swaybg systemd service

lib/modules/display.nix

@@ -8,14 +8,32 @@ let
     + concatStringsSep "\n" (map displayHyprlandSetting displays);
 
   displayHyprlandSetting = display:
-    "monitor = " + display.name +
+    "monitor = " + specificDisplay display +
     ", " + resToString display.resolution +
     ", " + display.position +
-    ", " + toString display.scaling +
-    (if ( display.wallpaper != "" ) then ''
+    ", " + toString display.scaling;
 
-      exec-once = ${pkgs.swaybg}/bin/swaybg -o ${display.name} -i ${display.wallpaper} &
-    '' else "");
+  swaybgJob = displays:
+    {
+      Unit = {
+        Description = "SwayBG";
+      };
+      Service = {
+        ExecStart = "${pkgs.swaybg}/bin/swaybg " +
+          concatStringsSep " " (map swaybgCmd displays);
+      };
+      Install = {
+        WantedBy = ["graphical-session.target"];
+      };
+    };
+
+  swaybgCmd = display:
+    if (display.wallpaper != "") then "-o ${display.name} -i ${display.wallpaper}" else "";
+
+  specificDisplay = display:
+    if display.description == ""
+    then display.name
+    else "desc:" + display.description;
 
   resolutionType = types.submodule ({ x, y, freq, ... }:
     {
@@ -43,6 +61,10 @@ let
         name = mkOption {
           description = "name of the display";
         };
+        description = mkOption {
+          description = "description of display from hyprctl monitors";
+          default = "";
+        };
         scaling = mkOption {
           type = types.float;
           default = 1.0;
@@ -83,6 +105,8 @@ in
       {
         wayland.windowManager.hyprland.extraConfig = mkIf (cfg.displays != [ ])
           (renderDisplaysForHyprland cfg.displays);
+
+        systemd.user.services.swaybg = swaybgJob cfg.displays;
       }
     ];
   };