undo-stack-observer.h revision 535b1596de71acb960a629b0f34f0d2171a34348
/**
* Undo stack observer interface
*
* Observes undo, redo, and undo log commit events.
*
* Authors:
* David Yip <yipdw@rose-hulman.edu>
*
* Copyright (c) 2005 Authors
*
* Released under GNU GPL, read the file 'COPYING' for more information
*/
#ifndef __UNDO_COMMIT_OBSERVER_H__
#define __UNDO_COMMIT_OBSERVER_H__
namespace Inkscape {
namespace XML {
class Event;
}
/**
* Observes changes made to the undo and redo stacks.
*
* More specifically, an UndoStackObserver is a class that receives notifications when
* any of the following events occur:
* <ul>
* <li>A change is committed to the undo stack.</li>
* <li>An undo action is made.</li>
* <li>A redo action is made.</li>
* </ul>
*
* UndoStackObservers should not be used on their own. Instead, they should be registered
* with a CompositeUndoStackObserver.
*/
class UndoStackObserver {
public:
UndoStackObserver() { }
virtual ~UndoStackObserver() { }
/**
* Triggered when the user issues an undo command.
*
* \param log Pointer to an XML::Event describing the undone event.
*/
virtual void notifyUndoEvent(XML::Event* log) = 0;
/**
* Triggered when the user issues a redo command.
*
* \param log Pointer to an XML::Event describing the redone event.
*/
virtual void notifyRedoEvent(XML::Event* log) = 0;
/**
* Triggered when a set of transactions is committed to the undo log.
*
* \param log Pointer to an XML::Event describing the committed events.
*/
virtual void notifyUndoCommitEvent(XML::Event* log) = 0;
};
}
#endif