vcl/inc/qt5/Qt5Transferable.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  */
  10
  11 #pragma once
  12
  13 #include <cppuhelper/compbase.hxx>
  14 #include <com/sun/star/datatransfer/XTransferable.hpp>
  15
  16 #include <QtCore/QMimeData>
  17 #include <QtCore/QStringList>
  18 #include <QtGui/QClipboard>
  19
  20 /**
  21  * Qt5Transferable classes are used to read QMimeData via the XTransferable
  22  * interface. All the functionality is already implemented in the Qt5Transferable.
  23  *
  24  * The specialisations map to the two users, which provide QMimeData: the Clipboard
  25  * and the Drag'n'Drop functionality.
  26  *
  27  * LO itself seem to just accept "text/plain;charset=utf-16", so it relies on the
  28  * backend to convert to this charset, but still offers "text/plain" itself.
  29  *
  30  * It's the "mirror" interface of the Qt5MimeData, which is defined below.
  31  **/
  32 class Qt5Transferable : public cppu::WeakImplHelper<css::datatransfer::XTransferable>
  33 {
  34     Qt5Transferable(const Qt5Transferable&) = delete;
  35
  36     const QMimeData* m_pMimeData;
  37     osl::Mutex m_aMutex;
  38     bool m_bConvertFromLocale;
  39     css::uno::Sequence<css::datatransfer::DataFlavor> m_aMimeTypeSeq;
  40
  41 public:
  42     Qt5Transferable(const QMimeData* pMimeData);
  43     const QMimeData* mimeData() const { return m_pMimeData; }
  44
  45     css::uno::Sequence<css::datatransfer::DataFlavor> SAL_CALL getTransferDataFlavors() override;
  46     sal_Bool SAL_CALL isDataFlavorSupported(const css::datatransfer::DataFlavor& rFlavor) override;
  47     css::uno::Any SAL_CALL getTransferData(const css::datatransfer::DataFlavor& rFlavor) override;
  48 };
  49
  50 /**
  51  * The QClipboard's QMimeData is volatile. As written in the QClipboard::mimeData
  52  * documentation, "the pointer returned might become invalidated when the contents
  53  * of the clipboard changes". Therefore it can just be accessed reliably inside
  54  * the QClipboard's object thread, which is the QApplication's thread, so all of
  55  * the access has to go through RunInMainThread().
  56  *
  57  * If we detect a QMimeData change, we simply drop reporting any content. In theory
  58  * we can recover in the case where there hadn't been any calls of the XTransferable
  59  * interface, but currently we don't. But we ensure to never report mixed content,
  60  * so we'll just cease operation on QMimeData change.
  61  **/
  62 class Qt5ClipboardTransferable final : public Qt5Transferable
  63 {
  64     // to detect in-flight QMimeData changes
  65     const QClipboard::Mode m_aMode;
  66
  67     bool hasInFlightChanged() const;
  68
  69 public:
  70     explicit Qt5ClipboardTransferable(const QClipboard::Mode aMode, const QMimeData* pMimeData);
  71
  72     // these are the same then Qt5Transferable, except they go through RunInMainThread
  73     css::uno::Sequence<css::datatransfer::DataFlavor> SAL_CALL getTransferDataFlavors() override;
  74     sal_Bool SAL_CALL isDataFlavorSupported(const css::datatransfer::DataFlavor& rFlavor) override;
  75     css::uno::Any SAL_CALL getTransferData(const css::datatransfer::DataFlavor& rFlavor) override;
  76 };
  77
  78 /**
  79  * Convenience typedef for better code readability
  80  *
  81  * This just uses the QMimeData provided by the QWidgets D'n'D events.
  82  **/
  83 typedef Qt5Transferable Qt5DnDTransferable;
  84
  85 /**
  86  * A lazy loading QMimeData for XTransferable reads
  87  *
  88  * This is an interface class to make a XTransferable read accessible as a
  89  * QMimeData. The mime data is just stored inside the XTransferable, never
  90  * in the QMimeData itself! It's objects are just used for QClipboard to read
  91  * the XTransferable data.
  92  *
  93  * Like XTransferable itself, this class should be considered an immutable
  94  * container for mime data. There is no need to ever set any of its data.
  95  *
  96  * LO will offer at least UTF-16, if there is a viable text representation.
  97  * If LO misses to offer a UTF-8 or a locale encoded string, these objects
  98  * will offer them themselves and convert from UTF-16 on demand.
  99  *
 100  * It's the "mirror" interface of the Qt5Transferable.
 101  **/
 102 class Qt5MimeData final : public QMimeData
 103 {
 104     friend class Qt5ClipboardTransferable;
 105
 106     const css::uno::Reference<css::datatransfer::XTransferable> m_aContents;
 107     mutable bool m_bHaveNoCharset; // = uses the locale charset
 108     mutable bool m_bHaveUTF8;
 109     mutable QStringList m_aMimeTypeList;
 110
 111     QVariant retrieveData(const QString& mimeType, QVariant::Type type) const override;
 112
 113 public:
 114     explicit Qt5MimeData(const css::uno::Reference<css::datatransfer::XTransferable>& aContents);
 115
 116     bool hasFormat(const QString& mimeType) const override;
 117     QStringList formats() const override;
 118
 119     bool deepCopy(QMimeData** const) const;
 120
 121     css::datatransfer::XTransferable* xTransferable() const { return m_aContents.get(); }
 122 };
 123
 124 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */