X11 widget of a gtk window

[Thomas Krebs <Thomas_Krebs gmx de>]

Hi,

I'm using gtk and I need to get the X11 Widget of a window created with
gtk. I can get the GtkWidget by using:
GtkWidget* gtk_widget = GTK_WIDGET(window);

But I need the X11 Widget (the WidgetRec struture) of that window. Is
there a way to access that? Does it exist at all in gtk?