QQuickPointerEvent and EventPoint: add localize(QQuickItem *)

During delivery we need to call
QQuickItem::mapFromScene(point->scenePos())
so let's do it as early as possible and store the result right in the
EventPoint.  That way the pos() property can be made available,
for the benefit of QML/JS signal handlers and also for C++ handlers.

Change-Id: I2706ffd6bc51a449eeba64f69c9ffdfb913c5ca6
Reviewed-by: Jan Arve Sæther <jan-arve.saether@theqtcompany.com>

3 files changed, 29 insertions, 3 deletions

diff --git a/src/quick/items/qquickevents.cpp b/src/quick/items/qquickevents.cpp
index 45e2fd3e73..c3156d0328 100644
--- a/src/quick/items/qquickevents.cpp
+++ b/src/quick/items/qquickevents.cpp
@@ -529,6 +529,14 @@ void QQuickEventPoint::reset(Qt::TouchPointState state, const QPointF &scenePos,
     m_velocity = velocity;
 }
 
+void QQuickEventPoint::localize(QQuickItem *target)
+{
+    if (target)
+        m_pos = target->mapFromScene(scenePos());
+    else
+        m_pos = QPointF();
+}
+
 QObject *QQuickEventPoint::grabber() const
 {
     return m_grabber.data();
@@ -638,6 +646,11 @@ QQuickPointerEvent *QQuickPointerMouseEvent::reset(QEvent *event)
     return this;
 }
 
+void QQuickPointerMouseEvent::localize(QQuickItem *target)
+{
+    m_mousePoint->localize(target);
+}
+
 QQuickPointerEvent *QQuickPointerTouchEvent::reset(QEvent *event)
 {
     auto ev = static_cast<QTouchEvent*>(event);
@@ -682,6 +695,12 @@ QQuickPointerEvent *QQuickPointerTouchEvent::reset(QEvent *event)
     return this;
 }
 
+void QQuickPointerTouchEvent::localize(QQuickItem *target)
+{
+    for (auto point : qAsConst(m_touchPoints))
+        point->localize(target);
+}
+
 QQuickEventPoint *QQuickPointerMouseEvent::point(int i) const {
     if (i == 0)
         return m_mousePoint;
diff --git a/src/quick/items/qquickevents_p_p.h b/src/quick/items/qquickevents_p_p.h
index 66393170ac..1c524e9e3b 100644
--- a/src/quick/items/qquickevents_p_p.h
+++ b/src/quick/items/qquickevents_p_p.h
@@ -250,6 +250,7 @@ private:
 class Q_QUICK_PRIVATE_EXPORT QQuickEventPoint : public QObject
 {
     Q_OBJECT
+    Q_PROPERTY(QPointF pos READ pos)
     Q_PROPERTY(QPointF scenePos READ scenePos)
     Q_PROPERTY(QPointF scenePressPos READ scenePressPos)
     Q_PROPERTY(QPointF sceneGrabPos READ sceneGrabPos)
@@ -273,10 +274,12 @@ public:
     QQuickEventPoint(QQuickPointerEvent *parent);
 
     void reset(Qt::TouchPointState state, const QPointF &scenePos, quint64 pointId, ulong timestamp, const QVector2D &velocity = QVector2D());
+    void localize(QQuickItem *target);
 
     void invalidate() { m_valid = false; }
 
     QQuickPointerEvent *pointerEvent() const;
+    QPointF pos() const { return m_pos; }
     QPointF scenePos() const { return m_scenePos; }
     QPointF scenePressPos() const { return m_scenePressPos; }
     QPointF sceneGrabPos() const { return m_sceneGrabPos; }
@@ -297,6 +300,7 @@ public:
     void setPointerHandlerGrabber(QQuickPointerHandler *grabber);
 
 private:
+    QPointF m_pos;
     QPointF m_scenePos;
     QPointF m_scenePressPos;
     QPointF m_sceneGrabPos;
@@ -365,6 +369,7 @@ public: // property accessors
 
 public: // helpers for C++ only (during event delivery)
     virtual QQuickPointerEvent *reset(QEvent *ev) = 0;
+    virtual void localize(QQuickItem *target) = 0;
 
     virtual bool isPressEvent() const = 0;
     virtual QQuickPointerMouseEvent *asPointerMouseEvent() { return nullptr; }
@@ -404,6 +409,7 @@ public:
         : QQuickPointerEvent(parent), m_mousePoint(new QQuickEventPoint(this)) { }
 
     QQuickPointerEvent *reset(QEvent *) override;
+    void localize(QQuickItem *target) override;
     bool isPressEvent() const override;
     QQuickPointerMouseEvent *asPointerMouseEvent() override { return this; }
     const QQuickPointerMouseEvent *asPointerMouseEvent() const override { return this; }
@@ -433,6 +439,7 @@ public:
     { }
 
     QQuickPointerEvent *reset(QEvent *) override;
+    void localize(QQuickItem *target) override;
     bool isPressEvent() const override;
     QQuickPointerTouchEvent *asPointerTouchEvent() override { return this; }
     const QQuickPointerTouchEvent *asPointerTouchEvent() const override { return this; }
diff --git a/src/quick/items/qquickwindow.cpp b/src/quick/items/qquickwindow.cpp
index 24943cb49d..20d4b3c5f6 100644
--- a/src/quick/items/qquickwindow.cpp
+++ b/src/quick/items/qquickwindow.cpp
@@ -2252,6 +2252,7 @@ bool QQuickWindowPrivate::deliverMatchingPointsToItem(QQuickItem *item, QQuickPo
 {
     Q_Q(QQuickWindow);
     QQuickItemPrivate *itemPrivate = QQuickItemPrivate::get(item);
+    pointerEvent->localize(item);
 
     // Let the Item's handlers (if any) have the event first.
     itemPrivate->handlePointerEvent(pointerEvent);
@@ -2264,9 +2265,8 @@ bool QQuickWindowPrivate::deliverMatchingPointsToItem(QQuickItem *item, QQuickPo
             auto point = event->point(0);
             if (point->isAccepted())
                 return false;
-            QPointF localPos = item->mapFromScene(point->scenePos());
-            Q_ASSERT(item->contains(localPos)); // transform is checked already
-            QMouseEvent *me = event->asMouseEvent(localPos);
+            Q_ASSERT(item->contains(point->pos())); // transform is checked already
+            QMouseEvent *me = event->asMouseEvent(point->pos());
             me->accept();
             q->sendEvent(item, me);
             if (me->isAccepted()) {