gwt_handle_key_up.java

// Java snippet for GWT to trap keyboard keyUp events at the document level.
// In other words, no KeyUpHandler needed (nor does Document provide a hook).

		Event.addNativePreviewHandler(new Event.NativePreviewHandler() {
			@Override
			public void onPreviewNativeEvent(NativePreviewEvent event) {
				if (event.getTypeInt() == Event.ONKEYUP) {
					// do something with the key code
					// doSomething(event.getNativeEvent().getKeyCode());

					event.cancel();
				}
			}
		});