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.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Shimo 4.0 - VPN Client for Mac – for Eve...
Shimo is the most versatile VPN client for OS X and it enables really everybody to master secure network. It supports more protocols than any other VPN application out there! CiscoVPN, AnyConnect,... Read more
Capo 3.3 - Slow down and learn to play y...
Capo lets you slow down your favorite songs so you can hear the notes and learn how they are played. With Capo, you can quickly tab out your songs atop a highly-detailed OpenCL-powered spectrogram... Read more
MacUpdate Desktop 6.0.8 - Search and ins...
MacUpdate Desktop 6 brings seamless 1-click installs and version updates to your Mac. With a free MacUpdate account and MacUpdate Desktop 6, Mac users can now install almost any Mac app on macupdate.... Read more
BitTorrent Sync 2.1.1 - Sync files secur...
BitTorrent Sync allows you to sync unlimited files between your own devices, or share a folder with friends and family to automatically sync anything. File transfers are encrypted. Your information... Read more
Quicksilver 1.3.0 - Application launcher...
Quicksilver is a light, fast and free Mac application that gives you the power to control your Mac with keystrokes alone. Quicksilver allows you to find what you need quickly and easily, then act... Read more
iWatermark Pro 1.72 - Easily add waterma...
iWatermark Pro is the essential watermarking app for professional, business, and personal use. iWatermark, is the number 1 and only watermarking tool available for all 4 platforms iPhone/iPad, Mac,... Read more
RapidWeaver 6.3 - 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
Adobe Photoshop CC 2015 16.0.1 - Profess...
Photoshop CC 2015 is available as part of Adobe Creative Cloud for as little as $19.99/month (or $9.99/month if you're a previous Photoshop customer). Photoshop CS6 is still available for purchase (... Read more
Together 3.4.6 - Store and organize all...
Together helps you organize your Mac, giving you the ability to store, edit and preview your files in a single clean, uncluttered interface. Smart storage. With simple drag-and-drop functionality,... Read more
Monosnap 3.1.0 - Versatile screenshot ut...
Monosnap lets you capture screenshots, share files, and record video and .gifs! Capture: Capture full screen, just part of the screen, or a selected window Make your crop area pixel perfect with... Read more

.Decluster Zero: Bullet Nocturne (Games...
.Decluster Zero: Bullet Nocturne 1.0.1 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0.1 (iTunes) Description: LAUNCH SALE, 40% off for a limited time -- .Decluster is a Guide for Your Bullet-Hell Dream Tonight --... | Read more »
Five Nights at Freddy's 4 has Been...
In keeping with tradition, Five Nights at Freddy's 4 has made its way to the App Store with zero warning fanfare. Honestly I'd be disappointed it if happened any other way at this point. [Read more] | Read more »
Doom & Destiny Advanced (Games)
Doom & Destiny Advanced 2.3.4.0 Device: iOS Universal Category: Games Price: $.99, Version: 2.3.4.0 (iTunes) Description: ---SUPER GIGA LAUNCH DISCOUNT! Get it now for cheap or pay more later!---An additional 143 MB download is... | Read more »
Five Nights at Freddys 4 (Games)
Five Nights at Freddys 4 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: This time, the terror has followed you home. | Read more »
This Week at 148Apps: July 27-31, 2015
Winding Down July With 148Apps How do you know what apps are worth your time and money? Just look to the review team at 148Apps. We sort through the chaos and find the apps you're looking for. The ones we love become Editor’s Choice, standing out... | Read more »
You'll Want to Keep an Eye Out for...
If you're the kind of person who had fun hunting down and completing all the codex puzzles in Assassin's Creed 2, then are you ever in for a treat. The Guides looks like it's going to be a very robust collection of similarily odd, seemingly... | Read more »
Vivid Games has Announced Real Boxing 2...
The original Real Boxing was a pretty impressive bit of fisticuffs, but if the trailer Vivid Games is showing off for GamesCom is any indication Real Boxing 2 is going to be even better. [Read more] | Read more »
PAC-MAN Championship Edition DX - Tips,...
[Read more] | Read more »
Card King: Dragon Wars - Tips, Tricks an...
[Read more] | Read more »
Pac-Man Championship Edition DX has brou...
Bandai Namco has released Pac-Man Championship Edition DX on iOS and Android, which features the classic arcade gameplay that we've all grown to love. Pac-Man Championship Edition DX can be enjoyed in much shorter bursts than the arcade versions... | Read more »

Price Scanner via MacPrices.net

Back to School Time: Outline for iPad Goes Fr...
Sacramento, California based Gorillized Corporation has announced a “Back to School” offer; the iPad version of Outline goes free for August 3-5. Outline is a smart digital notebook for iPad that... Read more
MacBook 12 Retina Pundit’s New Favorite Mac
If you’re eyeing the purchase of a new 12-inch Retina MacBook, but wondering if you can live with a single USB-C port, 2011-level CPU performance, and the unorthodox keyboard, you should find... Read more
15-inch 2.2GHz Retina MacBook Pro on sale for...
Adorama has the 2015 15″ 2.2GHz Retina MacBook Pro on sale for $184 off MSRP including free shipping plus NY & NJ sales tax only: - 15″ 2.2GHz Retina MacBook Pro: $1815 $184 off Adorama will also... Read more
PDF Element Tool Kit For PDF For Windows 10,...
South Surrey, British Columbia based software developer Wondershare has posted an interesting infographic tracking the development of Microsoft’s flagship Windows operating system over the years,... Read more
27-inch 3.5GHz 5K iMac on sale for $81 off MS...
Adorama has the 27″ 3.5GHz 5K iMac on sale for $2218, $81 off MSRP, including a free copy of Apple’s 3-Year AppleCare Protection Plan. Shipping is free, and Adorama charges sales tax in NY & NJ... Read more
Back-to-School with Tablet and Smartphone Acc...
Belkin helps you prepare for the coming school year with a wide variety of the latest mobile and tablet accessories to outfit both grade school and college students. The line-up includes charging... Read more
11-inch MacBook Airs on sale for $100 off MSR...
Best Buy has 11-inch MacBook Airs on sale for $100 off MSRP. Choose free shipping or free local store pickup (if available). Sale prices for online orders only, in-store prices may vary: - 11″ 1.6GHz... Read more
iPad Air 2 on sale for up to $100 off MSRP
Best Buy has iPad Air 2s on sale for up to $100 off MSRP on their online store for a limited time. Choose free shipping or free local store pickup (if available). Sale prices available for online... Read more
Sale! 13-inch MacBook Pros on sale for $100 o...
B&H Photo has 13″ MacBook Pros on sale for $100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 13″ 2.5GHz/500GB MacBook Pro: $999.99 save $100 - 13″ 2.7GHz/128GB Retina... Read more
Sale! Save $100 on 13-inch MacBook Airs this...
B&H Photo has the 13″ 1.6GHz/128GB MacBook Air on sale for $899.99 including free shipping plus NY tax only. Their price is $100 off MSRP, and it’s the lowest price available for this model.... Read more

Jobs Board

*Apple* Certified Mac Technician - Updated 6...
…and friendly, hands-on technical support to customers troubleshooting and repairing Apple /Mac products with courtesy, speed and skill. Use your problem-solving skills Read more
*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
Infrastructure Engineer - *Apple* /Mac - Hil...
Infrastructure Engineer - Apple /Mac Job Code: 1608 # of openings: 1 Description Our fortune 500 client is looking to hire an experienced Infrastructure Engineer to join Read more
Executive Administrative Assistant, *Apple*...
…supporting presentation development for senior leadership. * User experience with Apple hardware and software is preferred. Additional Requirements The following list Read more
*Apple* Bus Company is now hirin - Apple Bus...
Apple Bus Company is now hiring school bus drivers in the Pettis County area. Class B CDL preferred. Free training provided. No nights or weekends required. Flexible Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.