SWT: How do you register KeyUp events when no Control have focus?

Question

Im am making an Java SWT program that is required to run on both Linux and Windows.

I use the following Code to listen for KeyUp events:

Control.addListener(SWT.KeyUp, new Listener() {

public void handleEvent(Event arg0) {
 System.out.println("Event");

}

});

But this does not trigger when no control has focus.

Do anyone know of a place i can add a listener that acts as a Catch-all?

Answer 1

There is a GetAsyncKeyState in User32 that you can access through PInvoke or use the Managed Windows API wrapper for it - KeyboardKey retrieves keyboard data.

That gives you a way of accessing keyboard activity regardless of what currently has focus. It's low level and requires a bit of extra work to tie it into a regular event system, but it's great for stuff like hotkeys where you want to pick up information from another window and use it in your application.

Answer 2

try following method in Display class:

public void addListener ( int eventType, Listener listener ) 

Answer 3

I have not been able to find a solution to this. I suspect none exist

Answer 4

The only way of doing this that I'm aware of is by placing a filter on the Display. Take note that multiple Shells may operate on one Display, so you should be careful!

shell.getDisplay().addFilter(SWT.KeyDown, new Listener() {
    public void handleEvent(final Event event) {
        System.out.println(event);
    }
});