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.lang.reflect.InvocationTargetException;
008import java.util.Collection;
009
010import javax.swing.SwingUtilities;
011
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.ExceptionDialogUtil;
016import org.openstreetmap.josm.gui.MainApplication;
017import org.openstreetmap.josm.gui.PleaseWaitRunnable;
018import org.openstreetmap.josm.gui.layer.OsmDataLayer;
019import org.openstreetmap.josm.gui.progress.ProgressMonitor;
020import org.openstreetmap.josm.io.MultiFetchServerObjectReader;
021import org.openstreetmap.josm.io.OsmTransferException;
022import org.openstreetmap.josm.tools.CheckParameterUtil;
023import org.openstreetmap.josm.tools.Logging;
024import org.xml.sax.SAXException;
025
026/**
027 * The asynchronous task for fully downloading a collection of relations. Does a full download
028 * for each relations and merges the relation into an {@link OsmDataLayer}
029 * @since 2563
030 */
031public class DownloadRelationTask extends PleaseWaitRunnable {
032    private boolean canceled;
033    private Exception lastException;
034    private final Collection<Relation> relations;
035    private final OsmDataLayer layer;
036    private MultiFetchServerObjectReader multiObjectReader;
037
038    /**
039     * Creates the download task
040     *
041     * @param relations a collection of relations. Must not be null.
042     * @param layer the layer which data is to be merged into
043     * @throws IllegalArgumentException if relations is null
044     * @throws IllegalArgumentException if layer is null
045     */
046    public DownloadRelationTask(Collection<Relation> relations, OsmDataLayer layer) {
047        super(tr("Download relations"), false /* don't ignore exception */);
048        CheckParameterUtil.ensureParameterNotNull(relations, "relations");
049        CheckParameterUtil.ensureParameterNotNull(layer, "layer");
050        this.relations = relations;
051        this.layer = layer;
052        if (!layer.isDownloadable()) {
053            throw new IllegalArgumentException("Non-downloadable layer: " + layer);
054        }
055    }
056
057    @Override
058    protected void cancel() {
059        canceled = true;
060        synchronized (this) {
061            if (multiObjectReader != null) {
062                multiObjectReader.cancel();
063            }
064        }
065    }
066
067    @Override
068    protected void finish() {
069        if (canceled)
070            return;
071        if (lastException != null) {
072            ExceptionDialogUtil.explainException(lastException);
073        }
074    }
075
076    @Override
077    protected void realRun() throws SAXException, IOException, OsmTransferException {
078        try {
079            final DataSet allDownloads = new DataSet();
080            getProgressMonitor().setTicksCount(relations.size());
081            DataSet dataSet = null;
082            synchronized (this) {
083                if (canceled)
084                    return;
085                multiObjectReader = MultiFetchServerObjectReader.create();
086                multiObjectReader.setRecurseDownRelations(true).setRecurseDownAppended(false);
087                multiObjectReader.append(relations);
088                dataSet = multiObjectReader.parseOsm(progressMonitor.createSubTaskMonitor(ProgressMonitor.ALL_TICKS, false));
089            }
090            if (dataSet == null)
091                return;
092            synchronized (this) {
093                if (canceled)
094                    return;
095            }
096            new DataSetMerger(allDownloads, dataSet).merge();
097            SwingUtilities.invokeAndWait(() -> {
098                layer.mergeFrom(allDownloads);
099                layer.onPostDownloadFromServer();
100                MainApplication.getMap().repaint();
101            });
102        } catch (OsmTransferException | InvocationTargetException | InterruptedException e) {
103            if (canceled) {
104                Logging.warn(tr("Ignoring exception because task was canceled. Exception: {0}", e.toString()));
105                return;
106            }
107            lastException = e;
108        }
109    }
110}