public class DialogRegistry
{
   SparseArray<IDialogProtocol> idsToDialogs
                     = new SparseArray();
                     
   public void registerDialog(IDialogProtocol dialog)
   {
      idsToDialogs.put(dialog.getDialogId(),dialog);
   }

   public Dialog create(int id)
   {
      IDialogProtocol dp = idsToDialogs.get(id);
      if (dp == null) return null;
      return dp.create();
   }

   public void prepare(Dialog dialog, int id)
   {
      IDialogProtocol dp = idsToDialogs.get(id);
      if (dp == null)
      {
         throw new RuntimeException("Dialog id is not registered:" + id);
      }
      dp.prepare(dialog);
   }
}