\x6c':'\u250c',  // l -> top-left
      '\x6d':'\u2514',  // m -> bottom-left
      '\x6e':'\u253c',  // n -> line-cross
      '\x6f':'\u23ba',  // o -> scan1
      '\x70':'\u23bb',  // p -> scan3
      '\x71':'\u2500',  // q -> scan5
      '\x72':'\u23bc',  // r -> scan7
      '\x73':'\u23bd',  // s -> scan9
      '\x74':'\u251c',  // t -> left-tee
      '\x75':'\u2524',  // u -> right-tee
      '\x76':'\u2534',  // v -> bottom-tee
      '\x77':'\u252c',  // w -> top-tee
      '\x78':'\u2502',  // x -> vertical-line
      '\x79':'\u2264',  // y -> less-equal
      '\x7a':'\u2265',  // z -> greater-equal
      '\x7b':'\u03c0',  // { -> pi
      '\x7c':'\u2260',  // | -> not-equal
      '\x7d':'\u00a3',  // } -> british-pound
      '\x7e':'\u00b7',  // ~ -> dot
    });

/**
 * British character map.
 * http://vt100.net/docs/vt220-rm/table2-5.html
 */
hterm.VT.CharacterMaps.DefaultMaps['A'] = new hterm.VT.CharacterMap(
    'british', {
      '\x23': '\u00a3',  // # -> british-pound
    });

/**
 * US ASCII map, no changes.
 */
hterm.VT.CharacterMaps.DefaultMaps['B'] = new hterm.VT.CharacterMap(
    'us', null);

/**
 * Dutch character map.
 * http://vt100.net/docs/vt220-rm/table2-6.html
 */
hterm.VT.CharacterMaps.DefaultMaps['4'] = new hterm.VT.CharacterMap(
    'dutch', {
      '\x23': '\u00a3',  // # -> british-pound

      '\x40': '\u00be',  // @ -> 3/4

      '\x5b': '\u0132',  // [ -> 'ij' ligature (xterm goes with \u00ff?)
      '\x5c': '\u00bd',  // \ -> 1/2
      '\x5d': '\u007c',  // ] -> vertical bar

      '\x7b': '\u00a8',  // { -> two dots
      '\x7c': '\u0066',  // | -> f
      '\x7d': '\u00bc',  // } -> 1/4
      '\x7e': '\u00b4',  // ~ -> acute
    });

/**
 * Finnish character map.
 * http://vt100.net/docs/vt220-rm/table2-7.html
 */
hterm.VT.CharacterMaps.DefaultMaps['C'] =
hterm.VT.CharacterMaps.DefaultMaps['5'] = new hterm.VT.CharacterMap(
    'finnish', {
      '\x5b': '\u00c4',  // [ -> 'A' umlaut
      '\x5c': '\u00d6',  // \ -> 'O' umlaut
      '\x5d': '\u00c5',  // ] -> 'A' ring
      '\x5e': '\u00dc',  // ~ -> 'u' umlaut

      '\x60': '\u00e9',  // ` -> 'e' acute

      '\x7b': '\u00e4',  // { -> 'a' umlaut
      '\x7c': '\u00f6',  // | -> 'o' umlaut
      '\x7d': '\u00e5',  // } -> 'a' ring
      '\x7e': '\u00fc',  // ~ -> 'u' umlaut
    });

/**
 * French character map.
 * http://vt100.net/docs/vt220-rm/table2-8.html
 */
hterm.VT.CharacterMaps.DefaultMaps['R'] = new hterm.VT.CharacterMap(
    'french', {
      '\x23': '\u00a3',  // # -> british-pound

      '\x40': '\u00e0',  // @ -> 'a' grave

      '\x5b': '\u00b0',  // [ -> ring
      '\x5c': '\u00e7',  // \ -> 'c' cedilla
      '\x5d': '\u00a7',  // ] -> section symbol (double s)

      '\x7b': '\u00e9',  // { -> 'e' acute
      '\x7c': '\u00f9',  // | -> 'u' grave
      '\x7d': '\u00e8',  // } -> 'e' grave
      '\x7e': '\u00a8',  // ~ -> umlaut
    });

/**
 * French Canadian character map.
 * http://vt100.net/docs/vt220-rm/table2-9.html
 */
hterm.VT.CharacterMaps.DefaultMaps['Q'] = new hterm.VT.CharacterMap(
    'french canadian', {
      '\x40': '\u00e0',  // @ -> 'a' grave

      '\x5b': '\u00e2',  // [ -> 'a' circumflex
      '\x5c': '\u00e7',  // \ -> 'c' cedilla
      '\x5d': '\u00ea',  // ] -> 'e' circumflex
      '\x5e': '\u00ee',  // ^ -> 'i' circumflex

      '\x60': '\u00f4',  // ` -> 'o' circumflex

      '\x7b': '\u00e9',  // { -> 'e' acute
      '\x7c': '\u00f9',  // | -> 'u' grave
      '\x7d': '\u00e8',  // } -> 'e' grave
      '\x7e': '\u00fb',  // ~ -> 'u' circumflex
    });

/**
 * German character map.
 * http://vt100.net/docs/vt220-rm/table2-10.html
 */
hterm.VT.CharacterMaps.DefaultMaps['K'] = new hterm.VT.CharacterMap(
    'german', {
      '\x40': '\u00a7',  // @ -> section symbol (double s)

      '\x5b': '\u00c4',  // [ -> 'A' umlaut
      '\x5c': '\u00d6',  // \ -> 'O' umlaut
      '\x5d': '\u00dc',  // ] -> 'U' umlaut

      '\x7b': '\u00e4',  // { -> 'a' umlaut
      '\x7c': '\u00f6',  // | -> 'o' umlaut
      '\x7d': '\u00fc',  // } -> 'u' umlaut
      '\x7e': '\u00df',  // ~ -> eszett
    });

/**
 * Italian character map.
 * http://vt100.net/docs/vt220-rm/table2-11.html
 */
hterm.VT.CharacterMaps.DefaultMaps['Y'] = new hterm.VT.CharacterMap(
    'italian', {
      '\x23': '\u00a3',  // # -> british-pound

      '\x40': '\u00a7',  // @ -> section symbol (double s)

      '\x5b': '\u00b0',  // [ -> ring
      '\x5c': '\u00e7',  // \ -> 'c' cedilla
      '\x5d': '\u00e9',  // ] -> 'e' acute

      '\x60': '\u00f9',  // ` -> 'u' grave

      '\x7b': '\u00e0',  // { -> 'a' grave
      '\x7c': '\u00f2',  // | -> 'o' grave
      '\x7d': '\u00e8',  // } -> 'e' grave
      '\x7e': '\u00ec',  // ~ -> 'i' grave
    });

/**
 * Norwegian/Danish character map.
 * http://vt100.net/docs/vt220-rm/table2-12.html
 */
hterm.VT.CharacterMaps.DefaultMaps['E'] =
hterm.VT.CharacterMaps.DefaultMaps['6'] = new hterm.VT.CharacterMap(
    'norwegian/danish', {
      '\x40': '\u00c4',  // @ -> 'A' umlaut

      '\x5b': '\u00c6',  // [ -> 'AE' ligature
      '\x5c': '\u00d8',  // \ -> 'O' stroke
      '\x5d': '\u00c5',  // ] -> 'A' ring
      '\x5e': '\u00dc',  // ^ -> 'U' umlaut

      '\x60': '\u00e4',  // ` -> 'a' umlaut

      '\x7b': '\u00e6',  // { -> 'ae' ligature
      '\x7c': '\u00f8',  // | -> 'o' stroke
      '\x7d': '\u00e5',  // } -> 'a' ring
      '\x7e': '\u00fc',  // ~ -> 'u' umlaut
    });

/**
 * Spanish character map.
 * http://vt100.net/docs/vt220-rm/table2-13.html
 */
hterm.VT.CharacterMaps.DefaultMaps['Z'] = new hterm.VT.CharacterMap(
    'spanish', {
      '\x23': '\u00a3',  // # -> british-pound

      '\x40': '\u00a7',  // @ -> section symbol (double s)

      '\x5b': '\u00a1',  // [ -> '!' inverted
      '\x5c': '\u00d1',  // \ -> 'N' tilde
      '\x5d': '\u00bf',  // ] -> '?' inverted

      '\x7b': '\u00b0',  // { -> ring
      '\x7c': '\u00f1',  // | -> 'n' tilde
      '\x7d': '\u00e7',  // } -> 'c' cedilla
    });

/**
 * Swedish character map.
 * http://vt100.net/docs/vt220-rm/table2-14.html
 */
hterm.VT.CharacterMaps.DefaultMaps['7'] =
hterm.VT.CharacterMaps.DefaultMaps['H'] = new hterm.VT.CharacterMap(
    'swedish', {
      '\x40': '\u00c9',  // @ -> 'E' acute

      '\x5b': '\u00c4',  // [ -> 'A' umlaut
      '\x5c': '\u00d6',  // \ -> 'O' umlaut
      '\x5d': '\u00c5',  // ] -> 'A' ring
      '\x5e': '\u00dc',  // ^ -> 'U' umlaut

      '\x60': '\u00e9',  // ` -> 'e' acute

      '\x7b': '\u00e4',  // { -> 'a' umlaut
      '\x7c': '\u00f6',  // | -> 'o' umlaut
      '\x7d': '\u00e5',  // } -> 'a' ring
      '\x7e': '\u00fc',  // ~ -> 'u' umlaut
    });

/**
 * Swiss character map.
 * http://vt100.net/docs/vt220-rm/table2-15.html
 */
hterm.VT.CharacterMaps.DefaultMaps['='] = new hterm.VT.CharacterMap(
    'swiss', {
      '\x23': '\u00f9',  // # -> 'u' grave

      '\x40': '\u00e0',  // @ -> 'a' grave

      '\x5b': '\u00e9',  // [ -> 'e' acute
      '\x5c': '\u00e7',  // \ -> 'c' cedilla
      '\x5d': '\u00ea',  // ] -> 'e' circumflex
      '\x5e': '\u00ee',  // ^ -> 'i' circumflex
      '\x5f': '\u00e8',  // _ -> 'e' grave

      '\x60': '\u00f4',  // ` -> 'o' circumflex

      '\x7b': '\u00e4',  // { -> 'a' umlaut
      '\x7c': '\u00f6',  // | -> 'o' umlaut
      '\x7d': '\u00fc',  // } -> 'u' umlaut
      '\x7e': '\u00fb',  // ~ -> 'u' circumflex
    });
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);

lib.resource.add('hterm/concat/date', 'text/plain',
'Wed, 09 Jan 2019 03:18:44 +0000'
);

lib.resource.add('hterm/changelog/version', 'text/plain',
'1.83'
);

lib.resource.add('hterm/changelog/date', 'text/plain',
'2018-12-02, Minor improvements.'
);

lib.resource.add('hterm/git/HEAD', 'text/plain',
'51a7383c85c090ca3139e965703c44673205571c'
);

// SOURCE FILE: libdot/js/lib_codec.js
// Copyright 2018 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

lib.codec = {};

/**
 * Join an array of code units to a string.
 *
 * The code units must not be larger than 65535.  The individual code units may
 * be for UTF-8 or UTF-16 -- it doesn't matter since UTF-16 can handle all UTF-8
 * code units.
 *
 * The input array type may be an Array or a typed Array (e.g. Uint8Array).
 *
 * @param {Array<number>} array The code units to generate for the string.
 * @return {string} A UTF-16 encoded string.
 */
lib.codec.codeUnitArrayToString = function(array) {
  // String concat is faster than Array.join.
  let ret = '';
  for (let i = 0; i < array.length; ++i) {
    ret += String.fromCharCode(array[i]);
  }
  return ret;
};

/**
 * Create an array of code units from a UTF-16 encoded string.
 *
 * @param {string} str The string to extract code units from.
 * @param {type=} type The type of the return value.
 * @return {Array<number>} The array of code units.
 */
lib.codec.stringToCodeUnitArray = function(str, type=Array) {
  // Indexing string directly is faster than Array.map.
  const ret = new type(str.length);
  for (let i = 0; i < str.length; ++i) {
    ret[i] = str.charCodeAt(i);
  }
  return ret;
};
// SOURCE FILE: libdot/js/lib_credential_cache.js
// Copyright 2018 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

/**
 * @fileoverview A general-purpose cache for user credentials in the form of
 * a Uint8Array.
 */

/**
 * A general-purpose cache for user credentials in the form of a Uint8Array.
 *
 * The data in the cache is encrypted at rest using a random Web Crypto AES-CBC
 * key.
 *
 * Security considerations:
 *
 * - The cache is only used by the current Secure Shell window and
 * cleared when the screen locks.
 * - Data in the cache is encrypted using a random Web Crypto AES-CBC
 * key configured to be non-extractable and a randomly generated IV for
 * every encryption operation.
 * - Since the Web Crypto spec does not require non-extractable keys to be
 * kept in a secure hardware element or protected memory, a leak of
 * memory contents should realistically be considered equivalent to a
 * full compromise.
 * - Malicious servers can abuse the caching behavior for e.g. user passwords
 * and smart card PINs if the user has agent forwarding enabled.
 *
 * @constructor
 */
lib.CredentialCache = function() {
  /**
   * The underlying cache. Keys are strings and the cache entries consist of the
   * encrypted data and the initialization vector (IV) used for the AES
   * encryption in CBC mode.
   *
   * @member {?Object<!string, {encryptedData: !Uint8Array, iv: !Uint8Array}>>}
   * @private
   */
  this.cache_ = null;

  /**
   * The Web Crypto API AES-CBC CryptoKey that has been used to encrypt the data
   * in the cache. The key is randomly generated during initialization or after
   * the cache has been cleared.
   *
   * @member {?CryptoKey}
   * @private
   */
  this.cryptoKey_ = null;

  /**
   * Set to true if caching is enabled; false if caching is disabled and null if
   * the user has not yet made a decision.
   *
   * @member {?boolean}
   * @private
   */
  this.enabled_ = null;

  // Clear the cache on screen lock.
  if (window.chrome && chrome.idle) {
    chrome.idle.onStateChanged.addListener((state) => {
      if (state === 'locked') {
        this.clear_();
      }
    });
  }
};

/**
 * Initialize the cache and generate a new, non-extractable encryption key.
 *
 * @returns {!Promise.<void>}
 * @private
 */
lib.CredentialCache.prototype.init_ = async function() {
  this.cache_ = {};
  this.cryptoKey_ = await window.crypto.subtle.generateKey(
      {name: 'AES-CBC', length: 128}, false, ['encrypt', 'decrypt']);
};

/**
 * Clear the cache and delete the reference to the encryption key.
 *
 * @private
 */
lib.CredentialCache.prototype.clear_ = function() {
  this.cache_ = null;
  this.cryptoKey_ = null;
  this.enabled_ = null;
};

/**
 * Retrieve the cached data for the given key string.
 *
 * Note: The data bytes in the returned Uint8Array should be overwritten after
 * use.
 *
 * Note: In order to ensure consistency, upon successful retrieval the cached
 * data is deleted and should be added again after its validity has been
 * verified.
 *
 * @param {!string} key The key to which the corresponding data should be
 *     looked up.
 * @returns {Promise.<?Uint8Array>} The data bytes if the key is present in the
 *     cache; null otherwise.
 */
lib.CredentialCache.prototype.retrieve = async function(key) {
  if (!this.cache_) {
    await this.init_();
  }
  if (key in this.cache_) {
    const {encryptedData, iv} = this.cache_[key];
    // Remove cache entry to be added again only if data verification succeeds.
    delete this.cache_[key];
    return new Uint8Array(await window.crypto.subtle.decrypt(
        {name: 'AES-CBC', iv}, this.cryptoKey_, encryptedData));
  }
  return null;
};

/**
 * Store the data in the cache under the given key.
 *
 * Note: The provided data array is overwritten with zeroes after the data has
 * been added to the cache.
 *
 * @param {!string} key The key under which the data should be stored in the
 *     cache.
 * @param {!Uint8Array} data The data bytes to be stored.
 * @returns {Promise.<void>}
 */
lib.CredentialCache.prototype.store = async function(key, data) {
  if (!this.cache_) {
    await this.init_();
  }
  // AES-CBC requires a new, cryptographically random IV for every operation.
  const iv = window.crypto.getRandomValues(new Uint8Array(16));
  const encryptedData = await window.crypto.subtle.encrypt(
      {name: 'AES-CBC', iv}, this.cryptoKey_, data.buffer);
  data.fill(0);
  this.cache_[key] = {encryptedData, iv};
};

/**
 * Check whether caching is enabled.
 *
 * @returns {?boolean} True if the user enabled caching; false if the user
 *     disabled caching; null if the user has not made a decision yet.
 */
lib.CredentialCache.prototype.isEnabled = function() {
  return this.enabled_;
};

/**
 * Enable or disable caching.
 *
 * Note: Caching can only be enabled or disabled once.
 *
 * @param {!boolean} enable
 */
lib.CredentialCache.prototype.setEnabled = function(enable) {
  if (this.enabled_ === null) {
    this.enabled_ = enable;
  }
};
// SOURCE FILE: libdot/js/lib_event.js
// Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

lib.rtdep('lib.f');

/**
 * An event is a JavaScript function with addListener and removeListener
 * properties.
 *
 * When the endpoint function is called, the firstCallback will be invoked,
 * followed by all of the listeners in the order they were attached, then
 * the finalCallback.
 *
 * The returned function will have the list of callbacks, excluding
 * opt_firstCallback and opt_lastCallback, as its 'observers' property.
 *
 * @param {function(...)} opt_firstCallback The optional function to call
 *     before the observers.
 * @param {function(...)} opt_finalCallback The optional function to call
 *     after the observers.
 *
 * @return {function(...)} A function that, when called, invokes all callbacks
 *     with whatever arguments it was passed.
 */
lib.Event = function(opt_firstCallback, opt_finalCallback) {
  var ep = function() {
    var args = Array.prototype.slice.call(arguments);

    var rv;
    if (opt_firstCallback)
      rv = opt_firstCallback.apply(null, args);

    if (rv === false)
      return;

    ep.observers.forEach((ary) => ary[0].apply(ary[1], args));

    if (opt_finalCallback)
      opt_finalCallback.apply(null, args);
  };

  /**
   * Add a callback function.
   *
   * @param {function(...)} callback The function to call back.
   * @param {Object} opt_obj The optional |this| object to apply the function
   *     to.  Use this rather than bind when you plan on removing the listener
   *     later, so that you don't have to save the bound-function somewhere.
   */
  ep.addListener = function(callback, opt_obj) {
    if (!callback) {
      console.error('Missing param: callback');
      console.log(lib.f.getStack());
    }

    ep.observers.push([callback, opt_obj]);
  };

  /**
   * Remove a callback function.
   */
  ep.removeListener = function(callback, opt_obj) {
    for (var i = 0; i < ep.observers.length; i++) {
      if (ep.observers[i][0] == callback && ep.observers[i][1] == opt_obj) {
        ep.observers.splice(i, 1);
        break;
      }
    }
  };

  ep.observers = [];


  return ep;
};
// SOURCE FILE: libdot/js/lib_fs.js
// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

lib.rtdep('lib.f.getStack');

/**
 * HTML5 FileSystem related utility functions.
 */
lib.fs = {};

/**
 * Returns a function that console.log()'s its arguments, prefixed by |msg|.
 *
 * This is a useful utility function when working with the FileSystem's many
 * async, callbacktastic methods.
 *
 * * Use it when you don't think you care about a callback.  If it ever gets
 *   called, you get a log message that includes any parameters passed to the
 *   callback.
 *
 * * Use it as your "log a messages, then invoke this other method" pattern.
 *   Great for debugging or times when you want to log a message before
 *   invoking a callback passed in to your method.
 *
 * @param {string} msg The message prefix to use in the log.
 * @param {function(*)} opt_callback A function to invoke after logging.
 */
lib.fs.log = function(msg, opt_callback) {
  return function() {
    var ary = Array.apply(null, arguments);
    console.log(msg + ': ' + ary.join(', '));
    if (opt_callback)
      opt_callback.call(null, arguments);
  };
};

/**
 * Returns a function that console.error()'s its arguments, prefixed by |msg|.
 *
 * This is exactly like fs.log(), except the message in the JS console will
 * be styled as an error.  See fs.log() for some use cases.
 *
 * @param {string} msg The message prefix to use in the log.
 * @param {function(*)} opt_callback A function to invoke after logging.
 */
lib.fs.err = function(msg, opt_callback) {
  return function() {
    var ary = Array.apply(null, arguments);
    console.error(msg + ': ' + ary.join(', '), lib.f.getStack());
    if (opt_callback)
      opt_callback.call(null, arguments);
  };
};

/**
 * Overwrite a file on an HTML5 filesystem.
 *
 * Replace the contents of a file with the string provided.  If the file
 * doesn't exist it is created.  If it does, it is removed and re-created.
 *
 * @param {DirectoryEntry} root The directory to consider as the root of the
 *     path.
 * @param {string} path The path of the target file, relative to root.
 * @param {Blob|string} contents The new contents of the file.
 * @param {function()} onSuccess The function to invoke after success.
 * @param {function(DOMError)} opt_onError Optional function to invoke if the
 *     operation fails.
 */
lib.fs.overwriteFile = function(root, path, contents, onSuccess, opt_onError) {
  function onFileRemoved() {
    lib.fs.getOrCreateFile(root, path,
                          onFileFound,
                          lib.fs.log('Error creating: ' + path, opt_onError));
  }

  function onFileFound(fileEntry) {
    fileEntry.createWriter(onFileWriter,
                           lib.fs.log('Error creating writer for: ' + path,
                                      opt_onError));
  }

  function onFileWriter(writer) {
    writer.onwriteend = onSuccess;
    writer.onerror = lib.fs.log('Error writing to: ' + path, opt_onError);

    if (!(contents instanceof Blob)) {
      contents = new Blob([contents], {type: 'text/plain'});
    }

    writer.write(contents);
  }

  root.getFile(path, {create: false},
               function(fileEntry) {
                 fileEntry.remove(onFileRemoved, onFileRemoved);
               },
               onFileRemoved);
};

/**
 * Read a file on an HTML5 filesystem.
 *
 * @param {DirectoryEntry} root The directory to consider as the root of the
 *     path.
 * @param {string} path The path of the target file, relative to root.
 * @param {function(string)} onSuccess The function to invoke after
 *     success.
 * @param {function(DOMError)} opt_onError Optional function to invoke if the
 *     operation fails.
 */
lib.fs.readFile = function(root, path, onSuccess, opt_onError) {
  function onFileFound(fileEntry) {
    fileEntry.file(function(file) {
      const reader = new lib.fs.FileReader();
      reader.readAsText(file).then(onSuccess);
    }, opt_onError);
  }

  root.getFile(path, {create: false}, onFileFound, opt_onError);
};


/**
 * Remove a file from an HTML5 filesystem.
 *
 * @param {DirectoryEntry} root The directory to consider as the root of the
 *     path.
 * @param {string} path The path of the target file, relative to root.
 * @param {function(string)} opt_onSuccess Optional function to invoke after
 *     success.
 * @param {function(DOMError)} opt_onError Optional function to invoke if the
 *     operation fails.
 */
lib.fs.removeFile = function(root, path, opt_onSuccess, opt_onError) {
  root.getFile(
      path, {},
      function (f) {
        f.remove(lib.fs.log('Removed: ' + path, opt_onSuccess),
                 lib.fs.err('Error removing' + path, opt_onError));
      },
      lib.fs.log('Error finding: ' + path, opt_onError)
  );
};

/**
 * Build a list of all FileEntrys in an HTML5 filesystem.
 *
 * @param {DirectoryEntry} root The directory to consider as the root of the
 *     path.
 * @param {string} path The path of the target file, relative to root.
 * @param {function(Object)} onSuccess The function to invoke after
 *     success.
 * @param {function(DOMError)} opt_onError Optional function to invoke
 *     if the operation fails.
 */
lib.fs.readDirectory = function(root, path, onSuccess, opt_onError) {
  var entries = {};

  function onDirectoryFound(dirEntry) {
    var reader = dirEntry.createReader();
    reader.readEntries(function(results) {
        for (var i = 0; i < results.length; i++) {
          entries[results[i].name] = results[i];
        }

        if (true || !results.length) {
          onSuccess(entries);
          return;
        }
      }, opt_onError);
  }

  root.getDirectory(path, {create: false}, onDirectoryFound, opt_onError);
};

/**
 * Locate the file referred to by path, creating directories or the file
 * itself if necessary.
 *
 * @param {DirectoryEntry} root The directory to consider as the root of the
 *     path.
 * @param {string} path The path of the target file, relative to root.
 * @param {function(string)} onSuccess The function to invoke after
 *     success.
 * @param {function(DOMError)} opt_onError Optional function to invoke if the
 *     operation fails.
 */
lib.fs.getOrCreateFile = function(root, path, onSuccess, opt_onError) {
  var dirname = null;
  var basename = null;

  function onDirFound(dirEntry) {
    dirEntry.getFile(basename, { create: true }, onSuccess, opt_onError);
  }

  var i = path.lastIndexOf('/');
  if (i > -1) {
    dirname = path.substr(0, i);
    basename = path.substr(i + 1);
  } else {
    basename = path;
  }

  if (!dirname) {
    onDirFound(root);
    return;
  }

  lib.fs.getOrCreateDirectory(root, dirname, onDirFound, opt_onError);
};

/**
 * Locate the directory referred to by path, creating directories along the
 * way.
 *
 * @param {DirectoryEntry} root The directory to consider as the root of the
 *     path.
 * @param {string} path The path of the target file, relative to root.
 * @param {function(string)} onSuccess The function to invoke after success.
 * @param {function(DOMError)} opt_onError Optional function to invoke if the
 *     operation fails.
 */
lib.fs.getOrCreateDirectory = function(root, path, onSuccess, opt_onError) {
  var names = path.split('/');

  function getOrCreateNextName(dir) {
    if (!names.length)
      return onSuccess(dir);

    var name = names.shift();

    if (!name || name == '.') {
      getOrCreateNextName(dir);
    } else {
      dir.getDirectory(name, { create: true }, getOrCreateNextName,
                       opt_onError);
    }
  }

  getOrCreateNextName(root);
};

/**
 * A Promise API around the FileReader API.
 *
 * The FileReader API is old, so wrap its callbacks with a Promise.
 */
lib.fs.FileReader = function() {
};

/**
 * Internal helper for wrapping all the readAsXxx funcs.
 *
 * @param {Blob} blob The blob of data to read.
 * @param {string} method The specific readAsXxx function to call.
 * @param {Promise} A promise to resolve when reading finishes or fails.
 */
lib.fs.FileReader.prototype.readAs_ = function(blob, method) {
  return new Promise((resolve, reject) => {
    const reader = new FileReader();
    reader.onload = () => resolve(reader.result);
    reader.onabort = reader.onerror = () => reject(reader);
    reader[method](blob);
  });
};

/**
 * Wrapper around FileReader.readAsArrayBuffer.
 *
 * @param {Blob} blob The blob of data to read.
 * @param {Promise} A promise to resolve when reading finishes or fails.
 */
lib.fs.FileReader.prototype.readAsArrayBuffer = function(blob) {
  return this.readAs_(blob, 'readAsArrayBuffer');
};

/**
 * Wrapper around FileReader.readAsBinaryString.
 *
 * @param {Blob} blob The blob of data to read.
 * @param {Promise} A promise to resolve when reading finishes or fails.
 */
lib.fs.FileReader.prototype.readAsBinaryString = function(blob) {
  return this.readAs_(blob, 'readAsBinaryString');
};

/**
 * Wrapper around FileReader.readAsDataURL.
 *
 * @param {Blob} blob The blob of data to read.
 * @param {Promise} A promise to resolve when reading finishes or fails.
 */
lib.fs.FileReader.prototype.readAsDataURL = function(blob) {
  return this.readAs_(blob, 'readAsDataURL');
};

/**
 * Wrapper around FileReader.readAsText.
 *
 * @param {Blob} blob The blob of data to read.
 * @param {Promise} A promise to resolve when reading finishes or fails.
 */
lib.fs.FileReader.prototype.readAsText = function(blob) {
  return this.readAs_(blob, 'readAsText');
};
// SOURCE FILE: libdot/third_party/punycode/lib_punycode.js
// Copyright 2017 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Note: Don't modify this file between the ###AUTO### marks.  This is mostly
// taken unmodified from the upstream.  Use bin/update-punycode to update.

lib.punycode = {};

(function(exports) {

// ### AUTO-START ###

// This is v2.1.0 from https://github.com/bestiejs/punycode.js

/** Highest positive signed 32-bit float value */
const maxInt = 2147483647; // aka. 0x7FFFFFFF or 2^31-1

/** Bootstring parameters */
const base = 36;
const tMin = 1;
const tMax = 26;
const skew = 38;
const damp = 700;
const initialBias = 72;
const initialN = 128; // 0x80
const delimiter = '-'; // '\x2D'

/** Regular expressions */
const regexPunycode = /^xn--/;
const regexNonASCII = /[^\0-\x7E]/; // non-ASCII chars
const regexSeparators = /[\x2E\u3002\uFF0E\uFF61]/g; // RFC 3490 separators

/** Error messages */
const errors = {
	'overflow': 'Overflow: input needs wider integers to process',
	'not-basic': 'Illegal input >= 0x80 (not a basic code point)',
	'invalid-input': 'Invalid input'
};

/** Convenience shortcuts */
const baseMinusTMin = base - tMin;
const floor = Math.floor;
const stringFromCharCode = String.fromCharCode;

/*--------------------------------------------------------------------------*/

/**
 * A generic error utility function.
 * @private
 * @param {String} type The error type.
 * @returns {Error} Throws a `RangeError` with the applicable error message.
 */
function error(type) {
	throw new RangeError(errors[type]);
}

/**
 * A generic `Array#map` utility function.
 * @private
 * @param {Array} array The array to iterate over.
 * @param {Function} callback The function that gets called for every array
 * item.
 * @returns {Array} A new array of values returned by the callback function.
 */
function map(array, fn) {
	const result = [];
	let length = array.length;
	while (length--) {
		result[length] = fn(array[length]);
	}
	return result;
}

/**
 * A simple `Array#map`-like wrapper to work with domain name strings or email
 * addresses.
 * @private
 * @param {String} domain The domain name or email address.
 * @param {Function} callback The function that gets called for every
 * character.
 * @returns {Array} A new string of characters returned by the callback
 * function.
 */
function mapDomain(string, fn) {
	const parts = string.split('@');
	let result = '';
	if (parts.length > 1) {
		// In email addresses, only the domain name should be punycoded. Leave
		// the local part (i.e. everything up to `@`) intact.
		result = parts[0] + '@';
		string = parts[1];
	}
	// Avoid `split(regex)` for IE8 compatibility. See #17.
	string = string.replace(regexSeparators, '\x2E');
	const labels = string.split('.');
	const encoded = map(labels, fn).join('.');
	return result + encoded;
}

/**
 * Creates an array containing the numeric code points of each Unicode
 * character in the string. While JavaScript uses UCS-2 internally,
 * this function will convert a pair of surrogate halves (each of which
 * UCS-2 exposes as separate characters) into a single code point,
 * matching UTF-16.
 * @see `punycode.ucs2.encode`
 * @see <https://mathiasbynens.be/notes/javascript-encoding>
 * @memberOf punycode.ucs2
 * @name decode
 * @param {String} string The Unicode input string (UCS-2).
 * @returns {Array} The new array of code points.
 */
function ucs2decode(string) {
	const output = [];
	let counter = 0;
	const length = string.length;
	while (counter < length) {
		const value = string.charCodeAt(counter++);
		if (value >= 0xD800 && value <= 0xDBFF && counter < length) {
			// It's a high surrogate, and there is a next character.
			const extra = string.charCodeAt(counter++);
			if ((extra & 0xFC00) == 0xDC00) { // Low surrogate.
				output.push(((value & 0x3FF) << 10) + (extra & 0x3FF) + 0x10000);
			} else {
				// It's an unmatched surrogate; only append this code unit, in case the
				// next code unit is the high surrogate of a surrogate pair.
				output.push(value);
				counter--;
			}
		} else {
			output.push(value);
		}
	}
	return output;
}

/**
 * Creates a string based on an array of numeric code points.
 * @see `punycode.ucs2.decode`
 * @memberOf punycode.ucs2
 * @name encode
 * @param {Array} codePoints The array of numeric code points.
 * @returns {String} The new Unicode string (UCS-2).
 */
const ucs2encode = array => String.fromCodePoint(...array);

/**
 * Converts a basic code point into a digit/integer.
 * @see `digitToBasic()`
 * @private
 * @param {Number} codePoint The basic numeric code point value.
 * @returns {Number} The numeric value of a basic code point (for use in
 * representing integers) in the range `0` to `base - 1`, or `base` if
 * the code point does not represent a value.
 */
const basicToDigit = function(codePoint) {
	if (codePoint - 0x30 < 0x0A) {
		return codePoint - 0x16;
	}
	if (codePoint - 0x41 < 0x1A) {
		return codePoint - 0x41;
	}
	if (codePoint - 0x61 < 0x1A) {
		return codePoint - 0x61;
	}
	return base;
};

/**
 * Converts a digit/integer into a basic code point.
 * @see `basicToDigit()`
 * @private
 * @param {Number} digit The numeric value of a basic code point.
 * @returns {Number} The basic code point whose value (when used for
 * representing integers) is `digit`, which needs to be in the range
 * `0` to `base - 1`. If `flag` is non-zero, the uppercase form is
 * used; else, the lowercase form is used. The behavior is undefined
 * if `flag` is non-zero and `digit` has no uppercase form.
 */
const digitToBasic = function(digit, flag) {
	//  0..25 map to ASCII a..z or A..Z
	// 26..35 map to ASCII 0..9
	return digit + 22 + 75 * (digit < 26) - ((flag != 0) << 5);
};

/**
 * Bias adaptation function as per section 3.4 of RFC 3492.
 * https://tools.ietf.org/html/rfc3492#section-3.4
 * @private
 */
const adapt = function(delta, numPoints, firstTime) {
	let k = 0;
	delta = firstTime ? floor(delta / damp) : delta >> 1;
	delta += floor(delta / numPoints);
	for (/* no initialization */; delta > baseMinusTMin * tMax >> 1; k += base) {
		delta = floor(delta / baseMinusTMin);
	}
	return floor(k + (baseMinusTMin + 1) * delta / (delta + skew));
};

/**
 * Converts a Punycode string of ASCII-only symbols to a string of Unicode
 * symbols.
 * @memberOf punycode
 * @param {String} input The Punycode string of ASCII-only symbols.
 * @returns {String} The resulting string of Unicode symbols.
 */
const decode = function(input) {
	// Don't use UCS-2.
	const output = [];
	const inputLength = input.length;
	let i = 0;
	let n = initialN;
	let bias = initialBias;

	// Handle the basic code points: let `basic` be the number of input code
	// points before the last delimiter, or `0` if there is none, then copy
	// the first basic code points to the output.

	let basic = input.lastIndexOf(delimiter);
	if (basic < 0) {
		basic = 0;
	}

	for (let j = 0; j < basic; ++j) {
		// if it's not a basic code point
		if (input.charCodeAt(j) >= 0x80) {
			error('not-basic');
		}
		output.push(input.charCodeAt(j));
	}

	// Main decoding loop: start just after the last delimiter if any basic code
	// points were copied; start at the beginning otherwise.

	for (let index = basic > 0 ? basic + 1 : 0; index < inputLength; /* no final expression */) {

		// `index` is the index of the next character to be consumed.
		// Decode a generalized variable-length integer into `delta`,
		// which gets added to `i`. The overflow checking is easier
		// if we increase `i` as we go, then subtract off its starting
		// value at the end to obtain `delta`.
		let oldi = i;
		for (let w = 1, k = base; /* no condition */; k += base) {

			if (index >= inputLength) {
				error('invalid-input');
			}

			const digit = basicToDigit(input.charCodeAt(index++));

			if (digit >= base || digit > floor((maxInt - i) / w)) {
				error('overflow');
			}

			i += digit * w;
			const t = k <= bias ? tMin : (k >= bias + tMax ? tMax : k - bias);

			if (digit < t) {
				break;
			}

			const baseMinusT = base - t;
			if (w > floor(maxInt / baseMinusT)) {
				error('overflow');
			}

			w *= baseMinusT;

		}

		const out = output.length + 1;
		bias = adapt(i - oldi, out, oldi == 0);

		// `i` was supposed to wrap around from `out` to `0`,
		// incrementing `n` each time, so we'll fix that now:
		if (floor(i / out) > maxInt - n) {
			error('overflow');
		}

		n += floor(i / out);
		i %= out;

		// Insert `n` at position `i` of the output.
		output.splice(i++, 0, n);

	}

	return String.fromCodePoint(...output);
};

/**
 * Converts a string of Unicode symbols (e.g. a domain name label) to a
 * Punycode string of ASCII-only symbols.
 * @memberOf punycode
 * @param {String} input The string of Unicode symbols.
 * @returns {String} The resulting Punycode string of ASCII-only symbols.
 */
const encode = function(input) {
	const output = [];

	// Convert the input in UCS-2 to an array of Unicode code points.
	input = ucs2decode(input);

	// Cache the length.
	let inputLength = input.length;

	// Initialize the state.
	let n = initialN;
	let delta = 0;
	let bias = initialBias;

	// Handle the basic code points.
	for (const currentValue of input) {
		if (currentValue < 0x80) {
			output.push(stringFromCharCode(currentValue));
		}
	}

	let basicLength = output.length;
	let handledCPCount = basicLength;

	// `handledCPCount` is the number of code points that have been handled;
	// `basicLength` is the number of basic code points.

	// Finish the basic string with a delimiter unless it's empty.
	if (basicLength) {
		output.push(delimiter);
	}

	// Main encoding loop:
	while (handledCPCount < inputLength) {

		// All non-basic code points < n have been handled already. Find the next
		// larger one:
		let m = maxInt;
		for (const currentValue of input) {
			if (currentValue >= n && currentValue < m) {
				m = currentValue;
			}
		}

		// Increase `delta` enough to advance the decoder's <n,i> state to <m,0>,
		// but guard against overflow.
		const handledCPCountPlusOne = handledCPCount + 1;
		if (m - n > floor((maxInt - delta) / handledCPCountPlusOne)) {
			error('overflow');
		}

		delta += (m - n) * handledCPCountPlusOne;
		n = m;

		for (const currentValue of input) {
			if (currentValue < n && ++delta > maxInt) {
				error('overflow');
			}
			if (currentValue == n) {
				// Represent delta as a generalized variable-length integer.
				let q = delta;
				for (let k = base; /* no condition */; k += base) {
					const t = k <= bias ? tMin : (k >= bias + tMax ? tMax : k - bias);
					if (q < t) {
						break;
					}
					const qMinusT = q - t;
					const baseMinusT = base - t;
					output.push(
						stringFromCharCode(digitToBasic(t + qMinusT % baseMinusT, 0))
					);
					q = floor(qMinusT / baseMinusT);
				}

				output.push(stringFromCharCode(digitToBasic(q, 0)));
				bias = adapt(delta, handledCPCountPlusOne, handledCPCount == basicLength);
				delta = 0;
				++handledCPCount;
			}
		}

		++delta;
		++n;

	}
	return output.join('');
};

/**
 * Converts a Punycode string representing a domain name or an email address
 * to Unicode. Only the Punycoded parts of the input will be converted, i.e.
 * it doesn't matter if you call it on a string that has already been
 * converted to Unicode.
 * @memberOf punycode
 * @param {String} input The Punycoded domain name or email address to
 * convert to Unicode.
 * @returns {String} The Unicode representation of the given Punycode
 * string.
 */
const toUnicode = function(input) {
	return mapDomain(input, function(string) {
		return regexPunycode.test(string)
			? decode(string.slice(4).toLowerCase())
			: string;
	});
};

/**
 * Converts a Unicode string representing a domain name or an email address to
 * Punycode. Only the non-ASCII parts of the domain name will be converted,
 * i.e. it doesn't matter if you call it with a domain that's already in
 * ASCII.
 * @memberOf punycode
 * @param {String} input The domain name or email address to convert, as a
 * Unicode string.
 * @returns {String} The Punycode representation of the given domain name or
 * email address.
 */
const toASCII = function(input) {
	return mapDomain(input, function(string) {
		return regexNonASCII.test(string)
			? 'xn--' + encode(string)
			: string;
	});
};

/*--------------------------------------------------------------------------*/

/** Define the public API */
const punycode = {
	/**
	 * A string representing the current Punycode.js version number.
	 * @memberOf punycode
	 * @type String
	 */
	'version': '2.1.0',
	/**
	 * An object of methods to convert from JavaScript's internal character
	 * representation (UCS-2) to Unicode code points, and back.
	 * @see <https://mathiasbynens.be/notes/javascript-encoding>
	 * @memberOf punycode
	 * @type Object
	 */
	'ucs2': {
		'decode': ucs2decode,
		'encode': ucs2encode
	},
	'decode': decode,
	'encode': encode,
	'toASCII': toASCII,
	'toUnicode': toUnicode
};

// ### AUTO-END ###

Object.assign(exports, punycode);
})(lib.punycode);
lib.resource.add('nassh/release/lastver', 'text/plain',
'0.8.45'
);

lib.resource.add('nassh/release/highlights', 'text/plain',
'% Context menu available via Ctrl-Right Click.' +
'% \x1b]8;;https://goo.gl/muppJj#Is-there-a-way-to-try-early-releases-of-Secure-Shell\x07Secure Shell dev channel\x1b]8;;\x07 changed to nightly builds.' +
'% \x1b]8;;https://www.openssh.com/txt/release-7.9\x07OpenSSH upgraded to 7.9p1\x1b]8;;\x07.' +
'% Compression no longer enabled by default (ssh -C).'
);

