001    // License: GPL. For details, see LICENSE file.
002    package org.openstreetmap.josm.io.session;
003    
004    import static org.openstreetmap.josm.tools.I18n.tr;
005    
006    import java.io.IOException;
007    import java.io.InputStream;
008    
009    import javax.xml.xpath.XPath;
010    import javax.xml.xpath.XPathConstants;
011    import javax.xml.xpath.XPathExpression;
012    import javax.xml.xpath.XPathExpressionException;
013    import javax.xml.xpath.XPathFactory;
014    
015    import org.openstreetmap.josm.gui.layer.Layer;
016    import org.openstreetmap.josm.gui.progress.ProgressMonitor;
017    import org.openstreetmap.josm.io.GpxImporter;
018    import org.openstreetmap.josm.io.IllegalDataException;
019    import org.w3c.dom.Element;
020    
021    public class GpxTracksSessionImporter implements SessionLayerImporter {
022    
023        @Override
024        public Layer load(Element elem, SessionReader.ImportSupport support, ProgressMonitor progressMonitor) throws IOException, IllegalDataException {
025            String version = elem.getAttribute("version");
026            if (!"0.1".equals(version)) {
027                throw new IllegalDataException(tr("Version ''{0}'' of meta data for gpx track layer is not supported. Expected: 0.1", version));
028            }
029            try {
030                XPathFactory xPathFactory = XPathFactory.newInstance();
031                XPath xpath = xPathFactory.newXPath();
032                XPathExpression fileExp = xpath.compile("file/text()");
033                String fileStr = (String) fileExp.evaluate(elem, XPathConstants.STRING);
034                if (fileStr == null || fileStr.equals("")) {
035                    throw new IllegalDataException(tr("File name expected for layer no. {0}", support.getLayerIndex()));
036                }
037    
038                GpxImporter importer = new GpxImporter();
039                InputStream in = support.getInputStream(fileStr);
040                GpxImporter.GpxImporterData importData = importer.loadLayers(in, support.getFile(fileStr), support.getLayerName(), null, progressMonitor);
041    
042                support.addPostLayersTask(importData.getPostLayerTask());
043                return importData.getGpxLayer();
044    
045            } catch (XPathExpressionException e) {
046                throw new RuntimeException(e);
047            }
048        }
049    
050    }