// hooking up a custom cell renderer
// given TableCellRenderer renderer, JTable jTable and Class renderClass
if ( renderClass == Object.class || renderClass == null )
   {
   /* ignore renderClass and install on each column */
   TableColumnModel tm = jTable.getColumnModel();
   int columns = tm.getColumnCount();
   for ( int i=0; i<columns; i++ )
      {
      TableColumn tc = tm.getColumn( i );
      tc.setCellRenderer( renderer );
      }
   }
else
   {
   /* install on just renderClass */
   jTable.setDefaultRenderer( renderClass, renderer );
   }