Bug 508644

Summary:	System Transparency Effects Overriding Special Application and Window Settings
Product:	[Plasma] kwin	Reporter:	kde.rescuer961
Component:	effects-various	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	CONFIRMED ---
Severity:	minor	CC:	isma.af, kdedev, nate
Priority:	NOR
Version First Reported In:	6.4.4
Target Milestone:	---
Platform:	Other
OS:	Linux
See Also:	https://bugs.kde.org/show_bug.cgi?id=483503
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description kde.rescuer961 2025-08-23 12:57:20 UTC

I have a grievance to raise with the way the window transparency rules work. I want to have VLC media player to not become transparent when I am focused on other windows so I can watch videos and type. I have my inactive windows become transparent per the system settings. So I added a rule to the special application and the special window settings to set the opacity for VLC. That doesn't work. The system settings take priority and it seems you can't turn that off as the system opacity takes priority. I turned off the system transparency and immediately the rules worked. 


STEPS TO REPRODUCE
1. Set inactive opacity to something less than 100
2. Set an application inactive opacity to 100 via "configure special application settings" or "configure special window settings


OBSERVED RESULT
The inactive window is still transparent despite telling it not to be

EXPECTED RESULT
A non-transparent inactive window

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
(available in the Info Center app, or by running `kinfo` in a terminal window)
Linux/KDE Plasma: Fedora Linux 42
KDE Plasma Version: 6.4.4
KDE Frameworks Version: 6.17.0
Qt Version: 

ADDITIONAL INFORMATION

Comment 1 TraceyC 2025-09-24 19:40:30 UTC

I'm able to reproduce this on git-master

I set the following in Application Settings for VLC
Window class - exact match - vlc
Match whole window class - no
Inactive opacity - 100

I also tried Window class - substring
The window was still translucent when inactive

This may be related to bug 483503

Comment 2 Ismael Asensio 2025-09-24 21:38:44 UTC

After some testing and a tentative fix that didn't worked, I've noticed that the opacity set by the rules and the one set by the effects are both applied at the same time (but multiplied, i.e effect 50%, rule 50% will cause a 25% opacity window). 

This means they're being applied at different layers. It also happens if one manually modifies the window opacity (via mouse scrolling action for instance) and not with rules

I'm moving the bug to the effects component, because I think the fix will have to come from a better integration between the translucent effect and the regular opacity setting mechanisms.