main.dart

class MyWidget extends StatefulWidget {
  @override
  LoginState createState() {
    return MyState();
  }
}

class MyState extends State<Login> {
  int value = 0;

  @override
  Widget build(BuildContext context) => Scaffold(
        appBar: AppBar(
          title: Text('Flutter + Dartea = ❤'),
        ),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            crossAxisAlignment: CrossAxisAlignment.center,
            children: <Widget>[
              Text(
                '$value',
                style: Theme.of(context).textTheme.display1,
              ),
              Padding(
                child: RaisedButton.icon(
                  label: Text('Increment'),
                  icon: Icon(Icons.add),
                  onPressed: () => setState(() => value++),
                ),
                padding: EdgeInsets.all(5.0),
              ),
              RaisedButton.icon(
                label: Text('Decrement'),
                icon: Icon(Icons.remove),
                onPressed: () => setState(() => value--),
              ),
            ],
          ),
        ),
      );
}