flutter_3.35_preview_material_app_with_l10n_function.dart

Widget materialAppWrapper(Widget child) {
  return Builder(   // <-- Wrap with Builder
    builder: (context) {
      final locale = Localizations.maybeLocaleOf(context);    // <-- Access localizations

      return MaterialApp(
        theme: ThemeData(
          colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
          useMaterial3: true,
        ),
        darkTheme: ThemeData(
          colorScheme: ColorScheme.fromSeed(
            seedColor: Colors.deepPurple,
            brightness: Brightness.dark,
          ),
          useMaterial3: true,
        ),
        locale: locale,
        supportedLocales: AppLocalizations.supportedLocales,
        localizationsDelegates: const [
          AppLocalizations.delegate,
          GlobalMaterialLocalizations.delegate,
          GlobalWidgetsLocalizations.delegate,
          GlobalCupertinoLocalizations.delegate,
        ],
        home: Scaffold(
          body: child,
        ),
      );
    },
  );
}