tim/prune/data/Coordinate.java

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