chrome/browser/resources/chromeos/chromevox/braille/braille_translator_manager.js

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 /**
   6  * @fileoverview Keeps track of the current braille translators.
   7  */
   8
   9 goog.provide('cvox.BrailleTranslatorManager');
  10
  11 goog.require('cvox.BrailleTable');
  12 goog.require('cvox.ExpandingBrailleTranslator');
  13 goog.require('cvox.LibLouis');
  14
  15 /**
  16  * @param {cvox.LibLouis=} opt_liblouisForTest Liblouis instance to use
  17  *     for testing.
  18  * @constructor
  19  */
  20 cvox.BrailleTranslatorManager = function(opt_liblouisForTest) {
  21   /**
  22    * @type {!cvox.LibLouis}
  23    * @private
  24    */
  25   this.liblouis_ = opt_liblouisForTest || new cvox.LibLouis(
  26       chrome.extension.getURL('braille/liblouis_nacl.nmf'),
  27       chrome.extension.getURL('braille/tables'));
  28   /**
  29    * @type {!Array<function()>}
  30    * @private
  31    */
  32   this.changeListeners_ = [];
  33   /**
  34    * @type {!Array<cvox.BrailleTable.Table>}
  35    * @private
  36    */
  37   this.tables_ = [];
  38   /**
  39    * @type {cvox.ExpandingBrailleTranslator}
  40    * @private
  41    */
  42   this.expandingTranslator_ = null;
  43   /**
  44    * @type {cvox.LibLouis.Translator}
  45    * @private
  46    */
  47   this.defaultTranslator_ = null;
  48   /**
  49    * @type {string?}
  50    * @private
  51    */
  52   this.defaultTableId_ = null;
  53   /**
  54    * @type {cvox.LibLouis.Translator}
  55    * @private
  56    */
  57   this.uncontractedTranslator_ = null;
  58   /**
  59    * @type {string?}
  60    * @private
  61    */
  62   this.uncontractedTableId_ = null;
  63
  64   if (!opt_liblouisForTest) {
  65     document.addEventListener('DOMContentLoaded',
  66                               this.loadLiblouis_.bind(this),
  67                               false);
  68   }
  69 };
  70
  71 cvox.BrailleTranslatorManager.prototype = {
  72   /**
  73    * Adds a listener to be called whenever there is a change in the
  74    * translator(s) returned by other methods of this instance.
  75    * @param {function()} listener The listener.
  76    */
  77   addChangeListener: function(listener) {
  78     this.changeListeners_.push(listener);
  79   },
  80
  81   /**
  82    * Refreshes the braille translator(s) used for input and output.  This
  83    * should be called when something has changed (such as a preference) to
  84    * make sure that the correct translator is used.
  85    */
  86   refresh: function() {
  87     var tables = this.tables_;
  88     if (tables.length == 0)
  89       return;
  90
  91     // First, see if we have a braille table set previously.
  92     var table = cvox.BrailleTable.forId(tables, localStorage['brailleTable']);
  93     if (!table) {
  94       // Match table against current locale.
  95       var currentLocale = chrome.i18n.getMessage('@@ui_locale').split(/[_-]/);
  96       var major = currentLocale[0];
  97       var minor = currentLocale[1];
  98       var firstPass = tables.filter(function(table) {
  99         return table.locale.split(/[_-]/)[0] == major;
 100       });
 101       if (firstPass.length > 0) {
 102         table = firstPass[0];
 103         if (minor) {
 104           var secondPass = firstPass.filter(function(table) {
 105             return table.locale.split(/[_-]/)[1] == minor;
 106           });
 107           if (secondPass.length > 0)
 108             table = secondPass[0];
 109         }
 110       }
 111     }
 112     if (!table)
 113       table = cvox.BrailleTable.forId(tables, 'en-US-comp8');
 114
 115     // TODO(plundblad): Only update when user explicitly selects a table
 116     // so that switching locales changes table by default.  crbug.com/441206.
 117     localStorage['brailleTable'] = table.id;
 118     if (!localStorage['brailleTable6'])
 119       localStorage['brailleTable6'] = 'en-US-g1';
 120     if (!localStorage['brailleTable8'])
 121       localStorage['brailleTable8'] = 'en-US-comp8';
 122
 123     if (table.dots == '6') {
 124       localStorage['brailleTableType'] = 'brailleTable6';
 125       localStorage['brailleTable6'] = table.id;
 126     } else {
 127       localStorage['brailleTableType'] = 'brailleTable8';
 128       localStorage['brailleTable8'] = table.id;
 129     }
 130
 131     // If the user explicitly set an 8 dot table, use that when looking
 132     // for an uncontracted table.  Otherwise, use the current table and let
 133     // getUncontracted find an appropriate corresponding table.
 134     var table8Dot = cvox.BrailleTable.forId(tables,
 135                                             localStorage['brailleTable8']);
 136     var uncontractedTable = cvox.BrailleTable.getUncontracted(
 137         tables, table8Dot || table);
 138
 139     var newDefaultTableId = table.id;
 140     var newUncontractedTableId = table.id === uncontractedTable.id ?
 141         null : uncontractedTable.id;
 142     if (newDefaultTableId === this.defaultTableId_ &&
 143         newUncontractedTableId === this.uncontractedTableId_) {
 144       return;
 145     }
 146
 147     var finishRefresh = function(defaultTranslator, uncontractedTranslator) {
 148       this.defaultTableId_ = newDefaultTableId;
 149       this.uncontractedTableId_ = newUncontractedTableId;
 150       this.expandingTranslator_ = new cvox.ExpandingBrailleTranslator(
 151           defaultTranslator, uncontractedTranslator);
 152       this.defaultTranslator_ = defaultTranslator;
 153       this.uncontractedTranslator_ = uncontractedTranslator;
 154       this.changeListeners_.forEach(function(listener) { listener(); });
 155     }.bind(this);
 156
 157     this.liblouis_.getTranslator(table.fileNames, function(translator) {
 158       if (!newUncontractedTableId) {
 159         finishRefresh(translator, null);
 160       } else {
 161         this.liblouis_.getTranslator(
 162             uncontractedTable.fileNames,
 163             function(uncontractedTranslator) {
 164               finishRefresh(translator, uncontractedTranslator);
 165             });
 166           }
 167     }.bind(this));
 168   },
 169
 170   /**
 171    * @return {cvox.ExpandingBrailleTranslator} The current expanding braille
 172    *     translator, or {@code null} if none is available.
 173    */
 174   getExpandingTranslator: function() {
 175     return this.expandingTranslator_;
 176   },
 177
 178   /**
 179    * @return {cvox.LibLouis.Translator} The current braille translator to use
 180    *     by default, or {@code null} if none is available.
 181    */
 182   getDefaultTranslator: function() {
 183     return this.defaultTranslator_;
 184   },
 185
 186   /**
 187    * @return {cvox.LibLouis.Translator} The current uncontracted braille
 188    *     translator, or {@code null} if it is the same as the default
 189    *     translator.
 190    */
 191   getUncontractedTranslator: function() {
 192     return this.uncontractedTranslator_;
 193   },
 194
 195   /**
 196    * Asynchronously fetches the list of braille tables and refreshes the
 197    * translators when done.
 198    * @private
 199    */
 200   fetchTables_: function() {
 201     cvox.BrailleTable.getAll(function(tables) {
 202       this.tables_ = tables;
 203       this.refresh();
 204     }.bind(this));
 205   },
 206
 207   /**
 208    * Loads the liblouis instance by attaching it to the document.
 209    * @private
 210    */
 211   loadLiblouis_: function() {
 212     // Cast away nullability.  When the document is loaded, it will always
 213     // have a body.
 214     this.liblouis_.attachToElement(
 215         /** @type {!HTMLBodyElement} */ (document.body));
 216     this.fetchTables_();
 217   },
 218
 219   /**
 220    * @return {!cvox.LibLouis} The liblouis instance used by this object.
 221    */
 222   getLibLouisForTest: function() {
 223     return this.liblouis_;
 224   },
 225
 226   /**
 227    * @return {!Array<cvox.BrailleTable.Table>} The currently loaded braille
 228    *     tables, or an empty array if they are not yet loaded.
 229    */
 230   getTablesForTest: function() {
 231     return this.tables_;
 232   }
 233 };