QConcatenateTablesProxyModel: Add getter for sourceModels

Currently, there's no generic way to get the source models as there's only
calls to add or remove them.

Change-Id: I23cdef7c93328b58a80ec4659b44073f8ff05088
Reviewed-by: David Faure <david.faure@kdab.com>

src/corelib/itemmodels/qconcatenatetablesproxymodel.cpp

@@ -447,6 +447,17 @@ QSize QConcatenateTablesProxyModel::span(const QModelIndex &index) const
     return sourceIndex.model()->span(sourceIndex);
 }
 
+/*!
+    Returns a list of models that were added as source models for this proxy model.
+
+    \since 5.15
+*/
+QList<QAbstractItemModel *> QConcatenateTablesProxyModel::sourceModels() const
+{
+    Q_D(const QConcatenateTablesProxyModel);
+    return d->m_models.toList();
+}
+
 /*!
     Adds a source model \a sourceModel, below all previously added source models.
 

src/corelib/itemmodels/qconcatenatetablesproxymodel.h

@@ -56,6 +56,7 @@ public:
     explicit QConcatenateTablesProxyModel(QObject *parent = nullptr);
     ~QConcatenateTablesProxyModel();
 
+    QList<QAbstractItemModel *> sourceModels() const;
     Q_SCRIPTABLE void addSourceModel(QAbstractItemModel *sourceModel);
     Q_SCRIPTABLE void removeSourceModel(QAbstractItemModel *sourceModel);