StateEdit

Class Overview

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.

      // 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!

Summary

[Expand] Inherited Constants
From class javax.swing.undo.AbstractUndoableEdit String RedoName String returned by getRedoPresentationName; as of Java 2 platform v1.3.1 this field is no longer used. String UndoName String returned by getUndoPresentationName; as of Java 2 platform v1.3.1 this field is no longer used.

[Expand] Inherited Methods
From class javax.swing.undo.AbstractUndoableEdit boolean addEdit(UndoableEdit anEdit) This default implementation returns false. boolean canRedo() Returns true if this edit is alive and hasBeenDone is false. boolean canUndo() Returns true if this edit is alive and hasBeenDone is true. void die() Sets alive to false. String getPresentationName() This default implementation returns "". String getRedoPresentationName() Retreives the value from the defaults table with key AbstractUndoableEdit.redoText and returns that value followed by a space, followed by getPresentationName. String getUndoPresentationName() Retreives the value from the defaults table with key AbstractUndoableEdit.undoText and returns that value followed by a space, followed by getPresentationName. boolean isSignificant() This default implementation returns true. void redo() Throws CannotRedoException if canRedo returns false. boolean replaceEdit(UndoableEdit anEdit) This default implementation returns false. String toString() Returns a string that displays and identifies this object's properties. void undo() Throws CannotUndoException if canUndo returns false.
From class java.lang.Object Object clone() Creates and returns a copy of this object. boolean equals(Object obj) Indicates whether some other object is "equal to" this one. void finalize() Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. final Class<?> getClass() Returns the runtime class of this Object. int hashCode() Returns a hash code value for the object. final void notify() Wakes up a single thread that is waiting on this object's monitor. final void notifyAll() Wakes up all threads that are waiting on this object's monitor. String toString() Returns a string representation of the object. final void wait() Causes the current thread to wait until another thread invokes the notify() method or the notifyAll() method for this object. final void wait(long timeout, int nanos) Causes the current thread to wait until another thread invokes the notify() method or the notifyAll() method for this object, or some other thread interrupts the current thread, or a certain amount of real time has elapsed. final void wait(long timeout) Causes the current thread to wait until either another thread invokes the notify() method or the notifyAll() method for this object, or a specified amount of time has elapsed.
From interface javax.swing.undo.UndoableEdit abstract boolean addEdit(UndoableEdit anEdit) Adds an UndoableEdit to this UndoableEdit. abstract boolean canRedo() Returns true if this edit may be redone. abstract boolean canUndo() Returns true if this edit may be undone. abstract void die() Informs the edit that it should no longer be used. abstract String getPresentationName() Returns a localized, human-readable description of this edit, suitable for use in a change log, for example. abstract String getRedoPresentationName() Returns a localized, human-readable description of the redoable form of this edit, suitable for use as a Redo menu item, for example. abstract String getUndoPresentationName() Returns a localized, human-readable description of the undoable form of this edit, suitable for use as an Undo menu item, for example. abstract boolean isSignificant() Returns true if this edit is considered significant. abstract void redo() Re-applies the edit. abstract boolean replaceEdit(UndoableEdit anEdit) Returns true if this UndoableEdit should replace anEdit. abstract void undo() Undo the edit.