Video Player: Use Google Cast API extension instead of deprecated way

ui/file_manager/video_player/js/cast/caster.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.
 
 'use strict';
 
-/**
- * The instance of cast api.
- * @type {cast.ExtensionApi}
- */
-var castApi = null;
+// This hack prevents a bug on the cast extension.
+// TODO(yoshiki): Remove this once the cast extension supports Chrome apps.
+// Although localStorage in Chrome app is not supported, but it's used in the
+// cast extension. This line prevents an exception on using localStorage.
+window.__defineGetter__('localStorage', function() { return {}; });
 
 /**
  * @type {string}
  * @const
  */
 var CAST_COMMAND_LINE_FLAG = 'enable-video-player-chromecast-support';
 
+// THIS IS A TEST APP.
+// TODO(yoshiki): Fix this before launch.
+var APPLICATION_ID = '214CC863';
+
 chrome.commandLinePrivate.hasSwitch(CAST_COMMAND_LINE_FLAG, function(result) {
   if (!result)
     return;
 
-  CastExtensionDiscoverer.findInstalledExtension(onCastExtensionFound);
+  ensureLoad(initializeApi);
 });
 
-function onCastExtensionFound(extensionId) {
-  if (!extensionId) {
-    console.info('Cast extention is not found.');
-    return;
+/**
+ * Executes the given callback after the cast extension is initialized.
+ * @param {function} callback Callback (executed asynchronously).
+ */
+function ensureLoad(callback) {
+  if(!chrome.cast || !chrome.cast.isAvailable) {
+    var checkTimer = setTimeout(function() {
+      console.error('Either "Google Cast API" or "Google Cast" extension ' +
+                    'seems not to be installed?');
+    }, 5000);
+
+    window['__onGCastApiAvailable'] = function(loaded, errorInfo) {
+      if (loaded) {
+        callback();
+        clearTimeout(chcekTimer);
+      } else {
+        console.error(errorInfo);
+      }
+    }
+  } else {
+    setTimeout(callback);  // Runs asynchronously.
   }
-
-  var api = document.createElement('script');
-  api.src = 'chrome-extension://' + extensionId + '/api_script.js';
-  api.onload = function() {
-    initializeCast(extensionId);
-  };
-  api.onerror = function() {
-    console.error('api_script.js load failed.');
-  };
-  document.body.appendChild(api);
-};
-
-function initializeCast(extensionId) {
-  loadCastExtensionApi();
-
-  castApi = new cast.ExtensionApi(extensionId);
-  castApi.addReceiverListener('ChromeCast', onReceiverUpdate);
 }
 
-function onReceiverUpdate(receivers) {
-  player.setCastList(receivers);
+function initializeApi() {

[hirono, 2014/07/23 04:37:31]

nit: missing jsdoc.

[yoshiki, 2014/07/23 05:07:32]

Done.

+  var onSession = function() {
+    // TODO(yoshiki): Implement this.
+  };
+
+  var onInitSuccess = function() {
+    // TODO(yoshiki): Implement this.
+  };
+
+  /**
+   * @param {chrome.cast.Error} error
+   */
+  var onError = function(error) {
+    console.error('Error on Cast initialization.', error);
+  };
+
+  var sessionRequest = new chrome.cast.SessionRequest(APPLICATION_ID);
+  var apiConfig = new chrome.cast.ApiConfig(sessionRequest,
+                                            onSession,
+                                            onReceiver);
+  chrome.cast.initialize(apiConfig, onInitSuccess, onError);
 }
+
+/**
+ * @param {chrome.cast.ReceiverAvailability} availability Availability of casts.
+ * @param {Array.<Object>} receivers List of casts.
+ */
+function onReceiver(availability, receivers) {
+  if (availability === chrome.cast.ReceiverAvailability.AVAILABLE) {
+    player.setCastList(receivers);
+  } else if (availability == chrome.cast.ReceiverAvailability.UNAVAILABLE) {
+    player.setCastList([]);
+  } else {
+    console.error('Unexpected response in onReceiver.', arguments);
+    player.setCastList([]);
+  }
+}