Flutter Entegrasyonlar Serisi : 1 -Localization

//yaml dosyamız

name: localizationornek
description: A new Flutter project.

 
version: 1.0.0+1

environment:
  sdk: ">=2.1.0 <3.0.0"

dependencies:
  flutter:
    sdk: flutter
  flutter_localizations:
    sdk: flutter
  provider: ^4.0.4
  shared_preferences: ^0.5.6+3
  
  # The following adds the Cupertino Icons font to your application.
  # Use with the CupertinoIcons class for iOS style icons.
  cupertino_icons: ^0.1.2

dev_dependencies:
  flutter_test:
    sdk: flutter
 
flutter:


  uses-material-design: true


  # localizations altındaki tüm dosyalar
  assets:
    - assets/localizations/
  



//main.dart------------------
 
import 'package:flutter/material.dart';
import 'RunApp.dart';

void main() {
  runApp(RunApp());
}
 


//RunApp.dart------------
 
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'GsLocalization/GsLocalization.dart';
import 'GsLocalization/LangSupported.dart';
import 'Wp/WpSplash/WpSplash.dart';
import 'package:flutter_localizations/flutter_localizations.dart';

class RunApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MultiProvider(
      providers: [
        ChangeNotifierProvider<GsLocalization>(create: (_) => GsLocalization(),lazy: false),
      ],
      child: Consumer<GsLocalization>(
        builder: (context, gsLocalization, child) {
          return MaterialApp(
            debugShowCheckedModeBanner: false,
            locale: gsLocalization.locale,
            supportedLocales: LangSupported.locales,
			localizationsDelegates: [
              GlobalMaterialLocalizations.delegate,
              GlobalWidgetsLocalizations.delegate,
            ],
            home: child,
          );
        },
        child: WpSplash(),
      ),
    );
  }
}




//WpSplash.dart------------

import 'package:flutter/material.dart';
import 'package:localizationornek/GsLocalization/GsLocalization.dart';
import 'package:provider/provider.dart';
import '../WpHome.dart';


class WpSplash extends StatefulWidget {
  @override
  _WpSplashState createState() => _WpSplashState();
}

class _WpSplashState extends State<WpSplash> {

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) async {
      
      final _gsLocalization = Provider.of<GsLocalization>(context, listen: false);

      await _gsLocalization.load();

    Navigator.of(context).pushReplacement( MaterialPageRoute(builder: (BuildContext context) => WpHome()));
 
    });
  }


  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.blueAccent,
      body: Center(
        child: Padding(
          padding: EdgeInsets.all(10),
          child: Column(mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              Text( "Slash Ekranı"  ,style: TextStyle(fontSize: 30,color: Colors.white,fontWeight: FontWeight.bold),),
              Text( "Uygulamanın başlangıç ayarlarını yapmak için en doğru yer...",style: TextStyle(fontSize: 13,color: Colors.white ),),
            ],
          ),
        ),
      ),
    );
  }
}





//WpHome.dart------------

import 'dart:ui';
import 'package:flutter/material.dart';
import 'package:localizationornek/GsLocalization/GsLocalization.dart';
import 'package:localizationornek/GsLocalization/LangKey.dart';
import 'package:provider/provider.dart';
 

class WpHome extends StatelessWidget {
  const WpHome({Key key}) : super(key: key);


  @override
  Widget build(BuildContext context) {

           final gsLocalization = Provider.of<GsLocalization>(context, listen: false);

           
    return Scaffold(
      appBar: AppBar(
        title: Text("Uygulamanın Dili : ${gsLocalization.locale.languageCode} - Telefonun Dili: ${window.locale.languageCode}"),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
        TextField( decoration: InputDecoration(hintText: "uygulamanın dili arapça ise sağa yaslanır", helperText:'bir şeyler yazın' ),),
          
            RaisedButton(child: Text(gsLocalization.getTranslated(LangKey.button_Ok)), onPressed:(){}),
            RaisedButton(child: Text(gsLocalization.getTranslated(LangKey.button_Iptal)), onPressed:(){}),

            Text("-----------------------------------------------------"),
            RaisedButton(child: Text("Arapça Yap"),onPressed:()=>gsLocalization.setLocale('ar')),
            RaisedButton(child: Text("İngilizce Yap"),onPressed:()=>gsLocalization.setLocale('en')),
            RaisedButton(child: Text("Türkçe Yap"),onPressed:()=>gsLocalization.setLocale('tr')),
          ],
        ),
      ),
 
    );
  }
}






//GsLocalization.dart------------------
 
import 'dart:convert';
import 'dart:ui';
import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:flutter/services.dart' show rootBundle;
import 'LangSupported.dart';
 
class GsLocalization with ChangeNotifier {
  Locale _locale = Locale(LangSupported.languageCodeList.contains(window.locale.languageCode) ? window.locale.languageCode : 'en','');
  Locale get locale => _locale;


 Map<dynamic, dynamic> _translated;
  String getTranslated(String langKey) =>_translated[langKey] ?? '** $langKey not found';

  Future<void> load() async {
    final SharedPreferences mSharedPreferences = await SharedPreferences.getInstance();
    String tempLanguageCode = mSharedPreferences.getString("languageCode") ?? "notfound";

 if(_locale.languageCode == tempLanguageCode ){
    String jsonLang = await rootBundle.loadString("assets/localizations/${_locale.languageCode}.json");
    _translated = json.decode(jsonLang);
    return;
   }

   
   if(tempLanguageCode == "notfound"){
    await mSharedPreferences.setString("languageCode", _locale.languageCode);
    String jsonLang = await rootBundle.loadString("assets/localizations/${_locale.languageCode}.json");
    _translated = json.decode(jsonLang);
      return;
   }


    _locale = Locale(tempLanguageCode, '');
    String jsonLang = await rootBundle.loadString("assets/localizations/${_locale.languageCode}.json");
    _translated = json.decode(jsonLang);
     notifyListeners();
  }

 
  Future<void> setLocale(String languageCode) async {
  if(_locale.languageCode == languageCode )  return;
   final SharedPreferences mSharedPreferences = await SharedPreferences.getInstance();
    await mSharedPreferences.setString("languageCode",  languageCode);
    _locale = Locale(languageCode, '');
    String jsonLang = await rootBundle.loadString("assets/localizations/${_locale.languageCode}.json");
    _translated = json.decode(jsonLang);
      notifyListeners();
  }
}




//LangKey.dart------------------

abstract class LangKey {
  static const button_Ok = "button_Ok";
  static const button_Iptal = "button_Iptal";
}


 

//LangSupported.dart------------------

import 'package:flutter/material.dart';

abstract class LangSupported {
  static List<String> get languageCodeList => languagesMap.entries.map((e) => e.key).toList(growable: false);
  static List<Locale> get locales => languagesMap.entries.map((e) => Locale(e.key, '')).toList(growable: false);
  // static List<String> get languageNamesList =>languagesMap.entries.map((e) => e.value).toList(growable: false);
 

  static final Map<String, String> languagesMap = <String, String>{
  "ar": "Arapça",
  "en": "English",
  "tr": "Türkçe"
  };

}