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