Just for the record:
I found the solution on the net: http://wilshipley.com/blog/2006/04/pimp-my-code-part-10-whining-about.html
. But instead of going through the whole tree to find an object, I
simply store the complete object hierarchy, so that I only have to
descent to that children,
I have a NSTreeController which is connected to a NSOutlineView. I
wish to have links to specific entries in the NSTreeController. With
these links I want to select those items. I therefore use the
NSIndexPath. Unfortunately the NSIndexPath becomes invalid if the sort
order is changed by
