Navigation with rootPages' BuildContext

MainTabOrDetailPage.dart

class MainTabOrDetailPage extends StatefulWidget {
  final BuildContext rootContext;
  StudentMainTab({@required this.rootContext});
  @override
  State<StatefulWidget> createState() {
    return _MainTabOrDetailPage();
  }
}

class _MainTabOrDetailPage extends State<MainTabOrDetailPage> {
  @override
  Widget build(BuildContext context) {
    return Navigator(
        onGenerateRoute: (RouteSettings settings) {
          return new MaterialPageRoute(
              settings: settings,
              builder: (BuildContext context) {
                return Scaffold(
                        body: 
                        //List
                        ,
                        floatingActionButton: FloatingActionButton(
                          child: Icon,
                          onPressed: () {
                            Navigator.push(
                                widget.rootContext,
                                MaterialPageRoute(
                                    builder: (context) =>
                                        StudentRequestPage()));
                          },
                        ));
              });
        });
  }
}