code: public int doSetData(Object fieldPtr, boolean bDisplayOption, int iMoveMode)
      {
          int iErrorCode = DBConstants.NORMAL_RETURN;
          boolean bSubExists = (this.getOwner().getRecord().getListener(SubFileFilter.class.getName()) != null);
          if (bSubExists)
              iErrorCode = super.doSetData(fieldPtr, bDisplayOption, iMoveMode);
          return iErrorCode;
      }
docs: Move the physical binary data to this field.
  If there is not SubFileFilter, then don't allow the field to be inited.
  @param objData the raw data to set the basefield to.
  @param bDisplayOption If true, display the change.
  @param iMoveMode The type of move being done (init/read/screen).
  @return The error code (or NORMAL_RETURN if okay).