code: public int findHeaderPositionUnder(int x, int y) {
          for (int i = 0; i < mHeaderRects.size(); i++) {
              Rect rect = mHeaderRects.get(mHeaderRects.keyAt(i));
              if (rect.contains(x, y)) {
                  return mHeaderRects.keyAt(i);
              }
          }
          return -1;
      }
docs: Gets the position of the header under the specified (x, y) coordinates.
  
  @param x x-coordinate
  @param y y-coordinate
  @return position of header, or -1 if not found