/* This file is part of the KDE libraries
   Copyright (C) 2001 Christoph Cullmann <cullmann@kde.org>

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License version 2 as published by the Free Software Foundation.

   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public License
   along with this library; see the file COPYING.LIB.  If not, write to
   the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
   Boston, MA 02110-1301, USA.
*/

#ifndef __ktexteditor_undointerface_h__
#define __ktexteditor_undointerface_h__

#include <kdelibs_export.h>

class QCString;

namespace KTextEditor
{

/**
*  This is an interface to undo functionality of a Document.
*/
class KTEXTEDITOR_EXPORT UndoInterface
{
  friend class PrivateUndoInterface;

  public:
    UndoInterface ();
    virtual ~UndoInterface ();

    unsigned int undoInterfaceNumber () const;
    
  protected:  
    void setUndoInterfaceDCOPSuffix (const QCString &suffix); 

  //
  // slots !!!
  //
  public:
    virtual void undo () = 0;

    virtual void redo () = 0;

    virtual void clearUndo () = 0;

    virtual void clearRedo () = 0;

    virtual unsigned int undoCount () const = 0;

    virtual unsigned int redoCount () const = 0;

    /**
      returns the maximum of undo steps possible, 0 means no limit !
     */
    virtual unsigned int undoSteps () const = 0;

    virtual void setUndoSteps ( unsigned int steps ) = 0;

  //
  // signals !!!
  //
  public:
    virtual void undoChanged () = 0;

  private:
    class PrivateUndoInterface *d;
    static unsigned int globalUndoInterfaceNumber;
    unsigned int myUndoInterfaceNumber;
};

KTEXTEDITOR_EXPORT UndoInterface *undoInterface (class Document *doc);

}

#endif
