TweetFollow Us on Twitter

Feb 95 Top 10
Volume Number:11
Issue Number:2
Column Tag:Think Top 10

Think Top 10

This monthly column, written by Symantec’s Technical Support Engineers, aims to provide you with technical information based on the use of Symantec products.

By Mark B. Baldwin and Steve Howard, Symantec Technical Support

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

Q. Why do I get bus errors when I create a CStyleText object by using the constructor with arguments?

A. In the process of upgrading the TCL, constructors with arguments were added to the classes. In this case, constructors with arguments do not create a new handle to a TERec, the macTE data member of the CStyleText object. To work around this, call the constructor with no arguments and call the IStyleTextX() method.

Q. I am having trouble using sizeof() with printf(). For example:

printf("char size is %d.", sizeof(char));

outputs "char size is 0." Why do I get the wrong result?

A. The output is wrong because the return value of the sizeof() function is a size_t (an unsigned long). Use an %ld rather than a %d as a format specifier. Thus, the correct syntax is

"printf ("The size of a char is %ld.", sizeof(char));" 

Q. How can I avoid problems deleting heap objects whose references are on the stack when using exception handling? The pointer (which is on the stack) to the object becomes invalid when the stack unwinds and only the destructors for automatic objects are guaranteed to be called when an exception is thrown.

A. To handle this, declare pointers as volatile. Last month we explained why you should use the volatile type. Below is a practical example. Use volatile file pointers so that stack unwinding does not reset the value of the pointer (prohibiting the file from being closed).

  funClass * volatile funClassPtr;    // Syntax for volatile declaration 
  funClassPtr = NULL;         // Pointer to NULL guarantees delete as safe.
  int myInt = 1;                      // Watch in debugger to see
                                      //   the stack unwind.
  try_ {
    funClassPtr = TCL_NEW(funClass, ());//macro for new operator
    myInt = 2;                          //put new value on stack
    Failure (2, 100);                   // Force exception 
  } 
  catch_all_() {                      //catch block
    
  delete funClassPtr;                 //this calls destructor.
     
     // myInt is reset to 1, delete removes the object from the  heap 
  }
  end_try_                            //end of try block

Q. How can I use exception handling without using the Think Class Library?

A. To use exception handling without the Think Class Library, include BRLib and Exceptions.cp in your project. Also, compile with the directive #define NO_TCL

The four macros used to make exception handling work correctly are:

  AUTO_DESTRUCT_OBJECT
  TCL_NEW
  TCL_END_CONSTRUCTOR
  TCL_START_DESTRUCTOR

The macro AUTO_DESTRUCT_OBJECT will guarantee that the destructor is called for an automatic object on the stack. A destructor will only work on a completely constructed object. TCL_END_CONSTRUCTOR helps the compiler to determine the complete construction of an object.

Here’s an example that shows how the macros are used.

class funClass TCL_AUTO_DESTRUCT_OBJECT //macro in class header  
{ 
public:
    funClass()  {                       // no arg constructor 
    cout<< "In constructor."<<endl;
    char * myStr = new char[64];        // allocate memory 
    TCL_END_CONSTRUCTOR                 // End of the constructor
    }
    virtual ~funClass() {               // virtual destructor 
    TCL_START_DESTRUCTOR                // Beginning of the destructor 
    cout<< "In destructor."<<endl;
    delete [] myStr;                    // deallocate memory 
    } 
};

Q. Where can I get the Quickdraw GX headers?

A. APDA has a Quickdraw GX Developer’s Kit which contains a CD with the electronic versions of Inside Macintosh for GX, headers, required system software components, and excellent examples which are compilable under THINK C or Symantec C++. For ordering information, call (800) 282-2732. [If all you need is the header files, check out the MacTech Magazine online sites. See page 2 for details - Ed stb]

Q. When I build an application with the TCL, the application does not seem to be scriptable. How can I make it scriptable?

A. The default flags for the SIZE Resource of the application are set to not receive Background NULL Events. Make sure that the flags for your application have this bit turned on.

Q. I have a program that I’m converting from DOS and would like to be able to draw some simple graphics to the console window. How can I do that?

A. Don’t do it. If you draw to the console window, you will not receive update events. However, if you just can’t help yourself from going down this path, here is how to do it.

 #include <iostream.h>
    
 WindowPtr myWindow;         // To be used for the console window.
     
 void main (void)    {    
   cout << " ";                //A simple way to show the console.
   myWindow = FrontWindow();   //Get a pointer to the console.
   SetPort(myWindow);          //Set the port for drawing.
   PenNormal();                //Set the pen for drawing.
   LineTo(100,47);             //Draw a line.     
 }

Q. If I am mixing C and C++ code, should I turn on the option to use Native Floating Point format?

A. Yes. Symantec’s C++ compiler is using the Native Floating Point format. To make sure that your floating point calculations give you the expected results, turn on Use Native Floating Point in the options for the C compiler.

Q. Will Symantec be updating the THINK Reference Databases?

A. Yes. THINK Reference is undergoing a massive overhaul. It will be updated for the Universal Headers and the Think Class Library, and will include new databases for C++ Error Messages. As before, references will be hyperlinked for easy access to information.

Special thanks to: Craig Conner, Colen Garoutte-Carson, Rick Hartmann, Michael Hopkins, Scott Morison, Celso Barriga, Kevin Irlen, Yuen Li, and Chris Prinos.

 
AAPL
$99.38
Apple Inc.
-1.37
MSFT
$46.00
Microsoft Corpora
-0.36
GOOG
$569.60
Google Inc.
-7.76

MacTech Search:
Community Search:

Software Updates via MacUpdate

Cocktail 8.0 Beta 2 - General maintenanc...
Cocktail is a general purpose utility for OS X that lets you clean, repair and optimize your Mac. It is a powerful digital toolset that helps hundreds of thousands of Mac users around the world get... Read more
QuickBooks 2015 16.0.0.1352 R1 - Financi...
QuickBooks 2015 helps you manage your business easily and efficiently. Organize your finances all in one place, track money going in and out of your business, and spot areas where you can save.... Read more
Mac DVDRipper Pro 5.0.1 - Copy, backup,...
Mac DVDRipper Pro is the DVD backup solution that lets you protect your DVDs from scratches, save your batteries by reading your movies from your hard disk, manage your collection with just a few... Read more
Apple OS X bash Update 1.0 - Fix for sec...
The OS X bash Update fixes a security flaw in the bash UNIX shell on OS X 10.9.5 (also on OS X 10.8 and 10.7 [see Related Links below]). OS X 10.9.5 or later Downloads for OS X 10.8 and OS X 10.7 in... Read more
SyncTwoFolders 2.0.5 - Syncs two user-sp...
SyncTwoFolders simply synchronizes two folders. It supports synchronization across mounted network drives and it is a possibility to run a simulation showing in a log what will be done. Please visit... Read more
FinderPop 2.5.7 - Classic Mac utility, n...
FinderPop is a Universal preference pane that extends OS X's contextual menus using a FinderPop Items folder much as the Apple Menu Items folder used to do for the Apple menu. It has other features... Read more
VueScan 9.4.45 - Scanner software with a...
VueScan is a scanning program that works with most high-quality flatbed and film scanners to produce scans that have excellent color fidelity and color balance. VueScan is easy to use, and has... Read more
LibreOffice 4.3.2.2 - Free Open Source o...
LibreOffice is an office suite (word processor, spreadsheet, presentations, drawing tool) compatible with other major office suites. The Document Foundation is coordinating development and... Read more
calibre 2.4 - Complete e-library managem...
Calibre is a complete e-book library manager. Organize your collection, convert your books to multiple formats, and sync with all of your devices. Let Calibre be your multi-tasking digital... Read more
Default Folder X 4.6.9b1 - Enhances Open...
Default Folder X attaches a toolbar to the right side of the Open and Save dialogs in any OS X-native application. The toolbar gives you fast access to various folders and commands. You just click... Read more

Latest Forum Discussions

See All

Manage Your Cloud – Wunderlist Now Suppo...
Manage Your Cloud – Wunderlist Now Supports Dropbox Posted by Jessica Fisher on October 1st, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Nexticy Review
Nexticy Review By Jennifer Allen on October 1st, 2014 Our Rating: :: IDEAL FORM CREATIONiPad Only App - Designed for the iPad Nexticy allows you to make your own forms for research purposes or to organize your business better. It’s... | Read more »
Tiny Troopers: Alliance Marches onto the...
Tiny Troopers: Alliance Marches onto the App Store Tomorrow Posted by Jessica Fisher on October 1st, 2014 [ permalink ] Tiny Troopers: Alliance, by Kukouri, is a | Read more »
HeroCraft Introduces Unlimited Sequel to...
HeroCraft Introduces Unlimited Sequel to WW2: Sandbox. Strategy & Tactics Posted by Jessica Fisher on October 1st, 2014 [ permalink ] | Read more »
RGB Express Review
RGB Express Review By Jennifer Allen on October 1st, 2014 Our Rating: :: DELIGHTFUL PUZZLINGUniversal App - Designed for iPhone and iPad Guide trucks along their delivery routes in RGB Express, a testing but charming puzzle game... | Read more »
The Sagas of Fire*Wolf (Games)
The Sagas of Fire*Wolf 1.0 Device: iOS Universal Category: Games Price: $9.99, Version: 1.0 (iTunes) Description: | Read more »
BuggyFun Review
BuggyFun Review By Amy Solomon on October 1st, 2014 Our Rating: iPad Only App - Designed for the iPad BuggyFun allows children to create their own tracks for bugs to interact with for a unique open-ended experience.   | Read more »
Fold the Adventure Review
Fold the Adventure Review By Jennifer Allen on October 1st, 2014 Our Rating: :: AWKWARD FOLDSUniversal App - Designed for iPhone and iPad Fold pieces of paper to create platforms for a princely rabbit in this puzzle game; something... | Read more »
WW2: Sandbox. Strategy & Tactics (G...
WW2: Sandbox. Strategy & Tactics 1.0.0 Device: iOS Universal Category: Games Price: $9.99, Version: 1.0.0 (iTunes) Description: ***NOTE: Compatible with iPhone 4s and up, iPad 2 and up - may not work properly on earlier devices... | Read more »
apeFilter (Music)
apeFilter 1.0 Device: iOS Universal Category: Music Price: $6.99, Version: 1.0 (iTunes) Description: | Read more »

Price Scanner via MacPrices.net

Amazon offers 13-inch MacBook Air for $899, $...
Amazon.com has the 13″ 1.4GHz 128GB MacBook Air on sale for $100 off MSRP including free shipping: - 13″ 1.4GHz 128GB MacBook Air: $899.99 Read more
Apple resting On Its iPhone Laurels? – The ‘B...
Apple calls its new iPhone 6 and 6 Plus “The Biggest Advancements in iPhone History,” but does reality live up to the hype? “Seldom have so many waited so breathlessly for so little,” tweeted veteran... Read more
Roundup of Apple Mac and iPad Education disco...
Purchase a new Mac or iPad at The Apple Store for Education and take up to $300 off MSRP. All teachers, students, and staff of any educational institution qualify for the discount. Shipping is free,... Read more
Apple Boycotts German Magazine Computer Bild...
Apple has revoked its PR accreditation of Germany’s Computer Bild, Europe’s best-selling PC magazine, in reaction to Bild’s posting of a “#Bentgate” YouTube video. Axel Telzerow, editor in chief of... Read more
iPhone 6 & iPhone 6 Plus Available in Chi...
Apple has announced that iPhone 6 and iPhone 6 Plus will be available in China beginning Friday, October 17 from the Apple Online Store (http://www.apple.com), Apple’s retail stores, and an expansive... Read more
MacBook Airs on sale for $100 off MSRP, start...
Best Buy has the new 2014 MacBook Airs on sale for $100 off MSRP on their online store. Choose free home shipping or free local store pickup (if available). Prices valid for online orders only, in-... Read more
Apple Releases OS X Mavericks bash Update 1.0...
Apple has released a patch update for OS X Mavericks users to address the recently-detected “Shellshock” security bug in BSD UNIX’s bash shell. Apple says only a few Mac users who had manually... Read more
Pivotal Payments Ready for Apple Pay – FlexPo...
Pivotal Payments, a provider of merchant services and global payment processing solutions, has announced its proprietary FlexPoint platform will support credit and debit transactions through Apple’s... Read more
iStabilizer Announces Tabarm — First Friction...
iStabilizer, a specialist in universal lightweight compact tripods, steady cams, dollies, mounts, and remotes for smartphones, tablets, and cameras, announced today the iStabilizer tabArm, the first... Read more
IStabilizer Flex Smartphone Tripod Wins Usa T...
iStabilizer, a specialist in universal lightweight compact tripods, steady cams, and other products for smartphones, tablets, and cameras, has announced today that its iStabilizer Flex smartphone... Read more

Jobs Board

*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the 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
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
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.