nixos/graphical-desktop: extract generic graphical things from xserver

This is required to fix the keymap in SDDM without X.

nixos/modules/module-list.nix

@@ -710,6 +710,7 @@
   ./services/misc/gogs.nix
   ./services/misc/gollum.nix
   ./services/misc/gpsd.nix
+  ./services/misc/graphical-desktop.nix
   ./services/misc/greenclip.nix
   ./services/misc/guix
   ./services/misc/headphones.nix

nixos/modules/services/misc/graphical-desktop.nix

@@ -0,0 +1,54 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+let
+  xcfg = config.services.xserver;
+  dmcfg = config.services.displayManager;
+in
+{
+  config = lib.mkIf (xcfg.enable || dmcfg.enable) {
+    # The default max inotify watches is 8192.
+    # Nowadays most apps require a good number of inotify watches,
+    # the value below is used by default on several other distros.
+    boot.kernel.sysctl = {
+      "fs.inotify.max_user_instances" = lib.mkDefault 524288;
+      "fs.inotify.max_user_watches" = lib.mkDefault 524288;
+    };
+
+    environment = {
+      # localectl looks into 00-keyboard.conf
+      etc."X11/xorg.conf.d/00-keyboard.conf".text = ''
+        Section "InputClass"
+          Identifier "Keyboard catchall"
+          MatchIsKeyboard "on"
+          Option "XkbModel" "${xcfg.xkb.model}"
+          Option "XkbLayout" "${xcfg.xkb.layout}"
+          Option "XkbOptions" "${xcfg.xkb.options}"
+          Option "XkbVariant" "${xcfg.xkb.variant}"
+        EndSection
+      '';
+      systemPackages = with pkgs; [
+        nixos-icons # needed for gnome and pantheon about dialog, nixos-manual and maybe more
+        xdg-utils
+      ];
+    };
+
+    fonts.enableDefaultPackages = lib.mkDefault true;
+
+    hardware.opengl.enable = lib.mkDefault true;
+
+    programs.gnupg.agent.pinentryPackage = lib.mkOverride 1100 pkgs.pinentry-gnome3;
+
+    systemd.defaultUnit = lib.mkIf (xcfg.autorun || dmcfg.enable) "graphical.target";
+
+    xdg = {
+      autostart.enable = true;
+      menus.enable = true;
+      mime.enable = true;
+      icons.enable = true;
+    };
+  };
+}

nixos/modules/services/x11/xserver.nix

@@ -651,8 +651,6 @@ in
                     || config.services.greetd.enable);
       in mkIf (default) (mkDefault true);
 
-    hardware.opengl.enable = mkDefault true;
-
     services.xserver.videoDrivers = mkIf (cfg.videoDriver != null) [ cfg.videoDriver ];
 
     # FIXME: somehow check for unknown driver names.
@@ -686,19 +684,6 @@ in
           # -xkbdir command line option does not seems to be passed to xkbcomp.
           "X11/xkb".source = "${cfg.xkb.dir}";
         })
-      # localectl looks into 00-keyboard.conf
-      //{
-          "X11/xorg.conf.d/00-keyboard.conf".text = ''
-            Section "InputClass"
-              Identifier "Keyboard catchall"
-              MatchIsKeyboard "on"
-              Option "XkbModel" "${cfg.xkb.model}"
-              Option "XkbLayout" "${cfg.xkb.layout}"
-              Option "XkbOptions" "${cfg.xkb.options}"
-              Option "XkbVariant" "${cfg.xkb.variant}"
-            EndSection
-          '';
-        }
       # Needed since 1.18; see https://bugs.freedesktop.org/show_bug.cgi?id=89023#c5
       // (let cfgPath = "X11/xorg.conf.d/10-evdev.conf"; in
         {
@@ -718,31 +703,12 @@ in
         xorg.xprop
         xorg.xauth
         pkgs.xterm
-        pkgs.xdg-utils
         xorg.xf86inputevdev.out # get evdev.4 man page
-        pkgs.nixos-icons # needed for gnome and pantheon about dialog, nixos-manual and maybe more
       ] config.services.xserver.excludePackages
       ++ optional (elem "virtualbox" cfg.videoDrivers) xorg.xrefresh;
 
     environment.pathsToLink = [ "/share/X11" ];
 
-    xdg = {
-      autostart.enable = true;
-      menus.enable = true;
-      mime.enable = true;
-      icons.enable = true;
-    };
-
-    # The default max inotify watches is 8192.
-    # Nowadays most apps require a good number of inotify watches,
-    # the value below is used by default on several other distros.
-    boot.kernel.sysctl."fs.inotify.max_user_instances" = mkDefault 524288;
-    boot.kernel.sysctl."fs.inotify.max_user_watches" = mkDefault 524288;
-
-    programs.gnupg.agent.pinentryPackage = lib.mkOverride 1100 pkgs.pinentry-gnome3;
-
-    systemd.defaultUnit = mkIf cfg.autorun "graphical.target";
-
     systemd.services.display-manager =
       { description = "Display Manager";
 
@@ -902,7 +868,6 @@ in
         ${cfg.extraConfig}
       '';
 
-    fonts.enableDefaultPackages = mkDefault true;
     fonts.packages = [
       (if cfg.upscaleDefaultCursor then fontcursormisc_hidpi else pkgs.xorg.fontcursormisc)
       pkgs.xorg.fontmiscmisc