Developer CD Series 1993…ch: Other People's Memory/ADC Developer CD (1993-03) (''Other People's Memory'')_iso/Dev.CD Mar 93.iso/Development Platforms/CSMP Digests/csmp-v1-208.txt

Text File | 1992-11-18 | 33.8 KB | 1,050 lines | [TEXT/MPS ]

C.S.M.P. Digest             Wed, 04 Nov 92       Volume 1 : Issue 208

Today's Topics:

    DogCow Calls
    DYLAN
    Animated Cursors...
    Q: Stack munging in VBL tasks?
    WDEF's and QuickDraw globals
    How do I draw icl8's?
    JPartialResources.{c,h}



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-------------------------------------------------------

From: [e-mail] (Karl Pottie)
Subject: DogCow Calls
Date: 29 Sep 92 14:14:57 GMT
Organization: K.U.Leuven - Academic Computing Center


Moof !

As a true dogcow fan , I'd like to know what the toolbox calls
enable/disableDogCow() do? On which systems are they available ?

Karl

+++++++++++++++++++++++++++

From: [e-mail] (Tim Hammett)
Date: 29 Sep 92 22:03:35 GMT
Organization: University of Auckland, New Zealand.

[e-mail] (Karl Pottie) writes:
>As a true dogcow fan , I'd like to know what the toolbox calls
>enable/disableDogCow() do? On which systems are they available ?

I think you'll find they're just aliases to the _Unimplemented trap,
so they'll do whatever that trap does(probably nothing interesting).
>From the MPW Traps.h file:

#define _Unimplemented                 0xA89F
#define _InitDogCow                    0xA89F
#define _EnableDogCow                  0xA89F
#define _DisableDogCow                 0xA89F
#define _Moof                          0xA89F

(Incidentally, I couldn't find any of the DogCow traps in any of the
AIncludes files, a serious omission IMHO :-))

- --
Tim Hammett, Botany Dept, Auckland University, New Zealand.
[e-mail]   Phone: [phone] x8365    FAX: [phone]

---------------------------

From: [e-mail] (Jim Freeze)
Subject: DYLAN
Date: 17 Sep 92 15:41:07 GMT
Organization: Brigham Young University, Provo UT USA



Has anyone heard of Apple's new OO language, DYLAN?

It stands for DYnamic LANguage.

If you have heard of it, I am trying to find out if is
is available (i.e. can I get a compiler for it).
and how much and where?

Thanks for any info

Jim

+++++++++++++++++++++++++++

From: [e-mail] (Stephen C. Gilardi)
Date: 17 Sep 92 23:07:44 GMT
Organization: SQ Software via The World Public Access UNIX, Brookline, MA

[e-mail] (Jim Freeze) writes:

>Has anyone heard of Apple's new OO language, DYLAN?

>It stands for DYnamic LANguage.

>If you have heard of it, I am trying to find out if is
>is available (i.e. can I get a compiler for it).
>and how much and where?

>Thanks for any info

>Jim

There's some discussion of it over in comp.lang.scheme from time to time.
The only publicly available implementation of a Dylan-ish language that
I know of is called Thomas.  It is written in Scheme and is available by
anonymous ftp from either "crl.dec.com" or "ftp.crl.dec.com" (I don't
remember which).  The following is from the README:

Comments, questions, suggestions, help, etc. should be directed to:
          [e-mail]
Requests to be added to this mailing list should be sent to:
          [e-mail]

It runs under Gambit Scheme for example on the Mac.

Good Luck!

- --Steve
[e-mail]

+++++++++++++++++++++++++++

From: [e-mail] (Kent Sandvik)
Date: 18 Sep 92 17:33:38 GMT
Organization: Apple

In article <t!#@byu.edu>, [e-mail] (Jim Freeze) wrote:
 Has anyone heard of Apple's new OO language, DYLAN?
>
> It stands for DYnamic LANguage.
>
> If you have heard of it, I am trying to find out if is
> is available (i.e. can I get a compiler for it).
> and how much and where?

People are working on reference versions, I actually saw that
DEC posted the first one, called Thomas :-). It's available
from ftp: crl.dec.com:pub/DEC/Thomas. Works on top of various
PD Scheme systems, not fast, but it's more for testing out the
language concepts.

Kent Sandvik
who thinks it's time to get out a decent language to developers out there.

"You should really just relax" -MST3K
- -------------------
Kent Sandvik (UUCP: ....!apple!ksand; INTERNET: [e-mail])
DISCLAIMER: Private activities on the Net.

+++++++++++++++++++++++++++

From: [e-mail] (Rainer Joswig)
Date: 23 Sep 92 16:39:38 GMT
Organization: University of Hamburg, FRG

In article <t!#@byu.edu>, [e-mail] (Jim Freeze) wrote:
>
>
>
> Has anyone heard of Apple's new OO language, DYLAN?

You can find Information about Dylan in the
directory /pub/dylan on the ftp server cambridge.apple.com .
There is also the first Dylan implementation named Thomas.
In this directory you will find an faq list about Dylan.
There you can read about the new mailing list info-dylan.
Sometime near there should be a newsgroup comp.lang.dylan .

Rainer Joswig
Email: [e-mail]

---------------------------

From: [e-mail] (Peter Wayner)
Subject: Animated Cursors...
Date: 17 Sep 92 22:48:34 GMT
Organization: Express Access Online Communications, Greenbelt, MD USA

Can anyone point me toward the right way
to install an animated cursor?

Thanks,

Peter Wayner
([e-mail])

+++++++++++++++++++++++++++

From: [e-mail] (Chuck Hoffman)
Date: 18 Sep 92 14:07:27 GMT
Organization: GTE Laboratories

In article <[e-mail]>, [e-mail]
(Peter Wayner) wrote:
>
> Can anyone point me toward the right way
> to install an animated cursor?
>

Create the several cursor resources you need which will make up your
animation.  Then create an 'acur' resource which is a list of the cursor
id's.  Then somewhere in your program get the 'acur' resource, then use
SetCursor from time to time to switch from one cursor id to the next, as
listed in the 'acur'.

Someone advised recently that it could also be done through the vertical
retrace manager, but someone else pointed out that this would hide from the
user the effect of speeding up and slowing down which the calls from within
the program code would reveal.

Chuck Hoffman
[e-mail]
GTE Laboratories, Waltham, Massachusetts, USA
[phone]
=====================================
I'm not sure why we're here, but I am sure that while we're here we're
supposed to help each other.
=====================================

+++++++++++++++++++++++++++

From: [e-mail] (Jamie R. McCarthy)
Date: 24 Sep 92 01:08:27 GMT
Organization: Kalamazoo College

[e-mail] (Adam Winer) writes:
>[e-mail] (Matt Mora) writes:
>>[e-mail] (Chuck Hoffman) writes:
>>>
>>>[You can do cursor animation from inside a VBL task]
>>
>>The key is to have the vbl task check a counter that the program increments.
>>The vbl would then show the true performance. And on the occasion that
>>the program gets stuck in an endless loop, the vbl could detect that
>>and either trigger a fail routine or jump to it.
>
>This strikes me as overkill: if the vbl task is going to refer back to
>a program counter, just change the cursor from within the normal flow
>of your program.

Agreed, Adam.

Additionally, Matt, I'm not sure if it would even be remotely possible
for a VBL task to break a program out of its endless loop.  You
certainly don't want to jump straight to the fail routine;  you're still
servicing the interrupt.  The only way that I can see is to find the PC
from wherever the interrupt code hid it, check to be sure it's in your
heap, and modify the code about to be executed by writing a "JMP fail"
over it.  Don't forget to save the original instructions somewhere so
you can restore them, and to flush the instruction cache.  :-/

I'm sure there are ickier ways to crash-proof a program than using a
periodic interrupt to save you from infinite loops, but at the moment
I can't think of any...
- --
 Jamie McCarthy      Internet: [e-mail]      AppleLink: j.mccarthy
 "I don't think we should have to have them wandering the streets
  frightening women and people."                            - Pat Buchanan

+++++++++++++++++++++++++++

From: [e-mail] (Matthias Urlichs)
Date: 30 Sep 92 00:57:07 GMT
Organization: University of Karlsruhe, FRG

In comp.sys.mac.programmer, article <[e-mail]>,
  [e-mail] (Matt Mora) writes:
>
> The key is to have the vbl task check a counter that the program increments.
> The vbl would then show the true performance. And on the occasion that
> the program gets stuck in an endless loop, the vbl could detect that
> and either trigger a fail routine or jump to it.
>
I don't think that jumping out of a VBL or quitting an application from
under it would be that good an idea. Memory may be in an inconsistent state,
the interrupt level is not zero, and the VBL queue is marked busy. Undoing
all of this manually is a big compatibility risk.

If your application hangs, it's a bug. I respectfully suggest that you debug
your applications before shipping them to customers.  ;-)

- --
Bradley's Bromide:
        If computers get too powerful, we can organize them into a
        committee -- that will do them in.
- --
Matthias Urlichs  --  [e-mail] -- [e-mail]   /(o\
Humboldtstrasse 7 -- 7500 Karlsruhe 1 -- Germany  --  [phone]     \o)/

---------------------------

From: [e-mail] (Daniel McCabe)
Subject: Q: Stack munging in VBL tasks?
Date: 22 Sep 92 16:48:07 GMT


Is there a kosher way of finding out what the stack pointer was immediately
prior to the VBL interrupt? I want to write some code which performs a
task switch in a VBL task, but to do that, I need to know where the SP
was prior to the VBL interrupt. I haven't found this info in either
IM or in Tech Notes. If I missed it, any pointers are appreciated.

Thanx in advance,
danm

+++++++++++++++++++++++++++

From: [e-mail] (Keith Rollin)
Date: 23 Sep 92 19:42:44 GMT
Organization: Taligent

In article <[e-mail]>, [e-mail] (Daniel
McCabe) wrote:
>
> Is there a kosher way of finding out what the stack pointer was immediately
> prior to the VBL interrupt? I want to write some code which performs a
> task switch in a VBL task, but to do that, I need to know where the SP
> was prior to the VBL interrupt. I haven't found this info in either
> IM or in Tech Notes. If I missed it, any pointers are appreciated.
>

MPW Shell does something like this. The details are sketchy, but I think I
have the right idea. MPW Shell installs a VBL task and then goes into a
tight loop:

        TightLoop     bra.s TightLoop

When it gets triggered 1/60 of a second later, the VBL task then looks for
the address of TightLoop on the stack. From that information, it determines
what you are asking for.

Why does MPW do this? I believe it's so you can press Cmd-Period to break
out of hung tools (it also installs a VBL to look for Cmd-Period).

- -----
Keith Rollin
Phantom Programmer
Taligent, Inc.

+++++++++++++++++++++++++++

From: [e-mail] (Phil Shapiro)
Organization: Symantec Corp.
Date: Fri, 25 Sep 1992 15:10:16 GMT

>>>>> On Wed, 23 Sep 1992 19:42:44 GMT, [e-mail] (Keith Rollin) said:

 > Why does MPW do this? I believe it's so you can press Cmd-Period to
 > break out of hung tools (it also installs a VBL to look for
 > Cmd-Period).

Hmm, last time I checked MPW installs a handler in the low memory auto
interrupt vector; kind of an odd way to check for command-period if
you ask me. I suppose this would enable MPW to remove all VBLs
belonging to the stopped tool, though...

    -phil
- --
   Phil Shapiro                                   Software Engineer
   Language Products Group                     Symantec Corporation
           Internet: [e-mail]

---------------------------

From: [e-mail] (William Conrad Wojciechowski)
Subject: WDEF's and QuickDraw globals
Date: 30 Sep 92 09:03:43 GMT
Organization: H&SS Dean's Office, Carnegie Mellon, Pittsburgh, PA

I was wondering if anybody has a reliable solution for accessing
QuickDraw globals in a WDEF.  Right now, I am creating patterns and
other needed globals on the fly.  This is a safe method but, I would
like to know if there is a safe way to directly access the QuickDraw
globals.

Thanks in advance.

- - Will

+++++++++++++++++++++++++++

From: [e-mail] (Keith Rollin)
Organization: Taligent
Date: Wed, 30 Sep 1992 20:53:04 GMT

In article <[e-mail]>, [e-mail]
(William Conrad Wojciechowski) wrote:
>
> I was wondering if anybody has a reliable solution for accessing
> QuickDraw globals in a WDEF.  Right now, I am creating patterns and
> other needed globals on the fly.  This is a safe method but, I would
> like to know if there is a safe way to directly access the QuickDraw
> globals.

I usually use routines like the following:

typedef struct {
    char        privates[76];
    long        randSeed;
    BitMap        screenBits;
    Cursor        arrow;
    Pattern        dkGray;
    Pattern        ltGray;
    Pattern        gray;
    Pattern        black;
    Pattern        white;
    GrafPtr        thePort;
} QDGlobals;

long*    GetA5(void) = 0x200D;            // move.l    A5,D0

Pattern*    GetWhitePattern()
{
    long*        curA5;
    curA5 = GetA5();
    return (Pattern*) (*curA5 - (sizeof(QDGlobals) - sizeof(Ptr)) +
                    offsetof(QDGlobals, white));
}

- -----
Keith Rollin
Phantom Programmer
Taligent, Inc.

---------------------------

From: [e-mail] (Sho Kuwamoto)
Subject: How do I draw icl8's?
Date: 30 Sep 92 18:40:13 GMT
Organization: Purdue University Physics Department

IM VI gives the following useful info:
    [PlotIcon and PlotCIcon] will not draw any icons that
    are defined by the icon resources new to system
    software 7.0 -- namely, the 'ics#', 'icl4', 'ics4',
    'icl8', and 'ics8' resources.

Unfortunately, IM VI does not seem to say how one goes about
drawing these icons.  Well, how *do* I draw these types of
icons?  Also, is there an easy way for me to hilight the
icons in the same way that the Finder does?

- -Sho
- --
[e-mail]

+++++++++++++++++++++++++++

From: [e-mail] (Narayan R. Sainaney)
Organization: University of British Columbia, Vancouver, B.C., Canada
Date: Thu, 1 Oct 1992 00:24:40 GMT

In article <[e-mail]> [e-mail] (Sho Kuwamoto) writes:
>IM VI gives the following useful info:
>    [PlotIcon and PlotCIcon] will not draw any icons that
>    are defined by the icon resources new to system
>    software 7.0 -- namely, the 'ics#', 'icl4', 'ics4',
>    'icl8', and 'ics8' resources.
>
>Unfortunately, IM VI does not seem to say how one goes about
>drawing these icons.  Well, how *do* I draw these types of
>icons?  Also, is there an easy way for me to hilight the
>icons in the same way that the Finder does?
>
>-Sho
>--
>[e-mail]

    You are in luck. I just finised working on Luanch Pad (a
shareware app) that makes extensive use of PlotIconID which is very
well documented in APDA tech Note 306. The routine call is:

err:= PlotIconID (theRect,align,transform,theResID)

where align and transform allow you to do neat stuff like center/
left or right justify it and transfor it (launched etc etc)

The interface file is at the end of the tech note and it contains
all the values possible for align and transform (integers). The inline
function is:

function PlotIconID(theRect:Rect;align:Integer;transform:integer;
                    theResID:Integer):OsErr;
inline
 $303C,$0500,$ABC9

hope this helps.
[e-mail]
PS: To do a simple plot, use 0,0 for align and transform.


---------------------------

From: [e-mail] (Jamie R. McCarthy)
Subject: JPartialResources.{c,h}
Date: 24 Sep 92 23:24:23 GMT
Organization: Kalamazoo College

Following is my current working version of "Jamie's Partial Resources,"
glue that makes the system-7 partial resource calls work under any
system.  I'm posting this here 'cause I haven't seen partial-resource
glue anywhere else, and I thought it might be useful.

Please note that this is not a final copy--jSetResourceSize() doesn't do
anything, jWritePartialResource() has never been tested, and
jReadPartialResource() has been extensively tested for all of forty-five
minutes.  They're working fine for me so far, though (and if there were
anything seriously wrong, I'm sure the crashes would be spectacular).
If and when I get it working more solidly, I'll post the code here.
(Don't expect jSetResourceSize() though--an efficient implementation is
far harder for that function than for the other two, and I don't need
it yet, so it's way down low on my priority list.)

Usage is simple:  whenever you might call ReadPartialResource or
WritePartialResource, call jReadPartialResource or jWritePartialResource
instead.  To get the resource handle to pass to them, SetResLoad(FALSE)
and GetResource(type, id).  (Oh, and SetResLoad(TRUE) again, of course.)
- --
 Jamie McCarthy      Internet: [e-mail]      AppleLink: j.mccarthy
 Was bringt mich nicht um...



/*
 * JPartialResources.h
 *
 * Jamie's partial resource calls that work under any system.
 * (c) Copyright 1992 by Jamie R. McCarthy.  All rights reserved.
 * This code can be both distributed and used freely.
 *
 */



/******************************/

extern Boolean partialResourceCallsAvailable;

/******************************/



void jReadPartialResource(Handle theResource, long offset, void *buffer, long count);
void jWritePartialResource(Handle theResource, long offset, void *buffer, long count);
void jSetResourceSize(Handle theResource, long size);





/*
 * JPartialResources.c
 *
 * Jamie's partial resource calls that work under any system.
 * (c) Copyright 1992 by Jamie R. McCarthy.  All rights reserved.
 * This code can be both distributed and used freely.
 * Internet: [e-mail]       AppleLink: j.mccarthy
 * Telephone:  [phone] or US 616-665-7075 (9:00-5:00 Eastern time)
 * I'm releasing this code with the hope that someone will get something
 * out of it.  Feedback of any sort, even just letting me know that you're
 * using it, is greatly appreciated!
 *
 *
 * "Be aware that having a copy of a resource in memory when you are using
 *  the partial resource routines may cause problems.  If you have modified
 *  the copy in memory and then access the resource on disk using either
 *  the ReadPartialResource or WritePartialResource procedure, you will
 *  lose changes made to the copy in memory."  - IM VI, 13-21
 *
 * By "copy in memory," this refers to having the entire resource loaded in.
 * What it's saying is that ReadPartialResource and WritePartialResource
 * consider themselves free to purge (and maybe reload) the resource
 * handle.  Incidentally, my routines don't do that--they read directly from
 * disk--so if you're under system 6, your copy of the resource is safe.
 * (Memory may be moved, however, so if the resource is purgeable, it may
 * be purged.)
 *
 *
 * "...there's really no reason to access resources directly."  - IM IV-16.
 *
 * Yeah right.
 *
 */



/******************************/

#include "JPartialResources.h"

/******************************/

#include <GestaltEqu.h>

/******************************/

#define kUninitializedFlag (42)
Boolean partialResourceCallsAreAvailable = kUninitializedFlag;

void determineWhetherPRCallsAreAvailable(void);

/******************************/

typedef struct {
   unsigned long     offsetToRsrcData;
   unsigned long     offsetToRsrcMap;
   unsigned long     lengthOfRsrcData;
   unsigned long     lengthOfRsrcMap;
} rsrcForkHeader;

typedef struct {
   short             rsrcID;
   short             offsetToRsrcName;
   unsigned long     rsrcAttrs : 8;
   unsigned long     offsetToRsrcData : 24;
   Handle            rsrcHndl;
} rsrcReference;

struct rsrcMap;
typedef struct rsrcMap rsrcMap, *rsrcMapPtr, **rsrcMapHndl;
struct rsrcMap {
   rsrcForkHeader    copyOfRsrcForkHeader;
   rsrcMapHndl       nextRsrcMapHndl;
   short             fileRefNum;
   short             fileAttrs;
   unsigned short    offsetToTypeList;
   unsigned short    offsetToNameList;
} ;

/******************************/

      /*
       * Lower-level internal functions.
       */

   /*
    * Just as _HomeResFile returns the refNum of a resource's file,
    * so does getHomeRsrcMap() return a pointer to the resource
    * file's map.  Warning--any calls that may move memory,
    * including system memory, invalidate the pointer!
    */
rsrcMapPtr getHomeRsrcMap(Handle theResource);

   /*
    * This uses _RsrcMapEntry and getHomeRsrcMap() to find the
    * offset from the beginning of a resource fork to the start of
    * a resource's reference.
    */
long getRsrcRefOffsetIntoFile(Handle theResource);

/******************************/

      /*
       * Higher-level internal functions.
       */

   /*
    * This uses getRsrcRefOffsetIntoFile() and FSRead() to find
    * the offset from the beginning of a resource fork to the start
    * of a resource's data.  The offset points to the data itself,
    * which is just past the longword that tells its size.  If you
    * happen to want the size too, use _SizeResource.
    */
long getRsrcDataOffsetIntoFile(Handle theResource);

long getRsrcFileMark(Handle theResource);
void setRsrcFileMark(Handle theResource, long newMark);

/******************************/



void jReadPartialResource(Handle theResource, long offset, void *buffer, long count)
{
   if (partialResourceCallsAreAvailable == kUninitializedFlag) {
      determineWhetherPRCallsAreAvailable();
   }

   if (partialResourceCallsAreAvailable) {
      ReadPartialResource(theResource, offset, buffer, count);
   } else {

      long theRsrcDataOffset;
      long theRsrcDataLength;
      OSErr theErr;
      long oldMark;

      oldMark = getRsrcFileMark(theResource);
      theRsrcDataOffset = getRsrcDataOffsetIntoFile(theResource);
      if (theRsrcDataOffset < 0) return ;
      setRsrcFileMark(theResource, theRsrcDataOffset + offset);
      theErr = FSRead( HomeResFile(theResource), &count, buffer );
      setRsrcFileMark(theResource, oldMark);

   }
}



void jWritePartialResource(Handle theResource, long offset, void *buffer, long count)
{
   if (partialResourceCallsAreAvailable == kUninitializedFlag) {
      determineWhetherPRCallsAreAvailable();
   }

      /*
       * Disallow writing past the end of the resource;
       * try to increase its size if possible.
       */
   if (SizeResource(theResource) < offset+count) {
      jSetResourceSize(theResource, offset+count);
   }

      /*
       * Check to be sure the size was successfully increased
       * before continuing.
       */
   if (SizeResource(theResource) < offset+count) {
      return ;
   }

   if (partialResourceCallsAreAvailable) {
      WritePartialResource(theResource, offset, buffer, count);
   } else {

      long theRsrcDataOffset;
      OSErr theErr;
      long oldMark;

      oldMark = getRsrcFileMark(theResource);
      theRsrcDataOffset = getRsrcDataOffsetIntoFile(theResource);
      if (theRsrcDataOffset < 0) return;
      setRsrcFileMark(theResource, theRsrcDataOffset + offset);
      theErr = FSWrite( HomeResFile(theResource), &count, buffer );
      setRsrcFileMark(theResource, oldMark);

   }
}



void jSetResourceSize(Handle theResource, long size)
{
   if (partialResourceCallsAreAvailable == kUninitializedFlag) {
      determineWhetherPRCallsAreAvailable();
   }

   if (partialResourceCallsAreAvailable) {
      SetResourceSize(theResource, size);
   } else {

      Debugger();

   }
}



void determineWhetherPRCallsAreAvailable(void)
{
   if (partialResourceCallsAreAvailable == kUninitializedFlag) {
      OSErr theOSErr;
      long theResponse;
      partialResourceCallsAreAvailable = FALSE;
#ifdef appleHadActuallyImplementedTheResourceMgrAttrSelectorInSystem7_0_x
      theOSErr = Gestalt(gestaltResourceMgrAttr, &theResponse);
      if (theOSErr == noErr) {
         if ( (theResponse & 1L<<gestaltPartialRsrcs) != 0 ) {
            partialResourceCallsAreAvailable = TRUE;
         }
      }
#else
      theOSErr = Gestalt(gestaltSystemVersion, &theResponse);
      if (theOSErr == noErr) {
         if ( (theResponse & 0x0000FFFF) >= 0x0700 ) {
            partialResourceCallsAreAvailable = TRUE;
         }
      }
#endif
   }
}



/******************************/



rsrcMapPtr getHomeRsrcMap(Handle theResource)
{
   rsrcMapHndl cMapHndl;
   short theRefNum;

   theRefNum = HomeResFile(theResource);
   cMapHndl = (rsrcMapHndl) TopMapHndl;

   while ( (**cMapHndl).fileRefNum != theRefNum ) {
      cMapHndl = (**cMapHndl).nextRsrcMapHndl;
      if (cMapHndl == NULL) return NULL;
   }

   return *cMapHndl;
}



long getRsrcRefOffsetIntoFile(Handle theResource)
{
   long offsetToRsrcRefFromRsrcMap;
   long offsetToRsrcMapFromStartOfFile;

   rsrcMapPtr theRsrcMapPtr;

   ASSERT(theResource != NULL);

   offsetToRsrcRefFromRsrcMap = RsrcMapEntry(theResource);
   if (offsetToRsrcRefFromRsrcMap == 0) {
         /* ResError contains the error. */
      return -1;
   }

   theRsrcMapPtr = getHomeRsrcMap(theResource);
   offsetToRsrcMapFromStartOfFile = theRsrcMapPtr->copyOfRsrcForkHeader.offsetToRsrcMap;

   return offsetToRsrcMapFromStartOfFile + offsetToRsrcRefFromRsrcMap;
}



long getRsrcDataOffsetIntoFile(Handle theResource)
{
   rsrcReference theRsrcRef;
   long theOffsetToRsrcRef;
   long theOffsetToRsrcData;
   long oldMark;
   OSErr theErr;
   long nBytesToRead;

   theOffsetToRsrcRef = getRsrcRefOffsetIntoFile(theResource);

   oldMark = getRsrcFileMark(theResource);
   setRsrcFileMark(theResource, theOffsetToRsrcRef);
   nBytesToRead = sizeof(rsrcReference);
   theErr = FSRead( HomeResFile(theResource), &nBytesToRead, &theRsrcRef);
   setRsrcFileMark(theResource, oldMark);

   if (theErr != noErr || nBytesToRead < sizeof(rsrcReference)) {
      return -1;
   }

   theOffsetToRsrcData = theRsrcRef.offsetToRsrcData
      + 0x0100       // add in the length of the resource header
      + 4;           // skip over the longword that tells the resource's length
   return theOffsetToRsrcData;
}



long getRsrcFileMark(Handle theResource)
{
   OSErr theErr;
   long theMark;
   ASSERT(theResource != NULL);
   theErr = GetFPos( HomeResFile(theResource), &theMark );
   if (theErr != noErr) theMark = -1;
   return theMark;
}



void setRsrcFileMark(Handle theResource, long newMark)
{
   ASSERT(theResource != NULL);
   /* theOSErr = */ SetFPos( HomeResFile(theResource), fsFromStart, newMark );
}

+++++++++++++++++++++++++++

From: [e-mail] (Mike Gleason)
Date: Fri, 25 Sep 1992 21:15:32 GMT
Organization: NCEMRSoft

[e-mail] (Jamie R. McCarthy) writes:

>Following is my current working version of "Jamie's Partial Resources,"
>glue that makes the system-7 partial resource calls work under any
>system.  I'm posting this here 'cause I haven't seen partial-resource
>glue anywhere else, and I thought it might be useful.

> [code omitted]

This reminds me of a catch-22 when writing apps that run under 7.0 and 6.x.
You end up using the archaic 6.x routines because 6.x doesn't have the useful
7.0 stuff, and/or writing your own version of the 7.0 stuff for the 6.x users.
Prime example: the FSSpec calls in the 7.0 File Manager.  Wouldn'tcha just
love to use these?  Unless you write your own glue to use FSSpecs you have
to settle with using FSSpecs as variables, then passing fs.name, fs.vRefNum,
and fs.parID to HOpen() instead of FSpOpenDF().

I nominate that the FSSpec calls be added to a new System version 6.1.
There are probably other bits (like partial resources, even though they're
not used often) that could be added to a 6.1 that wouldn't require the rest
of the 7.0 OS.

- --
______________________________________________________________________________
mike gleason                 [e-mail]             NCEMRSoft, baby!

+++++++++++++++++++++++++++

From: [e-mail] (Jamie R. McCarthy)
Date: 25 Sep 92 22:59:52 GMT
Organization: Kalamazoo College

[e-mail] (Mike Gleason) writes:
>[e-mail] (Jamie R. McCarthy) writes:
>
>This reminds me of a catch-22 when writing apps that run under 7.0 and 6.x.
>You end up using the archaic 6.x routines because 6.x doesn't have the useful
>7.0 stuff, and/or writing your own version of the 7.0 stuff for the 6.x users.
>
>I nominate that the FSSpec calls be added to a new System version 6.1.
>There are probably other bits (like partial resources, even though they're
>not used often) that could be added to a 6.1 that wouldn't require the rest
>of the 7.0 OS.

...and then how many users would upgrade to 6.1?  We'd still end up
having to write the dual-system code for the next n years, until a
sufficiently small number of 6.0 users remained.

Ideally, Apple would release small code libraries (object code maybe?)
that would do the Right Thing for things like the new FSSpec calls under
both 7 and 6.  It'd save developers a lot of hassle, and would get
studly products to market quicker...of course, if they'd intended to do
that, they'd have done it two years ago...
- --
 Jamie McCarthy      Internet: [e-mail]      AppleLink: j.mccarthy
 I'm your only friend, I'm not your only friend, but I'm a little glowing
 friend, but really I'm not actually your friend, but I am...

+++++++++++++++++++++++++++

From: [e-mail] (Steven Dorner)
Date: 27 Sep 92 16:14:12 GMT
Organization: Qualcomm, Inc

[e-mail] (Jamie R. McCarthy) wrote:
> ...and then how many users would upgrade to 6.1?  We'd still end up
> having to write the dual-system code for the next n years, until a
> sufficiently small number of 6.0 users remained.

System 7 will be two years old this coming spring.  1M SIMM's are $25.
Enough is enough; I'm making one more system 6 compatible release, and then
I'm simply going to forget that System 6 ever existed.

+++++++++++++++++++++++++++

From: [e-mail] (Grobbins)
Date: 27 Sep 92 22:53:38 GMT
Organization: Apple Computer Inc., Cupertino, CA

In article <[e-mail]> [e-mail] (Jamie R. McCarthy) writes:
>[e-mail] (Mike Gleason) writes:
>>I nominate that the FSSpec calls be added to a new System version 6.1.
>>There are probably other bits (like partial resources, even though they're
>>not used often) that could be added to a 6.1 that wouldn't require the rest
>>of the 7.0 OS.
>Ideally, Apple would release small code libraries (object code maybe?)
>that would do the Right Thing for things like the new FSSpec calls under
>both 7 and 6.

The current interfaces do help a bit; in particular, Gestalt and
FindFolder can be used without regard to the system being run
because of the glue which is automatically supplied (at least
by the MPW and Think C and Pascal compilers.)

If your main desire is for FSSpecs, it's easy to write wrapper
functions.  Alternatively, most FSp---- and Alias Manager calls
are available under System 6.0.7 if QuickTime is installed, so that
is one way to modernize old system versions.

Grobbins             [e-mail]

Usual disclaimers apply.

+++++++++++++++++++++++++++

From: [e-mail] (Michael Peirce)
Date: 29 Sep 92 00:06:43 GMT
Organization: Peirce Software


In article <[e-mail]> (comp.sys.mac.programmer), [e-mail] (Steven Dorner) writes:
> [e-mail] (Jamie R. McCarthy) wrote:
> > ...and then how many users would upgrade to 6.1?  We'd still end up
> > having to write the dual-system code for the next n years, until a
> > sufficiently small number of 6.0 users remained.
>
> System 7 will be two years old this coming spring.  1M SIMM's are $25.
> Enough is enough; I'm making one more system 6 compatible release, and then
> I'm simply going to forget that System 6 ever existed.

My product Smoothie doesn't support System 6. It came out after System
7 had been around a while and it takes advantage of a number of System 7
features.

I've yet to have anyone complain about not supporting System 6...
(no doubt I'll get a complain about 15 minutes after I post this,
but so far so good!)

- --  Michael Peirce      --   [e-mail]
- --  Peirce Software     --   Suite 301, 719 Hibiscus Place
- --                      --   San Jose, California USA 95117
- --  Makers of...        --   voice: [phone] fax: [phone]
- --            SMOOTHIE  --   AppleLink: peirce & America Online: AFC Peirce

---------------------------

End of C.S.M.P. Digest
**********************