A low-level event which indicates that a container's contents changed because a component was added
or removed. Container events are provided for notification purposes ONLY; The AWT will automatically handle changes to the containers contents internally so that the program works properly regardless of whether the program is receiving these events or not. This low-level event is generated by a container object (such as a Panel) when a component is added to it or removed from it. The event is passed to every ContainerListener or ContainerAdapter object which registered to receive such events using the component's addContainerListener method. (ContainerAdapter objects implement the ContainerListener interface.) Each such listener object gets this ContainerEvent when the event occurs.
An unspecified behavior will be caused if the id parameter of any particular ContainerEvent instance is not in the range from CONTAINER_FIRST to CONTAINER_LAST. @see ContainerAdapter @see ContainerListener @see Tutorial: Writing a Container Listener @author Tim Prinzing @author Amy Fowler @since 1.1