/*! @license
* Shaka Player
* Copyright 2016 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
goog.provide('shaka.cast.CastProxy');
goog.require('goog.asserts');
goog.require('shaka.Player');
goog.require('shaka.cast.CastSender');
goog.require('shaka.cast.CastUtils');
goog.require('shaka.log');
goog.require('shaka.util.Error');
goog.require('shaka.util.EventManager');
goog.require('shaka.util.FakeEvent');
goog.require('shaka.util.FakeEventTarget');
goog.require('shaka.util.IDestroyable');
/**
* @event shaka.cast.CastProxy.CastStatusChangedEvent
* @description Fired when cast status changes. The status change will be
* reflected in canCast() and isCasting().
* @property {string} type
* 'caststatuschanged'
* @exportDoc
*/
/**
* @summary A proxy to switch between local and remote playback for Chromecast
* in a way that is transparent to the app's controls.
*
* @implements {shaka.util.IDestroyable}
* @export
*/
shaka.cast.CastProxy = class extends shaka.util.FakeEventTarget {
/**
* @param {!HTMLMediaElement} video The local video element associated with
* the local Player instance.
* @param {!shaka.Player} player A local Player instance.
* @param {string} receiverAppId The ID of the cast receiver application.
* If blank, casting will not be available, but the proxy will still
* function otherwise.
*/
constructor(video, player, receiverAppId) {
super();
/** @private {HTMLMediaElement} */
this.localVideo_ = video;
/** @private {shaka.Player} */
this.localPlayer_ = player;
/** @private {Object} */
this.videoProxy_ = null;
/** @private {Object} */
this.playerProxy_ = null;
/** @private {shaka.util.FakeEventTarget} */
this.videoEventTarget_ = null;
/** @private {shaka.util.FakeEventTarget} */
this.playerEventTarget_ = null;
/** @private {shaka.util.EventManager} */
this.eventManager_ = null;
/** @private {string} */
this.receiverAppId_ = receiverAppId;
/** @private {!Map} */
this.compiledToExternNames_ = new Map();
/** @private {shaka.cast.CastSender} */
this.sender_ = new shaka.cast.CastSender(
receiverAppId,
() => this.onCastStatusChanged_(),
() => this.onFirstCastStateUpdate_(),
(targetName, event) => this.onRemoteEvent_(targetName, event),
() => this.onResumeLocal_(),
() => this.getInitState_());
this.init_();
}
/**
* Destroys the proxy and the underlying local Player.
*
* @param {boolean=} forceDisconnect If true, force the receiver app to shut
* down by disconnecting. Does nothing if not connected.
* @override
* @export
*/
destroy(forceDisconnect) {
if (forceDisconnect) {
this.sender_.forceDisconnect();
}
if (this.eventManager_) {
this.eventManager_.release();
this.eventManager_ = null;
}
const waitFor = [];
if (this.localPlayer_) {
waitFor.push(this.localPlayer_.destroy());
this.localPlayer_ = null;
}
if (this.sender_) {
waitFor.push(this.sender_.destroy());
this.sender_ = null;
}
this.localVideo_ = null;
this.videoProxy_ = null;
this.playerProxy_ = null;
return Promise.all(waitFor);
}
/**
* Get a proxy for the video element that delegates to local and remote video
* elements as appropriate.
*
* @suppress {invalidCasts} to cast proxy Objects to unrelated types
* @return {!HTMLMediaElement}
* @export
*/
getVideo() {
return /** @type {!HTMLMediaElement} */(this.videoProxy_);
}
/**
* Get a proxy for the Player that delegates to local and remote Player
* objects as appropriate.
*
* @suppress {invalidCasts} to cast proxy Objects to unrelated types
* @return {!shaka.Player}
* @export
*/
getPlayer() {
return /** @type {!shaka.Player} */(this.playerProxy_);
}
/**
* @return {boolean} True if the cast API is available and there are
* receivers.
* @export
*/
canCast() {
return this.sender_.apiReady() && this.sender_.hasReceivers();
}
/**
* @return {boolean} True if we are currently casting.
* @export
*/
isCasting() {
return this.sender_.isCasting();
}
/**
* @return {string} The name of the Cast receiver device, if isCasting().
* @export
*/
receiverName() {
return this.sender_.receiverName();
}
/**
* @return {!Promise} Resolved when connected to a receiver. Rejected if the
* connection fails or is canceled by the user.
* @export
*/
async cast() {
const initState = this.getInitState_();
// TODO: transfer manually-selected tracks?
// TODO: transfer side-loaded text tracks?
await this.sender_.cast(initState);
if (!this.localPlayer_) {
// We've already been destroyed.
return;
}
// Unload the local manifest when casting succeeds.
await this.localPlayer_.unload();
}
/**
* Set application-specific data.
*
* @param {Object} appData Application-specific data to relay to the receiver.
* @export
*/
setAppData(appData) {
this.sender_.setAppData(appData);
}
/**
* Show a dialog where user can choose to disconnect from the cast connection.
* @export
*/
suggestDisconnect() {
this.sender_.showDisconnectDialog();
}
/**
* Force the receiver app to shut down by disconnecting.
* @export
*/
forceDisconnect() {
this.sender_.forceDisconnect();
}
/**
* @param {string} newAppId
* @export
*/
async changeReceiverId(newAppId) {
if (newAppId == this.receiverAppId_) {
// Nothing to change
return;
}
this.receiverAppId_ = newAppId;
// Destroy the old sender
this.sender_.forceDisconnect();
await this.sender_.destroy();
this.sender_ = null;
// Create the new one
this.sender_ = new shaka.cast.CastSender(
newAppId,
() => this.onCastStatusChanged_(),
() => this.onFirstCastStateUpdate_(),
(targetName, event) => this.onRemoteEvent_(targetName, event),
() => this.onResumeLocal_(),
() => this.getInitState_());
this.sender_.init();
}
/**
* Initialize the Proxies and the Cast sender.
* @private
*/
init_() {
this.sender_.init();
this.eventManager_ = new shaka.util.EventManager();
for (const name of shaka.cast.CastUtils.VideoEvents) {
this.eventManager_.listen(this.localVideo_, name,
(event) => this.videoProxyLocalEvent_(event));
}
for (const key in shaka.Player.EventName) {
const name = shaka.Player.EventName[key];
this.eventManager_.listen(this.localPlayer_, name,
(event) => this.playerProxyLocalEvent_(event));
}
// We would like to use Proxy here, but it is not supported on Safari.
this.videoProxy_ = {};
for (const k in this.localVideo_) {
Object.defineProperty(this.videoProxy_, k, {
configurable: false,
enumerable: true,
get: () => this.videoProxyGet_(k),
set: (value) => { this.videoProxySet_(k, value); },
});
}
this.playerProxy_ = {};
this.iterateOverPlayerMethods_((name, method) => {
goog.asserts.assert(this.playerProxy_, 'Must have player proxy!');
Object.defineProperty(this.playerProxy_, name, {
configurable: false,
enumerable: true,
get: () => this.playerProxyGet_(name),
});
});
if (COMPILED) {
this.mapCompiledToUncompiledPlayerMethodNames_();
}
this.videoEventTarget_ = new shaka.util.FakeEventTarget();
this.videoEventTarget_.dispatchTarget =
/** @type {EventTarget} */(this.videoProxy_);
this.playerEventTarget_ = new shaka.util.FakeEventTarget();
this.playerEventTarget_.dispatchTarget =
/** @type {EventTarget} */(this.playerProxy_);
}
/**
* Maps compiled to uncompiled player names so we can figure out
* which method to call in compiled build, while casting.
* @private
*/
mapCompiledToUncompiledPlayerMethodNames_() {
// In compiled mode, UI tries to access player methods
// by their internal renamed names, but the proxy object doesn't know about
// those.
// See https://github.com/google/shaka-player/issues/2130 for details.
const methodsToNames = new Map();
this.iterateOverPlayerMethods_((name, method) => {
if (methodsToNames.has(method)) {
// If two method names, point to the same method, add them to the
// map as aliases of each other.
const name2 = methodsToNames.get(method);
// Assumes that the compiled name is shorter
if (name.length < name2.length) {
this.compiledToExternNames_.set(name, name2);
} else {
this.compiledToExternNames_.set(name2, name);
}
} else {
methodsToNames.set(method, name);
}
});
}
/**
* Iterates over all of the methods of the player, including inherited methods
* from FakeEventTarget.
* @param {function(string, function())} operation
* @private
*/
iterateOverPlayerMethods_(operation) {
goog.asserts.assert(this.localPlayer_, 'Must have player!');
const player = /** @type {!Object} */ (this.localPlayer_);
// Avoid accessing any over-written methods in the prototype chain.
const seenNames = new Set();
/**
* @param {string} name
* @return {boolean}
*/
function shouldAddToTheMap(name) {
if (name == 'constructor') {
// Don't proxy the constructor.
return false;
}
const method = /** @type {Object} */(player)[name];
if (typeof method != 'function') {
// Don't proxy non-methods.
return false;
}
// Add if the map does not already have it
return !seenNames.has(name);
}
// First, look at the methods on the object itself, so this can properly
// proxy any methods not on the prototype (for example, in the mock player).
for (const key in player) {
if (shouldAddToTheMap(key)) {
seenNames.add(key);
operation(key, player[key]);
}
}
// The exact length of the prototype chain might vary; for resiliency, this
// will just look at the entire chain, rather than assuming a set length.
let proto = /** @type {!Object} */ (Object.getPrototypeOf(player));
const objProto = /** @type {!Object} */ (Object.getPrototypeOf({}));
while (proto && proto != objProto) { // Don't proxy Object methods.
for (const name of Object.getOwnPropertyNames(proto)) {
if (shouldAddToTheMap(name)) {
seenNames.add(name);
operation(name, (player)[name]);
}
}
proto = /** @type {!Object} */ (Object.getPrototypeOf(proto));
}
}
/**
* @return {shaka.cast.CastUtils.InitStateType} initState Video and player
* state to be sent to the receiver.
* @private
*/
getInitState_() {
const initState = {
'video': {},
'player': {},
'playerAfterLoad': {},
'manifest': this.localPlayer_.getAssetUri(),
'startTime': null,
};
// Pause local playback before capturing state.
this.localVideo_.pause();
for (const name of shaka.cast.CastUtils.VideoInitStateAttributes) {
initState['video'][name] = this.localVideo_[name];
}
// If the video is still playing, set the startTime.
// Has no effect if nothing is loaded.
if (!this.localVideo_.ended) {
initState['startTime'] = this.localVideo_.currentTime;
}
for (const pair of shaka.cast.CastUtils.PlayerInitState) {
const getter = pair[0];
const setter = pair[1];
const value = /** @type {Object} */(this.localPlayer_)[getter]();
initState['player'][setter] = value;
}
for (const pair of shaka.cast.CastUtils.PlayerInitAfterLoadState) {
const getter = pair[0];
const setter = pair[1];
const value = /** @type {Object} */(this.localPlayer_)[getter]();
initState['playerAfterLoad'][setter] = value;
}
return initState;
}
/**
* Dispatch an event to notify the app that the status has changed.
* @private
*/
onCastStatusChanged_() {
const event = new shaka.util.FakeEvent('caststatuschanged');
this.dispatchEvent(event);
}
/**
* Dispatch a synthetic play or pause event to ensure that the app correctly
* knows that the player is playing, if joining an existing receiver.
* @private
*/
onFirstCastStateUpdate_() {
const type = this.videoProxy_['paused'] ? 'pause' : 'play';
const fakeEvent = new shaka.util.FakeEvent(type);
this.videoEventTarget_.dispatchEvent(fakeEvent);
}
/**
* Transfer remote state back and resume local playback.
* @private
*/
onResumeLocal_() {
// Transfer back the player state.
for (const pair of shaka.cast.CastUtils.PlayerInitState) {
const getter = pair[0];
const setter = pair[1];
const value = this.sender_.get('player', getter)();
/** @type {Object} */(this.localPlayer_)[setter](value);
}
// Get the most recent manifest URI and ended state.
const assetUri = this.sender_.get('player', 'getAssetUri')();
const ended = this.sender_.get('video', 'ended');
let manifestReady = Promise.resolve();
const autoplay = this.localVideo_.autoplay;
let startTime = null;
// If the video is still playing, set the startTime.
// Has no effect if nothing is loaded.
if (!ended) {
startTime = this.sender_.get('video', 'currentTime');
}
// Now load the manifest, if present.
if (assetUri) {
// Don't autoplay the content until we finish setting up initial state.
this.localVideo_.autoplay = false;
manifestReady = this.localPlayer_.load(assetUri, startTime);
}
// Get the video state into a temp variable since we will apply it async.
const videoState = {};
for (const name of shaka.cast.CastUtils.VideoInitStateAttributes) {
videoState[name] = this.sender_.get('video', name);
}
// Finally, take on video state and player's "after load" state.
manifestReady.then(() => {
if (!this.localVideo_) {
// We've already been destroyed.
return;
}
for (const name of shaka.cast.CastUtils.VideoInitStateAttributes) {
this.localVideo_[name] = videoState[name];
}
for (const pair of shaka.cast.CastUtils.PlayerInitAfterLoadState) {
const getter = pair[0];
const setter = pair[1];
const value = this.sender_.get('player', getter)();
/** @type {Object} */(this.localPlayer_)[setter](value);
}
// Restore the original autoplay setting.
this.localVideo_.autoplay = autoplay;
if (assetUri) {
// Resume playback with transferred state.
this.localVideo_.play();
}
}, (error) => {
// Pass any errors through to the app.
goog.asserts.assert(error instanceof shaka.util.Error,
'Wrong error type!');
const eventType = shaka.Player.EventName.Error;
const data = (new Map()).set('detail', error);
const event = new shaka.util.FakeEvent(eventType, data);
this.localPlayer_.dispatchEvent(event);
});
}
/**
* @param {string} name
* @return {?}
* @private
*/
videoProxyGet_(name) {
if (name == 'addEventListener') {
return (type, listener, options) => {
return this.videoEventTarget_.addEventListener(type, listener, options);
};
}
if (name == 'removeEventListener') {
return (type, listener, options) => {
return this.videoEventTarget_.removeEventListener(
type, listener, options);
};
}
// If we are casting, but the first update has not come in yet, use local
// values, but not local methods.
if (this.sender_.isCasting() && !this.sender_.hasRemoteProperties()) {
const value = this.localVideo_[name];
if (typeof value != 'function') {
return value;
}
}
// Use local values and methods if we are not casting.
if (!this.sender_.isCasting()) {
let value = this.localVideo_[name];
if (typeof value == 'function') {
// eslint-disable-next-line no-restricted-syntax
value = value.bind(this.localVideo_);
}
return value;
}
return this.sender_.get('video', name);
}
/**
* @param {string} name
* @param {?} value
* @private
*/
videoProxySet_(name, value) {
if (!this.sender_.isCasting()) {
this.localVideo_[name] = value;
return;
}
this.sender_.set('video', name, value);
}
/**
* @param {!Event} event
* @private
*/
videoProxyLocalEvent_(event) {
if (this.sender_.isCasting()) {
// Ignore any unexpected local events while casting. Events can still be
// fired by the local video and Player when we unload() after the Cast
// connection is complete.
return;
}
// Convert this real Event into a FakeEvent for dispatch from our
// FakeEventListener.
const fakeEvent = shaka.util.FakeEvent.fromRealEvent(event);
this.videoEventTarget_.dispatchEvent(fakeEvent);
}
/**
* @param {string} name
* @return {?}
* @private
*/
playerProxyGet_(name) {
// If name is a shortened compiled name, get the original version
// from our map.
if (this.compiledToExternNames_.has(name)) {
name = this.compiledToExternNames_.get(name);
}
if (name == 'addEventListener') {
return (type, listener, options) => {
return this.playerEventTarget_.addEventListener(
type, listener, options);
};
}
if (name == 'removeEventListener') {
return (type, listener, options) => {
return this.playerEventTarget_.removeEventListener(
type, listener, options);
};
}
if (name == 'getMediaElement') {
return () => this.videoProxy_;
}
if (name == 'getSharedConfiguration') {
shaka.log.warning(
'Can\'t share configuration across a network. Returning copy.');
return this.sender_.get('player', 'getConfiguration');
}
if (name == 'getNetworkingEngine') {
// Always returns a local instance, in case you need to make a request.
// Issues a warning, in case you think you are making a remote request
// or affecting remote filters.
if (this.sender_.isCasting()) {
shaka.log.warning('NOTE: getNetworkingEngine() is always local!');
}
return () => this.localPlayer_.getNetworkingEngine();
}
if (name == 'getDrmEngine') {
// Always returns a local instance.
if (this.sender_.isCasting()) {
shaka.log.warning('NOTE: getDrmEngine() is always local!');
}
return () => this.localPlayer_.getDrmEngine();
}
if (name == 'getAdManager') {
// Always returns a local instance.
if (this.sender_.isCasting()) {
shaka.log.warning('NOTE: getAdManager() is always local!');
}
return () => this.localPlayer_.getAdManager();
}
if (name == 'setVideoContainer') {
// Always returns a local instance.
if (this.sender_.isCasting()) {
shaka.log.warning('NOTE: setVideoContainer() is always local!');
}
return (container) => this.localPlayer_.setVideoContainer(container);
}
if (this.sender_.isCasting()) {
// These methods are unavailable or otherwise stubbed during casting.
if (name == 'getManifest' || name == 'drmInfo') {
return () => {
shaka.log.alwaysWarn(name + '() does not work while casting!');
return null;
};
}
if (name == 'attach' || name == 'detach') {
return () => {
shaka.log.alwaysWarn(name + '() does not work while casting!');
return Promise.resolve();
};
}
} // if (this.sender_.isCasting())
// If we are casting, but the first update has not come in yet, use local
// getters, but not local methods.
if (this.sender_.isCasting() && !this.sender_.hasRemoteProperties()) {
if (shaka.cast.CastUtils.PlayerGetterMethods[name]) {
const value = /** @type {Object} */(this.localPlayer_)[name];
goog.asserts.assert(typeof value == 'function',
'only methods on Player');
// eslint-disable-next-line no-restricted-syntax
return value.bind(this.localPlayer_);
}
}
// Use local getters and methods if we are not casting.
if (!this.sender_.isCasting()) {
const value = /** @type {Object} */(this.localPlayer_)[name];
goog.asserts.assert(typeof value == 'function',
'only methods on Player');
// eslint-disable-next-line no-restricted-syntax
return value.bind(this.localPlayer_);
}
return this.sender_.get('player', name);
}
/**
* @param {!Event} event
* @private
*/
playerProxyLocalEvent_(event) {
if (this.sender_.isCasting()) {
// Ignore any unexpected local events while casting.
return;
}
this.playerEventTarget_.dispatchEvent(event);
}
/**
* @param {string} targetName
* @param {!shaka.util.FakeEvent} event
* @private
*/
onRemoteEvent_(targetName, event) {
goog.asserts.assert(this.sender_.isCasting(),
'Should only receive remote events while casting');
if (!this.sender_.isCasting()) {
// Ignore any unexpected remote events.
return;
}
if (targetName == 'video') {
this.videoEventTarget_.dispatchEvent(event);
} else if (targetName == 'player') {
this.playerEventTarget_.dispatchEvent(event);
}
}
};