Bug 493066

Summary:	Add the ability to choose which display's brightness level should be controlled by keyboard shortcuts
Product:	[Plasma] plasmashell	Reporter:	Dmitrii Chermnykh <chermnykh2001>
Component:	Power management & brightness	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED INTENTIONAL
Severity:	wishlist	CC:	chermnykh2001, jpetso, natalie_clarius, nate
Priority:	NOR
Version First Reported In:	6.2.4
Target Milestone:	1.0
Platform:	NixOS
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Dmitrii Chermnykh 2024-09-13 16:04:30 UTC

SUMMARY
Currently pressing keyboard shortcuts changes the brightness level for for all displays available in the system simultaneously. It may not be a good idea since every display's brightness range is different, causing the perceived brightness to be different after pressing the shortcuts

STEPS TO REPRODUCE
1. Use multiple displays
2. Adjust brightness via keyboard shortcuts

OBSERVED RESULT
The brightness level is changed for all displays in the system causing the perceived brightness level to be different for each display

EXPECTED RESULT
I don't know which option would be better from UX point of view, here are my proposals:
- Ability to choose which display's brightness is controlled: the active screen (the screen that was the last one to receive user input), both screens, only one screen (picked by the user)
- Somehow equalize the perceived brightness level of all displays (maybe it's possible with the reported HW capabilities and/or using the provided ICC profiles) 

SOFTWARE/OS VERSIONS
Operating System: NixOS 24.11
KDE Plasma Version: 6.1.90 (built from https://github.com/NixOS/nixpkgs/pull/341487)
KDE Frameworks Version: 6.5.0
Qt Version: 6.7.2
Kernel Version: 6.10.9-zen1 (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 5800H with Radeon Graphics
Memory: 23.3 GiB of RAM
Graphics Processor: NVIDIA GeForce RTX 3050 Ti Laptop GPU/PCIe/SSE2

ADDITIONAL INFORMATION
qdbus org.kde.Solid.PowerManagement /org/kde/ScreenBrightness/display0 org.kde.ScreenBrightness.Display.IsInternal
true

qdbus org.kde.Solid.PowerManagement /org/kde/ScreenBrightness/display0 org.kde.ScreenBrightness.Display.MaxBrightness
10000

qdbus org.kde.Solid.PowerManagement /org/kde/ScreenBrightness/display1 org.kde.ScreenBrightness.Display.IsInternal
false

qdbus org.kde.Solid.PowerManagement /org/kde/ScreenBrightness/display1 org.kde.ScreenBrightness.Display.MaxBrightness
10000

Comment 1 Nate Graham 2024-09-17 21:30:49 UTC

Relative brightness differences can be harmonized by changing the brighter display's brightness to match that of the dimmer one. Thereafter, invoking the global brightness actions will preserve the gap in their brightnesses when brightening or dimming them.

I'm not sure if what you propose would be an improvement over this; it seems like it would add more complexity and introduce the potential for confusion and bugs.

What do you think, Jakob?

Comment 2 Nate Graham 2025-06-04 19:53:08 UTC

No response; assuming no interest in doing this, so marking it as RESOLVED INTENTIONAL.