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()
{
}

 
AAPL
$524.94
Apple Inc.
+5.93
MSFT
$40.01
Microsoft Corpora
-0.39
GOOG
$536.10
Google Inc.
-20.44

MacTech Search:
Community Search:

Software Updates via MacUpdate

VMware Fusion 6.0.3 - Run Windows apps a...
VMware Fusion allows you to create a Virtual Machine on your Mac and run Windows (including Windows 8.1) and Windows software on your Mac. Run your favorite Windows applications alongside Mac... Read more
Tweetbot 1.5.1 - Popular iOS twitter cli...
Tweetbot is a full-featured OS X Twitter client with a lot of personality. Whether it's the meticulously-crafted interface, sounds and animation, or features like multiple timelines and column views... Read more
Mac DVDRipper Pro 4.1.7 - Copy, backup,...
Mac DVDRipper Pro is the DVD backup solution that lets you protect your DVDs from scratches, save your batteries by reading your movies from your hard disk, manage your collection with just a few... Read more
PDFpenPro 6.2 - Advanced PDF toolkit for...
PDFpenPro allows users to edit PDF's easily. Add text, images and signatures. Fill out PDF forms. Merge or split PDF documents. Reorder and delete pages. Even correct text and edit graphics! Create... Read more
PDFpen 6.2 - Edit and annotate PDFs with...
PDFpen allows users to easily edit PDF's. Add text, images and signatures. Fill out PDF forms. Merge or split PDF documents. Reorder and delete pages. Even correct text and edit graphics! Features... Read more
Monolingual 1.5.9 - Remove unwanted OS X...
Monolingual is a program for removing unnecesary language resources from OS X, in order to reclaim several hundred megabytes of disk space. It requires a 64-bit capable Intel-based Mac and at least... Read more
Maya 2015 - Professional 3D modeling and...
Maya is an award-winning software and powerful, integrated 3D modeling, animation, visual effects, and rendering solution. Because Maya is based on an open architecture, all your work can be scripted... Read more
Starcraft II: Wings of Liberty 1.1.1.180...
Download the patch by launching the Starcraft II game and downloading it through the Battle.net connection within the app. Starcraft II: Wings of Liberty is a strategy game played in real-time. You... Read more
Sibelius 7.5.0 - Music notation solution...
Sibelius is the world's best-selling music notation software for Mac. It is as intuitive to use as a pen, yet so powerful that it does most things in less than the blink of an eye. The demo includes... Read more
Typinator 5.9 - 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

Latest Forum Discussions

See All

This Week at 148Apps: April 14-18, 2014
Spring Into Our App Reviews   | Read more »
Have a Special Dead Trigger 2 Easter Bas...
Have a Special Dead Trigger 2 Easter Basket Full of Goodies, Courtesy of Madfinger Games Posted by Rob Rich on April 18th, 2014 [ permalink ] Dead Trigger 2 | Read more »
Almost All of Playdek’s Library is on Sa...
Almost All of Playdek’s Library is on Sale Right Now, and You Should Check it Out Posted by Rob Rich on April 18th, 2014 [ permalink ] Playdek has released quite a few great iOS ports of board and card games over the years, and now most of them... | Read more »
Zynga Launches Brand New Farmville Exper...
Zynga Launches Brand New Farmville Experience with Farmville 2: Country Escape Posted by Tre Lawrence on April 18th, 2014 [ permalink ] | Read more »
David. Review
David. Review By Cata Modorcea on April 18th, 2014 Our Rating: :: MINIMALISTIC IN A DIFFERENT WAYUniversal App - Designed for iPhone and iPad David is a minimalistic game wrapped inside of a soothing atmosphere in which the hero... | Read more »
Eyefi Unveils New Eyefi Cloud Service Th...
Eyefi Unveils New Eyefi Cloud Service That Allows Users to Share Media Across Personal Devices Posted by Tre Lawrence on April 18th, 2014 [ permalink ] | Read more »
Tales from the Dragon Mountain: The Lair...
Tales from the Dragon Mountain: The Lair Review By Jennifer Allen on April 18th, 2014 Our Rating: :: STEADY ADVENTURINGiPad Only App - Designed for the iPad Treading a safe path, Tales from the Dragon Mountain: The Lair is a... | Read more »
Yahoo Updates Flickr App with Advanced E...
Yahoo Updates Flickr App with Advanced Editing Features and More Posted by Tre Lawrence on April 18th, 2014 [ permalink ] | Read more »
My Incredible Body - A Kid's App to...
My Incredible Body - A Kid's App to Learn about the Human Body 1.1.00 Device: iOS Universal Category: Education Price: $2.99, Version: 1.1.00 (iTunes) Description: Wouldn’t it be cool to look inside yourself and see what was going on... | Read more »
Trials Frontier Review
Trials Frontier Review By Carter Dotson on April 18th, 2014 Our Rating: :: A ROUGH LANDINGUniversal App - Designed for iPhone and iPad Trials Frontier finally brings the famed stunt racing franchise to mobile, but how much does its... | Read more »

Price Scanner via MacPrices.net

Deal Alert! 13-inch MacBook Pro on sale for $...
Best Buy has the 13″ 2.5GHz MacBook Pro on sale for $999.99 on their online store. Choose free shipping or free instant local store pickup (if available). Their price is $200 off MSRP. Price is valid... Read more
Free HopTo 2.2 Helps Enhance Your Productivit...
The HopTo app helps you do more on your iPad by providing more and easier adaccess to files and documents. Version 2.2 adds Egnyte and HopTo’s Mac OSX File Connector. If you already have the hopTo... Read more
National Distracted Driving Awareness Month:...
As the country recognizes National Distracted Driving Awareness Month, Sprint is reminding wireless consumers to focus on driving while behind the wheel, to not text or email while driving, and to... Read more
13-inch 2.4GHz Retina MacBook Pro available f...
Abt has the 13″ 2.4GHz 128GB Retina MacBook Pro available for $1229 including free shipping. Their price is $70 off MSRP. Read more
iMacs on sale for up to $160 off MSRP this we...
Best Buy has iMacs on sale for up to $160 off MSRP for a limited time. Choose free home shipping or free instant local store pickup (if available). Prices are valid for online orders only, in-store... Read more
iPad Airs on sale this weekend for up to $100...
Best Buy has WiFi iPad Airs on sale for $50 off MSRP and WiFi + Cellular iPad Airs on sale for $100 off MSRP on their online store for a limited time, with prices now starting at $449. Choose free... Read more
Apple restocks refurbished Mac minis starting...
The Apple Store has restocked Apple Certified Refurbished Mac minis for up to $150 off the cost of new models. Apple’s one-year warranty is included with each mini, and shipping is free: - 2.5GHz Mac... Read more
Hyundai Brings Apple CarPlay To The 2015 Sona...
Hyundai Motor America has announced it will bring Apple CarPlay functionality to the 2015 Sonata. CarPlay is pitched as a smarter, safer and easier way to use iPhone in the car and gives iPhone users... Read more
Updated iPads Coming Sooner Than We Had Thoug...
MacRumors, cites KGI securities analyst Ming Chi Kuo, well-respected as an Apple product prognisticator, saying that Apple will introduce an upgraded iPad Air and iPad mini in 2014/Q3, meaning the... Read more
Toshiba Unveils New High And Low End Laptop M...
Toshiba has announced new laptop models covering both the high-end and low-end of the notebook computer spectrum. Toshiba 4K Ultra HD Laptop Toshiba’s new Satellite P55t features one of the world’s... Read more

Jobs Board

Position Opening at *Apple* - Apple (United...
…customers purchase our products, you're the one who helps them get more out of their new Apple technology. Your day in the Apple Store is filled with a range of 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
*Apple* Inc. Research Data Specialist - Appl...
…of Worldwide Market Research & Intelligence. The team is responsible for conducting Apple branded consumer market research. It is also responsible for analyzing data Read more
*Apple* Automotive Parts Department position...
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
*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.