Move qqmlsortfilterproxymodel private class to a separate file

The components used by QQmlSortFilterProxyModel (such as
QQmlSorterCompositor) require access to the
QQmlSortFilterProxyModelPrivate members, which are not possible as
of now, and thus it would be better to keep it separate and,
include it wherever required.

Pick-to: 6.10
Change-Id: I4159a0ef988dc0a67dfb2ed8443137fa91e5a5d9
Reviewed-by: Mitch Curtis <[email protected]>

4 files changed, 259 insertions, 165 deletions

diff --git a/src/qmlmodels/CMakeLists.txt b/src/qmlmodels/CMakeLists.txt
index 29ab77c793..a06d3c9702 100644
--- a/src/qmlmodels/CMakeLists.txt
+++ b/src/qmlmodels/CMakeLists.txt
@@ -76,7 +76,7 @@ qt_internal_extend_target(QmlModels CONDITION QT_FEATURE_qml_delegate_model
 qt_internal_extend_target(QmlModels CONDITION QT_FEATURE_qml_sfpm_model AND QT_FEATURE_proxymodel
     SOURCES
         sfpm/qqmlsortfilterproxymodel_p.h sfpm/qqmlsortfilterproxymodel.cpp
-        sfpm/qsortfilterproxymodelhelper_p.h sfpm/qsortfilterproxymodelhelper.cpp
+        sfpm/qqmlsortfilterproxymodel_p_p.h sfpm/qsortfilterproxymodelhelper_p.h sfpm/qsortfilterproxymodelhelper.cpp
         # sfpm filter specific source files
         sfpm/filters/qqmlfilterbase_p.h sfpm/filters/qqmlfilterbase.cpp
         sfpm/filters/qqmlfiltercompositor_p.h sfpm/filters/qqmlfiltercompositor.cpp
diff --git a/src/qmlmodels/sfpm/qqmlsortfilterproxymodel.cpp b/src/qmlmodels/sfpm/qqmlsortfilterproxymodel.cpp
index 11cbfddb1c..adae312f8d 100644
--- a/src/qmlmodels/sfpm/qqmlsortfilterproxymodel.cpp
+++ b/src/qmlmodels/sfpm/qqmlsortfilterproxymodel.cpp
@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
 #include <QtCore/qitemselectionmodel.h>
+#include <QtQmlModels/private/qqmlsortfilterproxymodel_p_p.h>
 #include <QtQmlModels/private/qqmlsortfilterproxymodel_p.h>
 #include <QtQmlModels/private/qqmlfiltercompositor_p.h>
 #include <QtQmlModels/private/qqmlsortercompositor_p.h>
@@ -119,164 +120,6 @@ Q_LOGGING_CATEGORY (lcSortFilterProxyModel, "qt.qml.sortfilterproxymodel")
     order as specified in the list.
 */
 
-class QQmlSortFilterProxyModelPrivate : public QAbstractProxyModelPrivate, public QSortFilterProxyModelHelper
-{
-    Q_DECLARE_PUBLIC(QQmlSortFilterProxyModel)
-
-public:
-    void init();
-
-    bool containRoleForRecursiveFilter(const QList<int> &roles) const;
-    bool recursiveParentAcceptsRow(const QModelIndex &source_parent) const;
-    bool recursiveChildAcceptsRow(int source_row, const QModelIndex &source_parent) const;
-
-    QList<std::pair<int, QList<int>>> proxy_intervals_for_source_items_to_add(
-            const QList<int> &proxy_to_source, const QList<int> &source_items,
-            const QModelIndex &source_parent, QSortFilterProxyModelHelper::Direction direction) const override;
-    bool needsReorder(const QList<int> &source_rows, const QModelIndex &source_parent) const;
-    bool updatePrimaryColumn();
-    int findPrimarySortColumn() const;
-
-    inline QModelIndex create_index(int row, int column,
-                                    QHash<QtPrivate::QModelIndexWrapper, QSortFilterProxyModelHelper::Mapping *>::const_iterator it) const {
-        return q_func()->createIndex(row, column, *it);
-    }
-    void changePersistentIndexList(const QModelIndexList &from, const QModelIndexList &to) override {
-        Q_Q(QQmlSortFilterProxyModel);
-        q->changePersistentIndexList(from, to);
-    }
-
-    void beginInsertRows(const QModelIndex &parent, int first, int last) override {
-        Q_Q(QQmlSortFilterProxyModel);
-        q->beginInsertRows(parent, first, last);
-    }
-
-    void beginInsertColumns(const QModelIndex &parent, int first, int last) override {
-        Q_Q(QQmlSortFilterProxyModel);
-        q->beginInsertColumns(parent, first, last);
-    }
-
-    void endInsertRows() override {
-        Q_Q(QQmlSortFilterProxyModel);
-        q->endInsertRows();
-    }
-
-    void endInsertColumns() override {
-        Q_Q(QQmlSortFilterProxyModel);
-        q->endInsertColumns();
-    }
-
-    void beginRemoveRows(const QModelIndex &parent, int first, int last) override {
-        Q_Q(QQmlSortFilterProxyModel);
-        q->beginRemoveRows(parent, first, last);
-    }
-
-    void beginRemoveColumns(const QModelIndex &parent, int first, int last) override {
-        Q_Q(QQmlSortFilterProxyModel);
-        q->beginRemoveColumns(parent, first, last);
-    }
-
-    void endRemoveRows() override {
-        Q_Q(QQmlSortFilterProxyModel);
-        q->endRemoveRows();
-    }
-
-    void endRemoveColumns() override {
-        Q_Q(QQmlSortFilterProxyModel);
-        q->endRemoveColumns();
-    }
-
-    void beginResetModel() override {
-        Q_Q(QQmlSortFilterProxyModel);
-        q->beginResetModel();
-    }
-
-    void endResetModel() override {
-        Q_Q(QQmlSortFilterProxyModel);
-        q->endResetModel();
-    }
-
-    // Update the proxy model when there is any change in the source model
-    void _q_sourceDataChanged(const QModelIndex &source_top_left,
-                              const QModelIndex &source_bottom_right,
-                              const QList<int> &roles);
-    void _q_sourceHeaderDataChanged(Qt::Orientation orientation,
-                                    int start, int end);
-    void _q_sourceAboutToBeReset();
-    void _q_sourceReset();
-    void _q_clearMapping();
-    void _q_sourceLayoutAboutToBeChanged(const QList<QPersistentModelIndex> &sourceParents,
-                                         QAbstractItemModel::LayoutChangeHint hint);
-    void _q_sourceLayoutChanged(const QList<QPersistentModelIndex> &sourceParents,
-                                QAbstractItemModel::LayoutChangeHint hint);
-    void _q_sourceRowsAboutToBeInserted(const QModelIndex &source_parent,
-                                        int start, int end);
-    void _q_sourceRowsInserted(const QModelIndex &source_parent,
-                               int start, int end);
-    void _q_sourceRowsAboutToBeRemoved(const QModelIndex &source_parent,
-                                       int start, int end);
-    void _q_sourceRowsRemoved(const QModelIndex &source_parent,
-                              int start, int end);
-    void _q_sourceRowsAboutToBeMoved(const QModelIndex &sourceParent,
-                                     int sourceStart, int sourceEnd,
-                                     const QModelIndex &destParent, int dest);
-    void _q_sourceRowsMoved(const QModelIndex &sourceParent,
-                            int sourceStart, int sourceEnd,
-                            const QModelIndex &destParent, int dest);
-    void _q_sourceColumnsAboutToBeInserted(const QModelIndex &source_parent,
-                                           int start, int end);
-    void _q_sourceColumnsInserted(const QModelIndex &source_parent,
-                                  int start, int end);
-    void _q_sourceColumnsAboutToBeRemoved(const QModelIndex &source_parent,
-                                          int start, int end);
-    void _q_sourceColumnsRemoved(const QModelIndex &source_parent,
-                                 int start, int end);
-    void _q_sourceColumnsAboutToBeMoved(const QModelIndex &sourceParent,
-                                        int sourceStart, int sourceEnd,
-                                        const QModelIndex &destParent, int dest);
-    void _q_sourceColumnsMoved(const QModelIndex &sourceParent,
-                               int sourceStart, int sourceEnd,
-                               const QModelIndex &destParent, int dest);
-
-    const QAbstractProxyModel *proxyModel() const override { return q_func(); }
-    QModelIndex createIndex(int row, int column,
-                            QHash<QtPrivate::QModelIndexWrapper, QSortFilterProxyModelHelper::Mapping *>::const_iterator it) const override {
-        return create_index(row, column, it);
-    }
-    bool filterAcceptsRowInternal(int sourceRow, const QModelIndex &sourceIndex) const override;
-    bool filterAcceptsRow(int source_row, const QModelIndex &source_parent) const override {
-        return q_func()->filterAcceptsRow(source_row, source_parent);
-    }
-    bool filterAcceptsColumnInternal(int sourceColumn, const QModelIndex &sourceIndex) const override;
-    bool filterAcceptsColumn(int source_column, const QModelIndex &source_parent) const override {
-        return q_func()->filterAcceptsColumn(source_column, source_parent);
-    }
-    void sort_source_rows(QList<int> &source_rows, const QModelIndex &source_parent) const override;
-    bool lessThan(const QModelIndex &source_left, const QModelIndex &source_right) const override {
-        return q_func()->lessThan(source_left, source_right);
-    }
-
-    // Internal
-    QModelIndex m_lastTopSource;
-    QRowsRemoval m_itemsBeingRemoved;
-    bool m_completeInsert = false;
-    QModelIndexPairList m_savedPersistentIndexes;
-    QList<QPersistentModelIndex> m_savedLayoutChangeParents;
-    std::array<QMetaObject::Connection, 18> m_sourceConnections;
-    bool m_componentCompleted = false;
-
-    // Properties exposed to the user
-    QQmlFilterCompositor* m_filters;
-    QQmlSorterCompositor* m_sorters;
-    bool m_dynamicSortFilter = true;
-    bool m_recursiveFiltering = false;
-    bool m_autoAcceptChildRows = false;
-    int m_primarySortColumn = -1;
-    int m_proxySortColumn = -1;
-    Qt::SortOrder m_sortOrder = Qt::AscendingOrder;
-    QVariant m_sourceModel;
-};
-
 QQmlSortFilterProxyModel::QQmlSortFilterProxyModel(QObject *parent)
     : QAbstractProxyModel (*new QQmlSortFilterProxyModelPrivate, parent)
 {
@@ -605,7 +448,7 @@ QModelIndex QQmlSortFilterProxyModel::index(int row, int column, const QModelInd
     if (it.value()->source_rows.size() <= row || it.value()->source_columns.size() <= column)
         return QModelIndex();
 
-    return d->create_index(row, column, it);
+    return d->createIndex(row, column, it);
 }
 
 /*!
@@ -636,7 +479,7 @@ QModelIndex QQmlSortFilterProxyModel::sibling(int row, int column, const QModelI
     if (it.value()->source_rows.size() <= row || it.value()->source_columns.size() <= column)
         return QModelIndex();
 
-    return d->create_index(row, column, it);
+    return d->createIndex(row, column, it);
 }
 
 /*!
@@ -1333,14 +1176,14 @@ void QQmlSortFilterProxyModelPrivate::_q_sourceDataChanged(const QModelIndex &so
                        && m->proxy_columns.at(source_left_column) == -1)
                     ++source_left_column;
                 if (m->proxy_columns.at(source_left_column) != -1) {
-                    const QModelIndex proxy_top_left = create_index(
+                    const QModelIndex proxy_top_left = createIndex(
                             proxy_start_row, m->proxy_columns.at(source_left_column), it);
                     int source_right_column = source_bottom_right.column();
                     while (source_right_column > source_top_left.column()
                            && m->proxy_columns.at(source_right_column) == -1)
                         --source_right_column;
                     if (m->proxy_columns.at(source_right_column) != -1) {
-                        const QModelIndex proxy_bottom_right = create_index(
+                        const QModelIndex proxy_bottom_right = createIndex(
                                 proxy_end_row, m->proxy_columns.at(source_right_column), it);
                         emit q->dataChanged(proxy_top_left, proxy_bottom_right, roles);
                     }
@@ -1715,6 +1558,123 @@ bool QQmlSortFilterProxyModelPrivate::filterAcceptsColumnInternal(int row, const
     return q->filterAcceptsColumn(row, sourceIndex);
 }
 
+/*!
+    \internal
+ */
+QModelIndex QQmlSortFilterProxyModelPrivate::createIndex(int row, int column,
+    QHash<QtPrivate::QModelIndexWrapper, QSortFilterProxyModelHelper::Mapping *>::const_iterator it) const {
+    return q_func()->createIndex(row, column, *it);
+}
+
+/*!
+    \internal
+ */
+void QQmlSortFilterProxyModelPrivate::changePersistentIndexList(const QModelIndexList &from, const QModelIndexList &to) {
+    Q_Q(QQmlSortFilterProxyModel);
+    q->changePersistentIndexList(from, to);
+}
+
+/*!
+    \internal
+ */
+void QQmlSortFilterProxyModelPrivate::beginInsertRows(const QModelIndex &parent, int first, int last) {
+    Q_Q(QQmlSortFilterProxyModel);
+    q->beginInsertRows(parent, first, last);
+}
+
+/*!
+    \internal
+ */
+void QQmlSortFilterProxyModelPrivate::beginInsertColumns(const QModelIndex &parent, int first, int last) {
+    Q_Q(QQmlSortFilterProxyModel);
+    q->beginInsertColumns(parent, first, last);
+}
+
+/*!
+    \internal
+ */
+void QQmlSortFilterProxyModelPrivate::endInsertRows() {
+    Q_Q(QQmlSortFilterProxyModel);
+    q->endInsertRows();
+}
+
+/*!
+    \internal
+ */
+void QQmlSortFilterProxyModelPrivate::endInsertColumns() {
+    Q_Q(QQmlSortFilterProxyModel);
+    q->endInsertColumns();
+}
+
+/*!
+    \internal
+ */
+void QQmlSortFilterProxyModelPrivate::beginRemoveRows(const QModelIndex &parent, int first, int last) {
+    Q_Q(QQmlSortFilterProxyModel);
+    q->beginRemoveRows(parent, first, last);
+}
+
+/*!
+    \internal
+ */
+void QQmlSortFilterProxyModelPrivate::beginRemoveColumns(const QModelIndex &parent, int first, int last) {
+    Q_Q(QQmlSortFilterProxyModel);
+    q->beginRemoveColumns(parent, first, last);
+}
+
+/*!
+    \internal
+ */
+void QQmlSortFilterProxyModelPrivate::endRemoveRows() {
+    Q_Q(QQmlSortFilterProxyModel);
+    q->endRemoveRows();
+}
+
+/*!
+    \internal
+ */
+void QQmlSortFilterProxyModelPrivate::endRemoveColumns() {
+    Q_Q(QQmlSortFilterProxyModel);
+    q->endRemoveColumns();
+}
+
+/*!
+    \internal
+ */
+void QQmlSortFilterProxyModelPrivate::beginResetModel() {
+    Q_Q(QQmlSortFilterProxyModel);
+    q->beginResetModel();
+}
+
+/*!
+    \internal
+ */
+void QQmlSortFilterProxyModelPrivate::endResetModel() {
+    Q_Q(QQmlSortFilterProxyModel);
+    q->endResetModel();
+}
+
+/*!
+    \internal
+ */
+bool QQmlSortFilterProxyModelPrivate::filterAcceptsRow(int source_row, const QModelIndex &source_parent) const {
+    return q_func()->filterAcceptsRow(source_row, source_parent);
+}
+
+/*!
+    \internal
+ */
+bool QQmlSortFilterProxyModelPrivate::filterAcceptsColumn(int source_column, const QModelIndex &source_parent) const {
+    return q_func()->filterAcceptsColumn(source_column, source_parent);
+}
+
+/*!
+    \internal
+ */
+bool QQmlSortFilterProxyModelPrivate::lessThan(const QModelIndex &source_left, const QModelIndex &source_right) const {
+    return q_func()->lessThan(source_left, source_right);
+}
+
 QT_END_NAMESPACE
 
 #include "moc_qqmlsortfilterproxymodel_p.cpp"
diff --git a/src/qmlmodels/sfpm/qqmlsortfilterproxymodel_p_p.h b/src/qmlmodels/sfpm/qqmlsortfilterproxymodel_p_p.h
new file mode 100644
index 0000000000..17da0bd949
--- /dev/null
+++ b/src/qmlmodels/sfpm/qqmlsortfilterproxymodel_p_p.h
@@ -0,0 +1,131 @@
+// Copyright (C) 2025 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#ifndef QQMLSORTFILTERPROXYMODEL_P_P_H
+#define QQMLSORTFILTERPROXYMODEL_P_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtCore/qitemselectionmodel.h>
+#include <QtQml/private/qqmlcustomparser_p.h>
+#include <QtQmlModels/private/qtqmlmodelsglobal_p.h>
+#include <QtQmlModels/private/qsortfilterproxymodelhelper_p.h>
+#include <QtQmlModels/private/qqmlsortfilterproxymodel_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class QQmlSortFilterProxyModelPrivate : public QAbstractProxyModelPrivate, public QSortFilterProxyModelHelper
+{
+    Q_DECLARE_PUBLIC(QQmlSortFilterProxyModel)
+
+public:
+    void init();
+
+    bool containRoleForRecursiveFilter(const QList<int> &roles) const;
+    bool recursiveParentAcceptsRow(const QModelIndex &source_parent) const;
+    bool recursiveChildAcceptsRow(int source_row, const QModelIndex &source_parent) const;
+
+    QList<std::pair<int, QList<int>>> proxy_intervals_for_source_items_to_add(
+            const QList<int> &proxy_to_source, const QList<int> &source_items,
+            const QModelIndex &source_parent, QSortFilterProxyModelHelper::Direction direction) const override;
+    bool needsReorder(const QList<int> &source_rows, const QModelIndex &source_parent) const;
+    bool updatePrimaryColumn();
+    int findPrimarySortColumn() const;
+
+    void changePersistentIndexList(const QModelIndexList &from, const QModelIndexList &to) override;
+    void beginInsertRows(const QModelIndex &parent, int first, int last) override;
+    void beginInsertColumns(const QModelIndex &parent, int first, int last) override;
+    void endInsertRows() override;
+    void endInsertColumns() override;
+    void beginRemoveRows(const QModelIndex &parent, int first, int last) override;
+    void beginRemoveColumns(const QModelIndex &parent, int first, int last) override;
+    void endRemoveRows() override;
+    void endRemoveColumns() override;
+    void beginResetModel() override;
+    void endResetModel() override;
+
+    // Update the proxy model when there is any change in the source model
+    void _q_sourceDataChanged(const QModelIndex &source_top_left,
+                              const QModelIndex &source_bottom_right,
+                              const QList<int> &roles);
+    void _q_sourceHeaderDataChanged(Qt::Orientation orientation,
+                                    int start, int end);
+    void _q_sourceAboutToBeReset();
+    void _q_sourceReset();
+    void _q_clearMapping();
+    void _q_sourceLayoutAboutToBeChanged(const QList<QPersistentModelIndex> &sourceParents,
+                                         QAbstractItemModel::LayoutChangeHint hint);
+    void _q_sourceLayoutChanged(const QList<QPersistentModelIndex> &sourceParents,
+                                QAbstractItemModel::LayoutChangeHint hint);
+    void _q_sourceRowsAboutToBeInserted(const QModelIndex &source_parent,
+                                        int start, int end);
+    void _q_sourceRowsInserted(const QModelIndex &source_parent,
+                               int start, int end);
+    void _q_sourceRowsAboutToBeRemoved(const QModelIndex &source_parent,
+                                       int start, int end);
+    void _q_sourceRowsRemoved(const QModelIndex &source_parent,
+                              int start, int end);
+    void _q_sourceRowsAboutToBeMoved(const QModelIndex &sourceParent,
+                                     int sourceStart, int sourceEnd,
+                                     const QModelIndex &destParent, int dest);
+    void _q_sourceRowsMoved(const QModelIndex &sourceParent,
+                            int sourceStart, int sourceEnd,
+                            const QModelIndex &destParent, int dest);
+    void _q_sourceColumnsAboutToBeInserted(const QModelIndex &source_parent,
+                                           int start, int end);
+    void _q_sourceColumnsInserted(const QModelIndex &source_parent,
+                                  int start, int end);
+    void _q_sourceColumnsAboutToBeRemoved(const QModelIndex &source_parent,
+                                          int start, int end);
+    void _q_sourceColumnsRemoved(const QModelIndex &source_parent,
+                                 int start, int end);
+    void _q_sourceColumnsAboutToBeMoved(const QModelIndex &sourceParent,
+                                        int sourceStart, int sourceEnd,
+                                        const QModelIndex &destParent, int dest);
+    void _q_sourceColumnsMoved(const QModelIndex &sourceParent,
+                               int sourceStart, int sourceEnd,
+                               const QModelIndex &destParent, int dest);
+
+    const QAbstractProxyModel *proxyModel() const override { return q_func(); }
+    QModelIndex createIndex(int row, int column,
+                            QHash<QtPrivate::QModelIndexWrapper, QSortFilterProxyModelHelper::Mapping *>::const_iterator it) const override;
+    bool filterAcceptsRowInternal(int sourceRow, const QModelIndex &sourceIndex) const override;
+    bool filterAcceptsRow(int source_row, const QModelIndex &source_parent) const override;
+    bool filterAcceptsColumnInternal(int sourceColumn, const QModelIndex &sourceIndex) const override;
+    bool filterAcceptsColumn(int source_column, const QModelIndex &source_parent) const override;
+    void sort_source_rows(QList<int> &source_rows, const QModelIndex &source_parent) const override;
+    bool lessThan(const QModelIndex &source_left, const QModelIndex &source_right) const override;
+
+    // Internal
+    QModelIndex m_lastTopSource;
+    QRowsRemoval m_itemsBeingRemoved;
+    bool m_completeInsert = false;
+    QModelIndexPairList m_savedPersistentIndexes;
+    QList<QPersistentModelIndex> m_savedLayoutChangeParents;
+    std::array<QMetaObject::Connection, 18> m_sourceConnections;
+    bool m_componentCompleted = false;
+
+    // Properties exposed to the user
+    QQmlFilterCompositor* m_filters;
+    QQmlSorterCompositor* m_sorters;
+    bool m_dynamicSortFilter = true;
+    bool m_recursiveFiltering = false;
+    bool m_autoAcceptChildRows = false;
+    int m_primarySortColumn = -1;
+    int m_proxySortColumn = -1;
+    Qt::SortOrder m_sortOrder = Qt::AscendingOrder;
+    QVariant m_sourceModel;
+};
+
+QT_END_NAMESPACE
+
+#endif // QQMLSORTFILTERPROXYMODEL_P_P_H
diff --git a/src/qmlmodels/sfpm/sorters/qqmlsortercompositor.cpp b/src/qmlmodels/sfpm/sorters/qqmlsortercompositor.cpp
index 4409b8c3e3..7b8ebca7e6 100644
--- a/src/qmlmodels/sfpm/sorters/qqmlsortercompositor.cpp
+++ b/src/qmlmodels/sfpm/sorters/qqmlsortercompositor.cpp
@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
 #include <QtQmlModels/private/qqmlsortercompositor_p.h>
+#include <QtQmlModels/private/qqmlsortfilterproxymodel_p_p.h>
 #include <QtQmlModels/private/qqmlsortfilterproxymodel_p.h>
 
 QT_BEGIN_NAMESPACE
@@ -181,8 +182,10 @@ bool QQmlSorterCompositor::lessThan(const QModelIndex& sourceLeft, const QModelI
             const QPartialOrdering result = sorter->compare(sourceModel->index(sourceLeft.row(), sortSection),
                                                             sourceModel->index(sourceRight.row(), sortSection),
                                                             proxyModel);
-            if ((result == QPartialOrdering::Less) || (result == QPartialOrdering::Greater))
-                return (result < 0);
+            if (result == QPartialOrdering::Less || result == QPartialOrdering::Greater) {
+                auto *priv = static_cast<const QQmlSortFilterProxyModelPrivate *>(QQmlSortFilterProxyModelPrivate::get(proxyModel));
+                return (priv->m_sortOrder == sorter->sortOrder()) ? result < 0 : result > 0;
+            }
         }
     }
     // Verify the index order when the ordering is either equal or unordered