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

Firefox 37.0 - Fast, safe Web browser. (...
Firefox offers a fast, safe Web browsing experience. Browse quickly, securely, and effortlessly. With its industry-leading features, Firefox is the choice of Web development professionals and casual... Read more
Arq 4.11 - Online backup to Google Drive...
Arq is super-easy online backup for the Mac. Back up to your own Google Drive storage (15GB free storage), your own Amazon Glacier ($.01/GB per month storage) or S3, or any SFTP server. Arq backs up... Read more
MacFamilyTree 7.3.4 - Create and explore...
MacFamilyTree gives genealogy a facelift: it's modern, interactive, incredibly fast, and easy to use. We're convinced that generations of chroniclers would have loved to trade in their genealogy... Read more
Yummy FTP 1.10.2 - FTP/SFTP/FTPS client...
Yummy FTP is an FTP + SFTP + FTPS file transfer client which focuses on speed, reliability and productivity. Whether you need to transfer a few files or a few thousand, schedule automatic backups, or... Read more
VueScan 9.5.08 - Scanner software with a...
VueScan is a scanning program that works with most high-quality flatbed and film scanners to produce scans that have excellent color fidelity and color balance. VueScan is easy to use, and has... Read more
Iridient Developer 3.0.1 - Powerful imag...
Iridient Developer (was RAW Developer) is a powerful image conversion application designed specifically for OS X. Iridient Developer gives advanced photographers total control over every aspect of... Read more
Air Video Server HD 2.1.0 - Stream video...
Air Video Server HD streams videos instantly from your computer on your iPhone, iPad, iPod touch or Apple TV. No need to worry about converting or transferring files. We took everything that was... Read more
Duplicate Annihilator 5.7.5 - Find and d...
Duplicate Annihilator takes on the time-consuming task of comparing the images in your iPhoto library using effective algorithms to make sure that no duplicate escapes. Duplicate Annihilator... Read more
BusyContacts 1.0.2 - Fast, efficient con...
BusyContacts is a contact manager for OS X that makes creating, finding, and managing contacts faster and more efficient. It brings to contact management the same power, flexibility, and sharing... Read more
Capture One Pro 8.2.0.82 - RAW workflow...
Capture One Pro 8 is a professional RAW converter offering you ultimate image quality with accurate colors and incredible detail from more than 300 high-end cameras -- straight out of the box. It... Read more

2K Announces WWE 2K, Mobile's First...
It seems like this month has been pretty big for wrestling. First Wrestlemania, then 2K has announces that they're releasing  WWE 2K for iOS. It's a simulation-based WWE game where you'll get to play with several WWE superstars such as John Cena, ... | Read more »
How the Apple Watch Could Change the Fac...
The Apple Watch is still a ways out, but my previous musings on the wearable’s various features got me thinking: what might it be like a year after launch? Two years? Five years? What if it becomes a symbiotic part of the iOS framework to the point... | Read more »
Pie In The Sky: A Pizza Odyssey (Games)
Pie In The Sky: A Pizza Odyssey 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: A game about delivering pizza. In space. | Read more »
Chosen Gives Hopeful Singers, Songwriter...
If YouTube videos and reality TV shows like The Voice have taught us one thing, it’s that there are a lot of people out there who are anxious to show the world their talents. And if they’ve taught us a second thing, it’s that there’s an almost... | Read more »
Android's Popular OfficeSuite Now A...
Once only available for Android devices, OfficeSuite has finally landed on the app store. The Mobile Systems app lets you view, edit, create, and share Word, Excel, and PowerPoint documents as well as convert them to/from PDFs. It's touted as being... | Read more »
Warhammer: Arcane Magic is Coming Soon,...
Turbo Tape Games has announced that they're joining forces with Games Workshop to bring the turn-based strategy board game, Warhammer: Arcane Magic, to life on the iOS. | Read more »
Fast & Furious: Legacy's Creati...
| Read more »
N-Fusion and 505's Ember is Totally...
| Read more »
These are All the Apple Watch Apps and G...
The Apple Watch is less than a month from hitting store shelves, and once you get your hands on it you're probably going to want some apps and games to install. Fear not! We've compiled a list of all the Apple Watch apps and games we've been able to... | Read more »
Appy to Have Known You - Lee Hamlet Look...
Being at 148Apps these past 2 years has been an awesome experience that has taught me a great deal, and working with such a great team has been a privilege. Thank you to Rob Rich, and to both Rob LeFebvre and Jeff Scott before him, for helping me... | Read more »

Price Scanner via MacPrices.net

Adobe Brings Powerful Layout-Design Capabilit...
Adobe today announced the availability of Adobe Comp CC, a free iPad app that enables rapid creation of layout concepts for mobile, Web and print projects. With Comp CC, designers can rough out and... Read more
Apple offering refurbished 27-inch 5K iMacs f...
The Apple Store is offering Apple Certified Refurbished 27″ 3.5GHz 5K iMacs for $2119 including free shipping. Their price is $380 off the price of new models, and it’s the lowest price available for... Read more
16GB iPad mini on sale for $199, save $50
Walmart has 16GB iPad minis (1st generation) available for $199.99 on their online store, including free shipping. Their price is $50 off MSRP. Online orders only. Read more
New 128GB MacBook Airs on sale for $50 off MS...
 B&H Photo has 128GB 11″ and 13″ 2015 MacBook Airs on sale today for $50 off MSRP including free shipping plus NY sales tax only: - 11″ 1.6GHz/128GB MacBook Air (Model #MJVM2LL/A): $849 $50 off... Read more
13-inch 2.6GHz Retina MacBook Pro (refurbishe...
The Apple Store has Apple Certified Refurbished 13″ 2.6GHz/128GB Retina MacBook Pros available for $979 including free shipping. Original MSRP for this model was $1299. Read more
Save up to $600 with Apple refurbished Mac Pr...
The Apple Store is offering Apple Certified Refurbished Mac Pros for up to $600 off the cost of new models. An Apple one-year warranty is included with each Mac Pro, and shipping is free. The... Read more
Samsung Galaxy S 6 and Galaxy S 6 edge U.S. P...
Samsung Electronics America, Inc. has announced the Galaxy S 6 and Galaxy S 6 edge will be available in the U.S. beginning April 10, with pre-orders being accepted now. “We have completely reimagined... Read more
13-inch 2.5GHz MacBook Pro (refurbished) avai...
The Apple Store has Apple Certified Refurbished 13″ 2.5GHz MacBook Pros available for $829, or $270 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free: - 13″ 2.... Read more
Save up to $80 on iPad Air 2s, NY tax only, f...
 B&H Photo has iPad Air 2s on sale for $80 off MSRP including free shipping plus NY sales tax only: - 16GB iPad Air 2 WiFi: $469.99 $30 off - 64GB iPad Air 2 WiFi: $549.99 $50 off - 128GB iPad... Read more
iMacs on sale for up to $205 off MSRP
B&H Photo has 21″ and 27″ iMacs on sale for up to $205 off MSRP including free shipping plus NY sales tax only: - 21″ 1.4GHz iMac: $1019 $80 off - 21″ 2.7GHz iMac: $1189 $110 off - 21″ 2.9GHz... Read more

Jobs Board

DevOps Software Engineer - *Apple* Pay, iOS...
**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
*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. Technical Services Consultant, *Apple*...
**Job Summary** Apple Professional Services (APS) has an opening for a senior technical position that contributes to Apple 's efforts for strategic and transactional Read more
Lead *Apple* Solutions Consultant - Retail...
**Job Summary** Job Summary The Lead ASC is an Apple employee who serves as the Apple business manager and influencer in a hyper-business critical Reseller's store Read more
*Apple* Pay - Site Reliability Engineer - 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
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.