better loading indicators for timetables, talk and files

lib/state/app/modules/chatList/bloc/chat_list_bloc.dart

@@ -1,5 +1,6 @@
 import 'package:flutter_app_badge/flutter_app_badge.dart';
 
+import '../../../infrastructure/loadableState/loading_error.dart';
 import '../../../infrastructure/utilityWidgets/loadableHydratedBloc/loadable_hydrated_bloc.dart';
 import '../../../infrastructure/utilityWidgets/loadableHydratedBloc/loadable_hydrated_bloc_event.dart';
 import '../repository/chat_list_repository.dart';
@@ -7,6 +8,14 @@ import 'chat_list_event.dart';
 import 'chat_list_state.dart';
 
 class ChatListBloc extends LoadableHydratedBloc<ChatListEvent, ChatListState, ChatListRepository> {
+  bool _forceRenew = false;
+
+  @override
+  void retry() {
+    _forceRenew = true;
+    super.retry();
+  }
+
   @override
   ChatListRepository repository() => ChatListRepository();
 
@@ -21,15 +30,39 @@ class ChatListBloc extends LoadableHydratedBloc<ChatListEvent, ChatListState, Ch
 
   @override
   Future<void> gatherData() async {
-    final rooms = await repo.data.getRooms();
+    final renew = _forceRenew;
+    _forceRenew = false;
+
+    Object? capturedError;
+    final rooms = await repo.data.getRooms(
+      renew: renew,
+      onError: (e) => capturedError = e,
+    );
     add(DataGathered((s) => s.copyWith(rooms: rooms)));
     _updateAppBadge(rooms);
+
+    if (capturedError != null) throw capturedError!;
   }
 
   Future<void> refresh({bool renew = true}) async {
-    final rooms = await repo.data.getRooms(renew: renew);
-    add(DataGathered((s) => s.copyWith(rooms: rooms)));
-    _updateAppBadge(rooms);
+    add(RefetchStarted<ChatListState>());
+    Object? capturedError;
+    try {
+      final rooms = await repo.data.getRooms(
+        renew: renew,
+        onError: (e) => capturedError = e,
+      );
+      add(DataGathered((s) => s.copyWith(rooms: rooms)));
+      _updateAppBadge(rooms);
+    } catch (e) {
+      capturedError = e;
+    }
+    if (capturedError != null) {
+      add(Error(LoadingError(
+        message: capturedError.toString(),
+        allowRetry: true,
+      )));
+    }
   }
 
   Future<void> createDirectChat(String invite) async {

lib/state/app/modules/chatList/dataProvider/chat_list_data_provider.dart

@@ -1,20 +1,26 @@
-import 'dart:async';
-
 import '../../../../../api/marianumcloud/talk/room/getRoomCache.dart';
 import '../../../../../api/marianumcloud/talk/room/getRoomResponse.dart';
 import '../../../../../api/marianumcloud/talk/createRoom/createRoom.dart';
 import '../../../../../api/marianumcloud/talk/createRoom/createRoomParams.dart';
 
 class ChatListDataProvider {
-  Future<GetRoomResponse> getRooms({bool renew = false}) {
-    final completer = Completer<GetRoomResponse>();
-    GetRoomCache(
+  Future<GetRoomResponse> getRooms({
+    void Function(Object)? onError,
+    bool renew = false,
+  }) async {
+    GetRoomResponse? latest;
+    Object? capturedError;
+    final cache = GetRoomCache(
       renew: renew,
-      onUpdate: (data) {
-        if (!completer.isCompleted) completer.complete(data);
+      onUpdate: (data) => latest = data,
+      onError: (e) {
+        capturedError = e;
+        onError?.call(e);
       },
     );
-    return completer.future;
+    await cache.ready;
+    if (latest != null) return latest!;
+    throw capturedError ?? Exception('No data and no error from getRooms');
   }
 
   Future<void> createDirectRoom(String invite) =>