examples/platform_view/lib/main.dart

// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'dart:async';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

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

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Platform View',
      theme: ThemeData(
        primarySwatch: Colors.grey,
      ),
      home: const MyHomePage(title: 'Platform View'),
    );
  }
}

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

  final String title;

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

class _MyHomePageState extends State<MyHomePage> {
  static const MethodChannel _methodChannel =
      MethodChannel('samples.flutter.io/platform_view');

  int _counter = 0;

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

  static Widget get _buttonText => switch (defaultTargetPlatform) {
    TargetPlatform.android => const Text('Continue in Android view'),
    TargetPlatform.iOS     => const Text('Continue in iOS view'),
    TargetPlatform.windows => const Text('Continue in Windows view'),
    TargetPlatform.macOS   => const Text('Continue in macOS view'),
    TargetPlatform.linux   => const Text('Continue in Linux view'),
    TargetPlatform.fuchsia => throw UnimplementedError('Platform not yet implemented'),
  };

  Future<void> _launchPlatformCount() async {
    final int? platformCounter =
        await _methodChannel.invokeMethod('switchView', _counter);
    setState(() {
      _counter = platformCounter!;
    });
  }

  @override
  Widget build(BuildContext context) => Scaffold(
        appBar: AppBar(
          title: Text(widget.title),
        ),
        body: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: <Widget>[
            Expanded(
              child: Center(
                child: Column(
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: <Widget>[
                    Text(
                      'Button tapped $_counter time${ _counter == 1 ? '' : 's' }.',
                      style: const TextStyle(fontSize: 17.0),
                    ),
                    Padding(
                      padding: const EdgeInsets.all(18.0),
                      child: ElevatedButton(
                        onPressed: _launchPlatformCount,
                        child: _buttonText,
                      ),
                    ),
                  ],
                ),
              ),
            ),
            Container(
              padding: const EdgeInsets.only(bottom: 15.0, left: 5.0),
              child: Row(
                children: <Widget>[
                  Image.asset('assets/flutter-mark-square-64.png', scale: 1.5),
                  const Text(
                    'Flutter',
                    style: TextStyle(fontSize: 30.0),
                  ),
                ],
              ),
            ),
          ],
        ),
        floatingActionButton: FloatingActionButton(
          onPressed: _incrementCounter,
          tooltip: 'Increment',
          child: const Icon(Icons.add),
        ),
      );
}