Subscription permission API (#68)

* signal

* request

* implement

* rename event

* ref

* adjustments based on review

* override subscribed

* move events emit

* fix subscription state

* minor change

* update example for permissions demo

* format & subscriptionState as computed property

* prepare macos build

* unsubscribed event when subscription not allowed

lib/src/core/engine.dart

@@ -621,6 +621,8 @@ class Engine extends Disposable with EventsEmittable<EngineEvent> {
     ..on<SignalStreamStateUpdatedEvent>((event) => events.emit(event))
     // relay to Room
     ..on<SignalSubscribedQualityUpdatedEvent>((event) => events.emit(event))
+    // relay to Room
+    ..on<SignalSubscriptionPermissionUpdateEvent>((event) => events.emit(event))
     ..on<SignalLeaveEvent>((event) async {
       if (connectionState == ConnectionState.reconnecting) {
         logger.warning('Received leave signal while engine is reconnecting.');

lib/src/core/room.dart

@@ -191,6 +191,25 @@ class Room extends DisposableChangeNotifier with EventsEmittable<RoomEvent> {
       }
       publication.updatePublishingLayers(event.updates);
     })
+    ..on<SignalSubscriptionPermissionUpdateEvent>((event) async {
+      logger.fine('SignalSubscriptionPermissionUpdateEvent '
+          'participantSid:${event.participantSid} '
+          'trackSid:${event.trackSid} '
+          'allowed:${event.allowed}');
+
+      // find participant
+      final participant = _participants[event.participantSid];
+      if (participant == null) {
+        return;
+      }
+      // find track
+      final publication = participant.trackPublications[event.trackSid];
+      if (publication == null) {
+        return;
+      }
+      //
+      await publication.updateSubscriptionAllowed(event.allowed);
+    })
     ..on<EngineTrackAddedEvent>((event) async {
       logger.fine('EngineTrackAddedEvent trackSid:${event.track.id}');
 

lib/src/core/signal_client.dart

@@ -186,6 +186,13 @@ class SignalClient extends Disposable with EventsEmittable<SignalEvent> {
           updates: msg.subscribedQualityUpdate.subscribedQualities,
         ));
         break;
+      case lk_rtc.SignalResponse_Message.subscriptionPermissionUpdate:
+        events.emit(SignalSubscriptionPermissionUpdateEvent(
+          participantSid: msg.subscriptionPermissionUpdate.participantSid,
+          trackSid: msg.subscriptionPermissionUpdate.trackSid,
+          allowed: msg.subscriptionPermissionUpdate.allowed,
+        ));
+        break;
       default:
         logger.warning('skipping unsupported signal message');
     }
@@ -296,6 +303,17 @@ extension SignalClientRequests on SignalClient {
         ),
       ));
 
+  void sendUpdateSubscriptionPermissions({
+    required bool allParticipants,
+    required List<lk_rtc.TrackPermission> trackPermissions,
+  }) =>
+      _sendRequest(lk_rtc.SignalRequest(
+        subscriptionPermissions: lk_rtc.UpdateSubscriptionPermissions(
+          allParticipants: allParticipants,
+          trackPermissions: trackPermissions,
+        ),
+      ));
+
   void sendLeave() => _sendRequest(lk_rtc.SignalRequest(
         leave: lk_rtc.LeaveRequest(),
       ));