TweetFollow Us on Twitter

Dec 95 Tips
Volume Number:11
Issue Number:12
Column Tag:Tips & Tidbits

Tips & Tidbits

By Steve Sisak, Contributing Editor

Note: Source code files accompanying article are located on MacTech CD-ROM or source code disks.

TIP OF THE MONTH

Arguments To “s” In MacsBug

In MacsBug, the s [step] command will take an argument which is either a count or a condition on which to stop. This can be very useful for unwinding a twisty bit of code. For example, if you keep crashing in a particular spot, but you can’t tell how you got there or what happened just before, you can break before everything goes wrong and type


  s (pc == <badspot>)

Where badspot is where you know things are wrong. Macsbug will step through all of the instructions in between here and there. You can then examine the path taken in the scrollback or, if you turn on the log first, look at it all offline with an editor. With the newest versions of MacsBug, you can even step over mixed mode. Note that it’s possible for find weirder problems, too:


 s (a0 == 0)

will step until a0 equals 0.

 

 s (<addr>^ != <current value>)

will step until the long at <addr> changes.

You can use this trick to find a really wide variety of problems. Should you use this tip, donate my fee to the American Red Cross.

- Tim Dierks

They Said I Couldn’t
Return Errors From Constructors

I have read several times that “you can’t return an error from a constructor”. This is not entirely true. See the following code example:

class exampleClass : parentClass
{
  exampleClass( int arg1, OSErr& errOut );
    // initialization constructor
...etc....
};

exampleClass::exampleClass( int arg1, OSErr& errOut )
 : parentClass()  // parent class constructor explicitly called
 , memberData() // instance variable's explict constructor
{
//  errOut = noErr;  see note #4 below
  errOut = someSystemCall( arg1 );
}

void main ( void )
{
   OSErr  err;
   exampleClass  aVar( 12, err );
   if ( err != noErr ) 
   {....etc....
}

This example “obviously” returns error information.

However, errOut will NOT have a known value if the following occurs:

1. parentClass’s explicit constructor throws an exception.

2. memberData’s explicit constructor throws an exception.

3. someSystemCall throws an exception. This example used explicit contructor calls, but the same is true for implicit constructor calls to parent classes and member data varables.

4. if the errOut = noErr line is uncommented, then at least errOut can have a known value in the absence of other exceptions.

Of course, since main isn’t doing try/catch, then the test of err != noErr is not going to happen when an exception occurs, either.

- C. Keith Ray

Is Your App Windowshade Savvy?

Many apps change the cursor within certain areas of their windows. This may be to provide the crosshairs in a drawing window, or a hand cursor if something can be dragged in an area of your window. Unfortunately, many applications forget to check whether their window is windowshaded or not. If their window is windowshaded but still the front window, they go ahead and change the cursor anyway, leading to the effect of the cursor changing over “empty space.” Looks ugly. Here’s the fix:

if (EmptyRgn( ((WindowPeek)TheWindow)->contRgn )) 
//window shade has been used

Don’t change the cursor;

else

Go ahead and change the cursor;

In the above example, TheWindow is the windowptr to the window who’s areas we are changing the cursor for.

- Richard Unger and Eric Bourque

Shortcut to Open Header Files In CodeWarrior

Here is a feature that I’d long hoped for, and recently, by accident, found.

In Metrowerk’s IDE, typing ‘command tab’ will open the corresponding .h or .cp file. For example, if you’re working in a source file named “FileName.cp” typing ‘command tab’ will open “FileName.h”. This is an extremely useful feature that I hope Symantec will adopt.

- Norman Basha

Drop Into MacsBug at a Predictable Address

When dropping into MacsBug, I often find myself in the wrong application’s code. For example, lets say I want to force-quit the finder using “es” from MacsBug. (command-option-escape will quit and then restart the Finder). To make sure the Finder is the frontmost app, I hold the mouse down in one of the Finder’s menus and press the interrupt key, and I’m dropped in at a known location (a small loop within the menu manager). Not only that, but the current menu manager is emulated on PowerMacs, further ensuring my safety. Then a simple “es” quits the Finder.

- Damon Cokenias

Lock Your Libraries, Prevent Changes

Here’s a tip that may be obvious, but it’s useful, if somewhat simple.

If you don’t want to modify the standard libraries included in a development environment (the source to PowerPlant or TCL for example) you can use the following script to lock all the files. I use this script in MPW, but should work with ToolServer as well:

### First set the current directory to the folder containing the sources 
to lock
### note that this script does sub-folders also.
### replace "xxx" with your path, e.g., "HD:MPW:Interfaces:"
directory "Full path to the folder in which the files are:"

### Then set the lock bit to ON for all files which are of
### type 'TEXT' in the current directory and all sub-directories
### Notes:
###   remove "-r" to skip sub-directories
###   make the "L" lowercase ("l") to un-lock files
###   the -f is for full paths, -s to supress directory listings
SetFile -a L `files -r -f -s -t 'TEXT'`

Anyway, just thought I’d pass it on. It’s particularly useful while using a class browser like Object Master, where you can browse all classes and it’s easy to end up editing one of the supplied classes in PowerPlant/Think Class Library/MacApp.

- Tyler Morrison

[AppleScript also supports locking and unlocking of files. Simply modify the “locked” property of x, where x is a file alias or file name with: set the locked of file x to true

EdAsst - jtk]

 
AAPL
$102.08
Apple Inc.
+2.32
MSFT
$44.83
Microsoft Corpora
+0.75
GOOG
$523.95
Google Inc.
+3.11

MacTech Search:
Community Search:

Software Updates via MacUpdate

RapidWeaver 6.0 - Create template-based...
RapidWeaver is a next-generation Web design application to help you easily create professional-looking Web sites in minutes. No knowledge of complex code is required, RapidWeaver will take care of... Read more
NTFS 12.0.39 - Provides full read and wr...
Paragon NTFS breaks down the barriers between Windows and OS X. Paragon NTFS effectively solves the communication problems between the Mac system and NTFS, providing full read and write access to... Read more
RestoreMeNot 2.0.3 - Disable window rest...
RestoreMeNot provides a simple way to disable the window restoration for individual applications so that you can fine-tune this behavior to suit your needs. Please note that RestoreMeNot is designed... Read more
Macgo Blu-ray Player 2.10.9.1750 - Blu-r...
Macgo Mac Blu-ray Player can bring you the most unforgettable Blu-ray experience on your Mac. Overview Macgo Mac Blu-ray Player can satisfy just about every need you could possibly have in a Blu-ray... Read more
Apple iOS 8.1 - The latest version of Ap...
The latest version of iOS can be downloaded through iTunes. Apple iOS 8 comes with big updates to apps you use every day, like Messages and Photos. A whole new way to share content with your family.... Read more
TechTool Pro 7.0.5 - Hard drive and syst...
TechTool Pro is now 7, and this is the most advanced version of the acclaimed Macintosh troubleshooting utility created in its 20-year history. Micromat has redeveloped TechTool Pro 7 to be fully 64... Read more
PDFKey Pro 4.0.2 - Edit and print passwo...
PDFKey Pro can unlock PDF documents protected for printing and copying when you've forgotten your password. It can now also protect your PDF files with a password to prevent unauthorized access and/... Read more
Yasu 2.9.1 - System maintenance app; per...
Yasu was originally created with System Administrators who service large groups of workstations in mind, Yasu (Yet Another System Utility) was made to do a specific group of maintenance tasks... Read more
Hazel 3.3 - Create rules for organizing...
Hazel is your personal housekeeper, organizing and cleaning folders based on rules you define. Hazel can also manage your trash and uninstall your applications. Organize your files using a... Read more
Autopano Giga 3.7 - Stitch multiple imag...
Autopano Giga allows you to stitch 2, 20, or 2,000 images. Version 3.0 integrates impressive new features that will definitely make you adopt Autopano Pro or Autopano Giga: Choose between 9... Read more

Latest Forum Discussions

See All

Fiete – A Day on a Farm Review
Fiete – A Day on a Farm Review By Amy Solomon on October 21st, 2014 Our Rating: :: A MEMORABLE EXPERIENCEUniversal App - Designed for iPhone and iPad Fiete – A day on a farm in an interactive app for young children full of... | Read more »
Tilt to Live: Gauntlet’s Revenge is Almo...
Tilt to Live: Gauntlet’s Revenge is Almost Here Posted by Jessica Fisher on October 21st, 2014 [ permalink ] One Man Left has announced the official release date of Tilt to Live: Gauntlet’s Re | Read more »
Sago Mini Monsters Celebrates Halloween...
Sago Mini Monsters Celebrates Halloween with Fun Costumes and Special Treats. Posted by Jessica Fisher on October 21st, 2014 [ permal | Read more »
Inferno 2 Review
Inferno 2 Review By Andrew Fisher on October 21st, 2014 Our Rating: :: TWIN STICK GOODNESSUniversal App - Designed for iPhone and iPad With tight controls and awesome, stark visuals, Inferno 2 is loads of fun.   | Read more »
Clips Review
Clips Review By Jennifer Allen on October 21st, 2014 Our Rating: :: CONVENIENT PASTINGUniversal App - Designed for iPhone and iPad Making copying and pasting more powerful than usual, Clips is a great way to move stuff around.   | Read more »
MonSense Review
MonSense Review By Jennifer Allen on October 21st, 2014 Our Rating: :: ORGANIZED FINANCESiPhone App - Designed for the iPhone, compatible with the iPad Organize your finances with the quick and easy to use, MonSense.   | Read more »
This Week at 148Apps: October 13-17, 201...
Expert App Reviewers   So little time and so very many apps. What’s a poor iPhone/iPad lover to do? Fortunately, 148Apps is here to give you the rundown on the latest and greatest releases. And we even have a tremendous back catalog of reviews; just... | Read more »
Angry Birds Transformers Review
Angry Birds Transformers Review By Jennifer Allen on October 20th, 2014 Our Rating: :: TRANSFORMED BIRDSUniversal App - Designed for iPhone and iPad Transformed in a way you wouldn’t expect, Angry Birds Transformers is a quite... | Read more »
GAMEVIL Announces the Upcoming Launch of...
GAMEVIL Announces the Upcoming Launch of Mark of the Dragon Posted by Jessica Fisher on October 20th, 2014 [ permalink ] Mark of the Dragon, by GAMEVIL, put | Read more »
Interview With the Angry Birds Transform...
Angry Birds Transformers recently transformed and rolled out worldwide. This run-and-gun title is a hit with young Transformers fans, but the ample references to classic Transformers fandom has also earned it a place in the hearts of long-time... | Read more »

Price Scanner via MacPrices.net

Select MacBook Airs $100 off MSRP, free shipp...
B&H Photo has 2014 a couple of MacBook Airs on sale for $100 off MSRP. Shipping is free, and B&H charges NY sales tax only. They also include free copies of Parallels Desktop and LoJack for... Read more
13-inch 2.5GHz MacBook Pro on sale for $100 o...
B&H Photo has the 13″ 2.5GHz MacBook Pro on sale for $999.99 including free shipping plus NY sales tax only. Their price is $100 off MSRP. Read more
Strong iPhone, Mac And App Store Sales Drive...
Apple on Monday announced financial results for its fiscal 2014 fourth quarter ended September 27, 2014. The Company posted quarterly revenue of $42.1 billion and quarterly net profit of $8.5 billion... Read more
Apple Posts How-To For OS X Recovery
OS X 10.7 Lion and later include OS X Recovery. This feature includes all of the tools you need to reinstall OS X, repair your disk, and even restore from a Time Machine backup. OS X Recovery... Read more
Mac OS X Versions (Builds) Supported By Vario...
Apple Support has posted a handy resource explaining which Mac OS X versions (builds) originally shipped with or are available for your computer via retail discs, downloads, or Software Update. Apple... Read more
Deals on 2011 13-inch MacBook Airs, from $649
Daily Steals has the Mid-2011 13″ 1.7GHz i5 MacBook Air (4GB/128GB) available for $699 with a 90 day warranty. The Mid-2011 13″ 1.7GHz i5 MacBook Air (4GB/128GB SSD) is available for $649 at Other... Read more
2013 15-inch 2.0GHz Retina MacBook Pro availa...
B&H Photo has leftover previous-generation 15″ 2.0GHz Retina MacBook Pros now available for $1599 including free shipping plus NY sales tax only. Their price is $400 off original MSRP. B&H... Read more
Updated iPad Prices
We’ve updated our iPad Air Price Tracker and our iPad mini Price Tracker with the latest information on prices and availability from Apple and other resellers, including the new iPad Air 2 and the... Read more
Apple Pay Available to Millions of Visa Cardh...
Visa Inc. brings secure, convenient payments to iPad Air 2 and iPad mini 3as well as iPhone 6 and 6 Plus. Starting October 20th, eligible Visa cardholders in the U.S. will be able to use Apple Pay,... Read more
Textkraft Pocket – the missing TextEdit for i...
infovole GmbH has announced the release and immediate availability of Textkraft Pocket 1.0, a professional text editor and note taking app for Apple’s iPhone. In March 2014 rumors were all about... Read more

Jobs Board

Senior Event Manager, *Apple* Retail Market...
…This senior level position is responsible for leading and imagining the Apple Retail Team's global event strategy. Delivering an overarching brand story; in-store, Read more
*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
Project Manager / Business Analyst, WW *Appl...
…a senior project manager / business analyst to work within our Worldwide Apple Fulfillment Operations and the Business Process Re-engineering team. This role will work Read more
*Apple* Retail - Multiple Positions (US) - A...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
Position Opening at *Apple* - Apple (United...
…customers purchase our products, you're the one who helps them get more out of their new Apple technology. Your day in the Apple Store is filled with a range of Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.