feat: Configure XDG portal

modules/home/users/crumb/niri.nix

@@ -24,6 +24,37 @@ in {
 
     services.polkit-gnome.enable = true;
 
+    # File-picker.
+    home.packages = [ pkgs.nautilus ];
+
+    # Enable the XDG portal, an interface for programs to request
+    # permissions/resources.  This is necessary to screen-cast on
+    # Wayland/Pipewire.
+    #
+    # See https://github.com/YaLTeR/niri/wiki/Important-Software#portals.
+    # Niri's NixOS module automatically brings in xdg-desktop-portal-gnome and
+    # gnome-keyring.
+    xdg.portal = {
+      enable = true;
+      xdgOpenUsePortal = true;
+
+      extraPortals = [
+        pkgs.xdg-desktop-portal-gtk
+        pkgs.xdg-desktop-portal-gnome
+      ];
+
+      # Use xdg-desktop-portal-gtk by default, but fallback to
+      # xdg-desktop-portal-gnome for screenshots and screen-casts, two important
+      # features unsupported by the GTK implementation.  See implementations and
+      # their supported interfaces at
+      # https://wiki.archlinux.org/title/XDG_Desktop_Portal.
+      config.niri = {
+        default = [ "gtk" ];
+        "org.freedesktop.impl.portal.Screenshot" = [ "gnome" ];
+        "org.freedesktop.impl.portal.ScreenCast" = [ "gnome" ];
+      };
+    };
+
     systemd.user.services.xwayland-satellite =
       lib.mkIf cfg.xwayland-satellite.enable {
         Service.ExecStart =

modules/nixos/niri.nix

@@ -15,24 +15,6 @@ in {
     };
 
     security.pam.services.swaylock = {};
-    
-    # Necessary for e.g. screensharing.
-    xdg.portal = {
-      enable = true;
-      # See https://github.com/YaLTeR/niri/wiki/Important-Software#portals.
-      # Niri's NixOS module appears to automatically bring in
-      # xdg-desktop-portal-gnome and gnome-keyring.
-      extraPortals = [
-        pkgs.xdg-desktop-portal-gtk
-        pkgs.xdg-desktop-portal-wlr
-      ];
-      xdgOpenUsePortal = true;
-      config.preferred = {
-        default = [ "gtk" ];
-        "org.freedesktop.impl.portal.Screenshot" = [ "wlr" ];
-        "org.freedesktop.impl.portal.ScreenCast" = [ "wlr" ];
-      };
-    };
   };
 }