implemented tracks, local & remote participants

2021-07-21 23:30:24 -07:00
parent 0a682f7831
commit b18c37fd1a
14 changed files with 468 additions and 16 deletions
@@ -1,3 +1,136 @@
+import 'package:flutter_webrtc/flutter_webrtc.dart';
+import '../proto/livekit_models.pb.dart';
+import '../signal_client.dart';
+import '../track/remote_track_publication.dart';
+import '../track/track.dart';
+import '../track/video_track.dart';
 import 'participant.dart';

-class RemoteParticipant extends Participant {}
+class RemoteParticipant extends Participant {
+  SignalClient _client;
+
+  SignalClient get client => _client;
+
+  RemoteParticipant(this._client, String sid, String identity)
+      : super(sid, identity);
+
+  RemoteParticipant.fromInfo(this._client, ParticipantInfo info)
+      : super(info.sid, info.identity) {
+    updateFromInfo(info);
+  }
+
+  RemoteTrackPublication? getTrackPublication(String sid) {
+    var pub = tracks[sid];
+    if (pub is RemoteTrackPublication) {
+      return pub;
+    }
+  }
+
+  addSubscribedMediaTrack(MediaStreamTrack mediaTrack, String sid) async {
+    var pub = getTrackPublication(sid);
+    if (pub == null) {
+      // we may have received the track prior to metadata. wait up to 3s
+      pub = await _waitForTrackPublication(sid, Duration(seconds: 3));
+      if (pub == null) {
+        var msg = 'no track metadata found';
+        delegate?.onTrackSubscriptionFailed(this, sid, msg);
+        roomDelegate?.onTrackSubscriptionFailed(this, sid, msg);
+        return;
+      }
+    }
+
+    Track? track;
+    if (pub.kind == TrackType.AUDIO) {
+      track = new Track(pub.kind, pub.name, mediaTrack);
+    } else if (pub.kind == TrackType.VIDEO) {
+      track = new VideoTrack(pub.name, mediaTrack);
+    } else {
+      var msg = 'unsupported track type ${pub.kind}';
+      delegate?.onTrackSubscriptionFailed(this, sid, msg);
+      roomDelegate?.onTrackSubscriptionFailed(this, sid, msg);
+      return;
+    }
+
+    pub.track = track;
+    addTrackPublication(pub);
+
+    delegate?.onTrackSubscribed(this, track, pub);
+    roomDelegate?.onTrackSubscribed(this, track, pub);
+  }
+
+  @override
+  void updateFromInfo(ParticipantInfo info) {
+    var hadInfo = hasInfo;
+    super.updateFromInfo(info);
+
+    // figuring out deltas between tracks
+    var validPubs = Map<String, RemoteTrackPublication>();
+    var newPubs = Map<String, RemoteTrackPublication>();
+
+    for (var info in info.tracks) {
+      var sid = info.sid;
+      var pub = getTrackPublication(sid);
+
+      if (pub == null) {
+        pub = RemoteTrackPublication(info, this);
+        newPubs[sid] = pub;
+        addTrackPublication(pub);
+      } else {
+        pub.updateFromInfo(info);
+      }
+
+      validPubs[sid] = pub;
+    }
+
+    // notify listeners when it's not a new participant
+    if (hadInfo) {
+      for (var pub in newPubs.values) {
+        delegate?.onTrackPublished(this, pub);
+        roomDelegate?.onTrackPublished(this, pub);
+      }
+      return;
+    }
+
+    // remove tracks
+    for (var pub in tracks.values) {
+      if (!validPubs.containsKey(pub.sid)) {
+        unpublishTrack(sid, true);
+      }
+    }
+  }
+
+  unpublishTrack(String sid, [bool sendUnpublish = false]) {
+    var pub = tracks.remove(sid);
+    if (pub == null || !(pub is RemoteTrackPublication)) {
+      return;
+    }
+
+    audioTracks.remove(sid);
+    videoTracks.remove(sid);
+
+    var track = pub.track;
+    if (track != null) {
+      track.stop();
+      delegate?.onTrackUnsubscribed(this, track, pub);
+      roomDelegate?.onTrackUnsubscribed(this, track, pub);
+    }
+    if (sendUnpublish) {
+      delegate?.onTrackUnpublished(this, pub);
+      roomDelegate?.onTrackUnpublished(this, pub);
+    }
+  }
+
+  Future<RemoteTrackPublication?> _waitForTrackPublication(
+      String sid, Duration delay) async {
+    var endTime = DateTime.now().add(delay);
+    while (DateTime.now().isBefore(endTime)) {
+      var pub = await Future<RemoteTrackPublication?>.delayed(
+          Duration(milliseconds: 100), () {
+        return getTrackPublication(sid);
+      });
+      if (pub != null) {
+        return pub;
+      }
+    }
+  }
+}