QQuickItemView: Fix model creation

In setDelegate(), we want to create the model if it doesn't exist, not
if it's not ours. Otherwise we might overwrite a perfectly fine model
set by user code when creating a delegate.

Also warn when we cannot retain an explicitly set delegate because an
incompatible model was passed.

Pick-to: 6.9 6.8
Change-Id: I43635d4cc2fcd0f539e1cfdf742a7d941323c2fe
Reviewed-by: Shawn Rutledge <[email protected]>
Reviewed-by: Fabian Kosmale <[email protected]>

1 files changed, 11 insertions, 0 deletions

diff --git a/src/quick/items/qquickitemview_p_p.h b/src/quick/items/qquickitemview_p_p.h
index b5d70c6d6f..5317d2cf8f 100644
--- a/src/quick/items/qquickitemview_p_p.h
+++ b/src/quick/items/qquickitemview_p_p.h
@@ -229,6 +229,16 @@ public:
             releaseItem(item, reusableFlag);
     }
 
+    QQmlDelegateModel *createDelegateModel(QQuickItemView *q) {
+        Q_ASSERT(model.isNull());
+        QQmlDelegateModel *delegateModel = new QQmlDelegateModel(qmlContext(q), q);
+        model = delegateModel;
+        ownModel = true;
+        if (q->isComponentComplete())
+            delegateModel->componentComplete();
+        return delegateModel;
+    }
+
     void emitCountChanged();
 
     virtual QQuickItemViewAttached *getAttachedObject(const QObject *) const { return nullptr; }
@@ -310,6 +320,7 @@ public:
 #endif
     bool delegateValidated : 1;
     bool isClearing : 1;
+    bool explicitDelegate: 1;
 
 protected:
     virtual Qt::Orientation layoutOrientation() const = 0;