webrtc-adapter
Version:
A shim to insulate apps from WebRTC spec changes and browser prefix differences
578 lines (534 loc) • 21.3 kB
JavaScript
/*
* Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree.
*/
/* eslint-env node */
;
var utils = require('../utils.js');
var logging = utils.log;
var chromeShim = {
shimMediaStream: function(window) {
window.MediaStream = window.MediaStream || window.webkitMediaStream;
},
shimOnTrack: function(window) {
if (typeof window === 'object' && window.RTCPeerConnection && !('ontrack' in
window.RTCPeerConnection.prototype)) {
Object.defineProperty(window.RTCPeerConnection.prototype, 'ontrack', {
get: function() {
return this._ontrack;
},
set: function(f) {
if (this._ontrack) {
this.removeEventListener('track', this._ontrack);
}
this.addEventListener('track', this._ontrack = f);
}
});
var origSetRemoteDescription =
window.RTCPeerConnection.prototype.setRemoteDescription;
window.RTCPeerConnection.prototype.setRemoteDescription = function() {
var pc = this;
if (!pc._ontrackpoly) {
pc._ontrackpoly = function(e) {
// onaddstream does not fire when a track is added to an existing
// stream. But stream.onaddtrack is implemented so we use that.
e.stream.addEventListener('addtrack', function(te) {
var receiver;
if (window.RTCPeerConnection.prototype.getReceivers) {
receiver = pc.getReceivers().find(function(r) {
return r.track.id === te.track.id;
});
} else {
receiver = {track: te.track};
}
var event = new Event('track');
event.track = te.track;
event.receiver = receiver;
event.streams = [e.stream];
pc.dispatchEvent(event);
});
e.stream.getTracks().forEach(function(track) {
var receiver;
if (window.RTCPeerConnection.prototype.getReceivers) {
receiver = pc.getReceivers().find(function(r) {
return r.track.id === track.id;
});
} else {
receiver = {track: track};
}
var event = new Event('track');
event.track = track;
event.receiver = receiver;
event.streams = [e.stream];
pc.dispatchEvent(event);
});
};
pc.addEventListener('addstream', pc._ontrackpoly);
}
return origSetRemoteDescription.apply(pc, arguments);
};
}
},
shimGetSendersWithDtmf: function(window) {
// Overrides addTrack/removeTrack, depends on shimAddTrackRemoveTrack.
if (typeof window === 'object' && window.RTCPeerConnection &&
!('getSenders' in window.RTCPeerConnection.prototype) &&
'createDTMFSender' in window.RTCPeerConnection.prototype) {
var shimSenderWithDtmf = function(pc, track) {
return {
track: track,
get dtmf() {
if (this._dtmf === undefined) {
if (track.kind === 'audio') {
this._dtmf = pc.createDTMFSender(track);
} else {
this._dtmf = null;
}
}
return this._dtmf;
},
_pc: pc
};
};
// augment addTrack when getSenders is not available.
if (!window.RTCPeerConnection.prototype.getSenders) {
window.RTCPeerConnection.prototype.getSenders = function() {
this._senders = this._senders || [];
return this._senders.slice(); // return a copy of the internal state.
};
var origAddTrack = window.RTCPeerConnection.prototype.addTrack;
window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
var pc = this;
var sender = origAddTrack.apply(pc, arguments);
if (!sender) {
sender = shimSenderWithDtmf(pc, track);
pc._senders.push(sender);
}
return sender;
};
var origRemoveTrack = window.RTCPeerConnection.prototype.removeTrack;
window.RTCPeerConnection.prototype.removeTrack = function(sender) {
var pc = this;
origRemoveTrack.apply(pc, arguments);
var idx = pc._senders.indexOf(sender);
if (idx !== -1) {
pc._senders.splice(idx, 1);
}
};
}
var origAddStream = window.RTCPeerConnection.prototype.addStream;
window.RTCPeerConnection.prototype.addStream = function(stream) {
var pc = this;
pc._senders = pc._senders || [];
origAddStream.apply(pc, [stream]);
stream.getTracks().forEach(function(track) {
pc._senders.push(shimSenderWithDtmf(pc, track));
});
};
var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
window.RTCPeerConnection.prototype.removeStream = function(stream) {
var pc = this;
pc._senders = pc._senders || [];
origRemoveStream.apply(pc, [(pc._streams[stream.id] || stream)]);
stream.getTracks().forEach(function(track) {
var sender = pc._senders.find(function(s) {
return s.track === track;
});
if (sender) {
pc._senders.splice(pc._senders.indexOf(sender), 1); // remove sender
}
});
};
} else if (typeof window === 'object' && window.RTCPeerConnection &&
'getSenders' in window.RTCPeerConnection.prototype &&
'createDTMFSender' in window.RTCPeerConnection.prototype &&
window.RTCRtpSender &&
!('dtmf' in window.RTCRtpSender.prototype)) {
var origGetSenders = window.RTCPeerConnection.prototype.getSenders;
window.RTCPeerConnection.prototype.getSenders = function() {
var pc = this;
var senders = origGetSenders.apply(pc, []);
senders.forEach(function(sender) {
sender._pc = pc;
});
return senders;
};
Object.defineProperty(window.RTCRtpSender.prototype, 'dtmf', {
get: function() {
if (this._dtmf === undefined) {
if (this.track.kind === 'audio') {
this._dtmf = this._pc.createDTMFSender(this.track);
} else {
this._dtmf = null;
}
}
return this._dtmf;
}
});
}
},
shimSourceObject: function(window) {
var URL = window && window.URL;
if (typeof window === 'object') {
if (window.HTMLMediaElement &&
!('srcObject' in window.HTMLMediaElement.prototype)) {
// Shim the srcObject property, once, when HTMLMediaElement is found.
Object.defineProperty(window.HTMLMediaElement.prototype, 'srcObject', {
get: function() {
return this._srcObject;
},
set: function(stream) {
var self = this;
// Use _srcObject as a private property for this shim
this._srcObject = stream;
if (this.src) {
URL.revokeObjectURL(this.src);
}
if (!stream) {
this.src = '';
return undefined;
}
this.src = URL.createObjectURL(stream);
// We need to recreate the blob url when a track is added or
// removed. Doing it manually since we want to avoid a recursion.
stream.addEventListener('addtrack', function() {
if (self.src) {
URL.revokeObjectURL(self.src);
}
self.src = URL.createObjectURL(stream);
});
stream.addEventListener('removetrack', function() {
if (self.src) {
URL.revokeObjectURL(self.src);
}
self.src = URL.createObjectURL(stream);
});
}
});
}
}
},
shimAddTrackRemoveTrack: function(window) {
// shim addTrack and removeTrack.
if (window.RTCPeerConnection.prototype.addTrack) {
return;
}
// also shim pc.getLocalStreams when addTrack is shimmed
// to return the original streams.
var origGetLocalStreams = window.RTCPeerConnection.prototype
.getLocalStreams;
window.RTCPeerConnection.prototype.getLocalStreams = function() {
var self = this;
var nativeStreams = origGetLocalStreams.apply(this);
self._reverseStreams = self._reverseStreams || {};
return nativeStreams.map(function(stream) {
return self._reverseStreams[stream.id];
});
};
var origAddStream = window.RTCPeerConnection.prototype.addStream;
window.RTCPeerConnection.prototype.addStream = function(stream) {
var pc = this;
pc._streams = pc._streams || {};
pc._reverseStreams = pc._reverseStreams || {};
stream.getTracks().forEach(function(track) {
var alreadyExists = pc.getSenders().find(function(s) {
return s.track === track;
});
if (alreadyExists) {
throw new DOMException('Track already exists.',
'InvalidAccessError');
}
});
// Add identity mapping for consistency with addTrack.
// Unless this is being used with a stream from addTrack.
if (!pc._reverseStreams[stream.id]) {
var newStream = new window.MediaStream(stream.getTracks());
pc._streams[stream.id] = newStream;
pc._reverseStreams[newStream.id] = stream;
stream = newStream;
}
origAddStream.apply(pc, [stream]);
};
var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
window.RTCPeerConnection.prototype.removeStream = function(stream) {
var pc = this;
pc._streams = pc._streams || {};
pc._reverseStreams = pc._reverseStreams || {};
origRemoveStream.apply(pc, [(pc._streams[stream.id] || stream)]);
delete pc._reverseStreams[(pc._streams[stream.id] ?
pc._streams[stream.id].id : stream.id)];
delete pc._streams[stream.id];
};
window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
var pc = this;
if (pc.signalingState === 'closed') {
throw new DOMException(
'The RTCPeerConnection\'s signalingState is \'closed\'.',
'InvalidStateError');
}
var streams = [].slice.call(arguments, 1);
if (streams.length !== 1 ||
!streams[0].getTracks().find(function(t) {
return t === track;
})) {
// this is not fully correct but all we can manage without
// [[associated MediaStreams]] internal slot.
throw new DOMException(
'The adapter.js addTrack polyfill only supports a single ' +
' stream which is associated with the specified track.',
'NotSupportedError');
}
var alreadyExists = pc.getSenders().find(function(s) {
return s.track === track;
});
if (alreadyExists) {
throw new DOMException('Track already exists.',
'InvalidAccessError');
}
pc._streams = pc._streams || {};
pc._reverseStreams = pc._reverseStreams || {};
var oldStream = pc._streams[stream.id];
if (oldStream) {
// this is using odd Chrome behaviour, use with caution:
// https://bugs.chromium.org/p/webrtc/issues/detail?id=7815
// Note: we rely on the high-level addTrack/dtmf shim to
// create the sender with a dtmf sender.
oldStream.addTrack(track);
pc.dispatchEvent(new Event('negotiationneeded'));
} else {
var newStream = new window.MediaStream([track]);
pc._streams[stream.id] = newStream;
pc._reverseStreams[newStream.id] = stream;
pc.addStream(newStream);
}
return pc.getSenders().find(function(s) {
return s.track === track;
});
};
window.RTCPeerConnection.prototype.removeTrack = function(sender) {
var pc = this;
if (pc.signalingState === 'closed') {
throw new DOMException(
'The RTCPeerConnection\'s signalingState is \'closed\'.',
'InvalidStateError');
}
var isLocal = sender._pc === pc;
if (!isLocal) {
throw new DOMException('Sender was not created by this connection.',
'InvalidAccessError');
}
// Search for the native stream the senders track belongs to.
pc._streams = pc._streams || {};
var stream;
Object.keys(pc._streams).forEach(function(streamid) {
var hasTrack = pc._streams[streamid].getTracks().find(function(track) {
return sender.track === track;
});
if (hasTrack) {
stream = pc._streams[streamid];
}
});
if (stream) {
if (stream.getTracks().length === 1) {
// if this is the last track of the stream, remove the stream. This
// takes care of any shimmed _senders.
pc.removeStream(stream);
} else {
// relying on the same odd chrome behaviour as above.
stream.removeTrack(sender.track);
}
pc.dispatchEvent(new Event('negotiationneeded'));
}
};
},
shimPeerConnection: function(window) {
var browserDetails = utils.detectBrowser(window);
// The RTCPeerConnection object.
if (!window.RTCPeerConnection) {
window.RTCPeerConnection = function(pcConfig, pcConstraints) {
// Translate iceTransportPolicy to iceTransports,
// see https://code.google.com/p/webrtc/issues/detail?id=4869
// this was fixed in M56 along with unprefixing RTCPeerConnection.
logging('PeerConnection');
if (pcConfig && pcConfig.iceTransportPolicy) {
pcConfig.iceTransports = pcConfig.iceTransportPolicy;
}
return new window.webkitRTCPeerConnection(pcConfig, pcConstraints);
};
window.RTCPeerConnection.prototype =
window.webkitRTCPeerConnection.prototype;
// wrap static methods. Currently just generateCertificate.
if (window.webkitRTCPeerConnection.generateCertificate) {
Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
get: function() {
return window.webkitRTCPeerConnection.generateCertificate;
}
});
}
} else {
// migrate from non-spec RTCIceServer.url to RTCIceServer.urls
var OrigPeerConnection = window.RTCPeerConnection;
window.RTCPeerConnection = function(pcConfig, pcConstraints) {
if (pcConfig && pcConfig.iceServers) {
var newIceServers = [];
for (var i = 0; i < pcConfig.iceServers.length; i++) {
var server = pcConfig.iceServers[i];
if (!server.hasOwnProperty('urls') &&
server.hasOwnProperty('url')) {
console.warn('RTCIceServer.url is deprecated! Use urls instead.');
server = JSON.parse(JSON.stringify(server));
server.urls = server.url;
newIceServers.push(server);
} else {
newIceServers.push(pcConfig.iceServers[i]);
}
}
pcConfig.iceServers = newIceServers;
}
return new OrigPeerConnection(pcConfig, pcConstraints);
};
window.RTCPeerConnection.prototype = OrigPeerConnection.prototype;
// wrap static methods. Currently just generateCertificate.
Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
get: function() {
return OrigPeerConnection.generateCertificate;
}
});
}
var origGetStats = window.RTCPeerConnection.prototype.getStats;
window.RTCPeerConnection.prototype.getStats = function(selector,
successCallback, errorCallback) {
var self = this;
var args = arguments;
// If selector is a function then we are in the old style stats so just
// pass back the original getStats format to avoid breaking old users.
if (arguments.length > 0 && typeof selector === 'function') {
return origGetStats.apply(this, arguments);
}
// When spec-style getStats is supported, return those when called with
// either no arguments or the selector argument is null.
if (origGetStats.length === 0 && (arguments.length === 0 ||
typeof arguments[0] !== 'function')) {
return origGetStats.apply(this, []);
}
var fixChromeStats_ = function(response) {
var standardReport = {};
var reports = response.result();
reports.forEach(function(report) {
var standardStats = {
id: report.id,
timestamp: report.timestamp,
type: {
localcandidate: 'local-candidate',
remotecandidate: 'remote-candidate'
}[report.type] || report.type
};
report.names().forEach(function(name) {
standardStats[name] = report.stat(name);
});
standardReport[standardStats.id] = standardStats;
});
return standardReport;
};
// shim getStats with maplike support
var makeMapStats = function(stats) {
return new Map(Object.keys(stats).map(function(key) {
return [key, stats[key]];
}));
};
if (arguments.length >= 2) {
var successCallbackWrapper_ = function(response) {
args[1](makeMapStats(fixChromeStats_(response)));
};
return origGetStats.apply(this, [successCallbackWrapper_,
arguments[0]]);
}
// promise-support
return new Promise(function(resolve, reject) {
origGetStats.apply(self, [
function(response) {
resolve(makeMapStats(fixChromeStats_(response)));
}, reject]);
}).then(successCallback, errorCallback);
};
// add promise support -- natively available in Chrome 51
if (browserDetails.version < 51) {
['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
.forEach(function(method) {
var nativeMethod = window.RTCPeerConnection.prototype[method];
window.RTCPeerConnection.prototype[method] = function() {
var args = arguments;
var self = this;
var promise = new Promise(function(resolve, reject) {
nativeMethod.apply(self, [args[0], resolve, reject]);
});
if (args.length < 2) {
return promise;
}
return promise.then(function() {
args[1].apply(null, []);
},
function(err) {
if (args.length >= 3) {
args[2].apply(null, [err]);
}
});
};
});
}
// promise support for createOffer and createAnswer. Available (without
// bugs) since M52: crbug/619289
if (browserDetails.version < 52) {
['createOffer', 'createAnswer'].forEach(function(method) {
var nativeMethod = window.RTCPeerConnection.prototype[method];
window.RTCPeerConnection.prototype[method] = function() {
var self = this;
if (arguments.length < 1 || (arguments.length === 1 &&
typeof arguments[0] === 'object')) {
var opts = arguments.length === 1 ? arguments[0] : undefined;
return new Promise(function(resolve, reject) {
nativeMethod.apply(self, [resolve, reject, opts]);
});
}
return nativeMethod.apply(this, arguments);
};
});
}
// shim implicit creation of RTCSessionDescription/RTCIceCandidate
['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
.forEach(function(method) {
var nativeMethod = window.RTCPeerConnection.prototype[method];
window.RTCPeerConnection.prototype[method] = function() {
arguments[0] = new ((method === 'addIceCandidate') ?
window.RTCIceCandidate :
window.RTCSessionDescription)(arguments[0]);
return nativeMethod.apply(this, arguments);
};
});
// support for addIceCandidate(null or undefined)
var nativeAddIceCandidate =
window.RTCPeerConnection.prototype.addIceCandidate;
window.RTCPeerConnection.prototype.addIceCandidate = function() {
if (!arguments[0]) {
if (arguments[1]) {
arguments[1].apply(null);
}
return Promise.resolve();
}
return nativeAddIceCandidate.apply(this, arguments);
};
}
};
// Expose public methods.
module.exports = {
shimMediaStream: chromeShim.shimMediaStream,
shimOnTrack: chromeShim.shimOnTrack,
shimAddTrackRemoveTrack: chromeShim.shimAddTrackRemoveTrack,
shimGetSendersWithDtmf: chromeShim.shimGetSendersWithDtmf,
shimSourceObject: chromeShim.shimSourceObject,
shimPeerConnection: chromeShim.shimPeerConnection,
shimGetUserMedia: require('./getusermedia')
};