protected void paintCells(Graphics g, int rowMin, int rowMax, int colMin, int colMax) {
   for (int row = rowMin; row <= rowMax; row++) {
     for (int column = colMin; column <= colMax; column++) {
       /* Paint cell if it is atomic */
       if (!grid.isCellSpan(row, column)) {
         Rectangle cellBounds = grid.getCellBounds(row, column);
         paintCell(g, cellBounds, row, column);
       }
     }
   }
 }