Nested Widgets Test

main.dart

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Nested Widgets Test',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const WidgetA(),
    );
  }
}


/*
*   WidgetA
* */

class WidgetA extends StatefulWidget {
  const WidgetA({super.key});

  @override
  State<WidgetA> createState() => _WidgetAState();
}

class _WidgetAState extends State<WidgetA> {
  int _stateCounterA = 0;

  void _incrementCounter() {
    setState(() {
      _stateCounterA++;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            const Text(
              'You have pushed the button this many times:',
            ),
            const SizedBox(height: 16,),
            Text('_stateCounterA: $_stateCounterA'),
            const SizedBox(height: 16,),
            WidgetB(counterB: _stateCounterA,),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

/*
*   WidgetB
* */
class WidgetB extends StatefulWidget {
  final int counterB;
  const WidgetB({Key? key, required this.counterB}) : super(key: key);

  @override
  State<WidgetB> createState() => _WidgetBState();
}

class _WidgetBState extends State<WidgetB> {
  late int _stateCounterB;

  @override
  void initState() {
    _stateCounterB = widget.counterB;
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Text('_stateCounterB: $_stateCounterB');
  }
}