Provide the resetInternalData slot to cleanly reset data in proxy subclasses.

Direct subclasses of QAbstractItemModel are unnaffected as they can update
internal data in a slot connected to the sourceModel's modelReset signal or
layoutChanged signal.

Rehabilitated for 4.8. Should be reverted again in Qt 5.

Reviewed-by: gabi
Merge-request: 694

1 files changed, 22 insertions, 0 deletions

diff --git a/src/corelib/kernel/qabstractitemmodel.cpp b/src/corelib/kernel/qabstractitemmodel.cpp
index b7ac6aa..54cc301 100644
--- a/src/corelib/kernel/qabstractitemmodel.cpp
+++ b/src/corelib/kernel/qabstractitemmodel.cpp
@@ -1348,6 +1348,26 @@ void QAbstractItemModelPrivate::columnsRemoved(const QModelIndex &parent,
 */
 
 /*!
+    \since 4.8
+
+    This slot is called just after the internal data of a model is cleared
+    while it is being reset.
+
+    This slot is provided the convenience of subclasses of concrete proxy
+    models, such as subclasses of QSortFilterProxyModel which maintain extra
+    data.
+
+    \snippet doc/src/snippets/code/src_corelib_kernel_qabstractitemmodel.cpp 10
+
+    \sa modelAboutToBeReset(), modelReset()
+*/
+void QAbstractItemModel::resetInternalData()
+{
+
+}
+
+
+/*!
     Constructs an abstract item model with the given \a parent.
 */
 QAbstractItemModel::QAbstractItemModel(QObject *parent)
@@ -2888,6 +2908,7 @@ void QAbstractItemModel::reset()
     Q_D(QAbstractItemModel);
     emit modelAboutToBeReset();
     d->invalidatePersistentIndexes();
+    QMetaObject::invokeMethod(this, "resetInternalData");
     emit modelReset();
 }
 
@@ -2930,6 +2951,7 @@ void QAbstractItemModel::endResetModel()
 {
     Q_D(QAbstractItemModel);
     d->invalidatePersistentIndexes();
+    QMetaObject::invokeMethod(this, "resetInternalData");
     emit modelReset();
 }