xfce.xfwm4: Move away from mkXfceDerivation

To reduce the diff when build system change comes.
mkXfceDerivation is generally pointless with meson.

pkgs/desktops/xfce/core/xfwm4/default.nix

@@ -1,8 +1,12 @@
 {
+  stdenv,
   lib,
-  mkXfceDerivation,
-  exo,
+  fetchFromGitLab,
+  gettext,
   librsvg,
+  pkg-config,
+  xfce4-dev-tools,
+  wrapGAppsHook3,
   dbus-glib,
   libepoxy,
   gtk3,
@@ -13,18 +17,27 @@
   libwnck,
   libXpresent,
   xfconf,
+  gitUpdater,
 }:
 
-mkXfceDerivation {
-  category = "xfce";
+stdenv.mkDerivation (finalAttrs: {
   pname = "xfwm4";
   version = "4.20.0";
 
-  sha256 = "sha256-5UZQrAH0oz+G+7cvXCLDJ4GSXNJcyl4Ap9umb7h0f5Q=";
+  src = fetchFromGitLab {
+    domain = "gitlab.xfce.org";
+    owner = "xfce";
+    repo = "xfwm4";
+    tag = "xfwm4-${finalAttrs.version}";
+    hash = "sha256-5UZQrAH0oz+G+7cvXCLDJ4GSXNJcyl4Ap9umb7h0f5Q=";
+  };
 
   nativeBuildInputs = [
-    exo
-    librsvg
+    gettext
+    librsvg # rsvg-convert
+    pkg-config
+    xfce4-dev-tools
+    wrapGAppsHook3
   ];
 
   buildInputs = [
@@ -40,8 +53,20 @@ mkXfceDerivation {
     xfconf
   ];
 
+  configureFlags = [ "--enable-maintainer-mode" ];
+  enableParallelBuilding = true;
+
+  passthru.updateScript = gitUpdater {
+    rev-prefix = "xfwm4-";
+    odd-unstable = true;
+  };
+
   meta = {
     description = "Window manager for Xfce";
+    homepage = "https://gitlab.xfce.org/xfce/xfwm4";
+    mainProgram = "xfwm4";
+    license = lib.licenses.gpl2Plus;
+    platforms = lib.platforms.linux;
     teams = [ lib.teams.xfce ];
   };
-}
+})