Remove Old Snow Leopard Shortcut For Spaces - Cmd-Middle Button

It’s a bit tricky, but today I fixed a small problem of an obsolete shortcut in OS X Lion. I used to have Cmd-Right on Exposé and Cmd-Middle on Spaces, to have both functions short at hand. After I upgraded to Lion from Snow Leopard, Spaces and Exposé are merged into Mission Control, which was a wise decision, but my mouse shortcuts were migrated BOTH to Mission Control. Great not to loose the shortcuts, but bad not to be able to change them again - Cmd-Middle has been vanished from System Preferences and only Cmd-Right showed up as a shortcut for Mission Control.

An now for the solution: Lucky me, my other Mac was still on Snow Leopard and I could check which file contains the Cmd-Middle shortcut. I did this by using fseventer, a tool to display file system events recorded by OS X. It showed me, that ~/Library/Preferences/com.apple.hotkeyshortcut.plist was the file in charge. I then made a copy of the old file and disabled the shortcut temporarily. Then I checked, what changed in the file by using FileMerge (comes with XCode IIRC) and using this additional trick. The result is given in the picture.

The file was renamed for Lion however and is called com.apple.symbolichotkeys.plist now. Then, I edited the file using my favourite editor (vim), but before I had to convert it to xml format using the following line

plutil -convert xml1 com.apple.symbolichotkeys.plist

After fixing the lines for key 87 and key 88, I converted the file back using:

plutil -convert binary1 com.apple.symbolichotkeys.plist

And that’s it again,
cheers!
iss