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diff --git a/vcl/inc/qt5/Qt5Transferable.hxx b/vcl/inc/qt5/Qt5Transferable.hxx
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+++ b/vcl/inc/qt5/Qt5Transferable.hxx
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+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ */
+
+#pragma once
+
+#include <cppuhelper/compbase.hxx>
+#include <com/sun/star/datatransfer/XTransferable.hpp>
+
+#include <QtCore/QMimeData>
+#include <QtCore/QStringList>
+#include <QtGui/QClipboard>
+
+/**
+ * Qt5Transferable classes are used to read QMimeData via the XTransferable
+ * interface. All the functionality is already implemented in the Qt5Transferable.
+ *
+ * The specialisations map to the two users, which provide QMimeData: the Clipboard
+ * and the Drag'n'Drop functionality.
+ *
+ * LO itself seem to just accept "text/plain;charset=utf-16", so it relies on the
+ * backend to convert to this charset, but still offers "text/plain" itself.
+ *
+ * It's the "mirror" interface of the Qt5MimeData, which is defined below.
+ **/
+class Qt5Transferable : public cppu::WeakImplHelper<css::datatransfer::XTransferable>
+{
+    Qt5Transferable(const Qt5Transferable&) = delete;
+
+    const QMimeData* m_pMimeData;
+    osl::Mutex m_aMutex;
+    bool m_bConvertFromLocale;
+    css::uno::Sequence<css::datatransfer::DataFlavor> m_aMimeTypeSeq;
+
+public:
+    Qt5Transferable(const QMimeData* pMimeData);
+    const QMimeData* mimeData() const { return m_pMimeData; }
+
+    css::uno::Sequence<css::datatransfer::DataFlavor> SAL_CALL getTransferDataFlavors() override;
+    sal_Bool SAL_CALL isDataFlavorSupported(const css::datatransfer::DataFlavor& rFlavor) override;
+    css::uno::Any SAL_CALL getTransferData(const css::datatransfer::DataFlavor& rFlavor) override;
+};
+
+/**
+ * The QClipboard's QMimeData is volatile. As written in the QClipboard::mimeData
+ * documentation, "the pointer returned might become invalidated when the contents
+ * of the clipboard changes". Therefore it can just be accessed reliably inside
+ * the QClipboard's object thread, which is the QApplication's thread, so all of
+ * the access has to go through RunInMainThread().
+ *
+ * If we detect a QMimeData change, we simply drop reporting any content. In theory
+ * we can recover in the case where there hadn't been any calls of the XTransferable
+ * interface, but currently we don't. But we ensure to never report mixed content,
+ * so we'll just cease operation on QMimeData change.
+ **/
+class Qt5ClipboardTransferable final : public Qt5Transferable
+{
+    // to detect in-flight QMimeData changes
+    const QClipboard::Mode m_aMode;
+
+    bool hasInFlightChanged() const;
+
+public:
+    explicit Qt5ClipboardTransferable(const QClipboard::Mode aMode, const QMimeData* pMimeData);
+
+    // these are the same then Qt5Transferable, except they go through RunInMainThread
+    css::uno::Sequence<css::datatransfer::DataFlavor> SAL_CALL getTransferDataFlavors() override;
+    sal_Bool SAL_CALL isDataFlavorSupported(const css::datatransfer::DataFlavor& rFlavor) override;
+    css::uno::Any SAL_CALL getTransferData(const css::datatransfer::DataFlavor& rFlavor) override;
+};
+
+/**
+ * Convenience typedef for better code readability
+ *
+ * This just uses the QMimeData provided by the QWidgets D'n'D events.
+ **/
+typedef Qt5Transferable Qt5DnDTransferable;
+
+/**
+ * A lazy loading QMimeData for XTransferable reads
+ *
+ * This is an interface class to make a XTransferable read accessible as a
+ * QMimeData. The mime data is just stored inside the XTransferable, never
+ * in the QMimeData itself! It's objects are just used for QClipboard to read
+ * the XTransferable data.
+ *
+ * Like XTransferable itself, this class should be considered an immutable
+ * container for mime data. There is no need to ever set any of its data.
+ *
+ * LO will offer at least UTF-16, if there is a viable text representation.
+ * If LO misses to offer a UTF-8 or a locale encoded string, these objects
+ * will offer them themselves and convert from UTF-16 on demand.
+ *
+ * It's the "mirror" interface of the Qt5Transferable.
+ **/
+class Qt5MimeData final : public QMimeData
+{
+    friend class Qt5ClipboardTransferable;
+
+    const css::uno::Reference<css::datatransfer::XTransferable> m_aContents;
+    mutable bool m_bHaveNoCharset; // = uses the locale charset
+    mutable bool m_bHaveUTF8;
+    mutable QStringList m_aMimeTypeList;
+
+    QVariant retrieveData(const QString& mimeType, QVariant::Type type) const override;
+
+public:
+    explicit Qt5MimeData(const css::uno::Reference<css::datatransfer::XTransferable>& aContents);
+
+    bool hasFormat(const QString& mimeType) const override;
+    QStringList formats() const override;
+
+    bool deepCopy(QMimeData** const) const;
+
+    css::datatransfer::XTransferable* xTransferable() const { return m_aContents.get(); }
+};
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */