// 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.

import 'package:flutter/material.dart';

/// Flutter code sample for [BottomNavigationBar].

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

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

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(home: BottomNavigationBarExample());
  }
}

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

  @override
  State<BottomNavigationBarExample> createState() =>
      _BottomNavigationBarExampleState();
}

class _BottomNavigationBarExampleState
    extends State<BottomNavigationBarExample> {
  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,
                );
              }
            case 1:
              showModal(context);
          }
          setState(() {
            _selectedIndex = index;
          });
        },
      ),
    );
  }

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