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