001// License: GPL. For details, see LICENSE file.
002package org.openstreetmap.josm.gui.dialogs.relation;
003
004import static org.openstreetmap.josm.tools.I18n.tr;
005
006import java.io.IOException;
007import java.util.Collection;
008
009import javax.swing.SwingUtilities;
010
011import org.openstreetmap.josm.Main;
012import org.openstreetmap.josm.data.osm.DataSet;
013import org.openstreetmap.josm.data.osm.DataSetMerger;
014import org.openstreetmap.josm.data.osm.Relation;
015import org.openstreetmap.josm.gui.DefaultNameFormatter;
016import org.openstreetmap.josm.gui.ExceptionDialogUtil;
017import org.openstreetmap.josm.gui.PleaseWaitRunnable;
018import org.openstreetmap.josm.gui.layer.OsmDataLayer;
019import org.openstreetmap.josm.io.OsmServerObjectReader;
020import org.openstreetmap.josm.io.OsmTransferException;
021import org.openstreetmap.josm.tools.CheckParameterUtil;
022import 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 */
029public class DownloadRelationTask extends PleaseWaitRunnable {
030    private boolean canceled;
031    private Exception lastException;
032    private final Collection<Relation> relations;
033    private final 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 if relations is null
042     * @throws IllegalArgumentException if layer is null
043     */
044    public DownloadRelationTask(Collection<Relation> relations, OsmDataLayer layer) {
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(),
080                        relation.getDisplayName(DefaultNameFormatter.getInstance())));
081                synchronized (this) {
082                    if (canceled) return;
083                    objectReader = new OsmServerObjectReader(relation.getPrimitiveId(), true /* full download */);
084                }
085                DataSet dataSet = objectReader.parseOsm(
086                        getProgressMonitor().createSubTaskMonitor(0, false)
087                );
088                if (dataSet == null)
089                    return;
090                synchronized (this) {
091                    if (canceled) return;
092                    objectReader = null;
093                }
094                DataSetMerger merger = new DataSetMerger(allDownloads, dataSet);
095                merger.merge();
096                getProgressMonitor().worked(1);
097            }
098
099            SwingUtilities.invokeAndWait(
100                    new Runnable() {
101                        @Override
102                        public void run() {
103                            layer.mergeFrom(allDownloads);
104                            layer.onPostDownloadFromServer();
105                            Main.map.repaint();
106                        }
107                    }
108            );
109        } catch (Exception e) {
110            if (canceled) {
111                Main.warn(tr("Ignoring exception because task was canceled. Exception: {0}", e.toString()));
112                return;
113            }
114            lastException = e;
115        }
116    }
117}