vcommand.h

/* This file is part of the KDE project
   Copyright (C) 2001, The Karbon Developers
   Copyright (C) 2002, The Karbon Developers
 
   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.
 
   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 __VCOMMAND_H__
#define __VCOMMAND_H__
 
 
//#include <assert.h>
 
#include <tqobject.h>
#include <tqptrlist.h>
 
#include "vvisitor.h"
 
class VDocument;
class KarbonPart;
class TDEAction;

class VCommand : public VVisitor
{
public:
    VCommand( VDocument* doc, const TQString& name, const TQString& icon = "14_action" )
            : m_document( doc ), m_name( name ), m_icon( icon )
    {
// A crash because of an assert() is not much better than an crash because of a null
// pointer. Allowing null pointers allows the usage of the vitors ascpect of a VCommand.
//      assert( doc );
    }

    virtual ~VCommand() {}

    virtual void execute() = 0;

    virtual void unexecute() {}

    virtual bool changesSelection() const { return false; }

    TQString name() const
    {
        return m_name;
    }
 
    void setName( const TQString& name )
    {
        m_name = name;
    }

    TQString icon() const
    {
        return m_icon;
    }

    VDocument* document() const
    {
        return m_document;
    }
 
private:
    VDocument* m_document;
 
    TQString m_name;
    TQString m_icon;
};

class VCommandHistory : public TQObject
{
    TQ_OBJECT
  
 
public:
    VCommandHistory( KarbonPart* part );
    
    ~VCommandHistory();

    void clear();

    void addCommand( VCommand* command, bool execute = true );
 
 
    // limits
    unsigned int undoLimit() const
    {
        return m_undoLimit;
    }

    void setUndoLimit( unsigned int limit );

    unsigned int redoLimit() const
    {
        return m_redoLimit;
    }

    void setRedoLimit( unsigned int limit );

    const TQPtrList<VCommand>* commands() const
    {
        return & m_commands;
    }
 
public slots:
    void undo();
    
    void redo();
    
    void undo( VCommand* command );

    void redo( VCommand* command );
    
    void undoAllTo( VCommand* command );

    void redoAllTo( VCommand* command );

    void documentSaved();
 
signals:
    void historyCleared();

    void commandExecuted( VCommand* );

    void commandExecuted();

    void commandAdded( VCommand* );

    void firstCommandRemoved();

    void lastCommandRemoved();

    void documentRestored();
 
private:
    // helpers
    void clipCommands();
    void updateActions();
 
    KarbonPart *m_part;
    unsigned int m_undoLimit;
    unsigned int m_redoLimit;
    TDEAction *m_undo;
    TDEAction *m_redo;
    TQPtrList<VCommand> m_commands;
    int m_savedPos;
};
 
#endif