How to set a window invisible but focused?

Question

I want to set a window invisible but focused for a fraction of seconds.

I'm writing a key board emulator using Robot class as a part of project for detecting key loggers.

Keyboard emulator should not disrupt the normal work of the user, so I want to set a hidden window focused for a short span so that the keys entered by the robot class received by the hidden window instead of normal user applications.

Is there any way to do this in Java when window is actually invisible? How to do this? at least in windows platform?

How about transparent full screen window in case the above thing is not possible?

My base paper: http://www.atlantis-press.com/php/download_paper.php?id=9980

Answer 1

Is there any way to do this in Java when window is actually invisible?

No. Not in pure Java at least.

How about transparent full screen window in case the above thing is not possible?

A transparent window does not receive events. So again, no.