class _MyHomePageState extends State<MyHomePage> {
  int weight = 70;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: WeightSlider(
            weight: weight,
            minWeight: 40,
            maxWeight: 120,
            onChange: (val) => setState(() => this.weight = val),
          ),
        ),
    );
  }
}