added clear message for denied camera or gallery access

lib/api/errors/permission_exception.dart

@@ -0,0 +1,41 @@
+import 'package:flutter/services.dart';
+
+import 'app_exception.dart';
+
+/// The user denied a system permission the action needs (camera, photos).
+/// Retrying won't help until the permission is granted in the system settings.
+class PermissionException extends AppException {
+  const PermissionException({
+    required super.userMessage,
+    super.technicalDetails,
+  }) : super(allowRetry: false);
+
+  factory PermissionException.camera({String? technicalDetails}) =>
+      PermissionException(
+        userMessage:
+            'Kein Zugriff auf die Kamera. Bitte erlaube der App den '
+            'Kamerazugriff in den Einstellungen deines Geräts.',
+        technicalDetails: technicalDetails,
+      );
+
+  factory PermissionException.photos({String? technicalDetails}) =>
+      PermissionException(
+        userMessage:
+            'Kein Zugriff auf deine Fotos. Bitte erlaube der App den '
+            'Fotozugriff in den Einstellungen deines Geräts.',
+        technicalDetails: technicalDetails,
+      );
+
+  /// Maps the `*_access_denied` codes thrown by `image_picker`; `null` for any
+  /// other platform error.
+  static PermissionException? fromPlatform(PlatformException error) =>
+      switch (error.code) {
+        'camera_access_denied' => PermissionException.camera(
+          technicalDetails: error.message,
+        ),
+        'photo_access_denied' => PermissionException.photos(
+          technicalDetails: error.message,
+        ),
+        _ => null,
+      };
+}

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

@@ -38,7 +38,7 @@ void showAddFileSheet(
         leading: const Icon(Icons.add_a_photo_outlined),
         title: const Text('Aus Galerie hochladen'),
         onTap: () {
-          FilePick.multipleGalleryPick().then((value) {
+          FilePick.multipleGalleryPick(context).then((value) {
             if (value != null) onPickedFiles(value.map((e) => e.path).toList());
           });
           Navigator.of(sheetCtx).pop();
@@ -48,7 +48,7 @@ void showAddFileSheet(
         leading: const Icon(Icons.camera_alt_outlined),
         title: const Text('Foto aufnehmen'),
         onTap: () {
-          FilePick.cameraPick().then((image) {
+          FilePick.cameraPick(context).then((image) {
             if (image != null) onPickedFiles([image.path]);
           });
           Navigator.of(sheetCtx).pop();

lib/view/pages/more/feedback/feedback_dialog.dart

@@ -43,7 +43,7 @@ class _FeedbackDialogState extends State<FeedbackDialog> {
   }
 
   Future<void> _pickImage() async {
-    final picked = await FilePick.singleGalleryPick();
+    final picked = await FilePick.singleGalleryPick(context);
     if (picked == null) return;
     final data = await picked.readAsBytes();
     if (!mounted) return;

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

@@ -164,7 +164,7 @@ class _ChatTextfieldState extends State<ChatTextfield> {
           leading: const Icon(Icons.image),
           title: const Text('Aus Galerie auswählen'),
           onTap: () {
-            FilePick.multipleGalleryPick().then((value) {
+            FilePick.multipleGalleryPick(context).then((value) {
               if (value != null) {
                 mediaUpload(value.map((e) => e.path).toList());
               }
@@ -176,7 +176,7 @@ class _ChatTextfieldState extends State<ChatTextfield> {
           leading: const Icon(Icons.camera_alt_outlined),
           title: const Text('Foto aufnehmen'),
           onTap: () {
-            FilePick.cameraPick().then((image) {
+            FilePick.cameraPick(context).then((image) {
               if (image != null) mediaUpload([image.path]);
             });
             Navigator.of(sheetCtx).pop();

lib/widget/avatar_actions_sheet.dart

@@ -42,7 +42,7 @@ Future<AvatarSheetResult?> showAvatarActionsSheet(
         onTap: () async {
           final bytes = await _pickAndCrop(
             sheetContext,
-            FilePick.singleGalleryPick,
+            () => FilePick.singleGalleryPick(sheetContext),
           );
           if (bytes == null || !sheetContext.mounted) return;
           result = AvatarUploadResult(bytes);
@@ -53,7 +53,10 @@ Future<AvatarSheetResult?> showAvatarActionsSheet(
         leading: const Icon(Icons.photo_camera_outlined),
         title: const Text('Foto aufnehmen'),
         onTap: () async {
-          final bytes = await _pickAndCrop(sheetContext, FilePick.cameraPick);
+          final bytes = await _pickAndCrop(
+            sheetContext,
+            () => FilePick.cameraPick(sheetContext),
+          );
           if (bytes == null || !sheetContext.mounted) return;
           result = AvatarUploadResult(bytes);
           Navigator.of(sheetContext).pop();

lib/widget/chat_background_picker_sheet.dart

@@ -21,7 +21,9 @@ Future<Uint8List?> showChatBackgroundPickerSheet(BuildContext context) async {
         leading: const Icon(Icons.photo_library_outlined),
         title: const Text('Aus Galerie wählen'),
         onTap: () async {
-          final bytes = await _pickRaw(FilePick.singleGalleryPick);
+          final bytes = await _pickRaw(
+            () => FilePick.singleGalleryPick(sheetContext),
+          );
           if (bytes == null || !sheetContext.mounted) return;
           result = bytes;
           Navigator.of(sheetContext).pop();
@@ -31,7 +33,7 @@ Future<Uint8List?> showChatBackgroundPickerSheet(BuildContext context) async {
         leading: const Icon(Icons.photo_camera_outlined),
         title: const Text('Foto aufnehmen'),
         onTap: () async {
-          final bytes = await _pickRaw(FilePick.cameraPick);
+          final bytes = await _pickRaw(() => FilePick.cameraPick(sheetContext));
           if (bytes == null || !sheetContext.mounted) return;
           result = bytes;
           Navigator.of(sheetContext).pop();

lib/widget/file_pick.dart

@@ -1,22 +1,77 @@
+import 'package:app_settings/app_settings.dart';
 import 'package:file_picker/file_picker.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
 import 'package:image_picker/image_picker.dart';
 
+import '../api/errors/error_mapper.dart';
+import '../api/errors/permission_exception.dart';
+import 'confirm_dialog.dart';
+import 'info_dialog.dart';
+
+/// Thin wrapper around the platform pickers. Every method resolves to `null`
+/// when the user cancels **or** when picking failed; failures are reported to
+/// the user right here (permission denial with a shortcut to the system
+/// settings, everything else as a plain error dialog) so call sites can treat
+/// the result like a cancel.
 class FilePick {
   static final _picker = ImagePicker();
 
-  static Future<List<XFile>?> multipleGalleryPick() async {
+  static Future<List<XFile>?> multipleGalleryPick(BuildContext context) =>
+      _guarded(context, () async {
         final pickedImages = await _picker.pickMultiImage();
         return pickedImages.isNotEmpty ? pickedImages : null;
-  }
+      });
 
-  static Future<XFile?> singleGalleryPick() =>
+  static Future<XFile?> singleGalleryPick(BuildContext context) =>
-      _picker.pickImage(source: ImageSource.gallery);
+      _guarded(context, () => _picker.pickImage(source: ImageSource.gallery));
 
-  static Future<XFile?> cameraPick() =>
+  static Future<XFile?> cameraPick(BuildContext context) =>
-      _picker.pickImage(source: ImageSource.camera);
+      _guarded(context, () => _picker.pickImage(source: ImageSource.camera));
 
   static Future<List<String>?> documentPick() async {
     final result = await FilePicker.pickFiles(allowMultiple: true);
     return result?.files.map((e) => e.path).nonNulls.toList();
   }
+
+  static Future<T?> _guarded<T>(
+    BuildContext context,
+    Future<T?> Function() pick,
+  ) async {
+    try {
+      return await pick();
+    } on PlatformException catch (e) {
+      final denied = PermissionException.fromPlatform(e);
+      if (!context.mounted) return null;
+      if (denied != null) {
+        _showPermissionDialog(context, denied);
+      } else {
+        _showErrorDialog(context, e);
+      }
+      return null;
+    } catch (e) {
+      if (context.mounted) _showErrorDialog(context, e);
+      return null;
+    }
+  }
+
+  static void _showPermissionDialog(
+    BuildContext context,
+    PermissionException denied,
+  ) => ConfirmDialog(
+    icon: Icons.block_outlined,
+    title: 'Zugriff verweigert',
+    content: denied.userMessage,
+    confirmButton: 'Einstellungen öffnen',
+    onConfirm: AppSettings.openAppSettings,
+  ).asDialog(context);
+
+  static void _showErrorDialog(BuildContext context, Object error) {
+    final message = errorToUserMessage(error);
+    final details = errorToTechnicalDetails(error);
+    final body = details != null && details != message
+        ? '$message\n\n$details'
+        : message;
+    InfoDialog.show(context, body, copyable: true, title: 'Fehler');
+  }
 }

test/api/errors/error_mapper_test.dart

@@ -2,6 +2,7 @@ import 'dart:async';
 import 'dart:io';
 
 import 'package:dio/dio.dart';
+import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:http/http.dart' as http;
 import 'package:marianum_mobile/api/api_error.dart';
@@ -10,6 +11,7 @@ import 'package:marianum_mobile/api/errors/error_mapper.dart';
 import 'package:marianum_mobile/api/errors/network_exception.dart';
 import 'package:marianum_mobile/api/errors/not_found_exception.dart';
 import 'package:marianum_mobile/api/errors/parse_exception.dart';
+import 'package:marianum_mobile/api/errors/permission_exception.dart';
 import 'package:nextcloud/nextcloud.dart';
 
 void main() {
@@ -142,10 +144,7 @@ void main() {
 
     test('401 maps to the unauthorized AuthException', () {
       const ex = DynamiteApiException(401, {}, '');
-      expect(
+      expect(errorToUserMessage(ex), AuthException.unauthorized().userMessage);
-        errorToUserMessage(ex),
-        AuthException.unauthorized().userMessage,
-      );
       expect(errorAllowsRetry(ex), isFalse);
     });
 
@@ -205,4 +204,29 @@ void main() {
       expect(errorAllowsRetry(StateError('x')), isTrue);
     });
   });
+
+  group('PermissionException.fromPlatform', () {
+    test('camera_access_denied maps to the camera message', () {
+      final mapped = PermissionException.fromPlatform(
+        PlatformException(code: 'camera_access_denied', message: 'denied'),
+      );
+      expect(mapped?.userMessage, contains('Kamera'));
+      expect(mapped?.technicalDetails, 'denied');
+      expect(errorAllowsRetry(mapped), isFalse);
+    });
+
+    test('photo_access_denied maps to the photos message', () {
+      final mapped = PermissionException.fromPlatform(
+        PlatformException(code: 'photo_access_denied'),
+      );
+      expect(mapped?.userMessage, contains('Fotos'));
+    });
+
+    test('unrelated platform codes are not mapped', () {
+      expect(
+        PermissionException.fromPlatform(PlatformException(code: 'other')),
+        isNull,
+      );
+    });
+  });
 }