Add x11 service for unclutter

modeled after the redshift service

nixos/modules/module-list.nix

@@ -352,6 +352,7 @@
   ./services/web-servers/varnish/default.nix
   ./services/web-servers/winstone.nix
   ./services/web-servers/zope2.nix
+  ./services/x11/unclutter.nix
   ./services/x11/desktop-managers/default.nix
   ./services/x11/display-managers/auto.nix
   ./services/x11/display-managers/default.nix

nixos/modules/services/x11/unclutter.nix

@@ -0,0 +1,33 @@
+{ config, lib, pkgs, ... }:
+with lib;
+let cfg = config.services.unclutter;
+in {
+  options = {
+    services.unclutter.enable = mkOption {
+      type = types.bool;
+      default = false;
+      example = true;
+      description = "Enable unclutter to hide your mouse cursor when inactive";
+    };
+
+    services.unclutter.arguments = mkOption {
+      description = "Arguments to pass to unclutter command";
+      default = "-idle 1";
+      type = types.uniq types.string;
+    };
+  };
+
+  config = mkIf cfg.enable {
+    systemd.services.unclutter = {
+      description = "unclutter";
+      requires = [ "display-manager.service" ];
+      after = [ "display-manager.service" ];
+      wantedBy = [ "graphical.target" ];
+      serviceConfig.ExecStart = ''
+        ${pkgs.unclutter}/bin/unclutter ${cfg.arguments}
+      '';
+      environment = { DISPLAY = ":0"; };
+      serviceConfig.Restart = "always";
+    };
+  };
+}