dragdropimplementations.h

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/* ============================================================
 *
 * This file is a part of digiKam project
 * https://www.digikam.org
 *
 * Date        : 2011-01-02
 * Description : Sample implementations for drag and drop handling
 *
 * Copyright (C) 2009-2011 by Marcel Wiesweg <marcel dot wiesweg at gmx dot de>
 *
 * 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, 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.
 *
 * ============================================================ */
 
#ifndef DIGIKAM_DRAG_DROP_IMPLEMENTATIONS_H
#define DIGIKAM_DRAG_DROP_IMPLEMENTATIONS_H
 
// Qt includes
 
#include <QAbstractItemView>
 
// Local includes
 
#include "digikam_export.h"
#include "abstractitemdragdrophandler.h"
 
namespace Digikam
{
 
class DIGIKAM_EXPORT DragDropModelImplementation
{
public:
 
    DragDropModelImplementation();
    virtual ~DragDropModelImplementation();
 
    Qt::DropActions supportedDropActions()                          const;
    QStringList     mimeTypes()                                     const;
    bool            dropMimeData(const QMimeData*,
                                 Qt::DropAction,
                                 int,
                                 int,
                                 const QModelIndex&);
    QMimeData*      mimeData(const QModelIndexList& indexes)        const;
 
    virtual Qt::ItemFlags dragDropFlags(const QModelIndex& index)   const;
 
    Qt::ItemFlags dragDropFlagsV2(const QModelIndex& index)         const;
    virtual bool  isDragEnabled(const QModelIndex& index)           const;
    virtual bool  isDropEnabled(const QModelIndex& index)           const;
 
    void setDragDropHandler(AbstractItemDragDropHandler* handler);
    AbstractItemDragDropHandler* dragDropHandler()                  const;
 
#define DECLARE_MODEL_DRAG_DROP_METHODS                                            \
    virtual Qt::DropActions supportedDropActions()                  const override \
        { return DragDropModelImplementation::supportedDropActions();      }       \
    virtual QStringList mimeTypes()                                 const override \
        { return DragDropModelImplementation::mimeTypes();                 }       \
    virtual bool dropMimeData(const QMimeData* d, Qt::DropAction a,                \
                              int r, int c, const QModelIndex& p)         override \
        { return DragDropModelImplementation::dropMimeData(d, a, r, c, p); }       \
    virtual QMimeData* mimeData(const QModelIndexList& indexes)     const override \
        { return DragDropModelImplementation::mimeData(indexes);           }
 
protected:
 
    AbstractItemDragDropHandler* m_dragDropHandler;
 
private:
 
    Q_DISABLE_COPY(DragDropModelImplementation)
};
 
// --------------------------------------------------------------------------------------------
 
class DIGIKAM_EXPORT DragDropViewImplementation
{
public:
 
    DragDropViewImplementation()          = default;
    virtual ~DragDropViewImplementation() = default;
 
    virtual void cut();
    virtual void copy();
    virtual void paste();
 
protected:
 
    virtual QAbstractItemView* asView()                                        = 0;
 
    virtual AbstractItemDragDropHandler* dragDropHandler()               const = 0;
 
    virtual QModelIndex mapIndexForDragDrop(const QModelIndex& index)    const = 0;
 
    virtual QPixmap     pixmapForDrag(const QList<QModelIndex>& indexes) const = 0;
 
    void dragEnterEvent(QDragEnterEvent* event);
    void dragMoveEvent(QDragMoveEvent* e);
    void dropEvent(QDropEvent* e);
    void startDrag(Qt::DropActions supportedActions);
 
#define DECLARE_VIEW_DRAG_DROP_METHODS(ParentViewClass)                           \
    virtual QAbstractItemView* asView()                 override                  \
        { return this;                                             }              \
    void dragEnterEvent(QDragEnterEvent* e)             override                  \
        { DragDropViewImplementation::dragEnterEvent(e);           }              \
    void dragMoveEvent(QDragMoveEvent* e)               override                  \
        { ParentViewClass::dragMoveEvent(e);                                      \
          DragDropViewImplementation::dragMoveEvent(e);            }              \
    void dropEvent(QDropEvent* e)                       override                  \
        { ParentViewClass::dropEvent(e);                                          \
          DragDropViewImplementation::dropEvent(e);                }              \
    void startDrag(Qt::DropActions supportedActions)    override                  \
        { DragDropViewImplementation::startDrag(supportedActions); }
 
    void encodeIsCutSelection(QMimeData* mime, bool isCutSelection);
    bool decodeIsCutSelection(const QMimeData* mimeData);
 
private:
 
    Q_DISABLE_COPY(DragDropViewImplementation)
};
 
} // namespace Digikam
 
#endif // DIGIKAM_DRAG_DROP_IMPLEMENTATIONS_H