How can I persist BottomNavigationBar across all screens in Flutter - flutter

Question

I have BottomNavigationBar in flutter & called separate widgets for each tab. For example I am having button into that widget which redirects to new screen, I want that BottomNavigationBar should be persisted in new screen as well. I have checked couple of articles but unable to understand. Below is code for BottomTabNavigationBar
import 'package:flutter/material.dart';
import 'package:timeout_dubai/fragments/HomeFragment.dart';
import 'package:timeout_dubai/fragments/MtTimeFragment.dart';
import 'package:timeout_dubai/fragments/MyLocFragment.dart';
import 'package:timeout_dubai/fragments/ThingsLoveFragment.dart';
class LoginScreen extends StatefulWidget {
#override
State<StatefulWidget> createState() {
return _HomeState();
}
}
class _HomeState extends State<LoginScreen> {
int _currentIndex = 0;
GlobalKey globalKey = new GlobalKey(debugLabel: 'btm_app_bar');
final List<Widget> _children = [
new HomeFragment(),
new ThingsLoveFragment(),
new MyLocFragment(),
new MyTimeFragment()
];
#override
Widget build(BuildContext context) {
return Scaffold(
body: _children[_currentIndex],
bottomNavigationBar: BottomNavigationBar(
type: BottomNavigationBarType.fixed,
onTap: onTabTapped,
key: globalKey,
currentIndex: _currentIndex,
items: [
BottomNavigationBarItem(
icon: Icon(Icons.home,),
title: Text('Home'),
),
BottomNavigationBarItem(
icon: Icon(Icons.favorite),
title: Text('Things I Love'),
),
BottomNavigationBarItem(
icon: Icon(Icons.location_on),
title: Text('My Locations'),
),
BottomNavigationBarItem(
icon: Icon(Icons.person),
title: Text('My Time Out')
),
],
),
);
}
void onTabTapped(int index) {
print("Index $index");
setState(() {
_currentIndex = index;
});
}
}