import 'package:flutter/material.dart';

​

class MyNavigationBar extends StatefulWidget {

  final List<NavigationDestination> destinations;

  final NavigationDestinationLabelBehavior? labelBehavior;

  final int selectedIndex;

  final void Function(int index) onItemTap;

  final Color? backgroundColor;

​

  const MyNavigationBar({

    Key? key,

    required this.onItemTap,

    required this.destinations,

    this.selectedIndex = 0,

    this.backgroundColor,

    this.labelBehavior,

  }) : super(key: key);

​

  @override

  State<MyNavigationBar> createState() => _MyNavigationBarState();

}

​

class _MyNavigationBarState extends State<MyNavigationBar> {

  late int _selectedIndex;

​

  @override

  void initState() {

    super.initState();

​

    _selectedIndex = widget.selectedIndex;

  }

​

  @override

  Widget build(BuildContext context) {

    return NavigationBar(

      labelBehavior: widget.labelBehavior,

      backgroundColor: widget.backgroundColor,

      selectedIndex: _selectedIndex,

      onDestinationSelected: (int tappedIndex) {

        setState(() {

          _selectedIndex = tappedIndex;

        });

​

        widget.onItemTap(tappedIndex);

      },

      destinations: widget.destinations,

    );

  }

}