Ensure WebView notifies desktop automation on creation, destruction, and change

chrome/browser/resources/chromeos/chromevox/cvox2/background/background.js

 // Copyright 2014 The Chromium 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 The entry point for all ChromeVox2 related code for the
  * background page.
  */
 
 goog.provide('Background');
 goog.provide('global');
 
 goog.require('AutomationPredicate');
 goog.require('AutomationUtil');
 goog.require('Output');
 goog.require('Output.EventType');
 goog.require('cursors.Cursor');
 goog.require('cvox.ChromeVoxEditableTextBase');
-goog.require('cvox.TabsApiHandler');
 
 // Define types here due to editable_text.js's implicit dependency with
 // ChromeVoxEventWatcher.
 /** @type {Object} */
 cvox.ChromeVoxEventWatcher;
 /** @type {function(boolean)} */
 cvox.ChromeVoxEventWatcher.handleTextChanged;
 /** @type {function()} */
 cvox.ChromeVoxEventWatcher.setUpTextHandler;
 
 goog.scope(function() {
 var AutomationNode = chrome.automation.AutomationNode;
 var Dir = AutomationUtil.Dir;
 var EventType = chrome.automation.EventType;
 
 /**
  * ChromeVox2 background page.
  * @constructor
  */
 Background = function() {
   /**
    * A list of site substring patterns to use with ChromeVox next. Keep these
    * strings relatively specific.
    * @type {!Array.<string>}
    * @private
    */
   this.whitelist_ = ['chromevox_next_test'];
 
   /**
-   * @type {cvox.TabsApiHandler}
-   * @private
-   */
-  this.tabsHandler_ = new cvox.TabsApiHandler(cvox.ChromeVox.tts,
-                                              cvox.ChromeVox.braille,
-                                              cvox.ChromeVox.earcons);
-
-  /**
    * @type {cursors.Range}
    * @private
    */
   this.currentRange_ = null;
 
   /**
    * Whether ChromeVox Next is active.
    * @type {boolean}
    * @private
    */
@@ skipping 17 matching lines @@
     menuEnd: this.onEventDefault,
     menuListValueChanged: this.onEventDefault,
     loadComplete: this.onLoadComplete,
     textChanged: this.onTextOrTextSelectionChanged,
     textSelectionChanged: this.onTextOrTextSelectionChanged,
     valueChanged: this.onEventDefault
   };
 
   // Register listeners for ...
   // Desktop.
-  chrome.automation.getDesktop(this.onGotTree);
+  chrome.automation.getDesktop(this.onGotDesktop);
 
   // Tabs.
   chrome.tabs.onUpdated.addListener(this.onTabUpdated);
 };
 
 Background.prototype = {
   /**
    * Handles chrome.tabs.onUpdated.
    * @param {number} tabId
    * @param {Object} changeInfo
    */
   onTabUpdated: function(tabId, changeInfo) {
     if (changeInfo.status != 'complete')
       return;
     chrome.tabs.get(tabId, function(tab) {
       if (!tab.url)
         return;
 
       var next = this.isWhitelisted_(tab.url);
 
       this.toggleChromeVoxVersion({next: next, classic: !next});
     }.bind(this));
   },
 
   /**
    * Handles all setup once a new automation tree appears.
-   * @param {chrome.automation.AutomationNode} root
+   * @param {chrome.automation.AutomationNode} desktop
    */
-  onGotTree: function(root) {
+  onGotDesktop: function(desktop) {
     // Register all automation event listeners.
     for (var eventType in this.listeners_)
-      root.addEventListener(eventType, this.listeners_[eventType], true);
+      desktop.addEventListener(eventType, this.listeners_[eventType], true);
 
-    if (root.attributes.docLoaded) {
+    var root = desktop.find({role: chrome.automation.RoleType.rootWebArea,
+                             state: {focused: true}});
+    if (root && root.attributes.docLoaded) {
       this.onLoadComplete(
           {target: root, type: chrome.automation.EventType.loadComplete});
     }
   },
 
   /**
    * Handles chrome.commands.onCommand.
    * @param {string} command
    */
   onGotCommand: function(command) {
@@ skipping 225 matching lines @@
   */
   toggleChromeVoxVersion: function(opt_options) {
     if (!opt_options) {
       opt_options = {};
       opt_options.next = !this.active_;
       opt_options.classic = !opt_options.next;
     }
 
     if (opt_options.next) {
       if (!chrome.commands.onCommand.hasListener(this.onGotCommand))
-        chrome.commands.onCommand.addListener(this.onGotCommand);
-
-      if (!this.active_)
-        chrome.automation.getTree(this.onGotTree);
-      this.active_ = true;
+          chrome.commands.onCommand.addListener(this.onGotCommand);
+        this.active_ = true;
     } else {
       if (chrome.commands.onCommand.hasListener(this.onGotCommand))
         chrome.commands.onCommand.removeListener(this.onGotCommand);
-
-      if (this.active_) {
-        for (var eventType in this.listeners_) {
-          this.currentRange_.getStart().getNode().root.removeEventListener(
-              eventType, this.listeners_[eventType], true);
-        }
-      }
       this.active_ = false;
     }
 
     chrome.tabs.query({active: true}, function(tabs) {
       if (opt_options.classic) {
         // This case should do nothing because Classic gets injected by the
         // extension system via our manifest. Once ChromeVox Next is enabled
         // for tabs, re-enable.
         // cvox.ChromeVox.injectChromeVoxIntoTabs(tabs);
       } else {
         tabs.forEach(function(tab) {
           this.disableClassicChromeVox_(tab.id);
         }.bind(this));
       }
     }.bind(this));
   }
 };
 
 /** @type {Background} */
 global.backgroundObj = new Background();
 
 });  // goog.scope