xwayland-satellite: initial module

Signed-off-by: Myned <dev@bjork.tech>

options/custom/services/xwayland-satellite.nix

@@ -0,0 +1,47 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+with lib; let
+  xwayland-satellite = "${pkgs.xwayland-satellite}/bin/xwayland-satellite";
+
+  cfg = config.custom.services.xwayland-satellite;
+in {
+  options.custom.services.xwayland-satellite.enable = mkOption {default = false;};
+
+  config = mkIf cfg.enable {
+    # HACK: Use official module if added
+    # BUG: Fractional scaling is currently not supported
+    # https://github.com/Supreeeme/xwayland-satellite/issues/11
+    # Rootless Xwayland support as a user service
+    # https://github.com/Supreeeme/xwayland-satellite
+
+    # https://github.com/Supreeeme/xwayland-satellite/blob/main/resources/xwayland-satellite.service
+    systemd.user.services.xwayland-satellite = {
+      enable = true;
+
+      unitConfig = {
+        Description = "Xwayland outside your Wayland";
+        BindsTo = ["graphical-session.target"];
+        PartOf = ["graphical-session.target"];
+        After = ["graphical-session.target"];
+        Requisite = ["graphical-session.target"];
+      };
+
+      serviceConfig = {
+        Type = "notify";
+        NotifyAccess = "all";
+        ExecStart = xwayland-satellite;
+        StandardOutput = "journal";
+      };
+
+      wantedBy = ["graphical-session.target"];
+    };
+
+    environment.sessionVariables = {
+      DISPLAY = ":0"; # Assume first display
+    };
+  };
+}