eu.limetri.client.mapviewer.swing.jxmap.map.AbstractLineDrawingContext Maven / Gradle / Ivy

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/**
 *  Copyright (C) 2008-2013 LimeTri. All rights reserved.
 *
 *  AgroSense is free software: you can redistribute it and/or modify it under
 *  the terms of the GNU General Public License as published by the Free Software
 *  Foundation, either version 3 of the License, or (at your option) any later
 *  version.
 *
 *  There are special exceptions to the terms and conditions of the GPLv3 as it
 *  is applied to this software, see the FLOSS License Exception
 *  .
 *
 *  AgroSense is distributed in the hope that it will be useful, but WITHOUT ANY
 *  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 *  A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along with
 *  AgroSense. If not, see .
 */
package eu.limetri.client.mapviewer.swing.jxmap.map;


import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.CoordinateSequence;
import com.vividsolutions.jts.geom.GeometryFactory;
import com.vividsolutions.jts.geom.LineString;
import com.vividsolutions.jts.geom.impl.CoordinateArraySequence;

import eu.limetri.client.mapviewer.api.SingleObjectLayer;
import eu.limetri.client.mapviewer.data.GeoPosition;
import eu.limetri.client.mapviewer.swing.JXMapViewer;


/**
 *
 * @author johan
 */
public abstract class AbstractLineDrawingContext extends AbstractDrawingContext {
    // FIXME: set WGS-84 SRID or CRS on factory
    protected final GeometryFactory geometryFactory = new GeometryFactory();
    private SingleObjectLayer layer;

    public AbstractLineDrawingContext(SingleObjectLayer layer, JXMapViewer mapViewer) {
        super(mapViewer);
        this.layer = layer;
    }
    
    @Override
    public SingleObjectLayer getLayer(){
        return this.layer;
    }

    @Override
    protected boolean addPoint(GeoPosition position) {
        Coordinate coord = new Coordinate(position.getLongitude(), position.getLatitude());

        if (isValidLine(coord)) {
            coords.add(coord);
            pointAdded();
            // notify panel & toolbar actions:
            getPropertyChangeSupport().firePropertyChange(PROP_DRAWING_CONTEXT, null, null);
            return true;
        }
        
        return false;
    }    
    
    /**
     * Check if adding the provided coordinate to the list will produce a valid line.
     * The new segment must not intersect any of the existing ones.
     * 
     * @param coord
     * @return 
     */
    protected boolean isValidLine(Coordinate coord) {
        int len = coords.size();
        
        // number of points in LineString must be 0 or >= 2)
        if (len < 2) {
            return true;
        }
        
        CoordinateSequence coordSequence1 = new CoordinateArraySequence(coords.toArray(new Coordinate[len]));
        CoordinateSequence coordSequence2 = new CoordinateArraySequence(new Coordinate[] {coords.get(len - 1), coord});
        LineString lineString1 = new LineString(coordSequence1, geometryFactory);
        LineString lineString2 = new LineString(coordSequence2, geometryFactory);

        return !lineString1.crosses(lineString2);
    }
    
}