TweetFollow Us on Twitter

Apr 95 Top 10
Volume Number:11
Issue Number:4
Column Tag:Symantec Top 10

Symantec 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 Steve Howard and Glenn Austin, Symantec Technical Support

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

Due to the frequency of calls and mail on the following problem, we are repeating a question published earlier.

Q: Why do derived classes of ifstream cause a bus error when they read in a stream?

A: Any class indirectly derived from the virtual base class ios needs to explicitly call the constructor for ios to initialize the data stream’s buffer. For example:

class myifstream : public ifstream {
  myifstream(char * s) : ios(&buffer), 
             ifstream(s){}
 }

Q: When I set project options for new projects, the options do not transfer to any of new projects I create. How do I get the options to remain set when I create new projects?

A: The “new project” option will only work if you remove the project model folder for new projects contained within the (Project Models) folder. The THINK Project Manager will then honor the “new project” options.

Q: I am trying to use Gestalt to find out whether the system has asynchronous SCSI abilities, or whether Quickdraw GX is present, but can’t find the right selectors to use. Where do I get this information?

A: There are some Gestalt selectors that are not in GestaltEqu.h. Lists of most known Gestalt selectors and selector codes are available at various ftp sites (see the URL page for possible sites). Once you find the selectors you need, you can add them to GestaltEqu.h, and then re-precompile your MacHeaders, MacHeaders++, and TCLHeaders with the newly-modified GestaltEqu.h.

A simpler way, if your project allows it, would be to add your new selectors into one of your own header files. This would allow you to not need to rebuild your prebuilt header files, as well as allow you to safely replace your GestaltEqu.h with a new one sometime later (without worrying about losing any of your custom-added equates).

To find the answer to your question, we went to MIDnet’s Info-Mac searcher (http://www.mid.net/INFO-MAC) and did a keyword search on gestalt. We found the following file:
ftp://ftp.hawaii.edu/mirrors/info-mac/dev/info/gestalt-selectors-27.hqx
and have excerpted a few useful lines (in Pascal terminology):

const
     gestaltGraphicsVersion = 'grfx';  {Gestalt version selector}
     gestaltSCSI            = 'scsi';  {SCSI Manager attributes}
     gestaltAsyncSCSI       = 0;       {Supports asynchronous SCSI}

The file we found has much more interesting data, so be sure to go see what other selectors might better suit your purposes.

Q: I want to use the 68881 option in my C++ project. What libraries will I need to recompile?

A: To use the 68881 option, turn on “Generate 68881” for both THINK C and C++, then rebuild the following libraries: CPlusLib, ANSI++, unix++, and IOStreams. Some libraries contain both .c and .cp files, and that’s why you’ll need to turn on the option for both C and C++.

Q: How do I get my CIconButtons to print?

A: In VA, create a new subclass of CIconButton, called CPIconButton. Change your icon buttons to type CPIconButton, then save and generate. In TPM, open CPIconButton.h, and add the following method to the class:

 virtual void DrawIcon(Boolean fHilite)
 {
     short   drawState = CalcDrawState(fHilite);

        // Set up the correct icon
     if (printing)
         cicnH = nil;
     else
         cicnH = itsCicnH[drawState];

     BlockMove(&itsIcon[drawState], &icon, kIconBytes);
     Prepare();

       // Let base class hilight only if color hilighting
    CIconPane::DrawIcon(fHilite && colorHilite);
 }

This will force the icon to draw in black & white on the printer, and it will draw correctly on the screen.

Q: I have created a subview that has a CDialogText item and I need a pointer to the item. Can you show me the easiest way to do this?

A: This is a simple two step process. First, get the ID of your CDialogText resource; these IDs are in the generated header file. The header file’s name is the subview name with the word “Items.h” appended (e.g. “SubviewItems.h”). Second, call the FindViewByID method, passing this ID.

#include “SubviewItems.h” // list of resource IDs for objects in the subview
 
CDialogText *myText;
// kMyDialogTextID is found in SubviewItems.h
myText = (CDialogText*)fMain_SubviewName->
                               FindViewByID(kMyDialogTextID);

Q: I am trying to convert a Pascal record that has a data type of Byte into a C++ structure. I am using the C type char as the equivalent of Byte. Why am I getting bizarre results?

A: The Pascal type Byte is equivalent to an unsigned char in C or C++.

Q: How do I get CTable to show only 3 columns, no matter what the size of the window?

A: To make the table show a constant number of columns, override the Draw method and resize the columns based on the current width of the window. For example:

 void CDerivedArray::Draw(Rect *area)
 {
        LongRect r;

        GetFrame(&r); // Get current frame of table pane

        static int oldWidth=0;

        int width=r.right-r.left;  //find width

        if(width!=oldWidth)  //If width hasn’t changed, don’t do anything
        {
                 int numCol=GetColCount();
                 for(int x=0;x<numCol;x++)
                 {
                          SetColWidth(x,width/numCol);
                 }

                    oldWidth=width;  //Update width
        }

         inherited::Draw(area);  //Draw table
 }

Q: I am using the default console window and want to change the foreground and background colors. Is there any way that THINK C will allow me to do that?

A: You cannot change the foreground or background colors on the default console window. You can to control some aspects of the console like the text font, size and face. You can also control how input to the console window is read. For more information on using the console window, you can refer to the Online Documentation that came with your THINK C/ Symantec C++ product or in THINK Reference under “Console Package Intro” and “Console Input Mode”.

Q: I have created a Visual Architect project, added some views and selected generate all. I have not added any of my own code but, when I try to bring the project up to date, I get an error -192 (resource not found). If I have not added code, what causes this error?

A: In VA, you will get this error if you have defined commands that have the following format in the Command Dialog:

 
   In Class:   CMain
   Do:  Open
   View:       None

When that command is generated, VA will attempt to create an Open command and associate it with an existing ‘CVue’ resource. Since you have not assigned a view to the command, there is no corresponding ‘CVue’ resource. Assign a view to the command to alleviate the problem.

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

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

How to become the ultimate robot warrior...
Chrono Strike is a delightfully immersive beat ‘em up with a sense of humor (any game with a good Sims reference gets points in my book). [Read more] | Read more »
Tips and tricks to get a higher score in...
Snow Roll is a devilish endless runner very much in the vein of Flappy Bird. It revels in its dastardly level of difficulty, and doesn’t really care how angry you get at it as it knows you’ll keep coming back for more. [Read more] | Read more »
How to win big in Slots Deluxe
Cheating while gambling is illegal and morally wrong, and in some parts of the world it leads to men with names like Vinnie "Six Knuckles" Manchenzo beating you to a pulp in a dark alley. [Read more] | Read more »
How to take over the world in Dictator 2
Running a country isn't easy - especially when you're a dictator who wants to take over the world and crush everyone in your path while you do it. [Read more] | Read more »
Tips and tricks to get a higher score in...
Tank.iois - you guessed it! - another multiplayer arena battler likeAgar.io and Slither.io. It does differentiate itself by putting you in a tiny tank though, so it's not exactly the same. To help you get that all-important high score, we've got a... | Read more »
How to unlock characters in One Tap Tenn...
As the title suggests, One Tap Tennis requires only a single tap to play its particular brand of tennis, and rewards you with a ton of unlockable characters if you perform well. Fortunately for you, we at 148Apps have got a few tips and tricks to... | Read more »
Grab it now: Game Craft’s Legend of War...
The real time strategy game is now available for you to sink your teeth into, through the App Store and Google Play. Combining elements of skill, strategy and empire building, Legend of War is a real gamers’ game. [Read more] | Read more »
Skateboard Party 3 ft. Greg Lutzka (Gam...
Skateboard Party 3 ft. Greg Lutzka 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: Skateboard Party is back! This third edition of the popular sports franchise features professional skater... | Read more »
Cubious (Games)
Cubious 1.0 Device: iOS Universal Category: Games Price: $.99, Version: 1.0 (iTunes) Description: Cubious – How smart are you? How high is your IQube? Solve the impossible puzzles to find out, and help a lost little cube find his... | Read more »
Goat Simulator Waste of Space (Games)
Goat Simulator Waste of Space 1.1 Device: iOS Universal Category: Games Price: $4.99, Version: 1.1 (iTunes) Description: ** IMPORTANT - SUPPORTED DEVICESiPhone 4S, iPad 2, iPod Touch 5 or better.** | Read more »

Price Scanner via MacPrices.net

Enterprise Workers Pick Technology Over Perks...
New Adobe study shows surprising attitudes about office jobs and where the future of work is heading. Adobe has released survey findings revealing that a surprising 70 percent of U.S. office workers... Read more
Memorial Day Weekend Sale: $50-$100 off 11-in...
B&H Photo has 13″ and 11″ MacBook Airs with 256GB SSDs on sale for $50-$100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 11″ 1.6GHz/256GB MacBook Air: $999 $100 off MSRP... Read more
Memorial Day Weekend Sales: Apple MacBook Pro...
B&H Photo has 13″ and 15″ Retina MacBook Pros on sale for up to $210 off MSRP. Shipping is free, and B&H charges NY tax only: - 15″ 2.2GHz Retina MacBook Pro: $1799 $200 off MSRP - 15″ 2.5GHz... Read more
Memorial Day Weekend Sales: Apple iMacs and M...
Take up to $150 off the price of a new iMac or Mac mini at the following Apple resellers this Memorial Day weekend: iMacs: B&H Photo has 21″ and 27″ iMacs on sale for up to $150 off MSRP... 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
Goal Zero and OtterBox Partner to Expand iPh...
Goal Zero, specialists in portable power, have announced a partnership with OtterBox, brand smartphone case protection, to offer the Slide and Slide Plus Batteries as modules compatible with the new... Read more
15-inch Retina MacBook Pros on sale for up to...
B&H Photo has 15″ Retina MacBook Pros on sale for up to $210 off MSRP. Shipping is free, and B&H charges NY tax only: - 15″ 2.2GHz Retina MacBook Pro: $1799 $200 off MSRP - 15″ 2.5GHz Retina... Read more
Clearance 2015 13-inch MacBook Airs available...
B&H Photo has clearance 2015 13″ MacBook Airs available for $250 off original MSRP. Shipping is free, and B&H charges NY sales tax only: - 13″ 1.6GHz/4GB/128GB MacBook Air (MJVE2LL/A): $799... 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

Jobs Board

*Apple* Solutions Consultant - APPLE (United...
Job Summary As an Apple Solutions Consultant, you'll be the link between our future customers and our products. You'll showcase your entrepreneurial spirit as you Read more
*Apple* Project Engineer - Smart Source Inc...
SmartSource is in need of an Apple Project Engineer for a 12 month contract opportunity in Pittsburg, PA. Role: Apple Project Engineer Location: Pittsburg, PA Read more
Automotive Sales Consultant - Apple Ford Linc...
…you. The best candidates are smart, technologically savvy and are customer focused. Apple Ford Lincoln Apple Valley is different, because: $30,000 annual salary Read more
Service Assistant - *Apple* Chevrolet *App...
Apple Automotive is one of the fastest growing dealer...and it shows. Consider making the switch to the Apple Automotive Group today! At Apple Automotive, we Read more
Editor, *Apple* News - APPLE (United States...
Job Summary The Apple News team is looking for a passionate and knowledgeable editor with experience covering entertainment/pop culture and experience running social Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.