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 'package:flutter/material.dart';

void main() => runApp(const MyApp(Colors.blue));

@pragma('vm:entry-point')
void topMain() => runApp(const MyApp(Colors.green));

@pragma('vm:entry-point')
void bottomMain() => runApp(const MyApp(Colors.purple));

class MyApp extends StatelessWidget {
  const MyApp(this.color, {Key key}) : super(key: key);

  final Color color;

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: color as MaterialColor,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key key, this.title}) : super(key: key);
  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            const Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '0',
              style: Theme.of(context).textTheme.headline4,
            ),
            TextButton(
              onPressed: () {},
              child: const Text('Add'),
            ),
            TextButton(
              onPressed: () {},
              child: const Text('Next'),
            ),
          ],
        ),
      ),
    );
  }
}