XComposite Overlay Window usage

[Jochen Keil]

Hello,

I'm trying to write an application with which I'd like to draw "over"
other windows. So far my attempts have been:

* Drawing right into other window's backing pixmap
(XCompositeNameWindowPixmap). This messes up some applications but can
be fixed by calling XClearArea. However, this produces a Damage Event
which is also not nice.

* Drawing to an transparent overlay window I create myself: Main problem
is to keep this window always on top of of all the other windows
(repeated calls to XRaiseWindow, possible flicker) + requires a
compositing manager.

* Drawing to the XComposite overlay window (XCompositeGetOverlayWindow),
respectively a child window of it. Only works if the overlay window is
mapped, but then everything appears to "frozen". I realize that I can
handle this by using XFixes + shapes for input and drawing all windows
to the overlay window, but then I am doing what a compositor is meant for.

So my question is: Can I somehow draw on a transparent surface/window
above all other windows without semi-implementing a compositing manager?

Thanks and best wishes,

Jochen

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 198 bytes
Desc: OpenPGP digital signature
URL: <http://lists.x.org/archives/xorg/attachments/20130923/32811f5f/attachment.pgp>