الگوهای طراحی در Flutter MVVM

// models/counter_model.dart
class CounterModel {
  int counter;

  CounterModel({this.counter = 0});
}

// viewmodels/counter_view_model.dart
import 'package:flutter/material.dart';
import '../models/counter_model.dart';

class CounterViewModel extends ChangeNotifier {
  CounterModel _counterModel = CounterModel();

  int get counter => _counterModel.counter;

  void increment() {
    _counterModel.counter++;
    notifyListeners();
  }

  void decrement() {
    _counterModel.counter--;
    notifyListeners();
  }
}

// main.dart
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'viewmodels/counter_view_model.dart';
import 'views/counter_page.dart';

void main() {
  runApp(
    ChangeNotifierProvider(
      create: (context) => CounterViewModel(),
      child: MyApp(),
    ),
  );
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: CounterPage(),
    );
  }
}

// views/counter_page.dart
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import '../viewmodels/counter_view_model.dart';

class CounterPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('MVVM Counter'),
      ),
      body: Center(
        child: Consumer(
          builder: (context, counterViewModel, child) {
            return Text(
              'Counter: ${counterViewModel.counter}',
              style: TextStyle(fontSize: 24),
            );
          },
        ),
      ),
      floatingActionButton: Column(
        mainAxisAlignment: MainAxisAlignment.end,
        children: [
          FloatingActionButton(
            onPressed: () => context.read().increment(),
            child: Icon(Icons.add),
          ),
          SizedBox(height: 8),
          FloatingActionButton(
            onPressed: () => context.read().decrement(),
            child: Icon(Icons.remove),
          ),
        ],
      ),
    );
  }
}