else {
Q_ASSERT(topLeftItem && bottomRightItem);
sourceSelection << QItemSelectionRange(mapToSource(createIndex(topLeftItem->pos(), left, topLeftItem)), mapToSource(createIndex(bottomRightItem->pos(), right, bottomRightItem)));
else {
Q_ASSERT(topLeftItem && bottomRightItem);
sourceSelection << QItemSelectionRange(mapToSource(createIndex(topLeftItem->pos(), left, topLeftItem)), mapToSource(createIndex(bottomRightItem->pos(), right, bottomRightItem)));