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