QQmlDelegateModel: add incubationStatus(), and use it to determine 'requestedIndex'

We used to assign the currently incubating item to 'requestedIndex' based
on requested incubation mode alone. This is not sufficient, as the item
can also be loaded async when the mode is AsyncIfNested. To check if the
item is really loading async (and that we're not getting nullptr because
of some other failure), we need to ask the incubator.

Task-number: QTBUG-61537
Change-Id: Id1f458db4a7584a6b58d5bad0e7832ce4fc341dc
Reviewed-by: J-P Nurmi <jpnurmi@qt.io>

1 files changed, 20 insertions, 0 deletions

diff --git a/src/qml/types/qqmldelegatemodel.cpp b/src/qml/types/qqmldelegatemodel.cpp
index 4da7199d1e..9dd82494ca 100644
--- a/src/qml/types/qqmldelegatemodel.cpp
+++ b/src/qml/types/qqmldelegatemodel.cpp
@@ -1036,6 +1036,16 @@ QObject *QQmlDelegateModel::object(int index, QQmlIncubator::IncubationMode incu
     return d->object(d->m_compositorGroup, index, incubationMode);
 }
 
+QQmlIncubator::Status QQmlDelegateModel::incubationStatus(int index)
+{
+    Q_D(QQmlDelegateModel);
+    Compositor::iterator it = d->m_compositor.find(d->m_compositorGroup, index);
+    if (!it->inCache())
+        return QQmlIncubator::Null;
+
+    return d->m_cache.at(it.cacheIndex)->incubationTask->status();
+}
+
 QString QQmlDelegateModelPrivate::stringValue(Compositor::Group group, int index, const QString &name)
 {
     Compositor::iterator it = m_compositor.find(group, index);
@@ -3203,6 +3213,16 @@ void QQmlPartsModel::setWatchedRoles(const QList<QByteArray> &roles)
     m_watchedRoles = roles;
 }
 
+QQmlIncubator::Status QQmlPartsModel::incubationStatus(int index)
+{
+    QQmlDelegateModelPrivate *model = QQmlDelegateModelPrivate::get(m_model);
+    Compositor::iterator it = model->m_compositor.find(model->m_compositorGroup, index);
+    if (!it->inCache())
+        return QQmlIncubator::Null;
+
+    return model->m_cache.at(it.cacheIndex)->incubationTask->status();
+}
+
 int QQmlPartsModel::indexOf(QObject *item, QObject *) const
 {
     QHash<QObject *, QQuickPackage *>::const_iterator it = m_packaged.find(item);