ref(JitsiConference): move sendTones impl to TPC (#983)

Moves sendTones implementation to TraceablePeerConnection. It will be
responsible for creating/storing a DTMFSender. JitsiConference will
use the currently active TraceablePeerConnection to send the tones.

This fixes a bug where DTMF tones can not be sent after
JingleSessionPC/TraceablePeerConnection instance changes.
The JitsiDTMFManager instance was referencing invalid PeerConnection.

JitsiConference.js

 import * as JitsiTrackErrors from './JitsiTrackErrors';
 import * as JitsiTrackEvents from './JitsiTrackEvents';
 import authenticateAndUpgradeRole from './authenticateAndUpgradeRole';
-import JitsiDTMFManager from './modules/DTMF/JitsiDTMFManager';
 import P2PDominantSpeakerDetection from './modules/P2PDominantSpeakerDetection';
 import RTC from './modules/RTC/RTC';
 import TalkMutedDetection from './modules/TalkMutedDetection';
 };
 
 JitsiConference.prototype.sendTones = function(tones, duration, pause) {
-    if (!this.dtmfManager) {
-        const peerConnection = this.getActivePeerConnection();
-
-        if (!peerConnection) {
-            logger.warn('cannot sendTones: no peer connection');
-
-            return;
-        }
-
-        const localAudio = this.getLocalAudioTrack();
-
-        if (!localAudio) {
-            logger.warn('cannot sendTones: no local audio stream');
+    const peerConnection = this.getActivePeerConnection();
 
-            return;
-        }
-        this.dtmfManager = new JitsiDTMFManager(localAudio, peerConnection);
+    if (peerConnection) {
+        peerConnection.sendTones(tones, duration, pause);
+    } else {
+        logger.warn('cannot sendTones: no peer connection');
     }
-
-    this.dtmfManager.sendTones(tones, duration, pause);
 };
 
 /**

modules/DTMF/JitsiDTMFManager.js

-const logger = require('jitsi-meet-logger').getLogger(__filename);
-
-/**
- *
- * @param localAudio
- * @param peerConnection
- */
-function JitsiDTMFManager(localAudio, peerConnection) {
-    const audioTrack = localAudio.getTrack();
-
-    if (!audioTrack) {
-        throw new Error('Failed to initialize DTMFSender: no audio track.');
-    }
-    this.dtmfSender
-        = peerConnection.peerconnection.createDTMFSender(audioTrack);
-    logger.debug('Initialized DTMFSender');
-}
-
-JitsiDTMFManager.prototype.sendTones = function(tones, duration, pause) {
-    this.dtmfSender.insertDTMF(tones, duration || 200, pause || 200);
-};
-
-module.exports = JitsiDTMFManager;
-

modules/RTC/TraceablePeerConnection.js

      */
     this.audioTransferActive = !(options.startSilent === true);
 
+    /**
+     * The DTMF sender instance used to send DTMF tones.
+     *
+     * @type {RTCDTMFSender|undefined}
+     * @private
+     */
+    this._dtmfSender = undefined;
+
     /**
      * Indicates whether or not this peer connection instance is actively
      * sending/receiving video media. When set to <tt>false</tt> the SDP video
     return changed;
 };
 
+/**
+ * Sends DTMF tones if possible.
+ *
+ * @param {string} tones - The DTMF tones string as defined by {@code RTCDTMFSender.insertDTMF}, 'tones' argument.
+ * @param {number} duration - The amount of time in milliseconds that each DTMF should last. It's 200ms by default.
+ * @param {number} interToneGap - The length of time in miliseconds to wait between tones. It's 200ms by default.
+ *
+ * @returns {void}
+ */
+TraceablePeerConnection.prototype.sendTones = function(tones, duration = 200, interToneGap = 200) {
+    if (!this._dtmfSender) {
+        if (this.peerconnection.getSenders) {
+            const rtpSender = this.peerconnection.getSenders().find(s => s.dtmf);
+
+            this._dtmfSender = rtpSender && rtpSender.dtmf;
+            this._dtmfSender && logger.info(`${this} initialized DTMFSender using getSenders`);
+        }
+
+        if (!this._dtmfSender) {
+            const localAudioTrack = Array.from(this.localTracks.values()).find(t => t.isAudioTrack());
+
+            if (this.peerconnection.createDTMFSender && localAudioTrack) {
+                this._dtmfSender = this.peerconnection.createDTMFSender(localAudioTrack.getTrack());
+            }
+            this._dtmfSender && logger.info(`${this} initialized DTMFSender using deprecated createDTMFSender`);
+        }
+    }
+
+    if (this._dtmfSender) {
+        this._dtmfSender.insertDTMF(tones, duration, interToneGap);
+    } else {
+        logger.warn(`${this} sendTones - failed to select DTMFSender`);
+    }
+};
+
 /**
  * Makes the underlying TraceablePeerConnection generate new SSRC for
  * the recvonly video stream.