move reference to engine to parent (Participant) class

lib/src/participant/local_participant.dart

@@ -19,8 +19,6 @@ import 'participant.dart';
 
 /// Represents the current participant in the room.
 class LocalParticipant extends Participant {
-  @internal
-  final RTCEngine engine;
   @internal
   final VideoPublishOptions? defaultVideoPublishOptions;
   @internal
@@ -30,14 +28,15 @@ class LocalParticipant extends Participant {
   covariant Map<String, LocalTrackPublication> trackPublications = {};
 
   LocalParticipant({
-    required this.engine,
+    required RTCEngine engine,
     required lk_models.ParticipantInfo info,
     this.defaultVideoPublishOptions,
     this.defaultAudioPublishOptions,
     required EventsEmitter<RoomEvent> roomEvents,
   }) : super(
-          info.sid,
+          engine: engine,
-          info.identity,
+          sid: info.sid,
+          identity: info.identity,
           roomEvents: roomEvents,
         ) {
     updateFromInfo(info);

lib/src/participant/participant.dart

@@ -6,6 +6,7 @@ import '../extensions.dart';
 import '../logger.dart';
 import '../managers/event.dart';
 import '../proto/livekit_models.pb.dart' as lk_models;
+import '../rtc_engine.dart';
 import '../support/disposable.dart';
 import '../track/track.dart';
 import '../publication/track_publication.dart';
@@ -24,6 +25,10 @@ import 'remote_participant.dart';
 /// can not be instantiated directly.
 abstract class Participant extends DisposableChangeNotifier
     with EventsEmittable<ParticipantEvent> {
+  /// Reference to [RTCEngine]
+  @internal
+  final RTCEngine engine;
+
   /// map of track sid => published track
   abstract final Map<String, TrackPublication> trackPublications;
 
@@ -88,9 +93,10 @@ abstract class Participant extends DisposableChangeNotifier
   @internal
   bool get hasInfo => _participantInfo != null;
 
-  Participant(
+  Participant({
-    this.sid,
+    required this.engine,
-    this.identity, {
+    required this.sid,
+    required this.identity,
     required this.roomEvents,
   }) {
     // Any event emitted will trigger ChangeNotifier

lib/src/participant/remote_participant.dart

@@ -18,9 +18,6 @@ import 'participant.dart';
 
 /// Represents other participant in the [Room].
 class RemoteParticipant extends Participant {
-  final RTCEngine _engine;
-  RTCEngine get engine => _engine;
-
   @override
   covariant Map<String, RemoteTrackPublication> trackPublications = {};
 
@@ -40,24 +37,26 @@ class RemoteParticipant extends Participant {
           .whereType<RemoteTrackPublication<RemoteAudioTrack>>()
           .toList();
 
-  RemoteParticipant(
+  RemoteParticipant({
-    this._engine,
+    required RTCEngine engine,
-    String sid,
+    required String sid,
-    String identity, {
+    required String identity,
     required EventsEmitter<RoomEvent> roomEvents,
   }) : super(
-          sid,
+          engine: engine,
-          identity,
+          sid: sid,
+          identity: identity,
           roomEvents: roomEvents,
         );
 
-  RemoteParticipant.fromInfo(
+  RemoteParticipant.fromInfo({
-    this._engine,
+    required RTCEngine engine,
-    lk_models.ParticipantInfo info, {
+    required lk_models.ParticipantInfo info,
     required EventsEmitter<RoomEvent> roomEvents,
   }) : super(
-          info.sid,
+          engine: engine,
-          info.identity,
+          sid: info.sid,
+          identity: info.identity,
           roomEvents: roomEvents,
         ) {
     updateFromInfo(info);

lib/src/room.dart

@@ -235,15 +235,15 @@ class Room extends DisposableChangeNotifier with EventsEmittable<RoomEvent> {
 
     if (info == null) {
       participant = RemoteParticipant(
-        engine,
+        engine: engine,
-        sid,
+        sid: sid,
-        '',
+        identity: '',
         roomEvents: events,
       );
     } else {
       participant = RemoteParticipant.fromInfo(
-        engine,
+        engine: engine,
-        info,
+        info: info,
         roomEvents: events,
       );
     }