xsettingsd: add service module

modules/misc/news.nix

@@ -2125,6 +2125,14 @@ in
           A new module is available: 'programs.sm64ex'.
         '';
       }
+
+      {
+        time = "2021-07-15T13:38:32+00:00";
+        condition = hostPlatform.isLinux;
+        message = ''
+          A new module is available: 'services.xsettingsd'.
+        '';
+      }
     ];
   };
 }

modules/modules.nix

@@ -229,6 +229,7 @@ let
     (loadModule ./services/xembed-sni-proxy.nix { condition = hostPlatform.isLinux; })
     (loadModule ./services/xidlehook.nix { condition = hostPlatform.isLinux; })
     (loadModule ./services/xscreensaver.nix { })
+    (loadModule ./services/xsettingsd.nix { condition = hostPlatform.isLinux; })
     (loadModule ./services/xsuspender.nix { condition = hostPlatform.isLinux; })
     (loadModule ./systemd.nix { })
     (loadModule ./targets/darwin { condition = hostPlatform.isDarwin; })

modules/services/xsettingsd.nix

@@ -0,0 +1,44 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  cfg = config.services.xsettingsd;
+
+in {
+  meta.maintainers = [ maintainers.imalison ];
+
+  options = {
+    services.xsettingsd = {
+      enable = mkEnableOption "xsettingsd";
+
+      package = mkOption {
+        type = types.package;
+        default = pkgs.xsettingsd;
+        defaultText = literalExample "pkgs.xsettingsd";
+        description = ''
+          Package containing the <command>xsettingsd</command> program.
+        '';
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    systemd.user.services.xsettingsd = {
+      Unit = {
+        Description = "xsettingsd";
+        After = [ "graphical-session-pre.target" ];
+        PartOf = [ "graphical-session.target" ];
+      };
+
+      Install.WantedBy = [ "graphical-session.target" ];
+
+      Service = {
+        Environment = "PATH=${config.home.profileDirectory}/bin";
+        ExecStart = "${cfg.package}/bin/xsettingsd";
+        Restart = "on-abort";
+      };
+    };
+  };
+}