File indexing completed on 2024-05-12 15:27:00

 /***************************************************************************
     File                 : PropertyChangeCommand.h
     Project              : SciDAVis / LabPlot
     --------------------------------------------------------------------
     Copyright            : (C) 2010 Knut Franke
     Email (use @ for *)  : Knut.Franke*gmx.net
     Description          : Generic undo command changing a single variable.
 
  ***************************************************************************/
 
 /***************************************************************************
  *                                                                         *
  *  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                                           *
  *                                                                         *
  ***************************************************************************/
 
 #ifndef PROPERTY_CHANGE_COMMAND_H
 #define PROPERTY_CHANGE_COMMAND_H
 
 #include <QUndoCommand>
 
 /**
  * \class PropertyChangeCommand
  * \brief Generic undo command changing a single variable.
  *
  * Given a pointer to a variable (usually a member of the class instantiating the command, or of
  * its private implementation class) and a new value, assigns the value to the variable. A backup
  * of the old value is made, so that undo/redo can switch back and forth between the two values.
  * The value type needs to support copy construction and assignment.
  */
 
 template<class T> class PropertyChangeCommand : public QUndoCommand {
 
 public:
     PropertyChangeCommand(const QString &text, T *property, const T &new_value)
         : m_property(property), m_other_value(new_value) {
             setText(text);
         }
 
     void redo() override {
         T tmp = *m_property;
         *m_property = m_other_value;
         m_other_value = tmp;
     }
 
     void undo() override {
         redo();
     }
 
     int id() const override {
         return reinterpret_cast<std::intptr_t>(m_property);
     }
 
     bool mergeWith(const QUndoCommand* other) override {
         if (other->id() != id())
             return false;
 
         if (std::is_same<T, bool>::value)
             *m_property = *(static_cast<const PropertyChangeCommand*>(other)->m_property);
         else
             *m_property += *(static_cast<const PropertyChangeCommand*>(other)->m_property);
 
         return true;
     }
 
     T *m_property;
 
 private:
     T m_other_value;
 };
 
 #endif // ifndef PROPERTY_CHANGE_COMMAND_H