Bug 477680 - Selecting a primary monitor in a multiple monitor setup enables the wrong monitor
Summary: Selecting a primary monitor in a multiple monitor setup enables the wrong mon...
Status: RESOLVED NOT A BUG
Alias: None
Product: systemsettings
Classification: Applications
Component: kcm_kscreen (show other bugs)
Version: 5.27.80
Platform: Other Linux
: NOR normal
Target Milestone: ---
Assignee: kscreen-bugs-null@kde.org
URL:
Keywords: qt6
Depends on:
Blocks:
 
Reported: 2023-11-28 16:42 UTC by cookiesandcream
Modified: 2023-11-29 17:59 UTC (History)
2 users (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


Attachments
As can be seen in the screenshot, the right monitor is selected as primary despite the left one having the default panel there (2.03 MB, image/png)
2023-11-28 16:43 UTC, cookiesandcream
Details

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Description cookiesandcream 2023-11-28 16:42:10 UTC
SUMMARY
***
When I go to system settings and try to set my left monitor as the primary one, it sets my right one as primary. And same vice-versa. 
***


STEPS TO REPRODUCE
1. Open system settings and go to display configuration section
2. Make a monitor primary
3. Observe the other monitor becoming the primary one

OBSERVED RESULT
The other monitor becomes the primary monitor despite it saying otherwise in system settings

EXPECTED RESULT
The monitor I clicked primary on becomes the primary monitor

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Fedora 40 Kinoite Rawhide w/ plasma 6 nightly images
(available in About System)
KDE Plasma Version: 5.27.80
KDE Frameworks Version: 5.245.0
Qt Version: 6.6.0

ADDITIONAL INFORMATION
I use AMD gpu on wayland if that matters
Comment 1 cookiesandcream 2023-11-28 16:43:20 UTC
Created attachment 163581 [details]
As can be seen in the screenshot, the right monitor is selected as primary despite the left one having the default panel there
Comment 2 Nate Graham 2023-11-28 20:57:49 UTC
When you say "Observe the other monitor becoming the primary one" is this observation based on seeing which monitor as your panel on it? If so, that's not quite how it works. Changing the primary monitor simply moves your primary Plasma desktop/containment there. However if that desktop/containment does not have a panel on it, then when a monitor becomes primary, that monitor won't have a panel on it.

Can you move your panel to the desired monitor, and then change which one is primary, and see if the issue is fixed?
Comment 3 cookiesandcream 2023-11-29 05:13:00 UTC
(In reply to Nate Graham from comment #2)
> When you say "Observe the other monitor becoming the primary one" is this
> observation based on seeing which monitor as your panel on it? If so, that's
> not quite how it works. Changing the primary monitor simply moves your
> primary Plasma desktop/containment there. However if that
> desktop/containment does not have a panel on it, then when a monitor becomes
> primary, that monitor won't have a panel on it.
> 
> Can you move your panel to the desired monitor, and then change which one is
> primary, and see if the issue is fixed?

You are right that I was trying to judge which monitor was primary based on the panel location. I tried moving the panel as you mentioned, and now the panel moves to the left monitor when it is selected as primary as expected. There is still confusing behavior where if I click one of the arrows after 'set position' on the second monitor, the panel moves to the corresponding position on the other monitor. I was able to move it with "manage desktops and panels" though. Is that something I should file a bug about?
Comment 4 cookiesandcream 2023-11-29 05:13:48 UTC
I will also add that I was confused about this behavior because I have never encountered this on plasma 5, and this is a fresh /home on plasma 6 which is why i thought it was a bug. Thanks for the help :)
Comment 5 Nate Graham 2023-11-29 17:59:07 UTC
Cool, sounds like there's no bug to fix here. The issue with the arrows was an unrelated multiscreen panel positioning bug which has since been fixed.