Bug 424465 - Wallpaper's open dialog's icons too small (with scaling 2.0)
Summary: Wallpaper's open dialog's icons too small (with scaling 2.0)
Status: RESOLVED DUPLICATE of bug 356446
Alias: None
Product: plasmashell
Classification: Plasma
Component: general (show other bugs)
Version: 5.22.4
Platform: Other Other
: NOR normal
Target Milestone: 1.0
Assignee: David Edmundson
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2020-07-20 13:37 UTC by postix
Modified: 2021-07-28 16:38 UTC (History)
5 users (show)

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


Attachments
Screenshot: Wallpaper "open dialog" (112.27 KB, image/png)
2020-07-20 13:37 UTC, postix
Details
Screenshot: Wallpaper "open dialog" for Okular which looks fine. (135.23 KB, image/png)
2020-07-20 13:38 UTC, postix
Details

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Description postix 2020-07-20 13:37:04 UTC
Created attachment 130283 [details]
Screenshot: Wallpaper "open dialog"

SUMMARY

While the file dialog for Okular and Kate look fine (please see the 2nd attachment), the one for the wallpapers is too tiny.


SOFTWARE/OS VERSIONS
Operating System: Manjaro Linux
KDE Plasma Version: 5.19.3
KDE Frameworks Version: 5.72.0
Qt Version: 5.15.0

ADDITIONAL INFORMATION
Scaling: 2.0
Comment 1 postix 2020-07-20 13:38:07 UTC
Created attachment 130284 [details]
Screenshot: Wallpaper "open dialog" for Okular which looks fine.
Comment 2 Nicolas Fella 2020-07-20 14:16:52 UTC
I assume you are using X11?

plasmashell (which is the process the wallpaper dialog runs in) does some unusual scaling things for reasons I don't know. 

Running plasma with PLASMA_USE_QT_SCALING=1 should fix this. There's ongoing work to enable that by default (https://invent.kde.org/plasma/plasma-workspace/-/merge_requests/139), but it's not quite there yet
Comment 3 postix 2020-07-20 14:27:56 UTC
(In reply to Nicolas Fella from comment #2)
> I assume you are using X11?

Yes

> plasmashell (which is the process the wallpaper dialog runs in) does some
> unusual scaling things for reasons I don't know. 
> Running plasma with PLASMA_USE_QT_SCALING=1 should fix this.
$ PLASMA_USE_QT_SCALING=1 plasmashell --replace

indeed fixes it. However, now my taskbar panel is twice the height (like it's when I switch from an X11 to a Wayland session).
Comment 4 Nate Graham 2020-07-23 19:04:45 UTC

*** This bug has been marked as a duplicate of bug 356446 ***
Comment 5 Nate Graham 2020-07-23 19:06:00 UTC
(In reply to Postix from comment #3)
> > plasmashell (which is the process the wallpaper dialog runs in) does some
> > unusual scaling things for reasons I don't know. 
> > Running plasma with PLASMA_USE_QT_SCALING=1 should fix this.
> $ PLASMA_USE_QT_SCALING=1 plasmashell --replace
> 
> indeed fixes it. However, now my taskbar panel is twice the height (like
> it's when I switch from an X11 to a Wayland session).
In fact it's the correct height. :) It doesn't know that you previously worked around the height being too low by doubling it manually. Once we can turn on Qt scaling by default, you won't have to do this manual step; using a high DPI scale factor will scale your panel just like you expect.
Comment 6 Nate Graham 2021-07-26 18:36:49 UTC

*** This bug has been marked as a duplicate of bug 390147 ***
Comment 7 Nate Graham 2021-07-28 15:55:19 UTC
Actually this is a separate issue. The root cause is that Plasma does not use Qt scaling by default and uses its own Plasma Scaling system to scale Plasma-drawn UI elements. However this system does not apply to Qt-drawn UI elements such as menu items, QWidgets-based dialogs, and so on. See also Bug 366088 and Bug 391682. All three of these issues may have the same root cause in the end.
Comment 8 Nate Graham 2021-07-28 16:38:24 UTC
And upon further investigation and consultation with colleagues, it is impossible to fix without turning on Qt scaling, because you can't selectively turn on or off Qt scaling for only certain UI elements. The only thing we could do is split plasmashell into multiple processes and have one process draw everything that is drawable using Plasma scaling and another process draw everything that needs to be drawn using Qt scaling. Such an endeavor would be an enormous amount of work and add substantial complexity and fragility though, so it's not really feasible.

Re-duping to Bug 356446, and I will re-open it.

*** This bug has been marked as a duplicate of bug 356446 ***