DesktopManager objects are owned by a JDesktopPane object. They are responsible for implementing L&F specific behaviors for the JDesktopPane. JInternalFrame implementations should delegate specific behaviors to the DesktopManager. For instance, if a JInternalFrame was asked to iconify, it should try: 
    getDesktopPane().getDesktopManager().iconifyFrame(frame);
This delegation allows each L&F to provide custom behaviors for desktop-specific actions. (For example, how and where the internal frame's icon would appear.)

This class provides a policy for the various JInternalFrame methods, it is not meant to be called directly rather the various JInternalFrame methods will call into the DesktopManager.

@version
1.15 12/19/03
@author
David Kloba
See Also
JDesktopPane , JInternalFrame , JInternalFrame.JDesktopIcon
Generally, indicate that this frame has focus. This is usually called after the JInternalFrame's IS_SELECTED_PROPERTY has been set to true.
This method is normally called when the user has indicated that they will begin dragging a component around. This method should be called prior to any dragFrame() calls to allow the DesktopManager to prepare any necessary state. Normally f will be a JInternalFrame.
This methods is normally called when the user has indicated that they will begin resizing the frame. This method should be called prior to any resizeFrame() calls to allow the DesktopManager to prepare any necessary state. Normally f will be a JInternalFrame.
Generally, this call should remove the frame from it's parent.
Generally, indicate that this frame has lost focus. This is usually called after the JInternalFrame's IS_SELECTED_PROPERTY has been set to false.
Generally, remove any iconic representation that is present and restore the frame to it's original size and location.
The user has moved the frame. Calls to this method will be preceded by calls to beginDraggingFrame(). Normally f will be a JInternalFrame.
This method signals the end of the dragging session. Any state maintained by the DesktopManager can be removed here. Normally f will be a JInternalFrame.
This method signals the end of the resize session. Any state maintained by the DesktopManager can be removed here. Normally f will be a JInternalFrame.
Generally, remove this frame from it's parent and add an iconic representation.
Generally, the frame should be resized to match it's parents bounds.
Generally, this indicates that the frame should be restored to it's size and position prior to a maximizeFrame() call.
If possible, display this frame in an appropriate location. Normally, this is not called, as the creator of the JInternalFrame will add the frame to the appropriate parent.
The user has resized the component. Calls to this method will be preceded by calls to beginResizingFrame(). Normally f will be a JInternalFrame.
This is a primitive reshape method.