One of my highly used hotkey got hijacked by another program in Ubuntu. But I don't know which program it is. By some researching, I found there is a discussion for Windows. (Here). But I could not find related solution for Ubuntu.
So, Is there some way in Ubuntu to determine that: when I press a key combination, which program consumes this key combination?
The linked question does solved my situation. But I think this question here should be kept as a separate thread, because finding a generic solution here will help solve other hotkey related problems in Ubuntu.