[squeak-dev] Worlds in Worlds are NOT completely dead?! ????

Jakob Reschke forums.jakob at resfarm.de
Tue Nov 17 18:53:24 UTC 2020

Don't forget your own email from September:

---------- Forwarded message ---------
Von: *David T. Lewis* <lewis at mail.msen.com>
Date: So., 20. Sep. 2020, 17:50
Subject: [squeak-dev] ActiveGlobals explained by Andreas Raab
To: <squeak-dev at lists.squeakfoundation.org>

In the course of trying to better understand the role of the ActiveHand
global, I found an excellent explanation by Andreas Raab in his original
change set. I put this on the swiki and linked it to several related pages:


It is amusing to note how I found this. I was trying to figure out what
object should properly own the active hand, and I had conviced myself
that it should probably be the WolrdState for a Morphic world.

So as an experiment, it tried adding the instance variable to WorldState,
and I discovered to my surprise that it was already there. It was completely
unreferenced, but one of my Morphic worlds still had it set to point to
a HandMorph, which seemed odd.

Looking back at old images, I found that the activeHand instance var in
WorldState was last used in Squeak 3.0, and that the global variable that
replaced it was in use as of Squeak 3.10.2.

A bit of digging though the files.squeak.org archives led me to the
original change set in which the change was made. Andreas provided a
preamble with explanation of the rationale for the change, this this
is what I copied to the swiki.

Despite the fact that a WorldState instance still point to an activeHand,
that reference has apparently been hanging around for the last 20 years
without actually being used for anything.


David T. Lewis <lewis at mail.msen.com> schrieb am Di., 17. Nov. 2020, 17:26:

> On Tue, Nov 17, 2020 at 01:41:37PM +0000, Douglas Brebner wrote:
> >
> > On 17/11/2020 01:11, David T. Lewis wrote:
> > >- ActiveHand. This is meaningful only to a Morphic project and
> > >presumably can be refactored to eliminate the global.
> >
> > How does this interact with multiple hands?
> >
> That question, and others like it, are exactly what needs to be understood
> (and hopefully documented) before attempting any surgery on the system :-)
> There are a few pages on the swiki that provide some context. This one
> is a good starting point:
>   http://wiki.squeak.org/squeak/118
> Dave
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.squeakfoundation.org/pipermail/squeak-dev/attachments/20201117/cc33a97e/attachment.html>

More information about the Squeak-dev mailing list