NavigationDrawer flutter home_page.dart

home_page.dart

import 'package:drawer_demo/fragments/first_fragment.dart';
import 'package:drawer_demo/fragments/second_fragment.dart';
import 'package:drawer_demo/fragments/third_fragment.dart';
import 'package:flutter/material.dart';

class DrawerItem {
  String title;
  IconData icon;
  DrawerItem(this.title, this.icon);
}

class HomePage extends StatefulWidget {
  final drawerItems = [
    new DrawerItem("Fragment 1", Icons.rss_feed),
    new DrawerItem("Fragment 2", Icons.local_pizza),
    new DrawerItem("Fragment 3", Icons.info)
  ];

  @override
  State<StatefulWidget> createState() {
    return new HomePageState();
  }
}

class HomePageState extends State<HomePage> {
  int _selectedDrawerIndex = 0;

  _getDrawerItemWidget(int pos) {
    switch (pos) {
      case 0:
        return new FirstFragment();
      case 1:
        return new SecondFragment();
      case 2:
        return new ThirdFragment();

      default:
        return new Text("Error");
    }
  }
  
  _onSelectItem(int index) {
    setState(() => _selectedDrawerIndex = index);
    Navigator.of(context).pop(); // close the drawer
  }

  @override
  Widget build(BuildContext context) {
    var drawerOptions = <Widget>[];
    for (var i = 0; i < widget.drawerItems.length; i++) {
      var d = widget.drawerItems[i];
      drawerOptions.add(
        new ListTile(
          leading: new Icon(d.icon),
          title: new Text(d.title),
          selected: i == _selectedDrawerIndex,
          onTap: () => _onSelectItem(i),
        )
      );
    }

    return new Scaffold(
      appBar: new AppBar(
        // here we display the title corresponding to the fragment
        // you can instead choose to have a static title
        title: new Text(widget.drawerItems[_selectedDrawerIndex].title),
      ),
      drawer: new Drawer(
        child: new Column(
          children: <Widget>[
            new UserAccountsDrawerHeader(
                accountName: new Text("John Doe"), accountEmail: null),
            new Column(children: drawerOptions)
          ],
        ),
      ),
      body: _getDrawerItemWidget(_selectedDrawerIndex),
    );
  }
}

How can manage the Back stack of fragments. Suppose One Fragment is open, then from navigation drawer open Second Fragment and then open Third Fragment.

1. how back press will work means how to override back button?
2. I want to go previous fragment from where i came.

Did somebody get the solution of this problem?