Re: Compositing widgets in GTK2?

[Havoc Pennington <hp redhat com>]

Brett Granger <bdgranger alum mit edu> writes: 
> I tried using the pixmap engine, and buttons do indeed seem to be able
> to be translucent.  However, eventboxes don't seem to be able to (I
> always get the png composited with the default gray background).  The
> only difference between the two as far as I can tell is that buttons
> use the BOX function whereas eventboxes use the FLAT_BOX function.
> However, I can't see in the pixbuf engine source code why the two
> should behave differently.

Sorry for the late reply, was just looking at old messages. 

The difference is that buttons have the GTK_NO_WINDOW flag set,
i.e. they do not have their own GdkWindow associated with them.

> Do I have to use the pixmap/pixbuf engine to achieve this kind of
> functionality, or is there some other way to have "layered" widgets
> composite on top of each other?

You sort of need to use a specific theme engine if you want to have
precise control over the details of how widgets are drawn.

Havoc