// action.hpp -- the base class for actions
//
// Written by Frederic Bouvier, started May 2002.
//
// Copyright (C) 2002  Frederic Bouvier - fredb@users.sourceforge.net
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; either version 2 of the
// License, or (at your option) any later version.
//
// This program 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
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
//
// $Id: action.hpp,v 1.8 2002/07/14 23:05:45 fredb Exp $

#ifndef _action_hpp_
#define _action_hpp_

#include <string>

class SGPropertyNode;
class FGSD_MainWindow;

class FGSD_ActionID {
   public:
      FGSD_ActionID();
      bool operator==( const FGSD_ActionID &right ) const;

   private:
      static long _currentId;
      long _id;
};

class FGSD_Action {
   public:
      FGSD_Action() : _isUndoable( true ) {}
      virtual ~FGSD_Action() {}

      virtual bool undo() = 0;
      virtual bool redo( bool __step = false ) = 0;
      virtual std::string name() const = 0;
      virtual std::string description() const = 0;
      virtual bool combine( FGSD_Action *__action );
      virtual FGSD_ActionID type() const = 0;
      virtual void *convertTo( FGSD_ActionID __id ) = 0;
      virtual FGSD_Action *clone() const = 0;
      virtual bool getPosition( bool undo, double &lon, double &lat ) const;
      virtual bool savable() const;

      virtual bool save( const char *__project, SGPropertyNode *__node ) = 0;
      virtual bool load( const char *__project, SGPropertyNode *__node ) = 0;
      virtual size_t weight( SGPropertyNode *__node );
      virtual double timeoutForCombine() const;

      bool isUndoable() const;

   protected:
      void step( size_t n ) const;
      bool _isUndoable;

      static FGSD_MainWindow *_mainWindow;
      static void (*_step)( size_t, void * );
      friend class FGSD_MainWindow;
      friend class FGSD_ActionManager;
};

inline
bool FGSD_Action::isUndoable() const
{
   return _isUndoable;
}

#endif