/*
* Geopaparazzi - Digital field mapping on Android based devices
* Copyright (C) 2016 HydroloGIS (www.hydrologis.com)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package eu.geopaparazzi.library.gpx.parser;
import java.io.FileReader;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
import org.xml.sax.helpers.DefaultHandler;
import eu.geopaparazzi.library.database.GPLog;
/**
* A very basic KML parser to meet the need of the emulator control panel.
* <p/>
* It parses basic Placemark information.
*/
public class KmlParser {
private final static String NS_KML_2 = "http://earth.google.com/kml/2."; //$NON-NLS-1$
private final static String NODE_PLACEMARK = "Placemark"; //$NON-NLS-1$
private final static String NODE_NAME = "name"; //$NON-NLS-1$
private final static String NODE_COORDINATES = "coordinates"; //$NON-NLS-1$
private final static Pattern sLocationPattern = Pattern.compile("([^,]+),([^,]+)(?:,([^,]+))?"); //$NON-NLS-1$
private static SAXParserFactory sParserFactory;
static {
sParserFactory = SAXParserFactory.newInstance();
sParserFactory.setNamespaceAware(true);
}
private String mFileName;
private KmlHandler mHandler;
/**
* Handler for the SAX parser.
*/
private static class KmlHandler extends DefaultHandler {
// --------- parsed data ---------
List<WayPoint> mWayPoints;
// --------- state for parsing ---------
WayPoint mCurrentWayPoint;
final StringBuilder mStringAccumulator = new StringBuilder();
boolean mSuccess = true;
@Override
public void startElement( String uri, String localName, String name, Attributes attributes ) throws SAXException {
// we only care fragment_about the standard GPX nodes.
try {
if (uri.startsWith(NS_KML_2)) {
if (NODE_PLACEMARK.equals(localName)) {
if (mWayPoints == null) {
mWayPoints = new ArrayList<WayPoint>();
}
mWayPoints.add(mCurrentWayPoint = new WayPoint());
}
}
} finally {
// no matter the node, we empty the StringBuilder accumulator when we start
// a new node.
mStringAccumulator.setLength(0);
}
}
/**
* Processes new characters for the node content. The characters are simply stored,
* and will be processed when {@link #endElement(String, String, String)} is called.
*/
@Override
public void characters( char[] ch, int start, int length ) throws SAXException {
mStringAccumulator.append(ch, start, length);
}
@Override
public void endElement( String uri, String localName, String name ) throws SAXException {
if (uri.startsWith(NS_KML_2)) {
if (NODE_PLACEMARK.equals(localName)) {
mCurrentWayPoint = null;
} else if (NODE_NAME.equals(localName)) {
if (mCurrentWayPoint != null) {
mCurrentWayPoint.setName(mStringAccumulator.toString());
}
} else if (NODE_COORDINATES.equals(localName)) {
if (mCurrentWayPoint != null) {
parseLocation(mCurrentWayPoint, mStringAccumulator.toString());
}
}
}
}
@Override
public void error( SAXParseException e ) throws SAXException {
mSuccess = false;
}
@Override
public void fatalError( SAXParseException e ) throws SAXException {
mSuccess = false;
}
/**
* Parses the location string and store the information into a {@link LocationPoint}.
* @param locationNode the {@link LocationPoint} to receive the location data.
* @param location The string containing the location info.
*/
private void parseLocation( LocationPoint locationNode, String location ) {
Matcher m = sLocationPattern.matcher(location);
if (m.matches()) {
try {
double longitude = Double.parseDouble(m.group(1));
double latitude = Double.parseDouble(m.group(2));
locationNode.setLocation(longitude, latitude);
if (m.groupCount() == 3) {
// looks like we have elevation data.
locationNode.setElevation(Double.parseDouble(m.group(3)));
}
} catch (NumberFormatException e) {
// wrong data, do nothing.
}
}
}
WayPoint[] getWayPoints() {
if (mWayPoints != null) {
return mWayPoints.toArray(new WayPoint[mWayPoints.size()]);
}
return null;
}
boolean getSuccess() {
return mSuccess;
}
}
/**
* Creates a new GPX parser for a file specified by its full path.
* @param fileName The full path of the GPX file to parse.
*/
public KmlParser( String fileName ) {
mFileName = fileName;
}
/**
* Parses the KML file.
*
* @return <code>true</code> if success.
*/
public boolean parse() {
try {
SAXParser parser = sParserFactory.newSAXParser();
mHandler = new KmlHandler();
parser.parse(new InputSource(new FileReader(mFileName)), mHandler);
return mHandler.getSuccess();
} catch (Exception e) {
GPLog.error(this, null, e);
}
return false;
}
/**
* Returns the parsed {@link WayPoint} objects, or <code>null</code> if none were found (or
* if the parsing failed.
*
* @return array of waypoints.
*/
public WayPoint[] getWayPoints() {
if (mHandler != null) {
return mHandler.getWayPoints();
}
return null;
}
}