[Flutter] Creating & Updating State in a Flutter Application

To create a Stateful widget:

1. Create a StatefulWidget

2. Create a State

class SGreeting extends StatefulWidget {

  @override

  SGreetingState createState() => SGreetingState()

}

class SGreetingState extends State {

  String greeting = "Hello State";

  void _toggleState () {

    var next = greeting == "Hello State" ? "Hello World" : "Hello State";

    setState(() {

      greeting = next;

    });

  }

  @override

  Widget build(BuildContext context) {

    // TODO: implement build

    return GestureDetector(

      onTap: this._toggleState,

      child: Text(

          this.greeting,

          style: TextStyle(

              fontSize:

          )

      )

    );

  }

}