savedPreferences for themes

docs/prompt.md

@@ -44,3 +44,8 @@ Folgende Dateien wurden in diesem Prompt verändert:
 - Use the first three letters of the username as the avatar for the profile and remove the team name input in the settings.<br><br>
 Folgende Dateien wurden in diesem Prompt verändert:
     - frontend_splatournament_manager/lib/widgets/profile_widget.dart
+
+- Save the theme preferences so they persist across restarts.<br><br>
+Folgende Dateien wurden in diesem Prompt verändert:
+    - frontend_splatournament_manager/pubspec.yaml
+    - frontend_splatournament_manager/lib/providers/theme_provider.dart

frontend_splatournament_manager/lib/providers/theme_provider.dart

@@ -1,12 +1,51 @@
 import 'package:flutter/material.dart';
+import 'package:shared_preferences/shared_preferences.dart';
 
 class ThemeProvider extends ChangeNotifier {
+  static const String _themeKey = 'theme_mode';
   ThemeMode _themeMode = ThemeMode.system;
 
   ThemeMode get theme => _themeMode;
 
-  void setTheme(ThemeMode mode) {
-    _themeMode = mode;
+  ThemeProvider() {
+    _loadTheme();
+  }
+
+  Future<void> _loadTheme() async {
+    final prefs = await SharedPreferences.getInstance();
+    final themeName = prefs.getString(_themeKey) ?? 'system';
+    _themeMode = _themeFromString(themeName);
     notifyListeners();
   }
+
+  Future<void> setTheme(ThemeMode mode) async {
+    _themeMode = mode;
+    notifyListeners();
+    
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.setString(_themeKey, _themeToString(mode));
+  }
+
+  String _themeToString(ThemeMode mode) {
+    switch (mode) {
+      case ThemeMode.light:
+        return 'light';
+      case ThemeMode.dark:
+        return 'dark';
+      case ThemeMode.system:
+        return 'system';
+    }
+  }
+
+  ThemeMode _themeFromString(String theme) {
+    switch (theme) {
+      case 'light':
+        return ThemeMode.light;
+      case 'dark':
+        return ThemeMode.dark;
+      case 'system':
+      default:
+        return ThemeMode.system;
+    }
+  }
 }

frontend_splatournament_manager/pubspec.yaml

@@ -40,6 +40,7 @@ dependencies:
   intl: ^0.20.2
   flutter_secure_storage: ^10.0.0
   jwt_decoder: ^2.0.1
+  shared_preferences: ^2.3.3
 
 dev_dependencies:
   flutter_test: