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Path: utzoo!utgpu!utcsri!flaps
From: flaps@utcsri.UUCP
Newsgroups: comp.sys.amiga
Subject: Re: Workbench "multiple-files" or "attached-files" icons
Message-ID: <4615@utcsri.UUCP>
Date: Sat, 18-Apr-87 17:01:39 EST
Article-I.D.: utcsri.4615
Posted: Sat Apr 18 17:01:39 1987
Date-Received: Sat, 18-Apr-87 19:00:26 EST
References: <1176@spice.cs.cmu.edu> <1685@husc6.UUCP>
Reply-To: flaps@utcsri.UUCP (Alan J Rosenthal)
Organization: University of Toronto
Lines: 36
Summary: 

In article <1685@husc6.UUCP> hadeishi@husc7.UUCP (Mitsuharu Hadeishi) writes:
:>In Re-hash:  I proposed a addition to the standard Workbench icon,
:> the "attached-files" icon, which would basically be a single icon
:> which could refer to multiple files, even directories of files.

:>A possible glitch with my attached-files icon scheme for Workbench
:>is the following:  someone may create a library shared by several
:>applications, but a data directory used by only one application.
:>You'd have to be careful not to have more than one icon have
:>an overlapping set of attached files; if you did this, then if
:>the user deleted one of the icons, the attached files for that icon
:>would go away, but the other icon would still be there, and yet
:>the application related to that icon would not work.  This is Not Good.
:>Users would go mad, get angry, arrrgh . . .  Anyway, the solution
:>is simply to tell designers to only group together support files
:>to be referenced by a multiple-file icon if they ALWAYS GO TOGETHER.

Why not simply have a reference count?  Store in the file header something
saying "I am attached to x attached-files-icons."  Then when you delete
an attached-files-icon, decrement all reference counts & delete only the
files which hit 0.

Of course then your application would have to respect the file headers.
This would preclude using some existing applications, but I think that
this would work well with new applications designed for use with this
mechanism.  Old applications would just have to use your solution above.

-- 

Alan J Rosenthal

flaps@csri.toronto.edu, {seismo!utai or utzoo}!utcsri!flaps,
flaps@toronto on csnet, flaps at utorgpu on bitnet.

"Probably the best operating system in the world is the [operating system]
made for the PDP-11 by Bell Laboratories." - Ted Nelson, October 1977