001    // License: GPL. For details, see LICENSE file.
002    package org.openstreetmap.josm.gui.dialogs.relation;
003    
004    import static org.openstreetmap.josm.tools.I18n.tr;
005    
006    import java.io.IOException;
007    import java.util.Collection;
008    
009    import javax.swing.SwingUtilities;
010    
011    import org.openstreetmap.josm.Main;
012    import org.openstreetmap.josm.data.osm.DataSet;
013    import org.openstreetmap.josm.data.osm.DataSetMerger;
014    import org.openstreetmap.josm.data.osm.Relation;
015    import org.openstreetmap.josm.gui.DefaultNameFormatter;
016    import org.openstreetmap.josm.gui.ExceptionDialogUtil;
017    import org.openstreetmap.josm.gui.PleaseWaitRunnable;
018    import org.openstreetmap.josm.gui.layer.OsmDataLayer;
019    import org.openstreetmap.josm.io.OsmServerObjectReader;
020    import org.openstreetmap.josm.io.OsmTransferException;
021    import org.openstreetmap.josm.tools.CheckParameterUtil;
022    import org.xml.sax.SAXException;
023    
024    /**
025     * The asynchronous task for fully downloading a collection of relations. Does a full download
026     * for each relations and merges the relation into an {@link OsmDataLayer}
027     *
028     */
029    public class DownloadRelationTask extends PleaseWaitRunnable {
030        private boolean canceled;
031        private Exception lastException;
032        private Collection<Relation> relations;
033        private OsmDataLayer layer;
034        private OsmServerObjectReader objectReader;
035    
036        /**
037         * Creates the download task
038         *
039         * @param relations a collection of relations. Must not be null.
040         * @param layer the layer which data is to be merged into
041         * @throws IllegalArgumentException thrown if relations is null
042         * @throws IllegalArgumentException thrown if layer is null
043         */
044        public DownloadRelationTask(Collection<Relation> relations, OsmDataLayer layer) throws IllegalArgumentException{
045            super(tr("Download relations"), false /* don't ignore exception */);
046            CheckParameterUtil.ensureParameterNotNull(relations, "relations");
047            CheckParameterUtil.ensureParameterNotNull(layer, "layer");
048            this.relations = relations;
049            this.layer = layer;
050        }
051    
052        @Override
053        protected void cancel() {
054            canceled = true;
055            synchronized(this) {
056                if (objectReader != null) {
057                    objectReader.cancel();
058                }
059            }
060        }
061    
062        @Override
063        protected void finish() {
064            if (canceled)
065                return;
066            if (lastException != null) {
067                ExceptionDialogUtil.explainException(lastException);
068            }
069        }
070    
071        @Override
072        protected void realRun() throws SAXException, IOException, OsmTransferException {
073            try {
074                final DataSet allDownloads = new DataSet();
075                int i=0;
076                getProgressMonitor().setTicksCount(relations.size());
077                for (Relation relation: relations) {
078                    i++;
079                    getProgressMonitor().setCustomText(tr("({0}/{1}): Downloading relation ''{2}''...", i,relations.size(),relation.getDisplayName(DefaultNameFormatter.getInstance())));
080                    synchronized (this) {
081                        if (canceled) return;
082                        objectReader = new OsmServerObjectReader(relation.getPrimitiveId(), true /* full download */);
083                    }
084                    DataSet dataSet = objectReader.parseOsm(
085                            getProgressMonitor().createSubTaskMonitor(0, false)
086                    );
087                    if (dataSet == null)
088                        return;
089                    synchronized (this) {
090                        if (canceled) return;
091                        objectReader = null;
092                    }
093                    DataSetMerger merger = new DataSetMerger(allDownloads, dataSet);
094                    merger.merge();
095                    getProgressMonitor().worked(1);
096                }
097    
098                SwingUtilities.invokeAndWait(
099                        new Runnable() {
100                            public void run() {
101                                layer.mergeFrom(allDownloads);
102                                layer.onPostDownloadFromServer();
103                                Main.map.repaint();
104                            }
105                        }
106                );
107            } catch (Exception e) {
108                if (canceled) {
109                    System.out.println(tr("Warning: Ignoring exception because task was canceled. Exception: {0}", e
110                            .toString()));
111                    return;
112                }
113                lastException = e;
114            }
115        }
116    }