trigger: add desktop item

pkgs/games/trigger/default.nix

@@ -1,5 +1,5 @@
 { lib, fetchurl, stdenv, runtimeShell, SDL2, freealut, SDL2_image, openal, physfs
-, zlib, libGLU, libGL, glew, tinyxml-2 }:
+, zlib, libGLU, libGL, glew, tinyxml-2, copyDesktopItems, makeDesktopItem }:
 
 stdenv.mkDerivation rec {
   pname = "trigger-rally";
@@ -10,6 +10,8 @@ stdenv.mkDerivation rec {
     sha256 = "016bc2hczqscfmngacim870hjcsmwl8r3aq8x03vpf22s49nw23z";
   };
 
+  nativeBuildInputs = [ copyDesktopItems ];
+
   buildInputs = [
     SDL2
     freealut
@@ -42,8 +44,22 @@ stdenv.mkDerivation rec {
     exec $out/games/trigger-rally "$@"
     EOF
     chmod +x $out/bin/trigger-rally
+
+    mkdir -p $out/share/pixmaps/
+    ln -s $out/share/games/trigger-rally/icon/trigger-rally-icons.svg $out/share/pixmaps/trigger.svg
   '';
 
+  desktopItems = [
+    (makeDesktopItem {
+      name = "Trigger";
+      exec = "trigger-rally";
+      icon = "trigger";
+      desktopName = "Trigger";
+      comment = "Fast-paced 3D single-player rally racing game";
+      categories = [ "Game" "ActionGame" ];
+    })
+  ];
+
   meta = {
     description = "A fast-paced single-player racing game";
     homepage = "http://trigger-rally.sourceforge.net/";