The error turned out to be that the tree participates in the change- 
update mechanism which causes infinite recursion. To wit:
- Calling #selectedItem: in the model tells the tree that  
#selectedItemPath has updated
- The tree updates its path and then *by design* sends #selectedItem:  
to the model

In order to avoid a deadlock, a ~~ test in #selectedItem: on the new- 
and-old values guards against further change-notification.

I am unsure what better pattern to use, since none of the other  
ToolBuilder-using tools uses another widget to update their trees.  
Perhaps it is a bug?

In any case, I'll release my fixes shortly.

On Nov 24, 2006, at 4:42 PM, Brian Rice wrote:

> Unfortunately, after making this refactoring, I still have the same  
> problem. I'll elaborate:
> - I removed any uses of ItemWrappers.
> - I changed the #selectedItemWrapperPath to #selectedItemPath,  
> returning an Array of the same labels used to build the tree to  
> begin with.
> - There was a variation in terms of bolding some strings, making  
> them Texts, but removing this variation did not change the outcome  
> (requiring a user-halt).
>
> What I'm reading implicitly is that the path needs to be a sequence  
> of the keys used to drill down to the item. That it is not the  
> sequence of objects themselves stored with those keys. It seems to  
> bear out with the usage, but maybe I'm way off base for reasons of  
> misinterpretation.
>
> When I call "self changed: #selectedItemPath", I get a lock-up  
> which I have to halt which puts me in a stack with  
> PluggableTreeMorph>>update: (on #selectedItemPath) and  
> Array>>at:ifAbsent: at the top.
>

--
-Brian
http://briantrice.com

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