remoting/webapp/app_remoting/js/keyboard_layouts_menu.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
   7  * Class managing the host's available keyboard layouts, allowing the user to
   8  * select one that matches the local layout, or auto-selecting based on the
   9  * current locale.
  10  */
  11
  12 'use strict';
  13
  14 /** @suppress {duplicate} */
  15 var remoting = remoting || {};
  16
  17 /**
  18  * @param {remoting.ContextMenuAdapter} adapter
  19  * @constructor
  20  */
  21 remoting.KeyboardLayoutsMenu = function(adapter) {
  22   /**
  23    * @type {remoting.ContextMenuAdapter}
  24    * @private
  25    */
  26   this.adapter_ = adapter;
  27   /**
  28    * @type {remoting.SubmenuManager}
  29    * @private
  30    */
  31   this.submenuManager_ = new remoting.SubmenuManager(
  32       adapter,
  33       chrome.i18n.getMessage(/*i18n-content*/'KEYBOARD_LAYOUTS_SUBMENU_TITLE'),
  34       true);
  35   /**
  36    * @type {string}
  37    * @private
  38    */
  39   this.currentLayout_ = '';
  40
  41   adapter.addListener(this.onContextMenu_.bind(this));
  42 };
  43
  44 /**
  45  * @param {Array<string>} layouts The keyboard layouts available on the host,
  46  *   for example en-US, de-DE
  47  * @param {string} currentLayout The layout currently active on the host.
  48  */
  49 remoting.KeyboardLayoutsMenu.prototype.setLayouts =
  50     function(layouts, currentLayout) {
  51   this.submenuManager_.removeAll();
  52   this.currentLayout_ = '';
  53   for (var i = 0; i < layouts.length; ++i) {
  54     this.submenuManager_.add(this.makeMenuId_(layouts[i]), layouts[i]);
  55   }
  56   // Pick a suitable default layout.
  57   this.getBestLayout_(layouts, currentLayout,
  58                       this.setLayout_.bind(this, false));
  59 };
  60
  61 /**
  62  * Notify the host that a new keyboard layout has been selected.
  63  *
  64  * @param {boolean} saveToLocalStorage If true, save the specified layout to
  65  *     local storage.
  66  * @param {string} layout The new keyboard layout.
  67  * @private
  68  */
  69 remoting.KeyboardLayoutsMenu.prototype.setLayout_ =
  70     function(saveToLocalStorage, layout) {
  71   if (this.currentLayout_ != '') {
  72     this.adapter_.updateCheckState(
  73         this.makeMenuId_(this.currentLayout_), false);
  74   }
  75   this.adapter_.updateCheckState(this.makeMenuId_(layout), true);
  76   this.currentLayout_ = layout;
  77
  78   console.log("Setting the keyboard layout to '" + layout + "'");
  79   remoting.clientSession.sendClientMessage(
  80       'setKeyboardLayout',
  81       JSON.stringify({layout: layout}));
  82   if (saveToLocalStorage) {
  83     var params = {};
  84     params[remoting.KeyboardLayoutsMenu.KEY_] = layout;
  85     chrome.storage.local.set(params);
  86   }
  87 };
  88
  89 /**
  90  * Choose the best keyboard from the alternatives, based on the following
  91  * algorithm:
  92  *   - Search local storage by for a preferred keyboard layout for the app;
  93  *     if it is found, prefer it over the current locale, falling back on the
  94  *     latter only if no match is found.
  95  *   - If the candidate layout matches one of the supported layouts, use it.
  96  *   - Otherwise, if the language portion of the candidate matches that of
  97  *     any of the supported layouts, use the first such layout (e.g, en-AU
  98  *     will match either en-US or en-GB, whichever appears first).
  99  *   - Otherwise, use the host's current layout.
 100  *
 101  * @param {Array<string>} layouts
 102  * @param {string} currentHostLayout
 103  * @param {function(string):void} onDone
 104  * @private
 105  */
 106 remoting.KeyboardLayoutsMenu.prototype.getBestLayout_ =
 107     function(layouts, currentHostLayout, onDone) {
 108   /**
 109    * Extract the language id from a string that is either "language" (e.g.
 110    * "de") or "language-region" (e.g. "en-US").
 111    *
 112    * @param {string} layout
 113    * @return {string}
 114    */
 115   var getLanguage = function(layout) {
 116     var languageAndRegion = layout.split('-');
 117     switch (languageAndRegion.length) {
 118       case 1:
 119       case 2:
 120         return languageAndRegion[0];
 121       default:
 122         return '';
 123     }
 124   };
 125
 126   /** @param {Object<string>} storage */
 127   var chooseLayout = function(storage) {
 128     var configuredLayout = storage[remoting.KeyboardLayoutsMenu.KEY_];
 129     var tryLayouts = [ chrome.i18n.getUILanguage() ];
 130     if (configuredLayout && typeof(configuredLayout) == 'string') {
 131       tryLayouts.unshift(configuredLayout);
 132     }
 133     for (var i = 0; i < tryLayouts.length; ++i) {
 134       if (layouts.indexOf(tryLayouts[i]) != -1) {
 135         onDone(tryLayouts[i]);
 136         return;
 137       }
 138       var language = getLanguage(tryLayouts[i]);
 139       if (language) {
 140         for (var j = 0; j < layouts.length; ++j) {
 141           if (language == getLanguage(layouts[j])) {
 142             onDone(layouts[j]);
 143             return;
 144           }
 145         }
 146       }
 147     }
 148     // Neither the stored layout nor UI locale was suitable.
 149     onDone(currentHostLayout);
 150   };
 151
 152   chrome.storage.local.get(remoting.KeyboardLayoutsMenu.KEY_, chooseLayout);
 153 };
 154
 155 /**
 156  * Create a menu id from the given keyboard layout.
 157  *
 158  * @param {string} layout Keyboard layout
 159  * @return {string}
 160  * @private
 161  */
 162 remoting.KeyboardLayoutsMenu.prototype.makeMenuId_ = function(layout) {
 163   return 'layout@' + layout;
 164 };
 165
 166 /**
 167  * Handle a click on the application's context menu.
 168  *
 169  * @param {OnClickData=} info
 170  * @private
 171  */
 172 remoting.KeyboardLayoutsMenu.prototype.onContextMenu_ = function(info) {
 173   /** @type {Array<string>} */
 174   var components = info.menuItemId.split('@');
 175   if (components.length == 2 &&
 176       this.makeMenuId_(components[1]) == info.menuItemId) {
 177     this.setLayout_(true, components[1]);
 178   }
 179 };
 180
 181 /**
 182  * @type {string}
 183  * @private
 184  */
 185 remoting.KeyboardLayoutsMenu.KEY_ = 'preferred-keyboard-layout';