Add dynamically-created Event Handlers to the relevant handlers vector

If any kind of Pointer Handler is created dynamically in JS by
calling Component.createObject(), QObject::setParent() is called
rather than passing the parent to the constructor, so
QQuickItemPrivate::data_append() did not take care of adding the
handler to QQuickItemPrivate's extra->pointerHandlers vector.
We need to use the auto-parent mechanism (just as we did with
handling dynamic creation of nested Windows in
8cb02e23abbefc9d020707fc1a2d8b6eb4e103b6). Added
QQuickItemPrivate::addPointerHandler() to put the prepend()
and implied setAcceptedMouseButtons() in one place.

Fixes: QTBUG-71427
Change-Id: I3be3dd033c1c89e6e5b5c3463e1a720bbe963281
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

1 files changed, 12 insertions, 5 deletions

diff --git a/src/quick/items/qquickitem.cpp b/src/quick/items/qquickitem.cpp
index 064406ee3c..015fe66202 100644
--- a/src/quick/items/qquickitem.cpp
+++ b/src/quick/items/qquickitem.cpp
@@ -3281,11 +3281,7 @@ void QQuickItemPrivate::data_append(QQmlListProperty<QObject> *prop, QObject *o)
             qWarning("Cannot add a QtQuick 1.0 item (%s) into a QtQuick 2.0 scene!", o->metaObject()->className());
         else if (QQuickPointerHandler *pointerHandler = qmlobject_cast<QQuickPointerHandler *>(o)) {
             Q_ASSERT(pointerHandler->parentItem() == that);
-            // Accept all buttons, and leave filtering to pointerEvent() and/or user JS,
-            // because there can be multiple handlers...
-            that->setAcceptedMouseButtons(Qt::AllButtons);
-            QQuickItemPrivate *p = QQuickItemPrivate::get(that);
-            p->extra.value().pointerHandlers.prepend(pointerHandler);
+            QQuickItemPrivate::get(that)->addPointerHandler(pointerHandler);
         } else {
             QQuickWindow *thisWindow = qmlobject_cast<QQuickWindow *>(o);
             QQuickItem *item = that;
@@ -8207,6 +8203,17 @@ bool QQuickItemPrivate::hasHoverHandlers() const
     return false;
 }
 
+void QQuickItemPrivate::addPointerHandler(QQuickPointerHandler *h)
+{
+    Q_Q(QQuickItem);
+    // Accept all buttons, and leave filtering to pointerEvent() and/or user JS,
+    // because there can be multiple handlers...
+    q->setAcceptedMouseButtons(Qt::AllButtons);
+    auto &handlers = extra.value().pointerHandlers;
+    if (!handlers.contains(h))
+        handlers.prepend(h);
+}
+
 #if QT_CONFIG(quick_shadereffect)
 QQuickItemLayer::QQuickItemLayer(QQuickItem *item)
     : m_item(item)