Setting prefered xdg-desktop-portal in gnome, to fix titlebars

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1

I am trying to setup both Hyprland and Gnome through gdm, which is working.
I want this because I run one a single laptop. When I am at my desk I want to use gnome, because I like the desktop experience. When I am not connected to multiple screens I want to use Hyprland.

I have installed multiple portals:

# home.nix
xdg.portal.extraPortals = mkForce [
    pkgs.xdg-desktop-portal-gtk # Fallback for both
    pkgs.xdg-desktop-portal-hyprland # For Hyprland
    pkgs.xdg-desktop-portal-gnome # For GNOME
];

Now, my Hyprland works just fine, because I don’t have anything drawn around my windows. But on Gnome, the selection of which portal to use for drawing the titlebar seems to have changed for some applications now.

image
image1260×326 26.8 KB

Note: Signal is blurred using blur-my-shell, without it the titlebar stays white

Is overriding /etc/profiles/per-user/mark/etc/profile.d/hm-session-vars.sh from home.nix with a little if statement on XDG_CURRENT_DESKTOP or XDG_SESSION_DESKTOP the way to go? If so, what variables do I target for setting the right portal? I am a bit lost

Another solution that came to mind is to set variables to support gnome at any time, and to have an exec-once in my Hyprland config that changes the variables to what Hyprland needs

Edit

Solution for Spotify

I needed to tell spotify to use XWayland, because of gnome not implementing some server side protocol, I don’t know. I used spicetify-nix, and set wayland to false

Here’s my home module


let 
  cfg = config.modules.spotify;
  inherit (lib) mkEnableOption mkIf;
in {
  options.modules.spotify = { 
    enable = mkEnableOption "Spotify spicetify configuration file";
  };

  config = mkIf cfg.enable {
    programs.spicetify =
    let
      spicePkgs = inputs.spicetify-nix.legacyPackages.${pkgs.system};
    in
    {
      enable = true;
      wayland = false;
      # ... other options for my system
    };
  };
}

Solution for Signal:

For Signal the issue seems to be that it did not pick up the setting for Legacy Applications.
Tweaks: Appearance → Legacy Applications

# dconf.settings = { ...
"org/gnome/desktop/interface" = {
    gtk-theme = "Adwaita";
    ...
};

fixed it for me