ExtentionManagement.add("ress.panel", new IExtension() {
@Override
public void work(HashMap<String, Object> objects) {
RessPanel ress = (RessPanel) objects.get("panel");
RessourceList list = (RessourceList) objects.get("list");
// build it
PreviewPanel preview = new PreviewPanel();
JPanel left = new JPanel(new GridLayout(1, 1));
// add it
ress.setList(new RessourceXList(list.getProject(), list.getFolder(), preview, left));
// add element
ress.removeAll();
ress.add(YFactory.createHorizontPanel(left, ress.getList(), "ressX.panel"));
ress.invalidate();