PolyExporter.java

// License: GPL. For details, see LICENSE file.
package poly;

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.TreeMap;

import org.openstreetmap.josm.data.osm.DataSet;
import org.openstreetmap.josm.data.osm.Node;
import org.openstreetmap.josm.data.osm.OsmPrimitive;
import org.openstreetmap.josm.data.osm.Relation;
import org.openstreetmap.josm.data.osm.RelationMember;
import org.openstreetmap.josm.data.osm.Way;
import org.openstreetmap.josm.gui.layer.Layer;
import org.openstreetmap.josm.gui.layer.OsmDataLayer;
import org.openstreetmap.josm.io.OsmExporter;

/**
 * Writes poly files.
 *
 * @author zverik
 */
public class PolyExporter extends OsmExporter {

    public PolyExporter() {
        super(PolyType.FILE_FILTER);
    }

    @Override
    public void exportData(File file, Layer layer) throws IOException {
        if (layer instanceof OsmDataLayer) {
            try (BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file), "UTF8"))) {
                DataSet ds = ((OsmDataLayer) layer).data;
                Map<Way, Boolean> ways = new TreeMap<>();
                String polygonName = file.getName();
                if (polygonName.indexOf('.') > 0)
                    polygonName = polygonName.substring(0, polygonName.indexOf('.'));
                for (Way w : ds.getWays()) {
                    if (w.isClosed()) {
                        boolean outer = isOuter(w);
                        ways.put(w, outer);
                        if (w.hasKey("name"))
                            polygonName = w.get("name").replace("\n", " ");
                    }
                }
                ways = sortOuterInner(ways);

                int counter = 1;
                writer.write(polygonName);
                writer.newLine();
                for (Way w : ways.keySet()) {
                    if (!ways.get(w))
                        writer.write('!');
                    writer.write(String.valueOf(counter++));
                    writer.newLine();
                    for (Node n : w.getNodes()) {
                        writer.write(String.format(Locale.ENGLISH, "   %f   %f", n.getCoor().lon(), n.getCoor().lat()));
                        writer.newLine();
                    }
                    writer.write("END");
                    writer.newLine();
                }
                writer.write("END");
                writer.newLine();
            }
        }
    }

    private boolean isOuter(Way w) {
        for (OsmPrimitive p : w.getReferrers()) {
            if (p instanceof Relation && ((Relation) p).isMultipolygon()) {
                for (RelationMember m : ((Relation) p).getMembers()) {
                    if (m.refersTo(w) && "inner".equals(m.getRole())) {
                        return false;
                    }
                }
            }
        }
        return true;
    }

    private Map<Way, Boolean> sortOuterInner(Map<Way, Boolean> ways) {
        LinkedHashMap<Way, Boolean> result = new LinkedHashMap<>(ways.size());
        List<Way> inner = new ArrayList<>();
        for (Way w : ways.keySet()) {
            Boolean outer = ways.get(w);
            if (outer)
                result.put(w, outer);
            else
                inner.add(w);
        }
        for (Way w : inner) {
            result.put(w, Boolean.FALSE);
        }
        return result;
    }
}