targetStyleName = "x-border-layout-ct";
componentStyleName = "x-border-panel";
monitorResize = true;
collapseListener = new Listener<ComponentEvent>() {
public void handleEvent(ComponentEvent e) {
EventType type = e.getType();
if (type == Events.BeforeCollapse) {
e.setCancelled(true);
onCollapse(e.<ContentPanel> getComponent());
} else if (type == Events.BeforeExpand) {
e.setCancelled(true);