Disable character removing keys in a JavaFX TextField

Question

The title pretty much says it all. I need to disable character-removing keys in a JavaFX TextField. By character-removing keys, I mean DEL and SUPPR.

Right now, this is what I have:

mytextfield.addEventFilter(KeyEvent.KEY_TYPED, new EventHandler<KeyEvent>() {
        public void handle(KeyEvent event) {          
            if (event.getCharacter().matches("[0-9]")) {
                // some stuff that works perfectly here
            }
            event.consume(); // to cancel everything but 0-9 keys
        }
    });

But for some reason, even though the event gets consumed, the end character still gets deleted when pressing delete.

Thanks for your time!

Answer 1

KEY_TYPED will fire an event only after pressing a key that generates a UTF output. KEY_TYPED event will not be generated at BACK_SPACE and DELETE key press. Use the KEY_PRESSED event instead.

mytextfield.addEventFilter(KeyEvent.KEY_PRESSED, new EventHandler<KeyEvent>() {
        public void handle(KeyEvent event) {          
            if (event.getCode() == KeyCode.BACK_SPACE || event.getCode() == KeyCode.DELETE) {
                event.consume(); // to cancel character-removing keys               
            }
        }
    });

Putting the event.consume() inside the if block will cancel only these buttons. The others will work as usual.

This worked fine for me.