add: desktop xdg integration

modules/desktop/default.nix

@@ -42,6 +42,8 @@
     then "lightdm"
     else "none";
 in {
+  imports = [./xdg.nix];
+
   options.desktop = {
     displayManager = lib.mkOption {
       type = lib.types.enum ["auto" "none" "gdm" "lightdm" "ly"];
@@ -141,6 +143,11 @@ in {
         enable = true;
         wrapperFeatures.gtk = true;
         extraPackages = cfg.sway.extraPackages;
+        extraSessionCommands = ''
+          export XDG_SESSION_TYPE=wayland
+          export XDG_SESSION_DESKTOP=sway
+          export NIXOS_OZONE_WL=1
+        '';
       };
     })
 

modules/desktop/xdg.nix

@@ -0,0 +1,42 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}: let
+  cfg = config.desktop;
+  needsGtkPortal = cfg.xfce.enable || cfg.hyprland.enable;
+  usesPortal = cfg.gnome.enable || cfg.xfce.enable || cfg.sway.enable || cfg.hyprland.enable;
+in {
+  config = lib.mkMerge [
+    # GNOME and Sway configure their own portals in NixOS. XFCE needs a
+    # portal; Hyprland benefits from GTK as a fallback to its native one.
+    (lib.mkIf needsGtkPortal {
+      xdg.portal = {
+        enable = true;
+        extraPortals = [pkgs.xdg-desktop-portal-gtk];
+      };
+    })
+
+    (lib.mkIf (cfg.sway.enable || needsGtkPortal) {
+      xdg.portal.config.common.default = ["gtk"];
+    })
+
+    (lib.mkIf (usesPortal && config.services.gnome.gnome-keyring.enable) {
+      xdg.portal.config.common."org.freedesktop.impl.portal.Secret" = ["gnome-keyring"];
+    })
+
+    (lib.mkIf (cfg.sway.enable && config.services.gnome.gnome-keyring.enable) {
+      xdg.portal.config.sway."org.freedesktop.impl.portal.Secret" = ["gnome-keyring"];
+    })
+
+    # A per-desktop config takes precedence over Hyprland's packaged config,
+    # so include its native portal whenever adding a Secret preference.
+    (lib.mkIf (cfg.hyprland.enable && config.services.gnome.gnome-keyring.enable) {
+      xdg.portal.config.hyprland = {
+        default = ["hyprland" "gtk"];
+        "org.freedesktop.impl.portal.Secret" = ["gnome-keyring"];
+      };
+    })
+  ];
+}