Path: utzoo!attcan!uunet!husc6!bbn!bbn.com!levin
From: levin@bbn.com (Joel B Levin)
Newsgroups: comp.sys.mac.programmer
Subject: Re: What do InitGraf (etc) do?
Message-ID: <32617@bbn.COM>
Date: 22 Nov 88 15:35:00 GMT
References: <987@etive.ed.ac.uk> <988@etive.ed.ac.uk>
Sender: news@bbn.COM
Reply-To: levin@BBN.COM (Joel B Levin)
Organization: BBN Communications Corporation
Lines: 27

In article <988@etive.ed.ac.uk> nick@lfcs.ed.ac.uk (Nick Rothwell) writes:
|A short and sweet question: Why do my programs have to call InitGraf(),
|InitTE(), InitDialogs() and all the rest of this stuff?
|   A Macintosh sitting in the Finder is running QuickDraw, putting up dialogs,
|and so on, so "initialisation" in that sense is surely unnecessary? Does it
|make sense to initialise a manager more than once?
(I'm sure you'll get lots of answers...)

Some "global" managers are, in fact, initialized once, e.g. the
resource manager, memory manager, etc ... Inside Mac spells this out
for each appropriate manager ("The application should never need to do
this" type of comment).  Other managers deal with structures and
processes "local" to the application and its heap.  InitGraf
initializes the QD globals for the application, clears the screen to
the default desktop pattern(*), resets the cursor, etc. -- note how
all this always happens when a new application is launched.  So
InitGraf and initialization procedures for all the managers dependent
on QD need to be called every time the application heap is
initialized.

	/JBL

(*) While this does not all happen under MultiFinder, each application
has its own heap and QD globals, so InitGraf is still needed.

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