message: no need to recalculate, it is just the number of the upper parents
diff: @@ -140,7 +140,7 @@ void TreeView::collapseAll()
  mSupressItemExpandStateChanged = true;
  QTreeView::collapseAll();
  mSupressItemExpandStateChanged = false;
  - setCollapseCount(countCollapsed());
  + setCollapseCount(model()->rowCount());
  }
  void TreeView::itemExpanded(const QModelIndex& index)
  