Oh my, how did I overlook that ;-)

Indeed, the summary by Andreas is clear and very helpful:
  http://wiki.squeak.org/squeak/6647

Dave


On Tue, Nov 17, 2020 at 07:53:24PM +0100, Jakob Reschke wrote:
> 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:
> 
>   http://wiki.squeak.org/squeak/6647
> 
> 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.
> 
> Dave
> 
> 
> 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
> >
> >
> >

>