CastExtensionHandler for Chromoting Webapp

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
  * establish connection. Specifically it:
  *  - Delivers incoming/outgoing signaling messages,
  *  - Adjusts plugin size and position when destop resolution changes,
  *
  * This class should not access the plugin directly, instead it should
  * do it through ClientPlugin class which abstracts plugin version
  * differences.
  */
 
 'use strict';
 
 /** @suppress {duplicate} */
 var remoting = remoting || {};
 
 /**
+ * True if Cast capability is supported.
+ *
+ * @type {boolean}
+ */
+remoting.enableCast = false;
+
+/**
  * @param {HTMLElement} container Container element for the client view.
  * @param {string} hostDisplayName A human-readable name for the host.
  * @param {string} accessCode The IT2Me access code. Blank for Me2Me.
  * @param {function(boolean, function(string): void): void} fetchPin
  *     Called by Me2Me connections when a PIN needs to be obtained
  *     interactively.
  * @param {function(string, string, string,
  *                  function(string, string): void): void}
  *     fetchThirdPartyToken Called by Me2Me connections when a third party
  *     authentication token must be obtained.
@@ skipping 123 matching lines @@
   this.resizeToClientButton_ =
       document.getElementById('screen-resize-to-client');
   /** @type {HTMLElement} @private */
   this.shrinkToFitButton_ = document.getElementById('screen-shrink-to-fit');
   /** @type {HTMLElement} @private */
   this.fullScreenButton_ = document.getElementById('toggle-full-screen');
 
   /** @type {remoting.GnubbyAuthHandler} @private */
   this.gnubbyAuthHandler_ = null;
 
+  /** @type {remoting.CastExtensionHandler} @private */
+  this.castExtensionHandler_ = null;
+
   if (this.mode_ == remoting.ClientSession.Mode.IT2ME) {
     // Resize-to-client is not supported for IT2Me hosts.
     this.resizeToClientButton_.hidden = true;
   } else {
     this.resizeToClientButton_.hidden = false;
   }
 
   this.fullScreenButton_.addEventListener(
       'click', this.callToggleFullScreen_, false);
   this.defineEvents(Object.keys(remoting.ClientSession.Events));
@@ skipping 187 matching lines @@
  * Set of capabilities for which hasCapability_() can be used to test.
  *
  * @enum {string}
  */
 remoting.ClientSession.Capability = {
   // When enabled this capability causes the client to send its screen
   // resolution to the host once connection has been established. See
   // this.plugin_.notifyClientResolution().
   SEND_INITIAL_RESOLUTION: 'sendInitialResolution',
   RATE_LIMIT_RESIZE_REQUESTS: 'rateLimitResizeRequests',
-  VIDEO_RECORDER: 'videoRecorder'
+  VIDEO_RECORDER: 'videoRecorder',
+  CAST: 'casting'
 };
 
 /**
  * The set of capabilities negotiated between the client and host.
  * @type {Array.<string>}
  * @private
  */
 remoting.ClientSession.prototype.capabilities_ = null;
 
 /**
@@ skipping 193 matching lines @@
   };
 
   this.plugin_.onConnectionStatusUpdateHandler =
       this.onConnectionStatusUpdate_.bind(this);
   this.plugin_.onConnectionReadyHandler = this.onConnectionReady_.bind(this);
   this.plugin_.onDesktopSizeUpdateHandler =
       this.onDesktopSizeChanged_.bind(this);
   this.plugin_.onSetCapabilitiesHandler = this.onSetCapabilities_.bind(this);
   this.plugin_.onGnubbyAuthHandler = this.processGnubbyAuthMessage_.bind(this);
   this.plugin_.updateMouseCursorImage = this.updateMouseCursorImage_.bind(this);
+  this.plugin_.onCastExtensionHandler =
+      this.processCastExtensionMessage_.bind(this);
   this.initiateConnection_();
 };
 
 /**
  * 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.
  */
@@ skipping 502 matching lines @@
       console.log('Suppressing host-offline error.');
       state = remoting.ClientSession.State.CONNECTION_CANCELED;
     }
   } else if (oldState == remoting.ClientSession.State.CONNECTED &&
              this.state_ == remoting.ClientSession.State.FAILED) {
     state = remoting.ClientSession.State.CONNECTION_DROPPED;
   }
   this.logToServer.logClientSessionStateChange(state, this.error_, this.mode_);
   if (this.state_ == remoting.ClientSession.State.CONNECTED) {
     this.createGnubbyAuthHandler_();
+    this.createCastExtensionHandler_();
   }
 
   this.raiseEvent(remoting.ClientSession.Events.stateChanged,
     new remoting.ClientSession.StateEvent(newState, oldState)
   );
 };
 
 /**
  * This is a callback that gets called when the window is resized.
  *
@@ skipping 449 matching lines @@
  * @return {{top: number, left:number}} The top-left corner of the plugin.
  */
 remoting.ClientSession.prototype.getPluginPositionForTesting = function() {
   var plugin = this.plugin_.element();
   var style = plugin.style;
   return {
     top: parseFloat(style.marginTop),
     left: parseFloat(style.marginLeft)
   };
 };
+
+/**
+ * Send a Cast extension message to the host.
+ * @param {Object} data The cast message data.
+ */
+remoting.ClientSession.prototype.sendCastExtensionMessage = function(data) {
+  if (!this.plugin_)
+    return;
+  this.plugin_.sendClientMessage('cast_message', JSON.stringify(data));
+};
+
+/**
+ * Process a remote Cast extension message from the host.
+ * @param {string} data Remote cast extension data message.
+ * @private
+ */
+remoting.ClientSession.prototype.processCastExtensionMessage_ = function(data) {
+  if (this.castExtensionHandler_) {
+    try {
+      this.castExtensionHandler_.onMessage(data);
+    } catch (err) {
+      console.error('Failed to process cast message: ',
+          /** @type {*} */ (err));
+    }
+  } else {
+    console.error('Received unexpected cast message');
+  }
+};
+
+/**
+ * Create a CastExtensionHandler and inform the host that cast extension
+ * is supported.
+ * @private
+ */
+remoting.ClientSession.prototype.createCastExtensionHandler_ = function() {
+  if (remoting.enableCast && this.mode_ == remoting.ClientSession.Mode.ME2ME) {
+    this.castExtensionHandler_ = new remoting.CastExtensionHandler(this);
+  }
+};
+