AjaxFallbackLink to Show/Hide a checkGroup problem...

[smallufo]

Hi
I want to use an AjaxFallbackLink  to show/hide a checkGroup , but I can
only "hide" it , cannot "re-show" it...
I did     checkGroup.setRenderBodyOnly(false);
and     listView.setReuseItems(true);
But still can still only hide the checkGroup , cannot make it re-appear...

Can somebody help me checking the code , thanks a lot.


    List<Planet> list = Arrays.asList(Planet.values);
    final CheckGroup checkGroup = new CheckGroup("checkGroup" , list);
    checkGroup.setRenderBodyOnly(false);
    checkGroup.setOutputMarkupId(true);
    add(checkGroup);

    ListView listView = new ListView("list", list )
    {
      @Override
      protected void populateItem(ListItem item)
      {
        Planet planet = (Planet) item.getModelObject();
        item.add(new PointShownCheckBox("check" , displayables , planet));
        item.add(new Label("name" , planet.getName()));
      }
    };
    listView.setReuseItems(true);
    checkGroup.add(listView);


    collapseExpandStarsLink = new
AjaxFallbackLink("collapseExpandStarsLink")
    {
      @Override
      public void onClick(AjaxRequestTarget target)
      {
        if(checkGroup.isVisible())
          target.addComponent(checkGroup.setVisible(false));
        else
          target.addComponent(checkGroup.setVisible(true));
      }
    };
    add(collapseExpandStarsLink);