GpxWriter.java

/*
Copyright (C) 2001, 2007 United States Government as represented by
the Administrator of the National Aeronautics and Space Administration.
All Rights Reserved.
*/
package gov.nasa.worldwind.formats.gpx;

import gov.nasa.worldwind.util.Logging;
import gov.nasa.worldwind.tracks.Track;
import gov.nasa.worldwind.tracks.TrackSegment;
import gov.nasa.worldwind.tracks.TrackPoint;

/**
 * @author dcollins
 * @version $Id: GpxWriter.java 4862 2008-03-30 01:25:38Z dcollins $
 */
public class GpxWriter
{
    private final org.w3c.dom.Document doc;
    private final javax.xml.transform.Result result;

    public GpxWriter(String path) throws java.io.IOException, javax.xml.parsers.ParserConfigurationException
    {
        if (path == null)
        {
            String msg = Logging.getMessage("nullValue.PathIsNull");
            Logging.logger().severe(msg);
            throw new IllegalArgumentException(msg);
        }

        javax.xml.parsers.DocumentBuilderFactory factory = javax.xml.parsers.DocumentBuilderFactory.newInstance();
        this.doc = factory.newDocumentBuilder().newDocument();
        this.result = new javax.xml.transform.stream.StreamResult(new java.io.File(path));
        createGpxDocument(this.doc);
    }

    public GpxWriter(java.io.OutputStream stream) throws java.io.IOException, javax.xml.parsers.ParserConfigurationException
    {
        if (stream == null)
        {
            String msg = Logging.getMessage("nullValue.InputStreamIsNull");
            Logging.logger().severe(msg);
            throw new IllegalArgumentException(msg);
        }

        javax.xml.parsers.DocumentBuilderFactory factory = javax.xml.parsers.DocumentBuilderFactory.newInstance();
        this.doc = factory.newDocumentBuilder().newDocument();
        this.result = new javax.xml.transform.stream.StreamResult(stream);
        createGpxDocument(this.doc);
    }

    public void writeTrack(Track track) throws javax.xml.transform.TransformerException
    {
        if (track == null)
        {
            String msg = Logging.getMessage("nullValue.TrackIsNull");
            Logging.logger().severe(msg);
            throw new IllegalArgumentException(msg);
        }

        doWriteTrack(track, this.doc.getDocumentElement());
        doFlush();
    }

    public void close()
    {
        // Intentionally left blank,
        // as a placeholder for future functionality.
    }

    private void createGpxDocument(org.w3c.dom.Document doc)
    {
        // Create the GPX document root when the document
        // doesn't already have a root element.
        if (doc != null)
        {
            if (doc.getDocumentElement() != null)
                doc.removeChild(doc.getDocumentElement());

            doc.setXmlStandalone(false);

            org.w3c.dom.Element gpx = doc.createElement("gpx");
            gpx.setAttribute("version", "1.1");
            gpx.setAttribute("creator", "NASA World Wind");
            doc.appendChild(gpx);
        }
    }

    private void doWriteTrack(Track track, org.w3c.dom.Element elem)
    {
        if (track != null)
        {
            org.w3c.dom.Element trk = this.doc.createElement("trk");

            if (track.getName() != null)
            {
                org.w3c.dom.Element name = this.doc.createElement("name");
                org.w3c.dom.Text nameText = this.doc.createTextNode(track.getName());
                name.appendChild(nameText);
                trk.appendChild(name);
            }

            if (track.getSegments() != null)
            {
                for (TrackSegment ts : track.getSegments())
                    doWriteTrackSegment(ts, trk);
            }

            elem.appendChild(trk);
        }
    }

    private void doWriteTrackSegment(TrackSegment segment, org.w3c.dom.Element elem)
    {
        if (segment != null)
        {
            org.w3c.dom.Element trkseg = this.doc.createElement("trkseg");

            if (segment.getPoints() != null)
            {
                for (TrackPoint tp : segment.getPoints())
                    doWriteTrackPoint(tp, trkseg);
            }

            elem.appendChild(trkseg);
        }
    }

    private void doWriteTrackPoint(TrackPoint point, org.w3c.dom.Element elem)
    {
        if (point != null)
        {
            org.w3c.dom.Element trkpt = this.doc.createElement("trkpt");
            trkpt.setAttribute("lat", Double.toString(point.getLatitude()));
            trkpt.setAttribute("lon", Double.toString(point.getLongitude()));

            org.w3c.dom.Element ele = this.doc.createElement("ele");
            org.w3c.dom.Text eleText = this.doc.createTextNode(Double.toString(point.getElevation()));
            ele.appendChild(eleText);
            trkpt.appendChild(ele);

            if (point.getTime() != null)
            {
                org.w3c.dom.Element time = this.doc.createElement("time");
                org.w3c.dom.Text timeText = this.doc.createTextNode(point.getTime());
                time.appendChild(timeText);
                trkpt.appendChild(time);
            }

            elem.appendChild(trkpt);
        }
    }

    private void doFlush() throws javax.xml.transform.TransformerException
    {
        javax.xml.transform.TransformerFactory factory = javax.xml.transform.TransformerFactory.newInstance();
        javax.xml.transform.Transformer transformer = factory.newTransformer();
        javax.xml.transform.Source source = new javax.xml.transform.dom.DOMSource(this.doc);
        transformer.transform(source, this.result);
    }
}