flutter_localization_tut

.\lib\localizations.dart

import 'package:flutter/material.dart';
import 'dart:async';
import 'package:intl/intl.dart';
import 'l10n/messages_all.dart';

class AppLocalizations {
  static Future<AppLocalizations> load(Locale locale) {
    final String name =
        locale.countryCode.isEmpty ? locale.languageCode : locale.toString();
    final String localeName = Intl.canonicalizedLocale(name);

    return initializeMessages(localeName).then((_) {
      Intl.defaultLocale = localeName;
      return AppLocalizations();
    });
  }

  static AppLocalizations of(BuildContext context) {
    return Localizations.of<AppLocalizations>(context, AppLocalizations);
  }

  title() => Intl.message(
        'Counter Tutorial',
        name: "title",
        desc: "Name of the tutorial",
      );

  text(counter) => Intl.message(
        'You have pushed the button $counter times:',
        name: "text",
        args: [counter],
        desc: "Our Text to localize",
      );
}

class AppLocalizationsDelegate extends LocalizationsDelegate<AppLocalizations> {
  const AppLocalizationsDelegate();

  @override
  bool isSupported(Locale locale) => ['en', 'de', 'ru'].contains(locale.languageCode);

  @override
  Future<AppLocalizations> load(Locale locale) => AppLocalizations.load(locale);

  @override
  bool shouldReload(AppLocalizationsDelegate old) => false;
}