protected void addCurrentLineHighlightListeners() {
		boolean add = true;
		MouseMotionListener[] mouseMotionListeners = getMouseMotionListeners();
		for (int i=0; i<mouseMotionListeners.length; i++) {
			if (mouseMotionListeners[i]==mouseListener) {
				add = false;
				break;
			}
		}
		if (add==true) {
			//System.err.println("Adding mouse motion listener!");
			addMouseMotionListener(mouseListener);
		}
		MouseListener[] mouseListeners = getMouseListeners();
		for (int i=0; i<mouseListeners.length; i++) {
			if (mouseListeners[i]==mouseListener) {
				add = false;
				break;
			}
		}
		if (add==true) {
			//System.err.println("Adding mouse listener!");
			addMouseListener(mouseListener);
		}
	}