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