Application: gvSIG desktop

/*

 * Created on 02-may-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: SpatiallyIndexedSpatialJoinVisitor.java 10626 2007-03-06 16:55:54Z caballero $

 * $Log$

 * Revision 1.2  2007-03-06 16:47:58  caballero

 * Exceptions

 *

 * Revision 1.1  2006/06/20 18:20:45  azabala

 * first version in cvs

 *

 * Revision 1.2  2006/06/02 18:21:28  azabala

 * *** empty log message ***

 *

 * Revision 1.1  2006/05/24 21:09:47  azabala

 * primera version en cvs despues de refactoring orientado a crear un framework extensible de geoprocessing

 *

 * Revision 1.1  2006/05/02 18:58:47  azabala

 * first version in cvs

 *

 *

 */

package com.iver.cit.gvsig.geoprocess.impl.spatialjoin.fmap;

import java.awt.geom.Rectangle2D;

import java.util.List;

import com.hardcode.gdbms.driver.exceptions.ReadDriverException;

import com.hardcode.gdbms.engine.data.driver.DriverException;

import com.iver.cit.gvsig.exceptions.expansionfile.ExpansionFileReadException;

import com.iver.cit.gvsig.exceptions.visitors.ProcessVisitorException;

import com.iver.cit.gvsig.exceptions.visitors.VisitorException;

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

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

import com.iver.cit.gvsig.fmap.layers.FLyrVect;

import com.iver.cit.gvsig.fmap.layers.ReadableVectorial;

import com.iver.cit.gvsig.fmap.spatialindex.INearestNeighbourFinder;

import com.iver.cit.gvsig.fmap.spatialindex.ISpatialIndex;

import com.iver.cit.gvsig.geoprocess.core.fmap.FeatureProcessor;

import com.vividsolutions.jts.geom.Geometry;

/**

 * This visitor does spatial join with nearest neighbour criteria by using an

 * spatial index with nearest neighbour searching capabilities.<br>

 * By now, RTreeSptLib is the only spatial index that is also a

 * INearestNeigbourFinder implementation. <br>

 *

 * @author azabala

 *

 */

public class SpatiallyIndexedSpatialJoinVisitor extends

                NearestSpatialJoinVisitor {

        /**

         * Geometry.distance() is a costly operation. Thats the reason for we are

         * only using a nearest neighbour. TODO SpatialIndex works with Rectangle2D,

         * and this may be a simplification that drives to errors. Make aditional

         * probes to use a number of default neighbours

         */

        static final int DEFAULT_NUM_NEIGBOURS = 1;

        /**

         * Number of neighbours that nearestFinder must found.

         */

        int numOfNeighbours = DEFAULT_NUM_NEIGBOURS;

        /**

         * Spetialized instance in nearest neighbour searchs.

         */

        private INearestNeighbourFinder nearestFinder;

        /**

         * Constructor

         *

         * @param sourceLayer

         * @param targetLayer

         * @param processor

         * @throws DriverException

         */

        public SpatiallyIndexedSpatialJoinVisitor(FLyrVect sourceLayer,

                        FLyrVect targetLayer, FeatureProcessor processor)

                        throws ReadDriverException {

                super(sourceLayer, targetLayer, processor);

                // lo comentamos porque debe ser llamado externamente

                // initialize();

        }

        public void initialize() {

                ISpatialIndex spatialIndex = targetLayer.getISpatialIndex();

                if (spatialIndex instanceof INearestNeighbourFinder)

                        nearestFinder = (INearestNeighbourFinder) spatialIndex;

                else

                        throw new IllegalArgumentException(

                                        "La segunda capa de spatial join ha de tener un ?ndice espacial de tipo INearestNeighbourFinder para usar este visitor");

        }

        /**

         * Processes a Feature of source layer, looking for its nearest feature of

         * target layer and taking attributes from it

         */

        public void visit(IGeometry g, int sourceIndex) throws VisitorException, ProcessVisitorException {

                if (g == null)

                        return;

                try {

                        // no se si el rtree har? la busqueda bien si el rectangulo

                        // de busqueda no est? insertado. Hacer las pruebas (si no,

                        // a?adimos ahora y borramos luego)

                        Geometry gJts = g.toJTSGeometry();

                        Rectangle2D rect = g.getBounds2D();

                        List nearestLst = nearestFinder.findNNearest(numOfNeighbours, rect);

                        int targetIndex = -1;// index of nearest neighbour

                        double nearestDistance = Double.MAX_VALUE;

                        ReadableVectorial rv = targetLayer.getSource();

                        for (int i = 0; i < nearestLst.size(); i++) {

                                int index2 = ((Integer) nearestLst.get(i)).intValue();

                                IGeometry g2 = rv.getShape(index2);

                                Geometry g2Jts = g2.toJTSGeometry();

                                double dist = gJts.distance(g2Jts);

                                if (dist <= nearestDistance) {

                                        // by adding <=, we follow the convention that

                                        // if two features are at the same distance, take

                                        // the last as nearest neighbour

                                        nearestDistance = dist;

                                        targetIndex = index2;

                                }// if

                        }// for

                        if (targetIndex == -1)

                                throw new ProcessVisitorException(targetRecordset.getName(),null,

                                                "Problemas durante el spatial join, no se encontr? un vecino mas proximo");

                        IFeature joinedFeature = createFeature(g, sourceIndex, targetIndex,

                                        nearestDistance);

                        this.featureProcessor.processFeature(joinedFeature);

                } catch (ReadDriverException e) {

                        throw new ProcessVisitorException(targetRecordset.getName(),e,

                                        "Error de driver al escribir un feature resultante de un spatial join");

                } catch (ExpansionFileReadException e) {

                        throw new ProcessVisitorException(targetRecordset.getName(),e,

                                "Error de driver al escribir un feature resultante de un spatial join");

                }

        }

}