org.acm.seguin.refactor.undo
Class UndoStack

java.lang.Object
  org.acm.seguin.refactor.undo.UndoStack

public class UndoStack
extends java.lang.Object

The stack of refactorings that we can undo. This stack holds all the refactorings that have occurred in the system.

This object is a singleton object because we only want one object responsible for storing the refactorings that can be undone.

Version:

$Id: UndoStack.java,v 1.6 2003/12/02 23:39:40 mikeatkinson Exp $

Author:

Chris Seguin, Mike Atkinson

Constructor Summary

UndoStack()
Constructor for the UndoStack object

Method Summary

UndoAction	add(Refactoring ref) Adds a refactoring to the undo stack.
void	delete() Deletes the undo stack
void	done() Description of the Method
static UndoStack	get() Gets the singleton undo operation
boolean	isStackEmpty() Gets the StackEmpty attribute of the UndoStack object
java.util.Iterator	list() Lists the undo actions in the stack
UndoAction	peek() Return the top option without removing it from the stack
void	setUndoAction(java.lang.Class undoer) This sets the class that holds undo actions.
void	undo() Performs an undo of the top action

Methods inherited from class java.lang.Object

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

Constructor Detail

UndoStack

public UndoStack()

Constructor for the UndoStack object

Method Detail

setUndoAction

public void setUndoAction(java.lang.Class undoer)
                   throws java.lang.IllegalArgumentException

This sets the class that holds undo actions. If not called the org.acm.seguin.refactor.undo.DefaultUndoAction class is used. This creates file backups with extensions of incrementing integers.

Parameters:

undoer - a class that implements org.acm.seguin.refactor.undo.UndoAction

Throws:

java.lang.IllegalArgumentException - if the class cannot be instantiated or does not implement UndoAction

isStackEmpty

public boolean isStackEmpty()

Gets the StackEmpty attribute of the UndoStack object

Returns:

The StackEmpty value

add

public UndoAction add(Refactoring ref)

Adds a refactoring to the undo stack. You provide the refactoring, this method provides the undo action.

Parameters:

ref - the refactoring about to be performed

Returns:

an undo action

peek

public UndoAction peek()

Return the top option without removing it from the stack

Returns:

the top object

list

public java.util.Iterator list()

Lists the undo actions in the stack

Returns:

an iterator of undo actions

undo

public void undo()

Performs an undo of the top action

done

public void done()

Description of the Method

delete

public void delete()

Deletes the undo stack

get

public static UndoStack get()

Gets the singleton undo operation

Returns:

the undo stack for the system