undo.h

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/*
 * Copyright (C) 2002 Brett Viren
 * Copyright (C) 2006-2015 Paul Davis <paul@linuxaudiosystems.com>
 * Copyright (C) 2006 Hans Fugal <hans@fugal.net>
 * Copyright (C) 2007-2009 David Robillard <d@drobilla.net>
 * Copyright (C) 2013 John Emmas <john@creativepost.co.uk>
 *
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
#pragma once
 
#include <list>
#include <map>
#include <string>
 
#include <sigc++/bind.h>
#include <sigc++/slot.h>
 
#ifndef COMPILER_MSVC
#include <sys/time.h>
#else
#include <ardourext/misc.h>
#endif
 
#include "pbd/command.h"
#include "pbd/libpbd_visibility.h"
 
namespace PBD {
 
typedef sigc::slot<void> UndoAction;
 
class LIBPBD_API UndoTransaction : public PBD::Command
{
public:
        UndoTransaction ();
        UndoTransaction (const UndoTransaction&);
        UndoTransaction& operator= (const UndoTransaction&);
        ~UndoTransaction ();
 
        void clear ();
        bool empty () const;
        bool clearing () const {
                return _clearing;
        }
 
        void add_command (PBD::Command* const);
        void remove_command (PBD::Command* const);
 
        std::list<PBD::Command*>::size_type size() const { return actions.size(); }
 
        void operator() ();
        void undo ();
        void redo ();
 
        XMLNode& get_state () const;
 
        void set_timestamp (struct timeval& t)
        {
                _timestamp = t;
        }
 
        const struct timeval& timestamp () const
        {
                return _timestamp;
        }
 
private:
        std::list<PBD::Command*> actions;
        struct timeval      _timestamp;
        bool                _clearing;
 
        void about_to_explicitly_delete ();
};
 
class LIBPBD_API UndoHistory : public PBD::ScopedConnectionList
{
public:
        UndoHistory ();
        ~UndoHistory () {}
 
        void add (UndoTransaction* ut);
        void undo (unsigned int n);
        void redo (unsigned int n);
 
        unsigned long undo_depth () const
        {
                return UndoList.size ();
        }
        unsigned long redo_depth () const
        {
                return RedoList.size ();
        }
 
        std::string next_undo () const
        {
                return (UndoList.empty () ? std::string () : UndoList.back ()->name ());
        }
        std::string next_redo () const
        {
                return (RedoList.empty () ? std::string () : RedoList.back ()->name ());
        }
 
        void clear ();
        void clear_undo ();
        void clear_redo ();
 
        /* returns all or part of the history.
         * If depth==0 it returns just the top
         * node. If depth<0, it returns everything.
         * If depth>0, it returns state for that
         * many elements of the history, or
         * the full history, whichever is smaller.
         */
 
        XMLNode& get_state (int32_t depth = 0);
        void     save_state ();
 
        void set_depth (uint32_t);
 
        PBD::Signal<void()> Changed;
        PBD::Signal<void()> BeginUndoRedo;
        PBD::Signal<void()> EndUndoRedo;
 
private:
        bool                        _clearing;
        uint32_t                    _depth;
        std::list<UndoTransaction*> UndoList;
        std::list<UndoTransaction*> RedoList;
 
        void remove (UndoTransaction*);
};
 
} /* namespace */