[Chromoting] Move the onBlur handler from window to the plugin element.

remoting/webapp/client_session.js

 // Copyright (c) 2012 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
  * Class handling creation and teardown of a remoting client session.
  *
  * The ClientSession class controls lifetime of the client plugin
  * object and provides the plugin with the functionality it needs to
@@ skipping 43 matching lines @@
   this.clientJid = '';
   this.sessionId = '';
   /** @type {remoting.ClientPlugin} */
   this.plugin = null;
   this.scaleToFit = false;
   this.logToServer = new remoting.LogToServer();
   this.onStateChange = onStateChange;
   /** @type {remoting.ClientSession} */
   var that = this;
   /** @type {function():void} @private */
-  this.refocusPlugin_ = function() { that.plugin.element().focus(); };
+  this.callPluginLostFocus_ = function() { that.pluginLostFocus_(); };
+  /** @type {function():void} @private */
+  this.callPluginGotFocus_ = function() { that.pluginGotFocus_(); };
 };
 
 // Note that the positive values in both of these enums are copied directly
 // from chromoting_scriptable_object.h and must be kept in sync. The negative
 // values represent states transitions that occur within the web-app that have
 // no corresponding plugin state transition.
 /** @enum {number} */
 remoting.ClientSession.State = {
   CREATED: -3,
   BAD_PLUGIN_VERSION: -2,
@@ skipping 112 matching lines @@
 
 /**
  * Callback function called when the plugin element gets focus.
  */
 remoting.ClientSession.prototype.pluginGotFocus_ = function() {
   // It would be cleaner to send a paste command to the plugin element,
   // but that's not supported.
   /** @type {function(string): void } */
   document.execCommand;
   document.execCommand("paste");
-}
+};
+
+/**
+ * Callback function called when the plugin element loses focus.
+ */
+remoting.ClientSession.prototype.pluginLostFocus_ = function() {
+  if (this.plugin) {
+    // Release all keys to prevent them becoming 'stuck down' on the host.
+    this.plugin.releaseAllKeys();
+    if (this.plugin.element()) {
+      // Focus should stay on the element, not (for example) the toolbar.
+      this.plugin.element().focus();
+    }
+  }
+};
 
 /**
  * Adds <embed> element to |container| and readies the sesion object.
  *
  * @param {Element} container The element to add the plugin to.
  * @param {string} oauth2AccessToken A valid OAuth2 access token.
  */
 remoting.ClientSession.prototype.createPluginAndConnect =
     function(container, oauth2AccessToken) {
   this.plugin = this.createClientPlugin_(container, this.PLUGIN_ID);
 
   this.plugin.element().focus();
-  this.plugin.element().addEventListener('blur', this.refocusPlugin_, false);
 
   /** @type {remoting.ClientSession} */
   var that = this;
   /** @param {boolean} result */
   this.plugin.initialize(function(result) {
       that.onPluginInitialized_(oauth2AccessToken, result);
     });
   this.plugin.element().addEventListener(
-      'focus', function() { that.pluginGotFocus_() }, false);
+      'focus', this.callPluginGotFocus_, false);
+  this.plugin.element().addEventListener(
+      'blur', this.callPluginLostFocus_, false);
 };
 
 /**
  * @param {string} oauth2AccessToken
  * @param {boolean} initialized
  */
 remoting.ClientSession.prototype.onPluginInitialized_ =
     function(oauth2AccessToken, initialized) {
   if (!initialized) {
     console.error('ERROR: remoting plugin not loaded');
@@ skipping 39 matching lines @@
 /**
  * Deletes the <embed> element from the container, without sending a
  * session_terminate request.  This is to be called when the session was
  * disconnected by the Host.
  *
  * @return {void} Nothing.
  */
 remoting.ClientSession.prototype.removePlugin = function() {
   if (this.plugin) {
     this.plugin.element().removeEventListener(
-        'blur', this.refocusPlugin_, false);
+        'focus', this.callPluginGotFocus_, false);
+    this.plugin.element().removeEventListener(
+        'blur', this.callPluginLostFocus_, false);
     this.plugin.cleanup();
     this.plugin = null;
   }
 };
 
 /**
  * Deletes the <embed> element from the container and disconnects.
  *
  * @return {void} Nothing.
  */
@@ skipping 222 matching lines @@
 };
 
 /**
  * Logs statistics.
  *
  * @param {remoting.ClientSession.PerfStats} stats
  */
 remoting.ClientSession.prototype.logStatistics = function(stats) {
   this.logToServer.logStatistics(stats, this.mode);
 };