Recovery: Implement focus recovery across root AutomationNodes

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

 // Copyright 2015 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 ChromeVox panel and menus.
  */
 
 goog.provide('Panel');
 
@@ skipping 599 matching lines @@
   if (this.activeMenu_)
     return this.activeMenu_.getCallbackForCurrentItem();
   return null;
 };
 
 /**
  * Close the menus and restore focus to the page. If a menu item's callback
  * was queued, execute it once focus is restored.
  */
 Panel.closeMenusAndRestoreFocus = function() {
-  // Make sure we're not in full-screen mode.
-  window.location = '#';
+  // Watch for the next focus event.
+  var desktop = null;
+  var onFocus = function(evt) {

[dmazzoni, 2016/10/11 17:41:18]

Rather than add and remove a focus listener, what if there
was just a permanent focus listener that calls any pending
callbacks whenever focus lands somewhere other than the
panel?

[David Tseng, 2016/10/11 21:24:32]

I'd like to limit the panel's global event listeners to make sure we never
move/steal focus when we shouldn't.

+    desktop.removeEventListener(chrome.automation.EventType.focus, onFocus);
+    Panel.pendingCallback_ && Panel.pendingCallback_();
+  }.bind(this);
 
-  this.activeMenu_ = null;
+  chrome.automation.getDesktop(function(node) {

[dmazzoni, 2016/10/11 17:41:18]

How about: getDesktop(function(desktop) {

[David Tseng, 2016/10/11 21:24:32]

desktop is used above. I guess I could bind it to onFocus.

+    desktop = node;
+    desktop.addEventListener(chrome.automation.EventType.focus,
+                             onFocus,
+                             true);
 
-  var bkgnd =
-      chrome.extension.getBackgroundPage()['ChromeVoxState']['instance'];
-  bkgnd['endExcursion'](Panel.pendingCallback_);
+    // Make sure we're not in full-screen mode.
+    window.location = '#';
+
+    this.activeMenu_ = null;
+  });
 };
 
 /**
  * Open the tutorial.
  */
 Panel.onTutorial = function() {
-  var bkgnd =
-      chrome.extension.getBackgroundPage()['ChromeVoxState']['instance'];
-  bkgnd['startExcursion']();
-
   // Change the url fragment to 'fullscreen', which signals the native
   // host code to make the window fullscreen, revealing the menus.
   window.location = '#fullscreen';
 
   $('main').style.display = 'none';
   $('menus_background').style.display = 'none';
   $('tutorial').style.display = 'block';
 
   Panel.tutorial_.firstPage();
 };
@@ skipping 26 matching lines @@
 }, false);
 
 window.addEventListener('hashchange', function() {
   if (location.hash == '#fullscreen' || location.hash == '#focus') {
     this.originalStickyState_ = cvox.ChromeVox.isStickyPrefOn;
     cvox.ChromeVox.isStickyPrefOn = false;
   } else {
     cvox.ChromeVox.isStickyPrefOn = this.originalStickyState_;
   }
 }, false);