tempo_map_change.h

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/*
    Copyright (C) 2022 Paul Davis
 
    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.
*/
 
#include <string>
 
#include "temporal/tempo.h"
 
#include "public_editor.h"
 
/* RAII for tempo map edits. This object manages both Tempo map RCU stuff, plus
 * reversible command state, removing the need for repeated boilerplate at each
 * map edit site.
 *
 * One complication: GUI tempo map markers are all reassociated with the
 * relevant points of the write-copy of the map during ::begin() (typically
 * called in the constructor, unless it's begin argument is false). You must
 * delay getting a reference on a point to edit until after the TempoMapChange
 * object has called begin() (i.e. has been constructed), otherwise the
 * reference will point to the "old" copy of the map.
 */
 
class TempoMapChange {
  public:
        TempoMapChange (PublicEditor& e, std::string const & name, bool update_on_commit = true, bool begin = true);
        ~TempoMapChange ();
 
        void begin ();
        void abort ();
        void use_new_map (Temporal::TempoMap::WritableSharedPtr);
 
        Temporal::TempoMap& map() const { return *writable_map.get(); }
 
  private:
        PublicEditor& editor;
        Temporal::TempoMap::WritableSharedPtr writable_map;
        std::string name;
        bool aborted;
        bool begun;
        bool update_on_commit;
        XMLNode* before;
};