Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!uunet!mcsun!unido!tub!db0tui11!MUHRTH
From: MUHRTH@DB0TUI11.BITNET (Thomas Muhr)
Newsgroups: comp.lang.smalltalk
Subject: Two (independent) views on same model - how?
Message-ID: <469@DB0TUI11.BITNET>
Date: 14 Dec 89 09:40:47 GMT
Reply-To: MUHRTH@DB0TUI11.BITNET (Thomas Muhr)
Organization: TU Berlin
Lines: 27
Disclaimer: Author bears full responsibility for contents of this article

I have posted this problem together with a bundle of others a few weeks ago
and kindly received answers, of which one is leading right to the 'guts'
of Smalltalk V/286,which meant considering the use of - from my point of
view - very lowlevel-methods like dropSenderChain and the like. The question
today is looking for more comprehensible solutions for the following problem:
When opening another view in an overlapping-window fashion as result of a
menu selection of the underlying view already open on the specific model, every
thing seems to be ok until closing the last view: All dependencies are re-
leased between the model and ALL existing views, not - as I would prefer -
the dependencies between the closing view and the model only.
First I thought, that's easy, I just deactivate the release-method by rede-
fining it (empty) in my model, but that lead to enormous dependency-lists
growing with every invocation of an overlapping view! What I have done now is
Havin a menu-selection 'refresh' which rebuilds the dependency-list from a
special instancevariable, which stores the dependencies at the time of the
primary invocation. But this is really not a very clean approach and I would
be very happy if someone would provide me with a straightforward solution
which doesn't make a dozen more knots into the spaghetti already implicit in
the model-dispatcher-pane interrelations.
Thanks very much in advance-
Thomas

-------
Thomas Muhr, Technical University of Berlin, BITNET: muhrth@db0tui11
   Project ATLAS - Computer Based Tools for Qualitative Research
         "Computers, like every technology, are a vehicle
     for the transformation of tradition." (WINOGRAD/FLORES)