[ANN] Pointer Detective

greetings all,

I had an itch to scratch...  I find it difficult using the tree list of
the standard Pointer Explorer to track down why objects aren't garbage
collected.  I always fear I'm not going to notice getting caught in a
reference loop.  So I created a tool presenting an alternative view as a
directed graph.  The graph incrementally builds out from the target
object as you explore it. Nodes are colourised to help manage complexity.

The attached snapshot is produced from evaluating the following
Workspace script...
    testObject := 'END5'.
    ref1 := { testObject. nil }.
    ref2 := { ref1 }.
    ref3 := PDTestResource new heldObject: ref2.
    ref1 at: 2 put: ref3.  "note the reference loop this creates"
    PointerDetective openOn: testObject.

Now I expect I'm duplicating something done before, but I couldn't find
anything quickly and it was an opportunity for some goal direct learning
of Morphic. Thanks to Roassal an option for a spring-force layout is
provided. That code was copied rather than create a dependency, and
might need to be rationalized later.

The code is a bit rough from hacking around learning how to make things
work, but its functional, so its time to get it out in the open.

For more information please refer to the repository home page...
http://smalltalkhub.com/#!/~BenComan/PointerDetective

cheers -ben