The org.zkoss.zk.ui.util.UiLifeCycle interface

Listener:

org.zkoss.zk.ui.util.UiLifeCycle

A listener could implement UiLifeCycle to handle something depending on the life cycle of UI, such as attaching a component to a page, moving a component and so on.

Instantiation: For better performance, a single instance of the given class is instantiated when registered. It is then shared in the whole application. Thus, the implementation must be thread safe.