From e0e004c77140da5e454dadf4d6809c1603b5735d Mon Sep 17 00:00:00 2001
From: David Edmundson <davidedmundson@kde.org>
Date: Tue, 16 Feb 2021 09:51:47 +0000
Subject: [PATCH] Client: Implement DataDeviceV3

DataDeviceV2 fixes a leak of DataDevice resources.

DataDeviceV3 brings multiple improvements:

Action negotiation. The source announces which actions are supported,
the target then announces which subset of those action the target
supports and a preferred action. After negotiation both the source and
target are notified of which action is to be performed.

Drag sources are now notified when contents are dropped and when a
client has finished with the drag and drop operation.

A good test is the draggableicons example in QtBase.

Change-Id: I55e9759ca5a2e4218d02d863144a64ade53ef764
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>
(cherry picked from commit 283a2d61d03315495a52d82f356e7cb5292f4bb4)
---
 src/client/qwaylanddatadevice.cpp             | 84 ++++++++++++++-----
 src/client/qwaylanddatadevice_p.h             |  8 +-
 src/client/qwaylanddatadevicemanager.cpp      |  4 +-
 src/client/qwaylanddatadevicemanager_p.h      |  2 +-
 src/client/qwaylanddataoffer.cpp              | 25 ++++++
 src/client/qwaylanddataoffer_p.h              |  4 +
 src/client/qwaylanddatasource.cpp             | 27 +++++-
 src/client/qwaylanddatasource_p.h             | 10 ++-
 src/client/qwaylanddisplay.cpp                |  2 +-
 src/client/qwaylanddnd.cpp                    | 24 +++---
 src/client/qwaylanddnd_p.h                    |  7 +-
 .../client/datadevicev1/tst_datadevicev1.cpp  |  2 +-
 12 files changed, 153 insertions(+), 46 deletions(-)

--- a/src/client/qwaylanddatadevice.cpp
+++ b/src/client/qwaylanddatadevice.cpp
@@ -72,6 +72,8 @@ QWaylandDataDevice::QWaylandDataDevice(QWaylandDataDeviceManager *manager, QWayl
 
 QWaylandDataDevice::~QWaylandDataDevice()
 {
+    if (wl_data_device_get_version(object()) >= WL_DATA_DEVICE_RELEASE_SINCE_VERSION)
+        release();
 }
 
 QWaylandDataOffer *QWaylandDataDevice::selectionOffer() const
@@ -110,7 +112,7 @@ QWaylandDataOffer *QWaylandDataDevice::dragOffer() const
     return m_dragOffer.data();
 }
 
-bool QWaylandDataDevice::startDrag(QMimeData *mimeData, QWaylandWindow *icon)
+bool QWaylandDataDevice::startDrag(QMimeData *mimeData, Qt::DropActions supportedActions, QWaylandWindow *icon)
 {
     auto *seat = m_display->currentInputDevice();
     auto *origin = seat->pointerFocus();
@@ -129,8 +131,28 @@ bool QWaylandDataDevice::startDrag(QMimeData *mimeData, QWaylandWindow *icon)
         mimeData->setData("application/x-qt-avoid-empty-placeholder", QByteArray("1"));
 
     m_dragSource.reset(new QWaylandDataSource(m_display->dndSelectionHandler(), mimeData));
+
+    if (wl_data_device_get_version(object()) >= 3)
+        m_dragSource->set_actions(dropActionsToWl(supportedActions));
+
     connect(m_dragSource.data(), &QWaylandDataSource::cancelled, this, &QWaylandDataDevice::dragSourceCancelled);
-    connect(m_dragSource.data(), &QWaylandDataSource::targetChanged, this, &QWaylandDataDevice::dragSourceTargetChanged);
+    connect(m_dragSource.data(), &QWaylandDataSource::dndResponseUpdated, this, [this](bool accepted, Qt::DropAction action) {
+            auto drag = static_cast<QWaylandDrag *>(QGuiApplicationPrivate::platformIntegration()->drag());
+            // in old versions drop action is not set, so we guess
+            if (wl_data_source_get_version(m_dragSource->object()) < 3) {
+                drag->setResponse(accepted);
+            } else {
+                QPlatformDropQtResponse response(accepted, action);
+                drag->setResponse(response);
+            }
+    });
+    connect(m_dragSource.data(), &QWaylandDataSource::dndDropped, this, [](bool accepted, Qt::DropAction action) {
+        QPlatformDropQtResponse response(accepted, action);
+        static_cast<QWaylandDrag *>(QGuiApplicationPrivate::platformIntegration()->drag())->setDropResponse(response);
+    });
+    connect(m_dragSource.data(), &QWaylandDataSource::finished, this, []() {
+        static_cast<QWaylandDrag *>(QGuiApplicationPrivate::platformIntegration()->drag())->finishDrag();
+    });
 
     start_drag(m_dragSource->object(), origin->wlSurface(), icon->wlSurface(), m_display->currentInputDevice()->serial());
     return true;
@@ -159,7 +181,7 @@ void QWaylandDataDevice::data_device_drop()
         supportedActions = drag->supportedActions();
     } else if (m_dragOffer) {
         dragData = m_dragOffer->mimeData();
-        supportedActions = Qt::CopyAction | Qt::MoveAction | Qt::LinkAction;
+        supportedActions = m_dragOffer->supportedActions();
     } else {
         return;
     }
@@ -169,7 +191,11 @@ void QWaylandDataDevice::data_device_drop()
                                                                           QGuiApplication::keyboardModifiers());
 
     if (drag) {
-        static_cast<QWaylandDrag *>(QGuiApplicationPrivate::platformIntegration()->drag())->finishDrag(response);
+        auto drag =  static_cast<QWaylandDrag *>(QGuiApplicationPrivate::platformIntegration()->drag());
+        drag->setDropResponse(response);
+        drag->finishDrag();
+    } else if (m_dragOffer) {
+        m_dragOffer->finish();
     }
 }
 
@@ -193,7 +219,7 @@ void QWaylandDataDevice::data_device_enter(uint32_t serial, wl_surface *surface,
         supportedActions = drag->supportedActions();
     } else if (m_dragOffer) {
         dragData = m_dragOffer->mimeData();
-        supportedActions = Qt::CopyAction | Qt::MoveAction | Qt::LinkAction;
+        supportedActions = m_dragOffer->supportedActions();
     }
 
     const QPlatformDragQtResponse &response = QWindowSystemInterface::handleDrag(m_dragWindow, dragData, m_dragPoint, supportedActions,
@@ -204,11 +230,7 @@ void QWaylandDataDevice::data_device_enter(uint32_t serial, wl_surface *surface,
         static_cast<QWaylandDrag *>(QGuiApplicationPrivate::platformIntegration()->drag())->setResponse(response);
     }
 
-    if (response.isAccepted()) {
-        wl_data_offer_accept(m_dragOffer->object(), m_enterSerial, m_dragOffer->firstFormat().toUtf8().constData());
-    } else {
-        wl_data_offer_accept(m_dragOffer->object(), m_enterSerial, nullptr);
-    }
+    sendResponse(supportedActions, response);
 }
 
 void QWaylandDataDevice::data_device_leave()
@@ -242,10 +264,10 @@ void QWaylandDataDevice::data_device_motion(uint32_t time, wl_fixed_t x, wl_fixe
         supportedActions = drag->supportedActions();
     } else {
         dragData = m_dragOffer->mimeData();
-        supportedActions = Qt::CopyAction | Qt::MoveAction | Qt::LinkAction;
+        supportedActions = m_dragOffer->supportedActions();
     }
 
-    QPlatformDragQtResponse response = QWindowSystemInterface::handleDrag(m_dragWindow, dragData, m_dragPoint, supportedActions,
+    const QPlatformDragQtResponse response = QWindowSystemInterface::handleDrag(m_dragWindow, dragData, m_dragPoint, supportedActions,
                                                                           QGuiApplication::mouseButtons(),
                                                                           QGuiApplication::keyboardModifiers());
 
@@ -253,11 +275,7 @@ void QWaylandDataDevice::data_device_motion(uint32_t time, wl_fixed_t x, wl_fixe
         static_cast<QWaylandDrag *>(QGuiApplicationPrivate::platformIntegration()->drag())->setResponse(response);
     }
 
-    if (response.isAccepted()) {
-        wl_data_offer_accept(m_dragOffer->object(), m_enterSerial, m_dragOffer->firstFormat().toUtf8().constData());
-    } else {
-        wl_data_offer_accept(m_dragOffer->object(), m_enterSerial, nullptr);
-    }
+    sendResponse(supportedActions, response);
 }
 #endif // QT_CONFIG(draganddrop)
 
@@ -287,11 +305,6 @@ void QWaylandDataDevice::dragSourceCancelled()
     m_dragSource.reset();
 }
 
-void QWaylandDataDevice::dragSourceTargetChanged(const QString &mimeType)
-{
-    static_cast<QWaylandDrag *>(QGuiApplicationPrivate::platformIntegration()->drag())->updateTarget(mimeType);
-}
-
 QPoint QWaylandDataDevice::calculateDragPosition(int x, int y, QWindow *wnd) const
 {
     QPoint pnt(wl_fixed_to_int(x), wl_fixed_to_int(y));
@@ -304,6 +317,33 @@ QPoint QWaylandDataDevice::calculateDragPosition(int x, int y, QWindow *wnd) con
     }
     return pnt;
 }
+
+void QWaylandDataDevice::sendResponse(Qt::DropActions supportedActions, const QPlatformDragQtResponse &response)
+{
+    if (response.isAccepted()) {
+        if (wl_data_device_get_version(object()) >= 3)
+            m_dragOffer->set_actions(dropActionsToWl(supportedActions), dropActionsToWl(response.acceptedAction()));
+
+        m_dragOffer->accept(m_enterSerial, m_dragOffer->firstFormat());
+    } else {
+        m_dragOffer->accept(m_enterSerial, QString());
+    }
+}
+
+int QWaylandDataDevice::dropActionsToWl(Qt::DropActions actions)
+{
+
+    int wlActions = WL_DATA_DEVICE_MANAGER_DND_ACTION_NONE;
+    if (actions & Qt::CopyAction)
+        wlActions |= WL_DATA_DEVICE_MANAGER_DND_ACTION_COPY;
+    if (actions & (Qt::MoveAction | Qt::TargetMoveAction))
+        wlActions |= WL_DATA_DEVICE_MANAGER_DND_ACTION_MOVE;
+
+    // wayland does not support LinkAction at the time of writing
+    return wlActions;
+}
+
+
 #endif // QT_CONFIG(draganddrop)
 
 }
--- a/src/client/qwaylanddatadevice_p.h
+++ b/src/client/qwaylanddatadevice_p.h
@@ -64,6 +64,7 @@ QT_REQUIRE_CONFIG(wayland_datadevice);
 QT_BEGIN_NAMESPACE
 
 class QMimeData;
+class QPlatformDragQtResponse;
 class QWindow;
 
 namespace QtWaylandClient {
@@ -89,7 +90,7 @@ public:
 
 #if QT_CONFIG(draganddrop)
     QWaylandDataOffer *dragOffer() const;
-    bool startDrag(QMimeData *mimeData, QWaylandWindow *icon);
+    bool startDrag(QMimeData *mimeData, Qt::DropActions supportedActions, QWaylandWindow *icon);
     void cancelDrag();
 #endif
 
@@ -109,13 +110,16 @@ private Q_SLOTS:
 
 #if QT_CONFIG(draganddrop)
     void dragSourceCancelled();
-    void dragSourceTargetChanged(const QString &mimeType);
 #endif
 
 private:
 #if QT_CONFIG(draganddrop)
     QPoint calculateDragPosition(int x, int y, QWindow *wnd) const;
 #endif
+    void sendResponse(Qt::DropActions supportedActions, const QPlatformDragQtResponse &response);
+
+    static int dropActionsToWl(Qt::DropActions dropActions);
+
 
     QWaylandDisplay *m_display = nullptr;
     QWaylandInputDevice *m_inputDevice = nullptr;
--- a/src/client/qwaylanddatadevicemanager.cpp
+++ b/src/client/qwaylanddatadevicemanager.cpp
@@ -50,8 +50,8 @@ QT_BEGIN_NAMESPACE
 
 namespace QtWaylandClient {
 
-QWaylandDataDeviceManager::QWaylandDataDeviceManager(QWaylandDisplay *display, uint32_t id)
-    : wl_data_device_manager(display->wl_registry(), id, 1)
+QWaylandDataDeviceManager::QWaylandDataDeviceManager(QWaylandDisplay *display, int version, uint32_t id)
+    : wl_data_device_manager(display->wl_registry(), id, qMin(version, 3))
     , m_display(display)
 {
     // Create transfer devices for all input devices.
--- a/src/client/qwaylanddatadevicemanager_p.h
+++ b/src/client/qwaylanddatadevicemanager_p.h
@@ -68,7 +68,7 @@ class QWaylandInputDevice;
 class Q_WAYLAND_CLIENT_EXPORT QWaylandDataDeviceManager : public QtWayland::wl_data_device_manager
 {
 public:
-    QWaylandDataDeviceManager(QWaylandDisplay *display, uint32_t id);
+    QWaylandDataDeviceManager(QWaylandDisplay *display, int version, uint32_t id);
     ~QWaylandDataDeviceManager() override;
 
     QWaylandDataDevice *getDataDevice(QWaylandInputDevice *inputDevice);
--- a/src/client/qwaylanddataoffer.cpp
+++ b/src/client/qwaylanddataoffer.cpp
@@ -87,6 +87,15 @@ QMimeData *QWaylandDataOffer::mimeData()
     return m_mimeData.data();
 }
 
+Qt::DropActions QWaylandDataOffer::supportedActions() const
+{
+    if (wl_data_offer_get_version(const_cast<::wl_data_offer*>(object())) < 3) {
+        return Qt::MoveAction | Qt::CopyAction;
+    }
+
+    return m_supportedActions;
+}
+
 void QWaylandDataOffer::startReceiving(const QString &mimeType, int fd)
 {
     receive(mimeType, fd);
@@ -98,6 +107,22 @@ void QWaylandDataOffer::data_offer_offer(const QString &mime_type)
     m_mimeData->appendFormat(mime_type);
 }
 
+void QWaylandDataOffer::data_offer_action(uint32_t dnd_action)
+{
+    Q_UNUSED(dnd_action);
+    // This is the compositor telling the drag target what action it should perform
+    // It does not map nicely into Qt final drop semantics, other than pretending there is only one supported action?
+}
+
+void QWaylandDataOffer::data_offer_source_actions(uint32_t source_actions)
+{
+    m_supportedActions = Qt::DropActions();
+    if (source_actions & WL_DATA_DEVICE_MANAGER_DND_ACTION_MOVE)
+        m_supportedActions |= Qt::MoveAction;
+    if (source_actions & WL_DATA_DEVICE_MANAGER_DND_ACTION_COPY)
+        m_supportedActions |= Qt::CopyAction;
+}
+
 QWaylandMimeData::QWaylandMimeData(QWaylandAbstractDataOffer *dataOffer)
     : m_dataOffer(dataOffer)
 {
--- a/src/client/qwaylanddataoffer_p.h
+++ b/src/client/qwaylanddataoffer_p.h
@@ -82,6 +82,7 @@ public:
     explicit QWaylandDataOffer(QWaylandDisplay *display, struct ::wl_data_offer *offer);
     ~QWaylandDataOffer() override;
     QMimeData *mimeData() override;
+    Qt::DropActions supportedActions() const;
 
     QString firstFormat() const;
 
@@ -89,10 +90,13 @@ public:
 
 protected:
     void data_offer_offer(const QString &mime_type) override;
+    void data_offer_source_actions(uint32_t source_actions) override;
+    void data_offer_action(uint32_t dnd_action) override;
 
 private:
     QWaylandDisplay *m_display = nullptr;
     QScopedPointer<QWaylandMimeData> m_mimeData;
+    Qt::DropActions m_supportedActions;
 };
 
 
--- a/src/client/qwaylanddatasource.cpp
+++ b/src/client/qwaylanddatasource.cpp
@@ -105,7 +105,32 @@ void QWaylandDataSource::data_source_send(const QString &mime_type, int32_t fd)
 
 void QWaylandDataSource::data_source_target(const QString &mime_type)
 {
-    Q_EMIT targetChanged(mime_type);
+    m_accepted = !mime_type.isEmpty();
+    Q_EMIT dndResponseUpdated(m_accepted, m_dropAction);
+}
+
+void QWaylandDataSource::data_source_action(uint32_t action)
+{
+    Qt::DropAction qtAction = Qt::IgnoreAction;
+
+    if (action == WL_DATA_DEVICE_MANAGER_DND_ACTION_MOVE)
+        qtAction = Qt::MoveAction;
+    else if (action == WL_DATA_DEVICE_MANAGER_DND_ACTION_COPY)
+        qtAction = Qt::CopyAction;
+
+    m_dropAction = qtAction;
+    Q_EMIT dndResponseUpdated(m_accepted, m_dropAction);
+}
+
+void QWaylandDataSource::data_source_dnd_finished()
+{
+    Q_EMIT finished();
+}
+
+void QWaylandDataSource::data_source_dnd_drop_performed()
+{
+
+    Q_EMIT dndDropped(m_accepted, m_dropAction);
 }
 
 }
--- a/src/client/qwaylanddatasource_p.h
+++ b/src/client/qwaylanddatasource_p.h
@@ -75,16 +75,24 @@ public:
     ~QWaylandDataSource() override;
 
 Q_SIGNALS:
-    void targetChanged(const QString &mime_type);
     void cancelled();
+    void finished();
+
+    void dndResponseUpdated(bool accepted, Qt::DropAction action);
+    void dndDropped(bool accepted, Qt::DropAction action);
 
 protected:
     void data_source_cancelled() override;
     void data_source_send(const QString &mime_type, int32_t fd) override;
     void data_source_target(const QString &mime_type) override;
+    void data_source_dnd_drop_performed() override;
+    void data_source_dnd_finished() override;
+    void data_source_action(uint32_t action) override;
 
 private:
     QMimeData *m_mime_data = nullptr;
+    bool m_accepted = false;
+    Qt::DropAction m_dropAction = Qt::IgnoreAction;
 };
 
 }
--- a/src/client/qwaylanddisplay.cpp
+++ b/src/client/qwaylanddisplay.cpp
@@ -356,7 +356,7 @@ void QWaylandDisplay::registry_global(uint32_t id, const QString &interface, uin
         mInputDevices.append(inputDevice);
 #if QT_CONFIG(wayland_datadevice)
     } else if (interface == QStringLiteral("wl_data_device_manager")) {
-        mDndSelectionHandler.reset(new QWaylandDataDeviceManager(this, id));
+        mDndSelectionHandler.reset(new QWaylandDataDeviceManager(this, version, id));
 #endif
     } else if (interface == QStringLiteral("qt_surface_extension")) {
         mWindowExtension.reset(new QtWayland::qt_surface_extension(registry, id, 1));
--- a/src/client/qwaylanddnd.cpp
+++ b/src/client/qwaylanddnd.cpp
@@ -66,7 +66,7 @@ void QWaylandDrag::startDrag()
 {
     QBasicDrag::startDrag();
     QWaylandWindow *icon = static_cast<QWaylandWindow *>(shapedPixmapWindow()->handle());
-    if (m_display->currentInputDevice()->dataDevice()->startDrag(drag()->mimeData(), icon)) {
+    if (m_display->currentInputDevice()->dataDevice()->startDrag(drag()->mimeData(), drag()->supportedActions(), icon)) {
         icon->addAttachOffset(-drag()->hotSpot());
     } else {
         // Cancelling immediately does not work, since the event loop for QDrag::exec is started
@@ -103,31 +103,31 @@ void QWaylandDrag::endDrag()
     m_display->currentInputDevice()->handleEndDrag();
 }
 
-void QWaylandDrag::updateTarget(const QString &mimeType)
+void QWaylandDrag::setResponse(bool accepted)
 {
-    setCanDrop(!mimeType.isEmpty());
-
-    if (canDrop()) {
-        updateCursor(defaultAction(drag()->supportedActions(), m_display->currentInputDevice()->modifiers()));
-    } else {
-        updateCursor(Qt::IgnoreAction);
-    }
+    // This method is used for old DataDevices where the drag action is not communicated
+    Qt::DropAction action = defaultAction(drag()->supportedActions(), m_display->currentInputDevice()->modifiers());
+    setResponse(QPlatformDropQtResponse(accepted, action));
 }
 
-void QWaylandDrag::setResponse(const QPlatformDragQtResponse &response)
+void QWaylandDrag::setResponse(const QPlatformDropQtResponse &response)
 {
     setCanDrop(response.isAccepted());
 
     if (canDrop()) {
-        updateCursor(defaultAction(drag()->supportedActions(), m_display->currentInputDevice()->modifiers()));
+        updateCursor(response.acceptedAction());
     } else {
         updateCursor(Qt::IgnoreAction);
     }
 }
 
-void QWaylandDrag::finishDrag(const QPlatformDropQtResponse &response)
+void QWaylandDrag::setDropResponse(const QPlatformDropQtResponse &response)
 {
     setExecutedDropAction(response.acceptedAction());
+}
+
+void QWaylandDrag::finishDrag()
+{
     QKeyEvent event(QEvent::KeyPress, Qt::Key_Escape, Qt::NoModifier);
     eventFilter(shapedPixmapWindow(), &event);
 }
--- a/src/client/qwaylanddnd_p.h
+++ b/src/client/qwaylanddnd_p.h
@@ -71,9 +71,10 @@ public:
     QWaylandDrag(QWaylandDisplay *display);
     ~QWaylandDrag() override;
 
-    void updateTarget(const QString &mimeType);
-    void setResponse(const QPlatformDragQtResponse &response);
-    void finishDrag(const QPlatformDropQtResponse &response);
+    void setResponse(bool accepted);
+    void setResponse(const QPlatformDropQtResponse &response);
+    void setDropResponse(const QPlatformDropQtResponse &response);
+    void finishDrag();
 
 protected:
     void startDrag() override;
--- a/tests/auto/client/datadevicev1/tst_datadevicev1.cpp
+++ b/tests/auto/client/datadevicev1/tst_datadevicev1.cpp
@@ -35,7 +35,7 @@
 
 using namespace MockCompositor;
 
-constexpr int dataDeviceVersion = 1;
+constexpr int dataDeviceVersion = 3;
 
 class DataDeviceCompositor : public DefaultCompositor {
 public: