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 _fileTitle = new GpxTag();
  23         private GpxTag _pointName = new GpxTag(), _trackName = new GpxTag();
  24         private String _latitude = null, _longitude = null;
  25         private GpxTag _elevation = new GpxTag(), _time = new GpxTag();
  26         private GpxTag _type = new GpxTag(), _description = new GpxTag();
  27         private GpxTag _link = new GpxTag();
  28         private GpxTag _currentTag = null;
  29         private ArrayList<String[]> _pointList = new ArrayList<String[]>();
  30         private ArrayList<String> _linkList = new ArrayList<String>();
  31         private TrackNameList _trackNameList = new TrackNameList();
  32
  33
  34         /**
  35          * Receive the start of a tag
  36          * @see org.xml.sax.ContentHandler#startElement(java.lang.String, java.lang.String, java.lang.String, org.xml.sax.Attributes)
  37          */
  38         public void startElement(String uri, String localName, String qName,
  39                 Attributes attributes) throws SAXException
  40         {
  41                 // Read the parameters for waypoints and track points
  42                 String tag = qName.toLowerCase();
  43                 if (tag.equals("wpt") || tag.equals("trkpt") || tag.equals("rtept"))
  44                 {
  45                         _insidePoint = true;
  46                         _insideWaypoint = tag.equals("wpt");
  47                         _isTrackPoint = tag.equals("trkpt");
  48                         final int numAttributes = attributes.getLength();
  49                         for (int i=0; i<numAttributes; i++)
  50                         {
  51                                 String att = attributes.getQName(i).toLowerCase();
  52                                 if (att.equals("lat")) {_latitude = attributes.getValue(i);}
  53                                 else if (att.equals("lon")) {_longitude = attributes.getValue(i);}
  54                         }
  55                         _elevation.setValue(null);
  56                         _pointName.setValue(null);
  57                         _time.setValue(null);
  58                         _type.setValue(null);
  59                         _link.setValue(null);
  60                         _description.setValue(null);
  61                 }
  62                 else if (tag.equals("ele")) {
  63                         _currentTag = _elevation;
  64                 }
  65                 else if (tag.equals("name"))
  66                 {
  67                         if (_insidePoint) {
  68                                 _currentTag = _pointName;
  69                         }
  70                         else if (_trackNum < 0)
  71                         {
  72                                 _currentTag = _fileTitle;
  73                         }
  74                         else {
  75                                 _currentTag = _trackName;
  76                         }
  77                 }
  78                 else if (tag.equals("time")) {
  79                         _currentTag = _time;
  80                 }
  81                 else if (tag.equals("type")) {
  82                         _currentTag = _type;
  83                 }
  84                 else if (tag.equals("description") || tag.equals("desc")) {
  85                         _currentTag = _description;
  86                 }
  87                 else if (tag.equals("link")) {
  88                         _link.setValue(attributes.getValue("href"));
  89                 }
  90                 else if (tag.equals("trkseg")) {
  91                         _startSegment = true;
  92                 }
  93                 else if (tag.equals("trk"))
  94                 {
  95                         _trackNum++;
  96                         _trackName.setValue(null);
  97                 }
  98                 super.startElement(uri, localName, qName, attributes);
  99         }
 100
 101
 102         /**
 103          * Process end tag
 104          * @see org.xml.sax.ContentHandler#endElement(java.lang.String, java.lang.String, java.lang.String)
 105          */
 106         public void endElement(String uri, String localName, String qName)
 107                 throws SAXException
 108         {
 109                 String tag = qName.toLowerCase();
 110                 if (tag.equals("wpt") || tag.equals("trkpt") || tag.equals("rtept"))
 111                 {
 112                         processPoint();
 113                         _insidePoint = false;
 114                 }
 115                 else {
 116                         _currentTag = null;
 117                 }
 118                 super.endElement(uri, localName, qName);
 119         }
 120
 121
 122         /**
 123          * Process character text (inside tags or between them)
 124          * @see org.xml.sax.ContentHandler#characters(char[], int, int)
 125          */
 126         public void characters(char[] ch, int start, int length)
 127                 throws SAXException
 128         {
 129                 String value = new String(ch, start, length);
 130                 if (_currentTag != null) {
 131                         _currentTag.setValue(checkCharacters(_currentTag.getValue(), value));
 132                 }
 133                 super.characters(ch, start, length);
 134         }
 135
 136
 137         /**
 138          * Check to concatenate partially-received values, if necessary
 139          * @param inVariable variable containing characters received until now
 140          * @param inValue new value received
 141          * @return concatenation
 142          */
 143         private static String checkCharacters(String inVariable, String inValue)
 144         {
 145                 if (inVariable == null) {return inValue;}
 146                 return inVariable + inValue;
 147         }
 148
 149
 150         /**
 151          * Process a point, either a waypoint or track point
 152          */
 153         private void processPoint()
 154         {
 155                 // Put the values into a String array matching the order in getFieldArray()
 156                 String[] values = new String[8];
 157                 values[0] = _latitude;
 158                 values[1] = _longitude;
 159                 values[2] = _elevation.getValue();
 160                 if (_insideWaypoint) {values[3] = _pointName.getValue();}
 161                 values[4] = _time.getValue();
 162                 if (_startSegment && !_insideWaypoint)
 163                 {
 164                         values[5] = "1";
 165                         _startSegment = false;
 166                 }
 167                 values[6] = _type.getValue();
 168                 values[7] = _description.getValue();
 169                 _pointList.add(values);
 170                 _trackNameList.addPoint(_trackNum, _trackName.getValue(), _isTrackPoint);
 171                 _linkList.add(_link.getValue());
 172         }
 173
 174
 175         /**
 176          * @see tim.prune.load.xml.XmlHandler#getFieldArray()
 177          */
 178         public Field[] getFieldArray()
 179         {
 180                 final Field[] fields = {Field.LATITUDE, Field.LONGITUDE, Field.ALTITUDE,
 181                         Field.WAYPT_NAME, Field.TIMESTAMP, Field.NEW_SEGMENT,
 182                         Field.WAYPT_TYPE, Field.DESCRIPTION};
 183                 return fields;
 184         }
 185
 186
 187         /**
 188          * Return the parsed information as a 2d array
 189          * @see tim.prune.load.xml.XmlHandler#getDataArray()
 190          */
 191         public String[][] getDataArray()
 192         {
 193                 int numPoints = _pointList.size();
 194                 // construct data array
 195                 String[][] result = new String[numPoints][];
 196                 for (int i=0; i<numPoints; i++)
 197                 {
 198                         result[i] = _pointList.get(i);
 199                 }
 200                 return result;
 201         }
 202
 203         /**
 204          * @return array of links, or null if none
 205          */
 206         public String[] getLinkArray()
 207         {
 208                 int numPoints = _linkList.size();
 209                 boolean hasLink = false;
 210                 String[] result = new String[numPoints];
 211                 for (int i=0; i<numPoints; i++)
 212                 {
 213                         result[i] = _linkList.get(i);
 214                         if (result[i] != null) {hasLink = true;}
 215                 }
 216                 if (!hasLink) {result = null;}
 217                 return result;
 218         }
 219
 220         /**
 221          * @return track name list
 222          */
 223         public TrackNameList getTrackNameList() {
 224                 return _trackNameList;
 225         }
 226
 227         /**
 228          * @return file title
 229          */
 230         public String getFileTitle() {
 231                 return _fileTitle.getValue();
 232         }
 233 }