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, 35 insertions, 0 deletions

diff --git a/doc/src/snippets/code/src_corelib_kernel_qabstractitemmodel.cpp b/doc/src/snippets/code/src_corelib_kernel_qabstractitemmodel.cpp
index 5919c01085..cf40f9a05a 100644
--- a/doc/src/snippets/code/src_corelib_kernel_qabstractitemmodel.cpp
+++ b/doc/src/snippets/code/src_corelib_kernel_qabstractitemmodel.cpp
@@ -86,3 +86,38 @@ beginMoveRows(parent, 2, 2, parent, 0);
 //! [9]
 beginMoveRows(parent, 2, 2, parent, 4);
 //! [9]
+
+
+//! [10]
+class CustomDataProxy : public QSortFilterProxyModel
+{
+    Q_OBJECT
+public:
+    CustomDataProxy(QObject *parent)
+      : QSortFilterProxyModel(parent)
+    {
+    }
+
+    ...
+
+    QVariant data(const QModelIndex &index, int role)
+    {
+        if (role != Qt::BackgroundRole)
+            return QSortFilterProxyModel::data(index, role);
+
+        if (m_customData.contains(index.row()))
+            return m_customData.value(index.row());
+        return QSortFilterProxyModel::data(index, role);
+    }
+
+private slots:
+    void resetInternalData()
+    {
+        m_customData.clear();
+    }
+
+private:
+  QHash<int, QVariant> m_customData;
+};
+//! [10]
+