This class enables one to store an entry in the defaults table that's constructed each time it's looked up with one of the getXXX(key) methods.

  This class enables one to store an entry in the defaults
table that's constructed each time it's looked up with one of
the getXXX(key) methods. Here's an example of
an ActiveValue that constructs a
DefaultListCellRenderer:

  Object cellRendererActiveValue = new UIDefaults.ActiveValue() {
      public Object createValue(UIDefaults table) {
          return new DefaultListCellRenderer();
      }
  };

  uiDefaultsTable.put("MyRenderer", cellRendererActiveValue);