example i18n interface

i18n.dart

import 'package:flutter/widgets.dart';
import 'package:intl/intl.dart';
import 'package:photochatapp/services/i18n/wrappers/messages_all.dart';

class AppLocalizations {
  AppLocalizations(this.localeName);
  static Future<AppLocalizations> load(Locale locale) {
    String name = locale.toString();
    if (locale != null &&
        locale.countryCode != null &&
        locale.countryCode.isNotEmpty) {
      name = locale.languageCode;
    }
    String localeName = Intl.canonicalizedLocale(name);
    return initializeMessages(localeName).then((_) {
      return AppLocalizations(localeName);
    });
  }
  static AppLocalizations of(BuildContext context) {
    return Localizations.of<AppLocalizations>(context, AppLocalizations);
  }
  final String localeName;
  String get title {
    return Intl.message(
      'Mini Donkey',
      name: 'title',
      desc: 'Title for the application',
      locale: localeName,
    );
  }
  String get decodeResultScreenTitle {
    return Intl.message(
      'Here is Your Message!',
      name: 'decodeResultScreenTitle',
      desc: 'Text for the title of the decode result screen',
      locale: localeName,
    );
  }
}

class AppLocalizationsDelegate extends LocalizationsDelegate<AppLocalizations> {
  const AppLocalizationsDelegate();
  @override
  bool isSupported(Locale locale) => ['en', 'zh'].contains(locale.languageCode);
  @override
  Future<AppLocalizations> load(Locale locale) => AppLocalizations.load(locale);
  @override
  bool shouldReload(AppLocalizationsDelegate old) => false;
}