src/tim/prune/load/xml/KmlHandler.java

   1 package tim.prune.load.xml;
   2
   3 import java.util.ArrayList;
   4 import org.xml.sax.Attributes;
   5 import org.xml.sax.SAXException;
   6
   7 import tim.prune.data.Field;
   8
   9
  10 /**
  11  * Class for handling specifics of parsing Kml files
  12  */
  13 public class KmlHandler extends XmlHandler
  14 {
  15         private boolean _insideCoordinates = false;
  16         private boolean _insideGxTrack = false;
  17         private String _value = null;
  18         private String _name = null, _desc = null;
  19         private String _timestamp = null, _imgLink = null;
  20         private StringBuffer _coordinates = null;
  21         private ArrayList<String> _coordinateList = null;
  22         private ArrayList<String[]> _pointList = new ArrayList<String[]>();
  23         private ArrayList<String> _linkList = new ArrayList<String>();
  24         // variables for gx extensions
  25         private ArrayList<String> _whenList = new ArrayList<String>();
  26         private ArrayList<String> _whereList = new ArrayList<String>();
  27
  28
  29         /**
  30          * Receive the start of a tag
  31          * @see org.xml.sax.ContentHandler#startElement(java.lang.String, java.lang.String, java.lang.String, org.xml.sax.Attributes)
  32          */
  33         public void startElement(String uri, String localName, String qName,
  34                 Attributes attributes) throws SAXException
  35         {
  36                 String tagName = localName;
  37                 if (tagName == null || tagName.equals("")) {tagName = qName;}
  38                 tagName = tagName.toLowerCase();
  39
  40                 if (tagName.equals("placemark"))
  41                 {
  42                         _coordinateList = new ArrayList<String>();
  43                 }
  44                 else if (tagName.equals("coordinates"))
  45                 {
  46                         _insideCoordinates = true;
  47                         _coordinates = null;
  48                 }
  49                 else if (tagName.equals("gx:track"))
  50                 {
  51                         _insideGxTrack = true;
  52                 }
  53                 _value = null;
  54                 super.startElement(uri, localName, qName, attributes);
  55         }
  56
  57
  58         /**
  59          * Process end tag
  60          * @see org.xml.sax.ContentHandler#endElement(java.lang.String, java.lang.String, java.lang.String)
  61          */
  62         public void endElement(String uri, String localName, String qName)
  63         throws SAXException
  64         {
  65                 String tagName = localName;
  66                 if (tagName == null || tagName.equals("")) {tagName = qName;}
  67                 tagName = tagName.toLowerCase();
  68
  69                 if (tagName.equals("placemark"))
  70                 {
  71                         processPlacemark();
  72                         _name = _desc = _imgLink = _timestamp = null;
  73                 }
  74                 else if (tagName.equals("coordinates"))
  75                 {
  76                         _insideCoordinates = false;
  77                         if (_coordinates != null) _coordinateList.add(_coordinates.toString().trim());
  78                 }
  79                 else if (tagName.equals("name"))
  80                 {
  81                         _name = _value;
  82                 }
  83                 else if (tagName.equals("description"))
  84                 {
  85                         _desc = _value;
  86                         _imgLink = getImgLink(_desc);
  87                 }
  88                 else if (tagName.equals("when"))
  89                 {
  90                         if (!_insideGxTrack)
  91                                 _timestamp = _value;
  92                         else
  93                                 _whenList.add(_value);
  94                 }
  95                 else if (tagName.equals("gx:coord"))
  96                 {
  97                         if (_insideGxTrack) {
  98                                 _whereList.add(_value);
  99                         }
 100                 }
 101                 else if (tagName.equals("gx:track"))
 102                 {
 103                         processGxTrack();
 104                         _insideGxTrack = false;
 105                 }
 106                 super.endElement(uri, localName, qName);
 107         }
 108
 109
 110         /**
 111          * Process character text (inside tags or between them)
 112          * @see org.xml.sax.ContentHandler#characters(char[], int, int)
 113          */
 114         public void characters(char[] ch, int start, int length)
 115                         throws SAXException
 116         {
 117                 String val = new String(ch, start, length);
 118                 if (_insideCoordinates)
 119                 {
 120                         if (_coordinates == null) {
 121                                 _coordinates = new StringBuffer();
 122                         }
 123                         _coordinates.append(val);
 124                 }
 125                 else
 126                 {
 127                         // Store string in _value
 128                         if (_value == null) _value = val;
 129                         else _value = _value + val;
 130                 }
 131                 super.characters(ch, start, length);
 132         }
 133
 134
 135         /**
 136          * Process a placemark entry, either a single waypoint or a whole track
 137          */
 138         private void processPlacemark()
 139         {
 140                 if (_coordinateList == null || _coordinateList.isEmpty()) return;
 141                 final boolean isSingleSelection = (_coordinateList.size() == 1);
 142                 // Loop over coordinate sets in list (may have multiple <coordinates> tags within single placemark)
 143                 for (String coords : _coordinateList)
 144                 {
 145                         String[] coordArray = coords.split("[ \n]");
 146                         int numPoints = coordArray.length;
 147                         if (numPoints == 1)
 148                         {
 149                                 // Add single point to list
 150                                 final String name = (isSingleSelection ? _name : null);
 151                                 _pointList.add(makeStringArray(coords, name, _desc, _timestamp));
 152                                 _linkList.add(_imgLink);
 153                         }
 154                         else if (numPoints > 1)
 155                         {
 156                                 // Add each of the unnamed track points to list
 157                                 boolean firstPoint = true;
 158                                 for (int p=0; p<numPoints; p++)
 159                                 {
 160                                         if (coordArray[p] != null && coordArray[p].trim().length()>3)
 161                                         {
 162                                                 String[] pointArray = makeStringArray(coordArray[p], null, null, null);
 163                                                 if (firstPoint) {pointArray[5] = "1";} // start of segment flag
 164                                                 firstPoint = false;
 165                                                 _pointList.add(pointArray);
 166                                         }
 167                                         _linkList.add(null);
 168                                 }
 169                         }
 170                 }
 171         }
 172
 173         /**
 174          * Process a Gx track including timestamps
 175          */
 176         private void processGxTrack()
 177         {
 178                 if (!_whereList.isEmpty())
 179                 {
 180                         // If the whens don't match, then throw them all away
 181                         if (_whenList.size() != _whereList.size()) {System.out.println("clearing!"); _whenList.clear();}
 182
 183                         // Add each of the unnamed track points to list
 184                         boolean firstPoint = true;
 185                         final int numPoints = _whenList.size();
 186                         for (int p=0; p < numPoints; p++)
 187                         {
 188                                 String when  = (_whenList.isEmpty() ? null : _whenList.get(p));
 189                                 String where = _whereList.get(p);
 190                                 if (where != null)
 191                                 {
 192                                         String[] coords = where.split(" ");
 193                                         if (coords.length == 3)
 194                                         {
 195                                                 String[] pointArray = new String[7];
 196                                                 pointArray[0] = coords[0];
 197                                                 pointArray[1] = coords[1];
 198                                                 pointArray[2] = coords[2];
 199                                                 // leave name and description empty
 200                                                 if (firstPoint) {pointArray[5] = "1";} // start of segment flag
 201                                                 firstPoint = false;
 202                                                 pointArray[6] = when; // timestamp
 203                                                 _pointList.add(pointArray);
 204                                         }
 205                                 }
 206                                 _linkList.add(null);
 207                         }
 208                 }
 209                 _whenList.clear();
 210                 _whereList.clear();
 211         }
 212
 213         /**
 214          * Extract an image link from the point description
 215          * @param inDesc description tag contents
 216          * @return image link if found or null
 217          */
 218         private static String getImgLink(String inDesc)
 219         {
 220                 if (inDesc == null || inDesc.equals("")) {return null;}
 221                 // Pull out <img tag from description (if any)
 222                 int spos = inDesc.indexOf("<img");
 223                 int epos = inDesc.indexOf('>', spos + 10);
 224                 if (spos < 0 || epos < 0) return null;
 225                 String imgtag = inDesc.substring(spos + 4, epos);
 226                 // Find the src attribute from img tag
 227                 int quotepos = imgtag.toLowerCase().indexOf("src=");
 228                 if (quotepos < 0) return null;
 229                 // source may be quoted with single or double quotes
 230                 char quotechar = imgtag.charAt(quotepos + 4);
 231                 int equotepos = imgtag.indexOf(quotechar, quotepos + 7);
 232                 if (equotepos < 0) return null;
 233                 return imgtag.substring(quotepos + 5, equotepos);
 234         }
 235
 236         /**
 237          * Construct the String array for the given coordinates and name
 238          * @param inCoordinates coordinate string in Kml format
 239          * @param inName name of waypoint, or null if track point
 240          * @param inDesc description of waypoint, if any
 241          * @param inDesc timestamp of waypoint, if any
 242          * @return String array for point
 243          */
 244         private static String[] makeStringArray(String inCoordinates,
 245                 String inName, String inDesc, String inTimestamp)
 246         {
 247                 String[] result = new String[7];
 248                 String[] values = inCoordinates.split(",");
 249                 final int numValues = values.length;
 250                 if (numValues == 3 || numValues == 2) {
 251                         System.arraycopy(values, 0, result, 0, numValues);
 252                 }
 253                 result[3] = inName;
 254                 result[4] = inDesc;
 255                 result[6] = inTimestamp;
 256                 return result;
 257         }
 258
 259
 260         /**
 261          * @see tim.prune.load.xml.XmlHandler#getFieldArray()
 262          */
 263         public Field[] getFieldArray()
 264         {
 265                 final Field[] fields = {Field.LONGITUDE, Field.LATITUDE, Field.ALTITUDE,
 266                         Field.WAYPT_NAME, Field.DESCRIPTION, Field.NEW_SEGMENT, Field.TIMESTAMP};
 267                 return fields;
 268         }
 269
 270
 271         /**
 272          * Return the parsed information as a 2d array
 273          * @see tim.prune.load.xml.XmlHandler#getDataArray()
 274          */
 275         public String[][] getDataArray()
 276         {
 277                 int numPoints = _pointList.size();
 278                 // construct data array
 279                 String[][] result = new String[numPoints][];
 280                 for (int i=0; i<numPoints; i++) {
 281                         result[i] = _pointList.get(i);
 282                 }
 283                 return result;
 284         }
 285
 286         /**
 287          * @return array of links, or null if none
 288          */
 289         public String[] getLinkArray()
 290         {
 291                 int numPoints = _linkList.size();
 292                 boolean hasLink = false;
 293                 String[] result = new String[numPoints];
 294                 for (int i=0; i<numPoints; i++)
 295                 {
 296                         result[i] = _linkList.get(i);
 297                         if (result[i] != null) {hasLink = true;}
 298                 }
 299                 if (!hasLink) {result = null;}
 300                 return result;
 301         }
 302 }