Bug 482586

Summary:	Cursor size is inconsistent when switching between Wayland and X11
Product:	[Applications] systemsettings	Reporter:	daf <daf.public>
Component:	kcm_cursortheme	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED NOT A BUG
Severity:	normal	CC:	nate
Priority:	NOR	Keywords:	qt6
Version First Reported In:	6.0.1
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description daf 2024-03-06 20:58:28 UTC

SUMMARY

On Wayland cursor size are 2x the size then they are on X11 for any given picked size. 

STEPS TO REPRODUCE
1. Select a big cursor size in X11
2. Change to a Wayland session


OBSERVED RESULT

Cursor now looks 2x bigger then it did on X11

EXPECTED RESULT

Cursor size should be consistent across Wayland and X11

SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 6.0.1
KDE Frameworks Version: 6.0.0
Qt Version: 6.6.2
Kernel Version: 6.7.8-arch1-1 (64-bit)
Graphics Platform: X11
Processors: 32 × AMD Ryzen 9 5950X 16-Core Processor
Memory: 62.7 GiB of RAM
Graphics Processor: AMD Radeon RX 7900 XTX
Manufacturer: Gigabyte Technology Co., Ltd.
Product Name: X570 AORUS ELITE
System Version: -CF

ADDITIONAL INFORMATION

Comment 1 Nate Graham 2024-03-07 17:22:19 UTC

Right, the X11 cursor size was always wrong. It's correct on Wayland. :)

Comment 2 daf 2024-03-07 23:20:55 UTC

Panel sizing was made the same on Wayland and X11, should cursor size in the settings also be adjusted so it's seamless transition?

Comment 3 Nate Graham 2024-03-08 21:22:18 UTC

It's not really that easy... On X11 the unscaled cursors are an X server bug that we can't really fix in KWin. The most we could do is replicate that bug on Wayland, but hauling forward old bugs forever in the name of consistency isn't really amazing either.

Comment 4 daf 2024-03-09 11:14:48 UTC

(In reply to Nate Graham from comment #3)
> It's not really that easy... On X11 the unscaled cursors are an X server bug
> that we can't really fix in KWin. The most we could do is replicate that bug
> on Wayland, but hauling forward old bugs forever in the name of consistency
> isn't really amazing either.

Maybe I'm over simplifying the problem but wouldn't it be easier to simply use the Wayland value in the settings and adjust the actual configured cursor size on X11? 

Example: set size 48
Wayland gets set to size 48
X11 gets set closest size of 48 * scaling factor

So Wayland works ass intended and only X11 gets a workaround.

Cursor changes don't apply instantly, so when changing session I need to fix the cursor size and then restart to ensure the cursor size is applied to everything which makes swapping sessions more annoying then a dual boot situation with different settings.

Panel size used to also have the exact same problem and now in plasma 6 it doesn't, so the cursor sticks out as the only thing that isn't consistent.