What is "jdesktoppane"
You create objects of JInternalFrame and adds them to the JDesktopPane, that by extending from JLayeredPane, makes you able to manage potentially overlapping internal frames.
It also maintains a reference to an instance of DesktopManager, which is defined by the user interface class for the current appearance(Look and Feel). Note that JDesktopPane does not support edges.
This class is normally used as the "parent" of Jinternalframes, to provide a pluggable object of DesktopManager to them. The implementation of installUI specific to the Look And Feel is responsible for properly configuring the desktopManager variable.
When the "father" of a JInternalFrame is a JDesktopPane, it should delegate most of its behavior to the desktopManager(closure, resizing, etc).
