import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: Text(widget.title),
      ),
      body: Stack(
        children: [
          Center(
            child: Column(
              mainAxisSize: MainAxisSize.min,
              children: [
                AnimatedSwitcher(
                  duration: const Duration(seconds: 2),
                  child: Text('Animated container: $_counter', key: Key(_counter.toString()),),
                ),
              ],
            ),
          ),
          Positioned.fill(
            child: Stack(
              children: [
                Positioned.fill(
                  child: Stack(
                    children: [
                      ColorFiltered(
                        colorFilter: ColorFilter.mode(
                          Colors.black54,
                          BlendMode.srcOut,
                        ),
                        child: Stack(
                          children: [
                            Positioned.fill(
                              child: Container(
                                decoration: const BoxDecoration(
                                  color: Colors.white,
                                  backgroundBlendMode: BlendMode.dstOut,
                                ),
                              ),
                            ),
                            Positioned(
                              top: 200,
                              left: 50,
                              child: DecoratedBox(
                                decoration: BoxDecoration(
                                  color: Colors.white,
                                ),
                                child: SizedBox.square(dimension: 100),
                              ),
                            ),
                          ],
                        ),
                      ),
                    ],
                  ),
                ),
              ],
            ),
          ),
        ],
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ),
    );
  }
}