'Use dark theme' unfortunately doesn't work

[LavaHeron]

Using the switch for dark theme in the preferences, has no effect on the appearance of the app.

I found the entry "use_dark_theme": true under .var/app/io.github.sharkwouter.Minigalaxy/config/minigalaxy/config.json, it is set correctly, but the user interface remains light.

(I'm currently testing Pop!_OS COSMIC, a new Rust-based desktop environment for Pop!_OS. So if the system colors are used for this, then the display problem could only exist for me.
In case this problem only occurs to me: Is there a config file or another way to change all the colors manually?)

Minigalaxy version: 1.3.1 (via Flathub)

[sharkwouter]

This surprises me. It does work just fine on Debian if I install the 1.3.1 deb package, so this seems like a Flatpak specific issue.

To your second question, in usr/share/minigalaxy/ in the flatpak filesystem there should be a file called style.css. You can modify that one to change colors.

[ell1e]

I use the 1.3.1 flatpak (latest or close to latest) on the Alpine-derivate postmarketOS, and for me the toggle works. I just tested it. So it might be some flatpak and Pop OS interaction.

[sharkwouter]

Interesting, thanks for testing @ell1e

[GB609]

How does the theming work, is it related to GTK?
If Minigalaxy utilises the system's dark GTK theme, maybe there's an issue with it either not existing or not being found by minigalaxy?
I just tested it as well, with native Minigalaxy directly run from the sources, and enabling the dark theme doesn't work for me either.
I'm on ArchLinux, using LightDM -> OpenBox -> LXQT config for display/window management.

[LavaHeron]

Thanks for the info about the style.css. The file is located in .local/share/flatpak/app/io.github.sharkwouter.Minigalaxy/x86_64/stable/..../files/share/minigalaxy simple because there is only one style.css.
I tried to achieve the best possible look, but there are certainly still some problems. But maybe this will help other people too.
These are the entries I made in the style.css (v2.0):

window, messagedialog box, dialog, switch, button {
  color: #cdcdcd;
  background: #353535;
}

entry {
  color: #cdcdcd;
  background: #303030;
  border: 1px solid black;
}

headerbar:backdrop {
  color: #adadad;
  background: #252525;
}

headerbar, popover, popover button, menu {
  color: #cdcdcd;
  background: #151515;
}

button:hover, button.suggested-action:hover, filechooserbutton:hover {
  background: #151515;
}

entry:focus, progressbar progress {
  outline: none;
  box-shadow: none;
  border: 1px solid darkslateblue;
}

button.suggested-action, switch:checked, separator, menubutton:hover, menuitem:hover, modelbutton:hover, popover button:hover, progressbar progress {
  background: darkslateblue;
}

button:disabled, switch:disabled, entry:disabled {
  color: darkgray;
  background: dimgrey;
}

progressbar trough {
  border: 1px solid rgba(1%, 1%, 1%, 0);
  background: rgba(50%, 50%, 50%, 0.5);
}

progressbar, progressbar trough.empty progress {
  border: none;
  background: none;
}

progressbar trough.full progress {
  background: limegreen;
  border: 1px solid limegreen;
}

window.popup {
  background: none;
}

buttonbox, grid, scrolledwindow, flowbox, box, titlebar, headerbar, headerbar:backdrop, popover button {
  border: none;
  outline: none;
  box-shadow: none;
}

switch, button {
  text-shadow: none;
  box-shadow: none;
  border: 1px solid black;
}

PS: thank you all very much for Minigalaxy, it's really great!