Module java.desktop

Class StateEdit

All Implemented Interfaces:
Serializable, UndoableEdit

public class StateEdit
extends AbstractUndoableEdit

StateEdit is a general edit for objects that change state. Objects being edited must conform to the StateEditable interface.

This edit class works by asking an object to store it's state in Hashtables before and after editing occurs. Upon undo or redo the object is told to restore it's state from these Hashtables.

A state edit is used as follows:
      // Create the edit during the "before" state of the object
      StateEdit newEdit = new StateEdit(myObject);
      // Modify the object
      myObject.someStateModifyingMethod();
      // "end" the edit when you are done modifying the object
      newEdit.end();
 

Note that when a StateEdit ends, it removes redundant state from the Hashtables - A state Hashtable is not guaranteed to contain all keys/values placed into it when the state is stored!

See Also:
StateEditable