KWinModule for several "kwin" processes

[Lubos Lunak]

On Thursday 09 March 2006 05:56, Andriy Rysin wrote:
> Got a question which came from bug 107877
> <https://bugs.kde.org/show_bug.cgi?id=107877>
> There's switching policies "per window" and "per application" for kxkb.
> It's implemented in a way that kxkb registers itself as a listener with
> KWinModule and gets notified when active window is changed. Now there's
> a case when user have multiple screens and don't use Xinerama he'll have
> several instances of kwin process running. kxkb currently registers
> itself only with 1st one, so whenever user switches to other screens
> kxkb never gets notified when active window is changed and thus "per
> window" and "per application" do not work. When user switches back to
> screen 0 everything is fine.

 Short answer: Non-xinerama multihead is not supported by KDE and nobody works 
on it. The only "support" we have is a hack to start one instance per screen 
of some important apps like kwin/kdesktop/kicker. Given that Xinerama mostly 
works quite fine I don't see anybody spending the effort on providing a 
proper support or even just finding out what that'd require, but if there's a 
volunteer you're of course welcome.

> The question is whether there's a way to get hold of KWinModule for
> other screens to be able to listen to their messages?

 Fast&simple solution: Enqueue the bugreport next to the all other 
non-xinerama multihead bugreport that nobody cares about, recommend the user 
to use xinerama and wait for all such users to get bored with non-xinerama or 
for somebody to fix it.

 Extend-the-hack solution: Fork kxkb per screen just like kwin/kdesktop/kicker 
etc. do in their main.cpp .

 Fixing-KWinModule solution: All netwm.* classes seem to have proper support 
for multiple screens, so just extending KWinModule to use proper screen 
number and root window could fix your problem.

-- 
Lubos Lunak
KDE developer
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