double x0 = value;
            double x1 = value + getXOffset();
            double y0 = dataArea.getMaxY();
            double y1 = y0 - getYOffset();
            double y2 = dataArea.getMinY();
            line1 = new Line2D.Double(x0, y0, x1, y1);
            line2 = new Line2D.Double(x1, y1, x1, y2);