Issues with Kvantum correctly applying themes to QT applications

Anyone else having issues with Kvantum correctly applying themes to QT applications (e.g qBittorrent) under Gnome after this update? The dark themes apply, partially, and sections of the application windows are left white., with some text washed out and unreadable.

Downgrading the KVantum package didn’t resolve it, nor did switching to different themes. I can only presume it is an issue with one of the dependencies the package relies on, but haven’t got around to downgrading them one by one yet.

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@gqanubis @jldark With qgnomeplatform 0.7.1-1 installed, what’s the output of the following? Replace qbittorrent with another Qt app if applicable:

QT_LOGGING_RULES="qt.qpa.qgnomeplatform=true" qbittorrent
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QT_LOGGING_RULES="qt.qpa.qgnomeplatform=true" cantata                                              17:05:17
qt.qpa.qgnomeplatform: Font name:  "Noto Sans"  (size  11 )
qt.qpa.qgnomeplatform: Monospace font name:  "Noto Sans Mono Medium"  (size  11 )
qt.qpa.qgnomeplatform: TitleBar font name:  "Noto Sans"  (size  11 )
qt.qpa.qgnomeplatform: Cursor blink time:  1200
qt.qpa.qgnomeplatform: Double click time:  400
qt.qpa.qgnomeplatform: Long press time:  500
qt.qpa.qgnomeplatform: Double click distance:  5
qt.qpa.qgnomeplatform: Dnd drag threshold:  8
qt.qpa.qgnomeplatform: Password hint timeout:  0
qt.qpa.qgnomeplatform: Icon theme:  "Papirus-Dark"
qt.qpa.qgnomeplatform: Theme name:  "kvantum"
qt.qpa.qgnomeplatform: Dark version:  no

So, where can I set Dark version to true ?

It’s not detecting your Kvantum theme, what theme did you choose in Kvantum Manager?

It detects whether the Kvantum theme is a dark version or not. Example:

qt.qpa.qgnomeplatform: Theme name:  "Adwaita-maia-dark"
qt.qpa.qgnomeplatform: Dark version:  yes

Whatever the theme I use, it always returns “kvantum” (that was not the case with the previous version of qgnomeplatform), despite it’s correctly set in kvantum config :

cat kvantum.kvconfig:

[General]
theme=KvAdaptaMaiaBlack

I got the same issue. I had to downgrade qgnomeplatform from 0.7.1-1 to 0.7.0-1 to solve.

Oops, missed a post when I moved them to this topic, so one is out of order.

What GTK / GNOME Shell theme are you using?

What’s the output of:

cat /etc/environment

And if it exists:

cat ~/.profile

When pasting terminal output, highlight it and use the Preformatted text </> button.

Alternatively, add three backticks ` above and below the text:

```
text
```

/etc/environment :
#
# This file is parsed by pam_env module
#
# Syntax: simple “KEY=VAL” pairs on separate lines
#
CALIBRE_USE_DARK_PALETTE=1
QT_QPA_PLATFORMTHEME=“gnome”
QT_STYLE_OVERRIDE=“kvantum”
QT_AUTO_SCREEN_SCALE_FACTOR=1

Note :
Trying to override style I got this error :
Available styles: Adwaita-Dark, Adwaita, kvantum-dark, kvantum, Windows, Fusion
I set QT_STYLE_OVERRIDE to kvantum-dark and now evrything is fine … at least with dark theme

qt.qpa.qgnomeplatform: Icon theme: “Papirus-Dark”
qt.qpa.qgnomeplatform: Theme name: “kvantum-dark”
qt.qpa.qgnomeplatform: Dark version: yes

So it seems that the real Kvantum theme is not fully taken into account as it was the case in the previous version where I got the real theme name and not “kvantum-dark”

My output is:

/etc/environment                                           
#
# This file is parsed by pam_env module
#
# Syntax: simple "KEY=VAL" pairs on separate lines
#

QT_AUTO_SCREEN_SCALE_FACTOR=1

QT_QPA_PLATFORMTHEME="gnome"

QT_STYLE_OVERRIDE="kvantum"

# Force to use Xwayland backend
# QT_QPA_PLATFORM=xcb

#Not tested: this should disable window decorations
# QT_WAYLAND_DISABLE_WINDOWDECORATION=1

EDITOR=/usr/bin/nano

.profile                                                    
export EDITOR=/usr/bin/nano
export QT_QPA_PLATFORMTHEME="gnome"
export QT_AUTO_SCREEN_SCALE_FACTOR=0
export GTK2_RC_FILES="$HOME/.gtkrc-2.0"
export QT_STYLE_OVERRIDE="kvantum"

Interestingly, if I install the qt5ct package, then Kvantum themes start correctly applying.

Edit: I can also confirm that downgrading qgnomeplatform from 0.7.1-1 to 0.7.0-1 resolves the issue for me, without the need to have qt5ct installed.

What GTK theme are you guys using? Can you reproduce it with Adwaita-dark or Adwaita-maia-dark?

QGnomePlatform checks if the theme name has “-dark” in the name.

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I tested with gtk theme Adwaita-blue-dark

With the last qgnomeplatform I get :
qt.qpa.qgnomeplatform: Icon theme: “Papirus-Dark”
qt.qpa.qgnomeplatform: Theme name: “kvantum-dark” (QT_STYLE_OVERRIDE)

With the previous qgnomeplatform :
qt.qpa.qgnomeplatform: Icon theme: “Papirus-Dark”
qt.qpa.qgnomeplatform: Theme name: “Adwaita-blue-dark” (gtk theme used)

So qgnomeplatform in its last version doesn’t check the real gtk theme name but seems to fallback to the value of QT_STYLE_OVERRIDE that’s why dark theme are "OK " when I set it to kvantum-dark

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Hmm… it seems to be due to this commit:

Ok I had a look at the code
If I unset QT_STYLE_OVERRIDE gtk theme is used :
qt.qpa.qgnomeplatform: Icon theme: “Papirus-Dark”
qt.qpa.qgnomeplatform: Theme name: “WhiteSur-dark-solid”

But the look isn’t exactly the same, better when I set QT_STYLE_OVERRIDE to kvantum-dark to my taste …

Hey!

I’m new to Manjaro, how would I go about downgrading the package? I’ve looked online and I can’t find a .tar.gz file that works and the file isn’t in my pacman cache.

Thanks if anyone can help :slight_smile:

Hello @ethan_the_ethan welcome.

sudo pacman -S downgrade to install “downgrade” after that you can use that to downgrade certain packages.

Usage: downgrade [option...] <pkg> [pkg...] [-- pacman_option...]

It will give you a list with possible candidates that are either local (cache) or remote on a mirror which you can downgrade to.

Hey @Th3Z0ne, thanks for responding!

Running sudo downgrade qgnomeplatform gave me a message about setting an environment variable, which I did, and then just prompted to redownload the original version. I had a look on the Arch Linux Repo Archives and I couldn’t find the old version of qgnomeplatform.

I managed to solve it another way following what was said in this forum post from last year (I had a link here but I can’t include links in my replies apparently) by adding the flag QT_QPA_PLATFORMTHEME=qt5ct to ~/.profile.

Thanks for the help anyway and responding so quickly :slight_smile:

Well, I couldn’t get my setup to play nicely with the latest qgnomeplatform package, despite @ethan_the_ethan helpful suggestions, so I just uninstalled it. The QT apps appear to be taking the kvantum themes well enough without it, so hopefully I am not missing anything by not having it installed.

I’m having the same problem after updating manjaro stable…
How can this be solved!!?? I’m having much trouble reading in QT applications

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Same issue here text is barely readable for me

I have just noticed that I am having the same problem. I use very few Qt programs, but when I loaded Calibre, the main interface was virtually unreadable.