private @Nullable Couple<Integer> pointToCellCoords(Point p) {
      int x = p.x;
      int y = p.y;

      final Insets i = getInsets();
      final Dimension d = getSize();

      final int left = i.left + (d.width - i.left - i.right - WIDTH) / 2;
      final int top = i.top + (d.height - i.top - i.bottom - HEIGHT) / 2;

      int col = (x - left - 2) / 31;
      col = Math.min(col, 9);
      int row = (y - top - 2) / 31;
      row = Math.min(row, 1);

      return row >= 0 && col >= 0 ? Couple.of(row, col) : null;
    }
private @Nullable Couple<Integer> pointToCellCoords(Point p)