class _ParentWidgetState extends State<MainFeedPage> with AfterLayoutMixin<MainFeedPage>{
    String empName;
    Future<List> getUserData() async{
      final response = await http.post("http://172.16.161.34:8080/ebs/cfs/android_test_app/accessfile.php?q=getUserData",body:{
      "emp_id": widget.empId,
      });
      var dataUser = jsonDecode(response.body);
      empName = dataUser[0]['name'];

      return null;
    }

    @override
  void initState() {
    super.initState();
    BackButtonInterceptor.add(myInterceptor);
  }

  @override
  void dispose() {
    BackButtonInterceptor.remove(myInterceptor);
    super.dispose();
  }

    bool myInterceptor(bool stopDefaultButtonEvent) {
    //print("BACK BUTTON!"); // Do some stuff.
    return true;
  }

    @override
    void afterFirstLayout(BuildContext context) {
      // Calling the same function "after layout" to resolve the issue.
      getUserData();
    }

  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    return new MaterialApp(
      title: 'ALTURAS TEST APP',
      debugShowCheckedModeBanner: false,
      color: Colors.white,
      home: DefaultTabController(
        length: 3,
        child: new Scaffold(
          appBar: AppBar(
            iconTheme: new IconThemeData(color: Colors.black ),
            textTheme: TextTheme(
                title: TextStyle(
                  color: Colors.black,
                )
            ),
            title: Text(empName),
            backgroundColor: Colors.white,
            actions: <Widget>[
              IconButton(icon: Icon(Icons.shopping_cart),onPressed:(){
                getUserData();
              },),
              IconButton(icon: Icon(Icons.person),onPressed:(){},),
            ],
            elevation: 0.0,
          ),
          drawer: Drawer(

            child: ListView(
              // Important: Remove any padding from the ListView.
              padding: EdgeInsets.zero,
              children: <Widget>[
                DrawerHeader(
                  child: Text(''),
                  decoration: BoxDecoration(
                    color: Colors.white,
                  ),
                ),
                ListTile(
                  title: Text('Item 1'),
                  onTap: () {
                    // Update the state of the app
                    // ...
                  },
                ),
                ListTile(
                  title: Text('Item 2'),
                  onTap: () {
                    // Update the state of the app
                    // ...
                  },
                ),
              ],
            ),

          ),
          body: new TabBarView(
            physics: NeverScrollableScrollPhysics(),
            children :<Widget>[
              new Screen1(),
              new Screen2(),
              new Screen3()
            ],
          ),
          bottomNavigationBar: new TabBar(

            tabs: [
              Tab(
                text: "Home",
                icon: new Icon(Icons.home,),
              ),
              Tab(
                text: "Profile",
                icon: new Icon(Icons.perm_identity),
              ),
              Tab(
                text: "Settings",
                icon: new Icon(Icons.settings),
              )
            ],
            labelStyle: TextStyle(fontSize: 12.0),
            labelColor: Colors.black,
            unselectedLabelColor: Colors.black38,
            indicatorSize: TabBarIndicatorSize.label,
            indicatorPadding: EdgeInsets.all(1.0),
            indicatorColor: Colors.black,
          ),
          backgroundColor: Colors.white,
        ),
      ),
    );
  }
}