public void removeCellDragListener(Cell curCell) {
        if (curCell == null)
            return;
        MouseListener[] mls = curCell.getMouseListeners();
        for (MouseListener l : mls) {
            if (l instanceof CellDragListener) {
                curCell.removeMouseListener(l);
            }
        }
        MouseMotionListener[] mmls = curCell.getMouseMotionListeners();
        for (MouseMotionListener l : mmls) {
            if (l instanceof CellDragListener) {
                curCell.removeMouseMotionListener(l);
            }
        }
    }