Bug 164501 - KDE Plasma 6, UI elements too small specifically at 125% display scaling, fixed with SAL_FORCEDPI=175
Summary: KDE Plasma 6, UI elements too small specifically at 125% display scaling, fix...
Status: RESOLVED WORKSFORME
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: UI (show other bugs)
Version:
(earliest affected)
24.2.7.2 release
Hardware: x86-64 (AMD64) Linux (All)
: medium normal
Assignee: Not Assigned
URL:
Whiteboard:
Keywords:
Depends on:
Blocks: HiDPI Wayland Qt6
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Reported: 2024-12-28 10:57 UTC by Nefas
Modified: 2025-01-10 19:12 UTC (History)
1 user (show)

See Also:
Crash report or crash signature:


Attachments
Screens setup (194.55 KB, image/png)
2025-01-10 15:43 UTC, Nefas
Details

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Description Nefas 2024-12-28 10:57:39 UTC
Description:
LibreOffice UI elements appear too small when using KDE Plasma 6 with 125% display scaling. This affects all LibreOffice applications and can be worked around by setting SAL_FORCEDPI=175.

Steps to Reproduce:
1. Fresh installation of LibreOffice on EndeavourOS with KDE Plasma 6
2. Set display scaling to 125% in KDE System Settings
3. Open any LibreOffice application

Actual Results:
UI elements (menus, toolbars, icons) appear too small, not respecting the system's 125% scaling setting.

Expected Results:
UI elements should scale properly according to the system's 125% scaling setting.


Reproducible: Always


User Profile Reset: Yes

Additional Info:
Environment:
- LibreOffice Version: 24.2.7.2 (X86_64) / LibreOffice Community
- Build ID: 420(Build:2)
- OS: EndeavourOS (Kernel 6.6.67-1-lts)
- Desktop Environment: KDE Plasma 6
- Display: 2560x1440 with 125% scaling
- VCL: kf6 (cairo+wayland)

- Issue occurs specifically at 125% scaling
- Problem affects all LibreOffice applications
- Issue persists in safe mode
- Resetting UserProfile does not resolve the issue
- Problem persists across both still and fresh versions
- System is using Wayland display server

Workaround:
Setting the environment variable SAL_FORCEDPI=175 resolves the issue.
Comment 1 Michael Weghorn 2025-01-10 13:36:58 UTC
I can't reproduce on Debian testing (in a self-built Plasma Dev Wayland session). The UI is scaled, i.e. is larger with 125% than with 100%.

Questions:

1) Is that in a single-screen setup?
2) Is the UI the same as when using 100% scaling for you or what's the unexpected behavior in more detail?
3) If answer to 2) is no: Can you attach screenshots for both cases?
Comment 2 Michael Weghorn 2025-01-10 13:38:34 UTC
(In reply to Michael Weghorn from comment #1)
> I can't reproduce on Debian testing (in a self-built Plasma Dev Wayland
> session). The UI is scaled, i.e. is larger with 125% than with 100%.

Version I used:

Version: 25.8.0.0.alpha0+ (X86_64) / LibreOffice Community
Build ID: 61cb7921a09cffb4f95b36985ecd8acc083b8138
CPU threads: 32; OS: Linux 6.12; UI render: default; VCL: qt6 (cairo+wayland)
Locale: en-GB (en_GB.UTF-8); UI: en-US
Calc: threaded
Comment 3 Nefas 2025-01-10 15:43:58 UTC
Created attachment 198472 [details]
Screens setup

My monitor setup, dual-monitor with main screen set to 125% scaling and second monitor at 100% scaling and vertical layout.
Comment 4 Nefas 2025-01-10 15:51:00 UTC
(In reply to Michael Weghorn from comment #1)
> I can't reproduce on Debian testing (in a self-built Plasma Dev Wayland
> session). The UI is scaled, i.e. is larger with 125% than with 100%.
> 
> Questions:
> 
> 1) Is that in a single-screen setup?
> 2) Is the UI the same as when using 100% scaling for you or what's the
> unexpected behavior in more detail?
> 3) If answer to 2) is no: Can you attach screenshots for both cases?

Hey Michael, it's been some time since I've last used a LibreOffice application, and I can't seem to be able to reproduce the issue anymore either. I must've updated LibreOffice or installed some package that fixed the issue, the most notable packages I installed are the ones from the libvirt Arch Linux wiki page.

I believe the ticket can be safely closed and disregarded as a missing library causing havoc, regardless, thank you for your intervention and work.
Comment 5 Michael Weghorn 2025-01-10 19:12:32 UTC
(In reply to Nefas from comment #3)
> My monitor setup, dual-monitor with main screen set to 125% scaling and
> second monitor at 100% scaling and vertical layout.

Multi-screen setups with different scaling factors for the individual screens are known to be somewhat problematic, see also tdf#141578 for more details, but the SAL_FORCEDPI workaround should be a workable solution for now at least in case you ever encounter this again before tdf#141578 gets fixed.

(In reply to Nefas from comment #4)
> I believe the ticket can be safely closed and disregarded as a missing
> library causing havoc, regardless, thank you for your intervention and work.

Thanks for the feedback. I'm closing this accordingly for now.