The org.zkoss.zk.ui.util.DesktopInit interface
From Documentation
Listener:
org.zkoss.zk.ui.util.DesktopInit
A listener could implement DesktopInit to initialize a new desktop.
When ZK Loader created a new desktop, it invokes the init method of this interface such that developers could plug the application-specific codes to initialize a desktop.
A developer can prevent a desktop from being created by throwing an exception in the init method.