Qt-Copy causing rendering issues

[Fredrik Höglund]

On Thursday 09 August 2007 22:33, Robert Knight wrote:
> > What sort of problems?
> 
> It thinks my desktop supports ARGB visuals when it doesn't.  This
> means that where you would normally get a plain color when X erases a
> window surface before drawing on it, I get mostly-black garbage
> instead.  Scrolling performance suffers horribly too.

The X server always supports the ARGB visual when the Composite
extension is enabled, regardless of whether a composition manager
is running or not.

When you're not running a composition manager, these windows are
automatically redirected (redirected to offscreen storage with
automatic updates). But they should be indistinguishable from regular
windows in this case.

That said, I do see the X server occasionally getting confused about
the clip lists, when you have a regular window obscuring an ARGB
window after switching virtual desktops. I'm not seeing the problems
you are describing though, so it may be a problem in the X.org
version you're using, or in the driver.

> What I used to do in Konsole was to check the result of
> KWindowSystem::compositingActive() and only attempting to find a true
> color visual if it returned true.

If applications only select the ARGB visual when a composition
manager is running, you will have to restart all applications that
support transparency after enabling the compositing features
in KWin. It may still be the preferred solution though.

Regards,
Fredrik