Install .desktop file for smath-studio

packages/smath-studio.nix

@@ -2,16 +2,22 @@
   appimageTools,
   fetchurl,
   libgdiplus,
-}:
-appimageTools.wrapType2 {
+}: let
   pname = "smath-studio";
   version = "1.3.0.9126";
 
   src = fetchurl {
     url = "https://smath.com/en-US/files/Download/cqSek/SMathStudioDesktop.1_3_0_9126.x86_64.ubuntu-22_04.glibc2.35.AppImage";
-    sha256 = "sha256-4FpdFGPFaPDK6WWSJHVtxcC8auaNkGmHyUtbegij6cQ=";
+    hash = "sha256-4FpdFGPFaPDK6WWSJHVtxcC8auaNkGmHyUtbegij6cQ=";
   };
 
+  appimageContents = appimageTools.extractType2 {
+    inherit pname version src;
+  };
+in
+  appimageTools.wrapType2 {
+    inherit pname version src;
+
     extraPkgs = pkgs:
       with pkgs; [
         gtk2
@@ -20,4 +26,10 @@ appimageTools.wrapType2 {
     profile = ''
       export LD_PRELOAD="${libgdiplus}/lib/libgdiplus.so.0"
     '';
+
+    extraInstallCommands = ''
+      install -m 444 -D ${appimageContents}/*.desktop -t $out/share/applications
+      sed -i "s|^Exec=.*|Exec=smath-studio %U|" $out/share/applications/*.desktop
+      cp -r ${appimageContents}/usr/share/icons $out/share
+    '';
   }