@Override
  public boolean onTouchEvent(MotionEvent event) {

    Point point = new Point();
    point.x = (int) event.getX();
    point.y = (int) event.getY();

    int count = 0;
    for (PieSlice slice : slices) {
      Region r = new Region();
      r.setPath(slice.getPath(), slice.getRegion());
      if (r.contains(point.x, point.y) && event.getAction() == MotionEvent.ACTION_DOWN) {
        indexSelected = count;
      } else if (event.getAction() == MotionEvent.ACTION_UP) {
        if (r.contains(point.x, point.y) && listener != null) {
          if (indexSelected > -1) {
            listener.onClick(indexSelected);
          }
          indexSelected = -1;
        }
      }
      count++;
    }

    if (event.getAction() == MotionEvent.ACTION_DOWN
        || event.getAction() == MotionEvent.ACTION_UP) {
      postInvalidate();
    }

    return true;
  }
  public void onDraw(Canvas canvas) {
    canvas.drawColor(Color.TRANSPARENT);
    paint.reset();
    paint.setAntiAlias(true);
    float midX, midY, radius, innerRadius;
    path.reset();

    float currentAngle = 270;
    float currentSweep;
    int totalValue = 0;
    float padding = 2;

    midX = getWidth() / 2;
    midY = getHeight() / 2;
    if (midX < midY) {
      radius = midX;
    } else {
      radius = midY;
    }
    radius -= padding;
    innerRadius = radius - thickness;

    for (PieSlice slice : slices) {
      totalValue += slice.getValue();
    }

    int count = 0;
    for (PieSlice slice : slices) {
      Path p = new Path();
      paint.setColor(slice.getColor());
      currentSweep = (slice.getValue() / totalValue) * (360);
      p.arcTo(
          new RectF(midX - radius, midY - radius, midX + radius, midY + radius),
          currentAngle + padding,
          currentSweep - padding);
      p.arcTo(
          new RectF(midX - innerRadius, midY - innerRadius, midX + innerRadius, midY + innerRadius),
          (currentAngle + padding) + (currentSweep - padding),
          -(currentSweep - padding));
      p.close();

      slice.setPath(p);
      slice.setRegion(
          new Region(
              (int) (midX - radius),
              (int) (midY - radius),
              (int) (midX + radius),
              (int) (midY + radius)));
      canvas.drawPath(p, paint);

      if (indexSelected == count && listener != null) {
        path.reset();
        paint.setColor(slice.getColor());
        paint.setColor(Color.parseColor("#33B5E5"));
        paint.setAlpha(100);

        if (slices.size() > 1) {
          path.arcTo(
              new RectF(
                  midX - radius - (padding * 2),
                  midY - radius - (padding * 2),
                  midX + radius + (padding * 2),
                  midY + radius + (padding * 2)),
              currentAngle,
              currentSweep + padding);
          path.arcTo(
              new RectF(
                  midX - innerRadius + (padding * 2),
                  midY - innerRadius + (padding * 2),
                  midX + innerRadius - (padding * 2),
                  midY + innerRadius - (padding * 2)),
              currentAngle + currentSweep + padding,
              -(currentSweep + padding));
          path.close();
        } else {
          path.addCircle(midX, midY, radius + padding, Direction.CW);
        }

        canvas.drawPath(path, paint);
        paint.setAlpha(255);
      }

      currentAngle = currentAngle + currentSweep;

      count++;
    }
  }