ui: Fix background images not appearing

lib/ui/bloc/conversation_bloc.dart

@@ -45,6 +45,7 @@ class ConversationBloc extends Bloc<ConversationEvent, ConversationState> {
     on<MessageUpdatedEvent>(_onMessageUpdated);
     on<ConversationUpdatedEvent>(_onConversationUpdated);
     on<AppStateChanged>(_onAppStateChanged);
+    on<BackgroundChangedEvent>(_onBackgroundChanged);
   }
 
   void _setLastChangeTimestamp() {
@@ -269,4 +270,8 @@ class ConversationBloc extends Bloc<ConversationEvent, ConversationState> {
       _updateChatState(ChatState.gone);
     }
   }
+
+  Future<void> _onBackgroundChanged(BackgroundChangedEvent event, Emitter<ConversationState> emit) async {
+    return emit(state.copyWith(backgroundPath: event.backgroundPath));
+  }
 }

lib/ui/bloc/conversation_event.dart

@@ -6,7 +6,14 @@ abstract class ConversationEvent {}
 class InitConversationEvent extends ConversationEvent {
   final String backgroundPath;
 
-  InitConversationEvent (this.backgroundPath);
+  InitConversationEvent(this.backgroundPath);
+}
+
+/// Triggered when the background image changed
+class BackgroundChangedEvent extends ConversationEvent {
+  final String backgroundPath;
+
+  BackgroundChangedEvent(this.backgroundPath);
 }
 
 /// Triggered when the content of the input field changed.

lib/ui/bloc/preferences_bloc.dart

@@ -1,3 +1,4 @@
+import "package:moxxyv2/ui/bloc/conversation_bloc.dart";
 import "package:moxxyv2/shared/preferences.dart";
 import "package:moxxyv2/shared/commands.dart";
 import "package:moxxyv2/shared/backgroundsender.dart";
@@ -16,12 +17,19 @@ class PreferencesBloc extends Bloc<PreferencesEvent, PreferencesState> {
     if (event.notify) {
       GetIt.I.get<BackgroundServiceDataSender>().sendData(
         SetPreferencesCommand(
-          preferences: state
+          preferences: event.preferences
         ),
         awaitable: false
       );
     }
 
+    // Notify the conversation UI if we changed the background
+    if (event.preferences.backgroundPath != state.backgroundPath) {
+      GetIt.I.get<ConversationBloc>().add(
+        BackgroundChangedEvent(event.preferences.backgroundPath)
+      );
+    }
+
     emit(event.preferences);
   }
 }

lib/ui/bloc/preferences_event.dart

@@ -9,5 +9,7 @@ class PreferencesChangedEvent extends PreferencesEvent {
   final PreferencesState preferences;
   final bool notify;
 
-  PreferencesChangedEvent(this.preferences, { this.notify = true });
+  PreferencesChangedEvent(this.preferences, {
+      this.notify = true,
+  });
 }