implemented chat long-polling and optimistic updates, centralized notification management, optimized avatar caching

lib/api/marianumcloud/talk/chat/long_poll_chat.dart

@@ -0,0 +1,69 @@
+import 'dart:async';
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:http/http.dart' as http;
+
+import '../../../errors/network_exception.dart';
+import '../../../errors/server_exception.dart';
+import '../../nextcloud_ocs.dart';
+import 'get_chat_params.dart';
+import 'get_chat_response.dart';
+
+/// Long-poll variant of GetChat (`lookIntoFuture=1`). Bypasses [TalkApi]
+/// because that layer treats non-2xx as errors, and we need 304 to be a
+/// normal "no new messages" outcome. `setReadMarker=on` lets the server
+/// move the read cursor whenever the call returns messages.
+class LongPollChat {
+  final String chatToken;
+  final int lastKnownMessageId;
+  final int timeoutSeconds;
+
+  LongPollChat({
+    required this.chatToken,
+    required this.lastKnownMessageId,
+    this.timeoutSeconds = 30,
+  });
+
+  /// Returns the response, or `null` on HTTP 304 (server timeout, nothing new).
+  Future<GetChatResponse?> run() async {
+    final params = GetChatParams(
+      lookIntoFuture: GetChatParamsSwitch.on,
+      timeout: timeoutSeconds,
+      lastKnownMessageId: lastKnownMessageId,
+      includeLastKnown: GetChatParamsSwitch.off,
+      setReadMarker: GetChatParamsSwitch.on,
+      limit: 100,
+    );
+    final uri = NextcloudOcs.uri(
+      'apps/spreed/api/v1/chat/$chatToken',
+      queryParameters: params.toJson(),
+    );
+    final headers = NextcloudOcs.headers();
+
+    final http.Response response;
+    try {
+      response = await http
+          .get(uri, headers: headers)
+          .timeout(Duration(seconds: timeoutSeconds + 15));
+    } on TimeoutException catch (e) {
+      throw NetworkException.timeout(technicalDetails: 'LongPollChat $uri: $e');
+    } on SocketException catch (e) {
+      throw NetworkException(technicalDetails: 'LongPollChat $uri: ${e.message}');
+    } on http.ClientException catch (e) {
+      throw NetworkException(technicalDetails: 'LongPollChat $uri: ${e.message}');
+    }
+
+    final status = response.statusCode;
+    if (status == 304) return null;
+    if (status >= 200 && status < 300) {
+      final decoded = jsonDecode(response.body) as Map<String, dynamic>;
+      return GetChatResponse.fromJson(decoded['ocs'] as Map<String, dynamic>)
+        ..headers = response.headers;
+    }
+    throw ServerException(
+      statusCode: status,
+      technicalDetails: 'LongPollChat $uri: HTTP $status',
+    );
+  }
+}

lib/api/marianumcloud/talk/set_read_marker/set_read_marker.dart

@@ -26,11 +26,5 @@ class SetReadMarker extends TalkApi {
     Uri uri,
     Object? body,
     Map<String, String>? headers,
-  ) {
-    if (readState) {
-      return http.post(uri, headers: headers);
-    } else {
-      return http.delete(uri, headers: headers);
-    }
-  }
+  ) => readState ? http.post(uri, headers: headers) : http.delete(uri, headers: headers);
 }

lib/app.dart

@@ -36,7 +36,6 @@ class App extends StatefulWidget {
 }
 
 class _AppState extends State<App> with WidgetsBindingObserver {
-  late Timer _refetchChats;
   late Timer _updateTimings;
   StreamSubscription<dynamic>? _timetableWidgetSync;
   // Tracked via the bottom-nav controller's listener so it always reflects the
@@ -45,8 +44,25 @@ class _AppState extends State<App> with WidgetsBindingObserver {
   int _knownTotalTabs = 1;
   bool _userOnLastTab = false;
 
+  static const Duration _chatListActiveInterval = Duration(seconds: 15);
+  static const Duration _chatListIdleInterval = Duration(seconds: 60);
+
   void _onTabControllerChanged() {
     _userOnLastTab = Main.bottomNavigator.index == _knownTotalTabs - 1;
+    _syncChatListPolling();
+  }
+
+  void _syncChatListPolling() {
+    if (!mounted) return;
+    final modules = AppModule.getBottomBarModules(context);
+    final talkSlot = modules.indexWhere((m) => m.module == Modules.talk);
+    final talkIsActive =
+        talkSlot >= 0 && Main.bottomNavigator.index == talkSlot;
+    final bloc = context.read<ChatListBloc>();
+    bloc.setAutoRefreshInterval(
+      talkIsActive ? _chatListActiveInterval : _chatListIdleInterval,
+    );
+    if (talkIsActive) bloc.refresh();
   }
 
   @override
@@ -138,19 +154,13 @@ class _AppState extends State<App> with WidgetsBindingObserver {
       ShareIntentListener.instance.attach();
       ShareIntentListener.pending.addListener(_handlePendingShare);
       _handlePendingShare();
+      _syncChatListPolling();
     });
 
     _updateTimings = Timer.periodic(const Duration(seconds: 30), (_) {
       if (mounted) setState(() {});
     });
 
-    _refetchChats = Timer.periodic(const Duration(seconds: 60), (_) {
-      WidgetsBinding.instance.addPostFrameCallback((_) {
-        if (!mounted) return;
-        context.read<ChatListBloc>().refresh();
-      });
-    });
-
     UpdateUserIndex.index();
 
     if (context.read<SettingsCubit>().val().notificationSettings.enabled) {
@@ -181,7 +191,6 @@ class _AppState extends State<App> with WidgetsBindingObserver {
 
   @override
   void dispose() {
-    _refetchChats.cancel();
     _updateTimings.cancel();
     _timetableWidgetSync?.cancel();
     ShareIntentListener.pending.removeListener(_handlePendingShare);

lib/main.dart

@@ -23,6 +23,7 @@ import 'app.dart';
 import 'background/widget_background_task.dart';
 import 'firebase_options.dart';
 import 'model/account_data.dart';
+import 'routing/app_routes.dart';
 import 'share_intent/share_intent_listener.dart';
 import 'state/app/modules/account/bloc/account_bloc.dart';
 import 'state/app/modules/account/bloc/account_state.dart';
@@ -153,7 +154,9 @@ Future<void> main() async {
         ),
         BlocProvider<BreakerBloc>(create: (_) => BreakerBloc()),
         BlocProvider<ChatListBloc>(create: (_) => ChatListBloc()),
-        BlocProvider<ChatBloc>(create: (_) => ChatBloc()),
+        BlocProvider<ChatBloc>(
+          create: (ctx) => ChatBloc(chatListBloc: ctx.read<ChatListBloc>()),
+        ),
         BlocProvider<TimetableBloc>(create: (_) => TimetableBloc()),
       ],
       child: const Main(),
@@ -199,6 +202,8 @@ class _MainState extends State<Main> {
           checkerboardRasterCacheImages:
               devToolsSettings.checkerboardRasterCacheImages,
           debugShowCheckedModeBanner: false,
+          // Used by ChatView.didPopNext to reclaim the global ChatBloc.
+          navigatorObservers: [AppRoutes.chatRouteObserver],
           localizationsDelegates: const [
             ...GlobalMaterialLocalizations.delegates,
             GlobalWidgetsLocalizations.delegate,

lib/notification/notification_controller.dart

@@ -1,11 +1,19 @@
+import 'dart:async';
+
 import 'package:firebase_messaging/firebase_messaging.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter_bloc/flutter_bloc.dart';
 
+import '../state/app/modules/chat/bloc/chat_bloc.dart';
 import '../widget/debug/debug_tile.dart';
 import '../widget/debug/json_viewer.dart';
 import '../widget/info_dialog.dart';
 import 'notification_tasks.dart';
 
+// `vm:entry-point` on the class so AOT tree-shaking doesn't drop it: the
+// FCM background handler runs in a fresh isolate that looks up the class
+// by name from native code.
+@pragma('vm:entry-point')
 class NotificationController {
   // Notification display is handled by the Firebase SDK using server-generated payloads.
   @pragma('vm:entry-point')
@@ -17,8 +25,21 @@ class NotificationController {
     RemoteMessage message,
     BuildContext context,
   ) async {
-    NotificationTasks.updateProviders(context);
+    final pushToken = _extractChatToken(message);
+    final activeToken = context.read<ChatBloc>().state.data?.currentToken ?? '';
+    final chatIsOpen =
+        pushToken != null && pushToken.isNotEmpty && pushToken == activeToken;
+
     NotificationTasks.updateBadgeCount(message);
+
+    if (chatIsOpen) {
+      // Long-poll already fetches the message and moves the marker; just
+      // dismiss any tray entry that slipped through foreground rendering.
+      unawaited(NotificationTasks.clearNotificationsForChat(pushToken));
+      return;
+    }
+
+    NotificationTasks.updateProviders(context);
   }
 
   static Future<void> onAppOpenedByNotification(

lib/notification/notification_tasks.dart

@@ -1,11 +1,15 @@
+import 'dart:developer';
+
+import 'package:eraser/eraser.dart';
 import 'package:firebase_messaging/firebase_messaging.dart';
 import 'package:flutter/cupertino.dart';
+import 'package:flutter/services.dart';
 import 'package:flutter_app_badge/flutter_app_badge.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 
 import '../routing/app_routes.dart';
-import '../state/app/modules/chat/bloc/chat_bloc.dart';
 import '../state/app/modules/chat_list/bloc/chat_list_bloc.dart';
+import 'notification_service.dart';
 
 class NotificationTasks {
   static void updateBadgeCount(RemoteMessage notification) {
@@ -14,9 +18,43 @@ class NotificationTasks {
     );
   }
 
+  /// Per-chat tag scheme. MUST match the Notify backend, which sets this
+  /// value on `AndroidNotification.setTag` AND `apns-collapse-id`.
+  static String chatTag(String chatToken) => 'talk_$chatToken';
+
+  /// Removes tray notifications belonging to [chatToken]. Eraser handles
+  /// iOS (where the plugin's `getActiveNotifications` returns null ids
+  /// for FCM posts and can't cancel them); the local-notifications sweep
+  /// handles Android and acts as a fallback while Eraser's native side
+  /// isn't built in yet.
+  static Future<void> clearNotificationsForChat(String chatToken) async {
+    final tag = chatTag(chatToken);
+    try {
+      await Eraser.clearAppNotificationsByTag(tag);
+    } on MissingPluginException {
+      // Eraser native code not yet linked — needs flutter clean + run.
+    } on Object catch (e) {
+      log('Eraser($tag) failed: $e');
+    }
+    try {
+      final plugin = NotificationService().flutterLocalNotificationsPlugin;
+      final actives = await plugin.getActiveNotifications();
+      for (final n in actives) {
+        final id = n.id;
+        if (id == null) continue;
+        if (n.tag == tag) await plugin.cancel(id: id, tag: n.tag);
+      }
+    } on Object catch (e) {
+      log('Active-notification sweep failed: $e');
+    }
+  }
+
+  /// Refreshes the chat list. Deliberately does NOT touch [ChatBloc] —
+  /// the open chat view manages its own state via long-poll, and refreshing
+  /// it here would re-fetch the last-opened chat with setReadMarker=on
+  /// even if the user has already left.
   static void updateProviders(BuildContext context) {
     context.read<ChatListBloc>().refresh();
-    context.read<ChatBloc>().refresh();
   }
 
   /// Switches to the Talk tab. If [chatToken] is provided, also schedules

lib/routing/app_routes.dart

@@ -6,6 +6,7 @@ import 'package:persistent_bottom_nav_bar_v2/persistent_bottom_nav_bar_v2.dart';
 import '../api/marianumcloud/talk/room/get_room_response.dart';
 import '../main.dart';
 import '../model/account_data.dart';
+import '../notification/notification_tasks.dart';
 import '../share_intent/pending_share.dart';
 import '../share_intent/remote_file_ref.dart';
 import '../state/app/modules/app_modules.dart';
@@ -39,6 +40,11 @@ class AppRoutes {
   /// by `ChatList` once the matching room is loaded.
   static final ValueNotifier<String?> pendingChatToken = ValueNotifier(null);
 
+  /// Root-navigator observer used by [ChatView] to reclaim the global
+  /// [ChatBloc] on `didPopNext` after a stacked chat is popped.
+  static final RouteObserver<PageRoute<dynamic>> chatRouteObserver =
+      RouteObserver<PageRoute<dynamic>>();
+
   static void openFolder(BuildContext context, List<String> path) {
     pushScreen(context, withNavBar: false, screen: Files(path: path));
   }
@@ -177,6 +183,12 @@ class AppRoutes {
     required UserAvatar avatar,
     bool overrideToSingleSubScreen = true,
   }) {
+    // Local mark only. Server-side mark is sent later from
+    // ChatBloc._loadChat with the freshly-fetched maxId — sending one
+    // here too with the chat list's possibly-stale room.lastMessage.id
+    // would race the fresh one and could regress the server cursor.
+    context.read<ChatListBloc>().markRoomAsRead(room.token, room.lastMessage.id);
+    NotificationTasks.clearNotificationsForChat(room.token);
     TalkNavigator.pushSplitView(
       context,
       ChatView(room: room, selfId: selfId, avatar: avatar),

lib/state/app/modules/chat/bloc/chat_bloc.dart

@@ -1,15 +1,54 @@
+import 'dart:async';
+import 'dart:developer';
+import 'dart:math' as math;
+
+import 'package:flutter/widgets.dart';
+
 import '../../../../../api/errors/error_mapper.dart';
+import '../../../../../api/marianumcloud/talk/chat/get_chat_response.dart';
+import '../../../../../api/marianumcloud/talk/chat/long_poll_chat.dart';
+import '../../../../../api/marianumcloud/talk/room/get_room_response.dart';
+import '../../../../../api/marianumcloud/talk/set_read_marker/set_read_marker.dart';
+import '../../../../../api/marianumcloud/talk/set_read_marker/set_read_marker_params.dart';
 import '../../../infrastructure/loadable_state/loading_error.dart';
 import '../../../infrastructure/utility_widgets/loadable_hydrated_bloc/loadable_hydrated_bloc.dart';
 import '../../../infrastructure/utility_widgets/loadable_hydrated_bloc/loadable_hydrated_bloc_event.dart';
+import '../../chat_list/bloc/chat_list_bloc.dart';
 import '../repository/chat_repository.dart';
 import 'chat_event.dart';
 import 'chat_state.dart';
 
 class ChatBloc
-    extends LoadableHydratedBloc<ChatEvent, ChatState, ChatRepository> {
+    extends LoadableHydratedBloc<ChatEvent, ChatState, ChatRepository>
+    with WidgetsBindingObserver {
+  final ChatListBloc? _chatListBloc;
+
+  String? _pollingToken;
+  int _backoffMs = 0;
+  int _lastKnownMessageId = 0;
+  bool _appResumed = true;
+
+  /// Distinguishes "the bloc tracks a chat the user has open" from "the
+  /// bloc remembers the last opened chat". App-resume only refreshes when
+  /// true — otherwise we'd silently mark a long-since-left chat as read
+  /// on the server. Can't reuse `currentToken` for this signal because
+  /// clearing it on leaveChat raced with setToken-from-didPopNext when
+  /// popping a stacked chat.
+  bool _chatViewActive = false;
+
   DateTime _lastTokenSet = DateTime.fromMillisecondsSinceEpoch(0);
 
+  ChatBloc({ChatListBloc? chatListBloc}) : _chatListBloc = chatListBloc {
+    WidgetsBinding.instance.addObserver(this);
+  }
+
+  @override
+  Future<void> close() {
+    WidgetsBinding.instance.removeObserver(this);
+    _stopLongPoll();
+    return super.close();
+  }
+
   @override
   ChatRepository repository() => ChatRepository();
 
@@ -33,24 +72,74 @@ class ChatBloc
   }
 
   void setToken(String token) {
+    _chatViewActive = true;
     if (token == (innerState?.currentToken ?? '')) {
       refresh();
       return;
     }
+    _stopLongPoll();
     add(Emit((s) => s.copyWith(currentToken: token, chatResponse: null)));
     add(RefetchStarted<ChatState>());
-    _loadChat(token);
-  }
-
-  void setReferenceMessageId(int? messageId) {
-    add(Emit((s) => s.copyWith(referenceMessageId: messageId)));
+    _scheduleLoad(token);
   }
 
   void refresh() {
     final token = innerState?.currentToken ?? '';
     if (token.isEmpty) return;
     add(RefetchStarted<ChatState>());
-    _loadChat(token);
+    _scheduleLoad(token);
+  }
+
+  void setReferenceMessageId(int? messageId) {
+    add(Emit((s) => s.copyWith(referenceMessageId: messageId)));
+  }
+
+  /// Token-aware: only acts when the bloc still points at [fromToken].
+  /// When popping a stacked chat (notification opened B over A), A's
+  /// didPopNext has already run setToken(A) by the time B's dispose
+  /// fires — at that point currentToken is A and we must leave it alone.
+  void leaveChat(String fromToken) {
+    if ((innerState?.currentToken ?? '') != fromToken) return;
+    _chatViewActive = false;
+    _stopLongPoll();
+  }
+
+  /// Fire-and-forget server-side read-marker. Exposed so view-side
+  /// callers (long-press menu, ChatView dispose) hit the same path.
+  Future<void> sendServerReadMarker(String token, int messageId) async {
+    try {
+      await SetReadMarker(
+        token,
+        true,
+        setReadMarkerParams: SetReadMarkerParams(lastReadMessage: messageId),
+      ).run();
+    } on Object catch (e) {
+      log('Server read-marker for $token failed: $e');
+    }
+  }
+
+  @override
+  void didChangeAppLifecycleState(AppLifecycleState state) {
+    final wasResumed = _appResumed;
+    _appResumed = state == AppLifecycleState.resumed;
+    if (!_appResumed) {
+      _stopLongPoll();
+      return;
+    }
+    if (wasResumed) return;
+    final token = innerState?.currentToken ?? '';
+    if (token.isNotEmpty && _chatViewActive) refresh();
+  }
+
+  /// Defer _loadChat by one microtask so the Bloc worker processes the
+  /// preceding Emit/RefetchStarted before any cache/network callback
+  /// fires — otherwise a quick cache hit can run with the previous
+  /// token in state, fail stillCurrent(), and never emit a DataGathered.
+  void _scheduleLoad(String token) {
+    Future<void>.microtask(() {
+      if (isClosed) return;
+      _loadChat(token).then((_) => _startLongPoll(token));
+    });
   }
 
   Future<void> _loadChat(String token) async {
@@ -69,14 +158,21 @@ class ChatBloc
         token: token,
         onCacheData: (data) {
           if (!stillCurrent()) return;
-          // Cache hit: show data immediately but preserve lastFetch — the
-          // cached payload may be stale and we don't want the UI to claim a
-          // fresh fetch just happened.
+          // Only paint cache when the state is empty — restoring a stale
+          // disk snapshot over already-merged long-poll data would visibly
+          // drop those messages until the network call resolves.
+          if (innerState?.chatResponse != null) return;
           add(Emit((s) => s.copyWith(chatResponse: data)));
         },
         onNetworkData: (data) {
+          // Server-side mark runs unconditionally with the freshly-fetched
+          // maxId. Skipping it on stillCurrent==false would leave the
+          // server cursor wherever a quick navigation away left it.
+          final maxId = _maxMessageId(data);
+          if (maxId > 0) unawaited(sendServerReadMarker(token, maxId));
           if (!stillCurrent()) return;
-          add(DataGathered((s) => s.copyWith(chatResponse: data)));
+          _applyChatResponse(data);
+          if (maxId > 0) _chatListBloc?.markRoomAsRead(token, maxId);
         },
         onError: (e) => capturedError = e,
       );
@@ -98,4 +194,115 @@ class ChatBloc
       );
     }
   }
+
+  // ---------------------------------------------------------------------------
+  // Long-poll loop
+  // ---------------------------------------------------------------------------
+
+  void _startLongPoll(String token) {
+    if (!_appResumed) return;
+    if (_pollingToken == token) return;
+    _stopLongPoll();
+    _pollingToken = token;
+    _backoffMs = 0;
+    _lastKnownMessageId = _maxMessageId(innerState?.chatResponse);
+    unawaited(_pollLoop(token));
   }
+
+  void _stopLongPoll() {
+    _pollingToken = null;
+    _backoffMs = 0;
+  }
+
+  Future<void> _pollLoop(String token) async {
+    while (_pollingToken == token && !isClosed) {
+      try {
+        final response = await LongPollChat(
+          chatToken: token,
+          lastKnownMessageId: _lastKnownMessageId,
+        ).run();
+
+        if (_pollingToken != token || isClosed) return;
+        _backoffMs = 0;
+
+        if (response == null) continue;
+
+        final headerId = int.tryParse(
+          response.headers?[_kLongPollLastGivenHeader] ?? '',
+        );
+        if (headerId != null && headerId > _lastKnownMessageId) {
+          _lastKnownMessageId = headerId;
+        }
+
+        if (response.data.isEmpty) continue;
+        _applyChatResponse(response);
+        final maxId = _maxMessageId(response);
+        if (maxId > _lastKnownMessageId) _lastKnownMessageId = maxId;
+        // Long-poll's setReadMarker=on already moved the server cursor;
+        // mirror locally.
+        final preview = _pickDisplayMessage(response);
+        if (preview != null) {
+          _chatListBloc?.applyIncomingMessage(token, preview);
+        } else {
+          _chatListBloc?.markRoomAsRead(token, _lastKnownMessageId);
+        }
+      } on Object catch (e) {
+        if (_pollingToken != token || isClosed) return;
+        log('LongPoll error for $token: $e');
+        _backoffMs = _backoffMs == 0 ? 2000 : math.min(_backoffMs * 2, 30000);
+        await Future.delayed(Duration(milliseconds: _backoffMs));
+      }
+    }
+  }
+
+  /// Merges [incoming] into the existing chatResponse and emits as a
+  /// fresh fetch. Dedups by id (newer wins, so server edits/deletes
+  /// propagate). Shared by initial-load and long-poll so neither wipes
+  /// messages the other already committed.
+  void _applyChatResponse(GetChatResponse incoming) {
+    final current = innerState?.chatResponse;
+    if (current == null) {
+      add(DataGathered((s) => s.copyWith(chatResponse: incoming)));
+      return;
+    }
+    final byId = <int, GetChatResponseObject>{};
+    for (final m in current.data) {
+      byId[m.id] = m;
+    }
+    for (final m in incoming.data) {
+      byId[m.id] = m;
+    }
+    final merged = GetChatResponse(byId.values.toSet())
+      ..headers = incoming.headers;
+    add(DataGathered((s) => s.copyWith(chatResponse: merged)));
+  }
+
+  int _maxMessageId(GetChatResponse? response) {
+    if (response == null) return 0;
+    var max = 0;
+    for (final m in response.data) {
+      if (m.id > max) max = m.id;
+    }
+    return max;
+  }
+
+  /// Highest-id message worth showing as the room preview — comments
+  /// and voice messages, matching what the server picks for `lastMessage`.
+  GetChatResponseObject? _pickDisplayMessage(GetChatResponse response) {
+    GetChatResponseObject? best;
+    for (final m in response.data) {
+      switch (m.messageType) {
+        case GetRoomResponseObjectMessageType.comment:
+        case GetRoomResponseObjectMessageType.voiceMessage:
+          if (best == null || m.id > best.id) best = m;
+        case GetRoomResponseObjectMessageType.deletedComment:
+        case GetRoomResponseObjectMessageType.system:
+        case GetRoomResponseObjectMessageType.command:
+          break;
+      }
+    }
+    return best;
+  }
+}
+
+const _kLongPollLastGivenHeader = 'x-chat-last-given';

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

@@ -1,8 +1,10 @@
+import 'dart:async';
 import 'dart:developer';
 
 import 'package:flutter_app_badge/flutter_app_badge.dart';
 
 import '../../../../../api/errors/error_mapper.dart';
+import '../../../../../api/marianumcloud/talk/chat/get_chat_response.dart';
 import '../../../../../api/marianumcloud/talk/room/get_room_response.dart';
 import '../../../infrastructure/loadable_state/loading_error.dart';
 import '../../../infrastructure/utility_widgets/loadable_hydrated_bloc/loadable_hydrated_bloc.dart';
@@ -15,6 +17,8 @@ class ChatListBloc
     extends
         LoadableHydratedBloc<ChatListEvent, ChatListState, ChatListRepository> {
   bool _forceRenew = false;
+  Timer? _autoRefreshTimer;
+  Duration? _autoRefreshInterval;
 
   @override
   void retry() {
@@ -22,6 +26,27 @@ class ChatListBloc
     super.retry();
   }
 
+  @override
+  Future<void> close() {
+    _autoRefreshTimer?.cancel();
+    return super.close();
+  }
+
+  /// Sets (or clears) the recurring background refresh. Silent so the
+  /// loading bar doesn't blink several times a minute; pull-to-refresh
+  /// and tab-activation refreshes are non-silent for explicit feedback.
+  void setAutoRefreshInterval(Duration? interval) {
+    if (interval == _autoRefreshInterval) return;
+    _autoRefreshInterval = interval;
+    _autoRefreshTimer?.cancel();
+    _autoRefreshTimer = null;
+    if (interval == null) return;
+    _autoRefreshTimer = Timer.periodic(interval, (_) {
+      if (isClosed) return;
+      refresh(silent: true);
+    });
+  }
+
   @override
   ChatListRepository repository() => ChatListRepository();
 
@@ -51,8 +76,8 @@ class ChatListBloc
     if (capturedError != null) throw capturedError!;
   }
 
-  Future<void> refresh({bool renew = true}) async {
-    add(RefetchStarted<ChatListState>());
+  Future<void> refresh({bool renew = true, bool silent = false}) async {
+    if (!silent) add(RefetchStarted<ChatListState>());
     Object? capturedError;
     try {
       final rooms = await repo.data.getRooms(
@@ -82,6 +107,64 @@ class ChatListBloc
     await refresh();
   }
 
+  /// Optimistically clears the unread counter for [token] so the tile
+  /// reacts before a refresh roundtrip lands. Server-side mark-as-read
+  /// is the caller's job (see [ChatBloc.sendServerReadMarker]).
+  void markRoomAsRead(String token, int lastMessageId) {
+    _mutateRoom(token, (r) {
+      if (r.unreadMessages == 0 && r.lastReadMessage >= lastMessageId) {
+        return false;
+      }
+      r.unreadMessages = 0;
+      r.unreadMention = false;
+      r.unreadMentionDirect = false;
+      if (lastMessageId > r.lastReadMessage) r.lastReadMessage = lastMessageId;
+      return true;
+    });
+  }
+
+  /// Pushes a freshly-received message into the matching room tile so the
+  /// list shows the right preview text + activity timestamp before the
+  /// next full refresh lands. Also clears unread because the long-poll
+  /// only feeds this in for an actively-open chat.
+  void applyIncomingMessage(String token, GetChatResponseObject message) {
+    _mutateRoom(token, (r) {
+      final wasRead =
+          r.unreadMessages == 0 && r.lastReadMessage >= message.id;
+      final hasNewer = r.lastMessage.id >= message.id;
+      if (wasRead && hasNewer) return false;
+      r.unreadMessages = 0;
+      r.unreadMention = false;
+      r.unreadMentionDirect = false;
+      if (message.id > r.lastReadMessage) r.lastReadMessage = message.id;
+      if (message.id > r.lastMessage.id) r.lastMessage = message;
+      if (message.timestamp > r.lastActivity) r.lastActivity = message.timestamp;
+      return true;
+    });
+  }
+
+  /// Mutates the room with [token] in-place via [mutator] (returning
+  /// true if anything changed) and re-emits if so. Builds a fresh
+  /// [GetRoomResponse] so equality-by-identity in the bloc state
+  /// recognises the change and rebuilds.
+  void _mutateRoom(
+    String token,
+    bool Function(GetRoomResponseObject room) mutator,
+  ) {
+    final rooms = innerState?.rooms;
+    if (rooms == null) return;
+    var changed = false;
+    final updated = rooms.data.map((r) {
+      if (r.token != token) return r;
+      if (mutator(r)) changed = true;
+      return r;
+    }).toSet();
+    if (!changed) return;
+    final newRooms = GetRoomResponse(updated)..headers = rooms.headers;
+    add(Emit((s) => s.copyWith(rooms: newRooms)));
+    _updateAppBadge(newRooms);
+  }
+
   void _updateAppBadge(GetRoomResponse rooms) {
     try {
       final unread = rooms.data.fold<int>(

lib/view/pages/talk/chat_list.dart

@@ -7,7 +7,6 @@ import '../../../notification/notify_updater.dart';
 import '../../../routing/app_routes.dart';
 import '../../../state/app/infrastructure/loadable_state/loadable_state.dart';
 import '../../../state/app/infrastructure/loadable_state/view/loadable_state_consumer.dart';
-import '../../../state/app/infrastructure/utility_widgets/bloc_module.dart';
 import '../../../state/app/modules/chat_list/bloc/chat_list_bloc.dart';
 import '../../../state/app/modules/chat_list/bloc/chat_list_state.dart';
 import '../../../state/app/modules/settings/bloc/settings_cubit.dart';
@@ -19,15 +18,13 @@ import 'search_chat.dart';
 import 'widgets/chat_tile.dart';
 import 'widgets/split_view_placeholder.dart';
 
+// Reads from the global ChatListBloc in main.dart — re-providing a local
+// one here would shadow it and split the state in two.
 class ChatList extends StatelessWidget {
   const ChatList({super.key});
 
   @override
-  Widget build(BuildContext context) =>
-      BlocModule<ChatListBloc, LoadableState<ChatListState>>(
-        create: (_) => ChatListBloc(),
-        child: (context, bloc, _) => const _ChatListView(),
-      );
+  Widget build(BuildContext context) => const _ChatListView();
 }
 
 class _ChatListView extends StatefulWidget {
@@ -65,14 +62,6 @@ class _ChatListViewState extends State<_ChatListView> {
     final resolved = AppRoutes.resolvePendingChat(context);
     if (resolved == null) return;
     AppRoutes.pendingChatToken.value = null;
-
-    // Replace any chat already pushed on top of the chat list so a freshly
-    // tapped notification doesn't stack indefinitely on previous chats.
-    final navigator = Navigator.of(context);
-    if (navigator.canPop()) {
-      navigator.popUntil((route) => route.isFirst);
-    }
-
     AppRoutes.openChatView(
       context,
       room: resolved.room,
@@ -193,7 +182,14 @@ class _ChatListViewState extends State<_ChatListView> {
                       .talkSettings
                       .drafts
                       .containsKey(room.token);
-                  return ChatTile(data: room, hasDraft: hasDraft);
+                  // Stable key keeps element identity across re-sorts so the
+                  // inner UserAvatar reuses its cached bytes instead of
+                  // flashing on every list update.
+                  return ChatTile(
+                    key: ValueKey(room.token),
+                    data: room,
+                    hasDraft: hasDraft,
+                  );
                 }).toList(),
               );
             },

lib/view/pages/talk/chat_view.dart

@@ -1,3 +1,4 @@
+import 'dart:async';
 import 'dart:math' as math;
 
 import 'package:flutter/material.dart';
@@ -7,9 +8,12 @@ import 'package:scrollable_positioned_list/scrollable_positioned_list.dart';
 import '../../../api/marianumcloud/talk/chat/get_chat_response.dart';
 import '../../../api/marianumcloud/talk/room/get_room_response.dart';
 import '../../../extensions/date_time.dart';
+import '../../../notification/notification_tasks.dart';
+import '../../../routing/app_routes.dart';
 import '../../../state/app/infrastructure/loadable_state/view/loadable_state_consumer.dart';
 import '../../../state/app/modules/chat/bloc/chat_bloc.dart';
 import '../../../state/app/modules/chat/bloc/chat_state.dart';
+import '../../../state/app/modules/chat_list/bloc/chat_list_bloc.dart';
 import '../../../theming/app_theme.dart';
 import '../../../widget/clickable_app_bar.dart';
 import '../../../widget/user_avatar.dart';
@@ -36,7 +40,7 @@ class ChatView extends StatefulWidget {
   State<ChatView> createState() => _ChatViewState();
 }
 
-class _ChatViewState extends State<ChatView> {
+class _ChatViewState extends State<ChatView> with RouteAware {
   final ItemScrollController _itemScrollController = ItemScrollController();
   final TextEditingController _searchTextController = TextEditingController();
   final Map<int, int> _matchIndices = {};
@@ -48,12 +52,73 @@ class _ChatViewState extends State<ChatView> {
   GetChatResponse? _matchesComputedFor;
   String? _matchesComputedQuery;
 
+  // Captured in initState because the framework has unmounted us by the
+  // time dispose runs.
+  ChatBloc? _chatBlocRef;
+  ChatListBloc? _chatListBlocRef;
+  PageRoute<dynamic>? _subscribedRoute;
+
+  @override
+  void initState() {
+    super.initState();
+    _chatBlocRef = context.read<ChatBloc>();
+    _chatListBlocRef = context.read<ChatListBloc>();
+    NotificationTasks.clearNotificationsForChat(widget.room.token);
+  }
+
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    final route = ModalRoute.of(context);
+    if (route is PageRoute && route != _subscribedRoute) {
+      if (_subscribedRoute != null) {
+        AppRoutes.chatRouteObserver.unsubscribe(this);
+      }
+      AppRoutes.chatRouteObserver.subscribe(this, route);
+      _subscribedRoute = route;
+    }
+  }
+
+  @override
+  void didPopNext() {
+    super.didPopNext();
+    // A stacked chat above us was just popped (typical: notification tap
+    // opened another chat). The global ChatBloc currently points at that
+    // other chat's token, so our isReady predicate fails until we re-claim.
+    _chatBlocRef?.setToken(widget.room.token);
+  }
+
   @override
   void dispose() {
+    if (_subscribedRoute != null) {
+      AppRoutes.chatRouteObserver.unsubscribe(this);
+    }
+    _markAsReadFinal();
+    _chatBlocRef?.leaveChat(widget.room.token);
     _searchTextController.dispose();
     super.dispose();
   }
 
+  /// Defensive final mark-as-read so a back-out before the long-poll
+  /// could fire doesn't leave the room as unread. Skipped when the bloc
+  /// has already moved on to another chat — the response data there
+  /// belongs to a different room, and writing its max-id as our marker
+  /// would regress our server cursor.
+  void _markAsReadFinal() {
+    final state = _chatBlocRef?.state.data;
+    if (state == null) return;
+    if (state.currentToken != widget.room.token) return;
+    final response = state.chatResponse;
+    if (response == null) return;
+    var maxId = 0;
+    for (final m in response.data) {
+      if (m.id > maxId) maxId = m.id;
+    }
+    if (maxId == 0) return;
+    _chatListBlocRef?.markRoomAsRead(widget.room.token, maxId);
+    unawaited(_chatBlocRef!.sendServerReadMarker(widget.room.token, maxId));
+  }
+
   @override
   void didUpdateWidget(covariant ChatView oldWidget) {
     super.didUpdateWidget(oldWidget);

lib/view/pages/talk/widgets/chat_tile.dart

@@ -7,9 +7,10 @@ import '../../../../api/marianumcloud/talk/actions/talk_actions.dart';
 import '../../../../api/marianumcloud/talk/chat/rich_object_string_processor.dart';
 import '../../../../api/marianumcloud/talk/room/get_room_response.dart';
 import '../../../../api/marianumcloud/talk/set_read_marker/set_read_marker.dart';
-import '../../../../api/marianumcloud/talk/set_read_marker/set_read_marker_params.dart';
 import '../../../../extensions/date_time.dart';
 import '../../../../model/account_data.dart';
+import '../../../../notification/notification_tasks.dart';
+import '../../../../routing/app_routes.dart';
 import '../../../../state/app/modules/chat/bloc/chat_bloc.dart';
 import '../../../../state/app/modules/chat_list/bloc/chat_list_bloc.dart';
 import '../../../../widget/async_action_button.dart';
@@ -17,7 +18,6 @@ import '../../../../widget/confirm_dialog.dart';
 import '../../../../widget/debug/debug_tile.dart';
 import '../../../../widget/details_bottom_sheet.dart';
 import '../../../../widget/user_avatar.dart';
-import '../chat_view.dart';
 import '../talk_navigator.dart';
 
 class ChatTile extends StatefulWidget {
@@ -61,13 +61,11 @@ class _ChatTileState extends State<ChatTile> {
   void _refreshList() => context.read<ChatListBloc>().refresh();
 
   Future<void> _setCurrentAsRead() async {
-    await SetReadMarker(
-      widget.data.token,
-      true,
-      setReadMarkerParams: SetReadMarkerParams(
-        lastReadMessage: widget.data.lastMessage.id,
-      ),
-    ).run();
+    final token = widget.data.token;
+    final lastId = widget.data.lastMessage.id;
+    context.read<ChatListBloc>().markRoomAsRead(token, lastId);
+    unawaited(NotificationTasks.clearNotificationsForChat(token));
+    await context.read<ChatBloc>().sendServerReadMarker(token, lastId);
     if (!mounted) return;
     _refreshList();
   }
@@ -154,18 +152,17 @@ class _ChatTileState extends State<ChatTile> {
           return;
         }
         if (selfUsername == null) return;
-        unawaited(_setCurrentAsRead());
-        final view = ChatView(
+        // openChatView is the single entry point for opening a chat —
+        // it handles optimistic mark-as-read, tray cleanup, push, and
+        // setToken in one place so the notification-tap path gets the
+        // same treatment as a tile tap.
+        AppRoutes.openChatView(
+          context,
           room: widget.data,
           selfId: selfUsername!,
           avatar: circleAvatar,
-        );
-        TalkNavigator.pushSplitView(
-          context,
-          view,
           overrideToSingleSubScreen: true,
         );
-        context.read<ChatBloc>().setToken(widget.data.token);
       },
       onLongPress: () {
         if (widget.disableContextActions) return;

lib/view/pages/timetable/widgets/appointment_tile.dart

@@ -37,40 +37,10 @@ class AppointmentTile extends StatelessWidget {
                 borderRadius: _radius,
                 color: color,
               ),
-              child: Column(
-                crossAxisAlignment: CrossAxisAlignment.stretch,
-                mainAxisSize: MainAxisSize.max,
-                children: [
-                  _AdaptiveTitle(
-                    text: appointment.subject,
-                    fontSize: kAppointmentTitleFontSize,
-                    minFontSize: kAppointmentTitleMinFontSize,
-                    fontWeight: FontWeight.w500,
-                  ),
-                  if (isCustom) ...[
-                    if (description.isNotEmpty)
-                      Expanded(
-                        child: Padding(
-                          padding: const EdgeInsets.only(top: 1),
-                          child: _WrappingBody(
-                            text: description,
-                            fontSize: kAppointmentBodyFontSize,
-                            lineHeight: kAppointmentBodyLineHeight,
-                          ),
-                        ),
-                      ),
-                  ] else ...[
-                    for (final line
-                        in description
-                            .split('\n')
-                            .where((p) => p.isNotEmpty)
-                            .take(2))
-                      _ScaledLine(
-                        text: line,
-                        fontSize: kAppointmentBodyFontSize,
-                      ),
-                  ],
-                ],
+              child: _TileContent(
+                title: appointment.subject,
+                description: description,
+                isCustom: isCustom,
               ),
             ),
           ),
@@ -96,6 +66,91 @@ class AppointmentTile extends StatelessWidget {
   }
 }
 
+/// Picks how many lines fit into the calendar slot's height. Title gets
+/// first dibs; if not even one minimum-size title line fits, the column
+/// collapses to keep the slot from overflowing.
+class _TileContent extends StatelessWidget {
+  final String title;
+  final String description;
+  final bool isCustom;
+
+  const _TileContent({
+    required this.title,
+    required this.description,
+    required this.isCustom,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final scaler = MediaQuery.textScalerOf(context);
+    final titleLineHeight = scaler.scale(kAppointmentTitleMinFontSize) * 1.1;
+    final bodyLineHeight = scaler.scale(kAppointmentBodyFontSize) * 1.1;
+
+    final titleWidget = _AdaptiveTitle(
+      text: title,
+      fontSize: kAppointmentTitleFontSize,
+      minFontSize: kAppointmentTitleMinFontSize,
+      fontWeight: FontWeight.w500,
+    );
+
+    return LayoutBuilder(
+      builder: (context, constraints) {
+        final available = constraints.maxHeight;
+        // Slot too short for even one min-size title line — drop text
+        // entirely; the coloured rectangle is enough.
+        if (available < titleLineHeight) return const SizedBox.shrink();
+
+        final remaining =
+            (available - titleLineHeight).clamp(0.0, double.infinity);
+        final bodyLineCapacity = (remaining / bodyLineHeight).floor();
+
+        if (isCustom) {
+          if (description.isEmpty || bodyLineCapacity <= 0) {
+            return Column(
+              crossAxisAlignment: CrossAxisAlignment.stretch,
+              mainAxisSize: MainAxisSize.min,
+              children: [titleWidget],
+            );
+          }
+          return Column(
+            crossAxisAlignment: CrossAxisAlignment.stretch,
+            mainAxisSize: MainAxisSize.max,
+            children: [
+              titleWidget,
+              Expanded(
+                child: Padding(
+                  padding: const EdgeInsets.only(top: 1),
+                  child: _WrappingBody(
+                    text: description,
+                    fontSize: kAppointmentBodyFontSize,
+                    lineHeight: kAppointmentBodyLineHeight,
+                  ),
+                ),
+              ),
+            ],
+          );
+        }
+
+        final maxBodyLines = bodyLineCapacity.clamp(0, 2);
+        final lines = description
+            .split('\n')
+            .where((p) => p.isNotEmpty)
+            .take(maxBodyLines)
+            .toList(growable: false);
+        return Column(
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            titleWidget,
+            for (final line in lines)
+              _ScaledLine(text: line, fontSize: kAppointmentBodyFontSize),
+          ],
+        );
+      },
+    );
+  }
+}
+
 /// Renders the appointment title. Scales down to fit the available width via
 /// [FittedBox], but never below [minFontSize] — when even the minimum size
 /// overflows, the text is rendered at [minFontSize] with an ellipsis.

lib/widget/user_avatar.dart

@@ -29,15 +29,18 @@ class _AvatarPayload {
   _AvatarPayload(this.bytes, this.isSvg);
 }
 
-final Map<String, Future<_AvatarPayload?>> _avatarCache = {};
+// Resolved payloads are cached so re-mounts render synchronously; in-flight
+// requests are deduped so concurrent mounts share one HTTP call.
+final Map<String, _AvatarPayload?> _resolvedAvatars = {};
+final Map<String, Future<_AvatarPayload?>> _pendingAvatars = {};
 
 class _UserAvatarState extends State<UserAvatar> {
-  late Future<_AvatarPayload?> _payload;
+  _AvatarPayload? _payload;
 
   @override
   void initState() {
     super.initState();
-    _payload = _load();
+    _attach();
   }
 
   @override
@@ -46,7 +49,7 @@ class _UserAvatarState extends State<UserAvatar> {
     if (oldWidget.id != widget.id ||
         oldWidget.isGroup != widget.isGroup ||
         oldWidget.size != widget.size) {
-      _payload = _load();
+      _attach();
     }
   }
 
@@ -58,9 +61,20 @@ class _UserAvatarState extends State<UserAvatar> {
     return 'https://$host/avatar/${widget.id}/${widget.size}';
   }
 
-  Future<_AvatarPayload?> _load() {
+  void _attach() {
     final url = _url();
-    return _avatarCache.putIfAbsent(url, () => _fetch(url));
+    if (_resolvedAvatars.containsKey(url)) {
+      _payload = _resolvedAvatars[url];
+      return;
+    }
+    _payload = null;
+    final pending = _pendingAvatars.putIfAbsent(url, () => _fetch(url));
+    pending.then((p) {
+      _resolvedAvatars[url] = p;
+      _pendingAvatars.remove(url);
+      if (!mounted || _url() != url) return;
+      setState(() => _payload = p);
+    });
   }
 
   Future<_AvatarPayload?> _fetch(String url) async {
@@ -97,20 +111,11 @@ class _UserAvatarState extends State<UserAvatar> {
   Widget build(BuildContext context) {
     final radius = widget.size.toDouble();
     final theme = Theme.of(context);
-
-    return FutureBuilder<_AvatarPayload?>(
-      future: _payload,
-      builder: (context, snapshot) {
-        final payload = snapshot.data;
+    final payload = _payload;
 
     Widget content;
-        if (payload == null) {
-          content = Icon(
-            widget.isGroup ? Icons.group : Icons.person,
-            size: radius,
-            color: Colors.white,
-          );
-        } else if (payload.isSvg) {
+    if (payload != null) {
+      if (payload.isSvg) {
         content = SvgPicture.memory(
           payload.bytes,
           width: radius * 2,
@@ -126,6 +131,13 @@ class _UserAvatarState extends State<UserAvatar> {
           gaplessPlayback: true,
         );
       }
+    } else {
+      content = Icon(
+        widget.isGroup ? Icons.group : Icons.person,
+        size: radius,
+        color: Colors.white,
+      );
+    }
 
     return CircleAvatar(
       radius: radius,
@@ -139,7 +151,5 @@ class _UserAvatarState extends State<UserAvatar> {
         ),
       ),
     );
-      },
-    );
   }
 }

pubspec.yaml

@@ -40,6 +40,11 @@ dependencies:
   flutter_linkify: ^6.0.0
   linkify: ^5.0.0
   flutter_local_notifications: ^21.0.0
+  # Cancels FCM-rendered notifications by their server-set tag
+  # (Android NotificationManager.cancel, iOS removeDeliveredNotifications via
+  # apns-collapse-id). Used to dismiss a chat's notification when the user
+  # opens or marks the chat read.
+  eraser: ^3.0.0
   scrollable_positioned_list: ^0.3.8
   flutter_split_view: ^0.1.2
   flutter_svg: ^2.0.10