TweetFollow Us on Twitter

Finder Strings
Volume Number:9
Issue Number:4
Column Tag:Fun Hacks

Related Info: Finder Interface

Rändóm fiNdEr sgnirtS

A cute extension to help you with April Fools Day

By By Mike Scanlin, MacTech Magazine Regular Contributing Author

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

Recently at a friend’s house I saw a clock that ticks backwards. The whole thing looks like a normal clock would when viewed in a mirror. I thought to myself “Not very useful, is it? Kind of difficult to figure out what time it is. What if everything was backwards: newspapers, controls on my car, file names in the Finder... <click> Hey! Cool idea for an April Fool’s INIT.” And, so, here we are.

RandomFinderStrings is an INIT (Extension) that causes one of several effects to happen to each string drawn by the Finder: (1) the case of the letters is forced to be upper, lower, reversed or random, (2) the letters in the string are rearranged back-to-front, (3) all vowels get an accent mark or (4) all vowels are removed. The effect that happens to each string is random. The framework of the code has been set up to make it easy to add your own effects if you can think of a cool way to tweak a Str255 (maybe you could do a conversion to Pig Latin or something) or, you can just use the code as it appears here. You can have some fun if you give this INIT an unsuspecting name like “Easy Access” and put it on a [former?] friend’s Mac.

HOW DOES IT WORK?

The first part of the INIT code creates space for the patch and effects code in the system heap (about 800 bytes) and moves a copy of the code there. Then it installs a head patch on DrawString. The patched DrawString will first check if CurApName == “\pFinder” and that the Option key is not down. If both conditions are true then it will randomly change a copy of the string before calling the real DrawString to draw the string. Note that comment about the Option key. If you really need to see the true strings once this INIT is installed, and you can’t afford to remove it and reboot, you can hold down the Option key and cause the screen to refresh (with a screen saver)-everything will redraw normally (but if you let go of the option key then things begin to get drawn tweaked again).

WHAT DOES IT LOOK LIKE?

Here are some screen shots that show some of the effects this INIT is capable of. Figure 1 shows the System Folder when ACCENTED_VOWELS is on, figure 2 shows the About This Macintosh box when BACKWARDS_LETTERS is on and, figure 3 shows the File menu when DO_CASE_CHANGES is on (the NO_VOWELS option isn’t shown here). You can mix and match these effects until you reach the level of annoyance you desire but you will have to recompile each time you change which effects are on/off. You turn them off by setting their #defined values to 0 and you turn them on by setting their #defined values to 1. If ALWAYS_TWEAK_STRING is off (i.e. zero) then not every string drawn by the Finder will be modified (because of the -1 case in the main switch statement).

Figure 1

Figure 2

Figure 3

Except for maybe the trap patching, this code is pretty easy to understand. The actual effects that tweak the copy of the string are rather simple. One thing to note might be the politically correct way to check if the Option key is down at a time when we don’t have an EventRecord: We make a dummy event record and call OSEventAvail with a mask of zero. This is a much better method than using GetKeys.

Because this is an INIT, the Think C Project Type should be “Code Resource” and the File Type should be “INIT”. You can use whatever you want for the Creator and ID (I used “Twen” with an ID of 55). Have fun.

/*************************************************
 * RandomFinderStrings.c
 *
 * This INIT installs a patch on DrawString that will tweak 
 * strings drawn by the Finder. If CurApName != “/pFinder” 
 * or if the option key is down then a normal DrawString 
 * takes place. If we are in the Finder then a modified 
 * version of the string is drawn: the upper/lower case of 
 * the letters might be changed, the string might be flipped 
 * backwards, all the vowels might get accent marks, etc.
 *
 * You can add to the list of effects by adding an item to 
 * the Effects enum and the main switch statement in 
 * MyDrawString. If your effects need globals, put them in 
 * the PatchGlobals struct and initialize them in main.
 *
 * In Think C, set the Project Type to Code Resource, the 
 * File Type to INIT, the Creator to anything, the Type to 
 * INIT, the ID to something like 55 (55 will work but it
 * doesn’t have to be 55), turn Custom Header ON and Attrs 
 * to 20 (purgeable) and Multi Segment OFF.
 *
 * Mike Scanlin. 24 Jan 1993.
 ***********************************************
 * defines
 ************************************************/
#define _DrawString         0xA884

enum Effects {
    UpperCase = 0,
    LowerCase,
    ReverseCase,
    RandomCase,
    BackwardsLetters,
    AccentedVowels,
    NoVowels,
    PigLatin,
    NumEffects /* must be last */
};

/* Turn these all on for maximum randomness */
#define DO_CASE_CHANGES     1
#define BACKWARDS_LETTERS   1
#define ACCENTED_VOWELS     1
#define NO_VOWELS           1
#define PIG_LATIN           0

#define ALWAYS_TWEAK_STRING 1

#if ALWAYS_TWEAK_STRING && !(DO_CASE_CHANGES || \
    BACKWARDS_LETTERS || ACCENTED_VOWELS || NO_VOWELS)
    not!
    /* Generate a compile time error if you set up an 
     * impossible situation. You need to have at least one 
     * effect enabled if ALWAYS_TWEAK_STRING is enabled. */
#endif

/*************************************************
 * typedefs
 ************************************************/
typedef pascal void (*DSProcPtr)(Str255 *theStringPtr);

typedef struct PatchGlobals {
    DSProcPtr       pgOldDS;
} PatchGlobals, *PatchGlobalsPtr;

/*************************************************
 * prototypes
 ************************************************/
void main(void);
void StartPatchCode(void);
pascal void MyDrawString(Str255 *theStringPtr);
short abs(short n);
void EndPatchCode(void);

/******************** main ***********************
 * Gets some memory in the system heap and installs the 
 * DrawString patch (as well as allocating and initializing 
 * the patch globals).  This is the only routine that gets 
 * executed at startup time (by the INIT mechanism).
 *
 * The block of memory that main allocates will
 * look like this when main has finished:
 *
 *                   +--------------------+
 *                   |    PatchGlobals    |
 *                   +--------------------+
 *                   |  StartPatchCode()  |
 *   DS trap addr -> +--------------------+
 *                   |   MyDrawString()   |
 *                   +--------------------+
 *                   |       abs()        |
 *                   +--------------------+
 *                   |   EndPatchCode()   |
 *                   +--------------------+
 ************************************************/
void main()
{
    Ptr             patchPtr;
    PatchGlobalsPtr pgPtr;
    long            codeSize, offset;
        
    /* try and get some memory in the system heap
     * for code and globals */
    codeSize = (long) EndPatchCode -
        (long) StartPatchCode;
    patchPtr = NewPtrSys(codeSize +
        sizeof(PatchGlobals));
    if (!patchPtr)
        return; /* out of memory-abort patching */
    
    /* initialize the patch globals at the
     * beginning of the block */
    pgPtr = (PatchGlobalsPtr) patchPtr;
    pgPtr->pgOldDS = (DSProcPtr)
        GetTrapAddress(_DrawString);
    
    /* move the code into place after the globals */
    BlockMove(StartPatchCode, patchPtr +
        sizeof(PatchGlobals), codeSize);
    
    /* set the patches */
    patchPtr += sizeof(PatchGlobals);
    offset = (long) MyDrawString -
        (long) StartPatchCode;
    SetTrapAddress((long) patchPtr + offset,
        _DrawString);
}

/***************** StartPatchCode ****************
 * Dummy proc to mark the beginning of the code 
 * for the patches. Make sure all of your patch
 * code is between here and EndPatchCode.
 ************************************************/
void StartPatchCode()
{
}

/*********************** MyDrawString **********************
 * Head patch on DrawString that randomly tweaks the string 
 * to be drawn if the current application is the Finder and 
 * the Option key is not down.
***********************************************************/
pascal void MyDrawString(Str255 *theStringPtr)
{
    Str255          copyOfString;
    EventRecord     theEvent;
    PatchGlobalsPtr pgPtr;
    Byte            *p, *inputPtr;
    short           rand;
    Byte            i, ch;
        
    /* if we’re not in the Finder then exit */
    if (*(char *) &CurApName != 6 ||
      *(long *) ((Ptr) &CurApName + 1) != ‘Find’ ||
      *(short *) ((Ptr) &CurApName + 5) != ‘er’ )
        goto DontDoAnything;
    
    /* if the option key is down then exit */
    OSEventAvail(0, &theEvent);
    if (theEvent.modifiers & optionKey)
        goto DontDoAnything;
    
    /* we’re in the Finder so do something to a
     * copy of the string (unless it’s zero-length) */
    if (i = *(Byte *) theStringPtr) {
        p = (Byte *) &copyOfString;
        BlockMove(theStringPtr, p++, i + 1);

TryAgain:

        switch (abs(Random()) % NumEffects) {
        
#if DO_CASE_CHANGES
        case UpperCase:
            /* force all letters to upper case */
            do {
                if (*p >= ‘a’ && *p <= ‘z’)
                    *p -= ‘a’ - ‘A’;
                p++;
            } while (-i);
            break;
            
        case LowerCase:
            /* force all letters to lower case */
            do {
                if (*p >= ‘A’ && *p <= ‘Z’)
                    *p += ‘a’ - ‘A’;
                p++;
            } while (-i);
            break;
            
        case ReverseCase:
            /* flip the upper/lower case of each letter */
            do {
                if (*p >= ‘a’ && *p <= ‘z’)
                    *p -= ‘a’ - ‘A’;
                else if (*p >= ‘A’ && *p <= ‘Z’)
                    *p += ‘a’ - ‘A’;
                p++;
            } while (-i);
            break;
            
        case RandomCase:
            /* randomly set the case of each letter */
            do {
                /* force to lower case */
                if (*p >= ‘A’ && *p <= ‘Z’)
                    *p += ‘a’ - ‘A’;
                /* make half of them upper case */
                if (*p >= ‘a’ && *p <= ‘z’ && Random() < 0)
                    *p -= ‘a’ - ‘A’;
                p++;
            } while (-i);
            break;
#endif

#if BACKWARDS_LETTERS
        case BackwardsLetters:
            /* flip the string front to back */
            inputPtr = (Byte *) theStringPtr + i;
            do {
                *p++ = *inputPtr;
                inputPtr-;
            } while (-i);
            break;
#endif

#if ACCENTED_VOWELS
        case AccentedVowels:
            /* put an accent mark over each vowel */
            do {
                rand = abs(Random());
                switch (*p) {
                case ‘A’:
                    switch (rand & (4-1)) {
                    case 0: *p = 0x80; break;
                    case 1: *p = 0x81; break;
                    case 2: *p = 0xCB; break;
                    case 3: *p = 0xCC; break;
                    }
                    break;
                case ‘E’:
                    *p = 0x83;
                    break;
                case ‘O’:
                    if (Random() < 0)
                        *p = 0x85;
                    else
                        *p = 0xCD;
                    break;
                case ‘U’:
                    *p = 0x86;
                    break;
                case ‘a’:
                    *p = 0x87 + (rand % 6);
                    break;
                case ‘e’:
                    *p = 0x8E + (rand & (4-1));
                    break;
                case ‘i’:
                    *p = 0x92 + (rand & (4-1));
                    break;
                case ‘o’:
                    *p = 0x97 + (rand % 5);
                    break;
                case ‘u’:
                    *p = 0x9C + (rand & (4-1));
                    break;
                default:
                    break;
                }
                p++;
            } while (-i);
            break;
#endif

#if NO_VOWELS
        case NoVowels:
            /* remove all vowels */
            inputPtr = (Byte *) theStringPtr + 1;
            do {
                ch = *inputPtr;
                if (ch >= ‘A’ && ch <= ‘Z’)
                    ch += ‘a’ - ‘A’;
                if (ch == ‘a’ || ch == ‘e’ || ch == ‘i’
                  || ch == ‘o’ || ch == ‘u’)
                    copyOfString[0]-;
                else
                    *p++ = *inputPtr;
                inputPtr++;
            } while (-i);
            /* make sure the string length is at least 1 */
            if (copyOfString[0] == 0) {
                copyOfString[0] = 1;
                copyOfString[1] = 
 *((Byte *) theStringPtr + 1);
            }
            break;
#endif

#if PIG_LATIN
        case PigLatin:
            /* not implemented */
            break;
#endif

        case -1:                    
        default:
#if ALWAYS_TWEAK_STRING
            goto TryAgain;
#endif
            break;
        }
        
        theStringPtr = &copyOfString;
    }

DontDoAnything:
    
    /* find our globals */
    pgPtr = (PatchGlobalsPtr) ((long) StartPatchCode -
        sizeof(PatchGlobals));

    /* call the real DrawString */
    (*pgPtr->pgOldDS)(theStringPtr);
}

/********************* abs **********************
 * Return the absolute value of n.
 ************************************************/
short
abs(short n)
{
    if (n < 0)
        return (-n);
    return (n);
}


/******************* EndPatchCode ********************
 * Dummy proc to mark the end of the code for
 * the patches. Make sure all of your patch code
 * is between here and StartPatchCode.
 ************************************************/
void EndPatchCode()
{
}

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Posterino 3.3.6 - Create posters, collag...
Posterino offers enhanced customization and flexibility including a variety of new, stylish templates featuring grids of identical or odd-sized image boxes. You can customize the size and shape of... Read more
Together 3.8.3 - 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. Features Smart storage. With simple drag-and-drop... Read more
iClock Pro 3.4.9 - Customize your menuba...
iClock Pro is a menu bar replacement clock for Apple's default clock. iClock Pro is an update, total rewrite and improvement to the popular iClock. Have the day, date and time in different fonts and... Read more
Things 2.8.12 - Elegant personal task ma...
Things is a task management solution that helps to organize your tasks in an elegant and intuitive way. Things combines powerful features with simplicity through the use of tags and its intelligent... Read more
Typinator 7.2 - Speedy and reliable text...
Typinator turbo-charges your typing productivity. Type a little. Typinator does the rest. We've all faced projects that require repetitive typing tasks. With Typinator, you can store commonly used... Read more
Spotify 1.0.53.758. - Stream music, crea...
Spotify is a streaming music service that gives you on-demand access to millions of songs. Whether you like driving rock, silky R&B, or grandiose classical music, Spotify's massive catalogue puts... Read more
beaTunes 4.6.14 - Organize your music co...
beaTunes is a full-featured music player and organizational tool for music collections. How well organized is your music library? Are your artists always spelled the same way? Any R.E.M. vs REM?... Read more
Vienna 3.1.10 :d05d7a5d: - RSS and Atom...
Vienna is a freeware and Open-Source RSS/Atom newsreader with article storage and management via a SQLite database, written in Objective-C and Cocoa, for the OS X operating system. It provides... Read more
Day One 2.1.8 - Maintain a daily journal...
Day One is the easiest and best-looking way to use a journal / diary / text-logging application for the Mac. Day One is well designed and extremely focused to encourage you to write more through... Read more
iDefrag 5.1.8 - Disk defragmentation and...
iDefrag helps defragment and optimize your disk for improved performance. Features include: Supports HFS and HFS+ (Mac OS Extended). Supports case sensitive and journaled filesystems. Supports... Read more

Latest Forum Discussions

See All

Fantasy MMORPG MU Origin adds new modes,...
MU Origin, Webzen’s highly popular fantasy MMORPG is getting ready to shake things up for the second time this year, as a new update makes its way to the Google Play and App Store from today. Introducing new systems, modes, and events, the land of... | Read more »
Blizzard is looking to hire a mobile dev...
A new thread on the popular video game rumor forum, NeoGAF, uncovered an interesting job listing over at Blizzard Entertainment. It appears the studio behindStarCraft, World of WarCraft, Hearthstone,andOverwatch is looking to bring on a new hire... | Read more »
Legend of Zelda meets Cooking Mama in ne...
Dungeon Chef is what happens when you mix the RPG elements (and style) of a Legend of Zelda game, with cooking elements. Although, now that The Legend of Zelda: Breath of the Wild also has cookingelements, so maybe the gameplay is not so novel.... | Read more »
ChordFlow (Music)
ChordFlow 1.0.0 Device: iOS Universal Category: Music Price: $6.99, Version: 1.0.0 (iTunes) Description: ChordFlow is a chord sequencer with a unique 4-track polyphonic arpeggiator, extensive chord library, MIDI out and Ableton Link... | Read more »
The Walking Dead: A New Frontier is out...
The newest season of Telltale Games'The Walking Dead is well underway. After the release of the third episode, "Above the Law" about a month ago, episode four, "Thicker Than Water" is hot and ready for more zombies and gut-wrenching emotional... | Read more »
Best games we played this week
Another week, another new wave of mobile games do dive into. We've dug through the list of apps that came out this week to tell you which apps are worth your sweet time. And while there weren't too many games this week, there were some big ones.... | Read more »
Vignettes (Games)
Vignettes 1.0.1 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0.1 (iTunes) Description: Vignettes is a casual but unique exploration game without text or characters, where objects shapeshift as you spin them around... | Read more »
Get Me Outta Here is an 80s retro shoote...
Are you ready to fight some aliens? Because Crescent Moon Games has released the retro shooter Get Me Outta Here on iOS devices today. [Read more] | Read more »
Get a bunch of Apple productivity apps f...
If you're an Apple Mac owner, you're probably aware of the host of Apple productivity apps the company includes in all new Mac purchases. Apps like iMovie, Keynote, and of course, GarageBand. While you used to be able to also buy these apps... | Read more »
Terra Mystica (Games)
Terra Mystica 1.03 Device: iOS Universal Category: Games Price: $9.99, Version: 1.03 (iTunes) Description: Short Summary:≈≈≈≈≈≈≈≈≈≈≈≈≈ | Read more »

Price Scanner via MacPrices.net

HyperX Ships Pulsefire FPS Gaming Mouse, Winn...
Your reporter is a longtime fan of gaming mice for general purpose coomnputing use, finding them typically superior in comfort and performance. HyperX, a division of Kingston Technology Company, Inc... Read more
Penske Truck Leasing Unveils “Penske Fleet” M...
Penske Truck Leasing has introduced a free mobile app called “Penske Fleet” to benefit its full-service truck leasing and contract maintenance customers. The mobile app enables Penske’s customers to... Read more
DEVONthink To Go 2.1.3 For iOS Adds New Declu...
DEVONtechnologies has updated DEVONthink To Go, its iOS companion to DEVONthink for Mac. Enhancements and bug fixes in Version 2.1.3 include DEVONtechnologies’ new decluttering service for clipping... Read more
Use Apple’s Education discount to save up to...
Purchase a new Mac or iPad using Apple’s Education Store 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 refurbished Apple Watches available sta...
Apple is now offering Certified Refurbished Series 1 and Series 2 Apple Watches for 14-16% off MSRP, starting at $229. An Apple one-year warranty is included with each watch. Shipping is free: Series... Read more
15-inch Touch Bar MacBook Pros, Apple refurbi...
Apple is offering Certified Refurbished 2016 15″ Touch Bar MacBook Pros for $360 to $420 off original MSRP. An Apple one-year warranty is included with each model, and shipping is free: - 15″ 2.6GHz... Read more
13-inch MacBook Airs on sale for up to $150 o...
Overstock.com has 13″ MacBook Airs on sale for up to $150 off MSRP including free shipping: - 13″ 1.6GHz/128GB MacBook Air (sku MMGF2LL/A): $869.99 $130 off MSRP - 13″ 1.6GHz/256GB MacBook Air (sku... Read more
15-inch Touch Bar MacBook Pros on sale for $1...
B&H Photo has the new 2016 15″ Apple Touch Bar MacBook Pros in stock today and on sale for up to $200 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 15″ 2.7GHz Touch Bar... Read more
15-inch 2.7GHz Touch Bar MacBook Pros on sale...
Amazon has 2016 15″ 2.7GHz Apple Touch Bar MacBook Pros in stock today and on sale for $150-$200 off MSRP. Shipping is free: - 15″ 2.7GHz Touch Bar MacBook Pro Space Gray (sku MLH42LL/A): $2599 $200... Read more
Apple now offering Certified Refurbished 13-i...
Apple is now offering Certified Refurbished 2016 13″ Touch Bar MacBook Pros for $270-$300 off original MSRP. An Apple one-year warranty is included with each model, and shipping is free: - 13″ 2.9GHz... Read more

Jobs Board

Music Marketing Lead, iTunes & *Apple*...
# Music Marketing Lead, iTunes & Apple Music Job Number: 56868140 Culver City, California, United States Posted: Apr. 17, 2017 Weekly Hours: 40.00 **Job Summary** Read more
Best Buy *Apple* Computing Master - Best Bu...
**498001BR** **Job Title:** Best Buy Apple Computing Master **Location Number:** 000356-Manassas-Store **Job Description:** **What does a Best Buy Apple Read more
*Apple* Mac Computer Technician - GeekHampto...
…complex computer issues over the phone and in person? GeekHampton, Long Island's Apple Premium Service Provider, is looking for you! Come work with our crew Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
Music Marketing Lead, iTunes & *Apple*...
# Music Marketing Lead, iTunes & Apple Music Job Number: 56868140 Culver City, California, United States Posted: Apr. 17, 2017 Weekly Hours: 40.00 **Job Summary** Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.