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         /** Number formatter for fixed decimals with forced decimal point */
  36         private static final NumberFormat FIVE_DP = NumberFormat.getNumberInstance(Locale.UK);
  37         static {
  38                 if (FIVE_DP instanceof DecimalFormat) ((DecimalFormat) FIVE_DP).applyPattern("0.00000");
  39         }
  40
  41         // Instance variables
  42         private boolean _valid = false;
  43         private boolean _cardinalGuessed = false;
  44         protected int _cardinal = NORTH;
  45         private int _degrees = 0;
  46         private int _minutes = 0;
  47         private int _seconds = 0;
  48         private int _fracs = 0;
  49         private int _fracDenom = 0;
  50         private String _originalString = null;
  51         private int _originalFormat = FORMAT_NONE;
  52         private double _asDouble = 0.0;
  53
  54
  55         /**
  56          * Constructor given String
  57          * @param inString string to parse
  58          */
  59         public Coordinate(String inString)
  60         {
  61                 _originalString = inString;
  62                 int strLen = 0;
  63                 if (inString != null)
  64                 {
  65                         inString = inString.trim();
  66                         strLen = inString.length();
  67                 }
  68                 if (strLen > 0)
  69                 {
  70                         // Check for cardinal character either at beginning or end
  71                         boolean hasCardinal = true;
  72                         _cardinal = getCardinal(inString.charAt(0), inString.charAt(strLen-1));
  73                         if (_cardinal == NO_CARDINAL) {
  74                                 hasCardinal = false;
  75                                 // use default from concrete subclass
  76                                 _cardinal = getDefaultCardinal();
  77                                 _cardinalGuessed = true;
  78                         }
  79                         else if (isJustNumber(inString)) {
  80                                 // it's just a number
  81                                 hasCardinal = false;
  82                                 _cardinalGuessed = true;
  83                         }
  84
  85                         // count numeric fields - 1=d, 2=dm, 3=dm.m/dms, 4=dms.s
  86                         int numFields = 0;
  87                         boolean isNumeric = false;
  88                         char currChar;
  89                         long[] fields = new long[4]; // needs to be long for lengthy decimals
  90                         long[] denoms = new long[4];
  91                         boolean[] otherDelims = new boolean[5]; // remember whether delimiters have non-decimal chars
  92                         try
  93                         {
  94                                 // Loop over characters in input string, populating fields array
  95                                 for (int i=0; i<strLen; i++)
  96                                 {
  97                                         currChar = inString.charAt(i);
  98                                         if (currChar >= '0' && currChar <= '9')
  99                                         {
 100                                                 if (!isNumeric)
 101                                                 {
 102                                                         isNumeric = true;
 103                                                         numFields++;
 104                                                         denoms[numFields-1] = 1;
 105                                                 }
 106                                                 if (denoms[numFields-1] < 1E18) // ignore trailing characters if too big for long
 107                                                 {
 108                                                         fields[numFields-1] = fields[numFields-1] * 10 + (currChar - '0');
 109                                                         denoms[numFields-1] *= 10;
 110                                                 }
 111                                         }
 112                                         else
 113                                         {
 114                                                 isNumeric = false;
 115                                                 // Remember delimiters
 116                                                 if (currChar != ',' && currChar != '.') {otherDelims[numFields] = true;}
 117                                         }
 118                                 }
 119                                 _valid = (numFields > 0);
 120                         }
 121                         catch (ArrayIndexOutOfBoundsException obe)
 122                         {
 123                                 // more than four fields found - unable to parse
 124                                 _valid = false;
 125                         }
 126                         // parse fields according to number found
 127                         _degrees = (int) fields[0];
 128                         _asDouble = _degrees;
 129                         _originalFormat = hasCardinal?FORMAT_DEG:FORMAT_DEG_WITHOUT_CARDINAL;
 130                         _fracDenom = 10;
 131                         if (numFields == 2)
 132                         {
 133                                 if (!otherDelims[1])
 134                                 {
 135                                         // String is just decimal degrees
 136                                         double numMins = fields[1] * 60.0 / denoms[1];
 137                                         _minutes = (int) numMins;
 138                                         double numSecs = (numMins - _minutes) * 60.0;
 139                                         _seconds = (int) numSecs;
 140                                         _fracs = (int) ((numSecs - _seconds) * 10);
 141                                         _asDouble = _degrees + 1.0 * fields[1] / denoms[1];
 142                                 }
 143                                 else
 144                                 {
 145                                         // String is degrees and minutes (due to non-decimal separator)
 146                                         _originalFormat = FORMAT_DEG_MIN;
 147                                         _minutes = (int) fields[1];
 148                                         _seconds = 0;
 149                                         _fracs = 0;
 150                                         _asDouble = 1.0 * _degrees + (_minutes / 60.0);
 151                                 }
 152                         }
 153                         // Differentiate between d-m.f and d-m-s using . or ,
 154                         else if (numFields == 3 && !otherDelims[2])
 155                         {
 156                                 // String is degrees-minutes.fractions
 157                                 _originalFormat = FORMAT_DEG_MIN;
 158                                 _minutes = (int) fields[1];
 159                                 double numSecs = fields[2] * 60.0 / denoms[2];
 160                                 _seconds = (int) numSecs;
 161                                 _fracs = (int) ((numSecs - _seconds) * 10);
 162                                 _asDouble = 1.0 * _degrees + (_minutes / 60.0) + (numSecs / 3600.0);
 163                         }
 164                         else if (numFields == 4 || numFields == 3)
 165                         {
 166                                 // String is degrees-minutes-seconds.fractions
 167                                 _originalFormat = FORMAT_DEG_MIN_SEC;
 168                                 _minutes = (int) fields[1];
 169                                 _seconds = (int) fields[2];
 170                                 _fracs = (int) fields[3];
 171                                 _fracDenom = (int) denoms[3];
 172                                 if (_fracDenom < 1) {_fracDenom = 1;}
 173                                 _asDouble = 1.0 * _degrees + (_minutes / 60.0) + (_seconds / 3600.0) + (_fracs / 3600.0 / _fracDenom);
 174                         }
 175                         if (_cardinal == WEST || _cardinal == SOUTH || inString.charAt(0) == '-')
 176                                 _asDouble = -_asDouble;
 177                         // validate fields
 178                         _valid = _valid && (_degrees <= getMaxDegrees() && _minutes < 60 && _seconds < 60 && _fracs < _fracDenom)
 179                                 && Math.abs(_asDouble) <= getMaxDegrees();
 180                 }
 181                 else _valid = false;
 182         }
 183
 184
 185         /**
 186          * Get the cardinal from the given character
 187          * @param inFirstChar first character from file
 188          * @param inLastChar last character from file
 189          */
 190         protected int getCardinal(char inFirstChar, char inLastChar)
 191         {
 192                 // Try leading character first
 193                 int cardinal = getCardinal(inFirstChar);
 194                 // if not there, try trailing character
 195                 if (cardinal == NO_CARDINAL) {
 196                         cardinal = getCardinal(inLastChar);
 197                 }
 198                 return cardinal;
 199         }
 200
 201         /**
 202          * @return true if cardinal was guessed, false if parsed
 203          */
 204         public boolean getCardinalGuessed() {
 205                 return _cardinalGuessed;
 206         }
 207
 208         /**
 209          * Get the cardinal from the given character
 210          * @param inChar character from file
 211          */
 212         protected abstract int getCardinal(char inChar);
 213
 214         /**
 215          * @return the default cardinal for the subclass
 216          */
 217         protected abstract int getDefaultCardinal();
 218
 219         /**
 220          * @return the maximum degree range for this coordinate
 221          */
 222         protected abstract int getMaxDegrees();
 223
 224
 225         /**
 226          * Constructor
 227          * @param inValue value of coordinate
 228          * @param inFormat format to use
 229          * @param inCardinal cardinal
 230          */
 231         protected Coordinate(double inValue, int inFormat, int inCardinal)
 232         {
 233                 _asDouble = inValue;
 234                 // Calculate degrees, minutes, seconds
 235                 _degrees = (int) Math.abs(inValue);
 236                 double numMins = (Math.abs(_asDouble)-_degrees) * 60.0;
 237                 _minutes = (int) numMins;
 238                 double numSecs = (numMins - _minutes) * 60.0;
 239                 _seconds = (int) numSecs;
 240                 _fracs = (int) ((numSecs - _seconds) * 10);
 241                 _fracDenom = 10; // fixed for now
 242                 // Make a string to display on screen
 243                 _cardinal = inCardinal;
 244                 _originalFormat = FORMAT_NONE;
 245                 if (inFormat == FORMAT_NONE) inFormat = FORMAT_DEG_WITHOUT_CARDINAL;
 246                 _originalString = output(inFormat);
 247                 _originalFormat = inFormat;
 248                 _valid = true;
 249         }
 250
 251
 252         /**
 253          * @return coordinate as a double
 254          */
 255         public double getDouble()
 256         {
 257                 return _asDouble;
 258         }
 259
 260         /**
 261          * @return true if Coordinate is valid
 262          */
 263         public boolean isValid()
 264         {
 265                 return _valid;
 266         }
 267
 268         /**
 269          * Compares two Coordinates for equality
 270          * @param inOther other Coordinate object with which to compare
 271          * @return true if the two objects are equal
 272          */
 273         public boolean equals(Coordinate inOther)
 274         {
 275                 return (_asDouble == inOther._asDouble);
 276         }
 277
 278
 279         /**
 280          * Output the Coordinate in the given format
 281          * @param inFormat format to use, eg FORMAT_DEG_MIN_SEC
 282          * @return String for output
 283          */
 284         public String output(int inFormat)
 285         {
 286                 String answer = _originalString;
 287                 if (inFormat != FORMAT_NONE && inFormat != _originalFormat)
 288                 {
 289                         // TODO: allow specification of precision for output of d-m and d
 290                         // format as specified
 291                         switch (inFormat)
 292                         {
 293                                 case FORMAT_DEG_MIN_SEC:
 294                                 {
 295                                         StringBuffer buffer = new StringBuffer();
 296                                         buffer.append(PRINTABLE_CARDINALS[_cardinal])
 297                                                 .append(threeDigitString(_degrees)).append('\u00B0')
 298                                                 .append(twoDigitString(_minutes)).append('\'')
 299                                                 .append(twoDigitString(_seconds)).append('.')
 300                                                 .append(formatFraction(_fracs, _fracDenom));
 301                                         answer = buffer.toString();
 302                                         break;
 303                                 }
 304                                 case FORMAT_DEG_MIN:
 305                                 {
 306                                         answer = "" + PRINTABLE_CARDINALS[_cardinal] + threeDigitString(_degrees) + "\u00B0"
 307                                                 + FIVE_DP.format((Math.abs(_asDouble) - _degrees) * 60.0) + "'";
 308                                         break;
 309                                 }
 310                                 case FORMAT_DEG_WHOLE_MIN:
 311                                 {
 312                                         int deg = _degrees;
 313                                         int min = (int) Math.floor(_minutes + _seconds / 60.0 + _fracs / 60.0 / _fracDenom + 0.5);
 314                                         if (min == 60) {
 315                                                 min = 0; deg++;
 316                                         }
 317                                         answer = "" + PRINTABLE_CARDINALS[_cardinal] + threeDigitString(deg) + "\u00B0" + min + "'";
 318                                         break;
 319                                 }
 320                                 case FORMAT_DEG:
 321                                 case FORMAT_DEG_WITHOUT_CARDINAL:
 322                                 {
 323                                         if (_originalFormat != FORMAT_DEG_WITHOUT_CARDINAL)
 324                                         {
 325                                                 answer = (_asDouble<0.0?"-":"")
 326                                                         + (_degrees + _minutes / 60.0 + _seconds / 3600.0 + _fracs / 3600.0 / _fracDenom);
 327                                         }
 328                                         break;
 329                                 }
 330                                 case FORMAT_DECIMAL_FORCE_POINT:
 331                                 {
 332                                         // Forcing a decimal point instead of system-dependent commas etc
 333                                         if (_originalFormat != FORMAT_DEG_WITHOUT_CARDINAL || answer.indexOf('.') < 0) {
 334                                                 answer = EIGHT_DP.format(_asDouble);
 335                                         }
 336                                         break;
 337                                 }
 338                                 case FORMAT_DEG_MIN_SEC_WITH_SPACES:
 339                                 {
 340                                         // Note: cardinal not needed as this format is only for exif, which has cardinal separately
 341                                         answer = "" + _degrees + " " + _minutes + " " + _seconds + "." + formatFraction(_fracs, _fracDenom);
 342                                         break;
 343                                 }
 344                                 case FORMAT_CARDINAL:
 345                                 {
 346                                         answer = "" + PRINTABLE_CARDINALS[_cardinal];
 347                                         break;
 348                                 }
 349                         }
 350                 }
 351                 return answer;
 352         }
 353
 354         /**
 355          * Format the fraction part of seconds value
 356          * @param inFrac fractional part eg 123
 357          * @param inDenom denominator of fraction eg 10000
 358          * @return String describing fraction, in this case 0123
 359          */
 360         private static final String formatFraction(int inFrac, int inDenom)
 361         {
 362                 if (inDenom <= 1 || inFrac == 0) {return "" + inFrac;}
 363                 String denomString = "" + inDenom;
 364                 int reqdLen = denomString.length() - 1;
 365                 String result = denomString + inFrac;
 366                 int resultLen = result.length();
 367                 return result.substring(resultLen - reqdLen);
 368         }
 369
 370
 371         /**
 372          * Format an integer to a two-digit String
 373          * @param inNumber number to format
 374          * @return two-character String
 375          */
 376         private static String twoDigitString(int inNumber)
 377         {
 378                 if (inNumber <= 0) return "00";
 379                 if (inNumber < 10) return "0" + inNumber;
 380                 if (inNumber < 100) return "" + inNumber;
 381                 return "" + (inNumber % 100);
 382         }
 383
 384
 385         /**
 386          * Format an integer to a three-digit String for degrees
 387          * @param inNumber number to format
 388          * @return three-character String
 389          */
 390         private static String threeDigitString(int inNumber)
 391         {
 392                 if (inNumber <= 0) return "000";
 393                 if (inNumber < 10) return "00" + inNumber;
 394                 if (inNumber < 100) return "0" + inNumber;
 395                 return "" + (inNumber % 1000);
 396         }
 397
 398
 399         /**
 400          * Create a new Coordinate between two others
 401          * @param inStart start coordinate
 402          * @param inEnd end coordinate
 403          * @param inIndex index of point
 404          * @param inNumPoints number of points to interpolate
 405          * @return new Coordinate object
 406          */
 407         public static Coordinate interpolate(Coordinate inStart, Coordinate inEnd,
 408                 int inIndex, int inNumPoints)
 409         {
 410                 return interpolate(inStart, inEnd, 1.0 * (inIndex+1) / (inNumPoints + 1));
 411         }
 412
 413
 414         /**
 415          * Create a new Coordinate between two others
 416          * @param inStart start coordinate
 417          * @param inEnd end coordinate
 418          * @param inFraction fraction from start to end
 419          * @return new Coordinate object
 420          */
 421         public static Coordinate interpolate(Coordinate inStart, Coordinate inEnd,
 422                 double inFraction)
 423         {
 424                 double startValue = inStart.getDouble();
 425                 double endValue = inEnd.getDouble();
 426                 double newValue = startValue + (endValue - startValue) * inFraction;
 427                 Coordinate answer = inStart.makeNew(newValue, inStart._originalFormat);
 428                 return answer;
 429         }
 430
 431
 432         /**
 433          * Make a new Coordinate according to subclass
 434          * @param inValue double value
 435          * @param inFormat format to use
 436          * @return object of Coordinate subclass
 437          */
 438         protected abstract Coordinate makeNew(double inValue, int inFormat);
 439
 440         /**
 441          * Try to parse the given string
 442          * @param inString string to check
 443          * @return true if it can be parsed as a number
 444          */
 445         private static boolean isJustNumber(String inString)
 446         {
 447                 boolean justNum = false;
 448                 try {
 449                         double x = Double.parseDouble(inString);
 450                         justNum = (x >= -180.0 && x <= 360.0);
 451                 }
 452                 catch (NumberFormatException nfe) {} // flag remains false
 453                 return justNum;
 454         }
 455
 456         /**
 457          * Create a String representation for debug
 458          * @return String describing coordinate value
 459          */
 460         public String toString()
 461         {
 462                 return "Coord: " + _cardinal + " (" + _degrees + ") (" + _minutes + ") (" + _seconds + "."
 463                         + formatFraction(_fracs, _fracDenom) + ") = " + _asDouble;
 464         }
 465 }