shortcuts

[Vasil Nemkov]

Hi.

I would like to add a support of a key-release feature to the XFCE
hotkeys. I've checked out source of gtk-2 and found that it already
supports key-release hotkeys.
Question is: What part inside XFCE does processes the keyboard input
and invokes the commands attached to a hotkey?

Details: I run Linux Mint 16 XFCE (XFCE ver 4.10.1) flavor with
whisker menu installed. So I would like to bind <Super_L> key to open
said whisker menu, but on key release, not on key press. So I opened
the XFCE settings editor and added an entry alongside the existing one
at xfce-keyboard-shortcuts channel. The property name is
"/commands/custom/<Release>Super_L", command is
'xfce4-popup-whiskermenu', which is a shell-script. The existing
binding of the Super_L key was removed.
Now when I press the Super_L key, nothing happens.
After applying some magic tricks I found that
'xfce4-popup-whiskermenu' used to be executed from process 'init',
launched with 'init --user' command.

To highlight the question: What should I modify in oder to hook custom
commands on key release event in XFCE environment?

-- 
Best regards,
Vasily Nemkov