Item views: fix error when accessing attached view from non-delegates

Ensure that the view is set on the relevant attached objects before
QQmlComponent::completeCreate() is called, which would otherwise result
in a TypeError because the view would be set too late.

Fixes: QTBUG-104026
Task-number: QTBUG-98718
Change-Id: Ic65370bd4534e7452f2377ab4d60a74badf02079
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>
(cherry picked from commit dbd108a7997f129004bbed523db75d4aa9d0ab6c)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

4 files changed, 38 insertions, 2 deletions

diff --git a/src/quick/items/qquickgridview.cpp b/src/quick/items/qquickgridview.cpp
index 955048fa9f..47e27ea230 100644
--- a/src/quick/items/qquickgridview.cpp
+++ b/src/quick/items/qquickgridview.cpp
@@ -208,6 +208,8 @@ public:
     void updateHeader() override;
     void updateFooter() override;
 
+    void initializeComponentItem(QQuickItem *item) const override;
+
     void changedVisibleIndex(int newIndex) override;
     void initializeCurrentItem() override;
 
@@ -853,6 +855,14 @@ void QQuickGridViewPrivate::updateFooter()
         emit q->footerItemChanged();
 }
 
+void QQuickGridViewPrivate::initializeComponentItem(QQuickItem *item) const
+{
+    QQuickGridViewAttached *attached = static_cast<QQuickGridViewAttached *>(
+        qmlAttachedPropertiesObject<QQuickGridView>(item));
+    if (attached)
+        attached->setView(const_cast<QQuickGridView*>(q_func()));
+}
+
 void QQuickGridViewPrivate::updateHeader()
 {
     Q_Q(QQuickGridView);
diff --git a/src/quick/items/qquickitemview.cpp b/src/quick/items/qquickitemview.cpp
index 449e812060..8cd3f54f44 100644
--- a/src/quick/items/qquickitemview.cpp
+++ b/src/quick/items/qquickitemview.cpp
@@ -57,8 +57,6 @@ FxViewItem::FxViewItem(QQuickItem *i, QQuickItemView *v, bool own, QQuickItemVie
     , view(v)
     , attached(attached)
 {
-    if (attached) // can be null for default components (see createComponentItem)
-        attached->setView(view);
 }
 
 QQuickItemViewChangeSet::QQuickItemViewChangeSet()
@@ -2502,12 +2500,29 @@ QQuickItem *QQuickItemViewPrivate::createComponentItem(QQmlComponent *component,
             item->setZ(zValue);
         QQml_setParent_noEvent(item, q->contentItem());
         item->setParentItem(q->contentItem());
+
+        initializeComponentItem(item);
     }
     if (component)
         component->completeCreate();
     return item;
 }
 
+/*!
+    \internal
+
+    Allows derived classes to do any initialization required for \a item
+    before completeCreate() is called on it. For example, any attached
+    properties required by the item can be set.
+
+    This is similar to initItem(), but as that has logic specific to
+    delegate items, we use a separate function for non-delegates.
+*/
+void QQuickItemViewPrivate::initializeComponentItem(QQuickItem *item) const
+{
+    Q_UNUSED(item);
+}
+
 void QQuickItemViewPrivate::updateTrackedItem()
 {
     Q_Q(QQuickItemView);
diff --git a/src/quick/items/qquickitemview_p_p.h b/src/quick/items/qquickitemview_p_p.h
index 6d55b9b7dd..67bbeec8a1 100644
--- a/src/quick/items/qquickitemview_p_p.h
+++ b/src/quick/items/qquickitemview_p_p.h
@@ -178,6 +178,7 @@ public:
 
     QQuickItem *createHighlightItem() const;
     QQuickItem *createComponentItem(QQmlComponent *component, qreal zValue, bool createDefault = false) const;
+    virtual void initializeComponentItem(QQuickItem *) const;
 
     void updateCurrent(int modelIndex);
     void updateTrackedItem();
diff --git a/src/quick/items/qquicklistview.cpp b/src/quick/items/qquicklistview.cpp
index fa52f48825..14ff95163f 100644
--- a/src/quick/items/qquicklistview.cpp
+++ b/src/quick/items/qquicklistview.cpp
@@ -130,6 +130,8 @@ public:
     bool hasStickyHeader() const override;
     bool hasStickyFooter() const override;
 
+    void initializeComponentItem(QQuickItem *item) const override;
+
     void changedVisibleIndex(int newIndex) override;
     void initializeCurrentItem() override;
 
@@ -1573,6 +1575,14 @@ bool QQuickListViewPrivate::hasStickyFooter() const
     return footer && footerPositioning != QQuickListView::InlineFooter;
 }
 
+void QQuickListViewPrivate::initializeComponentItem(QQuickItem *item) const
+{
+    QQuickListViewAttached *attached = static_cast<QQuickListViewAttached *>(
+            qmlAttachedPropertiesObject<QQuickListView>(item));
+    if (attached) // can be null for default components (see createComponentItem)
+        attached->setView(const_cast<QQuickListView*>(q_func()));
+}
+
 void QQuickListViewPrivate::itemGeometryChanged(QQuickItem *item, QQuickGeometryChange change,
                                                 const QRectF &oldGeometry)
 {