File indexing completed on 2024-05-05 03:56:42

 /*
     SPDX-FileCopyrightText: 2010 Klarälvdalens Datakonsult AB, a KDAB Group company <info@kdab.net>
     SPDX-FileContributor: Stephen Kelly <stephen@kdab.com>
     SPDX-FileCopyrightText: 2016 Ableton AG <info@ableton.com>
     SPDX-FileContributor: Stephen Kelly <stephen.kelly@ableton.com>
 
     SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
 #ifndef KMODELINDEXPROXYMAPPER_H
 #define KMODELINDEXPROXYMAPPER_H
 
 #include <QObject>
 
 #include "kitemmodels_export.h"
 
 #include <memory>
 
 class QAbstractItemModel;
 class QModelIndex;
 class QItemSelection;
 class KModelIndexProxyMapperPrivate;
 
 /**
  * @class KModelIndexProxyMapper kmodelindexproxymapper.h KModelIndexProxyMapper
  *
  * @brief This class facilitates easy mapping of indexes and selections through proxy models.
  *
  * In a complex system of proxy models there can be a need to map indexes and selections between them,
  * and sometimes to do so without knowledge of the path from one model to another.
  *
  * For example,
  *
  * @verbatim
  *     Root model
  *         |
  *       /    \
  *   Proxy 1   Proxy 3
  *      |       |
  *   Proxy 2   Proxy 4
  * @endverbatim
  *
  * If there is a need to map indexes between proxy 2 and proxy 4, a KModelIndexProxyMapper can be created
  * to facilitate mapping of indexes between them.
  *
  * @code
  *   m_indexMapper = new KModelIndexProxyMapper(proxy2, proxy4, this);
  *
  *  ...
  *
  *   const QModelIndex proxy4Index = m_mapLeftToRight(proxy2->index(0, 0));
  *   Q_ASSERT(proxy4Index.model() == proxy4);
  * @endcode
  *
  * Note that the aim is to achieve black box connections so that there is no need for application code to
  * know the structure of proxy models in the path between left and right and attempt to manually map them.
  *
  * @verbatim
  *     Root model
  *         |
  *   ---------------
  *   |  Black Box  |
  *   ---------------
  *      |       |
  *   Proxy 2   Proxy 4
  * @endverbatim
  *
  * The isConnected property indicates whether there is a
  * path from the left side to the right side.
  *
  * @author Stephen Kelly <steveire@gmail.com>
  *
  */
 class KITEMMODELS_EXPORT KModelIndexProxyMapper : public QObject
 {
     Q_OBJECT
 
     /**
      * Indicates whether there is a chain that can be followed from leftModel to rightModel.
      *
      * This value can change if the sourceModel of an intermediate proxy is changed.
      */
     Q_PROPERTY(bool isConnected READ isConnected NOTIFY isConnectedChanged)
 public:
     /**
      * Constructor
      */
     KModelIndexProxyMapper(const QAbstractItemModel *leftModel, const QAbstractItemModel *rightModel, QObject *parent = nullptr);
 
     ~KModelIndexProxyMapper() override;
 
     /**
      * Maps the @p index from the left model to the right model.
      */
     QModelIndex mapLeftToRight(const QModelIndex &index) const;
 
     /**
      * Maps the @p index from the right model to the left model.
      */
     QModelIndex mapRightToLeft(const QModelIndex &index) const;
 
     /**
      * Maps the @p selection from the left model to the right model.
      */
     QItemSelection mapSelectionLeftToRight(const QItemSelection &selection) const;
 
     /**
      * Maps the @p selection from the right model to the left model.
      */
     QItemSelection mapSelectionRightToLeft(const QItemSelection &selection) const;
 
     bool isConnected() const;
 
 Q_SIGNALS:
     void isConnectedChanged();
 
 private:
     //@cond PRIVATE
     Q_DECLARE_PRIVATE(KModelIndexProxyMapper)
     std::unique_ptr<KModelIndexProxyMapperPrivate> const d_ptr;
     //@endcond
 };
 
 #endif