Bug 503186 - Zoom: cursor is not aligned with clicks when zoom mouse settings are push/keep and proportional/centered
Summary: Zoom: cursor is not aligned with clicks when zoom mouse settings are push/ke...
Status: CONFIRMED
Alias: None
Product: kwin
Classification: Plasma
Component: effects-various (other bugs)
Version First Reported In: 6.3.4
Platform: Fedora RPMs Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords: accessibility
: 503198 (view as bug list)
Depends on:
Blocks:
 
Reported: 2025-04-22 17:50 UTC by cskurk123
Modified: 2025-04-28 16:31 UTC (History)
4 users (show)

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


Attachments
Screenshot of Bugzilla bug submission form. Mouse is hovering over blue of "submit bug" button but the color picker chooses the white background of the page. (976.55 KB, image/png)
2025-04-22 17:50 UTC, cskurk123
Details
Double cursor with I beam and pointer (148.79 KB, image/jpeg)
2025-04-23 20:56 UTC, TraceyC
Details

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Description cskurk123 2025-04-22 17:50:47 UTC
Created attachment 180531 [details]
Screenshot of Bugzilla bug submission form. Mouse is hovering over blue of "submit bug" button but the color picker chooses the white background of the page.

SUMMARY
When the zoom effect is enabled color pickers such as Kcolorchooser or Eyedropper select a color below the highlighted pixel gets chosen. Depending on the severity of the zoom it picks one further down. I tested this with both the RPM and Flatpaks of both color pickers.

STEPS TO REPRODUCE
1.  Zoom in with push or centered settings
2. Select a color 

OBSERVED RESULT
A color a few pixels below the highlighted one gets chosen 

EXPECTED RESULT
Color gets picked

SOFTWARE/OS VERSIONS
Linux: 6.14 (Nobara 41)
KDE Plasma Version: 6.4.3
KDE Frameworks Version: 6.13.0
Qt Version: 6.8.2
Comment 1 TraceyC 2025-04-22 19:39:21 UTC
Thanks for the bug report and the screenshot. I can see the problem you see.

I wasn't able to reproduce this on git-master using KColorChooser with
- Zooming the browser
- Zooming in on the desktop

When you say
1.  Zoom in with push or centered settings

What exactly are you zooming, and what are you doing exactly to zoom in?
Thanks
Comment 2 cskurk123 2025-04-22 22:00:29 UTC
(In reply to TraceyC from comment #1)
I mean zooming with the KDE Plasma zoom effect with Ctrl+Meta+Scroll. By push and center settings I mean the mouse tracking setting in the zoom desktop effect configuration. Sorry for the confusion.

After further testing it's easier to reproduce after switching the mouse pointer setting from scale to keep while zoomed in and changing it to scale at the normal size. Changing the mouse tracking at the original size from centered to proportional creates a second cursor when zooming with the keep mouse pointer setting. It disappears after changing the mouse tracking, but now it's always there on proportional with the keep mouse pointer option.

The color picker issue always persists when zoomed in except when there are 2 cursors with proportional and the keep mouse pointer option.

It seems to happen now with all the mouse tracking settings but at first it only happened on push and centered when I didn't mess much with the settings.
Comment 3 TraceyC 2025-04-23 20:53:13 UTC
Thanks for clarifying. We got another report of this, and I was able to reproduce the problem.
Comment 4 TraceyC 2025-04-23 20:53:54 UTC
*** Bug 503198 has been marked as a duplicate of this bug. ***
Comment 5 TraceyC 2025-04-23 20:56:56 UTC
Created attachment 180589 [details]
Double cursor with I beam and pointer

While zoomed in, the actual cursor turned into an I beam in a text field. The duplicated cursor did not.
Comment 6 Ritchie Frodomar 2025-04-25 21:11:13 UTC
(In reply to TraceyC from comment #5)
> The duplicated cursor did not.

Depending on the window you were zooming into, (either running under xwayland or just a wayland client that doesn't support cursor shape protocol), this would be https://bugs.kde.org/show_bug.cgi?id=492173. If you're sure the app supports cursor shape protocol but one of the cursors still doesn't change to the I-beam, I have more questions about that bug
Comment 7 TraceyC 2025-04-28 16:19:33 UTC
(In reply to Ritchie Frodomar from comment #6)
> (In reply to TraceyC from comment #5)
> > The duplicated cursor did not.
> 
> Depending on the window you were zooming into, (either running under
> xwayland or just a wayland client that doesn't support cursor shape
> protocol), this would be https://bugs.kde.org/show_bug.cgi?id=492173. If
> you're sure the app supports cursor shape protocol but one of the cursors
> still doesn't change to the I-beam, I have more questions about that bug

In the screenshot I attached, I had zoomed in on the keyboard shortcut settings kcm
That part does sound like bug 492173