qwindowsdrag.h

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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#ifndef QWINDOWSDRAG_H
#define QWINDOWSDRAG_H
 
#include "qwindowsinternalmimedata.h"
 
#include <qpa/qplatformdrag.h>
#include <QtGui/qpixmap.h>
#include <QtGui/qdrag.h>
#include <QtCore/private/qcomobject_p.h>
 
struct IDropTargetHelper;
 
QT_BEGIN_NAMESPACE
 
class QPlatformScreen;
 
class QWindowsDropMimeData : public QWindowsInternalMimeData {
public:
    QWindowsDropMimeData() = default;
    IDataObject *retrieveDataObject() const override;
};
 
class QWindowsOleDropTarget : public QComObject<IDropTarget>
{
public:
    explicit QWindowsOleDropTarget(QWindow *w);
    ~QWindowsOleDropTarget() override;
 
    // IDropTarget methods
    STDMETHOD(DragEnter)
    (LPDATAOBJECT pDataObj, DWORD grfKeyState, POINTL pt, LPDWORD pdwEffect) noexcept override;
    STDMETHOD(DragOver)(DWORD grfKeyState, POINTL pt, LPDWORD pdwEffect) noexcept override;
    STDMETHOD(DragLeave)() noexcept override;
    STDMETHOD(Drop)
    (LPDATAOBJECT pDataObj, DWORD grfKeyState, POINTL pt, LPDWORD pdwEffect) noexcept override;
 
private:
    void handleDrag(QWindow *window, DWORD grfKeyState, const QPoint &, LPDWORD pdwEffect);
 
    QWindow *const m_window;
    QRect m_answerRect;
    QPoint m_lastPoint;
    DWORD m_chosenEffect = 0;
    DWORD m_lastKeyState = 0;
};
 
class QWindowsDrag : public QPlatformDrag
{
public:
    QWindowsDrag();
    virtual ~QWindowsDrag();
 
    Qt::DropAction drag(QDrag *drag) override;
 
    static QWindowsDrag *instance();
    void cancelDrag() override { QWindowsDrag::m_canceled = true; }
    static bool isCanceled() { return QWindowsDrag::m_canceled; }
 
    IDataObject *dropDataObject() const             { return m_dropDataObject; }
    void setDropDataObject(IDataObject *dataObject) { m_dropDataObject = dataObject; }
    void releaseDropDataObject();
    QMimeData *dropData();
 
    IDropTargetHelper* dropHelper();
 
private:
    static bool m_canceled;
 
    QWindowsDropMimeData m_dropData;
    IDataObject *m_dropDataObject = nullptr;
 
    IDropTargetHelper* m_cachedDropTargetHelper = nullptr;
};
 
QT_END_NAMESPACE
 
#endif // QWINDOWSDRAG_H