Bug 436460

Summary: Box doesn't snap correctly when monitor is mirrored
Product: [Applications] systemsettings Reporter: Chef Niko <culinaryelation>
Component: kcm_kscreenAssignee: kscreen-bugs-null <kscreen-bugs-null>
Status: RESOLVED DUPLICATE    
Severity: normal CC: culinaryelation, kde, nate, plasma-bugs
Priority: NOR    
Version: 5.21.4   
Target Milestone: ---   
Platform: Ubuntu   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:
Attachments: requested screenshot of "Display Configuration"
5.21.90 snap to 1919

Description Chef Niko 2021-05-01 16:15:08 UTC
SUMMARY
In the section "drag screens to re-arrange them" the boxes do not snap correctly when it has a replicate. It's close, but not quite accurate. This causes either a gap (offsetting full screen applications), or an overlap.

STEPS TO REPRODUCE
1. Set tertiary monitor to replicate secondary
2. Drag secondary monitor around in the "drag screens" section
3. Try to snap secondary monitor to the primary (0,1920)

OBSERVED RESULT
Inaccurate co-ordinates on snap. I've seen them in the range of 1917-1921.

EXPECTED RESULT
Accurate co-ordinates on snap. 0,1920 in my case.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Kubuntu 21.04 5.11.0-16-generic x64
KDE Plasma Version: 5.21.4
KDE Frameworks Version: 5.80.0
Qt Version: 5.15.2
Comment 1 Chef Niko 2021-05-01 16:16:34 UTC
Co-ordinates should be `1920, 0`, not `0, 1920`.
Comment 2 David Edmundson 2021-05-04 22:01:24 UTC
Please include some screenshots it is not quite clear from the description. Snapping code was changed in 5.22 so it might be worth testing against that.
Comment 3 Chef Niko 2021-05-05 01:50:11 UTC
Created attachment 138157 [details]
requested screenshot of "Display Configuration"

Sorry I wasn't more clear in the description. Here's a screenshot showing the box snapping to 1918 instead of 1920. From moving the boxes around, it seems like the edge gets offset by 1 when they stack on top of each other.

($) ~: xrandr | grep connected
DisplayPort-0 disconnected (normal left inverted right x axis y axis)
DisplayPort-1 disconnected (normal left inverted right x axis y axis)
HDMI-A-0 connected primary 1920x1080+1918+0 (normal left inverted right x axis y axis) 598mm x 336mm
HDMI-A-1 connected 1920x1080+1919+0 (normal left inverted right x axis y axis) 886mm x 498mm
DVI-D-0 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 521mm x 293mm
Comment 4 Bug Janitor Service 2021-05-20 04:33:47 UTC
Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least
15 days. Please provide the requested information as soon as
possible and set the bug status as REPORTED. Due to regular bug
tracker maintenance, if the bug is still in NEEDSINFO status with
no change in 30 days the bug will be closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

If you have already provided the requested information, please
mark the bug as REPORTED so that the KDE team knows that the bug is
ready to be confirmed.

Thank you for helping us make KDE software even better for everyone!
Comment 5 Chef Niko 2021-05-20 13:16:36 UTC
Created attachment 138611 [details]
5.21.90 snap to 1919

If you'd like me to test this against 5.22, please provide information on how to acquire 5.22 installation. I looked around online, but everything called 5.22 seems to link to 5.21.9.

I did test it against 5.21.9, and it is much better. I really like how the snap is less aggressive. Unfortunately, it's not quite right yet. Here's a screenshot from the KDE Neon 5.21.9 live image, showing the snap to 1919 instead of 1920.
Comment 6 Nate Graham 2021-05-20 16:14:51 UTC
5.21.90 is our confusing version number for the 5.22 beta. :)

Gotcha, thanks. Can confirm.
Comment 7 Nate Graham 2022-11-10 22:35:12 UTC
...And that remaining missing pixel was just fixed for Plasma 5.26.3 with the fix for Bug 455394.

*** This bug has been marked as a duplicate of bug 455394 ***