code: public void drawLine(PdfContentByte canvas, float leftX, float rightX, float y) {
      	float w;
          if (getPercentage() < 0)
              w = -getPercentage();
          else
              w = (rightX - leftX) * getPercentage() / 100.0f;
          float s;
          switch (getAlignment()) {
              case Element.ALIGN_LEFT:
                  s = 0;
                  break;
              case Element.ALIGN_RIGHT:
                  s = rightX - leftX - w;
                  break;
              default:
                  s = (rightX - leftX - w) / 2;
                  break;
          }
          canvas.setLineWidth(getLineWidth());
          if (getLineColor() != null)
              canvas.setColorStroke(getLineColor());
          canvas.moveTo(s + leftX, y + offset);
          canvas.lineTo(s + w + leftX, y + offset);
          canvas.stroke();
      }
docs: Draws a horizontal line.
  @param canvas	the canvas to draw on
  @param leftX		the left x coordinate
  @param rightX	the right x coordindate
  @param y			the y coordinate