add very early datachannel support

src/matrix/calls/LocalMedia.ts

@@ -22,7 +22,8 @@ export class LocalMedia {
     constructor(
         public readonly cameraTrack?: Track,
         public readonly screenShareTrack?: Track,
-        public readonly microphoneTrack?: AudioTrack
+        public readonly microphoneTrack?: AudioTrack,
+        public readonly dataChannelOptions?: RTCDataChannelInit,
     ) {}
 
     withTracks(tracks: Track[]) {
@@ -32,7 +33,11 @@ export class LocalMedia {
         if (cameraTrack && microphoneTrack && cameraTrack.streamId !== microphoneTrack.streamId) {
             throw new Error("The camera and audio track should have the same stream id");
         }
-        return new LocalMedia(cameraTrack, screenShareTrack, microphoneTrack as AudioTrack);
+        return new LocalMedia(cameraTrack, screenShareTrack, microphoneTrack as AudioTrack, this.dataChannelOptions);
+    }
+
+    withDataChannel(options: RTCDataChannelInit): LocalMedia {
+        return new LocalMedia(this.cameraTrack, this.screenShareTrack, this.microphoneTrack as AudioTrack, options);
     }
 
     get tracks(): Track[] {

src/matrix/calls/PeerCall.ts

@@ -85,6 +85,8 @@ export class PeerCall implements IDisposable {
     private sentEndOfCandidates: boolean = false;
     private iceDisconnectedTimeout?: Timeout;
 
+    private _dataChannel?: any;
+
     constructor(
         private callId: string,
         private readonly options: Options,
@@ -112,7 +114,12 @@ export class PeerCall implements IDisposable {
                     outer.options.emitUpdate(outer, undefined);
                 });
             },
-            onDataChannelChanged(dataChannel: DataChannel | undefined) {},
+            onRemoteDataChannel(dataChannel: any | undefined) {
+                outer.logItem.wrap("onRemoteDataChannel", log => {
+                    outer._dataChannel = dataChannel;
+                    outer.options.emitUpdate(outer, undefined);
+                });
+            },
             onNegotiationNeeded() {
                 const promiseCreator = () => {
                     return outer.logItem.wrap("onNegotiationNeeded", log => {
@@ -127,6 +134,8 @@ export class PeerCall implements IDisposable {
         });
     }
 
+    get dataChannel(): any | undefined { return this._dataChannel; }
+
     get state(): CallState { return this._state; }
 
     get remoteTracks(): Track[] {
@@ -144,6 +153,9 @@ export class PeerCall implements IDisposable {
             for (const t of this.localMedia.tracks) {
                 this.peerConnection.addTrack(t);
             }
+            if (this.localMedia.dataChannelOptions) {
+                this._dataChannel = this.peerConnection.createDataChannel(this.localMedia.dataChannelOptions);
+            }
             // after adding the local tracks, and wait for handleNegotiation to be called,
             // or invite glare where we give up our invite and answer instead
             await this.waitForState([CallState.InviteSent, CallState.CreateAnswer]);
@@ -160,7 +172,9 @@ export class PeerCall implements IDisposable {
             for (const t of this.localMedia.tracks) {
                 this.peerConnection.addTrack(t);
             }
-
+            if (this.localMedia.dataChannelOptions) {
+                this._dataChannel = this.peerConnection.createDataChannel(this.localMedia.dataChannelOptions);
+            }
             let myAnswer: RTCSessionDescriptionInit;
             try {
                 myAnswer = await this.peerConnection.createAnswer();

src/matrix/calls/group/Member.ts

@@ -66,6 +66,10 @@ export class Member {
         return this.callDeviceMembership.device_id;
     }
 
+    get dataChannel(): any | undefined {
+        return this.peerCall?.dataChannel;
+    }
+
     /** @internal */
     connect(localMedia: LocalMedia) {
         this.logItem.wrap("connect", () => {

src/platform/types/WebRTC.ts

@@ -26,21 +26,15 @@ export interface PeerConnectionHandler {
     onLocalIceCandidate(candidate: RTCIceCandidate);
     onIceGatheringStateChange(state: RTCIceGatheringState);
     onRemoteTracksChanged(tracks: Track[]);
-    onDataChannelChanged(dataChannel: DataChannel | undefined);
+    onRemoteDataChannel(dataChannel: any | undefined);
     onNegotiationNeeded();
     // request the type of incoming stream
     getPurposeForStreamId(streamId: string): SDPStreamMetadataPurpose;
 }
-// does it make sense to wrap this?
-export interface DataChannel {
-    close();
-    send();
-}
 
 export interface PeerConnection {
     notifyStreamPurposeChanged(): void;
     get remoteTracks(): Track[];
-    get dataChannel(): DataChannel | undefined;
     get iceGatheringState(): RTCIceGatheringState;
     get signalingState(): RTCSignalingState;
     get localDescription(): RTCSessionDescription | undefined;
@@ -52,7 +46,7 @@ export interface PeerConnection {
     addTrack(track: Track): void;
     removeTrack(track: Track): boolean;
     replaceTrack(oldTrack: Track, newTrack: Track): Promise<boolean>;
-    createDataChannel(): DataChannel;
+    createDataChannel(options: RTCDataChannelInit): any;
     dispose(): void;
     close(): void;
 }

src/platform/web/dom/WebRTC.ts

@@ -46,7 +46,6 @@ class DOMPeerConnection implements PeerConnection {
     }
 
     get remoteTracks(): Track[] { return this._remoteTracks; }
-    get dataChannel(): DataChannel | undefined { return undefined; }
     get iceGatheringState(): RTCIceGatheringState { return this.peerConnection.iceGatheringState; }
     get localDescription(): RTCSessionDescription | undefined { return this.peerConnection.localDescription ?? undefined; }
     get signalingState(): RTCSignalingState { return this.peerConnection.signalingState; }
@@ -119,8 +118,8 @@ class DOMPeerConnection implements PeerConnection {
         }
     }
 
-    createDataChannel(): DataChannel {
-        return undefined as any;// new DataChannel(this.peerConnection.createDataChannel());
+    createDataChannel(options: RTCDataChannelInit): any {
+        return this.peerConnection.createDataChannel("channel", options);
     }
 
     private registerHandler() {
@@ -164,6 +163,7 @@ class DOMPeerConnection implements PeerConnection {
                 this.handler.onNegotiationNeeded();
                 break;
             case "datachannel":
+                this.handler.onRemoteDataChannel((evt as RTCDataChannelEvent).channel);
                 break;
         }
     }