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

This was part of Qt 4.8, but Qt 5.0 was branched before that, so
the commit was lost.

Change-Id: I2a2ab3c75a0943ac734d588ebd74bc158dd6aaaf
Reviewed-by: Nils Jeisecke <jeisecke@saltation.de>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

2 files changed, 26 insertions, 0 deletions

diff --git a/src/corelib/itemmodels/qabstractitemmodel.cpp b/src/corelib/itemmodels/qabstractitemmodel.cpp
index 2a2d376a26..90e9886c90 100644
--- a/src/corelib/itemmodels/qabstractitemmodel.cpp
+++ b/src/corelib/itemmodels/qabstractitemmodel.cpp
@@ -866,6 +866,27 @@ 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 code/src_corelib_kernel_qabstractitemmodel.cpp 12
+
+    \note Due to a mistake, this slot is missing in Qt 5.0.
+
+    \sa modelAboutToBeReset(), modelReset()
+*/
+void QAbstractItemModel::resetInternalData()
+{
+
+}
+
+/*!
     \class QModelIndex
     \inmodule QtCore
 
@@ -3055,6 +3076,7 @@ void QAbstractItemModel::endResetModel()
 {
     Q_D(QAbstractItemModel);
     d->invalidatePersistentIndexes();
+    QMetaObject::invokeMethod(this, "resetInternalData");
     emit modelReset(QPrivateSignal());
 }
 
diff --git a/src/corelib/itemmodels/qabstractitemmodel.h b/src/corelib/itemmodels/qabstractitemmodel.h
index 8e4f12e9ea..6a57ccaca8 100644
--- a/src/corelib/itemmodels/qabstractitemmodel.h
+++ b/src/corelib/itemmodels/qabstractitemmodel.h
@@ -330,6 +330,10 @@ public Q_SLOTS:
     virtual bool submit();
     virtual void revert();
 
+protected Q_SLOTS:
+    // Qt 6: Make virtual
+    void resetInternalData();
+
 protected:
     QAbstractItemModel(QAbstractItemModelPrivate &dd, QObject *parent = 0);