Classes which implement this interface provide methods
that deal with the expanding and collapsing of ExpandItems.
After creating an instance of a class that implements
this interface it can be added to a ExpandBar
control using the addExpandListener method and
removed using the removeExpandListener method.
When a item of the ExpandBar is expanded or
collapsed, the appropriate method will be invoked.
ExpandItems.After creating an instance of a class that implements this interface it can be added to a
ExpandBarcontrol using theaddExpandListenermethod and removed using theremoveExpandListenermethod. When a item of theExpandBaris expanded or collapsed, the appropriate method will be invoked.