Question about NSOutlineView and NSTreeController

FROM : Jeff LaMarche
DATE : Wed Apr 02 19:03:08 2008

I posted a question yesterday, and some of the responses were very 
helpful (thanks, by the way), but also showed me I didn't fully 
understand what I needed to ask. After several more hours of 
exploration last night, I think I have a grasp on my real question. My 
problem comes down to this (I think): when no item is selected in the 
an outline view, the tree controller instance that it is bound to 
still returns an array for selectedObjects with objects in it, and 
when binding the content set of another controller to that tree 
controller's selection key, the other controller shows data as if 
something were still selected in the tree controller.

Essentially, I have three views - the main NSOutlineView with a tree 
controller, and then I have two subordinate views, each of which shows 
items relative to the selected root object in the main NSOutlineView, 
one shows them hierarchically in an NSOutlineView, and the other shows 
a flat, alphabetized list of the same objects using an NSTableView. 
There is a different association from the root object for each of 
these views.  Both of these subordinate views have their own 
controllers, and they work just fine, except that when the main 
NSOutlineView has nothing selected, but previously did, the two 
subordinate views should show nothing, but they seem to show the data 
from the last selection; the Tree Controller doesn't seem to be aware 
that there is nothing selected in the outline view bound to it.

Am I, perhaps, doing something wrong here, or is there some setting I 
can set to cause the tree controller to get informed by the outline 
view when nothing is selected? If not, is there some accepted way of 
doing this? Or have I stumbled across an honest-to-goodness bug and 
should file a bug report?

Thanks much,
Jeff