is there a visual indication of the "default" button

["Norman Black" <stonybrk ix netcom com>]

In my dialog(s) is use gtk_widget_grab_default to set the "default" button
for the dialog. This works but I see no indication of this on the screen.
When a button gets the focus by using the tab key it is drawn with a black
border, but this is focus and not "default".

Does GTK have a visual indication of the default button, and if so how do I
activate it. By visual indication I mean something like Windows, the Mac,
and others do.

Best Regards,
Norman Black
Stony Brook Software