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
  10
  11 /**
  12  * Class for handling specifics of parsing Gpx files
  13  */
  14 public class GpxHandler extends XmlHandler
  15 {
  16         private boolean _insideWaypoint = false;
  17         private boolean _insideName = false;
  18         private boolean _insideElevation = false;
  19         private boolean _insideTime = false;
  20 //      private boolean _insideType = false;
  21         private boolean _startSegment = true;
  22         private String _name = null, _latitude = null, _longitude = null;
  23         private String _elevation = null;
  24         private String _time = null;
  25 //      private String _type = null;
  26         private ArrayList<String[]> _pointList = new ArrayList<String[]>();
  27
  28         // FIXME: Read waypoint type too
  29
  30         /**
  31          * Receive the start of a tag
  32          * @see org.xml.sax.ContentHandler#startElement(java.lang.String, java.lang.String, java.lang.String, org.xml.sax.Attributes)
  33          */
  34         public void startElement(String uri, String localName, String qName,
  35                 Attributes attributes) throws SAXException
  36         {
  37                 // Read the parameters for waypoints and track points
  38                 if (qName.equalsIgnoreCase("wpt") || qName.equalsIgnoreCase("trkpt"))
  39                 {
  40                         _insideWaypoint = qName.equalsIgnoreCase("wpt");
  41                         int numAttributes = attributes.getLength();
  42                         for (int i=0; i<numAttributes; i++)
  43                         {
  44                                 String att = attributes.getQName(i);
  45                                 if (att.equals("lat")) {_latitude = attributes.getValue(i);}
  46                                 else if (att.equals("lon")) {_longitude = attributes.getValue(i);}
  47                         }
  48                         _elevation = null;
  49                         _name = null;
  50                         _time = null;
  51                 }
  52                 else if (qName.equalsIgnoreCase("ele"))
  53                 {
  54                         _insideElevation = true;
  55                 }
  56                 else if (qName.equalsIgnoreCase("name"))
  57                 {
  58                         _insideName = true;
  59                 }
  60                 else if (qName.equalsIgnoreCase("time"))
  61                 {
  62                         _insideTime = true;
  63                 }
  64 //              else if (qName.equalsIgnoreCase("type"))
  65 //              {
  66 //                      _insideType = true;
  67 //              }
  68                 else if (qName.equalsIgnoreCase("trkseg"))
  69                 {
  70                         _startSegment = true;
  71                 }
  72                 super.startElement(uri, localName, qName, attributes);
  73         }
  74
  75
  76         /**
  77          * Process end tag
  78          * @see org.xml.sax.ContentHandler#endElement(java.lang.String, java.lang.String, java.lang.String)
  79          */
  80         public void endElement(String uri, String localName, String qName)
  81                 throws SAXException
  82         {
  83                 if (qName.equalsIgnoreCase("wpt") || qName.equalsIgnoreCase("trkpt"))
  84                 {
  85                         processPoint();
  86                 }
  87                 else if (qName.equalsIgnoreCase("ele"))
  88                 {
  89                         _insideElevation = false;
  90                 }
  91                 else if (qName.equalsIgnoreCase("name"))
  92                 {
  93                         _insideName = false;
  94                 }
  95                 else if (qName.equalsIgnoreCase("time"))
  96                 {
  97                         _insideTime = false;
  98                 }
  99                 super.endElement(uri, localName, qName);
 100         }
 101
 102
 103         /**
 104          * Process character text (inside tags or between them)
 105          * @see org.xml.sax.ContentHandler#characters(char[], int, int)
 106          */
 107         public void characters(char[] ch, int start, int length)
 108                 throws SAXException
 109         {
 110                 String value = new String(ch, start, length);
 111                 if (_insideName && _insideWaypoint) {_name = checkCharacters(_name, value);}
 112                 else if (_insideElevation) {_elevation = checkCharacters(_elevation, value);}
 113                 else if (_insideTime) {_time = checkCharacters(_time, value);}
 114                 super.characters(ch, start, length);
 115         }
 116
 117
 118         /**
 119          * Check to concatenate partially-received values, if necessary
 120          * @param inVariable variable containing characters received until now
 121          * @param inValue new value received
 122          * @return concatenation
 123          */
 124         private static String checkCharacters(String inVariable, String inValue)
 125         {
 126                 if (inVariable == null) {return inValue;}
 127                 return inVariable + inValue;
 128         }
 129
 130
 131         /**
 132          * Process a point, either a waypoint or track point
 133          */
 134         private void processPoint()
 135         {
 136                 // Put the values into a String array matching the order in getFieldArray()
 137                 String[] values = new String[6];
 138                 values[0] = _latitude; values[1] = _longitude;
 139                 values[2] = _elevation; values[3] = _name;
 140                 values[4] = _time;
 141                 if (_startSegment && !_insideWaypoint) {
 142                         values[5] = "1";
 143                         _startSegment = false;
 144                 }
 145                 _pointList.add(values);
 146         }
 147
 148
 149         /**
 150          * @see tim.prune.load.xml.XmlHandler#getFieldArray()
 151          */
 152         public Field[] getFieldArray()
 153         {
 154                 final Field[] fields = {Field.LATITUDE, Field.LONGITUDE, Field.ALTITUDE,
 155                         Field.WAYPT_NAME, Field.TIMESTAMP, Field.NEW_SEGMENT};
 156                 return fields;
 157         }
 158
 159
 160         /**
 161          * Return the parsed information as a 2d array
 162          * @see tim.prune.load.xml.XmlHandler#getDataArray()
 163          */
 164         public String[][] getDataArray()
 165         {
 166                 int numPoints = _pointList.size();
 167                 // construct data array
 168                 String[][] result = new String[numPoints][];
 169                 for (int i=0; i<numPoints; i++)
 170                 {
 171                         result[i] = _pointList.get(i);
 172                 }
 173                 return result;
 174         }
 175 }