Using the classes available in this package, hierarchical data structures can be viewed interactively. The GUI side is based on a Swing JTree component, and the underlying data model is supplied by classes conforming to the package's DataNode interface.

Adding knowledge of a new type of hierarchical data is done by providing a new class implementating DataNode. Such new DataNode implementors must be able to do the following:

• supply their children on request (though not necessarily know what type of node each child represents) - this should be done by using a DataNodeFactory
• provide a textual and iconic representation of itself
• possible provide a JComponent giving fuller details of itself
• have one or more constructors based on fairly generic objects such as String, File, other types of DataNode