/**
* @license
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
goog.provide('shaka.cast.CastSender');
goog.require('goog.asserts');
goog.require('shaka.cast.CastUtils');
goog.require('shaka.log');
goog.require('shaka.util.Error');
goog.require('shaka.util.FakeEvent');
goog.require('shaka.util.IDestroyable');
goog.require('shaka.util.PublicPromise');
/**
* @constructor
* @struct
* @param {string} receiverAppId The ID of the cast receiver application.
* @param {function()} onStatusChanged A callback invoked when the cast status
* changes.
* @param {function()} onFirstCastStateUpdate A callback invoked when the
* an "update" event has been received for the first time.
* @param {function(string, !shaka.util.FakeEvent)} onRemoteEvent A callback
* invoked with target name and event when a remote event is received.
* @param {function()} onResumeLocal A callback invoked when the local player
* should resume playback. Called before cached remote state is wiped.
* @param {function()} onInitStateRequired A callback to get local player's.
* state. Invoked when casting is initiated from Chrome's cast button.
* @implements {shaka.util.IDestroyable}
*/
shaka.cast.CastSender =
function(receiverAppId, onStatusChanged, onFirstCastStateUpdate,
onRemoteEvent, onResumeLocal, onInitStateRequired) {
/** @private {string} */
this.receiverAppId_ = receiverAppId;
/** @private {?function()} */
this.onStatusChanged_ = onStatusChanged;
/** @private {?function()} */
this.onFirstCastStateUpdate_ = onFirstCastStateUpdate;
/** @private {boolean} */
this.hasJoinedExistingSession_ = false;
/** @private {?function(string, !shaka.util.FakeEvent)} */
this.onRemoteEvent_ = onRemoteEvent;
/** @private {?function()} */
this.onResumeLocal_ = onResumeLocal;
/** @private {?function()} */
this.onInitStateRequired_ = onInitStateRequired;
/** @private {boolean} */
this.apiReady_ = false;
/** @private {boolean} */
this.isCasting_ = false;
/** @private {string} */
this.receiverName_ = '';
/** @private {Object} */
this.appData_ = null;
/** @private {?function()} */
this.onConnectionStatusChangedBound_ =
this.onConnectionStatusChanged_.bind(this);
/** @private {?function(string, string)} */
this.onMessageReceivedBound_ = this.onMessageReceived_.bind(this);
/** @private {Object} */
this.cachedProperties_ = {
'video': {},
'player': {}
};
/** @private {number} */
this.nextAsyncCallId_ = 0;
/** @private {Object.<string, !shaka.util.PublicPromise>} */
this.asyncCallPromises_ = {};
/** @private {shaka.util.PublicPromise} */
this.castPromise_ = null;
};
/** @private {boolean} */
shaka.cast.CastSender.hasReceivers_ = false;
/** @private {chrome.cast.Session} */
shaka.cast.CastSender.session_ = null;
/** @override */
shaka.cast.CastSender.prototype.destroy = function() {
this.rejectAllPromises_();
if (shaka.cast.CastSender.session_) {
this.removeListeners_();
// Don't leave the session, so that this session can be re-used later if
// necessary.
}
this.onStatusChanged_ = null;
this.onRemoteEvent_ = null;
this.onResumeLocal_ = null;
this.apiReady_ = false;
this.isCasting_ = false;
this.appData_ = null;
this.cachedProperties_ = null;
this.asyncCallPromises_ = null;
this.castPromise_ = null;
this.onConnectionStatusChangedBound_ = null;
this.onMessageReceivedBound_ = null;
return Promise.resolve();
};
/**
* @return {boolean} True if the cast API is available.
*/
shaka.cast.CastSender.prototype.apiReady = function() {
return this.apiReady_;
};
/**
* @return {boolean} True if there are receivers.
*/
shaka.cast.CastSender.prototype.hasReceivers = function() {
return shaka.cast.CastSender.hasReceivers_;
};
/**
* @return {boolean} True if we are currently casting.
*/
shaka.cast.CastSender.prototype.isCasting = function() {
return this.isCasting_;
};
/**
* @return {string} The name of the Cast receiver device, if isCasting().
*/
shaka.cast.CastSender.prototype.receiverName = function() {
return this.receiverName_;
};
/**
* @return {boolean} True if we have a cache of remote properties from the
* receiver.
*/
shaka.cast.CastSender.prototype.hasRemoteProperties = function() {
return Object.keys(this.cachedProperties_['video']).length != 0;
};
/**
* Initialize the Cast API.
*/
shaka.cast.CastSender.prototype.init = function() {
// Check for the cast extension.
if (!window.chrome || !chrome.cast || !chrome.cast.isAvailable) {
// Not available yet, so wait to be notified if/when it is available.
window.__onGCastApiAvailable = (function(loaded) {
if (loaded) {
this.init();
}
}).bind(this);
return;
}
// The API is now available.
delete window.__onGCastApiAvailable;
this.apiReady_ = true;
this.onStatusChanged_();
var sessionRequest = new chrome.cast.SessionRequest(this.receiverAppId_);
var apiConfig = new chrome.cast.ApiConfig(sessionRequest,
this.onExistingSessionJoined_.bind(this),
this.onReceiverStatusChanged_.bind(this),
'origin_scoped');
// TODO: have never seen this fail. when would it and how should we react?
chrome.cast.initialize(apiConfig,
function() { shaka.log.debug('CastSender: init'); },
function(error) { shaka.log.error('CastSender: init error', error); });
if (shaka.cast.CastSender.hasReceivers_) {
// Fire a fake cast status change, to simulate the update that
// would be fired normally.
// This is after a brief delay, to give users a chance to add event
// listeners.
setTimeout(this.onStatusChanged_.bind(this), 20);
}
var oldSession = shaka.cast.CastSender.session_;
if (oldSession && oldSession.status != chrome.cast.SessionStatus.STOPPED) {
// The old session still exists, so re-use it.
shaka.log.debug('CastSender: re-using existing connection');
this.onExistingSessionJoined_(oldSession);
} else {
// The session has been canceled in the meantime, so ignore it.
shaka.cast.CastSender.session_ = null;
}
};
/**
* Set application-specific data.
*
* @param {Object} appData Application-specific data to relay to the receiver.
*/
shaka.cast.CastSender.prototype.setAppData = function(appData) {
this.appData_ = appData;
if (this.isCasting_) {
this.sendMessage_({
'type': 'appData',
'appData': this.appData_
});
}
};
/**
* @param {shaka.cast.CastUtils.InitStateType} initState Video and player state
* to be sent to the receiver.
* @return {!Promise} Resolved when connected to a receiver. Rejected if the
* connection fails or is canceled by the user.
*/
shaka.cast.CastSender.prototype.cast = function(initState) {
if (!this.apiReady_) {
return Promise.reject(new shaka.util.Error(
shaka.util.Error.Severity.RECOVERABLE,
shaka.util.Error.Category.CAST,
shaka.util.Error.Code.CAST_API_UNAVAILABLE));
}
if (!shaka.cast.CastSender.hasReceivers_) {
return Promise.reject(new shaka.util.Error(
shaka.util.Error.Severity.RECOVERABLE,
shaka.util.Error.Category.CAST,
shaka.util.Error.Code.NO_CAST_RECEIVERS));
}
if (this.isCasting_) {
return Promise.reject(new shaka.util.Error(
shaka.util.Error.Severity.RECOVERABLE,
shaka.util.Error.Category.CAST,
shaka.util.Error.Code.ALREADY_CASTING));
}
this.castPromise_ = new shaka.util.PublicPromise();
chrome.cast.requestSession(
this.onSessionInitiated_.bind(this, initState),
this.onConnectionError_.bind(this));
return this.castPromise_;
};
/**
* Shows user a cast dialog where they can choose to stop
* casting. Relies on Chrome to perform disconnect if they do.
* Doesn't do anything if not connected.
*/
shaka.cast.CastSender.prototype.showDisconnectDialog = function() {
if (!this.isCasting_) {
return;
}
var initState = this.onInitStateRequired_();
chrome.cast.requestSession(
this.onSessionInitiated_.bind(this, initState),
this.onConnectionError_.bind(this));
};
/**
* Forces the receiver app to shut down by disconnecting. Does nothing if not
* connected.
*/
shaka.cast.CastSender.prototype.forceDisconnect = function() {
if (!this.isCasting_) {
return;
}
this.rejectAllPromises_();
if (shaka.cast.CastSender.session_) {
this.removeListeners_();
shaka.cast.CastSender.session_.stop(function() {}, function() {});
shaka.cast.CastSender.session_ = null;
}
};
/**
* Getter for properties of remote objects.
* @param {string} targetName
* @param {string} property
* @return {?}
*/
shaka.cast.CastSender.prototype.get = function(targetName, property) {
goog.asserts.assert(targetName == 'video' || targetName == 'player',
'Unexpected target name');
var CastUtils = shaka.cast.CastUtils;
if (targetName == 'video') {
if (CastUtils.VideoVoidMethods.indexOf(property) >= 0) {
return this.remoteCall_.bind(this, targetName, property);
}
} else if (targetName == 'player') {
if (CastUtils.PlayerGetterMethodsThatRequireLive[property]) {
var isLive = this.get('player', 'isLive')();
goog.asserts.assert(isLive,
property + ' should be called on a live stream!');
// If the property shouldn't exist, return a fake function so that the
// user doesn't call an undefined function and get a second error.
if (!isLive)
return function() { return undefined; };
}
if (CastUtils.PlayerVoidMethods.indexOf(property) >= 0) {
return this.remoteCall_.bind(this, targetName, property);
}
if (CastUtils.PlayerPromiseMethods.indexOf(property) >= 0) {
return this.remoteAsyncCall_.bind(this, targetName, property);
}
if (CastUtils.PlayerGetterMethods[property]) {
return this.propertyGetter_.bind(this, targetName, property);
}
}
return this.propertyGetter_(targetName, property);
};
/**
* Setter for properties of remote objects.
* @param {string} targetName
* @param {string} property
* @param {?} value
*/
shaka.cast.CastSender.prototype.set = function(targetName, property, value) {
goog.asserts.assert(targetName == 'video' || targetName == 'player',
'Unexpected target name');
this.cachedProperties_[targetName][property] = value;
this.sendMessage_({
'type': 'set',
'targetName': targetName,
'property': property,
'value': value
});
};
/**
* @param {shaka.cast.CastUtils.InitStateType} initState
* @param {chrome.cast.Session} session
* @private
*/
shaka.cast.CastSender.prototype.onSessionInitiated_ =
function(initState, session) {
shaka.log.debug('CastSender: onSessionInitiated');
this.onSessionCreated_(session);
this.sendMessage_({
'type': 'init',
'initState': initState,
'appData': this.appData_
});
this.castPromise_.resolve();
};
/**
* @param {chrome.cast.Error} error
* @private
*/
shaka.cast.CastSender.prototype.onConnectionError_ = function(error) {
// Default error code:
var code = shaka.util.Error.Code.UNEXPECTED_CAST_ERROR;
switch (error.code) {
case 'cancel':
code = shaka.util.Error.Code.CAST_CANCELED_BY_USER;
break;
case 'timeout':
code = shaka.util.Error.Code.CAST_CONNECTION_TIMED_OUT;
break;
case 'receiver_unavailable':
code = shaka.util.Error.Code.CAST_RECEIVER_APP_UNAVAILABLE;
break;
}
this.castPromise_.reject(new shaka.util.Error(
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.CAST,
code,
error));
};
/**
* @param {string} targetName
* @param {string} property
* @return {?}
* @private
*/
shaka.cast.CastSender.prototype.propertyGetter_ =
function(targetName, property) {
goog.asserts.assert(targetName == 'video' || targetName == 'player',
'Unexpected target name');
return this.cachedProperties_[targetName][property];
};
/**
* @param {string} targetName
* @param {string} methodName
* @private
*/
shaka.cast.CastSender.prototype.remoteCall_ =
function(targetName, methodName) {
goog.asserts.assert(targetName == 'video' || targetName == 'player',
'Unexpected target name');
var args = Array.prototype.slice.call(arguments, 2);
this.sendMessage_({
'type': 'call',
'targetName': targetName,
'methodName': methodName,
'args': args
});
};
/**
* @param {string} targetName
* @param {string} methodName
* @return {!Promise}
* @private
*/
shaka.cast.CastSender.prototype.remoteAsyncCall_ =
function(targetName, methodName) {
goog.asserts.assert(targetName == 'video' || targetName == 'player',
'Unexpected target name');
var args = Array.prototype.slice.call(arguments, 2);
var p = new shaka.util.PublicPromise();
var id = this.nextAsyncCallId_.toString();
this.nextAsyncCallId_++;
this.asyncCallPromises_[id] = p;
this.sendMessage_({
'type': 'asyncCall',
'targetName': targetName,
'methodName': methodName,
'args': args,
'id': id
});
return p;
};
/**
* @param {chrome.cast.Session} session
* @private
*/
shaka.cast.CastSender.prototype.onExistingSessionJoined_ = function(session) {
shaka.log.debug('CastSender: onExistingSessionJoined');
var initState = this.onInitStateRequired_();
this.castPromise_ = new shaka.util.PublicPromise();
this.hasJoinedExistingSession_ = true;
this.onSessionInitiated_(initState, session);
};
/**
* @param {string} availability
* @private
*/
shaka.cast.CastSender.prototype.onReceiverStatusChanged_ =
function(availability) {
// The cast extension is telling us whether there are any cast receiver
// devices available.
shaka.log.debug('CastSender: receiver status', availability);
shaka.cast.CastSender.hasReceivers_ = availability == 'available';
this.onStatusChanged_();
};
/**
* @param {chrome.cast.Session} session
* @private
*/
shaka.cast.CastSender.prototype.onSessionCreated_ = function(session) {
shaka.cast.CastSender.session_ = session;
session.addUpdateListener(this.onConnectionStatusChangedBound_);
session.addMessageListener(shaka.cast.CastUtils.SHAKA_MESSAGE_NAMESPACE,
this.onMessageReceivedBound_);
this.onConnectionStatusChanged_();
};
/**
* @private
*/
shaka.cast.CastSender.prototype.removeListeners_ = function() {
var session = shaka.cast.CastSender.session_;
session.removeUpdateListener(this.onConnectionStatusChangedBound_);
session.removeMessageListener(shaka.cast.CastUtils.SHAKA_MESSAGE_NAMESPACE,
this.onMessageReceivedBound_);
};
/**
* @private
*/
shaka.cast.CastSender.prototype.onConnectionStatusChanged_ = function() {
var connected = shaka.cast.CastSender.session_ ?
shaka.cast.CastSender.session_.status == 'connected' :
false;
shaka.log.debug('CastSender: connection status', connected);
if (this.isCasting_ && !connected) {
// Tell CastProxy to transfer state back to local player.
this.onResumeLocal_();
// Clear whatever we have cached.
for (var targetName in this.cachedProperties_) {
this.cachedProperties_[targetName] = {};
}
this.rejectAllPromises_();
}
this.isCasting_ = connected;
this.receiverName_ = connected ?
shaka.cast.CastSender.session_.receiver.friendlyName :
'';
this.onStatusChanged_();
};
/**
* Reject any async call promises that are still pending.
* @private
*/
shaka.cast.CastSender.prototype.rejectAllPromises_ = function() {
for (var id in this.asyncCallPromises_) {
var p = this.asyncCallPromises_[id];
delete this.asyncCallPromises_[id];
// Reject pending async operations as if they were interrupted.
// At the moment, load() is the only async operation we are worried
// about.
p.reject(new shaka.util.Error(
shaka.util.Error.Severity.RECOVERABLE,
shaka.util.Error.Category.PLAYER,
shaka.util.Error.Code.LOAD_INTERRUPTED));
}
};
/**
* Since this method is in the compiled library, make sure all messages are
* read with quoted properties.
* @param {string} namespace
* @param {string} serialized
* @private
*/
shaka.cast.CastSender.prototype.onMessageReceived_ =
function(namespace, serialized) {
var message = shaka.cast.CastUtils.deserialize(serialized);
shaka.log.v2('CastSender: message', message);
switch (message['type']) {
case 'event': {
var targetName = message['targetName'];
var event = message['event'];
var fakeEvent = new shaka.util.FakeEvent(event['type'], event);
this.onRemoteEvent_(targetName, fakeEvent);
break;
}
case 'update': {
var update = message['update'];
for (var targetName in update) {
var target = this.cachedProperties_[targetName] || {};
for (var property in update[targetName]) {
target[property] = update[targetName][property];
}
}
if (this.hasJoinedExistingSession_) {
this.onFirstCastStateUpdate_();
this.hasJoinedExistingSession_ = false;
}
break;
}
case 'asyncComplete': {
var id = message['id'];
var error = message['error'];
var p = this.asyncCallPromises_[id];
delete this.asyncCallPromises_[id];
goog.asserts.assert(p, 'Unexpected async id');
if (!p) break;
if (error) {
// This is a hacky way to reconstruct the serialized error.
var reconstructedError = new shaka.util.Error(
error.severity, error.category, error.code);
for (var k in error) {
(/** @type {Object} */(reconstructedError))[k] = error[k];
}
p.reject(reconstructedError);
} else {
p.resolve();
}
break;
}
}
};
/**
* Since this method is in the compiled library, make sure all messages passed
* in here were created with quoted property names.
* @param {!Object} message
* @private
*/
shaka.cast.CastSender.prototype.sendMessage_ = function(message) {
var serialized = shaka.cast.CastUtils.serialize(message);
// TODO: have never seen this fail. When would it and how should we react?
var session = shaka.cast.CastSender.session_;
session.sendMessage(shaka.cast.CastUtils.SHAKA_MESSAGE_NAMESPACE,
serialized,
function() {}, // success callback
shaka.log.error); // error callback
};