5 files changed, 44 insertions, 3 deletions

diff --git a/src/quick/handlers/qquickpointerhandler.cpp b/src/quick/handlers/qquickpointerhandler.cpp
index 11c29ee812..254f91cfe1 100644
--- a/src/quick/handlers/qquickpointerhandler.cpp
+++ b/src/quick/handlers/qquickpointerhandler.cpp
@@ -302,7 +302,8 @@ void QQuickPointerHandler::onGrabChanged(QQuickPointerHandler *grabber, QPointin
 */
 void QQuickPointerHandler::setPassiveGrab(QPointerEvent *event, const QEventPoint &point, bool grab)
 {
-    qCDebug(lcPointerHandlerGrab) << point << grab;
+    qCDebug(lcPointerHandlerGrab) << this << point << grab << "via"
+                                  << QQuickDeliveryAgentPrivate::currentOrItemDeliveryAgent(parentItem());
     if (grab) {
         event->addPassiveGrabber(point, this);
     } else {
diff --git a/src/quick/items/qquickitem.cpp b/src/quick/items/qquickitem.cpp
index 464076cbf8..05e50d8e75 100644
--- a/src/quick/items/qquickitem.cpp
+++ b/src/quick/items/qquickitem.cpp
@@ -8178,6 +8178,12 @@ QPointF QQuickItem::mapFromScene(const QPointF &point) const
     treated only as a hint. So, the resulting window position may differ from
     what is expected.
 
+    \note If this item is in a subscene, e.g. mapped onto a 3D
+    \l [QtQuick3D QML] {Model}{Model} object, the UV mapping is incorporated
+    into this transformation, so that it really goes from screen coordinates to
+    this item's coordinates, as long as \a point is actually within this item's bounds.
+    The other mapping functions do not yet work that way.
+
     \since 5.7
 
     \sa {Concepts - Visual Coordinates in Qt Quick}
@@ -8185,7 +8191,12 @@ QPointF QQuickItem::mapFromScene(const QPointF &point) const
 QPointF QQuickItem::mapFromGlobal(const QPointF &point) const
 {
     Q_D(const QQuickItem);
-    return mapFromScene(d->globalToWindowTransform().map(point));
+    QPointF scenePoint = d->globalToWindowTransform().map(point);
+    if (auto da = QQuickDeliveryAgentPrivate::currentOrItemDeliveryAgent(this)) {
+        if (auto sceneTransform = da->sceneTransform())
+            scenePoint = sceneTransform->map(scenePoint);
+    }
+    return mapFromScene(scenePoint);
 }
 
 /*!
diff --git a/src/quick/util/qquickdeliveryagent.cpp b/src/quick/util/qquickdeliveryagent.cpp
index a38ac410d4..3b045ed8e4 100644
--- a/src/quick/util/qquickdeliveryagent.cpp
+++ b/src/quick/util/qquickdeliveryagent.cpp
@@ -626,6 +626,21 @@ void QQuickDeliveryAgentPrivate::updateFocusItemTransform()
 }
 
 /*! \internal
+    If called during event delivery, returns the agent that is delivering the
+    event, without checking whether \a item is reachable from there.
+    Otherwise returns QQuickItemPrivate::deliveryAgent() (the delivery agent for
+    the narrowest subscene containing \a item), or \c null if \a item is \c null.
+*/
+QQuickDeliveryAgent *QQuickDeliveryAgentPrivate::currentOrItemDeliveryAgent(const QQuickItem *item)
+{
+    if (currentEventDeliveryAgent)
+        return currentEventDeliveryAgent;
+    if (item)
+        return QQuickItemPrivate::get(const_cast<QQuickItem *>(item))->deliveryAgent();
+    return nullptr;
+}
+
+/*! \internal
     QQuickDeliveryAgent delivers events to a tree of Qt Quick Items, beginning
     with the given root item, which is usually QQuickWindow::rootItem() but
     may alternatively be embedded into a Qt Quick 3D scene or something else.
@@ -650,8 +665,20 @@ QQuickItem *QQuickDeliveryAgent::rootItem() const
 }
 
 /*! \internal
+    Returns the object that was set in setSceneTransform(): a functor that
+    transforms from scene coordinates in the parent scene to scene coordinates
+    within this DA's subscene, or \c null if none was set.
+*/
+QQuickDeliveryAgent::Transform *QQuickDeliveryAgent::sceneTransform() const
+{
+    Q_D(const QQuickDeliveryAgent);
+    return d->sceneTransform;
+}
+
+/*! \internal
     QQuickDeliveryAgent takes ownership of the given \a transform, which
-    encapsulates the ability to transform viewport coordinates to rootItem coordinates.
+    encapsulates the ability to transform parent scene coordinates to rootItem
+    (subscene) coordinates.
 */
 void QQuickDeliveryAgent::setSceneTransform(QQuickDeliveryAgent::Transform *transform)
 {
diff --git a/src/quick/util/qquickdeliveryagent_p.h b/src/quick/util/qquickdeliveryagent_p.h
index 9b73d9b9b9..df8c97b368 100644
--- a/src/quick/util/qquickdeliveryagent_p.h
+++ b/src/quick/util/qquickdeliveryagent_p.h
@@ -81,6 +81,7 @@ public:
 
     QQuickItem *rootItem() const;
 
+    Transform *sceneTransform() const;
     void setSceneTransform(Transform *transform);
     bool event(QEvent *ev) override;
 
diff --git a/src/quick/util/qquickdeliveryagent_p_p.h b/src/quick/util/qquickdeliveryagent_p_p.h
index ad1eece36e..f931cfd70b 100644
--- a/src/quick/util/qquickdeliveryagent_p_p.h
+++ b/src/quick/util/qquickdeliveryagent_p_p.h
@@ -121,6 +121,7 @@ public:
     static bool subsceneAgentsExist;
     // QQuickDeliveryAgent::event() sets this to the one that's currently (trying to) handle the event
     static QQuickDeliveryAgent *currentEventDeliveryAgent;
+    static QQuickDeliveryAgent *currentOrItemDeliveryAgent(const QQuickItem *item);
 
     Qt::FocusReason lastFocusReason = Qt::OtherFocusReason;
     int pointerEventRecursionGuard = 0;