newState and oldState on ConnectionStateUpdatedEvent

lib/src/core/engine.dart

@@ -592,7 +592,7 @@ class Engine extends Disposable with EventsEmittable<EngineEvent> {
       events.emit(event);
     })
     ..on<SignalConnectionStateUpdatedEvent>((event) async {
-      if (event.connectionState == ConnectionState.disconnected) {
+      if (event.newState == ConnectionState.disconnected) {
         await _onDisconnected(DisconnectReason.signal);
       }
       // Relay to Room

lib/src/core/signal_client.dart

@@ -152,10 +152,12 @@ class SignalClient extends Disposable with EventsEmittable<SignalEvent> {
     bool didReconnect = _connectionState == ConnectionState.reconnecting &&
         newValue == ConnectionState.connected;
 
+    final oldState = _connectionState;
     _connectionState = newValue;
 
     events.emit(SignalConnectionStateUpdatedEvent(
-      connectionState: _connectionState,
+      newState: _connectionState,
+      oldState: oldState,
       didReconnect: didReconnect,
     ));
   }

lib/src/internal/events.dart

@@ -89,23 +89,41 @@ class SignalJoinResponseEvent with SignalEvent, EngineEvent, InternalEvent {
   });
 }
 
+/// Base class for a ConnectionStateUpdated event
 @internal
-class SignalConnectionStateUpdatedEvent
-    with SignalEvent, EngineEvent, InternalEvent {
-  final ConnectionState connectionState;
+abstract class ConnectionStateUpdatedEvent with EngineEvent, InternalEvent {
+  final ConnectionState newState;
+  final ConnectionState oldState;
   final bool didReconnect;
   final DisconnectReason? disconnectReason;
-  const SignalConnectionStateUpdatedEvent({
-    required this.connectionState,
+  const ConnectionStateUpdatedEvent({
+    required this.newState,
+    required this.oldState,
     required this.didReconnect,
     this.disconnectReason,
   });
   @override
-  String toString() => '$runtimeType(state: ${connectionState.name}, '
+  String toString() => '$runtimeType(newState: ${newState.name}, '
       'didReconnect: ${didReconnect}, '
       'disconnectReason: ${disconnectReason})';
 }
 
+@internal
+class SignalConnectionStateUpdatedEvent extends ConnectionStateUpdatedEvent
+    with SignalEvent {
+  const SignalConnectionStateUpdatedEvent({
+    required ConnectionState newState,
+    required ConnectionState oldState,
+    required bool didReconnect,
+    DisconnectReason? disconnectReason,
+  }) : super(
+          newState: newState,
+          oldState: oldState,
+          didReconnect: didReconnect,
+          disconnectReason: disconnectReason,
+        );
+}
+
 @internal
 class SignalOfferEvent with SignalEvent, InternalEvent {
   final rtc.RTCSessionDescription sd;