Room recording event (#252)

* feat: Add room reocording reminder.

* chore: comment for recording event.

example/lib/exts.dart

@@ -136,6 +136,23 @@ extension LKExampleExt on BuildContext {
         ),
       );
 
+  Future<bool?> showRecordingStatusChangedDialog(bool isActiveRecording) =>
+      showDialog<bool>(
+        context: this,
+        builder: (ctx) => AlertDialog(
+          title: const Text('Room recording reminder'),
+          content: Text(isActiveRecording
+              ? 'Room recording is active.'
+              : 'Room recording is stoped.'),
+          actions: [
+            TextButton(
+              onPressed: () => Navigator.pop(ctx, true),
+              child: const Text('OK'),
+            ),
+          ],
+        ),
+      );
+
   Future<bool?> showSubscribePermissionDialog() => showDialog<bool>(
         context: this,
         builder: (ctx) => AlertDialog(

example/lib/pages/room.dart

@@ -61,6 +61,9 @@ class _RoomPageState extends State<RoomPage> {
       WidgetsBindingCompatible.instance
           ?.addPostFrameCallback((timeStamp) => Navigator.pop(context));
     })
+    ..on<RoomRecordingStatusChanged>((event) {
+      context.showRecordingStatusChangedDialog(event.activeRecording);
+    })
     ..on<LocalTrackPublishedEvent>((_) => _sortParticipants())
     ..on<LocalTrackUnpublishedEvent>((_) => _sortParticipants())
     ..on<DataReceivedEvent>((event) {

lib/src/core/room.dart

@@ -71,6 +71,9 @@ class Room extends DisposableChangeNotifier with EventsEmittable<RoomEvent> {
   String? get serverRegion => _serverRegion;
   String? _serverRegion;
 
+  bool get isRecording => _isRecording;
+  bool _isRecording = false;
+
   /// a list of participants that are actively speaking, including local participant.
   UnmodifiableListView<Participant> get activeSpeakers =>
       UnmodifiableListView<Participant>(_activeSpeakers);
@@ -154,6 +157,12 @@ class Room extends DisposableChangeNotifier with EventsEmittable<RoomEvent> {
       _serverVersion = event.response.serverVersion;
       _serverRegion = event.response.serverRegion;
 
+      if (_isRecording != event.response.room.activeRecording) {
+        _isRecording = event.response.room.activeRecording;
+        emitWhenConnected(
+            RoomRecordingStatusChanged(activeRecording: _isRecording));
+      }
+
       logger.fine('[Engine] Received JoinResponse, '
           'serverVersion: ${event.response.serverVersion}');
 
@@ -262,6 +271,11 @@ class Room extends DisposableChangeNotifier with EventsEmittable<RoomEvent> {
       _metadata = event.room.metadata;
       emitWhenConnected(
           RoomMetadataChangedEvent(metadata: event.room.metadata));
+      if (_isRecording != event.room.activeRecording) {
+        _isRecording = event.room.activeRecording;
+        emitWhenConnected(
+            RoomRecordingStatusChanged(activeRecording: _isRecording));
+      }
     })
     ..on<SignalConnectionStateUpdatedEvent>((event) {
       // during reconnection, need to send sync state upon signal connection.

lib/src/events.dart

@@ -87,6 +87,19 @@ class RoomMetadataChangedEvent with RoomEvent {
   String toString() => '${runtimeType}()';
 }
 
+/// Room recording status has changed.
+/// Emitted by [Room].
+class RoomRecordingStatusChanged with RoomEvent {
+  final bool activeRecording;
+
+  const RoomRecordingStatusChanged({
+    required this.activeRecording,
+  });
+
+  @override
+  String toString() => '${runtimeType}(activeRecording = $activeRecording)';
+}
+
 /// When a new [RemoteParticipant] joins *after* the current participant has connected
 /// It will not fire for participants that are already in the room
 /// Emitted by [Room].