tim/prune/data/Coordinate.java

   1 package tim.prune.data;
   2
   3 import java.text.DecimalFormat;
   4 import java.text.NumberFormat;
   5 import java.util.Locale;
   6
   7 /**
   8  * Class to represent a lat/long coordinate
   9  * and provide conversion functions
  10  */
  11 public abstract class Coordinate
  12 {
  13         public static final int NO_CARDINAL = -1;
  14         public static final int NORTH = 0;
  15         public static final int EAST = 1;
  16         public static final int SOUTH = 2;
  17         public static final int WEST = 3;
  18         private static final char[] PRINTABLE_CARDINALS = {'N', 'E', 'S', 'W'};
  19         public static final int FORMAT_DEG_MIN_SEC = 10;
  20         public static final int FORMAT_DEG_MIN = 11;
  21         public static final int FORMAT_DEG = 12;
  22         public static final int FORMAT_DEG_WITHOUT_CARDINAL = 13;
  23         public static final int FORMAT_DEG_WHOLE_MIN = 14;
  24         public static final int FORMAT_DEG_MIN_SEC_WITH_SPACES = 15;
  25         public static final int FORMAT_CARDINAL = 16;
  26         public static final int FORMAT_DECIMAL_FORCE_POINT = 17;
  27         public static final int FORMAT_NONE = 19;
  28
  29         /** Number formatter for fixed decimals with forced decimal point */
  30         private static final NumberFormat EIGHT_DP = NumberFormat.getNumberInstance(Locale.UK);
  31         // Select the UK locale for this formatter so that decimal point is always used (not comma)
  32         static {
  33                 if (EIGHT_DP instanceof DecimalFormat) ((DecimalFormat) EIGHT_DP).applyPattern("0.00000000");
  34         }
  35
  36         // Instance variables
  37         private boolean _valid = false;
  38         private boolean _cardinalGuessed = false;
  39         protected int _cardinal = NORTH;
  40         private int _degrees = 0;
  41         private int _minutes = 0;
  42         private int _seconds = 0;
  43         private int _fracs = 0;
  44         private int _fracDenom = 0;
  45         private String _originalString = null;
  46         private int _originalFormat = FORMAT_NONE;
  47         private double _asDouble = 0.0;
  48
  49
  50         /**
  51          * Constructor given String
  52          * @param inString string to parse
  53          */
  54         public Coordinate(String inString)
  55         {
  56                 _originalString = inString;
  57                 int strLen = 0;
  58                 if (inString != null)
  59                 {
  60                         inString = inString.trim();
  61                         strLen = inString.length();
  62                 }
  63                 if (strLen > 0)
  64                 {
  65                         // Check for cardinal character either at beginning or end
  66                         boolean hasCardinal = true;
  67                         _cardinal = getCardinal(inString.charAt(0), inString.charAt(strLen-1));
  68                         if (_cardinal == NO_CARDINAL) {
  69                                 hasCardinal = false;
  70                                 // use default from concrete subclass
  71                                 _cardinal = getDefaultCardinal();
  72                                 _cardinalGuessed = true;
  73                         }
  74                         else if (isJustNumber(inString)) {
  75                                 // it's just a number
  76                                 hasCardinal = false;
  77                                 _cardinalGuessed = true;
  78                         }
  79
  80                         // count numeric fields - 1=d, 2=dm, 3=dm.m/dms, 4=dms.s
  81                         int numFields = 0;
  82                         boolean inNumeric = false;
  83                         char currChar;
  84                         long[] fields = new long[4]; // needs to be long for lengthy decimals
  85                         long[] denoms = new long[4];
  86                         boolean[] otherDelims = new boolean[5]; // remember whether delimiters have non-decimal chars
  87                         try
  88                         {
  89                                 // Loop over characters in input string, populating fields array
  90                                 for (int i=0; i<strLen; i++)
  91                                 {
  92                                         currChar = inString.charAt(i);
  93                                         if (currChar >= '0' && currChar <= '9')
  94                                         {
  95                                                 if (!inNumeric)
  96                                                 {
  97                                                         inNumeric = true;
  98                                                         numFields++;
  99                                                         denoms[numFields-1] = 1;
 100                                                 }
 101                                                 if (denoms[numFields-1] < 1E18) // ignore trailing characters if too big for long
 102                                                 {
 103                                                         fields[numFields-1] = fields[numFields-1] * 10 + (currChar - '0');
 104                                                         denoms[numFields-1] *= 10;
 105                                                 }
 106                                         }
 107                                         else
 108                                         {
 109                                                 inNumeric = false;
 110                                                 // Remember delimiters
 111                                                 if (currChar != ',' && currChar != '.') {otherDelims[numFields] = true;}
 112                                         }
 113                                 }
 114                                 _valid = (numFields > 0);
 115                         }
 116                         catch (ArrayIndexOutOfBoundsException obe)
 117                         {
 118                                 // more than four fields found - unable to parse
 119                                 _valid = false;
 120                         }
 121                         // parse fields according to number found
 122                         _degrees = (int) fields[0];
 123                         _asDouble = _degrees;
 124                         _originalFormat = hasCardinal?FORMAT_DEG:FORMAT_DEG_WITHOUT_CARDINAL;
 125                         _fracDenom = 10;
 126                         if (numFields == 2)
 127                         {
 128                                 if (!otherDelims[1])
 129                                 {
 130                                         // String is just decimal degrees
 131                                         double numMins = fields[1] * 60.0 / denoms[1];
 132                                         _minutes = (int) numMins;
 133                                         double numSecs = (numMins - _minutes) * 60.0;
 134                                         _seconds = (int) numSecs;
 135                                         _fracs = (int) ((numSecs - _seconds) * 10);
 136                                         _asDouble = _degrees + 1.0 * fields[1] / denoms[1];
 137                                 }
 138                                 else
 139                                 {
 140                                         // String is degrees and minutes (due to non-decimal separator)
 141                                         _originalFormat = FORMAT_DEG_MIN;
 142                                         _minutes = (int) fields[1];
 143                                         _seconds = 0;
 144                                         _fracs = 0;
 145                                         _asDouble = 1.0 * _degrees + (_minutes / 60.0);
 146                                 }
 147                         }
 148                         // Differentiate between d-m.f and d-m-s using . or ,
 149                         else if (numFields == 3 && !otherDelims[2])
 150                         {
 151                                 // String is degrees-minutes.fractions
 152                                 _originalFormat = FORMAT_DEG_MIN;
 153                                 _minutes = (int) fields[1];
 154                                 double numSecs = fields[2] * 60.0 / denoms[2];
 155                                 _seconds = (int) numSecs;
 156                                 _fracs = (int) ((numSecs - _seconds) * 10);
 157                                 _asDouble = 1.0 * _degrees + (_minutes / 60.0) + (numSecs / 3600.0);
 158                         }
 159                         else if (numFields == 4 || numFields == 3)
 160                         {
 161                                 // String is degrees-minutes-seconds.fractions
 162                                 _originalFormat = FORMAT_DEG_MIN_SEC;
 163                                 _minutes = (int) fields[1];
 164                                 _seconds = (int) fields[2];
 165                                 _fracs = (int) fields[3];
 166                                 _fracDenom = (int) denoms[3];
 167                                 if (_fracDenom < 1) {_fracDenom = 1;}
 168                                 _asDouble = 1.0 * _degrees + (_minutes / 60.0) + (_seconds / 3600.0) + (_fracs / 3600.0 / _fracDenom);
 169                         }
 170                         if (_cardinal == WEST || _cardinal == SOUTH || inString.charAt(0) == '-')
 171                                 _asDouble = -_asDouble;
 172                         // validate fields
 173                         _valid = _valid && (_degrees <= getMaxDegrees() && _minutes < 60 && _seconds < 60 && _fracs < _fracDenom);
 174                 }
 175                 else _valid = false;
 176         }
 177
 178
 179         /**
 180          * Get the cardinal from the given character
 181          * @param inFirstChar first character from file
 182          * @param inLastChar last character from file
 183          */
 184         protected int getCardinal(char inFirstChar, char inLastChar)
 185         {
 186                 // Try leading character first
 187                 int cardinal = getCardinal(inFirstChar);
 188                 // if not there, try trailing character
 189                 if (cardinal == NO_CARDINAL) {
 190                         cardinal = getCardinal(inLastChar);
 191                 }
 192                 return cardinal;
 193         }
 194
 195         /**
 196          * @return true if cardinal was guessed, false if parsed
 197          */
 198         public boolean getCardinalGuessed() {
 199                 return _cardinalGuessed;
 200         }
 201
 202         /**
 203          * Get the cardinal from the given character
 204          * @param inChar character from file
 205          */
 206         protected abstract int getCardinal(char inChar);
 207
 208         /**
 209          * @return the default cardinal for the subclass
 210          */
 211         protected abstract int getDefaultCardinal();
 212
 213         /**
 214          * @return the maximum degree range for this coordinate
 215          */
 216         protected abstract int getMaxDegrees();
 217
 218
 219         /**
 220          * Constructor
 221          * @param inValue value of coordinate
 222          * @param inFormat format to use
 223          * @param inCardinal cardinal
 224          */
 225         protected Coordinate(double inValue, int inFormat, int inCardinal)
 226         {
 227                 _asDouble = inValue;
 228                 // Calculate degrees, minutes, seconds
 229                 _degrees = (int) Math.abs(inValue);
 230                 double numMins = (Math.abs(_asDouble)-_degrees) * 60.0;
 231                 _minutes = (int) numMins;
 232                 double numSecs = (numMins - _minutes) * 60.0;
 233                 _seconds = (int) numSecs;
 234                 _fracs = (int) ((numSecs - _seconds) * 10);
 235                 _fracDenom = 10; // fixed for now
 236                 // Make a string to display on screen
 237                 _cardinal = inCardinal;
 238                 _originalFormat = FORMAT_NONE;
 239                 if (inFormat == FORMAT_NONE) inFormat = FORMAT_DEG_WITHOUT_CARDINAL;
 240                 _originalString = output(inFormat);
 241                 _originalFormat = inFormat;
 242                 _valid = true;
 243         }
 244
 245
 246         /**
 247          * @return coordinate as a double
 248          */
 249         public double getDouble()
 250         {
 251                 return _asDouble;
 252         }
 253
 254         /**
 255          * @return true if Coordinate is valid
 256          */
 257         public boolean isValid()
 258         {
 259                 return _valid;
 260         }
 261
 262         /**
 263          * Compares two Coordinates for equality
 264          * @param inOther other Coordinate object with which to compare
 265          * @return true if the two objects are equal
 266          */
 267         public boolean equals(Coordinate inOther)
 268         {
 269                 return (_asDouble == inOther._asDouble);
 270         }
 271
 272
 273         /**
 274          * Output the Coordinate in the given format
 275          * @param inFormat format to use, eg FORMAT_DEG_MIN_SEC
 276          * @return String for output
 277          */
 278         public String output(int inFormat)
 279         {
 280                 String answer = _originalString;
 281                 if (inFormat != FORMAT_NONE && inFormat != _originalFormat)
 282                 {
 283                         // TODO: allow specification of precision for output of d-m and d
 284                         // format as specified
 285                         switch (inFormat)
 286                         {
 287                                 case FORMAT_DEG_MIN_SEC:
 288                                 {
 289                                         StringBuffer buffer = new StringBuffer();
 290                                         buffer.append(PRINTABLE_CARDINALS[_cardinal])
 291                                                 .append(threeDigitString(_degrees)).append('\u00B0')
 292                                                 .append(twoDigitString(_minutes)).append('\'')
 293                                                 .append(twoDigitString(_seconds)).append('.')
 294                                                 .append(formatFraction(_fracs, _fracDenom));
 295                                         answer = buffer.toString();
 296                                         break;
 297                                 }
 298                                 case FORMAT_DEG_MIN:
 299                                 {
 300                                         answer = "" + PRINTABLE_CARDINALS[_cardinal] + threeDigitString(_degrees) + "\u00B0"
 301                                                 + (_minutes + _seconds / 60.0 + _fracs / 60.0 / _fracDenom) + "'";
 302                                         break;
 303                                 }
 304                                 case FORMAT_DEG_WHOLE_MIN:
 305                                 {
 306                                         int deg = _degrees;
 307                                         int min = (int) Math.floor(_minutes + _seconds / 60.0 + _fracs / 60.0 / _fracDenom + 0.5);
 308                                         if (min == 60) {
 309                                                 min = 0; deg++;
 310                                         }
 311                                         answer = "" + PRINTABLE_CARDINALS[_cardinal] + threeDigitString(deg) + "\u00B0" + min + "'";
 312                                         break;
 313                                 }
 314                                 case FORMAT_DEG:
 315                                 case FORMAT_DEG_WITHOUT_CARDINAL:
 316                                 {
 317                                         answer = (_asDouble<0.0?"-":"")
 318                                                 + (_degrees + _minutes / 60.0 + _seconds / 3600.0 + _fracs / 3600.0 / _fracDenom);
 319                                         break;
 320                                 }
 321                                 case FORMAT_DECIMAL_FORCE_POINT:
 322                                 {
 323                                         // Forcing a decimal point instead of system-dependent commas etc
 324                                         if (_originalFormat != FORMAT_DEG_WITHOUT_CARDINAL || answer.indexOf('.') < 0) {
 325                                                 answer = EIGHT_DP.format(_asDouble);
 326                                         }
 327                                         break;
 328                                 }
 329                                 case FORMAT_DEG_MIN_SEC_WITH_SPACES:
 330                                 {
 331                                         // Note: cardinal not needed as this format is only for exif, which has cardinal separately
 332                                         answer = "" + _degrees + " " + _minutes + " " + _seconds + "." + formatFraction(_fracs, _fracDenom);
 333                                         break;
 334                                 }
 335                                 case FORMAT_CARDINAL:
 336                                 {
 337                                         answer = "" + PRINTABLE_CARDINALS[_cardinal];
 338                                         break;
 339                                 }
 340                         }
 341                 }
 342                 return answer;
 343         }
 344
 345         /**
 346          * Format the fraction part of seconds value
 347          * @param inFrac fractional part eg 123
 348          * @param inDenom denominator of fraction eg 10000
 349          * @return String describing fraction, in this case 0123
 350          */
 351         private static final String formatFraction(int inFrac, int inDenom)
 352         {
 353                 if (inDenom <= 1 || inFrac == 0) {return "" + inFrac;}
 354                 String denomString = "" + inDenom;
 355                 int reqdLen = denomString.length() - 1;
 356                 String result = denomString + inFrac;
 357                 int resultLen = result.length();
 358                 return result.substring(resultLen - reqdLen);
 359         }
 360
 361
 362         /**
 363          * Format an integer to a two-digit String
 364          * @param inNumber number to format
 365          * @return two-character String
 366          */
 367         private static String twoDigitString(int inNumber)
 368         {
 369                 if (inNumber <= 0) return "00";
 370                 if (inNumber < 10) return "0" + inNumber;
 371                 if (inNumber < 100) return "" + inNumber;
 372                 return "" + (inNumber % 100);
 373         }
 374
 375
 376         /**
 377          * Format an integer to a three-digit String for degrees
 378          * @param inNumber number to format
 379          * @return three-character String
 380          */
 381         private static String threeDigitString(int inNumber)
 382         {
 383                 if (inNumber <= 0) return "000";
 384                 if (inNumber < 10) return "00" + inNumber;
 385                 if (inNumber < 100) return "0" + inNumber;
 386                 return "" + (inNumber % 1000);
 387         }
 388
 389
 390         /**
 391          * Create a new Coordinate between two others
 392          * @param inStart start coordinate
 393          * @param inEnd end coordinate
 394          * @param inIndex index of point
 395          * @param inNumPoints number of points to interpolate
 396          * @return new Coordinate object
 397          */
 398         public static Coordinate interpolate(Coordinate inStart, Coordinate inEnd,
 399                 int inIndex, int inNumPoints)
 400         {
 401                 return interpolate(inStart, inEnd, 1.0 * (inIndex+1) / (inNumPoints + 1));
 402         }
 403
 404
 405         /**
 406          * Create a new Coordinate between two others
 407          * @param inStart start coordinate
 408          * @param inEnd end coordinate
 409          * @param inFraction fraction from start to end
 410          * @return new Coordinate object
 411          */
 412         public static Coordinate interpolate(Coordinate inStart, Coordinate inEnd,
 413                 double inFraction)
 414         {
 415                 double startValue = inStart.getDouble();
 416                 double endValue = inEnd.getDouble();
 417                 double newValue = startValue + (endValue - startValue) * inFraction;
 418                 Coordinate answer = inStart.makeNew(newValue, inStart._originalFormat);
 419                 return answer;
 420         }
 421
 422
 423         /**
 424          * Make a new Coordinate according to subclass
 425          * @param inValue double value
 426          * @param inFormat format to use
 427          * @return object of Coordinate subclass
 428          */
 429         protected abstract Coordinate makeNew(double inValue, int inFormat);
 430
 431         /**
 432          * Try to parse the given string
 433          * @param inString string to check
 434          * @return true if it can be parsed as a number
 435          */
 436         private static boolean isJustNumber(String inString)
 437         {
 438                 boolean justNum = false;
 439                 try {
 440                         double x = Double.parseDouble(inString);
 441                         justNum = (x >= -180.0 && x <= 360.0);
 442                 }
 443                 catch (NumberFormatException nfe) {} // flag remains false
 444                 return justNum;
 445         }
 446
 447         /**
 448          * Create a String representation for debug
 449          * @return String describing coordinate value
 450          */
 451         public String toString()
 452         {
 453                 return "Coord: " + _cardinal + " (" + _degrees + ") (" + _minutes + ") (" + _seconds + "."
 454                         + formatFraction(_fracs, _fracDenom) + ") = " + _asDouble;
 455         }
 456 }