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From: lsr@apple.UUCP (Larry Rosenstein)
Newsgroups: net.micro.mac
Subject: Re: MacApp Paint
Message-ID: <145@apple.UUCP>
Date: Tue, 26-Aug-86 12:38:41 EDT
Article-I.D.: apple.145
Posted: Tue Aug 26 12:38:41 1986
Date-Received: Wed, 27-Aug-86 10:26:13 EDT
References: <183@ci-dandelion.UUCP>
Reply-To: lsr@apple.UUCP (Larry Rosenstein)
Distribution: net
Organization: Advanced Development Group, Apple Computer
Lines: 36

In article <183@ci-dandelion.UUCP> congdon@ci-dandelion.UUCP (Robert M. Congdon) writes:
>
>Now I wonder: was this program was written completely using MacApp 
>and Object Pascal? Also, during the demo Kurt showed a debugger that 
>allowed one to trace message sends and set breakpoints on message 
>sends. Is this a standard part of MacApp or is it part of MPW Pascal?
>

MacApp Paint was written using MacApp and Object Pascal, with a small amount
of assembler (bit manipulation stuff), most of which was copied directly
from the sources to MacPaint.  All of the user interface to the program was
written in Object Pascal.  The only non-standard thing I did was with the
scrolling (since I have the entire bitmap in memory, there is no reason to
use ScrollRect).  This was very easy to override in MacApp.

The program was was intended to demonstrate that programs written using
object-oriented programming and MacApp do not necessarily have to be slow.  

The debug window and tracing facility that were shown in the talk are a
standard part of MacApp.  (The debugging facilities in MacApp include about
70K of code.)  They are based on a feature of MPW Pascal where the compiler
can insert a procedure call at the beginning and end of each procedure.  The
MacApp debugger implements these procedures and does things such as searching
for the procedure name, etc.  (There is no technical reason why the debugger
couldn't be used in a non-MacApp program, but there is not enough time to
document it for the first MPW release.)

-- 
Larry Rosenstein

Object Specialist
Apple Computer

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