Comment 8 for bug 943194

I've now tested the idea I had last night to try and make compiz use purely passive grabs for tap detection. It doesn't work half the time. For some strange reason XGrabKey (keycode=AnyKey, modifiers=Alt) returns success but then fails to actually grab Alt+any_other_key or to report any such key events.

Essentially, the biggest problem with the current tap detection is that it uses an active grab. As soon as you start the active grab, that causes a focus change. And that focus change causes the underlining/highlighting of any menu that would be triggered by pressing Alt to be cancelled immediately. This is the same root cause as bug 943851.