// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
// for details. 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';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  final String title;

  const MyHomePage({
    Key? key,
    required this.title,
  }) : super(key: key);

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int currentPage = 0;
  late PageController controller;

  @override
  void initState() {
    super.initState();
    controller = PageController();
  }
  
  @override
  Widget build(BuildContext context) {
    try {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
        backgroundColor: Colors.transparent,
        elevation: 0
      ),
      extendBodyBehindAppBar: currentPage == 1, //conditional breaks pageview
      body: PageView(
        controller: controller,
        onPageChanged: (int index) {
          setState(() {
            currentPage = index;
          });
        },
        children: [
          Container(color: Colors.blue),
          Container(color: Colors.red),
          Container(color: Colors.green),
        ]
      ),
      bottomNavigationBar: BottomNavigationBar(
        currentIndex: currentPage,
        onTap: (int index) {
          controller.jumpToPage(index);
        },
        items: const [
          BottomNavigationBarItem(
            label: "1",
            icon: Icon(Icons.circle)
          ),
          BottomNavigationBarItem(
            label: "2",
            icon: Icon(Icons.square)
          ),
          BottomNavigationBarItem(
            label: "3",
            icon: Icon(Icons.accessible)
          ),
        ]
      )
    );
    } catch (e) {
      print(e);
      return Container();
    }
  }
}