code: @Override
  	public void dragOver(final DragEvent dragEvent) {
  
  		if (dragEvent.getSource() instanceof Region) {
  			if (dragEvent.getX() > 100
  					&& dragEvent.getX() < ((Region) dragEvent.getSource()).getWidth() - 100
  					|| dragEvent.getY() > 100
  					&& dragEvent.getY() < ((Region) dragEvent.getSource()).getHeight() - 100) {
  
  				System.out.println("drag OVER on => " + controller().model().key());
  
  				controller().view().drawMarker(dragEvent.getX(), dragEvent.getY());
  				dragEvent.consume();
  			} else {
  				controller().view().removeMarker();
  			}
  		}
  	}
docs: {@inheritDoc}