File indexing completed on 2024-04-21 14:56:37

 /*
     SPDX-FileCopyrightText: 2020 David Edmundson <davidedmundson@kde.org>
     SPDX-FileCopyrightText: 2021 Méven Car <meven.car@enioka.com>
 
     SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
 #include "waylandclipboard_p.h"
 
 #include <QBuffer>
 #include <QFile>
 #include <QGuiApplication>
 #include <QImageReader>
 #include <QImageWriter>
 #include <QMimeData>
 #include <QPointer>
 #include <QWindow>
 #include <QtWaylandClient/QWaylandClientExtension>
 #include <qpa/qplatformnativeinterface.h>
 #include <qtwaylandclientversion.h>
 
 #include <errno.h>
 #include <poll.h>
 #include <signal.h>
 #include <string.h>
 #include <unistd.h>
 
 #include "qwayland-wayland.h"
 #include "qwayland-wlr-data-control-unstable-v1.h"
 
 static inline QString applicationQtXImageLiteral()
 {
     return QStringLiteral("application/x-qt-image");
 }
 
 // copied from https://code.woboq.org/qt5/qtbase/src/gui/kernel/qinternalmimedata.cpp.html
 static QString utf8Text()
 {
     return QStringLiteral("text/plain;charset=utf-8");
 }
 
 static QStringList imageMimeFormats(const QList<QByteArray> &imageFormats)
 {
     QStringList formats;
     formats.reserve(imageFormats.size());
     for (const auto &format : imageFormats)
         formats.append(QLatin1String("image/") + QLatin1String(format.toLower()));
     // put png at the front because it is best
     int pngIndex = formats.indexOf(QLatin1String("image/png"));
     if (pngIndex != -1 && pngIndex != 0)
         formats.move(pngIndex, 0);
     return formats;
 }
 
 static inline QStringList imageReadMimeFormats()
 {
     return imageMimeFormats(QImageReader::supportedImageFormats());
 }
 
 static inline QStringList imageWriteMimeFormats()
 {
     return imageMimeFormats(QImageWriter::supportedImageFormats());
 }
 // end copied
 
 class DataControlDeviceManager : public QWaylandClientExtensionTemplate<DataControlDeviceManager>, public QtWayland::zwlr_data_control_manager_v1
 {
     Q_OBJECT
 public:
     DataControlDeviceManager()
         : QWaylandClientExtensionTemplate<DataControlDeviceManager>(2)
     {
     }
 
     void instantiate()
     {
 #if QTWAYLANDCLIENT_VERSION >= QT_VERSION_CHECK(6, 2, 0)
         initialize();
 #else
         // QWaylandClientExtensionTemplate invokes this with a QueuedConnection but we want shortcuts
         // to be have access to data_control immediately.
         QMetaObject::invokeMethod(this, "addRegistryListener");
 #endif
     }
 
     ~DataControlDeviceManager()
     {
         if (isInitialized()) {
             destroy();
         }
     }
 };
 
 class DataControlOffer : public QMimeData, public QtWayland::zwlr_data_control_offer_v1
 {
     Q_OBJECT
 public:
     DataControlOffer(struct ::zwlr_data_control_offer_v1 *id)
         : QtWayland::zwlr_data_control_offer_v1(id)
     {
     }
 
     ~DataControlOffer()
     {
         destroy();
     }
 
     QStringList formats() const override
     {
         return m_receivedFormats;
     }
 
     bool containsImageData() const
     {
         if (m_receivedFormats.contains(applicationQtXImageLiteral())) {
             return true;
         }
         const auto formats = imageReadMimeFormats();
         for (const auto &receivedFormat : m_receivedFormats) {
             if (formats.contains(receivedFormat)) {
                 return true;
             }
         }
         return false;
     }
 
     bool hasFormat(const QString &mimeType) const override
     {
         if (mimeType == QStringLiteral("text/plain") && m_receivedFormats.contains(utf8Text())) {
             return true;
         }
         if (m_receivedFormats.contains(mimeType)) {
             return true;
         }
 
         // If we have image data
         if (containsImageData()) {
             // is the requested output mimeType supported ?
             const QStringList imageFormats = imageWriteMimeFormats();
             for (const QString &imageFormat : imageFormats) {
                 if (imageFormat == mimeType) {
                     return true;
                 }
             }
             if (mimeType == applicationQtXImageLiteral()) {
                 return true;
             }
         }
 
         return false;
     }
 
 protected:
     void zwlr_data_control_offer_v1_offer(const QString &mime_type) override
     {
         m_receivedFormats << mime_type;
     }
 
 #if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
     QVariant retrieveData(const QString &mimeType, QMetaType type) const override;
 #else
     QVariant retrieveData(const QString &mimeType, QVariant::Type type) const override;
 #endif
 
 private:
     /** reads data from a file descriptor with a timeout of 1 second
      *  true if data is read successfully
      */
     static bool readData(int fd, QByteArray &data);
     QStringList m_receivedFormats;
 };
 
 #if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
 QVariant DataControlOffer::retrieveData(const QString &mimeType, QMetaType type) const
 #else
 QVariant DataControlOffer::retrieveData(const QString &mimeType, QVariant::Type type) const
 #endif
 {
     Q_UNUSED(type);
 
     QString mime;
     if (!m_receivedFormats.contains(mimeType)) {
         if (mimeType == QStringLiteral("text/plain") && m_receivedFormats.contains(utf8Text())) {
             mime = utf8Text();
         } else if (mimeType == applicationQtXImageLiteral()) {
             const auto writeFormats = imageWriteMimeFormats();
             for (const auto &receivedFormat : m_receivedFormats) {
                 if (writeFormats.contains(receivedFormat)) {
                     mime = receivedFormat;
                     break;
                 }
             }
             if (mime.isEmpty()) {
                 // default exchange format
                 mime = QStringLiteral("image/png");
             }
         }
 
         if (mime.isEmpty()) {
             return QVariant();
         }
     } else {
         mime = mimeType;
     }
 
     int pipeFds[2];
     if (pipe(pipeFds) != 0) {
         return QVariant();
     }
 
     auto t = const_cast<DataControlOffer *>(this);
     t->receive(mime, pipeFds[1]);
 
     close(pipeFds[1]);
 
     /*
      * Ideally we need to introduce a non-blocking QMimeData object
      * Or a non-blocking constructor to QMimeData with the mimetypes that are relevant
      *
      * However this isn't actually any worse than X.
      */
 
     QPlatformNativeInterface *native = qGuiApp->platformNativeInterface();
     auto display = static_cast<struct ::wl_display *>(native->nativeResourceForIntegration("wl_display"));
     wl_display_flush(display);
 
     QFile readPipe;
     if (readPipe.open(pipeFds[0], QIODevice::ReadOnly)) {
         QByteArray data;
         if (readData(pipeFds[0], data)) {
             close(pipeFds[0]);
 
             if (mimeType == applicationQtXImageLiteral()) {
                 QImage img = QImage::fromData(data, mime.mid(mime.indexOf(QLatin1Char('/')) + 1).toLatin1().toUpper().data());
                 if (!img.isNull()) {
                     return img;
                 }
             }
             return data;
         }
         close(pipeFds[0]);
     }
     return QVariant();
 }
 
 bool DataControlOffer::readData(int fd, QByteArray &data)
 {
     pollfd pfds[1];
     pfds[0].fd = fd;
     pfds[0].events = POLLIN;
 
     while (true) {
         const int ready = poll(pfds, 1, 1000);
         if (ready < 0) {
             if (errno != EINTR) {
                 qWarning("DataControlOffer: poll() failed: %s", strerror(errno));
                 return false;
             }
         } else if (ready == 0) {
             qWarning("DataControlOffer: timeout reading from pipe");
             return false;
         } else {
             char buf[4096];
             int n = read(fd, buf, sizeof buf);
 
             if (n < 0) {
                 qWarning("DataControlOffer: read() failed: %s", strerror(errno));
                 return false;
             } else if (n == 0) {
                 return true;
             } else if (n > 0) {
                 data.append(buf, n);
             }
         }
     }
 }
 
 class DataControlSource : public QObject, public QtWayland::zwlr_data_control_source_v1
 {
     Q_OBJECT
 public:
     DataControlSource(struct ::zwlr_data_control_source_v1 *id, QMimeData *mimeData);
     DataControlSource() = default;
     ~DataControlSource()
     {
         destroy();
     }
 
     QMimeData *mimeData()
     {
         return m_mimeData.get();
     }
     std::unique_ptr<QMimeData> releaseMimeData()
     {
         return std::move(m_mimeData);
     }
 
 Q_SIGNALS:
     void cancelled();
 
 protected:
     void zwlr_data_control_source_v1_send(const QString &mime_type, int32_t fd) override;
     void zwlr_data_control_source_v1_cancelled() override;
 
 private:
     std::unique_ptr<QMimeData> m_mimeData;
 };
 
 DataControlSource::DataControlSource(struct ::zwlr_data_control_source_v1 *id, QMimeData *mimeData)
     : QtWayland::zwlr_data_control_source_v1(id)
     , m_mimeData(mimeData)
 {
     const auto formats = mimeData->formats();
     for (const QString &format : formats) {
         offer(format);
     }
     if (mimeData->hasText()) {
         // ensure GTK applications get this mimetype to avoid them discarding the offer
         offer(QStringLiteral("text/plain;charset=utf-8"));
     }
 
     if (mimeData->hasImage()) {
         const QStringList imageFormats = imageWriteMimeFormats();
         for (const QString &imageFormat : imageFormats) {
             if (!formats.contains(imageFormat)) {
                 offer(imageFormat);
             }
         }
     }
 }
 
 void DataControlSource::zwlr_data_control_source_v1_send(const QString &mime_type, int32_t fd)
 {
     QString send_mime_type = mime_type;
     if (send_mime_type == QStringLiteral("text/plain;charset=utf-8")) {
         // if we get a request on the fallback mime, send the data from the original mime type
         send_mime_type = QStringLiteral("text/plain");
     }
 
     QByteArray ba;
     if (m_mimeData->hasImage()) {
         // adapted from QInternalMimeData::renderDataHelper
         if (mime_type == applicationQtXImageLiteral()) {
             QImage image = qvariant_cast<QImage>(m_mimeData->imageData());
             QBuffer buf(&ba);
             buf.open(QBuffer::WriteOnly);
             // would there not be PNG ??
             image.save(&buf, "PNG");
 
         } else if (mime_type.startsWith(QLatin1String("image/"))) {
             QImage image = qvariant_cast<QImage>(m_mimeData->imageData());
             QBuffer buf(&ba);
             buf.open(QBuffer::WriteOnly);
             image.save(&buf, mime_type.mid(mime_type.indexOf(QLatin1Char('/')) + 1).toLatin1().toUpper().data());
         }
         // end adapted
     } else {
         ba = m_mimeData->data(send_mime_type);
     }
 
     // Create a sigpipe handler that does nothing, or clients may be forced to terminate
     // if the pipe is closed in the other end.
     struct sigaction action, oldAction;
     action.sa_handler = SIG_IGN;
     sigemptyset(&action.sa_mask);
     action.sa_flags = 0;
     sigaction(SIGPIPE, &action, &oldAction);
     write(fd, ba.constData(), ba.size());
     sigaction(SIGPIPE, &oldAction, nullptr);
     close(fd);
 }
 
 void DataControlSource::zwlr_data_control_source_v1_cancelled()
 {
     Q_EMIT cancelled();
 }
 
 class DataControlDevice : public QObject, public QtWayland::zwlr_data_control_device_v1
 {
     Q_OBJECT
 public:
     DataControlDevice(struct ::zwlr_data_control_device_v1 *id)
         : QtWayland::zwlr_data_control_device_v1(id)
     {
     }
 
     ~DataControlDevice()
     {
         destroy();
     }
 
     void setSelection(std::unique_ptr<DataControlSource> selection);
     QMimeData *receivedSelection()
     {
         return m_receivedSelection.get();
     }
     QMimeData *selection()
     {
         return m_selection ? m_selection->mimeData() : nullptr;
     }
 
     void setPrimarySelection(std::unique_ptr<DataControlSource> selection);
     QMimeData *receivedPrimarySelection()
     {
         return m_receivedPrimarySelection.get();
     }
     QMimeData *primarySelection()
     {
         return m_primarySelection ? m_primarySelection->mimeData() : nullptr;
     }
 
 Q_SIGNALS:
     void receivedSelectionChanged();
     void selectionChanged();
 
     void receivedPrimarySelectionChanged();
     void primarySelectionChanged();
 
 protected:
     void zwlr_data_control_device_v1_data_offer(struct ::zwlr_data_control_offer_v1 *id) override
     {
         // this will become memory managed when we retrieve the selection event
         // a compositor calling data_offer without doing that would be a bug
         new DataControlOffer(id);
     }
 
     void zwlr_data_control_device_v1_selection(struct ::zwlr_data_control_offer_v1 *id) override
     {
         if (!id) {
             m_receivedSelection.reset();
         } else {
             auto derivated = QtWayland::zwlr_data_control_offer_v1::fromObject(id);
             auto offer = dynamic_cast<DataControlOffer *>(derivated); // dynamic because of the dual inheritance
             m_receivedSelection.reset(offer);
         }
         Q_EMIT receivedSelectionChanged();
     }
 
     void zwlr_data_control_device_v1_primary_selection(struct ::zwlr_data_control_offer_v1 *id) override
     {
         if (!id) {
             m_receivedPrimarySelection.reset();
         } else {
             auto derivated = QtWayland::zwlr_data_control_offer_v1::fromObject(id);
             auto offer = dynamic_cast<DataControlOffer *>(derivated); // dynamic because of the dual inheritance
             m_receivedPrimarySelection.reset(offer);
         }
         Q_EMIT receivedPrimarySelectionChanged();
     }
 
 private:
     std::unique_ptr<DataControlSource> m_selection; // selection set locally
     std::unique_ptr<DataControlOffer> m_receivedSelection; // latest selection set from externally to here
 
     std::unique_ptr<DataControlSource> m_primarySelection; // selection set locally
     std::unique_ptr<DataControlOffer> m_receivedPrimarySelection; // latest selection set from externally to here
     friend WaylandClipboard;
 };
 
 void DataControlDevice::setSelection(std::unique_ptr<DataControlSource> selection)
 {
     m_selection = std::move(selection);
     connect(m_selection.get(), &DataControlSource::cancelled, this, [this]() {
         m_selection.reset();
     });
     set_selection(m_selection->object());
     Q_EMIT selectionChanged();
 }
 
 void DataControlDevice::setPrimarySelection(std::unique_ptr<DataControlSource> selection)
 {
     m_primarySelection = std::move(selection);
     connect(m_primarySelection.get(), &DataControlSource::cancelled, this, [this]() {
         m_primarySelection.reset();
     });
 
     if (zwlr_data_control_device_v1_get_version(object()) >= ZWLR_DATA_CONTROL_DEVICE_V1_SET_PRIMARY_SELECTION_SINCE_VERSION) {
         set_primary_selection(m_primarySelection->object());
         Q_EMIT primarySelectionChanged();
     }
 }
 class Keyboard;
 // We are binding to Seat/Keyboard manually because we want to react to gaining focus but inside Qt the events are Qt and arrive to late
 class KeyboardFocusWatcher : public QWaylandClientExtensionTemplate<KeyboardFocusWatcher>, public QtWayland::wl_seat
 {
     Q_OBJECT
 public:
     KeyboardFocusWatcher()
         : QWaylandClientExtensionTemplate(5)
     {
 #if QTWAYLANDCLIENT_VERSION >= QT_VERSION_CHECK(6, 2, 0)
         initialize();
 #else
         QMetaObject::invokeMethod(this, "addRegistryListener");
 #endif
         auto native = qGuiApp->platformNativeInterface();
         auto display = static_cast<struct ::wl_display *>(native->nativeResourceForIntegration("wl_display"));
         // so we get capabilities
         wl_display_roundtrip(display);
     }
     ~KeyboardFocusWatcher() override
     {
         if (isActive()) {
             release();
         }
     }
     void seat_capabilities(uint32_t capabilities) override
     {
         const bool hasKeyboard = capabilities & capability_keyboard;
         if (hasKeyboard && !m_keyboard) {
             m_keyboard = std::make_unique<Keyboard>(get_keyboard(), *this);
         } else if (!hasKeyboard && m_keyboard) {
             m_keyboard.reset();
         }
     }
     bool hasFocus() const
     {
         return m_focus;
     }
 Q_SIGNALS:
     void keyboardEntered();
 
 private:
     friend Keyboard;
     bool m_focus = false;
     std::unique_ptr<Keyboard> m_keyboard;
 };
 
 class Keyboard : public QtWayland::wl_keyboard
 {
 public:
     Keyboard(::wl_keyboard *keyboard, KeyboardFocusWatcher &seat)
         : wl_keyboard(keyboard)
         , m_seat(seat)
     {
     }
     ~Keyboard()
     {
         release();
     }
 
 private:
     void keyboard_enter([[maybe_unused]] uint32_t serial, [[maybe_unused]] wl_surface *surface, [[maybe_unused]] wl_array *keys) override
     {
         m_seat.m_focus = true;
         Q_EMIT m_seat.keyboardEntered();
     }
     void keyboard_leave([[maybe_unused]] uint32_t serial, [[maybe_unused]] wl_surface *surface) override
     {
         m_seat.m_focus = false;
     }
     KeyboardFocusWatcher &m_seat;
 };
 
 WaylandClipboard::WaylandClipboard(QObject *parent)
     : KSystemClipboard(parent)
     , m_keyboardFocusWatcher(new KeyboardFocusWatcher)
     , m_manager(new DataControlDeviceManager)
 {
     connect(m_manager.get(), &DataControlDeviceManager::activeChanged, this, [this]() {
         if (m_manager->isActive()) {
             QPlatformNativeInterface *native = qApp->platformNativeInterface();
             if (!native) {
                 return;
             }
             auto seat = static_cast<struct ::wl_seat *>(native->nativeResourceForIntegration("wl_seat"));
             if (!seat) {
                 return;
             }
             m_device.reset(new DataControlDevice(m_manager->get_data_device(seat)));
 
             connect(m_device.get(), &DataControlDevice::receivedSelectionChanged, this, [this]() {
                 // When our source is still valid, so the offer is for setting it or we emit changed when it is cancelled
                 if (!m_device->selection()) {
                     Q_EMIT changed(QClipboard::Clipboard);
                 }
             });
             connect(m_device.get(), &DataControlDevice::selectionChanged, this, [this]() {
                 Q_EMIT changed(QClipboard::Clipboard);
             });
 
             connect(m_device.get(), &DataControlDevice::receivedPrimarySelectionChanged, this, [this]() {
                 // When our source is still valid, so the offer is for setting it or we emit changed when it is cancelled
                 if (!m_device->primarySelection()) {
                     Q_EMIT changed(QClipboard::Selection);
                 }
             });
             connect(m_device.get(), &DataControlDevice::primarySelectionChanged, this, [this]() {
                 Q_EMIT changed(QClipboard::Selection);
             });
 
         } else {
             m_device.reset();
         }
     });
 
     m_manager->instantiate();
 }
 
 WaylandClipboard::~WaylandClipboard() = default;
 
 bool WaylandClipboard::isValid()
 {
     return m_manager && m_manager->isInitialized();
 }
 
 void WaylandClipboard::setMimeData(QMimeData *mime, QClipboard::Mode mode)
 {
     if (!m_device) {
         return;
     }
 
     // roundtrip to have accurate focus state when losing focus but setting mime data before processing wayland events.
     auto native = qGuiApp->platformNativeInterface();
     auto display = static_cast<struct ::wl_display *>(native->nativeResourceForIntegration("wl_display"));
     wl_display_roundtrip(display);
 
     // If the application is focused, use the normal mechanism so a future paste will not deadlock itselfs
     if (m_keyboardFocusWatcher->hasFocus()) {
         QGuiApplication::clipboard()->setMimeData(mime, mode);
         return;
     }
     // If not, set the clipboard once the app receives focus to avoid the deadlock
     connect(m_keyboardFocusWatcher.get(), &KeyboardFocusWatcher::keyboardEntered, this, &WaylandClipboard::gainedFocus, Qt::UniqueConnection);
     auto source = std::make_unique<DataControlSource>(m_manager->create_data_source(), mime);
     if (mode == QClipboard::Clipboard) {
         m_device->setSelection(std::move(source));
     } else if (mode == QClipboard::Selection) {
         m_device->setPrimarySelection(std::move(source));
     }
 }
 
 void WaylandClipboard::gainedFocus()
 {
     disconnect(m_keyboardFocusWatcher.get(), &KeyboardFocusWatcher::keyboardEntered, this, nullptr);
     // QClipboard takes ownership of the QMimeData so we need to transfer and unset our selections
     if (auto &selection = m_device->m_selection) {
         std::unique_ptr<QMimeData> data = selection->releaseMimeData();
         WaylandClipboard::clear(QClipboard::Clipboard);
         QGuiApplication::clipboard()->setMimeData(data.release(), QClipboard::Clipboard);
     }
     if (auto &primarySelection = m_device->m_primarySelection) {
         std::unique_ptr<QMimeData> data = primarySelection->releaseMimeData();
         WaylandClipboard::clear(QClipboard::Selection);
         QGuiApplication::clipboard()->setMimeData(data.release(), QClipboard::Selection);
     }
 }
 
 void WaylandClipboard::clear(QClipboard::Mode mode)
 {
     if (!m_device) {
         return;
     }
     if (mode == QClipboard::Clipboard) {
         m_device->set_selection(nullptr);
         m_device->m_selection.reset();
     } else if (mode == QClipboard::Selection) {
         if (zwlr_data_control_device_v1_get_version(m_device->object()) >= ZWLR_DATA_CONTROL_DEVICE_V1_SET_PRIMARY_SELECTION_SINCE_VERSION) {
             m_device->set_primary_selection(nullptr);
             m_device->m_primarySelection.reset();
         }
     }
 }
 
 const QMimeData *WaylandClipboard::mimeData(QClipboard::Mode mode) const
 {
     if (!m_device) {
         return nullptr;
     }
 
     // return our locally set selection if it's not cancelled to avoid copying data to ourselves
     if (mode == QClipboard::Clipboard) {
         if (m_device->selection()) {
             return m_device->selection();
         }
         // This application owns the clipboard via the regular data_device, use it so we don't block ourselves
         if (QGuiApplication::clipboard()->ownsClipboard()) {
             return QGuiApplication::clipboard()->mimeData(mode);
         }
         return m_device->receivedSelection();
     } else if (mode == QClipboard::Selection) {
         if (m_device->primarySelection()) {
             return m_device->primarySelection();
         }
         // This application owns the primary selection via the regular primary_selection_device, use it so we don't block ourselves
         if (QGuiApplication::clipboard()->ownsSelection()) {
             return QGuiApplication::clipboard()->mimeData(mode);
         }
         return m_device->receivedPrimarySelection();
     }
     return nullptr;
 }
 
 #include "waylandclipboard.moc"