| gvSIG desktop 1

/*

 * Created on 10-abr-2006

 *

 * gvSIG. Sistema de Informaci?n Geogr?fica de la Generalitat Valenciana

 *

 * Copyright (C) 2004 IVER T.I. and Generalitat Valenciana.

 *

 * This program 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 2

 * of the License, or (at your option) any later version.

 *

 * This program 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 this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,USA.

 *

 * For more information, contact:

 *

 *  Generalitat Valenciana

 *   Conselleria d'Infraestructures i Transport

 *   Av. Blasco Ib??ez, 50

 *   46010 VALENCIA

 *   SPAIN

 *

 *      +34 963862235

 *   gvsig@gva.es

 *      www.gvsig.gva.es

 *

 *    or

 *

 *   IVER T.I. S.A

 *   Salamanca 50

 *   46005 Valencia

 *   Spain

 *

 *   +34 963163400

 *   dac@iver.es

 */

/* CVS MESSAGES:

*

* $Id: 

* $Log: 

*/

package org.gvsig.topology.errorfixes;

import java.util.ArrayList;

import java.util.List;

import org.gvsig.exceptions.BaseException;

import org.gvsig.fmap.core.FeatureUtil;

import org.gvsig.fmap.core.NewFConverter;

import org.gvsig.jts.JtsUtil;

import org.gvsig.topology.Messages;

import org.gvsig.topology.TopologyError;

import com.iver.cit.gvsig.fmap.core.IFeature;

import com.vividsolutions.jts.geom.Geometry;

import com.vividsolutions.jts.geom.GeometryCollection;

/**

 * Automatic fix to 'Polygon must not overlaps' topology error.

 * 

 * It removes from the two overlappings polygons their common area, leaving

 * a gap or void.

 * 

 * @author Alvaro Zabala

 *

 */

public class SubstractOverlapPolygonFix extends AbstractTopologyErrorFix {

        public List<IFeature>[] fixAlgorithm(TopologyError error) throws BaseException {

                Geometry errorJts = NewFConverter.toJtsGeometry(error.getGeometry());

                IFeature firstFeature = error.getFeature1();

                Geometry firstJts = NewFConverter.toJtsGeometry(firstFeature.getGeometry());

                IFeature secondFeature = error.getFeature2();

                Geometry secondJts = NewFConverter.toJtsGeometry(secondFeature.getGeometry());

                List<IFeature> editedFeatures = new ArrayList<IFeature>();

                //we could find three cases:

                //a) first covers second, we compute first difference second

                //b) they dont cover or are covered. we compute first difference second

                //c) second covers a, we compute second difference first, and modifies second

                if(secondJts.covers(firstJts)){

                        //we remove the overlapped area from the container geometry

                        secondFeature = FeatureUtil.removeOverlappingArea(secondFeature, 

                                                                                                                        secondJts, 

                                                                                                                        errorJts );

                        editedFeatures.add(secondFeature);

                }else if(secondJts.coveredBy(firstJts))

                {

                        //we remove secondJts from firstJts

                        firstFeature = FeatureUtil.removeOverlappingArea(firstFeature, 

                                        firstJts, 

                                        errorJts );

                        editedFeatures.add(firstFeature);

                }else{

                        //we remove overlapping area from both features

                        firstFeature = FeatureUtil.removeOverlappingArea(firstFeature, 

                                        firstJts, 

                                        errorJts );

                        secondFeature = FeatureUtil.removeOverlappingArea(secondFeature, 

                                        secondJts, 

                                        errorJts );

                        editedFeatures.add(secondFeature);

                        editedFeatures.add(firstFeature);

                }

                return (List<IFeature>[]) new List[]{editedFeatures};

        }

        public String getEditionDescription() {

                return Messages.getText("SUBSTRACT_OVERLAP_AREA_FIX");

        }

}