harmonic.mz.manager
Class UndoManager

java.lang.Object
  |
  +--harmonic.mz.manager.UndoManager

public class UndoManager

extends java.lang.Object

The manager of the undo/redo system.

The undo/redo system is based on keeping an object that holds the old state of an object that is about to be changed. Before changing the state, create the appropriate type of undo node, and add to the UndoManager. The undo node is cappable of restoring the old state if it is actavated. When the undo node is actavated, it creates another undo node that has the current state of the object (before the undo is done), and puts this in the redo list. Thus the same type of undo node is used for both undo and redo.

Method Summary

void	addActionHistoryListener(ActionHistoryListener l) Registers a listener to changes in the undo history
void	addUndo(UndoRecord ur) Add an undo to the undo stack.
void	addUndo(UndoRecord ur, UndoGroup group) Add an undo record to the given undo group
UndoMark	addUndoMark() Create a mark in undo history.
void	clearUndoBlock() Clears the current undo block, so that addUndo() will add the node directly to the undo history.
java.util.Vector	getRedoProphacy() Returns list of UndoRecords that will make redos.
int	getRedoProphacySize() Return number of items on redo stack
java.util.Vector	getUndoHistory() Returns list of UndoRecords that will make undos.
int	getUndoHistorySize() Return number of items on undo stack
void	notifyListeners() Notifies listeners
void	purgeUndo() Purge the undo stack.
void	redo() Execute the redo at the end of the redo list, and add add the corresponding undo back onto the undo list
void	removeActionHistoryListener(ActionHistoryListener l) Un-Registers a listener to changes in the undo history
void	setUndoBlock() This creates an undo group and sets an internal variable that will make addUndo() add the given undo reference to the undo group.
void	setUndoBlock(java.lang.String name)
void	undo() Execute the undo record at the top of the undo stack, and create a redo record and add to redo list.
void	undoToMark(UndoMark mark) Undo everything added after the undo mark was added.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

addActionHistoryListener

public void addActionHistoryListener(ActionHistoryListener l)

Registers a listener to changes in the undo history

removeActionHistoryListener

public void removeActionHistoryListener(ActionHistoryListener l)

Un-Registers a listener to changes in the undo history

notifyListeners

public void notifyListeners()

Notifies listeners

purgeUndo

public void purgeUndo()

Purge the undo stack.

setUndoBlock

public void setUndoBlock()

This creates an undo group and sets an internal variable that will make addUndo() add the given undo reference to the undo group. In this way a set of related changes may be stored under one undo group, even if the changers are only calling addUndo() with no known undo group.

setUndoBlock

public void setUndoBlock(java.lang.String name)

clearUndoBlock

public void clearUndoBlock()

Clears the current undo block, so that addUndo() will add the node directly to the undo history.

addUndoMark

public UndoMark addUndoMark()

Create a mark in undo history. Marks created for this purpose (internal use marks) should not appear in users list.

undoToMark

public void undoToMark(UndoMark mark)

Undo everything added after the undo mark was added.

getRedoProphacy

public java.util.Vector getRedoProphacy()

Returns list of UndoRecords that will make redos.

getUndoHistory

public java.util.Vector getUndoHistory()

Returns list of UndoRecords that will make undos.

getUndoHistorySize

public int getUndoHistorySize()

Return number of items on undo stack

getRedoProphacySize

public int getRedoProphacySize()

Return number of items on redo stack

addUndo

public void addUndo(UndoRecord ur,
                    UndoGroup group)

Add an undo record to the given undo group

addUndo

public void addUndo(UndoRecord ur)

Add an undo to the undo stack. If setUndoBlock() has been used to establish an undo scope, the undo record will be added the block, else it will be added directly to undo stack.

undo

public void undo()

Execute the undo record at the top of the undo stack, and create a redo record and add to redo list. If the undo record is a group, all contained undos are executed.

redo

public void redo()

Execute the redo at the end of the redo list, and add add the corresponding undo back onto the undo list