import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: Home(),
    );
  }
}

class Home extends StatelessWidget {
  const Home({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(),
      body: Center(
        child: MyButton(),
      ),
    );
  }
}

class MyButton extends StatelessWidget {
  const MyButton({
    Key key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return FlatButton(
      child: Text(
        "Click to show snackbar",
        style: TextStyle(color: Theme.of(context).primaryColor),
      ),
      onPressed: () {
        Scaffold.of(context).showSnackBar(
          SnackBar(
            content: Text("This is a snackbar!"),
          ),
        );
      },
    );
  }
}