Determining when an adjustment layer holds information.

Question

Is it possible using javascript to determine when an adjustment layer holds information? I'll go into some detail as to what I mean.
I run a combination script/actions to set up a bunch of layers based on what I'm doing. Not all layers will get used in any given image. For example, when I'm retouching a model's photo, I run one that sets up a bunch of adjustment layers to enhance the color in the models eyes, or to change the color depending on what I'm doing. This sets up seven layers, each for a different color, then a few for highlights and/or catchlights. I may use between 0 and 3 of these layers. Each adjustment layer has an inverse mask (black) which I paint white in the areas I want to enhance.
Now, is there an easy way to determine which of these masks are pure black and which have been painted onto? Also, is there an easy way to determine on an adjustment layer such as curves, levels, hue/saturation, etc. whether any adjustments have been made or if they are still in default? I'm guessing the best way would be to first check the mask to see if it's not all black and if it isn't, then check for adjustments.

Answer 1

I was not really happy with the way I was testing for default settings. I was afraid that the simple replace text I was using might fail in some cases. It turns out that I was right. So here is a new set of functions. These I feel good about using.
All of the functions need this CRC code.
  JavaScript source code        March 10, 2006
  Copyright (c) 2003-2006 Scandinavian Digital Systems AB
  Internet: http://www.digsys.se
  Freeware: The source code and its methods and algorithms may be
            used as desired without restrictions.
  CRC-32 (as it is in ZMODEM) in table form
  Copyright (C) 1986 Gary S. Brown. You may use this program, or
  code or tables extracted from it, as desired without restriction.
  Modified by Anders Danielsson, February 5, 1989 and March 10, 2006.
  This is also known as FCS-32 (as it is in PPP), described in
  RFC-1662 by William Allen Simpson, see RFC-1662 for references.
var Crc32Tab = new Array( /* CRC polynomial 0xEDB88320 */
  C/C++ language:
  unsigned long Crc32Tab[] = {...};
0x00000000,0x77073096,0xEE0E612C,0x990951BA,0x076DC419,0x706AF48F,0xE963A535,0x9E6495A3,
0x0EDB8832,0x79DCB8A4,0xE0D5E91E,0x97D2D988,0x09B64C2B,0x7EB17CBD,0xE7B82D07,0x90BF1D91,
0x1DB71064,0x6AB020F2,0xF3B97148,0x84BE41DE,0x1ADAD47D,0x6DDDE4EB,0xF4D4B551,0x83D385C7,
0x136C9856,0x646BA8C0,0xFD62F97A,0x8A65C9EC,0x14015C4F,0x63066CD9,0xFA0F3D63,0x8D080DF5,
0x3B6E20C8,0x4C69105E,0xD56041E4,0xA2677172,0x3C03E4D1,0x4B04D447,0xD20D85FD,0xA50AB56B,
0x35B5A8FA,0x42B2986C,0xDBBBC9D6,0xACBCF940,0x32D86CE3,0x45DF5C75,0xDCD60DCF,0xABD13D59,
0x26D930AC,0x51DE003A,0xC8D75180,0xBFD06116,0x21B4F4B5,0x56B3C423,0xCFBA9599,0xB8BDA50F,
0x2802B89E,0x5F058808,0xC60CD9B2,0xB10BE924,0x2F6F7C87,0x58684C11,0xC1611DAB,0xB6662D3D,
0x76DC4190,0x01DB7106,0x98D220BC,0xEFD5102A,0x71B18589,0x06B6B51F,0x9FBFE4A5,0xE8B8D433,
0x7807C9A2,0x0F00F934,0x9609A88E,0xE10E9818,0x7F6A0DBB,0x086D3D2D,0x91646C97,0xE6635C01,
0x6B6B51F4,0x1C6C6162,0x856530D8,0xF262004E,0x6C0695ED,0x1B01A57B,0x8208F4C1,0xF50FC457,
0x65B0D9C6,0x12B7E950,0x8BBEB8EA,0xFCB9887C,0x62DD1DDF,0x15DA2D49,0x8CD37CF3,0xFBD44C65,
0x4DB26158,0x3AB551CE,0xA3BC0074,0xD4BB30E2,0x4ADFA541,0x3DD895D7,0xA4D1C46D,0xD3D6F4FB,
0x4369E96A,0x346ED9FC,0xAD678846,0xDA60B8D0,0x44042D73,0x33031DE5,0xAA0A4C5F,0xDD0D7CC9,
0x5005713C,0x270241AA,0xBE0B1010,0xC90C2086,0x5768B525,0x206F85B3,0xB966D409,0xCE61E49F,
0x5EDEF90E,0x29D9C998,0xB0D09822,0xC7D7A8B4,0x59B33D17,0x2EB40D81,0xB7BD5C3B,0xC0BA6CAD,
0xEDB88320,0x9ABFB3B6,0x03B6E20C,0x74B1D29A,0xEAD54739,0x9DD277AF,0x04DB2615,0x73DC1683,
0xE3630B12,0x94643B84,0x0D6D6A3E,0x7A6A5AA8,0xE40ECF0B,0x9309FF9D,0x0A00AE27,0x7D079EB1,
0xF00F9344,0x8708A3D2,0x1E01F268,0x6906C2FE,0xF762575D,0x806567CB,0x196C3671,0x6E6B06E7,
0xFED41B76,0x89D32BE0,0x10DA7A5A,0x67DD4ACC,0xF9B9DF6F,0x8EBEEFF9,0x17B7BE43,0x60B08ED5,
0xD6D6A3E8,0xA1D1937E,0x38D8C2C4,0x4FDFF252,0xD1BB67F1,0xA6BC5767,0x3FB506DD,0x48B2364B,
0xD80D2BDA,0xAF0A1B4C,0x36034AF6,0x41047A60,0xDF60EFC3,0xA867DF55,0x316E8EEF,0x4669BE79,
0xCB61B38C,0xBC66831A,0x256FD2A0,0x5268E236,0xCC0C7795,0xBB0B4703,0x220216B9,0x5505262F,
0xC5BA3BBE,0xB2BD0B28,0x2BB45A92,0x5CB36A04,0xC2D7FFA7,0xB5D0CF31,0x2CD99E8B,0x5BDEAE1D,
0x9B64C2B0,0xEC63F226,0x756AA39C,0x026D930A,0x9C0906A9,0xEB0E363F,0x72076785,0x05005713,
0x95BF4A82,0xE2B87A14,0x7BB12BAE,0x0CB61B38,0x92D28E9B,0xE5D5BE0D,0x7CDCEFB7,0x0BDBDF21,
0x86D3D2D4,0xF1D4E242,0x68DDB3F8,0x1FDA836E,0x81BE16CD,0xF6B9265B,0x6FB077E1,0x18B74777,
0x88085AE6,0xFF0F6A70,0x66063BCA,0x11010B5C,0x8F659EFF,0xF862AE69,0x616BFFD3,0x166CCF45,
0xA00AE278,0xD70DD2EE,0x4E048354,0x3903B3C2,0xA7672661,0xD06016F7,0x4969474D,0x3E6E77DB,
0xAED16A4A,0xD9D65ADC,0x40DF0B66,0x37D83BF0,0xA9BCAE53,0xDEBB9EC5,0x47B2CF7F,0x30B5FFE9,
0xBDBDF21C,0xCABAC28A,0x53B39330,0x24B4A3A6,0xBAD03605,0xCDD70693,0x54DE5729,0x23D967BF,
0xB3667A2E,0xC4614AB8,0x5D681B02,0x2A6F2B94,0xB40BBE37,0xC30C8EA1,0x5A05DF1B,0x2D02EF8D);
function Crc32Add(crc,c)
  'crc' should be initialized to 0xFFFFFFFF and after the computation it should be
  complemented (inverted).
  CRC-32 is also known as FCS-32.
  If the FCS-32 is calculated over the data and over the complemented FCS-32, the
  result will always be 0xDEBB20E3 (without the complementation).
  return Crc32Tab[(crc^c)&0xFF]^((crc>>8)&0xFFFFFF);
  C/C++ language:
  inline unsigned long Crc32Add(unsigned long crc, unsigned char c)
    return Crc32Tab[(unsigned char)crc^c]^(crc>>8);
  Application functions that calculates CRC of a string
function Crc32Str(str)
  var n;
  var len=str.length;
  var crc;
  crc=0xFFFFFFFF;
  for (n=0; n<len; n++)
    crc=Crc32Add(crc,str.charCodeAt(n));
  return crc^0xFFFFFFFF;
  Hex convert functions
function Hex32(val)
  Convert value as 32-bit unsigned integer to 8 digit hexadecimal number prefixed with "0x".
  var n;
  var str1;
  var str2;
  n=val&0xFFFF;
  str1=n.toString(16).toUpperCase();
  while (str1.length<4)
    str1="0"+str1;
  n=(val>>>16)&0xFFFF;
  str2=n.toString(16).toUpperCase();
  while (str2.length<4)
    str2="0"+str2;
  return "0x"+str2+str1;
isDefaultHueSatAdjustment();
function isDefaultHueSatAdjustment(){
     if(app.activeDocument.activeLayer.kind != LayerKind.HUESATURATION ) return;
     var ref = new ActionReference();
     ref.putEnumerated( charIDToTypeID("Lyr "), charIDToTypeID("Ordn"), charIDToTypeID("Trgt") );
     var desc = executeActionGet(ref).getList(stringIDToTypeID('adjustment')).getObjectValue(0);
     var rawData = desc.getData(stringIDToTypeID('legacyContentData'));
     var str = Hex32(Crc32Str(rawData));
     if( str == '0xB83ED6B1' ) return true;
     return false;
isDefaultColorBalanceAdjustment();
function isDefaultColorBalanceAdjustment(){
     if(app.activeDocument.activeLayer.kind != LayerKind.COLORBALANCE ) return;
     var ref = new ActionReference();
     ref.putEnumerated( charIDToTypeID("Lyr "), charIDToTypeID("Ordn"), charIDToTypeID("Trgt") );
     var desc = executeActionGet(ref).getList(stringIDToTypeID('adjustment')).getObjectValue(0);
     var rawData = desc.getData(stringIDToTypeID('legacyContentData'));
     var str = Hex32(Crc32Str(rawData));
     if( str == '0x16CEAACC' ) return true;
     return false;
isDefaultCurvesAdjustment();
function isDefaultCurvesAdjustment(){
     if(app.activeDocument.activeLayer.kind !=  LayerKind.CURVES ) return;
     var ref = new ActionReference();
     ref.putEnumerated( charIDToTypeID("Lyr "), charIDToTypeID("Ordn"), charIDToTypeID("Trgt") );
     var desc = executeActionGet(ref).getList(stringIDToTypeID('adjustment')).getObjectValue(0);
     var rawData = desc.getData(stringIDToTypeID('legacyContentData'));
     var str = Hex32(Crc32Str(rawData));
     if( str == '0xF5315AF8' ) return true;
     return false;
isDefaultLevelsAdjustment();
function isDefaultLevelsAdjustment(){
     if(app.activeDocument.activeLayer.kind != LayerKind.LEVELS ) return;
     var ref = new ActionReference();
     ref.putEnumerated( charIDToTypeID("Lyr "), charIDToTypeID("Ordn"), charIDToTypeID("Trgt") );
     var desc = executeActionGet(ref).getList(stringIDToTypeID('adjustment')).getObjectValue(0);
     var rawData = desc.getData(stringIDToTypeID('legacyContentData'));
     var str = Hex32(Crc32Str(rawData));
     if( str == '0x02A5FFD5' ) return true;
     return false;
isDefaultBWAdjustment();
function isDefaultBWAdjustment(){
     if(app.activeDocument.activeLayer.kind != LayerKind.BLACKANDWHITE ) return;
     var ref = new ActionReference();
     ref.putEnumerated( charIDToTypeID("Lyr "), charIDToTypeID("Ordn"), charIDToTypeID("Trgt") );
     var desc = executeActionGet(ref).getList(stringIDToTypeID('adjustment')).getObjectValue(0);
     var rawData = desc.getData(stringIDToTypeID('legacyContentData'));
     var str = Hex32(Crc32Str(rawData));
     if( str == '0x8BE5167D' ) return true;
     return false;