wysota,

Thanks for all your replies.

As I still did not figure how to receive the original Xlib event in Qt. ( It should be able to, but I just cann't work it out.)
As you said, x11EventFilter() maybe the reason.
Although I still did not make it.

Now, my current solution is using a C program to receive XEvent and send that event into a java client.( still stuck by a problem to find the WindowID of java GUI.)
But, anyway, thank again.

Thanks for all your effor, all your instruction and etc.

With regards.

Tiger