public void movePointer(Utility.Direction dir){
        pointerY += dir.getDeltaY();
        pointerX += dir.getDeltaX();
        pointerY = pointerY < 0 ? 0 : pointerY > (items.size()-1)/columns ? (items.size()-1)/columns : pointerY;
        pointerX = pointerX < 0 ? 0 : pointerX > columns-1 ? columns-1 : pointerX;
    }