OnSharedPreferenceChangeListener for Flutter - flutter

Question

In Android, you can do the following to listen to shared preference change
SharedPreferences.OnSharedPreferenceChangeListener spChanged = new
SharedPreferences.OnSharedPreferenceChangeListener() {
#Override
public void onSharedPreferenceChanged(SharedPreferences sharedPreferences,
String key) {
// your stuff here
}
};
Is it possible to do this using flutter? I have read through the official flutter shared_preference and this features seems not yet implemented.
Is there any other library or ways to achieve the above without diving into native code. Thanks.

Answer 1

You can easily "listen" to SharedPreferences using a package like flutter_riverpod.
Initialize sharedPreferences
SharedPreferences? sharedPreferences;
Future<void> main() async {
WidgetsFlutterBinding.ensureInitialized();
sharedPreferences = await SharedPreferences.getInstance();
runApp(const ProviderScope(child: MyApp()));
}
Create the stateProvider
import 'package:hooks_riverpod/hooks_riverpod.dart';
final keepOnTopProvider = StateProvider<bool>((ref) {
return sharedPreferences?.getBool('on_top') ?? true;
});
Update your UI when something changes
class SettingsView extends ConsumerWidget {
const SettingsView({Key? key}) : super(key: key);
#override
Widget build(BuildContext context, WidgetRef ref) {
bool onTop = ref.watch(keepOnTopProvider);
return Scaffold(
appBar: AppBar(title: const Text('Settings'), centerTitle: false),
body: ListView(
padding: const EdgeInsets.symmetric(horizontal: 12),
children: [
SwitchListTile(
title: const Text('Keep on top'),
value: onTop,
onChanged: (value) async {
sharedPreferences?.setBool('on_top', value);
ref.read(keepOnTopProvider.notifier).state = value;
await windowManager.setAlwaysOnTop(value);
},
),
],
),
);
}
}

Answer 2

As a work around, add the following codes to your main():
void funTimerMain() async {
// here check any changes to SharedPreferences, sqflite, Global Variables etc...
if (bolAnythingChanged) {
// do something
// 'refresh' any page you want (below line using Redux as example)
GlobalVariables.storeHome.dispatch(Actions.Increment);
}
// recall this timer every x milliseconds
new Future.delayed(new Duration(milliseconds: 1000), () async {
funTimerMain();
});
}
// call the timer for the first time
funTimerMain();