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From: torrie@cs.stanford.edu (Evan J Torrie)
Newsgroups: comp.sys.amiga.advocacy
Subject: Re: Hooks into the OS vs doing it all yourself (Was Re: Clueless Mac<>)
Message-ID: <1991Jan31.011702.12095@Neon.Stanford.EDU>
Date: 31 Jan 91 01:17:02 GMT
References: <1991Jan21.004720.25985@ncsuvx.ncsu.edu> <12880@life.ai.mit.edu> <1991Jan21.172643.20642@Neon.Stanford.EDU> <7594@sugar.hackercorp.com> <1991Jan25.075446.716@Neon.Stanford.EDU> <7658@sugar.hackercorp.com>
Sender: torrie@Neon.Stanford.EDU (Evan James Torrie)
Distribution: usa
Organization: Computer Science Department, Stanford University
Lines: 47

peter@sugar.hackercorp.com (Peter da Silva) writes:

>In article <1991Jan25.075446.716@Neon.Stanford.EDU> torrie@cs.stanford.edu (Evan J Torrie) writes:
>>   What kind of hooks does the Amiga have into the OS for things that
>> are handled "automagically"?  e.g. I recall that when a window gets
>> resized, the OS handles everything for you [mouse tracking? window
>> outline? new window frame?] and just sends you a "Window Changed"
>> message.

>Yep.

>>   Can your program get its hooks into this event BEFORE the OS gets
>> hold of it and "do its own thing"?

>Nope. You can tell Intuition the bounds you're willing to let the user manage
>the window within, but that's it.

  Well this will probably cause some flames, but this is an example of
where the Mac is MORE customizable than the Amiga... i.e. where the
user can make things work the way he wants, not the way the OS wants.
  I am reminded of a quote in Steve Chernicoff's Macintosh Revealed
book... paraphrasing, he said something like "When Apple released the
Macintosh 128K, critics pounded it for being a closed system.  While
their criticisms of the hardware were well-founded, what they didn't
realise was that the Macintosh had an almost completely open software
design".
  For example, all the hooks into window definition functions, menu
definition functions, etc... where you can roll your own code, and
make your own windows/menus etc... this is how the Mac gets all those
nice NeXT/Motif type windows without having to rewrite existing
program code.
  While it means you may have to write more code to handle the general
case, it gives you more control over the final result as well.   

>Amiga scrollbars (proportional gadgets) don't have arrows. If you see an arrow
>the application is managing two gadgets together. But if you want to know how
>Intuition (which, by the way, is not the O/S, it's just another task) knows how
>far you can frag a scrollbar with the mouse, I can tell you that: the
>application tells it how far it can move the knob.

  Can you have callback functions.. i.e. get Intuition to call your
function while it's moving the knob?

-- 
------------------------------------------------------------------------------
Evan Torrie.  Stanford University, Class of 199?       torrie@cs.stanford.edu   
Today's maxim:  All socialists are failed capitalists