Can not disable shadows in Window Decoration

[A. Bram Neijt]

Binary package hint: compiz

Using the CompizConfig Setings Manager it is impossible to disable shadows using the Shadow windows configuration. The default value is "any" but changing this to anything else does not have any effect on the visibility of window shadows. Turning shadows off is therefore impossible.

The documentation suggests[1] an empty field, which does not work. Inventive other things like "!any" and "title=Calculator" do not have any effect either.

To reproduce the bug:
1) Install and open ccsm
2) Go to the Window Decoration plugin
3) Change the default value of "any" in the bottom field (Shadow windows) to anything else

What happens:
Nothing, I would expect it to have some kind of immediate effect just like with the Decoration Windows field. Rebooting (full restart) does not help.

Expected behavior: Either the shadows of some windows would disappear.

[1] http://wiki.compiz.org/WindowMatching

ProblemType: Bug
Architecture: amd64
CompizPlugins: [core,ccp,move,resize,place,decoration,imgjpeg,staticswitcher,svg,commands,dbus,gnomecompat,text,session,png,workarounds,regex,scale,glib,vpswitch,wall,expo,resizeinfo,scaleaddon,snap]
Date: Wed Jan 6 14:40:11 2010
DistroRelease: Ubuntu 10.04
EcryptfsInUse: Yes
ExecutablePath: /usr/bin/compiz
InstallationMedia: Ubuntu 10.04 "Lucid Lynx" - Alpha amd64 (20091209)
MachineType: LENOVO 64669MG
Package: compiz-core 1:0.8.4-0ubuntu9
PccardctlIdent:
 Socket 0:
   no product info available
PccardctlStatus:
 Socket 0:
   no card
PciDisplay: 00:02.0 VGA compatible controller [0300]: Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller [8086:2a02] (rev 0c)
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.32-7-generic root=UUID=6a56c236-560b-43fb-b0e4-378b524a3029 ro quiet splash
ProcEnviron:
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.32-7.10-generic
RelatedPackageVersions:
 xserver-xorg 1:7.5~3ubuntu2
 libgl1-mesa-glx 7.6.1~rc2-1ubuntu1
 libdrm2 2.4.14-1ubuntu1
 xserver-xorg-video-intel 2:2.9.1-1ubuntu1
 xserver-xorg-video-ati 1:6.12.99+git20090929.7968e1fb-0ubuntu2
SourcePackage: compiz
Tags: lucid
Uname: Linux 2.6.32-7-generic x86_64
XorgConf: Error: [Errno 2] No such file or directory: '/etc/X11/xorg.conf'
dmi.bios.date: 07/01/2008
dmi.bios.vendor: LENOVO
dmi.bios.version: 7LETC1WW (2.21 )
dmi.board.name: 64669MG
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr7LETC1WW(2.21):bd07/01/2008:svnLENOVO:pn64669MG:pvrThinkPadT61:rvnLENOVO:rn64669MG:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 64669MG
dmi.product.version: ThinkPad T61
dmi.sys.vendor: LENOVO
glxinfo: Error: [Errno 2] No such file or directory
system: distro = Ubuntu, architecture = x86_64, kernel = 2.6.32-7-generic

[A. Bram Neijt (bneijt)]

I've just discovered the weirdest thing, using "any & !(class=Gnome-panel)" works as expected: shadows except on the Gnome-panel. Using "any & !any" seems to have the same effect: shadows except on the Gnome-panel. "any & !class=foobar" will shows shadows everywhere "any & !(class=Gnome)" will remove shadows from the panel again.

It seems it is prefix matching as "any & !(class=Gnome-p)" will have the same effect as "any & !(class=Gnome-panel)". Why "any & !any" seems to also work is beyond me.

I have not yet found a way to disable the shadows on all windows using the Shadow windows field.

[A. Bram Neijt (bneijt)]

Reading the code [1, line 766], it seems I am just misunderstanding the option. It seems you can only disable shadows on windows which have no decoration in the first place. Hence the shadow on the panel is effected while other shadows are not.

One bug still remains and that is that using an empty string does not reflect the behavior mentioned by the documentation (!any is different from ""). As compiz is being rewritten to C++, I'm going to try to get this bug into the won't fix.

Any other users out there trying to get rid of shadows: use an extremely low opacity and radius as a work-around.

[1] http://gitweb.compiz.org/?p=compiz/core;a=blob;f=plugins/decoration.c;h=89e71060ac0143d9f224ac30c895bf72208f52d9;hb=03ae274cc3bfb191734881017f7b0cf7b9234abe

[A. Bram Neijt (bneijt)]

I consider this a "Won't fix" as Compiz is being rewritten in C++. The option is unclear about only applying to windows without a decoration, it's description and form will have to be evaluated with the next Compiz release.