Flutter pass data from one tab to another - flutter

Question

Grettings i have this code
import 'package:flutter/material.dart';
import 'package:simplifly/classes/Database/Users.dart';
import 'package:simplifly/dashbaord/chat.dart';
import 'package:simplifly/dashbaord/collection.dart';
import 'package:simplifly/dashbaord/home.dart';
import 'package:simplifly/dashbaord/mytrip.dart';
import 'media.dart';
class Dashboardmain extends StatefulWidget {
final User usr;
Dashboardmain({Key key, #required this.usr}) : super(key: key);
#override
_Dashboardmain createState() => _Dashboardmain();
}
class _Dashboardmain extends State<Dashboardmain> {
String group="";
int _currentIndex=0;
void onTabTapped(int index) {
setState(() {
_currentIndex = index;
});
}
#override
Widget build(BuildContext context) {
return DefaultTabController(
length: 4,
child: Scaffold(
appBar: AppBar(title: Text('Sami'),),
body: [
Home(),
Media(),
MyTrip(),
Collection(),
Chat()
].elementAt(_currentIndex),
bottomNavigationBar: BottomNavigationBar(
type: BottomNavigationBarType.fixed,
// this will be set when a new tab is tapped
onTap: onTabTapped, // new
currentIndex: _currentIndex,
items: [
BottomNavigationBarItem(
icon: ImageIcon(
AssetImage(
"images/home_home.png",
),
),
title: new Text('Home'),
),
BottomNavigationBarItem(
icon: ImageIcon(
AssetImage("images/home_media.png"),
),
title: new Text('Media'),
),
BottomNavigationBarItem(
icon: ImageIcon(
AssetImage("images/home_myTrip.png"),
),
title: Text('My trips')),
BottomNavigationBarItem(
icon: ImageIcon(
AssetImage("images/home_collection.png"),
),
title: Text('Collection')),
BottomNavigationBarItem(
icon: ImageIcon(
AssetImage("images/home_chat.png"),
),
title: Text('Chat'))
],
),
),
);
}
}
by default the Home is displayed and it show data from firebase in a list
the other tabs for example media depends on the data in the home
what i want is when i press on a list item in the Home to pass data to the media class
how this can me done
is declaring a global variable will solve it or is there any solution for that
thanks