import 'package:flutter/material.dart';
import 'package:provider/provider.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return ChangeNotifierProvider<AppState>(
      builder: (_) => AppState(),
      child: MaterialApp(
        title: 'Sandbox',
        home: Scaffold(
          body: Body(),
        ),
      ),
    );
  }
}

class AppState with ChangeNotifier {
  bool _isAwesome = true;

  bool get isAwesome => _isAwesome;

  String get awesomeText => _isAwesome ? "Totally awesome" : "Not so great";

  toggleAwesome() {
    _isAwesome = !_isAwesome;
    notifyListeners();
  }
}

class Body extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return SafeArea(
      child: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.spaceEvenly,
          children: <Widget>[
            Text(Provider.of<AppState>(context).awesomeText),
            RaisedButton(
              child: Text("Toggle awesomeness"),
              onPressed: Provider.of<AppState>(context).toggleAwesome,
            ),
            RaisedButton(
              child: Text("Open bottom sheet"),
              onPressed: () {
                showBottomSheet(
                    context: context, builder: (_) => BottomSheet());
              },
            )
          ],
        ),
      ),
    );
  }
}

class BottomSheet extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Container(
      color: Colors.grey,
      padding: EdgeInsets.all(38),
      alignment: Alignment.bottomCenter,
      height: 100,
      child: Text(Provider.of<AppState>(context).awesomeText),
    );
  }
}