gwt cell table dynamic columns - sorting

Question

You can represent your \"rows\" as List instances, you have to change your parameterization from String to List in your Grid, Column and data provider

Answer 1

Here is the data grid code

indexedColumn.setSortable(true);
sortHandler.setComparator((Column) indexedColumn, (Comparator) indexedColumn.getComparator(true));

Here is the actual class

    public class IndexedColumn extends Column, String>
{
   private Comparator> forwardComparator;
   private Comparator> reverseComparator;
   private final int index;

   public IndexedColumn(int index)
   {
      super(new TextCell());
      this.index = index;
   }

   @Override
   public String getValue(List object)
   {
      return object.get(index);
   }

   public Comparator> getComparator(final boolean reverse)
   {
      if (!reverse && forwardComparator != null)
      {
         return forwardComparator;
      }
      if (reverse && reverseComparator != null)
      {
         return reverseComparator;
      }
      Comparator> comparator = new Comparator>()
      {
         public int compare(List o1, List o2)
         {
            if (o1 == null && o2 == null)
            {
               return 0;
            }
            else if (o1 == null)
            {
               return reverse ? 1 : -1;
            }
            else if (o2 == null)
            {
               return reverse ? -1 : 1;
            }

            // Compare the column value.
            String c1 = getValue(o1);
            String c2 = getValue(o2);
            if (c1 == null && c2 == null)
            {
               return 0;
            }
            else if (c1 == null)
            {
               return reverse ? 1 : -1;
            }
            else if (c2 == null)
            {
               return reverse ? -1 : 1;
            }
            int comparison = ((String) c1).compareTo(c2);
            return reverse ? -comparison : comparison;
         }
      };

      if (reverse)
      {
         reverseComparator = comparator;
      }
      else
      {
         forwardComparator = comparator;
      }
      return comparator;
   }

}