accessible/jsat/OutputGenerator.jsm
author Birunthan Mohanathas <birunthan@mohanathas.com>
Sun, 22 Jun 2014 10:15:19 -0700
changeset 190268 85b4fe3a7fa90caa702aa36f6985c667d9e01b02
parent 181131 accessible/src/jsat/OutputGenerator.jsm@8c3758dd1ba8cabb8df03180f646187b07c60d11
child 198111 d6059e806022b7b93748c32ba8fbb1e4911b6bfa
permissions -rw-r--r--
Bug 1028563 - Part 1: Flatten accessible/src/ directory. rs=surkov

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

'use strict';

const Cc = Components.classes;
const Ci = Components.interfaces;
const Cu = Components.utils;
const Cr = Components.results;

const INCLUDE_DESC = 0x01;
const INCLUDE_NAME = 0x02;
const INCLUDE_VALUE = 0x04;
const INCLUDE_CUSTOM = 0x08;
const NAME_FROM_SUBTREE_RULE = 0x10;
const IGNORE_EXPLICIT_NAME = 0x20;

const OUTPUT_DESC_FIRST = 0;
const OUTPUT_DESC_LAST = 1;

Cu.import('resource://gre/modules/XPCOMUtils.jsm');
XPCOMUtils.defineLazyModuleGetter(this, 'Utils',
  'resource://gre/modules/accessibility/Utils.jsm');
XPCOMUtils.defineLazyModuleGetter(this, 'PrefCache',
  'resource://gre/modules/accessibility/Utils.jsm');
XPCOMUtils.defineLazyModuleGetter(this, 'Logger',
  'resource://gre/modules/accessibility/Utils.jsm');
XPCOMUtils.defineLazyModuleGetter(this, 'PluralForm',
  'resource://gre/modules/PluralForm.jsm');
XPCOMUtils.defineLazyModuleGetter(this, 'Roles',
  'resource://gre/modules/accessibility/Constants.jsm');
XPCOMUtils.defineLazyModuleGetter(this, 'States',
  'resource://gre/modules/accessibility/Constants.jsm');

this.EXPORTED_SYMBOLS = ['UtteranceGenerator', 'BrailleGenerator'];

this.OutputGenerator = {

  defaultOutputOrder: OUTPUT_DESC_LAST,

  /**
   * Generates output for a PivotContext.
   * @param {PivotContext} aContext object that generates and caches
   *    context information for a given accessible and its relationship with
   *    another accessible.
   * @return {Object} An object that neccessarily has an output property which
   *    is an array of strings. Depending on the utterance order,
   *    the strings describe the context for an accessible object either
   *    starting from the accessible's ancestry or accessible's subtree.
   *    The object may also have properties specific to the type of output
   *    generated.
   */
  genForContext: function genForContext(aContext) {
    let output = [];
    let self = this;
    let addOutput = function addOutput(aAccessible) {
      output.push.apply(output, self.genForObject(aAccessible, aContext));
    };
    let ignoreSubtree = function ignoreSubtree(aAccessible) {
      let roleString = Utils.AccRetrieval.getStringRole(aAccessible.role);
      let nameRule = self.roleRuleMap[roleString] || 0;
      // Ignore subtree if the name is explicit and the role's name rule is the
      // NAME_FROM_SUBTREE_RULE.
      return (((nameRule & INCLUDE_VALUE) && aAccessible.value) ||
              ((nameRule & NAME_FROM_SUBTREE_RULE) &&
               (Utils.getAttributes(aAccessible)['explicit-name'] === 'true' &&
               !(nameRule & IGNORE_EXPLICIT_NAME))));
    };

    let contextStart = this._getContextStart(aContext);

    if (this.outputOrder === OUTPUT_DESC_FIRST) {
      contextStart.forEach(addOutput);
      addOutput(aContext.accessible);
      [addOutput(node) for
        (node of aContext.subtreeGenerator(true, ignoreSubtree))];
    } else {
      [addOutput(node) for
        (node of aContext.subtreeGenerator(false, ignoreSubtree))];
      addOutput(aContext.accessible);
      contextStart.reverse().forEach(addOutput);
    }

    // Clean up the white space.
    let trimmed;
    output = [trimmed for (word of output) if (trimmed = word.trim())];
    return {output: output};
  },


  /**
   * Generates output for an object.
   * @param {nsIAccessible} aAccessible accessible object to generate output
   *    for.
   * @param {PivotContext} aContext object that generates and caches
   *    context information for a given accessible and its relationship with
   *    another accessible.
   * @return {Array} Two string array. The first string describes the object
   *    and its state. The second string is the object's name. Whether the
   *    object's description or it's role is included is determined by
   *    {@link roleRuleMap}.
   */
  genForObject: function genForObject(aAccessible, aContext) {
    let roleString = Utils.AccRetrieval.getStringRole(aAccessible.role);
    let func = this.objectOutputFunctions[
      OutputGenerator._getOutputName(roleString)] ||
      this.objectOutputFunctions.defaultFunc;

    let flags = this.roleRuleMap[roleString] || 0;

    if (aAccessible.childCount == 0)
      flags |= INCLUDE_NAME;

    return func.apply(this, [aAccessible, roleString,
                             Utils.getState(aAccessible), flags, aContext]);
  },

  /**
   * Generates output for an action performed.
   * @param {nsIAccessible} aAccessible accessible object that the action was
   *    invoked in.
   * @param {string} aActionName the name of the action, one of the keys in
   *    {@link gActionMap}.
   * @return {Array} A one string array with the action.
   */
  genForAction: function genForAction(aObject, aActionName) {},

  /**
   * Generates output for an announcement. Basically attempts to localize
   * the announcement string.
   * @param {string} aAnnouncement unlocalized announcement.
   * @return {Array} A one string array with the announcement.
   */
  genForAnnouncement: function genForAnnouncement(aAnnouncement) {},

  /**
   * Generates output for a tab state change.
   * @param {nsIAccessible} aAccessible accessible object of the tab's attached
   *    document.
   * @param {string} aTabState the tab state name, see
   *    {@link Presenter.tabStateChanged}.
   * @return {Array} The tab state utterace.
   */
  genForTabStateChange: function genForTabStateChange(aObject, aTabState) {},

  /**
   * Generates output for announcing entering and leaving editing mode.
   * @param {aIsEditing} boolean true if we are in editing mode
   * @return {Array} The mode utterance
   */
  genForEditingMode: function genForEditingMode(aIsEditing) {},

  _getContextStart: function getContextStart(aContext) {},

  _addName: function _addName(aOutput, aAccessible, aFlags) {
    let name;
    if ((Utils.getAttributes(aAccessible)['explicit-name'] === 'true' &&
         !(aFlags & IGNORE_EXPLICIT_NAME)) || (aFlags & INCLUDE_NAME)) {
      name = aAccessible.name;
    }

    let description = aAccessible.description;
    if (description) {
      // Compare against the calculated name unconditionally, regardless of name rule,
      // so we can make sure we don't speak duplicated descriptions
      let tmpName = name || aAccessible.name;
      if (tmpName && (description !== tmpName)) {
        name = name || '';
        name = this.outputOrder === OUTPUT_DESC_FIRST ?
          description + ' - ' + name :
          name + ' - ' + description;
      }
    }

    if (name) {
      aOutput[this.outputOrder === OUTPUT_DESC_FIRST ?
        'push' : 'unshift'](name);
    }
  },

  /**
   * Adds a landmark role to the output if available.
   * @param {Array} aOutput Output array.
   * @param {nsIAccessible} aAccessible current accessible object.
   */
  _addLandmark: function _addLandmark(aOutput, aAccessible) {
    let landmarkName = Utils.getLandmarkName(aAccessible);
    if (!landmarkName) {
      return;
    }

    let landmark = Utils.stringBundle.GetStringFromName(landmarkName);
    if (!landmark) {
      return;
    }

    aOutput[this.outputOrder === OUTPUT_DESC_FIRST ? 'unshift' : 'push'](
      landmark);
  },

  /**
   * Adds an entry type attribute to the description if available.
   * @param {Array} aDesc Description array.
   * @param {nsIAccessible} aAccessible current accessible object.
   * @param {String} aRoleStr aAccessible's role string.
   */
  _addType: function _addType(aDesc, aAccessible, aRoleStr) {
    if (aRoleStr !== 'entry') {
      return;
    }

    let typeName = Utils.getAttributes(aAccessible)['text-input-type'];
    // Ignore the the input type="text" case.
    if (!typeName || typeName === 'text') {
      return;
    }
    typeName = 'textInputType_' + typeName;
    try {
      aDesc.push(Utils.stringBundle.GetStringFromName(typeName));
    } catch (x) {
      Logger.warning('Failed to get a string from a bundle for', typeName);
    }
  },

  get outputOrder() {
    if (!this._utteranceOrder) {
      this._utteranceOrder = new PrefCache('accessibility.accessfu.utterance');
    }
    return typeof this._utteranceOrder.value === 'number' ?
      this._utteranceOrder.value : this.defaultOutputOrder;
  },

  _getOutputName: function _getOutputName(aName) {
    return aName.replace(' ', '');
  },

  _getLocalizedRole: function _getLocalizedRole(aRoleStr) {},

  _getLocalizedState: function _getLocalizedState(aState) {},

  _getPluralFormString: function _getPluralFormString(aString, aCount) {
    let str = Utils.stringBundle.GetStringFromName(this._getOutputName(aString));
    str = PluralForm.get(aCount, str);
    return str.replace('#1', aCount);
  },

  roleRuleMap: {
    'menubar': INCLUDE_DESC,
    'scrollbar': INCLUDE_DESC,
    'grip': INCLUDE_DESC,
    'alert': INCLUDE_DESC | INCLUDE_NAME,
    'menupopup': INCLUDE_DESC,
    'menuitem': INCLUDE_DESC | NAME_FROM_SUBTREE_RULE,
    'tooltip': INCLUDE_DESC | NAME_FROM_SUBTREE_RULE,
    'columnheader': INCLUDE_DESC | NAME_FROM_SUBTREE_RULE,
    'rowheader': INCLUDE_DESC | NAME_FROM_SUBTREE_RULE,
    'column': NAME_FROM_SUBTREE_RULE,
    'row': NAME_FROM_SUBTREE_RULE,
    'cell': INCLUDE_DESC | INCLUDE_NAME,
    'application': INCLUDE_NAME,
    'document': INCLUDE_NAME,
    'grouping': INCLUDE_DESC | INCLUDE_NAME,
    'toolbar': INCLUDE_DESC,
    'table': INCLUDE_DESC | INCLUDE_NAME,
    'link': INCLUDE_DESC | NAME_FROM_SUBTREE_RULE,
    'helpballoon': NAME_FROM_SUBTREE_RULE,
    'list': INCLUDE_DESC | INCLUDE_NAME,
    'listitem': INCLUDE_DESC | NAME_FROM_SUBTREE_RULE,
    'outline': INCLUDE_DESC,
    'outlineitem': INCLUDE_DESC | NAME_FROM_SUBTREE_RULE,
    'pagetab': INCLUDE_DESC | NAME_FROM_SUBTREE_RULE,
    'graphic': INCLUDE_DESC,
    'pushbutton': INCLUDE_DESC | NAME_FROM_SUBTREE_RULE,
    'checkbutton': INCLUDE_DESC | NAME_FROM_SUBTREE_RULE,
    'radiobutton': INCLUDE_DESC | NAME_FROM_SUBTREE_RULE,
    'buttondropdown': NAME_FROM_SUBTREE_RULE,
    'combobox': INCLUDE_DESC,
    'droplist': INCLUDE_DESC,
    'progressbar': INCLUDE_DESC | INCLUDE_VALUE,
    'slider': INCLUDE_DESC | INCLUDE_VALUE,
    'spinbutton': INCLUDE_DESC | INCLUDE_VALUE,
    'diagram': INCLUDE_DESC,
    'animation': INCLUDE_DESC,
    'equation': INCLUDE_DESC,
    'buttonmenu': INCLUDE_DESC | NAME_FROM_SUBTREE_RULE,
    'buttondropdowngrid': NAME_FROM_SUBTREE_RULE,
    'pagetablist': INCLUDE_DESC,
    'canvas': INCLUDE_DESC,
    'check menu item': INCLUDE_DESC | NAME_FROM_SUBTREE_RULE,
    'label': INCLUDE_DESC | NAME_FROM_SUBTREE_RULE,
    'password text': INCLUDE_DESC,
    'popup menu': INCLUDE_DESC,
    'radio menu item': INCLUDE_DESC | NAME_FROM_SUBTREE_RULE,
    'table column header': NAME_FROM_SUBTREE_RULE,
    'table row header': NAME_FROM_SUBTREE_RULE,
    'tear off menu item': NAME_FROM_SUBTREE_RULE,
    'toggle button': INCLUDE_DESC | NAME_FROM_SUBTREE_RULE,
    'parent menuitem': NAME_FROM_SUBTREE_RULE,
    'header': INCLUDE_DESC,
    'footer': INCLUDE_DESC,
    'entry': INCLUDE_DESC | INCLUDE_NAME | INCLUDE_VALUE,
    'caption': INCLUDE_DESC,
    'document frame': INCLUDE_DESC,
    'heading': INCLUDE_DESC,
    'calendar': INCLUDE_DESC | INCLUDE_NAME,
    'combobox list': INCLUDE_DESC,
    'combobox option': INCLUDE_DESC | NAME_FROM_SUBTREE_RULE,
    'listbox option': INCLUDE_DESC | NAME_FROM_SUBTREE_RULE,
    'listbox rich option': NAME_FROM_SUBTREE_RULE,
    'gridcell': NAME_FROM_SUBTREE_RULE,
    'check rich option': NAME_FROM_SUBTREE_RULE,
    'term': NAME_FROM_SUBTREE_RULE,
    'definition': NAME_FROM_SUBTREE_RULE,
    'key': NAME_FROM_SUBTREE_RULE,
    'image map': INCLUDE_DESC,
    'option': INCLUDE_DESC,
    'listbox': INCLUDE_DESC,
    'definitionlist': INCLUDE_DESC | INCLUDE_NAME,
    'dialog': INCLUDE_DESC | INCLUDE_NAME,
    'chrome window': IGNORE_EXPLICIT_NAME,
    'app root': IGNORE_EXPLICIT_NAME },

  objectOutputFunctions: {
    _generateBaseOutput: function _generateBaseOutput(aAccessible, aRoleStr, aState, aFlags) {
      let output = [];

      if (aFlags & INCLUDE_DESC) {
        let desc = this._getLocalizedState(aState);
        let roleStr = this._getLocalizedRole(aRoleStr);
        if (roleStr) {
          this._addType(desc, aAccessible, aRoleStr);
          desc.push(roleStr);
        }
        output.push(desc.join(' '));
      }

      if (aFlags & INCLUDE_VALUE) {
        let value = aAccessible.value;
        if (value) {
          output[this.outputOrder === OUTPUT_DESC_FIRST ?
                 'push' : 'unshift'](value);
        }
      }

      this._addName(output, aAccessible, aFlags);
      this._addLandmark(output, aAccessible);

      return output;
    },

    label: function label(aAccessible, aRoleStr, aState, aFlags, aContext) {
      if (aContext.isNestedControl ||
          aContext.accessible == Utils.getEmbeddedControl(aAccessible)) {
        // If we are on a nested control, or a nesting label,
        // we don't need the context.
        return [];
      }

      return this.objectOutputFunctions.defaultFunc.apply(this, arguments);
    },

    entry: function entry(aAccessible, aRoleStr, aState, aFlags) {
      let rolestr = aState.contains(States.MULTI_LINE) ? 'textarea' : 'entry';
      return this.objectOutputFunctions.defaultFunc.apply(
        this, [aAccessible, rolestr, aState, aFlags]);
    },

    pagetab: function pagetab(aAccessible, aRoleStr, aState, aFlags) {
      let localizedRole = this._getLocalizedRole(aRoleStr);
      let itemno = {};
      let itemof = {};
      aAccessible.groupPosition({}, itemof, itemno);
      let output = [];
      let desc = this._getLocalizedState(aState);
      desc.push(
        Utils.stringBundle.formatStringFromName(
          'objItemOf', [localizedRole, itemno.value, itemof.value], 3));
      output.push(desc.join(' '));

      this._addName(output, aAccessible, aFlags);
      this._addLandmark(output, aAccessible);

      return output;
    },

    table: function table(aAccessible, aRoleStr, aState, aFlags) {
      let output = [];
      let table;
      try {
        table = aAccessible.QueryInterface(Ci.nsIAccessibleTable);
      } catch (x) {
        Logger.logException(x);
        return output;
      } finally {
        // Check if it's a layout table, and bail out if true.
        // We don't want to speak any table information for layout tables.
        if (table.isProbablyForLayout()) {
          return output;
        }
        let tableColumnInfo = this._getPluralFormString('tableColumnInfo',
          table.columnCount);
        let tableRowInfo = this._getPluralFormString('tableRowInfo',
          table.rowCount);
        output.push(Utils.stringBundle.formatStringFromName(
          this._getOutputName('tableInfo'), [this._getLocalizedRole(aRoleStr),
            tableColumnInfo, tableRowInfo], 3));
        this._addName(output, aAccessible, aFlags);
        this._addLandmark(output, aAccessible);
        return output;
      }
    }
  }
};

/**
 * Generates speech utterances from objects, actions and state changes.
 * An utterance is an array of strings.
 *
 * It should not be assumed that flattening an utterance array would create a
 * gramatically correct sentence. For example, {@link genForObject} might
 * return: ['graphic', 'Welcome to my home page'].
 * Each string element in an utterance should be gramatically correct in itself.
 * Another example from {@link genForObject}: ['list item 2 of 5', 'Alabama'].
 *
 * An utterance is ordered from the least to the most important. Speaking the
 * last string usually makes sense, but speaking the first often won't.
 * For example {@link genForAction} might return ['button', 'clicked'] for a
 * clicked event. Speaking only 'clicked' makes sense. Speaking 'button' does
 * not.
 */
this.UtteranceGenerator = {
  __proto__: OutputGenerator,

  gActionMap: {
    jump: 'jumpAction',
    press: 'pressAction',
    check: 'checkAction',
    uncheck: 'uncheckAction',
    select: 'selectAction',
    unselect: 'unselectAction',
    open: 'openAction',
    close: 'closeAction',
    switch: 'switchAction',
    click: 'clickAction',
    collapse: 'collapseAction',
    expand: 'expandAction',
    activate: 'activateAction',
    cycle: 'cycleAction'
  },

  //TODO: May become more verbose in the future.
  genForAction: function genForAction(aObject, aActionName) {
    return [Utils.stringBundle.GetStringFromName(this.gActionMap[aActionName])];
  },

  genForLiveRegion: function genForLiveRegion(aContext, aIsHide, aModifiedText) {
    let utterance = [];
    if (aIsHide) {
      utterance.push(Utils.stringBundle.GetStringFromName('hidden'));
    }
    return utterance.concat(
      aModifiedText || this.genForContext(aContext).output);
  },

  genForAnnouncement: function genForAnnouncement(aAnnouncement) {
    try {
      return [Utils.stringBundle.GetStringFromName(aAnnouncement)];
    } catch (x) {
      return [aAnnouncement];
    }
  },

  genForTabStateChange: function genForTabStateChange(aObject, aTabState) {
    switch (aTabState) {
      case 'newtab':
        return [Utils.stringBundle.GetStringFromName('tabNew')];
      case 'loading':
        return [Utils.stringBundle.GetStringFromName('tabLoading')];
      case 'loaded':
        return [aObject.name || '',
                Utils.stringBundle.GetStringFromName('tabLoaded')];
      case 'loadstopped':
        return [Utils.stringBundle.GetStringFromName('tabLoadStopped')];
      case 'reload':
        return [Utils.stringBundle.GetStringFromName('tabReload')];
      default:
        return [];
    }
  },

  genForEditingMode: function genForEditingMode(aIsEditing) {
    return [Utils.stringBundle.GetStringFromName(
      aIsEditing ? 'editingMode' : 'navigationMode')];
  },

  objectOutputFunctions: {

    __proto__: OutputGenerator.objectOutputFunctions,

    defaultFunc: function defaultFunc(aAccessible, aRoleStr, aState, aFlags) {
      return this.objectOutputFunctions._generateBaseOutput.apply(this, arguments);
    },

    heading: function heading(aAccessible, aRoleStr, aState, aFlags) {
      let level = {};
      aAccessible.groupPosition(level, {}, {});
      let utterance =
        [Utils.stringBundle.formatStringFromName(
          'headingLevel', [level.value], 1)];

      this._addName(utterance, aAccessible, aFlags);
      this._addLandmark(utterance, aAccessible);

      return utterance;
    },

    listitem: function listitem(aAccessible, aRoleStr, aState, aFlags) {
      let itemno = {};
      let itemof = {};
      aAccessible.groupPosition({}, itemof, itemno);
      let utterance = [];
      if (itemno.value == 1) // Start of list
        utterance.push(Utils.stringBundle.GetStringFromName('listStart'));
      else if (itemno.value == itemof.value) // last item
        utterance.push(Utils.stringBundle.GetStringFromName('listEnd'));

      this._addName(utterance, aAccessible, aFlags);
      this._addLandmark(utterance, aAccessible);

      return utterance;
    },

    list: function list(aAccessible, aRoleStr, aState, aFlags) {
      return this._getListUtterance
        (aAccessible, aRoleStr, aFlags, aAccessible.childCount);
    },

    definitionlist: function definitionlist(aAccessible, aRoleStr, aState, aFlags) {
      return this._getListUtterance
        (aAccessible, aRoleStr, aFlags, aAccessible.childCount / 2);
    },

    application: function application(aAccessible, aRoleStr, aState, aFlags) {
      // Don't utter location of applications, it gets tiring.
      if (aAccessible.name != aAccessible.DOMNode.location)
        return this.objectOutputFunctions.defaultFunc.apply(this,
          [aAccessible, aRoleStr, aState, aFlags]);

      return [];
    },

    cell: function cell(aAccessible, aRoleStr, aState, aFlags, aContext) {
      let utterance = [];
      let cell = aContext.getCellInfo(aAccessible);
      if (cell) {
        let desc = [];
        let addCellChanged = function addCellChanged(aDesc, aChanged, aString, aIndex) {
          if (aChanged) {
            aDesc.push(Utils.stringBundle.formatStringFromName(aString,
              [aIndex + 1], 1));
          }
        };
        let addExtent = function addExtent(aDesc, aExtent, aString) {
          if (aExtent > 1) {
            aDesc.push(Utils.stringBundle.formatStringFromName(aString,
              [aExtent], 1));
          }
        };
        let addHeaders = function addHeaders(aDesc, aHeaders) {
          if (aHeaders.length > 0) {
            aDesc.push.apply(aDesc, aHeaders);
          }
        };

        addCellChanged(desc, cell.columnChanged, 'columnInfo', cell.columnIndex);
        addCellChanged(desc, cell.rowChanged, 'rowInfo', cell.rowIndex);

        addExtent(desc, cell.columnExtent, 'spansColumns');
        addExtent(desc, cell.rowExtent, 'spansRows');

        addHeaders(desc, cell.columnHeaders);
        addHeaders(desc, cell.rowHeaders);

        utterance.push(desc.join(' '));
      }

      this._addName(utterance, aAccessible, aFlags);
      this._addLandmark(utterance, aAccessible);

      return utterance;
    },

    columnheader: function columnheader() {
      return this.objectOutputFunctions.cell.apply(this, arguments);
    },

    rowheader: function rowheader() {
      return this.objectOutputFunctions.cell.apply(this, arguments);
    },

    statictext: function statictext(aAccessible) {
      if (Utils.isListItemDecorator(aAccessible, true)) {
        return [];
      }

      return this.objectOutputFunctions.defaultFunc.apply(this, arguments);
    }
  },

  _getContextStart: function _getContextStart(aContext) {
    return aContext.newAncestry;
  },

  _getLocalizedRole: function _getLocalizedRole(aRoleStr) {
    try {
      return Utils.stringBundle.GetStringFromName(
        this._getOutputName(aRoleStr));
    } catch (x) {
      return '';
    }
  },

  _getLocalizedState: function _getLocalizedState(aState) {
    let stateUtterances = [];

    if (aState.contains(States.UNAVAILABLE)) {
      stateUtterances.push(
        Utils.stringBundle.GetStringFromName('stateUnavailable'));
    }

    // Don't utter this in Jelly Bean, we let TalkBack do it for us there.
    // This is because we expose the checked information on the node itself.
    // XXX: this means the checked state is always appended to the end, regardless
    // of the utterance ordering preference.
    if ((Utils.AndroidSdkVersion < 16 || Utils.MozBuildApp === 'browser') &&
      aState.contains(States.CHECKABLE)) {
      let statetr = aState.contains(States.CHECKED) ?
        'stateChecked' : 'stateNotChecked';
      stateUtterances.push(Utils.stringBundle.GetStringFromName(statetr));
    }

    if (aState.contains(States.PRESSED)) {
      stateUtterances.push(
        Utils.stringBundle.GetStringFromName('statePressed'));
    }

    if (aState.contains(States.EXPANDABLE)) {
      let statetr = aState.contains(States.EXPANDED) ?
        'stateExpanded' : 'stateCollapsed';
      stateUtterances.push(Utils.stringBundle.GetStringFromName(statetr));
    }

    if (aState.contains(States.REQUIRED)) {
      stateUtterances.push(
        Utils.stringBundle.GetStringFromName('stateRequired'));
    }

    if (aState.contains(States.TRAVERSED)) {
      stateUtterances.push(
        Utils.stringBundle.GetStringFromName('stateTraversed'));
    }

    if (aState.contains(States.HASPOPUP)) {
      stateUtterances.push(
        Utils.stringBundle.GetStringFromName('stateHasPopup'));
    }

    if (aState.contains(States.SELECTED)) {
      stateUtterances.push(
        Utils.stringBundle.GetStringFromName('stateSelected'));
    }

    return stateUtterances;
  },

  _getListUtterance: function _getListUtterance(aAccessible, aRoleStr, aFlags, aItemCount) {
    let desc = [];
    let roleStr = this._getLocalizedRole(aRoleStr);
    if (roleStr) {
      desc.push(roleStr);
    }
    desc.push(this._getPluralFormString('listItemsCount', aItemCount));
    let utterance = [desc.join(' ')];

    this._addName(utterance, aAccessible, aFlags);
    this._addLandmark(utterance, aAccessible);

    return utterance;
  }
};


this.BrailleGenerator = {
  __proto__: OutputGenerator,

  genForContext: function genForContext(aContext) {
    let output = OutputGenerator.genForContext.apply(this, arguments);

    let acc = aContext.accessible;

    // add the static text indicating a list item; do this for both listitems or
    // direct first children of listitems, because these are both common browsing
    // scenarios
    let addListitemIndicator = function addListitemIndicator(indicator = '*') {
      output.output.unshift(indicator);
    };

    if (acc.indexInParent === 1 &&
        acc.parent.role == Roles.LISTITEM &&
        acc.previousSibling.role == Roles.STATICTEXT) {
      if (acc.parent.parent && acc.parent.parent.DOMNode &&
          acc.parent.parent.DOMNode.nodeName == 'UL') {
        addListitemIndicator();
      } else {
        addListitemIndicator(acc.previousSibling.name.trim());
      }
    } else if (acc.role == Roles.LISTITEM && acc.firstChild &&
               acc.firstChild.role == Roles.STATICTEXT) {
      if (acc.parent.DOMNode.nodeName == 'UL') {
        addListitemIndicator();
      } else {
        addListitemIndicator(acc.firstChild.name.trim());
      }
    }

    if (acc instanceof Ci.nsIAccessibleText) {
      output.endOffset = this.outputOrder === OUTPUT_DESC_FIRST ?
                         output.output.join(' ').length : acc.characterCount;
      output.startOffset = output.endOffset - acc.characterCount;
    }

    return output;
  },

  objectOutputFunctions: {

    __proto__: OutputGenerator.objectOutputFunctions,

    defaultFunc: function defaultFunc(aAccessible, aRoleStr, aState, aFlags) {
      return this.objectOutputFunctions._generateBaseOutput.apply(this, arguments);
    },

    listitem: function listitem(aAccessible, aRoleStr, aState, aFlags) {
      let braille = [];

      this._addName(braille, aAccessible, aFlags);
      this._addLandmark(braille, aAccessible);

      return braille;
    },

    cell: function cell(aAccessible, aRoleStr, aState, aFlags, aContext) {
      let braille = [];
      let cell = aContext.getCellInfo(aAccessible);
      if (cell) {
        let desc = [];
        let addHeaders = function addHeaders(aDesc, aHeaders) {
          if (aHeaders.length > 0) {
            aDesc.push.apply(aDesc, aHeaders);
          }
        };

        desc.push(Utils.stringBundle.formatStringFromName(
          this._getOutputName('cellInfo'), [cell.columnIndex + 1,
            cell.rowIndex + 1], 2));

        addHeaders(desc, cell.columnHeaders);
        addHeaders(desc, cell.rowHeaders);
        braille.push(desc.join(' '));
      }

      this._addName(braille, aAccessible, aFlags);
      this._addLandmark(braille, aAccessible);
      return braille;
    },

    columnheader: function columnheader() {
      return this.objectOutputFunctions.cell.apply(this, arguments);
    },

    rowheader: function rowheader() {
      return this.objectOutputFunctions.cell.apply(this, arguments);
    },

    statictext: function statictext(aAccessible, aRoleStr, aState, aFlags) {
      // Since we customize the list bullet's output, we add the static
      // text from the first node in each listitem, so skip it here.
      if (Utils.isListItemDecorator(aAccessible)) {
        return [];
      }

      return this.objectOutputFunctions._useStateNotRole.apply(this, arguments);
    },

    _useStateNotRole: function _useStateNotRole(aAccessible, aRoleStr, aState, aFlags) {
      let braille = [];

      let desc = this._getLocalizedState(aState, aAccessible.role);
      braille.push(desc.join(' '));

      this._addName(braille, aAccessible, aFlags);
      this._addLandmark(braille, aAccessible);

      return braille;
    },

    checkbutton: function checkbutton(aAccessible, aRoleStr, aState, aFlags) {
      return this.objectOutputFunctions._useStateNotRole.apply(this, arguments);
    },

    radiobutton: function radiobutton(aAccessible, aRoleStr, aState, aFlags) {
      return this.objectOutputFunctions._useStateNotRole.apply(this, arguments);
    },

    togglebutton: function radiobutton(aAccessible, aRoleStr, aState, aFlags) {
      return this.objectOutputFunctions._useStateNotRole.apply(this, arguments);
    }
  },

  _getContextStart: function _getContextStart(aContext) {
    if (aContext.accessible.parent.role == Roles.LINK) {
      return [aContext.accessible.parent];
    }

    return [];
  },

  _getOutputName: function _getOutputName(aName) {
    return OutputGenerator._getOutputName(aName) + 'Abbr';
  },

  _getLocalizedRole: function _getLocalizedRole(aRoleStr) {
    try {
      return Utils.stringBundle.GetStringFromName(
        this._getOutputName(aRoleStr));
    } catch (x) {
      try {
        return Utils.stringBundle.GetStringFromName(
          OutputGenerator._getOutputName(aRoleStr));
      } catch (y) {
        return '';
      }
    }
  },

  _getLocalizedState: function _getLocalizedState(aState, aRole) {
    let stateBraille = [];

    let getResultMarker = function getResultMarker(aMarker) {
      // aMarker is a simple boolean.
      let resultMarker = [];
      resultMarker.push('(');
      resultMarker.push(aMarker ? 'x' : ' ');
      resultMarker.push(')');

      return resultMarker.join('');
    };

    if (aState.contains(States.CHECKABLE)) {
      stateBraille.push(getResultMarker(aState.contains(States.CHECKED)));
    }

    if (aRole === Roles.TOGGLE_BUTTON) {
      stateBraille.push(getResultMarker(aState.contains(States.PRESSED)));
    }

    return stateBraille;
  }

};