code: public static void bindStateStyle (Value<Boolean> value, final String onStyle,
                                         final String offStyle, final Widget... targets)
      {
          value.addListenerAndTrigger(new Value.Listener<Boolean>() {
              public void valueChanged (Boolean value) {
                  String add, remove;
                  if (value) {
                      remove = offStyle;
                      add = onStyle;
                  } else {
                      remove = onStyle;
                      add = offStyle;
                  }
                  for (Widget target : targets) {
                      if (remove != null) {
                          target.removeStyleName(remove);
                      }
                      if (add != null) {
                          target.addStyleName(add);
                      }
                  }
              }
          });
      }
docs: Configures either `onStyle` or `offStyle` on the supplied target widgets depending on the
  state of the supplied boolean `value`.
  
  @param onStyle the style name to be applied when the value is true, or null.
  @param offStyle the style name to be applied when the value is false, or null.