Framework
components often need to maintain lists of objects. For this purpose, the
framework provides a generic object list of type ObjectList. This
class manages a list of references to objects of generic type Object.
Basically, it maintains a list of references and offers methods to add
and remove references and to iterate through the references in the list.
Framework
components that use object lists normally need to see the list as a container
for objects (or references to objects) of a specific type. If they used
directly ObjectList they would therefore have to perform potentially
dangerous cast operations. In order to aboid this, wrapper classes are
offered that extend ObjectList in a type-safe manner. Class ObjectList
has a protected constructor and therefore cannot be directly instantiated
by users.