Getting the keyboard modifiers key state before injecting event.

Question

I'm using the Robot to inject keyboard events into a host computer from multiple clients.
Since each client can have different modifiers keys (i.e. Shift, Alt, Ctrl, ...) set at a time and
clients can interrupt each other, I need to be able to read from the host computer what
modifier keys are set at that moment to get things back into synch.
The KeyEvent class has a way to get the modifier keys through:
KeyEvent.isShiftDown();
KeyEvent.isControlDown():
But this doesn't help (apparently) because that information is only available to a
Keyboard listener when a key is pressed.
What I need is a way to "get" the current keyboard modifier keys state before injecting
an event through the Robot.
Would anyone know how to do this?

Answer 1

So... the clients send input events to the host and the host in turn simulates those events with the use of a Robot. Is that correct?
If so then the program needs to save the last injected keyboard input that had a modifier mask in a field somewhere. Whenever you need to ask if any modifier keys are being pressed, you need only to look at this field and see if it is a pressed event. However, this method won't be able to detect a person physically at the host computer typing stuff.
The central problem is that you can query keyboard input from OS (such as asking if shift is currently pressed) without a focused window using the standard api. But a focused window kind of defeats the purpose of what you are trying to do.