initial_1.dart

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text(widget.title)),
      body: Container(),
      floatingActionButton: ExpandableDraggableFab(
        childrenCount: 1,
        distance: 10,      
        children: [
          FloatingActionButton(
              heroTag: "addBtn",
              onPressed: () => Navigator.of(context).pushNamed('/add'),
              child: const Icon(Icons.add)),
          ),
        ],
      ),
    );
  }
}