refactored data providers with centralized cache resolution, unified UI using custom dialogs and bottom sheets, and enhanced network error handling for Dio and TLS errors

lib/api/errors/error_mapper.dart

@@ -1,6 +1,7 @@
 import 'dart:async';
 import 'dart:io';
 
+import 'package:dio/dio.dart';
 import 'package:http/http.dart' as http;
 
 import '../api_error.dart';
@@ -9,10 +10,46 @@ import '../webuntis/webuntis_error.dart';
 import 'app_exception.dart';
 import 'network_exception.dart';
 import 'parse_exception.dart';
+import 'server_exception.dart';
 import 'talk_exception.dart';
 import 'webuntis_exception.dart';
 
 const String _defaultFallback = 'Etwas ist schiefgelaufen. Bitte versuche es erneut.';
+const String _tlsErrorMessage =
+    'Die sichere Verbindung zum Server wurde abgelehnt (Zertifikat oder TLS-Fehler). '
+    'Häufige Ursachen: falsche Geräte-Uhrzeit oder ein WLAN mit Anmeldeseite (z.B. Café/Hotel).';
+
+AppException? _dioToAppException(DioException error) {
+  switch (error.type) {
+    case DioExceptionType.connectionTimeout:
+    case DioExceptionType.sendTimeout:
+    case DioExceptionType.receiveTimeout:
+      return NetworkException.timeout(technicalDetails: error.message);
+    case DioExceptionType.connectionError:
+      return NetworkException(technicalDetails: error.message);
+    case DioExceptionType.badCertificate:
+      return const NetworkException(
+        userMessage: _tlsErrorMessage,
+      );
+    case DioExceptionType.badResponse:
+      final status = error.response?.statusCode;
+      return ServerException(
+        statusCode: status ?? -1,
+        technicalDetails: 'HTTP $status: ${error.message}',
+      );
+    case DioExceptionType.cancel:
+    case DioExceptionType.unknown:
+      final inner = error.error;
+      if (inner is SocketException) return NetworkException(technicalDetails: inner.message);
+      if (inner is HandshakeException) {
+        return const NetworkException(
+          userMessage: _tlsErrorMessage,
+        );
+      }
+      if (inner is FormatException) return ParseException(technicalDetails: inner.message);
+      return null;
+  }
+}
 
 String errorToUserMessage(Object? error, {String fallback = _defaultFallback}) {
   if (error == null) return fallback;
@@ -21,6 +58,11 @@ String errorToUserMessage(Object? error, {String fallback = _defaultFallback}) {
   if (error is TalkError) return TalkException(error).userMessage;
   if (error is WebuntisError) return WebuntisException(error).userMessage;
 
+  if (error is DioException) {
+    final mapped = _dioToAppException(error);
+    if (mapped != null) return mapped.userMessage;
+  }
+
   if (error is SocketException) {
     return const NetworkException().userMessage;
   }
@@ -31,7 +73,7 @@ String errorToUserMessage(Object? error, {String fallback = _defaultFallback}) {
     return const NetworkException().userMessage;
   }
   if (error is HandshakeException) {
-    return 'Sichere Verbindung konnte nicht hergestellt werden.';
+    return _tlsErrorMessage;
   }
   if (error is FormatException) {
     return const ParseException().userMessage;
@@ -48,12 +90,20 @@ String? errorToTechnicalDetails(Object? error) {
   if (error is AppException) return error.technicalDetails ?? error.toString();
   if (error is TalkError) return TalkException(error).technicalDetails;
   if (error is WebuntisError) return WebuntisException(error).technicalDetails;
+  if (error is DioException) {
+    final mapped = _dioToAppException(error);
+    if (mapped != null) return mapped.technicalDetails ?? mapped.toString();
+  }
   return error.toString();
 }
 
 bool errorAllowsRetry(Object? error) {
   if (error == null) return true;
   if (error is AppException) return error.allowRetry;
+  if (error is DioException) {
+    final mapped = _dioToAppException(error);
+    if (mapped != null) return mapped.allowRetry;
+  }
   return true;
 }
 

lib/api/holidays/get_holidays.dart

@@ -1,16 +0,0 @@
-import 'dart:convert';
-import 'package:http/http.dart' as http;
-
-import 'get_holidays_response.dart';
-
-class GetHolidays {
-  Future<GetHolidaysResponse> query() async {
-    var response = (await http.get(Uri.parse('https://ferien-api.de/api/v1/holidays/HE'))).body;
-    var data = jsonDecode(response) as List<dynamic>;
-    return GetHolidaysResponse(
-        List<GetHolidaysResponseObject>.from(
-            data.map<GetHolidaysResponseObject>((e) => GetHolidaysResponseObject.fromJson(e as Map<String, dynamic>))
-        )
-    );
-  }
-}

lib/api/holidays/get_holidays_cache.dart

@@ -1,18 +0,0 @@
-import '../request_cache.dart';
-import 'get_holidays.dart';
-import 'get_holidays_response.dart';
-
-class GetHolidaysCache extends SimpleCache<GetHolidaysResponse> {
-  GetHolidaysCache({super.onUpdate, super.renew})
-      : super(
-          cacheTime: RequestCache.cacheDay,
-          loader: () => GetHolidays().query(),
-          fromJson: (json) => GetHolidaysResponse(
-            (json['data'] as List)
-                .map((i) => GetHolidaysResponseObject.fromJson(i as Map<String, dynamic>))
-                .toList(),
-          ),
-        ) {
-    start('state-holidays');
-  }
-}

lib/api/holidays/get_holidays_response.dart

@@ -1,38 +0,0 @@
-
-import 'package:json_annotation/json_annotation.dart';
-
-import '../api_response.dart';
-
-part 'get_holidays_response.g.dart';
-
-@JsonSerializable(explicitToJson: true)
-class GetHolidaysResponse extends ApiResponse {
-  List<GetHolidaysResponseObject> data;
-
-  GetHolidaysResponse(this.data);
-
-  factory GetHolidaysResponse.fromJson(Map<String, dynamic> json) => _$GetHolidaysResponseFromJson(json);
-  Map<String, dynamic> toJson() => _$GetHolidaysResponseToJson(this);
-}
-
-@JsonSerializable()
-class GetHolidaysResponseObject {
-  String start;
-  String end;
-  int year;
-  String stateCode;
-  String name;
-  String slug;
-
-  GetHolidaysResponseObject({
-    required this.start,
-    required this.end,
-    required this.year,
-    required this.stateCode,
-    required this.name,
-    required this.slug
-  });
-
-  factory GetHolidaysResponseObject.fromJson(Map<String, dynamic> json) => _$GetHolidaysResponseObjectFromJson(json);
-  Map<String, dynamic> toJson() => _$GetHolidaysResponseObjectToJson(this);
-}

lib/api/holidays/get_holidays_response.g.dart

@@ -1,49 +0,0 @@
-// GENERATED CODE - DO NOT MODIFY BY HAND
-
-part of 'get_holidays_response.dart';
-
-// **************************************************************************
-// JsonSerializableGenerator
-// **************************************************************************
-
-GetHolidaysResponse _$GetHolidaysResponseFromJson(Map<String, dynamic> json) =>
-    GetHolidaysResponse(
-        (json['data'] as List<dynamic>)
-            .map(
-              (e) =>
-                  GetHolidaysResponseObject.fromJson(e as Map<String, dynamic>),
-            )
-            .toList(),
-      )
-      ..headers = (json['headers'] as Map<String, dynamic>?)?.map(
-        (k, e) => MapEntry(k, e as String),
-      );
-
-Map<String, dynamic> _$GetHolidaysResponseToJson(
-  GetHolidaysResponse instance,
-) => <String, dynamic>{
-  'headers': ?instance.headers,
-  'data': instance.data.map((e) => e.toJson()).toList(),
-};
-
-GetHolidaysResponseObject _$GetHolidaysResponseObjectFromJson(
-  Map<String, dynamic> json,
-) => GetHolidaysResponseObject(
-  start: json['start'] as String,
-  end: json['end'] as String,
-  year: (json['year'] as num).toInt(),
-  stateCode: json['stateCode'] as String,
-  name: json['name'] as String,
-  slug: json['slug'] as String,
-);
-
-Map<String, dynamic> _$GetHolidaysResponseObjectToJson(
-  GetHolidaysResponseObject instance,
-) => <String, dynamic>{
-  'start': instance.start,
-  'end': instance.end,
-  'year': instance.year,
-  'stateCode': instance.stateCode,
-  'name': instance.name,
-  'slug': instance.slug,
-};

lib/api/marianumcloud/nextcloud_ocs.dart

@@ -1,27 +1,17 @@
 import '../../model/account_data.dart';
 import '../../model/endpoint_data.dart';
 
-/// Shared helpers for Nextcloud OCS v2 endpoints.
+/// Shared headers and URI builder for Nextcloud OCS v2 endpoints. Used by
-///
+/// TalkApi, AutocompleteApi, FileSharingApi.
-/// Three call sites previously duplicated the same header dictionary and the
-/// same URI scaffolding (TalkApi, AutocompleteApi, FileSharingApi). Anything
-/// that talks to `https://<domain>/<base>/ocs/v2.php/...` should go through
-/// these two helpers so additions like a new header or a different auth
-/// scheme only need to change here.
 class NextcloudOcs {
   NextcloudOcs._();
 
-  /// The standard OCS request header set: JSON accept, OCS API marker,
-  /// HTTP Basic auth from the active [AccountData].
   static Map<String, String> headers() => {
         'Accept': 'application/json',
         'OCS-APIRequest': 'true',
         'Authorization': AccountData().getBasicAuthHeader(),
       };
 
-  /// Builds an OCS URI by appending [pathSuffix] under `/ocs/v2.php/` of
-  /// the configured Nextcloud endpoint. Query parameters are converted to
-  /// strings (Uri rejects non-string values).
   static Uri uri(String pathSuffix, {Map<String, dynamic>? queryParameters}) {
     final endpoint = EndpointData().nextcloud();
     return Uri.https(

lib/api/marianumcloud/talk/room/get_room_response.dart

@@ -120,38 +120,6 @@ enum GetRoomResponseObjectParticipantNotificationLevel {
   @JsonValue(3) neverNotify,
 }
 
-// @JsonSerializable(explicitToJson: true)
-// class GetRoomResponseObjectMessage {
-//   int id;
-//   String token;
-//   GetRoomResponseObjectMessageActorType actorType;
-//   String actorId;
-//   String actorDisplayName;
-//   int timestamp;
-//   String message;
-//   String systemMessage;
-//   GetRoomResponseObjectMessageType messageType;
-//   bool isReplyable;
-//   String referenceId;
-//
-//
-//   GetRoomResponseObjectMessage(
-//       this.id,
-//       this.token,
-//       this.actorType,
-//       this.actorId,
-//       this.actorDisplayName,
-//       this.timestamp,
-//       this.message,
-//       this.systemMessage,
-//       this.messageType,
-//       this.isReplyable,
-//       this.referenceId);
-//
-//   factory GetRoomResponseObjectMessage.fromJson(Map<String, dynamic> json) => _$GetRoomResponseObjectMessageFromJson(json);
-//   Map<String, dynamic> toJson() => _$GetRoomResponseObjectMessageToJson(this);
-// }
-
 enum GetRoomResponseObjectMessageActorType {
   @JsonValue('deleted_users') deletedUsers,
   @JsonValue('users') user,

lib/api/request_cache.dart

@@ -4,6 +4,7 @@ import 'dart:convert';
 import 'package:localstore/localstore.dart';
 
 import 'api_response.dart';
+import 'errors/parse_exception.dart';
 
 abstract class RequestCache<T extends ApiResponse?> {
   static const int cacheNothing = 0;
@@ -81,10 +82,8 @@ abstract class RequestCache<T extends ApiResponse?> {
 
 }
 
-/// Concrete [RequestCache] that delegates the two overrides to functions
+/// Concrete [RequestCache] that takes the two overrides as constructor
-/// passed in the constructor. Used to collapse the dozens of one-class-per-
+/// callbacks instead of requiring a subclass per endpoint.
-/// endpoint cache files that all just forward to `<Endpoint>().run()` and
-/// `<Response>.fromJson(jsonDecode(...))`.
 class SimpleCache<T extends ApiResponse?> extends RequestCache<T> {
   final Future<T> Function() _loader;
   final T Function(Map<String, dynamic> json) _fromJson;
@@ -115,3 +114,30 @@ class SimpleCache<T extends ApiResponse?> extends RequestCache<T> {
   @override
   T onLocalData(String json) => _fromJson(jsonDecode(json) as Map<String, dynamic>);
 }
+
+/// Captures the latest cache payload (cached or network) and rethrows the
+/// captured network error if no payload arrived. Collapses the
+/// `latest`/`capturedError`/`await ready` boilerplate that DataProviders
+/// otherwise repeat per endpoint.
+Future<T> resolveFromCache<T extends ApiResponse?>(
+  RequestCache<T> Function(void Function(T) onUpdate, void Function(Exception) onError) build, {
+  void Function(Object)? onError,
+  String? operationName,
+}) async {
+  T? latest;
+  Object? capturedError;
+  final cache = build(
+    (data) => latest = data,
+    (e) {
+      capturedError = e;
+      onError?.call(e);
+    },
+  );
+  await cache.ready;
+  if (latest != null) return latest as T;
+  final err = capturedError;
+  if (err != null) throw err;
+  throw ParseException(
+    technicalDetails: operationName != null ? 'No data and no error from $operationName' : null,
+  );
+}

lib/notification/notification_controller.dart

@@ -3,6 +3,7 @@ import 'package:flutter/material.dart';
 
 import '../widget/debug/debug_tile.dart';
 import '../widget/debug/json_viewer.dart';
+import '../widget/info_dialog.dart';
 import 'notification_tasks.dart';
 
 class NotificationController {
@@ -22,16 +23,13 @@ class NotificationController {
     NotificationTasks.updateProviders(context);
 
     DebugTile(context).run(() {
-      showDialog(context: context, builder: (context) => AlertDialog(
+      InfoDialog.show(
-        title: const Text('Notification report'),
+        context,
-        content: Column(
+        'Dieser Bericht wird angezeigt, da du den Entwicklermodus aktiviert hast und die App über eine Benachrichtigung geöffnet wurde.\n\n'
-          mainAxisSize: MainAxisSize.min,
+            '${JsonViewer.format(message.data)}',
-          children: [
+        copyable: true,
-            const Text('Dieser Bericht wird angezeigt, da du den Entwicklermodus aktiviert hast und die App über eine Benachrichtigung geöffnet wurde.'),
+        title: 'Notification report',
-            Text(JsonViewer.format(message.data)),
+      );
-          ],
-        ),
-      ));
     });
   }
 

lib/routing/app_routes.dart

@@ -25,22 +25,15 @@ import '../widget/debug/cache_view.dart';
 import '../widget/file_viewer.dart';
 import '../widget/user_avatar.dart';
 
-/// Single entry point for full-page navigations across the app.
+/// Single entry point for full-page navigations. Dialogs and bottom sheets
-///
+/// stay at the call sites; only full-page pushes go through here.
-/// Every full-page push in modules should go through one of these methods.
-/// Dialogs (`showDialog`), bottom sheets (`showStickyFlexibleBottomSheet`,
-/// `showDetailsBottomSheet`), and `Navigator.pop` for closing those
-/// remain unchanged and live at the call sites.
 class AppRoutes {
   AppRoutes._();
 
-  /// Token of a chat that should be auto-opened in the Talk tab once
+  /// Set by [openChatByToken] (e.g. from a tapped notification) and consumed
-  /// the chat list view picks it up. Set by [openChatByToken] (e.g. from
+  /// by `ChatList` once the matching room is loaded.
-  /// a tapped notification) and consumed by the `ChatList` widget.
   static final ValueNotifier<String?> pendingChatToken = ValueNotifier(null);
 
-  // -- Files --------------------------------------------------------------
-
   static void openFolder(BuildContext context, List<String> path) {
     pushScreen(context, withNavBar: false, screen: Files(path: path));
   }
@@ -53,14 +46,10 @@ class AppRoutes {
     );
   }
 
-  // -- Timetable ----------------------------------------------------------
-
   static void openCustomEvents(BuildContext context) {
     pushScreen(context, withNavBar: false, screen: const CustomEventsView());
   }
 
-  // -- Marianum Message ---------------------------------------------------
-
   static void openMarianumMessage(BuildContext context, String basePath, MarianumMessage message) {
     pushScreen(
       context,
@@ -69,8 +58,6 @@ class AppRoutes {
     );
   }
 
-  // -- Sharing / Settings / Feedback / DevTools ---------------------------
-
   static void openQrShare(BuildContext context) {
     pushScreen(context, withNavBar: false, screen: const QrShareView());
   }
@@ -95,8 +82,6 @@ class AppRoutes {
     pushScreen(context, withNavBar: false, screen: const Roomplan());
   }
 
-  // -- Talk ---------------------------------------------------------------
-
   static void openMessageReactions(BuildContext context, String token, int messageId) {
     pushScreen(
       context,
@@ -105,8 +90,6 @@ class AppRoutes {
     );
   }
 
-  /// Opens a chat from a known [GetRoomResponseObject]. Delegates to
-  /// [TalkNavigator.pushSplitView] so tablet split-view behaviour stays intact.
   static void openChatView(
     BuildContext context, {
     required GetRoomResponseObject room,
@@ -122,9 +105,8 @@ class AppRoutes {
     context.read<ChatBloc>().setToken(room.token);
   }
 
-  /// Schedules a chat to be opened in the Talk tab. Use this when only the
+  /// Schedules a chat to be opened in the Talk tab once the room is loaded.
-  /// token is known (e.g. from a tapped notification) — the actual push
+  /// Use when only the token is known (e.g. from a tapped notification).
-  /// happens inside the `ChatList` widget once the room is available.
   static void openChatByToken(BuildContext context, String token) {
     pendingChatToken.value = token;
     goToTalkTab(context);
@@ -135,11 +117,9 @@ class AppRoutes {
     }
   }
 
-  /// Resolves a pending chat token (set via [openChatByToken]) using the
+  /// Resolves a pending chat token (set via [openChatByToken]). Returns null
-  /// [ChatListBloc]'s current rooms and the active [AccountData] credentials.
+  /// if the room or account is not ready yet — callers should retry when
-  /// Returns `null` if the token cannot yet be matched (e.g. the room is
+  /// [pendingChatToken] or the bloc state change.
-  /// still being loaded). Callers should keep listening to [pendingChatToken]
-  /// and the bloc state and retry when either changes.
   static ResolvedPendingChat? resolvePendingChat(BuildContext context) {
     final token = pendingChatToken.value;
     if (token == null) return null;
@@ -166,17 +146,14 @@ class AppRoutes {
     return null;
   }
 
-  // -- Module / Tab navigation -------------------------------------------
+  /// Pushes a module from the "Mehr" tab list. Modules already in the bottom
-
+  /// bar are switched to via [goToTab] instead.
-  /// Opens an [AppModule]'s root view as a full screen push (used by the
-  /// "Mehr" tab list). Modules that live in the bottom bar are reached via
-  /// [goToTab] instead.
   static void openModule(BuildContext context, AppModule module) {
     pushScreen(context, withNavBar: false, screen: module.create());
   }
 
-  /// Switches the bottom navigation to the given [module] if it is currently
+  /// Switches the bottom navigation to [module]. Returns false when the
-  /// in the bottom bar. Returns `true` if the jump happened.
+  /// module is not currently in the bottom bar.
   static bool goToTab(BuildContext context, Modules module) {
     final index = AppModule.getBottomBarModules(context)
         .map((e) => e.module)
@@ -187,8 +164,6 @@ class AppRoutes {
     return true;
   }
 
-  /// Convenience wrapper for the Talk tab — preserved for the notification
-  /// handler API which only knows about Talk.
   static void goToTalkTab(BuildContext context) {
     goToTab(context, Modules.talk);
   }

lib/state/app/infrastructure/data_loader/data_loader.dart

@@ -12,21 +12,15 @@ abstract class DataLoader<TResult> {
   }
 
   Future<TResult> run() async {
-    var fetcher = fetch();
+    final response = await fetch();
-    await Future.wait([
-      fetcher,
-      Future.delayed(const Duration(milliseconds: 500)) // TODO tune or remove
-    ]);
-
-    var response = await fetcher;
     try {
       return assemble(DataLoaderResult(
         json: jsonDecode(response.data!),
         headers: response.headers.map.map((key, value) => MapEntry(key, value.join(';'))),
       ));
-    } catch(trace, e) {
+    } catch (e, stack) {
-      log(trace.toString());
+      log('DataLoader assemble failed', error: e, stackTrace: stack);
-      throw e;
+      rethrow;
     }
   }
 

lib/state/app/modules/chat_list/data_provider/chat_list_data_provider.dart

@@ -2,26 +2,22 @@ import '../../../../../api/marianumcloud/talk/create_room/create_room.dart';
 import '../../../../../api/marianumcloud/talk/create_room/create_room_params.dart';
 import '../../../../../api/marianumcloud/talk/room/get_room_cache.dart';
 import '../../../../../api/marianumcloud/talk/room/get_room_response.dart';
+import '../../../../../api/request_cache.dart';
 
 class ChatListDataProvider {
   Future<GetRoomResponse> getRooms({
     void Function(Object)? onError,
     bool renew = false,
-  }) async {
+  }) =>
-    GetRoomResponse? latest;
+      resolveFromCache<GetRoomResponse>(
-    Object? capturedError;
+        (onUpdate, onError) => GetRoomCache(
-    final cache = GetRoomCache(
           renew: renew,
-      onUpdate: (data) => latest = data,
+          onUpdate: onUpdate,
-      onError: (e) {
+          onError: onError,
-        capturedError = e;
+        ),
-        onError?.call(e);
+        onError: onError,
-      },
+        operationName: 'getRooms',
       );
-    await cache.ready;
-    if (latest != null) return latest!;
-    throw capturedError ?? Exception('No data and no error from getRooms');
-  }
 
   Future<void> createDirectRoom(String invite) =>
       CreateRoom(CreateRoomParams(roomType: 1, invite: invite)).run();

lib/state/app/modules/files/data_provider/files_data_provider.dart

@@ -3,6 +3,7 @@ import 'package:nextcloud/nextcloud.dart';
 import '../../../../../api/marianumcloud/webdav/queries/list_files/list_files_cache.dart';
 import '../../../../../api/marianumcloud/webdav/queries/list_files/list_files_response.dart';
 import '../../../../../api/marianumcloud/webdav/webdav_api.dart';
+import '../../../../../api/request_cache.dart';
 
 class FilesDataProvider {
   /// Lists files at [path]. Cached payload is delivered via [onCacheData] as
@@ -14,22 +15,17 @@ class FilesDataProvider {
     String path, {
     void Function(ListFilesResponse)? onCacheData,
     void Function(Object)? onError,
-  }) async {
+  }) =>
-    ListFilesResponse? latest;
+      resolveFromCache<ListFilesResponse>(
-    Object? capturedError;
+        (onUpdate, onError) => ListFilesCache(
-    final cache = ListFilesCache(
           path: path,
-      onUpdate: (data) => latest = data,
+          onUpdate: onUpdate,
           onCacheData: onCacheData,
-      onError: (e) {
+          onError: onError,
-        capturedError = e;
+        ),
-        onError?.call(e);
+        onError: onError,
-      },
+        operationName: 'listFiles',
       );
-    await cache.ready;
-    if (latest != null) return latest!;
-    throw capturedError ?? Exception('No data and no error from listFiles');
-  }
 
   Future<void> createFolder(String fullPath) async {
     final webdav = await WebdavApi.webdav;

lib/state/app/modules/timetable/data_provider/timetable_data_provider.dart

@@ -10,6 +10,7 @@ import '../../../../../api/mhsl/custom_timetable_event/remove/remove_custom_time
 import '../../../../../api/mhsl/custom_timetable_event/remove/remove_custom_timetable_event_params.dart';
 import '../../../../../api/mhsl/custom_timetable_event/update/update_custom_timetable_event.dart';
 import '../../../../../api/mhsl/custom_timetable_event/update/update_custom_timetable_event_params.dart';
+import '../../../../../api/request_cache.dart';
 import '../../../../../api/webuntis/queries/get_holidays/get_holidays_cache.dart';
 import '../../../../../api/webuntis/queries/get_holidays/get_holidays_response.dart';
 import '../../../../../api/webuntis/queries/get_rooms/get_rooms_cache.dart';
@@ -30,112 +31,84 @@ class TimetableDataProvider {
     DateTime endDate, {
     void Function(Object)? onError,
     bool renew = false,
-  }) async {
+  }) =>
-    GetTimetableResponse? latest;
+      resolveFromCache<GetTimetableResponse>(
-    Object? capturedError;
+        (onUpdate, onError) => GetTimetableCache(
-    final cache = GetTimetableCache(
           startdate: int.parse(_dateFormat.format(startDate)),
           enddate: int.parse(_dateFormat.format(endDate)),
           renew: renew,
-      onUpdate: (data) => latest = data,
+          onUpdate: onUpdate,
-      onError: (e) {
+          onError: onError,
-        capturedError = e;
+        ),
-        onError?.call(e);
+        onError: onError,
-      },
+        operationName: 'getWeek',
       );
-    await cache.ready;
-    if (latest != null) return latest!;
-    throw capturedError ?? Exception('No data and no error from getWeek');
-  }
 
   Future<GetRoomsResponse> getRooms({
     void Function(Object)? onError,
     bool renew = false,
-  }) async {
+  }) =>
-    GetRoomsResponse? latest;
+      resolveFromCache<GetRoomsResponse>(
-    Object? capturedError;
+        (onUpdate, onError) => GetRoomsCache(
-    final cache = GetRoomsCache(
           renew: renew,
-      onUpdate: (data) => latest = data,
+          onUpdate: onUpdate,
-      onError: (e) {
+          onError: onError,
-        capturedError = e;
+        ),
-        onError?.call(e);
+        onError: onError,
-      },
+        operationName: 'getRooms',
       );
-    await cache.ready;
-    if (latest != null) return latest!;
-    throw capturedError ?? Exception('No data and no error from getRooms');
-  }
 
   Future<GetSubjectsResponse> getSubjects({
     void Function(Object)? onError,
     bool renew = false,
-  }) async {
+  }) =>
-    GetSubjectsResponse? latest;
+      resolveFromCache<GetSubjectsResponse>(
-    Object? capturedError;
+        (onUpdate, onError) => GetSubjectsCache(
-    final cache = GetSubjectsCache(
           renew: renew,
-      onUpdate: (data) => latest = data,
+          onUpdate: onUpdate,
-      onError: (e) {
+          onError: onError,
-        capturedError = e;
+        ),
-        onError?.call(e);
+        onError: onError,
-      },
+        operationName: 'getSubjects',
       );
-    await cache.ready;
-    if (latest != null) return latest!;
-    throw capturedError ?? Exception('No data and no error from getSubjects');
-  }
 
   Future<GetHolidaysResponse> getSchoolHolidays({
     void Function(Object)? onError,
     bool renew = false,
-  }) async {
+  }) =>
-    GetHolidaysResponse? latest;
+      resolveFromCache<GetHolidaysResponse>(
-    Object? capturedError;
+        (onUpdate, onError) => GetHolidaysCache(
-    final cache = GetHolidaysCache(
           renew: renew,
-      onUpdate: (data) => latest = data,
+          onUpdate: onUpdate,
-      onError: (e) {
+          onError: onError,
-        capturedError = e;
+        ),
-        onError?.call(e);
+        onError: onError,
-      },
+        operationName: 'getSchoolHolidays',
       );
-    await cache.ready;
-    if (latest != null) return latest!;
-    throw capturedError ?? Exception('No data and no error from getSchoolHolidays');
-  }
 
-  Future<GetTimegridUnitsResponse> getTimegrid({bool renew = false}) async {
+  Future<GetTimegridUnitsResponse> getTimegrid({bool renew = false}) =>
-    GetTimegridUnitsResponse? latest;
+      resolveFromCache<GetTimegridUnitsResponse>(
-    Object? capturedError;
+        (onUpdate, _) => GetTimegridUnitsCache(
-    final cache = GetTimegridUnitsCache(
           renew: renew,
-      onUpdate: (data) => latest = data,
+          onUpdate: onUpdate,
+        ),
+        operationName: 'getTimegrid',
       );
-    await cache.ready;
-    if (latest != null) return latest!;
-    throw capturedError ?? Exception('No data and no error from getTimegrid');
-  }
 
   Future<GetCustomTimetableEventResponse> getCustomEvents({
     bool renew = false,
     void Function(Object)? onError,
-  }) async {
+  }) =>
-    GetCustomTimetableEventResponse? latest;
+      resolveFromCache<GetCustomTimetableEventResponse>(
-    Object? capturedError;
+        (onUpdate, onError) => GetCustomTimetableEventCache(
-    final cache = GetCustomTimetableEventCache(
           GetCustomTimetableEventParams(AccountData().getUserSecret()),
           renew: renew,
-      onUpdate: (data) => latest = data,
+          onUpdate: onUpdate,
-      onError: (e) {
+          onError: onError,
-        capturedError = e;
+        ),
-        onError?.call(e);
+        onError: onError,
-      },
+        operationName: 'getCustomEvents',
       );
-    await cache.ready;
-    if (latest != null) return latest!;
-    throw capturedError ?? Exception('No data and no error from getCustomEvents');
-  }
 
   Future<void> addCustomEvent(CustomTimetableEvent event) =>
       AddCustomTimetableEvent(AddCustomTimetableEventParams(AccountData().getUserSecret(), event)).run();

lib/utils/clipboard_helper.dart

@@ -1,8 +1,7 @@
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 
-/// Copies [text] to the system clipboard and shows a SnackBar confirmation.
+/// Copies [text] to the system clipboard and shows a SnackBar.
-/// Safe to await: respects context lifecycle via the provided [context].
 Future<void> copyToClipboard(
   BuildContext context,
   String text, {

lib/view/pages/files/files_upload_dialog.dart

@@ -7,6 +7,7 @@ import 'package:nextcloud/nextcloud.dart';
 import '../../../api/marianumcloud/webdav/webdav_api.dart';
 import '../../../widget/confirm_dialog.dart';
 import '../../../widget/focus_behaviour.dart';
+import '../../../widget/info_dialog.dart';
 
 class FilesUploadDialog extends StatefulWidget {
   final List<String> filePaths;
@@ -48,19 +49,11 @@ class _FilesUploadDialogState extends State<FilesUploadDialog> {
   }
 
   void showHttpErrorCode(int httpErrorCode) {
-    showDialog(
+    InfoDialog.show(
-      context: context,
+      context,
-      builder: (BuildContext context) => AlertDialog(
+      'Error code: $httpErrorCode',
-          title: const Text('Ein Fehler ist aufgetreten'),
+      title: 'Ein Fehler ist aufgetreten',
-          contentPadding: const EdgeInsets.all(10),
+      copyable: true,
-          content: Text('Error code: $httpErrorCode'),
-          actions: [
-            TextButton(
-              onPressed: () => Navigator.of(context).pop(),
-              child: const Text('Schließen', textAlign: TextAlign.center),
-            ),
-          ],
-        )
     );
   }
 
@@ -70,20 +63,7 @@ class _FilesUploadDialogState extends State<FilesUploadDialog> {
       _overallProgressValue = 0.0;
       _infoText = '';
     });
-    showDialog(
+    InfoDialog.show(context, message, title: 'Upload fehlgeschlagen', copyable: true);
-      context: context,
-      builder: (BuildContext context) => AlertDialog(
-        title: const Text('Upload fehlgeschlagen'),
-        contentPadding: const EdgeInsets.all(10),
-        content: Text(message),
-        actions: [
-          TextButton(
-            onPressed: () => Navigator.of(context).pop(),
-            child: const Text('Schließen', textAlign: TextAlign.center),
-          ),
-        ],
-      ),
-    );
   }
 
   Future<void> uploadFiles({bool override = false}) async {

lib/view/pages/files/widgets/file_element.dart

@@ -11,6 +11,7 @@ import '../../../../utils/download_manager.dart';
 import '../../../../utils/file_clipboard.dart';
 import '../../../../widget/centered_leading.dart';
 import '../../../../widget/confirm_dialog.dart';
+import '../../../../widget/details_bottom_sheet.dart';
 import '../../../../widget/info_dialog.dart';
 import 'file_details_sheet.dart';
 
@@ -77,13 +78,7 @@ class _FileElementState extends State<FileElement> {
       DownloadManager.instance.clear(widget.file.path);
       _detachJob();
       setState(() {});
-      showDialog<void>(
+      InfoDialog.show(context, message, title: 'Download', copyable: true);
-        context: context,
-        builder: (context) => AlertDialog(
-          title: const Text('Download'),
-          content: Text(message),
-        ),
-      );
     } else if (status is DownloadCancelled) {
       DownloadManager.instance.clear(widget.file.path);
       _detachJob();
@@ -172,6 +167,7 @@ class _FileElementState extends State<FileElement> {
 
   Future<void> _rename() async {
     final controller = TextEditingController(text: widget.file.name);
+    try {
       final newName = await showDialog<String>(
         context: context,
         builder: (dialogCtx) => AlertDialog(
@@ -198,6 +194,9 @@ class _FileElementState extends State<FileElement> {
         final webdav = await WebdavApi.webdav;
         await webdav.move(PathUri.parse(widget.file.path), PathUri.parse(destination));
       }, errorTitle: 'Umbenennen fehlgeschlagen');
+    } finally {
+      controller.dispose();
+    }
   }
 
   void _putOnClipboard({required bool copy}) {
@@ -234,25 +233,14 @@ class _FileElementState extends State<FileElement> {
       widget.refetch();
     } on Object catch (e) {
       if (!mounted) return;
-      await showDialog<void>(
+      InfoDialog.show(context, e.toString(), title: errorTitle, copyable: true);
-        context: context,
-        builder: (dialogCtx) => AlertDialog(
-          title: Text(errorTitle),
-          content: Text(e.toString()),
-          actions: [TextButton(onPressed: () => Navigator.of(dialogCtx).pop(), child: const Text('OK'))],
-        ),
-      );
     }
   }
 
   void _showActionSheet() {
-    showModalBottomSheet<void>(
+    showDetailsBottomSheet(
-      context: context,
+      context,
-      showDragHandle: true,
+      children: (sheetCtx) => [
-      builder: (sheetCtx) => SafeArea(
-        child: Column(
-          mainAxisSize: MainAxisSize.min,
-          children: [
         ListTile(
           leading: const CenteredLeading(Icon(Icons.info_outline)),
           title: const Text('Info'),
@@ -294,8 +282,6 @@ class _FileElementState extends State<FileElement> {
           },
         ),
       ],
-        ),
-      ),
     );
   }
 

lib/view/pages/files/widgets/files_sort_actions.dart

@@ -2,9 +2,6 @@ import 'package:flutter/material.dart';
 
 import '../data/sort_options.dart';
 
-/// AppBar action buttons for sort direction (asc/desc) and sort field
-/// (name/date/size). Pure UI – owners pass current values + selection
-/// callbacks.
 class FilesSortActions extends StatelessWidget {
   final SortOption currentSort;
   final bool ascending;

lib/view/pages/holidays/holidays_view.dart

@@ -10,6 +10,8 @@ import '../../../state/app/modules/holidays/bloc/holidays_state.dart';
 import '../../../widget/animated_time.dart';
 import '../../../widget/centered_leading.dart';
 import '../../../widget/debug/debug_tile.dart';
+import '../../../widget/details_bottom_sheet.dart';
+import '../../../widget/info_dialog.dart';
 import '../../../widget/list_view_util.dart';
 import '../../../widget/string_extensions.dart';
 
@@ -21,18 +23,13 @@ class HolidaysView extends StatelessWidget {
     create: (context) => HolidaysBloc(),
     autoRebuild: true,
     child: (context, bloc, state) {
-      void showDisclaimer() {
+      void showDisclaimer() => InfoDialog.show(
-        showDialog(context: context, builder: (context) => AlertDialog(
+            context,
-          title: const Text('Richtigkeit und Bereitstellung der Daten'),
-          content: const Text(''
             'Sämtliche Datumsangaben sind ohne Gewähr.\n'
                 'Ich übernehme weder Verantwortung für die Richtigkeit der Daten noch hafte ich für wirtschaftliche Schäden die aus der Verwendung dieser Daten entstehen können.\n\n'
-              'Die Daten stammen von https://ferien-api.de/'),
+                'Die Daten stammen von https://ferien-api.de/',
-          actions: [
+            title: 'Richtigkeit und Bereitstellung der Daten',
-            TextButton(child: const Text('Okay'), onPressed: () => Navigator.of(context).pop()),
+          );
-          ],
-        ));
-      }
 
       return Scaffold(
         appBar: AppBar(
@@ -78,9 +75,16 @@ class HolidaysView extends StatelessWidget {
               leading: const CenteredLeading(Icon(Icons.calendar_month)),
               title: Text('$holidayType ${getHolidayYear(holiday.start, holiday.end)}'),
               subtitle: Text('${formatDate(holiday.start)} - ${formatDate(holiday.end)}'),
-              onTap: () => showDialog(context: context, builder: (context) => SimpleDialog(
+              onTap: () => showDetailsBottomSheet(
-                title: Text('$holidayType ${holiday.year} in Hessen'),
+                context,
-                children: [
+                header: Padding(
+                  padding: const EdgeInsets.fromLTRB(16, 4, 16, 12),
+                  child: Text(
+                    '$holidayType ${holiday.year} in Hessen',
+                    style: Theme.of(context).textTheme.titleLarge,
+                  ),
+                ),
+                children: (sheetCtx) => [
                   ListTile(
                     leading: const CenteredLeading(Icon(Icons.signpost_outlined)),
                     title: Text(holiday.name.capitalize()),
@@ -94,21 +98,20 @@ class HolidaysView extends StatelessWidget {
                     leading: const Icon(Icons.date_range_outlined),
                     title: Text('bis zum ${formatDate(holiday.end)}'),
                   ),
-                  Visibility(
+                  if (DateTime.parse(holiday.start).difference(DateTime.now()).isNegative)
-                    visible: !DateTime.parse(holiday.start).difference(DateTime.now()).isNegative,
+                    ListTile(
-                    replacement: ListTile(
                       leading: const CenteredLeading(Icon(Icons.content_paste_search_outlined)),
                       title: Text(Jiffy.parse(holiday.start).fromNow()),
-                    ),
+                    )
-                    child: ListTile(
+                  else
+                    ListTile(
                       leading: const CenteredLeading(Icon(Icons.timer_outlined)),
                       title: AnimatedTime(callback: () => DateTime.parse(holiday.start).difference(DateTime.now())),
                       subtitle: Text(Jiffy.parse(holiday.start).fromNow()),
                     ),
-                  ),
+                  DebugTile(sheetCtx).jsonData(holiday.toJson()),
-                  DebugTile(context).jsonData(holiday.toJson()),
                 ],
-              )),
+              ),
               trailing: const Icon(Icons.arrow_right),
             );
           }),

lib/view/pages/more/share/select_share_type_dialog.dart

@@ -5,26 +5,33 @@ import '../../../../widget/share_position_origin.dart';
 
 enum ShareTargetType { qr }
 
-class SelectShareTypeDialog extends StatelessWidget {
+/// Bottom sheet that lets the user pick how they want to share the app.
-  const SelectShareTypeDialog({super.key});
+/// Resolves with [ShareTargetType.qr] for the QR option, or `null` when the
-
+/// sheet is dismissed (link sharing fires immediately and resolves null).
-  @override
+Future<ShareTargetType?> showSelectShareTypeSheet(BuildContext context) {
-  Widget build(BuildContext context) => SimpleDialog(
+  return showModalBottomSheet<ShareTargetType>(
+    context: context,
+    isScrollControlled: true,
+    showDragHandle: true,
+    useSafeArea: true,
+    builder: (sheetCtx) => SafeArea(
+      child: Column(
+        mainAxisSize: MainAxisSize.min,
         children: [
           ListTile(
             leading: const Icon(Icons.qr_code_2_outlined),
             title: const Text('Per QR-Code'),
             trailing: const Icon(Icons.arrow_right),
-          onTap: () => Navigator.of(context).pop(ShareTargetType.qr),
+            onTap: () => Navigator.of(sheetCtx).pop(ShareTargetType.qr),
           ),
           ListTile(
             leading: const Icon(Icons.link_outlined),
             title: const Text('Per Link teilen'),
             trailing: const Icon(Icons.arrow_right),
             onTap: () {
-            Navigator.of(context).pop();
+              Navigator.of(sheetCtx).pop();
               SharePlus.instance.share(ShareParams(
-              sharePositionOrigin: SharePositionOrigin.get(context),
+                sharePositionOrigin: SharePositionOrigin.get(sheetCtx),
                 subject: 'App Teilen',
                 text: 'Hol dir die für das Marianum maßgeschneiderte App:'
                     '\n\nAndroid: https://play.google.com/store/apps/details?id=eu.mhsl.marianum.mobile.client '
@@ -32,7 +39,9 @@ class SelectShareTypeDialog extends StatelessWidget {
                     '\n\nViel Spaß!',
               ));
             },
-        )
+          ),
         ],
+      ),
+    ),
   );
 }

lib/view/pages/overhang.dart

@@ -42,10 +42,7 @@ class _OverhangState extends State<Overhang> {
             subtitle: const Text('Mit Freunden und deiner Klasse teilen'),
             trailing: const Icon(Icons.arrow_right),
             onTap: () async {
-              final result = await showDialog<ShareTargetType>(
+              final result = await showSelectShareTypeSheet(context);
-                context: context,
-                builder: (_) => const SelectShareTypeDialog(),
-              );
               if (!mounted || result != ShareTargetType.qr) return;
               if (context.mounted) AppRoutes.openQrShare(context);
             },

lib/view/pages/settings/sections/about_section.dart

@@ -7,6 +7,7 @@ import 'package:package_info_plus/package_info_plus.dart';
 import '../../../../state/app/modules/settings/bloc/settings_cubit.dart';
 import '../../../../widget/centered_leading.dart';
 import '../../../../widget/confirm_dialog.dart';
+import '../../../../widget/details_bottom_sheet.dart';
 import '../data/default_settings.dart';
 import '../widgets/privacy_info.dart';
 import 'dev_tools_section.dart';
@@ -69,10 +70,9 @@ class AboutSection extends StatelessWidget {
     );
   }
 
-  void _showPrivacyDialog(BuildContext context) => showDialog(
+  void _showPrivacyDialog(BuildContext context) => showDetailsBottomSheet(
-        context: context,
+        context,
-        builder: (context) => SimpleDialog(
+        children: (sheetCtx) => [
-          children: [
           ListTile(
             leading: const CenteredLeading(Icon(Icons.school_outlined)),
             title: const Text('Infos zum Marianum Fulda'),
@@ -82,7 +82,7 @@ class AboutSection extends StatelessWidget {
               providerText: 'Marianum',
               imprintUrl: 'https://www.marianum-fulda.de/impressum',
               privacyUrl: 'https://www.marianum-fulda.de/datenschutz',
-              ).showPopup(context),
+            ).showPopup(sheetCtx),
           ),
           ListTile(
             leading: const CenteredLeading(Icon(Icons.date_range_outlined)),
@@ -93,7 +93,7 @@ class AboutSection extends StatelessWidget {
               providerText: 'Untis',
               imprintUrl: 'https://www.untis.at/impressum',
               privacyUrl: 'https://www.untis.at/datenschutz-wu-apps',
-              ).showPopup(context),
+            ).showPopup(sheetCtx),
           ),
           ListTile(
             leading: const CenteredLeading(Icon(Icons.send_time_extension_outlined)),
@@ -104,10 +104,9 @@ class AboutSection extends StatelessWidget {
               providerText: 'mhsl',
               imprintUrl: 'https://mhsl.eu/id.html',
               privacyUrl: 'https://mhsl.eu/datenschutz.html',
-              ).showPopup(context),
+            ).showPopup(sheetCtx),
           ),
         ],
-        ),
       );
 
   void _toggleDeveloperMode(BuildContext context, SettingsCubit settings, bool? state) {

lib/view/pages/settings/sections/dev_tools_section.dart

@@ -11,6 +11,7 @@ import '../../../../widget/centered_leading.dart';
 import '../../../../widget/confirm_dialog.dart';
 import '../../../../widget/debug/cache_view.dart';
 import '../../../../widget/debug/json_viewer.dart';
+import '../../../../widget/details_bottom_sheet.dart';
 
 class DevToolsSection extends StatefulWidget {
   final SettingsCubit settings;
@@ -29,13 +30,15 @@ class _DevToolsSectionState extends State<DevToolsSection> {
           title: const Text('Performance overlays'),
           trailing: const Icon(Icons.arrow_right),
           onTap: () {
-            showDialog(
+            showDetailsBottomSheet(
-              context: context,
+              context,
-              builder: (dialogCtx) => BlocBuilder<SettingsCubit, model.Settings>(
+              children: (sheetCtx) => [
+                BlocBuilder<SettingsCubit, model.Settings>(
                   bloc: widget.settings,
                   builder: (_, _) {
                     final dev = widget.settings.val().devToolsSettings;
-                  return SimpleDialog(
+                    return Column(
+                      mainAxisSize: MainAxisSize.min,
                       children: [
                         ListTile(
                           leading: const Icon(Icons.auto_graph_outlined),
@@ -65,6 +68,7 @@ class _DevToolsSectionState extends State<DevToolsSection> {
                     );
                   },
                 ),
+              ],
             );
           },
         ),
@@ -122,9 +126,6 @@ class _DevToolsSectionState extends State<DevToolsSection> {
           leading: const CenteredLeading(Icon(Icons.data_object)),
           title: const Text('BLOC-storage state cache'),
           subtitle: const Text('Lange tippen um zu löschen'),
-          onTap: () {
-            // Navigator.push(context, MaterialPageRoute(builder: (context) => const CacheView()));
-          },
           onLongPress: () {
             ConfirmDialog(
               title: 'BLOC-Cache löschen',

lib/view/pages/settings/widgets/privacy_info.dart

@@ -2,6 +2,7 @@ import 'package:flutter/material.dart';
 
 import '../../../../widget/centered_leading.dart';
 import '../../../../widget/confirm_dialog.dart';
+import '../../../../widget/details_bottom_sheet.dart';
 
 class PrivacyInfo {
   String providerText;
@@ -11,22 +12,29 @@ class PrivacyInfo {
   PrivacyInfo({required this.providerText, required this.imprintUrl, required this.privacyUrl});
 
   void showPopup(BuildContext context) {
-    showDialog(context: context, builder: (context) => SimpleDialog(
+    showDetailsBottomSheet(
-        title: Text('Betreiberinformation | $providerText'),
+      context,
-        children: [
+      header: Padding(
+        padding: const EdgeInsets.fromLTRB(16, 4, 16, 12),
+        child: Text(
+          'Betreiberinformation | $providerText',
+          style: Theme.of(context).textTheme.titleLarge,
+        ),
+      ),
+      children: (sheetCtx) => [
         ListTile(
           leading: const CenteredLeading(Icon(Icons.person_pin_outlined)),
           title: const Text('Impressum'),
           subtitle: Text(imprintUrl),
-            onTap: () => ConfirmDialog.openBrowser(context, imprintUrl),
+          onTap: () => ConfirmDialog.openBrowser(sheetCtx, imprintUrl),
         ),
         ListTile(
           leading: const CenteredLeading(Icon(Icons.privacy_tip_outlined)),
           title: const Text('Datenschutzerklärung'),
           subtitle: Text(privacyUrl),
-            onTap: () => ConfirmDialog.openBrowser(context, privacyUrl),
+          onTap: () => ConfirmDialog.openBrowser(sheetCtx, privacyUrl),
         ),
       ],
-      ));
+    );
   }
 }

lib/view/pages/talk/chat_list.dart

@@ -12,6 +12,7 @@ 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';
 import '../../../widget/confirm_dialog.dart';
+import '../../../widget/info_dialog.dart';
 import '../../../widget/placeholder_view.dart';
 import 'join_chat.dart';
 import 'search_chat.dart';
@@ -98,11 +99,9 @@ class _ChatListViewState extends State<_ChatListView> {
               NotifyUpdater.enableAfterDisclaimer(_settings).asDialog(context);
               break;
             case AuthorizationStatus.denied:
-              showDialog(
+              InfoDialog.show(
-                context: context,
+                context,
-                builder: (_) => const AlertDialog(
+                'Du kannst die Benachrichtigungen später jederzeit in den App-Einstellungen aktivieren.',
-                  content: Text('Du kannst die Benachrichtigungen später jederzeit in den App-Einstellungen aktivieren.'),
-                ),
               );
               break;
             default:

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

@@ -40,9 +40,8 @@ class BubbleStyle {
   final double borderRadius;
 }
 
-/// Lightweight chat bubble. Replaces the abandoned `bubble` package: renders a
+/// The "nip" is faked by flattening one corner so the bubble anchors to
-/// rounded container with optional shadow / border. The nip is conveyed by
+/// the speaker side.
-/// flattening one corner so the bubble visually anchors to the speaker side.
 class Bubble extends StatelessWidget {
   const Bubble({required this.child, required this.style, super.key});
 

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

@@ -246,9 +246,6 @@ class _ChatBubbleState extends State<ChatBubble> with SingleTickerProviderStateM
   }
 }
 
-/// Stack inside the bubble: actor name (top-left, optional), message body
-/// (centre), timestamp + read marker (bottom-right, optional), and a
-/// download progress bar overlaid at the bottom while a job is running.
 class _BubbleContent extends StatelessWidget {
   final Text actorText;
   final Text timeText;

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

@@ -14,13 +14,14 @@ import '../../../../utils/clipboard_helper.dart';
 import '../../../../widget/app_progress_indicator.dart';
 import '../../../../widget/async_action_button.dart';
 import '../../../../widget/debug/debug_tile.dart';
+import '../../../../widget/details_bottom_sheet.dart';
 
 const _commonReactions = <String>['👍', '👎', '😆', '❤️', '👀'];
 
 /// Long-press / double-tap options dialog for a single chat message bubble.
 /// The hosting [ChatBubble] keeps responsibility for rendering the bubble;
 /// this file owns the modal interactions (react, reply, copy, delete, ...).
-Future<void> showChatMessageOptionsDialog(
+void showChatMessageOptionsDialog(
   BuildContext context, {
   required GetRoomResponseObject chatData,
   required GetChatResponseObject bubbleData,
@@ -34,24 +35,23 @@ Future<void> showChatMessageOptionsDialog(
           .add(const Duration(hours: 6))
           .isAfter(DateTime.now());
 
-  return showDialog(
+  showDetailsBottomSheet(
-    context: context,
+    context,
-    builder: (dialogCtx) => SimpleDialog(
+    children: (sheetCtx) => [
-      children: [
       if (canReact)
         _ReactionsRow(
           chatToken: chatData.token,
           messageId: bubbleData.id,
           onRefetch: onRefetch,
-            dialogContext: dialogCtx,
+          sheetContext: sheetCtx,
         ),
       if (bubbleData.isReplyable)
         ListTile(
           leading: const Icon(Icons.reply_outlined),
           title: const Text('Antworten'),
           onTap: () {
-              dialogCtx.read<ChatBloc>().setReferenceMessageId(bubbleData.id);
+            sheetCtx.read<ChatBloc>().setReferenceMessageId(bubbleData.id);
-              Navigator.of(dialogCtx).pop();
+            Navigator.of(sheetCtx).pop();
           },
         ),
       if (canReact)
@@ -59,7 +59,7 @@ Future<void> showChatMessageOptionsDialog(
           leading: const Icon(Icons.emoji_emotions_outlined),
           title: const Text('Reaktionen'),
           onTap: () {
-              Navigator.of(dialogCtx).pop();
+            Navigator.of(sheetCtx).pop();
             if (!parentContext.mounted) return;
             AppRoutes.openMessageReactions(parentContext, chatData.token, bubbleData.id);
           },
@@ -70,14 +70,14 @@ Future<void> showChatMessageOptionsDialog(
           title: const Text('Nachricht kopieren'),
           onTap: () {
             copyToClipboard(parentContext, bubbleData.message);
-              Navigator.of(dialogCtx).pop();
+            Navigator.of(sheetCtx).pop();
           },
         ),
       if (!kReleaseMode && !isSender && chatData.type != GetRoomResponseObjectConversationType.oneToOne)
         ListTile(
           leading: const Icon(Icons.sms_outlined),
           title: Text("Private Nachricht an '${bubbleData.actorDisplayName}'"),
-            onTap: () => Navigator.of(dialogCtx).pop(),
+          onTap: () => Navigator.of(sheetCtx).pop(),
         ),
       if (canDelete)
         AsyncListTile(
@@ -85,12 +85,11 @@ Future<void> showChatMessageOptionsDialog(
           title: const Text('Nachricht löschen'),
           onPressed: () async {
             await DeleteMessage(chatData.token, bubbleData.id).run();
-              if (dialogCtx.mounted) dialogCtx.read<ChatBloc>().refresh();
+            if (sheetCtx.mounted) sheetCtx.read<ChatBloc>().refresh();
           },
         ),
-        DebugTile(dialogCtx).jsonData(bubbleData.toJson()),
+      DebugTile(sheetCtx).jsonData(bubbleData.toJson()),
     ],
-    ),
   );
 }
 
@@ -98,13 +97,13 @@ class _ReactionsRow extends StatefulWidget {
   final String chatToken;
   final int messageId;
   final void Function({bool renew}) onRefetch;
-  final BuildContext dialogContext;
+  final BuildContext sheetContext;
 
   const _ReactionsRow({
     required this.chatToken,
     required this.messageId,
     required this.onRefetch,
-    required this.dialogContext,
+    required this.sheetContext,
   });
 
   @override
@@ -131,7 +130,7 @@ class _ReactionsRowState extends State<_ReactionsRow> {
     if (!mounted) return;
     if (ok) {
       widget.onRefetch(renew: true);
-      if (widget.dialogContext.mounted) Navigator.of(widget.dialogContext).pop();
+      if (widget.sheetContext.mounted) Navigator.of(widget.sheetContext).pop();
     }
   }
 

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

@@ -15,6 +15,7 @@ import '../../../../state/app/modules/chat_list/bloc/chat_list_bloc.dart';
 import '../../../../widget/async_action_button.dart';
 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';
@@ -124,8 +125,9 @@ class _ChatTileState extends State<ChatTile> {
       },
       onLongPress: () {
         if (widget.disableContextActions) return;
-        showDialog(context: context, builder: (dialogCtx) => SimpleDialog(
+        showDetailsBottomSheet(
-          children: [
+          context,
+          children: (sheetCtx) => [
             if (widget.data.unreadMessages > 0)
               AsyncListTile(
                 leading: const Icon(Icons.mark_chat_read_outlined),
@@ -163,7 +165,7 @@ class _ChatTileState extends State<ChatTile> {
               leading: const Icon(Icons.delete_outline),
               title: const Text('Konversation verlassen'),
               onTap: () {
-                Navigator.of(dialogCtx).pop();
+                Navigator.of(sheetCtx).pop();
                 ConfirmDialog(
                   title: 'Chat verlassen',
                   content: 'Du benötigst ggf. eine Einladung um erneut beizutreten.',
@@ -175,9 +177,9 @@ class _ChatTileState extends State<ChatTile> {
                 ).asDialog(context);
               },
             ),
-            DebugTile(dialogCtx).jsonData(widget.data.toJson()),
+            DebugTile(sheetCtx).jsonData(widget.data.toJson()),
           ],
-        ));
+        );
       },
     );
   }

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

@@ -29,7 +29,6 @@ class _PollOptionsListState extends State<PollOptionsList> {
         final portion = numVoters == 0 ? 0.0 : (votes / numVoters);
 
         return ListTile(
-          // enabled: false,
           isThreeLine: portionsVisible,
           dense: true,
           title: Text(

lib/view/pages/timetable/data/calendar_layout.dart

@@ -3,14 +3,22 @@ const double kCalendarEndHour = 17.25;
 const Duration kCalendarTimeInterval = Duration(minutes: 30);
 const double kCalendarViewHeaderHeight = 60;
 
-/// Minimum pixels per hour. Below this, the grid scrolls vertically rather
+/// Below this, the grid scrolls vertically rather than compressing further.
-/// than compressing further.
 const double kCalendarMinPxPerHour = 56;
 
-/// Minimum height of a lesson block in the period-based layout. The grid
+/// The grid scrolls vertically once lessons would otherwise be smaller.
-/// scrolls vertically once lessons would otherwise be smaller than this.
 const double kLessonBlockMinHeight = 50;
 
-/// Fixed height of a break block in the period-based layout. Independent of
+/// Fixed (independent of actual break duration); breaks render as a compact
-/// the actual break duration; breaks are rendered as a compact indicator.
+/// indicator.
 const double kBreakBlockHeight = 28;
+
+const int kOutsideChipsMaxVisible = 2;
+const double kOutsideChipHeight = 22;
+const double kOutsideChipSpacing = 3;
+const double kOutsideStripVerticalPadding = 3;
+
+const double kAppointmentTitleFontSize = 15;
+const double kAppointmentTitleMinFontSize = 11;
+const double kAppointmentBodyFontSize = 10;
+const double kAppointmentBodyLineHeight = 1.15;

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

@@ -2,14 +2,11 @@ import 'package:flutter/material.dart';
 import 'package:syncfusion_flutter_calendar/calendar.dart';
 
 import '../data/arbitrary_appointment.dart';
+import '../data/calendar_layout.dart';
 import 'cross_painter.dart';
 
 class AppointmentTile extends StatelessWidget {
   static const _radius = BorderRadius.all(Radius.circular(7));
-  static const _titleFontSize = 15.0;
-  static const _titleMinFontSize = 11.0;
-  static const _bodyFontSize = 10.0;
-  static const _bodyLineHeight = 1.15;
 
   final Appointment appointment;
   final bool crossedOut;
@@ -42,8 +39,8 @@ class AppointmentTile extends StatelessWidget {
                 children: [
                   _AdaptiveTitle(
                     text: appointment.subject,
-                    fontSize: _titleFontSize,
+                    fontSize: kAppointmentTitleFontSize,
-                    minFontSize: _titleMinFontSize,
+                    minFontSize: kAppointmentTitleMinFontSize,
                     fontWeight: FontWeight.w500,
                   ),
                   if (isCustom) ...[
@@ -53,8 +50,8 @@ class AppointmentTile extends StatelessWidget {
                           padding: const EdgeInsets.only(top: 1),
                           child: _WrappingBody(
                             text: description,
-                            fontSize: _bodyFontSize,
+                            fontSize: kAppointmentBodyFontSize,
-                            lineHeight: _bodyLineHeight,
+                            lineHeight: kAppointmentBodyLineHeight,
                           ),
                         ),
                       ),
@@ -63,7 +60,7 @@ class AppointmentTile extends StatelessWidget {
                         .split('\n')
                         .where((p) => p.isNotEmpty)
                         .take(2))
-                      _ScaledLine(text: line, fontSize: _bodyFontSize),
+                      _ScaledLine(text: line, fontSize: kAppointmentBodyFontSize),
                   ],
                 ],
               ),

lib/view/pages/timetable/widgets/calendar/outside_chips.dart

@@ -1,11 +1,6 @@
 part of '../custom_workweek_calendar.dart';
 
 class _OutsideHoursStrip extends StatelessWidget {
-  static const int _maxVisibleChips = 2;
-  static const double _chipHeight = 22;
-  static const double _chipSpacing = 3;
-  static const double _verticalPadding = 3;
-
   final DateTime weekStart;
   final List<Appointment> appointments;
   final double rulerWidth;
@@ -28,17 +23,17 @@ class _OutsideHoursStrip extends StatelessWidget {
 
     final theme = Theme.of(context);
     final maxChipsPerDay = outside
-        .map((day) => day.length > _maxVisibleChips ? _maxVisibleChips : day.length)
+        .map((day) => day.length > kOutsideChipsMaxVisible ? kOutsideChipsMaxVisible : day.length)
         .fold<int>(0, (m, c) => c > m ? c : m);
-    final stripHeight = _verticalPadding * 2 +
+    final stripHeight = kOutsideStripVerticalPadding * 2 +
-        maxChipsPerDay * _chipHeight +
+        maxChipsPerDay * kOutsideChipHeight +
-        (maxChipsPerDay > 1 ? (maxChipsPerDay - 1) * _chipSpacing : 0);
+        (maxChipsPerDay > 1 ? (maxChipsPerDay - 1) * kOutsideChipSpacing : 0);
 
     return Container(
       color: theme.colorScheme.surfaceContainerLowest,
-      padding: const EdgeInsets.symmetric(vertical: _verticalPadding),
+      padding: const EdgeInsets.symmetric(vertical: kOutsideStripVerticalPadding),
       child: SizedBox(
-        height: stripHeight - _verticalPadding * 2,
+        height: stripHeight - kOutsideStripVerticalPadding * 2,
         child: Row(
           crossAxisAlignment: CrossAxisAlignment.start,
           children: [
@@ -47,9 +42,6 @@ class _OutsideHoursStrip extends StatelessWidget {
               Expanded(
                 child: _OutsideDayColumn(
                   appointments: outside[d],
-                  maxVisible: _maxVisibleChips,
-                  chipHeight: _chipHeight,
-                  chipSpacing: _chipSpacing,
                   onAppointmentTap: onAppointmentTap,
                   isCrossedOut: isCrossedOut,
                 ),
@@ -63,17 +55,11 @@ class _OutsideHoursStrip extends StatelessWidget {
 
 class _OutsideDayColumn extends StatelessWidget {
   final List<Appointment> appointments;
-  final int maxVisible;
-  final double chipHeight;
-  final double chipSpacing;
   final void Function(Appointment) onAppointmentTap;
   final bool Function(Appointment) isCrossedOut;
 
   const _OutsideDayColumn({
     required this.appointments,
-    required this.maxVisible,
-    required this.chipHeight,
-    required this.chipSpacing,
     required this.onAppointmentTap,
     required this.isCrossedOut,
   });
@@ -132,11 +118,12 @@ class _OutsideDayColumn extends StatelessWidget {
         if (!aLike && bLike) return 1;
         return a.startTime.compareTo(b.startTime);
       });
-    final visible = sorted.length <= maxVisible
+    final visible = sorted.length <= kOutsideChipsMaxVisible
         ? sorted
-        : sorted.take(maxVisible - 1).toList();
+        : sorted.take(kOutsideChipsMaxVisible - 1).toList();
-    final overflow =
+    final overflow = sorted.length <= kOutsideChipsMaxVisible
-        sorted.length <= maxVisible ? const <Appointment>[] : sorted.skip(maxVisible - 1).toList();
+        ? const <Appointment>[]
+        : sorted.skip(kOutsideChipsMaxVisible - 1).toList();
 
     return Padding(
       padding: const EdgeInsets.symmetric(horizontal: 2),
@@ -145,9 +132,9 @@ class _OutsideDayColumn extends StatelessWidget {
         crossAxisAlignment: CrossAxisAlignment.stretch,
         children: [
           for (var i = 0; i < visible.length; i++) ...[
-            if (i > 0) SizedBox(height: chipSpacing),
+            if (i > 0) const SizedBox(height: kOutsideChipSpacing),
             SizedBox(
-              height: chipHeight,
+              height: kOutsideChipHeight,
               child: _OutsideChip(
                 appointment: visible[i],
                 onTap: () => onAppointmentTap(visible[i]),
@@ -155,9 +142,9 @@ class _OutsideDayColumn extends StatelessWidget {
             ),
           ],
           if (overflow.isNotEmpty) ...[
-            SizedBox(height: chipSpacing),
+            const SizedBox(height: kOutsideChipSpacing),
             SizedBox(
-              height: chipHeight,
+              height: kOutsideChipHeight,
               child: _OutsideOverflowChip(
                 count: overflow.length,
                 onTap: () => _showOverflow(context, overflow),

lib/view/pages/timetable/widgets/calendar/week_grid.dart

@@ -429,8 +429,7 @@ class _OverflowTile extends StatelessWidget {
       padding: const EdgeInsets.all(1),
       child: Stack(
         children: [
-          // Card peeking out at the bottom — visual hint that more cards lie
+          // Stacked-cards effect: a darker layer peeks out below the front card.
-          // underneath the visible one.
           Positioned(
             top: 4,
             left: 2,
@@ -443,7 +442,6 @@ class _OverflowTile extends StatelessWidget {
               ),
             ),
           ),
-          // Front card with the "+N" indicator.
           Positioned(
             top: 0,
             left: 0,

lib/widget/async_actions/async_text_button.dart

@@ -40,10 +40,9 @@ class AsyncTextButton extends StatelessWidget {
                   ],
                 )
               : child;
-          return _InlineErrorWrapper(
+          final button = TextButton(onPressed: handler, child: content);
-            controller: controller,
+          if (!showInlineError) return button;
-            child: TextButton(onPressed: handler, child: content),
+          return _InlineErrorWrapper(controller: controller, child: button);
-          );
         },
       );
 }

lib/widget/file_viewer.dart

@@ -81,7 +81,7 @@ class _DeferredPdfViewerState extends State<_DeferredPdfViewer> {
 }
 
 class _FileViewerState extends State<FileViewer> {
-  PhotoViewController photoViewController = PhotoViewController();
+  final PhotoViewController photoViewController = PhotoViewController();
 
   late SettingsCubit settings = context.read<SettingsCubit>();
   late bool openExternal;
@@ -92,6 +92,12 @@ class _FileViewerState extends State<FileViewer> {
     super.initState();
   }
 
+  @override
+  void dispose() {
+    photoViewController.dispose();
+    super.dispose();
+  }
+
   @override
   Widget build(BuildContext context) {
     AppBar appbar({List<Widget> actions = const []}) => AppBar(
@@ -196,9 +202,7 @@ class _FileViewerState extends State<FileViewer> {
           if (!context.mounted) return;
           Navigator.of(context).pop();
           if (result.type != ResultType.done) {
-            showDialog(context: context, builder: (context) => AlertDialog(
+            InfoDialog.show(context, result.message);
-                content: Text(result.message),
-              ));
           }
         });
 

test/api/errors/error_mapper_test.dart

@@ -1,6 +1,7 @@
 import 'dart:async';
 import 'dart:io';
 
+import 'package:dio/dio.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:http/http.dart' as http;
 import 'package:marianum_mobile/api/api_error.dart';
@@ -36,8 +37,9 @@ void main() {
     });
 
     test('HandshakeException maps to a TLS-specific message', () {
-      expect(errorToUserMessage(const HandshakeException('bad cert')),
+      final message = errorToUserMessage(const HandshakeException('bad cert'));
-          'Sichere Verbindung konnte nicht hergestellt werden.');
+      expect(message, contains('sichere Verbindung'));
+      expect(message, contains('Geräte-Uhrzeit'));
     });
 
     test('FormatException maps to ParseException message', () {
@@ -63,6 +65,34 @@ void main() {
     test('custom fallback overrides the default', () {
       expect(errorToUserMessage(null, fallback: 'meins'), 'meins');
     });
+
+    test('DioException connectionTimeout maps to timeout NetworkException', () {
+      final ex = DioException(
+        requestOptions: RequestOptions(path: '/x'),
+        type: DioExceptionType.connectionTimeout,
+      );
+      expect(errorToUserMessage(ex), NetworkException.timeout().userMessage);
+    });
+
+    test('DioException connectionError maps to NetworkException', () {
+      final ex = DioException(
+        requestOptions: RequestOptions(path: '/x'),
+        type: DioExceptionType.connectionError,
+      );
+      expect(errorToUserMessage(ex), const NetworkException().userMessage);
+    });
+
+    test('DioException badResponse maps to a server status message', () {
+      final ex = DioException(
+        requestOptions: RequestOptions(path: '/x'),
+        type: DioExceptionType.badResponse,
+        response: Response(
+          requestOptions: RequestOptions(path: '/x'),
+          statusCode: 503,
+        ),
+      );
+      expect(errorToUserMessage(ex), contains('503'));
+    });
   });
 
   group('errorToTechnicalDetails', () {