Bug 246464

Summary:	KWin does not use composite effects for VLC window
Product:	[Plasma] kwin	Reporter:	Nikos Chantziaras <realnc>
Component:	general	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED NOT A BUG
Severity:	normal
Priority:	NOR
Version:	unspecified
Target Milestone:	---
Platform:	Gentoo Packages
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Nikos Chantziaras 2010-08-01 23:31:05 UTC

Version:           unspecified (using KDE 4.4.95) 
OS:                Linux

When using VLC with a skin, KWin doesn't drop a shadow under the window, or apply translucency when moving it, and generally doesn't seem to treat VLC as a normal window. The current handling deviates from how other windows behave (no shadows, no translucency when moving the window, snap-to-borders doesn't work the same way as other KDE windows, etc.)

On the VLC forums, I was told that this is because VLC is not a KDE application, and later that I should tell the KWin devs about it. (Forum post: http://forum.videolan.org/viewtopic.php?f=13&t=80400)

Reproducible: Always

Steps to Reproduce:
Start VLC in skins mode.

Comment 1 Thomas Lübking 2010-08-02 00:17:41 UTC

vlc's skinned interface uses shaped ARGB windows that would require (have a look at eg. the PSP skin) shaped shadows (ie. copying and blurring the windows alpha mask) what is not supported (so far?!?) and would pot. lead to conflicts with other windows sharing these attributes and painting their "own shadows".
(aside being pretty slow)

if you use a nearby rectangular skin you can use this "fork" http://kde-look.org/content/show.php?content=121607 and set a property to force shadow painting nevertheless, scripted like

#!/bin/sh
/usr/bin/vlc & # launch vlc
sleep 5 # sleep 5 seconds to ensure vlc has started and the windows are mapped
#grep the WId's
vlc_ids=$(xwininfo -root -int -tree | grep vlc | sed -e 's/^ *\([^ ]*\).*$/\1/g')
#set properties for all id's
for id in $vlc_ids; do 
   xprop -id $id -f _KDE_SHADOW_FORCE 32a -set _KDE_SHADOW_FORCE 1
done

but i'd recommand to use the Qt interface for performance reasons - esp. with enabled compositing

Comment 2 Thomas Lübking 2010-08-02 00:19:13 UTC

ps: stuff like wobbly windows et. al won't work since skinned vlc tries to act as WM by itself what prevents several state (moving etc.) interceptions - this won't fix.

Comment 3 Martin Flöser 2010-08-02 17:33:23 UTC

This is a bug in vlc. As vlc tries to be smart (moving window by itself, etc.) it is completely bypassing the window manager which causes problems as seen here in this bug report.

You can find a more complete list of the problems which are caused by applications like vlc in my blog post: http://blog.martin-graesslin.com/blog/2010/05/open-letter-the-issues-with-client-side-window-decorations/

Feel free to forward this information to VLC - they really should change this behavior. It's completely broken and there is no reason to do it.