Bug 450658

Summary:	Dark theme is unusable
Product:	[Applications] plasma-systemmonitor	Reporter:	kde
Component:	general	Assignee:	KSysGuard Developers <ksysguard-bugs>
Status:	RESOLVED NOT A BUG
Severity:	normal	CC:	ahiemstra, essin, kde, nate, nicolas.fella, plasma-bugs-null
Priority:	NOR
Version First Reported In:	5.24.1
Target Milestone:	---
Platform:	Ubuntu
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	Screenshot of System Monitor with dark theme

Description kde 2022-02-21 16:10:20 UTC

SUMMARY
When using a dark theme the text does not change to use a light font color, leaving black text on a dark/black background which is very difficult to read (if not completely impossible).


STEPS TO REPRODUCE
1. In Settings, set the global theme to a dark theme (e.g. Breeze Dark).
2. Open System Monitor
3. Try to read any text/graphs/etc.

OBSERVED RESULT
The text is black on a dark background and therefore unreadable.

EXPECTED RESULT
The text should be white/light colored and easily readable on the dark background.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 5.13.0-28-generic
KDE Plasma Version: 5.24.1
KDE Frameworks Version: 5.91.0
Qt Version: 5.15.2

Comment 1 Nicolas Fella 2022-02-21 23:32:28 UTC

Can you please show a screenshot of the problem?

Comment 2 kde 2022-02-22 14:27:50 UTC

Created attachment 147050 [details]
Screenshot of System Monitor with dark theme

Comment 3 Arjen Hiemstra 2022-02-22 15:22:05 UTC

Which Qt Widgets style and QtQuick Controls style are you using? That does not look like default Breeze.

Comment 4 kde 2022-02-22 15:27:18 UTC

I am not sure where to find those settings?

Comment 5 Arjen Hiemstra 2022-02-22 16:33:51 UTC

The widget style is listed in the "Application Style" page in System Settings. If you've not done anything special, the Qt Quick Controls style should be the default, which is the KDE QtQuick Controls 2 Desktop style.

Comment 6 kde 2022-02-22 17:03:07 UTC

"Application Style" shows Breeze as the selected option, and I don't know where to change the Qt Quick Controls style settings so I guess it's the default?

Comment 7 Nate Graham 2022-02-22 17:12:11 UTC

You are probably missing the qqc2-desktop-style package. I don't know what it's named in Ubuntu-based distros, but if you search for "qqc2" you might find it. Can you see if it's missing, and if so install it, and see if that fixes the issue?

Comment 8 kde 2022-02-22 17:15:52 UTC

Actually, it appears to be caused by having set QT_QPA_PLATFORMTHEME in my ~/.profile. I removed it and restarted and everything looks normal now

Comment 9 Dan 2023-01-18 17:46:18 UTC

I have checked all of the above suggestions. I have no .profile. qqc2-desktop-style is installed. I have tried all of the available "light" theme variations that are shown on the  "Application Style" page in System Settings. None of them affect the appearance of the plasma system monitor it's still black (dark blue?) text on a black background. Totally unusable. Why isn't there a settings option within the app to set or override the theme?

As it is it is totally useless

Comment 10 Nate Graham 2023-01-18 19:49:47 UTC

Dan, your issue is probably caused by a different proximate cause, but the result is the same: something in your environment is preventing the default qqc2-desktop-style theme from loading. You'll have to do some troubleshooting to figure out what that is. Perhaps ask for help in a distro-specific forum.