code: def setPageSize( self, pageSize ):
          
          if self._pageSize == pageSize:
              return
          
          self._pageSize = pageSize
          
          # update the display size
          ssize = nativestring(pageSize)
          if ( ssize == '0' ):
              ssize = ''
          
          self._pageSizeCombo.blockSignals(True)
          index = self._pageSizeCombo.findText(ssize)
          self._pageSizeCombo.setCurrentIndex(index)
          self._pageSizeCombo.blockSignals(False)
docs: Sets the number of items that should be visible in a page.  Setting the
          value to 0 will use all sizes
          
          :return     <int>