TweetFollow Us on Twitter

Compiler Knows Rebuttal
Volume Number:8
Issue Number:6
Column Tag:Article Rebuttal

A Rebuttal to "The Computer Knows" Article

By Tim Swihart, Co-Author "Programming for System 7"

Just a couple of notes on the August issue (which arrived in my mailbox this weekend, so hopefully not too many other have yet mentioned some of this stuff).

• First off, great issue, v2.0 looks better with each new issue. Gar's column was great tounge-in-cheek fun!

• Secondly, a quick rebuttal to a portion of one of the articles in the August '92 issue. The problem is in John Love's “The Compiler Knows” article. The problem is on page 30, left hand column. John hard codes the menu ID for the item he appended to the help menu (#define myItem 3). That's very bad! Inside Mac, Volume VI, page 11-63 says, "In the future, Apple may choose to add other items to the Help menu. To determine the number of items in the Help menu, call the CountMItems function, which is described in the Menu Manager chapter of Volume 1."

In English, that translates to, "Don't hard code the ID of the item you append to the Help menu because the actual ID will change if Apple ever adds items to, or removes items from, the Help menu. Instead, let the toolbox tell you what ID was assigned to your item - since your item will always be at the end of the menu, CountMItems gives you the ID of the appended item."

This is a simple example of why existing applications break when new operating system features are added. In this case, doing it right is simple, so there's no reason to not do it right.

Also, John's code doesn't show what to do if your app added multiple items in the Help menu. How do you figure out which is which? "Programming for System 7" (Gary Little and Tim Swihart, Addison Wesley) shows how to handle it cleanly in Listing 8-5 (page 289). To paraphrase that approach (error checking and type declarations have been removed to simplify this explanation):

/* 1 */

HMGetHelpMenuHandle(&myHelpMenuHndl);
    bottomHelpItem = CountMItems(myHelpMenuHndl);
    secondHelpItem = bottomHelpItem - 1;
    thirdHelpItem = bottomHelpItem - 2;
    if (pickedItem == bottomHelpItem) {
        // code to do what you want when last item picked
    } else {
        if (pickedItem == secondHelpItem) {
 

         // code to execute when second to last item picked
        } else {
            if (pickedItem == thirdHelpItem) {
                // code for third to last item being picked
            }
        }
    }

One last point to make while on the subject of the Help menu. There are third-party inits available that remove the Help menu (freeing up that tiny bit of menubar space it occupies). But, some of them can have unexpected side effects on applications that assume they'll have a Help Menu since the Help Manager is present (which normally seems like a relatively valid assumption). Checking for errors returned by HMGetHelpMenuHandle() isn't enough. You'll also need to verify that the returned handle isn't nil if you want truly bulletproof code. Here's how I handle this in "BNDL Banger Pro":

/* 2 */

/* The following routine is responsible for appending  */
/* application-specific help items to the 'Help' menu. */
/* It's called from "Initialize()", just before        */       
/* "DrawMenuBar()" is called.                          */
void DoAddHMItems(void)
{
   MenuHandle  myHelpMenuHndl;
   OSErr   myErr;

   myErr = HMGetHelpMenuHandle(&myHelpMenuHndl);
   if ((!myErr) && (myHelpMenuHndl != nil)) {
 // check for nil in case some has removed the help menu 
     // (stop snickering,  I'm serious - there are such 
     // hacks readily available now )
   AppendMenu(myHelpMenuHndl,
   (ConstStr255Param)"\pBNDL Banger Pro Instructions");
   }
}

• Shifting gears considerably, I'd like to offer one last suggestion. Include the phone number for the MouseHole BBS in the MouseHole report section. [Right now, the Mousehole is on hiatus. Larry Nedry is the middle of a move to Texas. So for now, we can’t be of help here. - Ed.]

Thanks for listening.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

How to get started with live.ly
One could be forgiven for thinking that there are already plenty of streaming video apps out there. It's just that the App Store charts would insist that you're mistaken. [Read more] | Read more »
Rodeo Stampede: Guide to all Savannah an...
A "gotta catch 'em all" joke seems appropriate here, even though we're talking animals in Rodeo Stampede and not pocket monsters. By now you've probably had plenty of rides, tamed some animals and built yourself a pretty nice zoo | Read more »
Is there cross-platform play in slither....
So you've sunken plenty of hours into crawling around in slither.io on your iPhone or iPad. You've got your stories of tragedy and triumph, the times you coiled four snakes at one time balanced out by the others when you had a length of more than... | Read more »
Rodeo Stampede guide to running a better...
In Rodeo Stampede, honing your skills so you can jump from animal to animal and outrun the herd as long as possible is only half the fun. Once you've tamed a few animals, you can bring them home with you. [Read more] | Read more »
VoxSyn (Music)
VoxSyn 1.0 Device: iOS Universal Category: Music Price: $6.99, Version: 1.0 (iTunes) Description: VoxSyn turns your voice into the most flexible vocal sound generator ever. Instantly following even subtle modulations of pitch and... | Read more »
Catch Battleplans on Google Play from Ju...
Real-time strategy title Battleplans is due for release on Google Play on June 30th, following its release for iOS systems last month. With its simple interface and pretty graphics, the crowd-pleaser brings a formerly overlooked genre out for the... | Read more »
iDoyle: The interactive Adventures of Sh...
iDoyle: The interactive Adventures of Sherlock Holmes - A Scandal in Bohemia 1.0 Device: iOS Universal Category: Books Price: $1.99, Version: 1.0 (iTunes) Description: Special Release Price $1.99 (Normally $3.99) | Read more »
Five popular free apps to help you slim...
Thanks to retail and advertising, we're used to thinking one season ahead. Here we are just a week into the summer and we're conditioned to start thinking about the fall. [Read more] | Read more »
How to ride longer and tame more animals...
It's hard to accurately describe Rodeo Stampede to people who haven't seen it yet. It's like if someone took Crossy Roadand Disco Zoo and put them in a blender, yet with a unique game mechanic that's still simple and fun for anyone. [Read more] | Read more »
Teeny Titans - A Teen Titans Go! Figure...
Teeny Titans - A Teen Titans Go! Figure Battling Game 1.0.0 Device: iOS Universal Category: Games Price: $3.99, Version: 1.0.0 (iTunes) Description: Teeny Titans, GO! Join Robin for a figure battling RPG of epic proportions! TEENY... | Read more »

Price Scanner via MacPrices.net

Haven App Launches New Age Of Wirless 911 Eme...
Haven from RapidSOS represents a transformation in access to emergency services from a phone call solely dependent on voice to a robust data connection for voice, text, medical/demographic data.... Read more
Cu Parachute 1.1 Retirement Success PLanning...
Tucson, Arizona based Indie developer Bradley McCarthy has announce the release of Cu (Copper) Parachute 1.1 for iPhone, iPad, and iPod touch devices — a tool with which users can continuously... Read more
Research and Markets Releases iPhone 6s Plus...
A new analysis report from Dublin-based Research and Markets observes that with the iPhone 6s Plus, Apple introduced a new rear camera module. The new device has similar structure and technology than... Read more
Apple refurbished Retina MacBook Pros availab...
Apple has Certified Refurbished 2015 13″ and 15″ Retina MacBook Pros available for up to $380 off the cost of new models. An Apple one-year warranty is included with each model, and shipping is free... Read more
Apple refurbished 11-inch MacBook Airs availa...
Apple has Certified Refurbished 11″ MacBook Airs (the latest models), available for up to $170 off the cost of new models. An Apple one-year warranty is included with each MacBook, and shipping is... Read more
Apple price trackers, updated continuously
Scan our Apple Price Trackers for the latest information on sales, bundles, and availability on systems from Apple’s authorized internet/catalog resellers. We update the trackers continuously: - 15″... Read more
12-inch 32GB and 128GB WiFi iPad Pros on sale...
B&H Photo has 12″ 32GB & 128GB WiFi iPad Pros on sale for up to $80 off MSRP, each including free shipping. B&H charges sales tax in NY only: - 12″ Space Gray 32GB WiFi iPad Pro: $749 $50... Read more
6-core Mac Pro available for $3799, save $200
B&H Photo has the 6-core 3.5GHz Mac Pro on sale for $200 off MSRP. Shipping is free, and B&H charges sales tax in NY only: - 3.5GHz 6-core Mac Pro (sku MD878LL/A): $3799.99, $200 off MSRP Read more
Apple refurbished Apple TVs available for up...
Apple has Certified Refurbished 32GB and 64GB Apple TVs available for up to $30 off the cost of new models. Apple’s standard one-year warranty is included with each model, and shipping is free: -... Read more
13-inch Retina MacBook Pros on sale for up to...
B&H Photo has 13″ Retina MacBook Pros on sale for up to $150 off MSRP. Shipping is free, and B&H charges NY tax only: - 13″ 2.7GHz/128GB Retina MacBook Pro: $1179 $120 off MSRP - 13″ 2.7GHz/... Read more

Jobs Board

*Apple* iPhone 6s and New Products Tester Ne...
…we therefore look forward to put out products to quality test for durability. Apple leads the digital music revolution with its iPods and iTunes online store, Read more
*Apple* iPhone 6s and New Products Tester Ne...
…we therefore look forward to put out products to quality test for durability. Apple leads the digital music revolution with its iPods and iTunes online store, Read more
*Apple* iPhone 6s and New Products Tester Ne...
…we therefore look forward to put out products to quality test for durability. Apple leads the digital music revolution with its iPods and iTunes online store, Read more
*Apple* Retail - Multiple Positions, Towson...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* iPhone 6s and New Products Tester Ne...
…we therefore look forward to put out products to quality test for durability. Apple leads the digital music revolution with its iPods and iTunes online store, Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.