Bug 425959

Summary:	Dark Themes do not display text correctly
Product:	[Applications] kid3	Reporter:	Dan <dan>
Component:	general	Assignee:	Urs Fleisch <ufleisch>
Status:	RESOLVED NOT A BUG
Severity:	normal	CC:	tukusejssirs
Priority:	NOR
Version First Reported In:	unspecified
Target Milestone:	---
Platform:	Mint (Ubuntu based)
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Dan 2020-08-29 21:04:11 UTC

SUMMARY


STEPS TO REPRODUCE
1. Set Theme on PC to Controls/Mint-Y-Dark
2. In Kid3 QT use Setting/sAppearence untick Use Custom Application Style
3. Restart Kid3 QT

OBSERVED RESULT
Tool bar has wrong icons and any text in the Tag boxes does not display correctly once you try to make an amendment.

EXPECTED RESULT
The Dark theme should work and there should be no difficulty reading amended text in the Tag fileds

SOFTWARE/OS VERSIONS

Linux Min 20.0
(available in About System)
KDE Plasma Version: n/a
KDE Frameworks Version: n/a 
Qt Version: 5.12.8.

ADDITIONAL INFORMATION

If you instead use a Dark Custom theme from Kid3 QT selection, the same effect can be observed

Comment 1 Urs Fleisch 2020-08-30 14:02:05 UTC

Use qt5ct (it is already installed in Linux Mint, and the environment variable QT_QPA_PLATFORMTHEME=qt5ct is set correctly). You can set the icon theme to "Mint-Y-Dark" there and eventually also adapt other settings. This should fix the issue with the wrong icons.

The strange behavior when replacing text inside the frame table is probably a bug of a Qt style plugin. Kid3 uses plain Qt widgets. I found the following workaround: You can select any of the qss files (e.g. "fusion-fixes.qss") in the "Style Sheets" tab of qt5ct.

Comment 2 Dan 2020-08-30 14:49:11 UTC

Using QT Settings and using fusion-fixes.qss perfectly solves the text entry issue.

However, I cannot restore the icons in the toolbar. Using the Kid3 System default for appearence, shows the dark them I am using, i.e. Mint-y-Dark. The icons are set to Mint-X-Dark. - Changing to the qt5ct style sheet, does not have any effect on the toolbar. 

How do I ensure QT_QPA_PLATFORMTHEME=qt5ct is set properly?

Comment 3 Urs Fleisch 2020-08-30 17:04:24 UTC

In my installation, selecting "Mint-Y-Dark" in the "Icon Theme" tab of the "Qt5 Configuration Tool" and then clicking "Apply" has an immediate effect on the icons in the toolbar of kid3-qt.

Ensuring that QT_QPA_PLATFORMTHEME=qt5ct is set properly can be made in the terminal

$ env | grep QT_QPA_PLATFORMTHEME
QT_QPA_PLATFORMTHEME=qt5ct

It seems to be set in /etc/X11/Xsession.d/99qt5ct (unless your desktop is KDE).

Comment 4 tukusejssirs 2020-10-19 11:10:34 UTC

Sorry for being a bit OT, but I have no idea how to change the theme to dark theme in Kid3 3.8.4 (installed using `dnf`) on Fedora 32 x86_64 using SwayWM.

I thought there would be a preference in Kid3 configurations, but there is not such setting. Also there is no `Appearance` item in the `Settings` menu (there are only the following configuration items: `Configure Keyboard Shortcuts`; `Configure Toolbars`; and `Configure Kid3`).

Should I rather build Kid3 from the sources?

Thanks for the answer.

Comment 5 Urs Fleisch 2020-10-19 17:54:06 UTC

> I have no idea how to change the theme to dark theme

If you are using KDE, you could simply change "Workspace Theme/Look And Feel" to "Breeze Dark".
But probably, your desktop is not KDE. The styles available in the settings (Appearance/Use custom application style) are only those built into Qt. To have more styles available, you could install qt5ct and set the environment variable QT_QPA_PLATFORMTHEME=qt5ct. Maybe you can set a dark theme in qt5ct.
Another possibility could be to use QGtkStyle and use a dark GTK style.