QConcatenateTablesProxyModel: implement roleNames()

Change-Id: Id74b45f58678df15285c8b9631db1c59a5d62a2a
Reviewed-by: Santhosh Kumar <santhosh.kumar.selvaraj@qt.io>
(cherry picked from commit 5ffb9d7ae6d60fb370b79f8222dab7d7e628fa4f)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

src/corelib/itemmodels/qconcatenatetablesproxymodel.cpp

@@ -540,6 +540,23 @@ void QConcatenateTablesProxyModel::removeSourceModel(QAbstractItemModel *sourceM
     d->updateColumnCount();
 }
 
+/*!
+    \since 6.9.0
+    \reimp
+    Returns the union of the roleNames() of the underlying models.
+
+    In case source models associate different names to the same role,
+    the name used in last source model overrides the name used in earlier models.
+*/
+QHash<int, QByteArray> QConcatenateTablesProxyModel::roleNames() const
+{
+    Q_D(const QConcatenateTablesProxyModel);
+    QHash<int, QByteArray> ret = QAbstractItemModel::roleNames();
+    for (const auto &[model, _] : d->m_models)
+        ret.insert(model->roleNames());
+    return ret;
+}
+
 void QConcatenateTablesProxyModelPrivate::slotRowsAboutToBeInserted(const QModelIndex &parent,
                                                                     int start, int end)
 {

src/corelib/itemmodels/qconcatenatetablesproxymodel.h

@@ -42,6 +42,7 @@ public:
     bool canDropMimeData(const QMimeData *data, Qt::DropAction action, int row, int column, const QModelIndex &parent) const override;
     bool dropMimeData(const QMimeData *data, Qt::DropAction action, int row, int column, const QModelIndex &parent) override;
     QSize span(const QModelIndex &index) const override;
+    QHash<int, QByteArray> roleNames() const override;
 
 private:
     Q_DECLARE_PRIVATE(QConcatenateTablesProxyModel)

src/gui/itemmodels/qstandarditemmodel.cpp

@@ -2251,7 +2251,7 @@ void QStandardItemModel::setItemRoleNames(const QHash<int,QByteArray> &roleNames
 }
 
 /*!
-  reimp
+  \reimp
 */
 QHash<int, QByteArray> QStandardItemModel::roleNames() const
 {

tests/auto/corelib/itemmodels/qconcatenatetablesproxymodel/tst_qconcatenatetablesproxymodel.cpp

@@ -86,6 +86,8 @@ private Q_SLOTS:
     void qtbug91788();
     void qtbug91878();
     void createPersistentOnLayoutAboutToBeChanged();
+    void shouldMergeRoleNames();
+
 private:
     QStandardItemModel mod;
     QStandardItemModel mod2;
@@ -99,11 +101,13 @@ void tst_QConcatenateTablesProxyModel::init()
     mod.appendRow({ new QStandardItem(QStringLiteral("A")), new QStandardItem(QStringLiteral("B")), new QStandardItem(QStringLiteral("C")) });
     mod.setHorizontalHeaderLabels(QStringList() << QStringLiteral("H1") << QStringLiteral("H2") << QStringLiteral("H3"));
     mod.setVerticalHeaderLabels(QStringList() << QStringLiteral("One"));
+    mod.setItemRoleNames({ { Qt::UserRole, "user" } });
 
     mod2.clear();
     mod2.appendRow({ new QStandardItem(QStringLiteral("D")), new QStandardItem(QStringLiteral("E")), new QStandardItem(QStringLiteral("F")) });
     mod2.setHorizontalHeaderLabels(QStringList() << QStringLiteral("H1") << QStringLiteral("H2") << QStringLiteral("H3"));
     mod2.setVerticalHeaderLabels(QStringList() << QStringLiteral("Two"));
+    mod2.setItemRoleNames({ { Qt::UserRole + 1, "user+1" } });
 
     mod3.clear();
     mod3.appendRow({ new QStandardItem(QStringLiteral("1")), new QStandardItem(QStringLiteral("2")), new QStandardItem(QStringLiteral("3")) });
@@ -927,6 +931,23 @@ void tst_QConcatenateTablesProxyModel::createPersistentOnLayoutAboutToBeChanged(
     QCOMPARE(layoutChangedSpy.size(), 1);
 }
 
+void tst_QConcatenateTablesProxyModel::shouldMergeRoleNames()
+{
+    // Given a combining proxy
+    QConcatenateTablesProxyModel pm;
+
+    // When adding three source models
+    pm.addSourceModel(&mod);
+    pm.addSourceModel(&mod2);
+    pm.addSourceModel(&mod3);
+
+    // Then the role names should be merged
+    const auto roleNames = pm.roleNames();
+    QCOMPARE(roleNames[Qt::DisplayRole], "display");
+    QCOMPARE(roleNames[Qt::UserRole], "user");
+    QCOMPARE(roleNames[Qt::UserRole + 1], "user+1");
+}
+
 QTEST_GUILESS_MAIN(tst_QConcatenateTablesProxyModel)
 
 #include "tst_qconcatenatetablesproxymodel.moc"