private int getItemIndexUnderCursor(Point point) {
          if (point.x < myPadding.left || point.y < myPadding.top) return -1;
          int x = xVisibleToGrid(point.x), y = yVisibleToGrid(point.y);
          if (x >= myItemsPerRow || point.x > xGridToVisible(x) + myCellSize.width || point.y > yGridToVisible(y) + myCellSize.height) {
            return -1;
          }
          int index = myItemsPerRow * y + x;
          return index >= 0 && index < myCategory.getEmoji().size() ? index : -1;
        }
private int getItemIndexUnderCursor(Point point)