Move mouseGrabberItem into the QQuickPointerEvent

The idea is to manage the "grab" for mouse and touch points inside the
pointer event, instead of having awkward extra state in the window.

Change-Id: I4011c66c163159b0315bf8e284d8e1c7c460f108
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@qt.io>

4 files changed, 15 insertions, 14 deletions

diff --git a/src/quick/items/qquickevents.cpp b/src/quick/items/qquickevents.cpp
index 80a4e6bd9a..96eb59f518 100644
--- a/src/quick/items/qquickevents.cpp
+++ b/src/quick/items/qquickevents.cpp
@@ -574,7 +574,7 @@ QQuickEventPoint *QQuickPointerTouchEvent::point(int i) const {
 }
 
 QQuickEventPoint::QQuickEventPoint(QQuickPointerEvent *parent)
-  : QObject(parent), m_pointId(0), m_timestamp(0), m_pressTimestamp(0),
+  : QObject(parent), m_pointId(0), m_grabber(nullptr), m_timestamp(0), m_pressTimestamp(0),
     m_state(Qt::TouchPointReleased), m_valid(false), m_accept(false)
 {
     Q_UNUSED(m_reserved);
diff --git a/src/quick/items/qquickevents_p_p.h b/src/quick/items/qquickevents_p_p.h
index f2e06b69df..3cec7c782a 100644
--- a/src/quick/items/qquickevents_p_p.h
+++ b/src/quick/items/qquickevents_p_p.h
@@ -253,6 +253,7 @@ class Q_QUICK_PRIVATE_EXPORT QQuickEventPoint : public QObject
     Q_PROPERTY(quint64 pointId READ pointId)
     Q_PROPERTY(qreal timeHeld READ timeHeld)
     Q_PROPERTY(bool accepted READ isAccepted WRITE setAccepted)
+    Q_PROPERTY(QQuickItem *grabber READ grabber WRITE setGrabber)
 
 public:
     QQuickEventPoint(QQuickPointerEvent *parent);
@@ -280,10 +281,13 @@ public:
     qreal timeHeld() const { return (m_timestamp - m_pressTimestamp) / 1000.0; }
     bool isAccepted() const { return m_accept; }
     void setAccepted(bool accepted = true) { m_accept = accepted; }
+    QQuickItem *grabber() const { return m_grabber; }
+    void setGrabber(QQuickItem *grabber) { m_grabber = grabber; }
 
 private:
     QPointF m_scenePos;
     quint64 m_pointId;
+    QQuickItem *m_grabber;
     ulong m_timestamp;
     ulong m_pressTimestamp;
     Qt::TouchPointState m_state;
diff --git a/src/quick/items/qquickwindow.cpp b/src/quick/items/qquickwindow.cpp
index 7a524a1377..a8565be414 100644
--- a/src/quick/items/qquickwindow.cpp
+++ b/src/quick/items/qquickwindow.cpp
@@ -471,7 +471,6 @@ void QQuickWindowPrivate::renderSceneGraph(const QSize &size)
 QQuickWindowPrivate::QQuickWindowPrivate()
     : contentItem(0)
     , activeFocusItem(0)
-    , mouseGrabberItem(0)
 #ifndef QT_NO_CURSOR
     , cursorItem(0)
 #endif
@@ -751,7 +750,10 @@ void QQuickWindowPrivate::setMouseGrabber(QQuickItem *grabber)
 
     qCDebug(DBG_MOUSE_TARGET) << "grabber" << q->mouseGrabberItem() << "->" << grabber;
     QQuickItem *oldGrabber = q->mouseGrabberItem();
-    mouseGrabberItem = grabber;
+
+    QQuickPointerEvent *event = QQuickPointerDevice::genericMouseDevice()->pointerEvent();
+    Q_ASSERT(event->pointCount() == 1);
+    event->point(0)->setGrabber(grabber);
 
     if (grabber && touchMouseId != -1) {
         // update the touch item for mouse touch id to the new grabber
@@ -778,12 +780,10 @@ void QQuickWindowPrivate::grabTouchPoints(QQuickItem *grabber, const QVector<int
         if (oldGrabber)
             ungrab.insert(oldGrabber);
 
-        QQuickItem *originalMouseGrabberItem = mouseGrabberItem;
+        QQuickItem *mouseGrabberItem = q->mouseGrabberItem();
         if (touchMouseId == ids.at(i) && mouseGrabberItem && mouseGrabberItem != grabber) {
             qCDebug(DBG_MOUSE_TARGET) << "grabTouchPoints: grabber" << mouseGrabberItem << "-> null";
-            mouseGrabberItem = 0;
-            QEvent ev(QEvent::UngrabMouse);
-            q->sendEvent(originalMouseGrabberItem, &ev);
+            setMouseGrabber(nullptr);
         }
     }
     foreach (QQuickItem *oldGrabber, ungrab)
@@ -804,9 +804,7 @@ void QQuickWindowPrivate::removeGrabber(QQuickItem *grabber, bool mouse, bool to
     }
     if (Q_LIKELY(mouse) && q->mouseGrabberItem() == grabber) {
         qCDebug(DBG_MOUSE_TARGET) << "removeGrabber" << q->mouseGrabberItem() << "-> null";
-        mouseGrabberItem = 0;
-        QEvent ev(QEvent::UngrabMouse);
-        q->sendEvent(grabber, &ev);
+        setMouseGrabber(nullptr);
     }
 }
 
@@ -1481,9 +1479,9 @@ QObject *QQuickWindow::focusObject() const
 */
 QQuickItem *QQuickWindow::mouseGrabberItem() const
 {
-    Q_D(const QQuickWindow);
-
-    return d->mouseGrabberItem;
+    QQuickPointerEvent *event = QQuickPointerDevice::genericMouseDevice()->pointerEvent();
+    Q_ASSERT(event->pointCount());
+    return event->point(0)->grabber();
 }
 
 
diff --git a/src/quick/items/qquickwindow_p.h b/src/quick/items/qquickwindow_p.h
index 15ac701c54..0579295fca 100644
--- a/src/quick/items/qquickwindow_p.h
+++ b/src/quick/items/qquickwindow_p.h
@@ -125,7 +125,6 @@ public:
     void deliverKeyEvent(QKeyEvent *e);
 
     // Keeps track of the item currently receiving mouse events
-    QQuickItem *mouseGrabberItem;
 #ifndef QT_NO_CURSOR
     QQuickItem *cursorItem;
 #endif