/**
  * The graphical representation of the legend shape.
  *
  * @param canvas the canvas to paint to
  * @param renderer the series renderer
  * @param x the x value of the point the shape should be drawn at
  * @param y the y value of the point the shape should be drawn at
  * @param seriesIndex the series index
  * @param paint the paint to be used for drawing
  */
 public void drawLegendShape(
     Canvas canvas,
     SimpleSeriesRenderer renderer,
     float x,
     float y,
     int seriesIndex,
     Paint paint) {
   canvas.drawLine(x, y, x + SHAPE_WIDTH, y, paint);
   if (isRenderPoints(renderer)) {
     pointsChart.drawLegendShape(canvas, renderer, x + 5, y, seriesIndex, paint);
   }
 }
  /**
   * The graphical representation of a series.
   *
   * @param canvas the canvas to paint to
   * @param paint the paint to be used for drawing
   * @param points the array of points to be used for drawing the series
   * @param seriesRenderer the series renderer
   * @param yAxisValue the minimum value of the y axis
   * @param seriesIndex the index of the series currently being drawn
   * @param startIndex the start index of the rendering points
   */
  @Override
  public void drawSeries(
      Canvas canvas,
      Paint paint,
      List<Float> points,
      XYSeriesRenderer renderer,
      float yAxisValue,
      int seriesIndex,
      int startIndex) {
    float lineWidth = paint.getStrokeWidth();
    paint.setStrokeWidth(renderer.getLineWidth());
    final FillOutsideLine[] fillOutsideLine = renderer.getFillOutsideLine();

    for (FillOutsideLine fill : fillOutsideLine) {
      if (fill.getType() != FillOutsideLine.Type.NONE) {
        paint.setColor(fill.getColor());
        // TODO: find a way to do area charts without duplicating data
        List<Float> fillPoints = new ArrayList<Float>();
        int[] range = fill.getFillRange();
        if (range == null) {
          fillPoints.addAll(points);
        } else {
          if (points.size() > range[0] * 2 && points.size() > range[1] * 2) {
            fillPoints.addAll(points.subList(range[0] * 2, range[1] * 2));
          }
        }

        final float referencePoint;
        switch (fill.getType()) {
          case BOUNDS_ALL:
            referencePoint = yAxisValue;
            break;
          case BOUNDS_BELOW:
            referencePoint = yAxisValue;
            break;
          case BOUNDS_ABOVE:
            referencePoint = yAxisValue;
            break;
          case BELOW:
            referencePoint = canvas.getHeight();
            break;
          case ABOVE:
            referencePoint = 0;
            break;
          default:
            throw new RuntimeException(
                "You have added a new type of filling but have not implemented.");
        }
        if (fill.getType() == FillOutsideLine.Type.BOUNDS_ABOVE
            || fill.getType() == FillOutsideLine.Type.BOUNDS_BELOW) {
          List<Float> boundsPoints = new ArrayList<Float>();
          boolean add = false;
          int length = fillPoints.size();
          if (length > 0
                  && fill.getType() == FillOutsideLine.Type.BOUNDS_ABOVE
                  && fillPoints.get(1) < referencePoint
              || fill.getType() == FillOutsideLine.Type.BOUNDS_BELOW
                  && fillPoints.get(1) > referencePoint) {
            boundsPoints.add(fillPoints.get(0));
            boundsPoints.add(fillPoints.get(1));
            add = true;
          }

          for (int i = 3; i < length; i += 2) {
            float prevValue = fillPoints.get(i - 2);
            float value = fillPoints.get(i);

            if (prevValue < referencePoint && value > referencePoint
                || prevValue > referencePoint && value < referencePoint) {
              float prevX = fillPoints.get(i - 3);
              float x = fillPoints.get(i - 1);
              boundsPoints.add(
                  prevX + (x - prevX) * (referencePoint - prevValue) / (value - prevValue));
              boundsPoints.add(referencePoint);
              if (fill.getType() == FillOutsideLine.Type.BOUNDS_ABOVE && value > referencePoint
                  || fill.getType() == FillOutsideLine.Type.BOUNDS_BELOW
                      && value < referencePoint) {
                i += 2;
                add = false;
              } else {
                boundsPoints.add(x);
                boundsPoints.add(value);
                add = true;
              }
            } else {
              if (add
                  || fill.getType() == FillOutsideLine.Type.BOUNDS_ABOVE && value < referencePoint
                  || fill.getType() == FillOutsideLine.Type.BOUNDS_BELOW
                      && value > referencePoint) {
                boundsPoints.add(fillPoints.get(i - 1));
                boundsPoints.add(value);
              }
            }
          }

          fillPoints.clear();
          fillPoints.addAll(boundsPoints);
        }
        int length = fillPoints.size();
        if (length > 0) {
          fillPoints.set(0, fillPoints.get(0) + 1);
          fillPoints.add(fillPoints.get(length - 2));
          fillPoints.add(referencePoint);
          fillPoints.add(fillPoints.get(0));
          fillPoints.add(fillPoints.get(length + 1));
          for (int i = 0; i < length + 4; i += 2) {
            if (fillPoints.get(i + 1) < 0) {
              fillPoints.set(i + 1, 0f);
            }
          }

          paint.setStyle(Style.FILL);
          drawPath(canvas, fillPoints, paint, true);
        }
      }
    }
    paint.setColor(renderer.getColor());
    paint.setStyle(Style.STROKE);
    drawPath(canvas, points, paint, false);
    paint.setStrokeWidth(lineWidth);
  }