QQuickTableView: Immediately delete delegates when possible

In the dtor we don't need to care about any side effects a direct
delete may have. Rather, any deleteLater() may not take effect
anymore as the event loop may be gone already.

Task-number: QTBUG-82000
Change-Id: I97935dc47fbbfd0c050e80c333c36a05f685c45d
Reviewed-by: Joni Poikelin <joni.poikelin@qt.io>
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

3 files changed, 30 insertions, 1 deletions

diff --git a/src/qmlmodels/qqmltableinstancemodel.cpp b/src/qmlmodels/qqmltableinstancemodel.cpp
index 9800eb8c72..e2cecfef79 100644
--- a/src/qmlmodels/qqmltableinstancemodel.cpp
+++ b/src/qmlmodels/qqmltableinstancemodel.cpp
@@ -240,6 +240,25 @@ QQmlInstanceModel::ReleaseFlags QQmlTableInstanceModel::release(QObject *object,
     return QQmlInstanceModel::Destroyed;
 }
 
+void QQmlTableInstanceModel::dispose(QObject *object)
+{
+    Q_ASSERT(object);
+    auto modelItem = qvariant_cast<QQmlDelegateModelItem *>(object->property(kModelItemTag));
+    Q_ASSERT(modelItem);
+
+    modelItem->releaseObject();
+
+    // The item is not referenced by anyone
+    Q_ASSERT(!modelItem->isObjectReferenced());
+    Q_ASSERT(!modelItem->isReferenced());
+
+    m_modelItems.remove(modelItem->index);
+
+    emit destroyingItem(object);
+    delete object;
+    delete modelItem;
+}
+
 void QQmlTableInstanceModel::cancel(int index)
 {
     auto modelItem = m_modelItems.value(index);
diff --git a/src/qmlmodels/qqmltableinstancemodel_p.h b/src/qmlmodels/qqmltableinstancemodel_p.h
index fd5968d872..4ea1d85d16 100644
--- a/src/qmlmodels/qqmltableinstancemodel_p.h
+++ b/src/qmlmodels/qqmltableinstancemodel_p.h
@@ -117,6 +117,7 @@ public:
     QObject *object(int index, QQmlIncubator::IncubationMode incubationMode = QQmlIncubator::AsynchronousIfNested) override;
     ReleaseFlags release(QObject *object) override { return release(object, NotReusable); }
     ReleaseFlags release(QObject *object, ReusableFlag reusable);
+    void dispose(QObject *object);
     void cancel(int) override;
 
     void insertIntoReusableItemsPool(QQmlDelegateModelItem *modelItem);
diff --git a/src/quick/items/qquicktableview.cpp b/src/quick/items/qquicktableview.cpp
index 4b34e3b2c1..4105996b31 100644
--- a/src/quick/items/qquicktableview.cpp
+++ b/src/quick/items/qquicktableview.cpp
@@ -441,7 +441,16 @@ QQuickTableViewPrivate::QQuickTableViewPrivate()
 
 QQuickTableViewPrivate::~QQuickTableViewPrivate()
 {
-    releaseLoadedItems(QQmlTableInstanceModel::NotReusable);
+    for (auto *fxTableItem : loadedItems) {
+        if (auto item = fxTableItem->item) {
+            if (fxTableItem->ownItem)
+                delete item;
+            else if (tableModel)
+                tableModel->dispose(item);
+        }
+        delete fxTableItem;
+    }
+
     if (tableModel)
         delete tableModel;
 }