Qt/X11: How to make a QWidget override-redirect / calling XChangeWindowAttributes() with QWidget

Question

Does anybody has an example how to make a QWidget instance (as toplevel window) override-redirect with the X11 library? the following code doesn't work:

        QWidget* widget = new QWidget();
        XSetWindowAttributes attr;
        attr.override_redirect = true;
        XChangeWindowAttributes(display, widget->winId(), CWOverrideRedirect, &attr);
        widget->show();

Does anybody has an idea? The bigger toplevel-problem i try to solve is the following: QWidget / X11: Prevent window from beeing activated/focussed by mouse clicks

Thank you very much in advance! Frime