TweetFollow Us on Twitter

Sep 96 Tips
Volume Number:12
Issue Number:9
Column Tag:Tips & Tidbits

Tips & Tidbits

By Steve Sisak

Did You Take Out the Garbage?

A somewhat obscure but useful way of determing whether objects are getting deleted in C++ is to do this:

1. In the class implementation (usually in the header file), add a destructor:

class MyClass
{
public:
   virtual ~MyClass();

2. Don’t implement the destructor; i.e., don’t write the actual code for the destructor method.

3. Run the project. If you get link errors for the destructors, this means that the destructors are getting called (i.e. the objects are getting deleted), which is what you want. If you don’t get a link error, this means that the object never gets deleted, which could signify a possible memory leak.

Jeremy Vineyard

Pre-Flighting EditText

For a program I recently wrote, I wanted to do user input checking for a dialog box as the user was typing into an EditText field. I wrote a routine that figures out what the contents of a specific EditText box will be if the current event is allowed to be processed. I then called the routine from my custom dialog event proc, and analyzed the results. That way, I could easily decide if the user’s action would produce valid results, or if I needed to abort the current event.

IsDlgControl is a simple check for control characters we always want to process. DivineNewItemString is the routine that does all the work. PStrCopy is a little routine for copying Pascal strings; I’m sure other people have better ways of doing this.

Michael Trent

// some control key constants.
#define kEnterKey               3
#define kBackspace              8
#define kTab                    9
#define kReturnKey              13
#define kEscapeKey              27
#define kLeftKey                28
#define kRightKey               29
#define kUpKey                  30
#define kDownKey                31
#define kDelete                 0xFF

/* IsDlgControl
 * Returns true if c is a special control key (say an arrow key, or escape).
 * Otherwise returns false.
 */
Boolean IsDlgControl(char c)
{
        if ((c >= kEscapeKey) && (c <= kDownKey)) return true;
        if ((c == kReturnKey) || (c == kEnterKey) 
        || (c == kDelete) || (c == kBackspace) || (c == kTab))
                  return true;

        return false;
}

/* PStrCpy
 * A little routine to copy Pascal strings. Provided for those people who don’t
 * already use BlockMove() to do this for them ...
 */
void PStrCpy(Str255 s, const Str255 t)
{
        short i;

        for (i=0; i<=s[0]; i++) {
                s[i]=t[i];
        }
}

/* DivineNewItemString
 * Given a DialogPtr, EventPtr and an item number for the active EditText DLOG
 * Item, it returns what the string will be if the current event is processed.
 * It should be called from a custom dialog event proc.
 */
void DivineNewItemString (
     DialogPtr d, EventRecord *e, short item, Str255 output)
{
        short           *TEScrpLength = (short *)0x0AB0;
        DialogRecord    *dr;
        TEHandle        teh;
        char            c;
        Str255          input, text;
        short           selStart, selEnd;
        short           i;
        short           outStrIdx=0;

        short           iType;
        Handle          iHandle;
        Rect            iRect;

                  // get the text string
        GetDItem(d,item,&iType,&iHandle,&iRect);
        GetIText(iHandle,text);

                 // Set the input string
        c = (e->message & charCodeMask);

        if (IsDlgControl(c)) {  // if it’s a control char, return the
                                // item’s text.
                PStrCpy(output,text);
                return;
        } else if (e->modifiers & cmdKey) {
                if  ((c == 'v') || (c == 'V')) {
                // if pasting, get the pasted string.
                        (void)TEFromScrap();
                        HLock(iHandle);
                        iHandle = TEScrapHandle();
                        for (i=0; i< *TEScrpLength; i++) {
                                input[i+1]=((unsigned char *)
                                        (*iHandle))[i];
                        }
                        input[0]=*TEScrpLength;
                        HUnlock(iHandle);
                } else { // if any other command stroke
                        PStrCpy(output,text);
                        return;
                }
        } else {
                  // else, set the input string equal to the new character
                input[0]=1;
                input[1]=(unsigned char) c;
        }

        // get the selection point from the TERec
        dr = (DialogRecord *)d;
        teh = dr->textH;
        selStart=(*teh)->selStart;
        selEnd=(*teh)->selEnd;

        // generate output string:
        //  copy the first bit of text
        for (i=1; i<=selStart; i++) {
                output[++outStrIdx]=text[i];
        }
        //  copy the input string
        for (i=1; i<=input[0]; i++) {
                output[++outStrIdx]=input[i];
        }
        //  copy the last part of text
        for (i=selEnd+1; i<=text[0]; i++) {
                output[++outStrIdx]=text[i];
        }
        //  lastly, set the length
        output[0] = outStrIdx;
}


A Free Tool From Apple

You can use the Finder’s “About this Macintosh” window to see the size your application’s heap, and the amount of free memory that is available in your heap. This information is only updated during idle time, though, so don’t count on it to always be accurate. [Here’s the real tip: use Balloon Help to get a numeric representation of the information. - sgs]

David Lawrence


Avoiding the Menu Item Gotcha

Watch out when using AppendMenu or InsertMenuItem. I’m using AppendMenu to create a popup menu based on user input. Since AppendMenu interprets certain characters as menu attributes (such as command-key equivalents, menu dimming, etc.), if a user enters one of these characters, you will run into a problem with your menu. To avoid this, call AppendMenu or InsertMenuItem with a dummy string such as "\p " (the string must not be empty), and then call SetMenuItemText using the real string, like so:

Str255 theUserName;

// Get the string to display in the menu
theUser->GetUserName (theUserName);

// Append an empty string to the menu
AppendMenu (theMenuHandle, "p\ ");

// Change the menu item to the userName
SetMenuItemText (theMenuHandle, theIndex, theUserName);

Tim Pedone

World’s Most Original Use of ResEdit

If you are looking in the code of a PICT, you can often see a color table with 256 colors even if you use only 2 or 3 colors. This can represent a massive waste of disk space. I tried to find an app to compact the color table but I couldn’t find one - until finally I found ResEdit!

My trick: create a 'cicn' resource in ResEdit, paste in your PICT or draw it, select the part for using in the PICT, copy and paste it into an actual PICT. The only limitation is the maximum size: 64 by 64.

Henri Clerc

No, Wait -
World’s Most Truly Totally Original Use Of ResEdit

This might be one everybody knows, but I just figured it out and it’s saved me a load of time, so here goes.

ResEdit is a Drag-and-Drop application!!! This works for any type of file. No longer must eons be frittered away navigating through countless folders in open dialog boxes to access resource forks of files hidden deep within the murky depths of your hard drive. Just do a Find in the Finder and drag it to ResEdit - I keep an alias on my desktop. Happy hacking!

Joshua “Vampiric Bunny” Glazer

 
AAPL
$95.60
Apple Inc.
-2.55
MSFT
$43.16
Microsoft Corpora
-0.42
GOOG
$571.60
Google Inc.
-15.82

MacTech Search:
Community Search:

Software Updates via MacUpdate

OneNote 15.2 - Free digital notebook fro...
OneNote is your very own digital notebook. With OneNote, you can capture that flash of genius, that moment of inspiration, or that list of errands that’s too important to forget. Whether you’re at... Read more
iStat Menus 4.22 - Monitor your system r...
iStat Menus lets you monitor your system right from the menubar. Included are 8 menu extras that let you monitor every aspect of your system. Some features: CPU -- Monitor cpu usage. 7 display... Read more
Ember 1.8 - Versatile digital scrapbook....
Ember (formerly LittleSnapper) is your digital scrapbook of things that inspire you: websites, photos, apps or other things. Just drag in images that you want to keep, organize them into relevant... Read more
OmniPlan 2.3.6 - Robust project manageme...
With OmniPlan, you can create logical, manageable project plans with Gantt charts, schedules, summaries, milestones, and critical paths. Break down the tasks needed to make your project a success,... Read more
Command-C 1.1.1 - Clipboard sharing tool...
Command-C is a revolutionary app which makes easy to share your clipboard between iOS and OS X using your local WiFi network, even if the app is not currently opened. Copy anything (text, pictures,... Read more
Knock 1.1.7 - Unlock your Mac by knockin...
Knock is a faster, safer way to sign in. You keep your iPhone with you all the time. Now you can use it as a password. You never have to open the app -- just knock on your phone twice, even when it's... Read more
Mellel 3.3.6 - Powerful word processor w...
Mellel is the leading word processor for OS X and has been widely considered the industry standard since its inception. Mellel focuses on writers and scholars for technical writing and multilingual... Read more
LibreOffice 4.3.0.4 - 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
Freeway Pro 7.0 - Drag-and-drop Web desi...
Freeway Pro lets you build websites with speed and precision... without writing a line of code! With it's user-oriented drag-and-drop interface, Freeway Pro helps you piece together the website of... Read more
Drive Genius 3.2.4 - Powerful system uti...
Drive Genius is an OS X utility designed to provide unsurpassed storage management. Featuring an easy-to-use interface, Drive Genius is packed with powerful tools such as a drive optimizer, a... Read more

Latest Forum Discussions

See All

Dawn of the Immortals Review
Dawn of the Immortals Review By Jennifer Allen on July 31st, 2014 Our Rating: :: RESPECTABLE EXPLORATIONUniversal App - Designed for iPhone and iPad Dawn of the Immortals might not re-invent the wheel, but it does tweak it a little... | Read more »
80 Days Review
80 Days Review By Jennifer Allen on July 31st, 2014 Our Rating: :: EPIC ADVENTUREUniversal App - Designed for iPhone and iPad A fantastic and fascinating re-envisioning of the classic novel by Jules Verne, 80 Days is a delightful... | Read more »
Battleheart Legacy Guide
The world of Battleheart Legacy is fun and deep; full of wizards, warriors, and witches. Here are some tips and tactics to help you get the most enjoyment out of this great game. | Read more »
Puzzle Roo Review
Puzzle Roo Review By Jennifer Allen on July 31st, 2014 Our Rating: :: PUZZLE-BASED TWISTUniversal App - Designed for iPhone and iPad A different take on the usual block dropping puzzle game, Puzzle Roo is quite pleasant.   | Read more »
Super Crossfire Re-Release Super Crossfi...
Super Crossfire Re-Release Super Crossfighter Coming Soon, Other Radiangames Titles Go 50% Off Posted by Ellis Spice on July 31st, 2014 [ | Read more »
Hexiled Review
Hexiled Review By Rob Thomas on July 31st, 2014 Our Rating: :: HEX SELLSUniversal App - Designed for iPhone and iPad In space, no one can hear you… spell? Hexiled is a neat concept for a word scramble puzzle, but it doesn’t go too... | Read more »
Summoners War: Sky Arena Passes 10 Milli...
Summoners War: Sky Arena Passes 10 Million Installs! Posted by Jessica Fisher on July 31st, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Deep Loot Review
Deep Loot Review By Jennifer Allen on July 31st, 2014 Our Rating: :: DIVE DEEPUniversal App - Designed for iPhone and iPad Dive deep in this fun explore-em-up that’s a little grind heavy but ultimately quite entertaining.   | Read more »
Despicable Me: Minion Rush is One Year O...
Despicable Me: Minion Rush is One Year Old, Gets its Biggest Update Yet Posted by Jennifer Allen on July 31st, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Fish & Shark Review
Fish & Shark Review By Jordan Minor on July 31st, 2014 Our Rating: :: FLAPPY FISHUniversal App - Designed for iPhone and iPad Fish & Shark’s beauty is only scale deep.   | Read more »

Price Scanner via MacPrices.net

All Over For Tablets Or Just A Maturing, Evol...
CNN’s David Goldman weighs in on tablet sector doom and gloom, asking rhetorically: “Is this the beginning of the end for the tablet?” Answering that, he contends that hysteria and panic are... Read more
Letterspace 1.0.1 – New Free iOS Text Editor...
Bangkok, Thailand based independent developer Sittipon Simasanti has released Letterspace, a new text editor for iPhone, iPad, and iPod touch devices. Letterspace is a note taking app with an... Read more
Save up to $130 on an iPad mini with Apple re...
The Apple Store has Certified Refurbished 2nd generation iPad minis with Retina Displays available for up to $130 off the cost of new models, starting at $339. Apple’s one-year warranty is included... Read more
iPad Cannibalization Threat “Overblown”
Seeking Alpha’s Kevin Greenhalgh observes that while many commentators think Apple’s forthcoming 5.5-inch panel iPhone 6 will cannibalize iPad sales, in his estimation, these concerns are being... Read more
Primate Labs Releases July 2014 MacBook Pro P...
Primate Labs’ John Poole has posted Geekbench 3 results for most of the new MacBook Pro models that Apple released on Tuesday. Poole observes that overall performance improvements for the new MacBook... Read more
Apple Re-Releases Bugfixed MacBook Air EFI Fi...
Apple has posted a bugfixed version EFI Firmware Update 2.9 a for MacBook Air (Mid 2011) models. The update addresses an issue where systems may take longer to wake from sleep than expected, and... Read more
Save $50 on the 2.5GHz Mac mini, plus free sh...
B&H Photo has the 2.5GHz Mac mini on sale for $549.99 including free shipping. That’s $50 off MSRP, and B&H will also include a free copy of Parallels Desktop software. NY sales tax only. Read more
Save up to $140 on an iPad Air with Apple ref...
Apple is offering Certified Refurbished iPad Airs for up to $140 off MSRP. Apple’s one-year warranty is included with each model, and shipping is free. Stock tends to come and go with some of these... Read more
$250 price drop on leftover 15-inch Retina Ma...
B&H Photo has dropped prices on 2013 15″ Retina MacBook Pros by $250 off original MSRP. Shipping is free, and B&H charges NY sales tax only: - 15″ 2.3GHz Retina MacBook Pro: $2249, $250 off... Read more
More iPad Upgrade Musings – The ‘Book Mystiqu...
Much discussed recently, what with Apple reporting iPad sales shrinkage over two consecutive quarters, is that it had apparently been widely assumed that tablet users would follow a two-year hardware... 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
Sr. Product Leader, *Apple* Store Apps - Ap...
**Job Summary** Imagine what you could do here. At Apple , great ideas have a way of becoming great products, services, and customer experiences very quickly. Bring Read more
Sr Software Lead Engineer, *Apple* Online S...
Sr Software Lead Engineer, Apple Online Store Publishing Systems Keywords: Company: Apple Job Code: E3PCAK8MgYYkw Location (City or ZIP): Santa Clara Status: Full Read more
Sr Software Lead Engineer, *Apple* Online S...
Sr Software Lead Engineer, Apple Online Store Publishing Systems Keywords: Company: Apple Job Code: E3PCAK8MgYYkw Location (City or ZIP): Santa Clara Status: Full 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
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.