laad method

Implementation

Future<void> laad() async {
  final prefs = await SharedPreferences.getInstance();
  final stored = prefs.getString(_key);
  _mode = switch (stored) {
    'light'  => ThemeMode.light,
    'dark'   => ThemeMode.dark,
    _        => ThemeMode.system,
  };
  notifyListeners();
}