showing transparent layout over a layout in Qt 4.8.4

showing transparent layout over a layout in Qt 4.8.4

I Like to show a label that having a animated gif image over a listwidget.
listwidget is in a horizontal widget. when i am trying to put that label
on window it aligned horizontally to list widget. I want to show it over
the Listwidget with transparent view.
QMovie *m= new QMovie("loadingImage.gif");
QLabel *l=new QLabel();
ui.mainlayout->add
l->setMovie(m);
m->start();
l->show();