import 'package:shared_preferences/shared_preferences.dart'; class SharedPrefSingleton { static final SharedPrefSingleton _instance = SharedPrefSingleton._internal(); factory SharedPrefSingleton() => _instance; SharedPrefSingleton._internal(); late SharedPreferences _pref; Future initialize() async { _pref = await SharedPreferences.getInstance(); } Future setAutoFirewall(bool ok) => _pref.setBool("auto_firewall", ok); bool get autoFirewall => _pref.getBool("auto_firewall") ?? true; Future setAppTheme(bool ok) => _pref.setBool("app_theme", ok); // false = dark, true = light bool get appTheme => _pref.getBool("app_theme") ?? false; Future setSavedConnection(String config) => _pref.setString("saved_connection", config); String get savedConnection => _pref.getString("saved_connection") ?? "[]"; }