So I tried making .profile again. And execute source ~/.profile.
I made .profile by copying them from freshly installed manjaro xfce with new user and I found that it should be export QT_QPA_PLATFORMTHEME="qt5ct" and not QT_QPA_PLATFORMTHEME=qt5ct.
now qt theme selector is using the correct theme. And theme applied correctly to some qt apps such as audacious. But it’s not applied to qbittorrent and smplayer. I am pretty sure qbittorrent use correct gtk theme when I was using Gnome. And it also uses correct dark theme in freshly installed manjaro xfce4 with new user.
I don’t like/use kvantum, it is not even installed on my system (it is an alien IMO and does not belong to xfce).
Now themes like adwaita, greybird, colloid, fluent, yaru, … will work fine in light and dark variants.
Adwaita is the default GNOME theme. The GTK 3 version is included in the gtk3 package, while the GTK 2 version is in gnome-themes-extra. adwaita-qt is a Qt port of the Adwaita theme. Unlike #QGtkStyle, which mimics the GTK 2 theme, it provides a native Qt style made to look like the GTK 3 Adwaita. It can be installed with the adwaita-qt4AUR, adwaita-qt5 and adwaita-qt6 packages (it might require some time for compiling) for the Qt 4, 5 and 6 versions, respectively.
Ehm my bad… it looks like, it the issue was the theme I’m using. Because qt theme doesn’t change directly when we changed the settings, combined with closing qbittorrent doesn’t close the actual app, it confuses me.
If I used theme that I previously used in gnome, Vertex-Dark, qbittorrent will use dark time just like before. It’s definitely not vertex-dark but it was dark nonetheless.
So now that I realized the behavior are the same with freshly installed xfce user, I am relieved. I’ll check out that article on archwiki.
But I still wonder why qbittorrent isn’t using theme from qt5ct. Is it because it’s not qt5?