import 'package:flutter/material.dart';

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

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  int currentIndex = 0;

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('IndexedStack Example'),
        ),
        body: Column(
          children: [
            // 화면 전환을 위한 버튼들
            Row(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                RaisedButton(
                  child: Text('Screen 1'),
                  onPressed: () {
                    setState(() {
                      currentIndex = 0;
                    });
                  },
                ),
                RaisedButton(
                  child: Text('Screen 2'),
                  onPressed: () {
                    setState(() {
                      currentIndex = 1;
                    });
                  },
                ),
                RaisedButton(
                  child: Text('Screen 3'),
                  onPressed: () {
                    setState(() {
                      currentIndex = 2;
                    });
                  },
                ),
              ],
            ),
            // 인덱스에 해당하는 화면을 표시하는 IndexedStack
            Expanded(
              child: IndexedStack(
                index: currentIndex,
                children: [
                  Container(
                    color: Colors.red,
                    child: Center(
                      child: Text('Screen 1'),
                    ),
                  ),
                  Container(
                    color: Colors.blue,
                    child: Center(
                      child: Text('Screen 2'),
                    ),
                  ),
                  Container(
                    color: Colors.green,
                    child: Center(
                      child: Text('Screen 3'),
                    ),
                  ),
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }
}