Bug 469343

Summary:	Prevent multiple monitors displaying the same slideshow-based wallpaper at the same time
Product:	[Plasma] plasmashell	Reporter:	Quenten <personal>
Component:	Image & Slideshow wallpaper plugins	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	CONFIRMED ---
Severity:	wishlist	CC:	nate, notmart, qydwhotmail
Priority:	NOR
Version First Reported In:	5.27.4
Target Milestone:	1.0
Platform:	Arch Linux
OS:	Linux
See Also:	https://bugs.kde.org/show_bug.cgi?id=482542
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Quenten 2023-05-04 08:33:06 UTC

SUMMARY
I have multiple monitors on my setup and I have the wallpapers on each one set to "slideshow" with the "random" order. All of these have the same directory set as the source and the same interval. Because of the random nature of the slideshows, it's possible for two monitors to show the same wallpaper at the same time. Can this be fixed?

STEPS TO REPRODUCE
1. Have multiple monitors on your computer
2. On two or more monitors, set up a random-order wallpaper slideshow of the same directory or at least containing the same wallpapers 
3. Wait, due to the random nature of the slideshow, it's possible to show the same wallpaper.

OBSERVED RESULT
The same wallpaper may be shown on multiple monitors.

EXPECTED RESULT
The same wallpaper may not appear on two monitors at the same time. 

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 6.1.24-1-lts
(available in About System)
KDE Plasma Version: 5.27.4
KDE Frameworks Version: 5.105.0
Qt Version: 5.15.9

ADDITIONAL INFORMATION
This is a pretty show priority request, I understand that completely. If my math is right, then if I have 10 wallpapers in the set and two monitors, then the probability that both monitors display the same wallpaper is 10%, so only 10% of the time that I am looking at my desktop wallpaper I can even notice this issue. So consider it not very high on the priority list, hence the minor status of this bug report.

Comment 1 Nate Graham 2023-05-15 21:07:31 UTC

Anything is possible in theory, but yeah, I suspect the effort-to-reward radio here might not be very high.

Fushan, what do you think, can we do this easily? If not, I'd suggest closing it.

Comment 2 Fushan Wen 2023-05-16 00:54:55 UTC

I asked GPT and it provides a method that should be no that hard to implement. Will look into it when I am not too busy.

Comment 3 Fushan Wen 2023-05-27 16:39:51 UTC

The problem is that not all slideshow plugins will have the same directories, so I am not sure it can be fixed without adding too much code.