Add wrapper for MediaDevices

MediaDevicesManager stores the id of the audio and video input devices
to be used when requesting media. If no id is set then it behaves like
before, that is, letting the browser decide which device to use.

Signed-off-by: Daniel Calviño Sánchez <[email protected]>

src/utils/webrtc/MediaDevicesManager.js

@@ -0,0 +1,87 @@
+/**
+ *
+ * @copyright Copyright (c) 2020, Daniel Calviño Sánchez ([email protected])
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * Wrapper for MediaDevices to simplify its use.
+ *
+ * "attributes.audioInputId" and "attributes.videoInputId" define the devices
+ * that will be used when calling "getUserMedia(constraints)".
+ */
+export default function MediaDevicesManager() {
+	this.attributes = {
+		audioInputId: undefined,
+		videoInputId: undefined,
+	}
+}
+MediaDevicesManager.prototype = {
+
+	/**
+	 * Returns whether getting user media and enumerating media devices is
+	 * supported or not.
+	 *
+	 * Note that even if false is returned the MediaDevices interface could be
+	 * technically supported by the browser but not available due to the page
+	 * being loaded in an insecure context.
+	 *
+	 * @returns {boolean} true if MediaDevices interface is supported, false
+	 *          otherwise.
+	 */
+	isSupported: function() {
+		return navigator && navigator.mediaDevices && navigator.mediaDevices.getUserMedia && navigator.mediaDevices.enumerateDevices
+	},
+
+	/**
+	 * Wrapper for MediaDevices.getUserMedia to use the selected audio and video
+	 * input devices.
+	 *
+	 * The selected audio and video input devices are used only if the
+	 * constraints do not specify a device already. Otherwise the devices in the
+	 * constraints are respected.
+	 *
+	 * @param {MediaStreamConstraints} constraints the constraints specifying
+	 *        the media to request
+	 * @returns {Promise} resolved with a MediaStream object when successful, or
+	 *          rejected with a DOMException in case of error
+	 */
+	getUserMedia: function(constraints) {
+		if (!this.isSupported()) {
+			return new Promise((resolve, reject) => {
+				reject(new DOMException('MediaDevicesManager is not supported', 'NotSupportedError'))
+			})
+		}
+
+		if (constraints.audio && !constraints.audio.deviceId && this.attributes.audioInputId) {
+			if (!(constraints.audio instanceof Object)) {
+				constraints.audio = {}
+			}
+			constraints.audio.deviceId = this.attributes.audioInputId
+		}
+
+		if (constraints.video && !constraints.video.deviceId && this.attributes.videoInputId) {
+			if (!(constraints.video instanceof Object)) {
+				constraints.video = {}
+			}
+			constraints.video.deviceId = this.attributes.videoInputId
+		}
+
+		return navigator.mediaDevices.getUserMedia(constraints)
+	},
+}

src/utils/webrtc/index.js

@@ -27,6 +27,7 @@ import CallAnalyzer from './analyzers/CallAnalyzer'
 import CallParticipantCollection from './models/CallParticipantCollection'
 import LocalCallParticipantModel from './models/LocalCallParticipantModel'
 import LocalMediaModel from './models/LocalMediaModel'
+import MediaDevicesManager from './MediaDevicesManager'
 import SentVideoQualityThrottler from './SentVideoQualityThrottler'
 import { PARTICIPANT } from '../../constants'
 import { fetchSignalingSettings } from '../../services/signalingService'
@@ -35,6 +36,7 @@ let webRtc = null
 const callParticipantCollection = new CallParticipantCollection()
 const localCallParticipantModel = new LocalCallParticipantModel()
 const localMediaModel = new LocalMediaModel()
+const mediaDevicesManager = new MediaDevicesManager()
 let callAnalyzer = null
 let sentVideoQualityThrottler = null
 
@@ -225,6 +227,8 @@ export {
 	localCallParticipantModel,
 	localMediaModel,
 
+	mediaDevicesManager,
+
 	callAnalyzer,
 
 	signalingJoinConversation,

src/utils/webrtc/simplewebrtc/localmedia.js

@@ -5,6 +5,9 @@ const hark = require('hark')
 const getScreenMedia = require('./getscreenmedia')
 const WildEmitter = require('wildemitter')
 const mockconsole = require('mockconsole')
+// Only mediaDevicesManager is used, but it can not be assigned here due to not
+// being initialized yet.
+const webrtcIndex = require('../index.js')
 
 function isAllTracksEnded(stream) {
 	let isAllTracksEnded = true
@@ -43,7 +46,7 @@ function LocalMedia(opts) {
 	this._audioMonitorStreams = []
 	this.localScreens = []
 
-	if (!navigator.mediaDevices || !navigator.mediaDevices.getUserMedia) {
+	if (!webrtcIndex.mediaDevicesManager.isSupported()) {
 		this._logerror('Your browser does not support local media capture.')
 	}
 
@@ -86,7 +89,7 @@ LocalMedia.prototype.start = function(mediaConstraints, cb, context) {
 	const self = this
 	const constraints = mediaConstraints || this.config.media
 
-	if (!navigator || !navigator.mediaDevices || !navigator.mediaDevices.getUserMedia) {
+	if (!webrtcIndex.mediaDevicesManager.isSupported()) {
 		const error = new Error('MediaStreamError')
 		error.name = 'NotSupportedError'
 
@@ -99,7 +102,7 @@ LocalMedia.prototype.start = function(mediaConstraints, cb, context) {
 
 	this.emit('localStreamRequested', constraints, context)
 
-	navigator.mediaDevices.getUserMedia(constraints).then(function(stream) {
+	webrtcIndex.mediaDevicesManager.getUserMedia(constraints).then(function(stream) {
 		// Although the promise should be resolved only if all the constraints
 		// are met Edge resolves it if both audio and video are requested but
 		// only audio is available.