examples/api/lib/material/bottom_navigation_bar/bottom_navigation_bar.2.dart

// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Flutter code sample for BottomNavigationBar

import 'package:flutter/material.dart';

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  static const String _title = 'Flutter Code Sample';

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      title: _title,
      home: MyStatefulWidget(),
    );
  }
}

class MyStatefulWidget extends StatefulWidget {
  const MyStatefulWidget({super.key});

  @override
  State<MyStatefulWidget> createState() => _MyStatefulWidgetState();
}

class _MyStatefulWidgetState extends State<MyStatefulWidget> {
  int _selectedIndex = 0;
  final ScrollController _homeController = ScrollController();

  Widget _listViewBody() {
    return ListView.separated(
        controller: _homeController,
        itemBuilder: (BuildContext context, int index) {
          return Center(
            child: Text(
              'Item $index',
            ),
          );
        },
        separatorBuilder: (BuildContext context, int index) => const Divider(
              thickness: 1,
            ),
        itemCount: 50);
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('BottomNavigationBar Sample'),
      ),
      body: _listViewBody(),
      bottomNavigationBar: BottomNavigationBar(
        items: const <BottomNavigationBarItem>[
          BottomNavigationBarItem(
            icon: Icon(Icons.home),
            label: 'Home',
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.open_in_new_rounded),
            label: 'Open Dialog',
          ),
        ],
        currentIndex: _selectedIndex,
        selectedItemColor: Colors.amber[800],
        onTap: (int index) {
          switch (index) {
            case 0:
              // only scroll to top when current index is selected.
              if (_selectedIndex == index) {
                _homeController.animateTo(
                  0.0,
                  duration: const Duration(milliseconds: 500),
                  curve: Curves.easeOut,
                );
              }
              break;
            case 1:
              showModal(context);
              break;
          }
          setState(
            () {
              _selectedIndex = index;
            },
          );
        },
      ),
    );
  }

  void showModal(BuildContext context) {
    showDialog(
      context: context,
      builder: (BuildContext context) => AlertDialog(
        content: const Text('Example Dialog'),
        actions: <TextButton>[
          TextButton(
            onPressed: () {
              Navigator.pop(context);
            },
            child: const Text('Close'),
          )
        ],
      ),
    );
  }
}