Mac-Source 1994 July/Mac-Source_July_1994.iso/Information/beginning-mac-programming.txt

Internet Message Format | 1994-03-23 | 16KB

Date: Thu, 04 Jan 90 08:56:05 EST
From: [e-mail]
Subject: SUMMARY: Intro Material for Mac Resources & Programming

Date: 4 January 1990, 08:43:49 EST
>From: KESLER   at OUACCVMA
To:   INFO-MAC at SUMEX-AIM.STANFORD.EDU

Dear Moderators,

I'm not sure whether I should have sent this as mail or not, but here goes.
The following article is an edited collection of information that I
received in answer to my request for details regarding some beginning level
info on Macintosh Resources and Programming.  At the end of the summary
is a *reading list*, of sorts, for those who want to delve deeper.
I received a number of requests for this summary so I believe there may be
many more out there who could use the info.  I suggest, because of its
length, that you put it in the archives somewhere instead of inserting it
into an issue of the digest.  The article is just in standard ASCII.


----------------------------------------------------
SUMMARY:  MACINTOSH PROGRAMMING AND RESOURCE PRIMERS
----------------------------------------------------

I want to thank all of you who sent replies to my questions
about Introductory materials for Macintosh programing and
resources.  What follows is a spruced up version of what I
received; something between a summary and a straight
anthology of replies.  Forgive me if I mis-edited or deleted some
information you sent to me.  It's DANGEROUS to let the novice in
the group do the summary, but someone has to stand up for the
little people!

The impression I got from these replies is that there is stuff
out there for everyone -- from those who want (like me) to
dabble, and those who want to do this sort of thing
professionally, and everyone in between.  I have added a reading
list to the end of this summary for those who requested it.


GREETINGS NETLANDERS!

My curiosity has gotten the best of me and, like an increasing
number of you, I want to do more than just *use* applications
on my MAC -- I want to take them apart, make changes, and
maybe even write a few myself!  What I need is some sort of
primer or introduction to a lot of the terminology that I see
posted here.  Where does someone familiar with programing in
the IBM world begin a trek into MacLand?  Here are a few
questions for starters:

1) WHAT ARE *RESOURCES* IN MACINTOSH TERMINOLOGY?  WHAT DO
   THEY DO?  HOW ARE THEY USED AND MANIPULATED?

2) In reference to many postings to the archives I see the
   acronym MPW quite a bit.  I know it has something to do with
   programing and languages (is it a language?) but I'm not sure.

3) There are many references to a utility program called ResEdit
   and other similar programs.  Where can I get this program?
   How much does it cost?  Who sells it?

4) In short, where is a good place to begin learning how it all
   works? I'm especially interested in introductory or beginning
   materials.

--------------------------
RESOURCES
--------------------------

you have really opened a can of worms for yourself.

Resources:  Everything on the Macintosh is a resource.  Actually,
that isn't entirely true, but close enough.  Programs consist of
CODE resources that load WIND resources and open windows.
They use ALRT & DLOG resources, including DITL resources to
create alert boxes, and dialogue boxes.  The program is
identified to the user with an ICN# resource.

***

All Mac files have two parts: a "data fork", which contains data
whose format is determined by the application, and a resource
fork, which contains stuff whose format is determined by the
Mac OS. It can also contain special resources whose format is
determined by the application as well.

The resource for can be viewed as a tree-structured collection
of data. This includes things like CODE (executable programs),
WDEFs (window definitions), CDEFs (control definitions), FONTs,
and so on.

***

Every Macintosh file has a "Data fork" and a "Resource Fork".
The data fork is just like a unix file, a sequence of characters.
The resource fork is a random access data base.  Each resource
is identified by a 32 bit type and a 32 bit id number.  The
resource itself contains an arbitrary piece of data.  For example
a character string.  Many resource types have a special meaning.
For example a 'FONT' resource contains a font.  Most aspects of
the Mac user interface are defined in resources, that can be
edited with ResEdit.  For example, fonts, menus, window
definitions, controls, dialogue icons and lots more.

Several resource files can be open at the same time.  When a
program requests a resource it is found by searching all open
resource files.  The order is normally

(1) The current document's resource file.
(2) The current application's resource file.  (fork).
(3) The system's resource fork. (File).

Hence a resource in the system file is always available, unless
another resource of the same type and id number is stored in the
application or document.

***

Resources are a form of virtual memory understood well enough
by most programmers for it to be successful, but misunderstood
enough to convince analysts and MIS managers that the Mac
doesn't have any ability to do the things virtual memory OS's can
do.  Every Mac file can have a data fork and a resource fork.  A
resource fork is just like a data fork except that part of it
(called the resource map) is meant to be handled only by the
resource manager (part of the OS).  Also, programmer is
supposed to only use the resource manager rather than the file
manager to access the resource fork of a file.  You use the File
Manager to access the data fork of a file.

Resources are almost everything on the Macintosh except the
data found in in your data files (documents).  Resources range
>From being executable code, templates for data structures or
data for other things like strings.  Executable code is actually
split up into two or more CODE resources called "segments".
Things like code for window definitions (WDEF) are also code
resources but aren't called CODE because they're just a bunch of
procedures.  There's only one set of procedures for all
applications to use for drawing a window, it's title bar, close
box and zoom box for all the "standard" window types because
your System file has a standard WDEF resource.  Applications
that want to use funny windows or people who want to write
INITs that make Mac windows look like NeXT windows can
simply patch the standard WDEF resource.  Some resources
describe data structures and initial values for those structures,
as in the case of DLOGs (dialog box window template) and DITLs
(dialog item lists - buttons and their locations etc).  STR
resources are an easy way to store strings that you use

often, and since they're resources, a French version of your
program could be made simply by modifying the string resources
and without recompiling your application.  Resources can be
purged from memory (by the Memory Manager) when they're not
being used.  Other resources are PICT (MacDraw picture
definitions), ICON and MBAR (menu bar defs). System resources
are shareable transparently when you use the resource
manager - when you ask for ICON ID=128 and if your app doesn't
have it, your app gets back the generic ID=128 ICON resource
>From the System.

Resources are what let 128K Macs run 300K applications that
were more impressive in their day compared to IBM PCs.  I'd
assert that most programmers today don't know how to
effectively use 1 MB of memory, our current standard, which is
about to change again.


------------------------------------------------------
MPW / Development Environments / Programming Languages
------------------------------------------------------

MPW stands for Macintosh Programmer's Workshop.  It is a very
expensive, but highly powerful and expandable development
environment for Macintosh programming.

You would be much better off to save yourself several hundred
dollars and start with THINK C, or THINK Pascal.  These two
products are incredible, similar to  Borland's Turbo products in
Clone land.  The THINK Products are very high quality, reliable,
cheap, and very (*** VERY ***) well supported. They also have
the advantage of being very small, and about 20-100 times
faster than MPW.  They will also do everything that MPW will do.

***

MPW stands for Macintosh Programming Workbench (I think).  It
is sort of a unix like shell that integrates various programming
tools.  There are many different compilers that run under MPW
and let you link code from different languages together into a
single program.  I have never used it, since I use Think C for
programming.

***

MPW stands for Macintosh Programming Workshop, and it's a
"shell" and text editor.  It runs things called "Tools", and people
like to pretend MPW is a form of a Unix shell for the Macintosh.
Several useful tools include compilers like MPW Pascal, MPW C
and CFront (Apple's C++ preprocessor).  MPW Shell lets you edit
text files usually for compilers, but not always.  It permits
aliasing, it has a form of "grep", and other things you'd normally
find in the Unix environment (Yuk).  I'd hate MPW to death if it
weren't for an OOP (Object Oriented Programming) tool like
MacApp that only works with MPW Pascal.

You will find everything unnerving and difficult until you learn
the power of true OOP languages and things like MacApp, which I
strongly recommend you learn as part of your Macintosh learning
process.  Once you've started, I suggest you immediately
consider an OOP language and an OOP tool like MacApp.  You may
think it's too soon to start thinking about that, but I have a
suspicion that by the time you are adept with the Macintosh,
everyone else will be using OOP tools. Don't let anybody convince
you otherwise.  Apple is using C++ with MacApp for their System
7.0 software, and some of the most powerful software packages
are now being written using MacApp.  Consider learning
Symantec's THINK C Class Library or MacApp as part of your
initiation to Macintosh programming.  Most adept Mac hackers
would shun such a thought, but you won't be able to survive a
year from now given the order-of-magnitude increase in turn
around time garnered from using OOP languages and tools.

MacApp comes with several apps (written in MacApp of course!)
that allow you to edit View resources (more complicated than
what ResEdit can handle) and browse C++ or Object Pascal
source code in a SmallTalk sort of fashion.  APDA sells MPW,
Pascal, C++ and MacApp.

***

Pascal and C are the languages of choice on the Mac. The
operating system was written in Pascal so much of the
documentation from Apple is in Pascal but there's usually
straightforward conversions. System 7.0 will be written in C it
is rumored so that will become even more important. MPW is the
Macintosh Programmer's Workshop from APDA, the Apple
Programmers and Developers Association. It costs about $300
for the basic shell and about $300 for each language
additionally. I use Think C from Symantec which retails for
about $120, highly recommended.


------------------------
RESEDIT
------------------------

One note I would like to make concerning the info I received
about ResEdit:  Everyone suggested that ResEdit is available
>From the archives, but I have not been able to find it listed.
Here is what people had to say about ResEdit...

Resources are usually created with Rez, or ResEdit, and stored
in the resource fork of the application's file.  They can be
created on the fly by the program, however.

*Warning*:  ResEdit will edit any resource, including those that
the Macintosh Operating System relies on.  Use at your own risk,
or face the Bomb!

***

ResEdit is a resource editor which can be used to look at and
modify things found in the resource fork. It's most often used
for things like messing with icons and suchlike.

***

ResEdit is for editing Resources.  It was
written by Apple and probably is available from APDA.  It may be
available for free, look in the info-mac archives.  It also comes
with Think C which is how I got it.

***

APDA is Apple's development tools distribution channel.  They
sell ResEdit, but I think Apple also has it for free via FTP to
Apple's FTP-able Internet workstation.  If you were at CMU, you
could get it from one of our AppleShare servers - ask around for
a copy, it's "free".

***

Resedit is "the" resource editor, and is available from APDA,
Aplle Computer, Inc., 20525 Mariani Avenue, M/S 33G, Cupertino,
CA  95014-6299.  It's $25.


--------------------------------------
READING LIST
--------------------------------------

Here are some suggestions for reading material gleaned from
the messages I received (these are not in any particular order).
The reason for this is just about everyone suggested I begin my
reading with different books, so I leave the choices up to you.

a) There was a fairly nice article in the JUNE 1989 issue of
   MACUSER on page 153 (I neglected to look at the title when I
   checked the issue).  It was on using ResEdit to modify your
   desktop (the spacing between icons and the way they are
   arranged, for instance) which was written at a nice tutorial
   level and along-the-way explained some things about ResEdit,
   certain kinds of resources, data forks, and the like.  If you
   don't get a better option, you might give it a look.

b) Read Inside Mac, Vol 1, 2, 4, & 5. (just 1 & 2 to start. 4 for
   Hierarchical File System, List Manager, & 5 for Script
   Manager, New textEdit, and color support.)

c) read Scott Knaster's "How to Write Macintosh Software."

d) Subscribe to Mactutor, but don't believe everything you need.

e) read the Tech. Notes, available by downloading or from APDA.
   These, along with examples of code are readily available
   from these archives.

f) Join APDA, the Apple Programmers & Developers Association.
   Their catalog includes tools and prerelease software
   available nowhere else. They are $20 a year, and reachable
   through Apple's Cupertino number.

g) Macintosh Revealed (all three volumes).

h) Try one of the Microsoft Press books.

i) If you just want to program and have a good time, then most
   of the reputable compilers come with decent examples that
   are worth studying. That, and the volume of Inside Mac that
   has the managers you are interested in learning, (such as Vol
   1: Quickdraw) are enough to take you a long way.

j) Pick up a copy of Kurt Schmucker's "Introduction to Object
   Oriented Programming on the Macintosh" which describes OOP
   and the old version of MacApp.

k) A book on C programming for the Macintosh which has a
   fantastic chapter on resources is from Addison-Wesley
   Publishing, Scott Knaster, Macintosh Programming primer in
   C. It  has some excellent example programs, easy to follow
   and extensible, and a logical organization.

l) "Using the Macintosh Toolbox" w/C by Takatsuka, Huxham, & Burnard.

------------------------------------
THE PANEL OF EXPERTS
------------------------------------

These are the folks who were so helpful to me.  I'm sure that if
you ask them nicely they may just be able to furnish more
specific information if you needed it!


JELLIS@BOWDOIN (Until 5/90)
David Phillip Oster (Arpa: [e-mail])
Joe McMahon <XRJDM@SCFVM>
[e-mail]
Brian Patrick Arnold <[e-mail]>
Jeff Meredith <[e-mail]>
MARGARET GIBBS ([e-mail])

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      __        |          BITNET: kesler@ouaccvma            |
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      "The above information is not mine, I have only edited the
       info I was sent to make it a bit more coherent and presentable.
       Many, many thanks to those who contributed."