Adaptive Locale

Inspired by Adaptive Theme

The easiest way to handle Locales in your Flutter app. Allows you to set the locale dynamically and get the locale being used and all supported locales. It also preserves locale changes across app restarts.

Getting Started

Add following dependency to your pubspec.yaml

dependencies:
  adaptive_locale: <latest_version>

Recommendations

Use packages for app internationalization like flutter_localizations and intl.

dependencies:
  flutter_localizations:
    sdk: flutter
  intl: <latest_version>

Initialization

Import the package.

import 'package:adaptive_locale/adaptive_locale.dart';

You need to ensure proper package initialization with the following:

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await AdaptiveLocale.ensureInitialized();
  runApp(const MyApp());
}

You need to wrap your MaterialApp or CupertinoApp with AdaptiveLocale in order to manage locales.

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return AdaptiveLocale(
      localizationsDelegates: AppLocalizations.localizationsDelegates,
      supportedLocales: AppLocalizations.supportedLocales,
      builder: (localizationsDelegates, supportedLocales, currentLocale) {
        return MaterialApp(
          localizationsDelegates: localizationsDelegates,
          supportedLocales: supportedLocales,
          locale: currentLocale,
          title: 'Adaptive Locale Example',
          home: const Screen(),
        );
      },
    );
  }
}

Now that you have initialized your app as mentioned above. It's very easy manage the locales.

Getting all the supported locales

final Iterable<Locale> locales = AdaptiveLocale.of(context).supportedLocales;

Getting current locale

final Locale? locale = AdaptiveLocale.of(context).locale;

If locale is null it is because the locale is being used according to the system.

Setting locale to use

AdaptiveLocale.of(context).locale = const Locale('es');

This fails if the Locale to be set is not among the supported ones. It is recommended to check AdaptiveLocale.of(context).supportedLocales first.

If you set null, it means that it will use the system-specific Locale.

Warning

This package uses shared_preferences plugin internally to persist locale changes. If your app uses shared_preferences which might be the case all the time, clearing your shared_preferences at the time of logging out or signing out might clear these preferences too. Be careful not to clear these preferences if you want it to be persisted.

You can use AdaptiveLocale.prefKey to exclude it while clearing the all the preferences.

Or you can call AdaptiveLocale.of(context).persist() method after clearing the preferences to make it persistable again as shown below.

final prefs = await SharedPreferences.getInstance();
await prefs.clear();
AdaptiveLocale.of(context).persist();