tim/prune/load/xml/GpxHandler.java

   1 package tim.prune.load.xml;
   2
   3 import java.util.ArrayList;
   4
   5 import org.xml.sax.Attributes;
   6 import org.xml.sax.SAXException;
   7
   8 import tim.prune.data.Field;
   9 import tim.prune.load.TrackNameList;
  10
  11
  12 /**
  13  * Class for handling specifics of parsing Gpx files
  14  */
  15 public class GpxHandler extends XmlHandler
  16 {
  17         private boolean _insidePoint = false;
  18         private boolean _insideWaypoint = false;
  19         private boolean _startSegment = true;
  20         private boolean _isTrackPoint = false;
  21         private int _trackNum = -1;
  22         private GpxTag _name = new GpxTag(), _trackName = new GpxTag();
  23         private String _latitude = null, _longitude = null;
  24         private GpxTag _elevation = new GpxTag(), _time = new GpxTag();
  25         private GpxTag _type = new GpxTag(), _link = new GpxTag();
  26         private GpxTag _currentTag = null;
  27         private ArrayList<String[]> _pointList = new ArrayList<String[]>();
  28         private ArrayList<String> _linkList = new ArrayList<String>();
  29         private TrackNameList _trackNameList = new TrackNameList();
  30
  31
  32         /**
  33          * Receive the start of a tag
  34          * @see org.xml.sax.ContentHandler#startElement(java.lang.String, java.lang.String, java.lang.String, org.xml.sax.Attributes)
  35          */
  36         public void startElement(String uri, String localName, String qName,
  37                 Attributes attributes) throws SAXException
  38         {
  39                 // Read the parameters for waypoints and track points
  40                 String tag = qName.toLowerCase();
  41                 if (tag.equals("wpt") || tag.equals("trkpt") || tag.equals("rtept"))
  42                 {
  43                         _insidePoint = true;
  44                         _insideWaypoint = tag.equals("wpt");
  45                         _isTrackPoint = tag.equals("trkpt");
  46                         final int numAttributes = attributes.getLength();
  47                         for (int i=0; i<numAttributes; i++)
  48                         {
  49                                 String att = attributes.getQName(i).toLowerCase();
  50                                 if (att.equals("lat")) {_latitude = attributes.getValue(i);}
  51                                 else if (att.equals("lon")) {_longitude = attributes.getValue(i);}
  52                         }
  53                         _elevation.setValue(null);
  54                         _name.setValue(null);
  55                         _time.setValue(null);
  56                         _type.setValue(null);
  57                         _link.setValue(null);
  58                 }
  59                 else if (tag.equals("ele")) {
  60                         _currentTag = _elevation;
  61                 }
  62                 else if (tag.equals("name")) {
  63                         _currentTag = (_insidePoint?_name:_trackName);
  64                 }
  65                 else if (tag.equals("time")) {
  66                         _currentTag = _time;
  67                 }
  68                 else if (tag.equals("type")) {
  69                         _currentTag = _type;
  70                 }
  71                 else if (tag.equals("link")) {
  72                         _link.setValue(attributes.getValue("href"));
  73                 }
  74                 else if (tag.equals("trkseg")) {
  75                         _startSegment = true;
  76                 }
  77                 else if (tag.equals("trk"))
  78                 {
  79                         _trackNum++;
  80                         _trackName.setValue(null);
  81                 }
  82                 super.startElement(uri, localName, qName, attributes);
  83         }
  84
  85
  86         /**
  87          * Process end tag
  88          * @see org.xml.sax.ContentHandler#endElement(java.lang.String, java.lang.String, java.lang.String)
  89          */
  90         public void endElement(String uri, String localName, String qName)
  91                 throws SAXException
  92         {
  93                 String tag = qName.toLowerCase();
  94                 if (tag.equals("wpt") || tag.equals("trkpt") || tag.equals("rtept"))
  95                 {
  96                         processPoint();
  97                         _insidePoint = false;
  98                 }
  99                 else {
 100                         _currentTag = null;
 101                 }
 102                 super.endElement(uri, localName, qName);
 103         }
 104
 105
 106         /**
 107          * Process character text (inside tags or between them)
 108          * @see org.xml.sax.ContentHandler#characters(char[], int, int)
 109          */
 110         public void characters(char[] ch, int start, int length)
 111                 throws SAXException
 112         {
 113                 String value = new String(ch, start, length);
 114                 if (_currentTag != null) {
 115                         _currentTag.setValue(checkCharacters(_currentTag.getValue(), value));
 116                 }
 117                 super.characters(ch, start, length);
 118         }
 119
 120
 121         /**
 122          * Check to concatenate partially-received values, if necessary
 123          * @param inVariable variable containing characters received until now
 124          * @param inValue new value received
 125          * @return concatenation
 126          */
 127         private static String checkCharacters(String inVariable, String inValue)
 128         {
 129                 if (inVariable == null) {return inValue;}
 130                 return inVariable + inValue;
 131         }
 132
 133
 134         /**
 135          * Process a point, either a waypoint or track point
 136          */
 137         private void processPoint()
 138         {
 139                 // Put the values into a String array matching the order in getFieldArray()
 140                 String[] values = new String[7];
 141                 values[0] = _latitude;
 142                 values[1] = _longitude;
 143                 values[2] = _elevation.getValue();
 144                 if (_insideWaypoint) {values[3] = _name.getValue();}
 145                 values[4] = _time.getValue();
 146                 if (_startSegment && !_insideWaypoint) {
 147                         values[5] = "1";
 148                         _startSegment = false;
 149                 }
 150                 values[6] = _type.getValue();
 151                 _pointList.add(values);
 152                 _trackNameList.addPoint(_trackNum, _trackName.getValue(), _isTrackPoint);
 153                 _linkList.add(_link.getValue());
 154         }
 155
 156
 157         /**
 158          * @see tim.prune.load.xml.XmlHandler#getFieldArray()
 159          */
 160         public Field[] getFieldArray()
 161         {
 162                 final Field[] fields = {Field.LATITUDE, Field.LONGITUDE, Field.ALTITUDE,
 163                         Field.WAYPT_NAME, Field.TIMESTAMP, Field.NEW_SEGMENT, Field.WAYPT_TYPE};
 164                 return fields;
 165         }
 166
 167
 168         /**
 169          * Return the parsed information as a 2d array
 170          * @see tim.prune.load.xml.XmlHandler#getDataArray()
 171          */
 172         public String[][] getDataArray()
 173         {
 174                 int numPoints = _pointList.size();
 175                 // construct data array
 176                 String[][] result = new String[numPoints][];
 177                 for (int i=0; i<numPoints; i++)
 178                 {
 179                         result[i] = _pointList.get(i);
 180                 }
 181                 return result;
 182         }
 183
 184         /**
 185          * @return array of links, or null if none
 186          */
 187         public String[] getLinkArray()
 188         {
 189                 int numPoints = _linkList.size();
 190                 boolean hasLink = false;
 191                 String[] result = new String[numPoints];
 192                 for (int i=0; i<numPoints; i++)
 193                 {
 194                         result[i] = _linkList.get(i);
 195                         if (result[i] != null) {hasLink = true;}
 196                 }
 197                 if (!hasLink) {result = null;}
 198                 return result;
 199         }
 200
 201         /**
 202          * @return track name list
 203          */
 204         public TrackNameList getTrackNameList() {
 205                 return _trackNameList;
 206         }
 207 }