Quote Originally Posted by prasad_N View Post
rowCount() is calling for all the top level items in a view, is it a default behavior of model ?
No, it's a default behaviour of QTreeView since the tree wants to know whether each of the items has child items.

If so, can we change this so that it will get called only for currently viewing items in view.
Hmm... I don't think the view cares about items that are not visible unless you asked items to be expanded, in which case it needs to calculate the total size of the tree for the scrollbar.