TweetFollow Us on Twitter

Feb 94 Tips
Volume Number:10
Issue Number:2
Column Tag:Tips & Tidbits

Tips & Tidbits

By Neil Ticktin, Editor-in-Chief

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

Tip Of The Month

Playing a sound can be potentially disastrous. Suppose you have an init that plays a sound when a mail arrives on the network, but at the same time, e.g., HyperCard is playing, an (asynchronous) sound of its own. Both sounds will be stopped by a freeze or a crash.

I looked at the code of the _SysBeep trap, and came up with the ‘SafeSound’-procedure. It will only play the sound when it’s safe to do so. If the routine did not play the sound, it returns false so that you try again after, say, a few seconds.


/* 1 */
#define ExpandMem   0x02B6
#define WWExists   0x08F2

Boolean SafeSound (Handle snd)
{
  asm {
       move SR, D0   ; this little piece of code checks if
       andi.w    #0x0700, D0; we can play our sound !
       bne  @exit    ; Took it from code of the SysBeep-trap!
       movea.l   ExpandMem, A0
       movea.l   0x0110(A0), A0
       tst.w     0x0018(A0)
       beq  @exit
       tst.b     WWExists
       bne  @exit
    }

  SndPlay (NULL, snd, false) ;
  return true ;  // ok, sound is played

exit:
  return false;  // sound has not been played
}

- Jan Bruyndonckx

Wave Research

Belgium

This column is your opportunity to spread the word about little bits of information that you find out about. These tidbits can be programming related or they can be user tips that are particularly useful to programmers.

MacTech Magazine will pay $25 for every tip used, and $50 for the Tip of the Month. Or you can take your award in orders or subscriptions.

To submit a tip, send in a letter to the magazine. E-mail is our preferred method, but feel free to send something via the US Mail. See page two for all addresses. If you do send snail mail, enclose a printed copy and a disk copy of the letter so that it does not have to be retyped.

Changing Popup Fonts

There’s an easy way to change a Popup menu’s font and size. To do that, you could of course use the new CDEF provided with the Comm Toolbox, but it will not work for Pre-System 7 users.

An alternative solution is to change system font and size before PopUpMenuSelect is called, and restore them afterwards. Typical code looks like:

/* 2 */

TYPE
 LomemPtrWord=^Integer;
 LomemPtrLong=^Longint;

VAR
 SysFont, SysSize:Integer;
 PopUpResult:Longint;

{-1 means hierarchical menu}
InsertMenu(MyPopUpID, -1);  

{ Let's save system font and size }
SysFont := LomemPtrWord($0BA6) ^;  {SysFontFam}
SysSize := LomemPtrWord($0BA8) ^;  {SysFontSize}

{Modfy to our convenience (Geneva 10)}
LomemPtrWord($0BA6) ^ := Geneva;
LomemPtrWord($0BA8) ^ := 10;
LomemPtrLong($0B4C) ^ := -1;

{ This line insure that system will }
{ load the right font in the cache }
{ for the next job--drawing my Popup }
ResultPopUp := PopUpMenuSelect(MyPopUpHandle, Where.v, 
 Where.h, DefaultItem);

{ Let's restore system configuration }
LomemPtrWord($0BA6) ^ := SysFont;
LomemPtrWord($0BA8) ^ := SysSize;
LomemPtrLong($0B4C) ^ := -1;

{ Insure that usual system font will be back loaded }
DeleteMenu(MyPopUpID);
{...}
{PopUp Process }
{...} 

Remark 1 : If you’re using CheckItem call, be sure that CheckMark character exists in the font and size you want popup menu to be drawn. If not, use SetItemMark instead.

Remark 2 : Modifying directly low memory globals is discouraged by Apple. Future system releases could break this tip. Keep this in mind.

- Laurent Haas

Paris, France

Often Used Field Positions

For data structures accessed via pointers or handles, place the most often used field in your program in the first place of your data structure declaration.

The Optimal Data Structure Declaration is:

/* 3 */

TYPE
 YourDataStructurePtr = ^YourDataStructure;
 YourDataStructure = RECORD
 often_Used_Field:LongInt;
 less_Often_Used_Field:LongInt;
 END;
Less Optimal Data Structure Declaration:

TYPE
 YourDataStructurePtr = ^YourDataStructure;
 YourDataStructure = RECORD
 less_Often_Used_Field:LongInt;
 often_Used_Field:LongInt;
 END;

The compiler will generate 66% faster code for the optimal data structure when it compiles the next line:

/* 4 */
yourDataStructurePtr^.often_Used_Field:=someValue;

- Marek Hajek

Incline Village, Nevada

It’s in the fine print

The integration of translators in Think C 6.0 has a few rough areas that are not so obvious, unless you read the fine print in the manual. Unless you never make assumptions about how a feature works, read on....

First, if you use both the C and C++ translators in the same project, you could have problems. The C translator allows you to choose whether you want two or four byte integers. The C++ translator doesn’t give you a choice. Integers are always four bytes. So if you want your C code to co-exist peacefully with your C++ code, you must tell the C translator to use four byte integers. Here is the menu/dialog selections you must make to select four byte integers - “Edit:Options:Think C...:Compiler Settings:4-byte ints”

Second, the project settings allow you to put strings in the data segment of the project, or in separate STRS resources. In the “Set Project Type...” option under the “Project” menu, there is a check box “Separate STRS” that you can use to toggle this setting. It isn’t obvious, but this toggle only affects the C translator. To toggle the same setting for the C++ translator you must make the following menu/dialog selections: “Edit:Options:Symantec C++:Compiler Settings:Place string literals in code”.

- Greg Johnson

WordPerfect Corp.

Orem, Utah

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Latest Forum Discussions

See All

Fresh From the Land Down Under – The Tou...
After a two week hiatus, we are back with another episode of The TouchArcade Show. Eli is fresh off his trip to Australia, which according to him is very similar to America but more upside down. Also kangaroos all over. Other topics this week... | Read more »
TouchArcade Game of the Week: ‘Dungeon T...
I’m a little conflicted on this week’s pick. Pretty much everyone knows the legend of Dungeon Raid, the match-3 RPG hybrid that took the world by storm way back in 2011. Everyone at the time was obsessed with it, but for whatever reason the... | Read more »
SwitchArcade Round-Up: Reviews Featuring...
Hello gentle readers, and welcome to the SwitchArcade Round-Up for July 19th, 2024. In today’s article, we finish up the week with the unusual appearance of a review. I’ve spent my time with Hot Lap Racing, and I’m ready to give my verdict. After... | Read more »
Draknek Interview: Alan Hazelden on Thin...
Ever since I played my first release from Draknek & Friends years ago, I knew I wanted to sit down with Alan Hazelden and chat about the team, puzzle games, and much more. | Read more »
The Latest ‘Marvel Snap’ OTA Update Buff...
I don’t know about all of you, my fellow Marvel Snap (Free) players, but these days when I see a balance update I find myself clenching my… teeth and bracing for the impact to my decks. They’ve been pretty spicy of late, after all. How will the... | Read more »
‘Honkai Star Rail’ Version 2.4 “Finest D...
HoYoverse just announced the Honkai Star Rail (Free) version 2.4 “Finest Duel Under the Pristine Blue" update alongside a surprising collaboration. Honkai Star Rail 2.4 follows the 2.3 “Farewell, Penacony" update. Read about that here. | Read more »
‘Vampire Survivors+’ on Apple Arcade Wil...
Earlier this month, Apple revealed that poncle’s excellent Vampire Survivors+ () would be heading to Apple Arcade as a new App Store Great. I reached out to poncle to check in on the DLC for Vampire Survivors+ because only the first two DLCs were... | Read more »
Homerun Clash 2: Legends Derby opens for...
Since launching in 2018, Homerun Clash has performed admirably for HAEGIN, racking up 12 million players all eager to prove they could be the next baseball champions. Well, the title will soon be up for grabs again, as Homerun Clash 2: Legends... | Read more »
‘Neverness to Everness’ Is a Free To Pla...
Perfect World Games and Hotta Studio (Tower of Fantasy) announced a new free to play open world RPG in the form of Neverness to Everness a few days ago (via Gematsu). Neverness to Everness has an urban setting, and the two reveal trailers for it... | Read more »
Meditative Puzzler ‘Ouros’ Coming to iOS...
Ouros is a mediative puzzle game from developer Michael Kamm that launched on PC just a couple of months back, and today it has been revealed that the title is now heading to iOS and Android devices next month. Which is good news I say because this... | Read more »

Price Scanner via MacPrices.net

Amazon is still selling 16-inch MacBook Pros...
Prime Day in July is over, but Amazon is still selling 16-inch Apple MacBook Pros for $500-$600 off MSRP. Shipping is free. These are the lowest prices available this weekend for new 16″ Apple... Read more
Walmart continues to sell clearance 13-inch M...
Walmart continues to offer clearance, but new, Apple 13″ M1 MacBook Airs (8GB RAM, 256GB SSD) online for $699, $300 off original MSRP, in Space Gray, Silver, and Gold colors. These are new MacBooks... Read more
Apple is offering steep discounts, up to $600...
Apple has standard-configuration 16″ M3 Max MacBook Pros available, Certified Refurbished, starting at $2969 and ranging up to $600 off MSRP. Each model features a new outer case, shipping is free,... Read more
Save up to $480 with these 14-inch M3 Pro/M3...
Apple has 14″ M3 Pro and M3 Max MacBook Pros in stock today and available, Certified Refurbished, starting at $1699 and ranging up to $480 off MSRP. Each model features a new outer case, shipping is... Read more
Amazon has clearance 9th-generation WiFi iPad...
Amazon has Apple’s 9th generation 10.2″ WiFi iPads on sale for $80-$100 off MSRP, starting only $249. Their prices are the lowest available for new iPads anywhere: – 10″ 64GB WiFi iPad (Space Gray or... Read more
Apple is offering a $50 discount on 2nd-gener...
Apple has Certified Refurbished White and Midnight HomePods available for $249, Certified Refurbished. That’s $50 off MSRP and the lowest price currently available for a full-size Apple HomePod today... Read more
The latest MacBook Pro sale at Amazon: 16-inc...
Amazon is offering instant discounts on 16″ M3 Pro and 16″ M3 Max MacBook Pros ranging up to $400 off MSRP as part of their early July 4th sale. Shipping is free. These are the lowest prices... Read more
14-inch M3 Pro MacBook Pros with 36GB of RAM...
B&H Photo has 14″ M3 Pro MacBook Pros with 36GB of RAM and 512GB or 1TB SSDs in stock today and on sale for $200 off Apple’s MSRP, each including free 1-2 day shipping: – 14″ M3 Pro MacBook Pro (... Read more
14-inch M3 MacBook Pros with 16GB of RAM on s...
B&H Photo has 14″ M3 MacBook Pros with 16GB of RAM and 512GB or 1TB SSDs in stock today and on sale for $150-$200 off Apple’s MSRP, each including free 1-2 day shipping: – 14″ M3 MacBook Pro (... Read more
Amazon is offering $170-$200 discounts on new...
Amazon is offering a $170-$200 discount on every configuration and color of Apple’s M3-powered 15″ MacBook Airs. Prices start at $1129 for models with 8GB of RAM and 256GB of storage: – 15″ M3... Read more

Jobs Board

*Apple* Systems Engineer - Chenega Corporati...
…LLC,** a **Chenega Professional Services** ' company, is looking for a ** Apple Systems Engineer** to support the Information Technology Operations and Maintenance Read more
Solutions Engineer - *Apple* - SHI (United...
**Job Summary** An Apple Solution Engineer's primary role is tosupport SHI customers in their efforts to select, deploy, and manage Apple operating systems and Read more
*Apple* / Mac Administrator - JAMF Pro - Ame...
Amentum is seeking an ** Apple / Mac Administrator - JAMF Pro** to provide support with the Apple Ecosystem to include hardware and software to join our team and Read more
Operations Associate - *Apple* Blossom Mall...
Operations Associate - Apple Blossom Mall Location:Winchester, VA, United States (https://jobs.jcp.com/jobs/location/191170/winchester-va-united-states) - Apple Read more
Cashier - *Apple* Blossom Mall - JCPenney (...
Cashier - Apple Blossom Mall Location:Winchester, VA, United States (https://jobs.jcp.com/jobs/location/191170/winchester-va-united-states) - Apple Blossom Mall Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.