Can't get the theming right for flatpaks in plasma

[pebcak]

I have followed the following how-to written by @linesma

[How To] Consistent Flatpak Theming in KDE Plasma

I know that I am talking heresy here, I use 2 Flatpaks on my system, Skype and Spotify. Yes, I know that they are in the AUR. The Flatpak versions work the best for me. The one thing that I do not like about Flatpaks, is how they ignore my GTK theming preferences that I have set in the Plasma Settings. The official solution from the Flatpak devs, is to install the wanted theme as a Flatpak. I personally think this solution is not ideal. Why have two versions of a theme installed just to fix a li…

but it doesn’t seem to get it right for my flatpaks. Not sure if something has changed since the how-to was written. Would appreciate to get some help to make this work.

This is the content of ~/.config/gtk-3.0/settings.ini:

[Settings]
gtk-application-prefer-dark-theme=true
gtk-button-images=true
gtk-cursor-theme-name=breeze_cursors
gtk-cursor-theme-size=24
gtk-decoration-layout=icon:minimize,maximize,close
gtk-enable-animations=true
gtk-font-name=Noto Sans,  10
gtk-icon-theme-name=breeze-dark
gtk-menu-images=true
gtk-modules=colorreload-gtk-module:window-decorations-gtk-module:appmenu-gtk-module
gtk-primary-button-warps-slider=false
gtk-shell-shows-menubar=1
gtk-theme-name=Breeze
gtk-toolbar-style=3

[petsam]

Something you could consider and try is what toolkit is the flatpak app using and if Gnome 42 updates might break it.
Do you use any flatpak gtk3/4 theme?

@pebcak

~/.config/gtk-3.0/settings.ini

Maybe add gtk-4.0 as well?

@pebcak

gtk-application-prefer-dark-theme=true

This is depreciated in Gnome 42 (produces log messages in my journal). I have deleted this setting in my config files.

[pebcak]

Thanks for the reply @petsam!

Sorry for my lack of understanding but is this relevant for Plasma as well?

In Gnome, I have no issues with the theming after the upgrade to 42.

These are the themes currently installed in Gnome 42:

Adwaita dark GTK theme                            org.gtk.Gtk3theme.Adwaita-dark                                                    3.22              system
Arc-Dark Gtk theme                                org.gtk.Gtk3theme.Arc-Dark                                                        3.22              system
Breeze GTK theme                                  org.gtk.Gtk3theme.Breeze                                                          3.22              system
Mint-Y-Dark-Aqua Gtk Theme                        org.gtk.Gtk3theme.Mint-Y-Dark-Aqua                                                3.22              system
Mint-Y-Dark-Grey Gtk Theme                        org.gtk.Gtk3theme.Mint-Y-Dark-Grey                                                3.22              system
Mint-Y-Dark-Pink Gtk Theme                        org.gtk.Gtk3theme.Mint-Y-Dark-Pink                                                3.22              system
Mint-Y-Dark-Purple Gtk Theme                      org.gtk.Gtk3theme.Mint-Y-Dark-Purple                                              3.22              system
Mint-Y-Dark-Teal Gtk Theme                        org.gtk.Gtk3theme.Mint-Y-Dark-Teal                                                3.22              system

Also forgot to tell in OP that I had already added the settings.ini for gtk-4.0 as well. But to no avail.

[petsam]

@pebcak

is this relevant for Plasma as well?

It’s relevant to gui toolkits (gtk2/3, qt5/6, etc), though here your gtk theme (in flatpak).
AFAIK and IIRC, you might install a gtk theme of type flatpak (unless this is for snaps… ).
Edit: It seems there are flatpak themes. Maybe find one that does the job?

Anyway, if the flatpak app uses qt, then you need to fix flatpak qt theming. If gtk, the gtk. At least this is how I understand it. I have not played enough with flatpaks

[pebcak]

@petsam

It’s relevant to gui toolkits (gtk2/3, qt5/6, etc), though here your gtk theme (in flatpak)

Thanks for the explanation!
I feel I have to dig a bit deeper into how everything comes into play in flatpaks.

@petsam

Anyway, if the flatpak app uses qt, then you need to fix flatpak qt theming. If gtk, the gtk.

Alright. I will have to find out what toolkit is used in each of the flatpaks I have installed.

Thanks again for your explanations and hints! Now I know where to start.