Application: gvSIG desktop » gvSIG geoprocess

/*

 * Created on 16-feb-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

 */

package org.gvsig.sextante.app.algorithm.clip;

import org.gvsig.sextante.app.algorithm.base.util.GeometryUtil;

import org.gvsig.sextante.app.algorithm.base.visitor.exception.ProcessVisitorException;

import org.gvsig.sextante.app.algorithm.base.visitor.exception.StartVisitorException;

import org.gvsig.sextante.app.algorithm.base.visitor.exception.VisitorException;

import com.vividsolutions.jts.geom.Geometry;

/**

 * This class analyzes all features of a layer, clipping its geometries

 * with the convex hull of another layer.

 * If the geometry of the feature analyzed doesnt intersect with the convex

 * hull geometry, the clipvisitor will ignore it.

 *

 * It intersects, computes intersection and creates a new feature with

 * the same attributes and the new intersection geometry.

 * @author azabala

 *

 */

public class ClipVisitor implements FeatureVisitor {

        /**

         * Clipping geometry: the convex hull of the

         * clipping layer

         */

        private Geometry clippingConvexHull;

        /**

         * It allows visitor to get attribute values link to geometries

         */

        private SelectableDataSource recordset;

        /**

         * Processes individual clip results

         */

        private FeaturePersisterProcessor resultProcessor;

        /**

         * If its different of null manages user selection (discarting any

         * feature else)

         */

        private FBitSet selection;

        /**

         * Constructor. It requires clipping geometry.

         * @param clippingGeometry

         */

        public ClipVisitor(Geometry clippingGeometry,

                                ITableDefinition layerDefinition,

                                ISchemaManager schemaManager,

                                IWriter writer){

                this.clippingConvexHull = clippingGeometry;

                        try {

                                this.resultProcessor = new FeaturePersisterProcessor(layerDefinition,

                                                schemaManager,writer);

                        } catch (SchemaEditionException e) {

                                // TODO Auto-generated catch block

                                e.printStackTrace();

                        } catch (VisitorException e) {

                                // TODO Auto-generated catch block

                                e.printStackTrace();

                        }

        }

        public void setSelection(FBitSet selection){

                this.selection = selection;

        }

        /**

         * clips feature's geometry with the clipping geometry, preserving

         * feature's original attributes.

         * If feature's geometry doesnt touch clipping geometry, it will be

         * ignored.

         */

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

                //TODO METER EL PRINCIPIO Y EL FINAL EN EL VISITOR ABSTRACTO

                //AS�, TENDRIAMOS LA GESTI�N TOPOL�GICA EN CADA VISITOR

                if(g == null)

                        return;

                if(selection != null){

                        if(!selection.get(index))

                                return;

                }

                Geometry jtsGeom = g.toJTSGeometry();

                if(!jtsGeom.getEnvelope().intersects(clippingConvexHull.getEnvelope()))

                        return;

                if(jtsGeom.intersects(clippingConvexHull)){

                        try{

                                Geometry newGeom = jtsGeom.intersection(clippingConvexHull);

                                resultProcessor.processJtsGeometry(newGeom, index);

                        }catch(com.vividsolutions.jts.geom.TopologyException e){

                                e.printStackTrace();

                                System.out.println(jtsGeom.toText());

                                System.out.println(clippingConvexHull.toText());

                                /*

                                 * TODO En este caso, la de recorte chequearla al principio

                                 * (cuando se calcula) y solo chequearemos las de entrada

                                 * conforme nos van viniendo.

                                 *

                                 * HAY QUE CREAR UN FRAMEWORK DE CORRECCI�N TOPOL�GICA DE

                                 * GEOMETRIAS:

                                 * -Mirando autointersecciones.

                                 * -Mirando duplicados.

                                 * -Eliminando colineales.

                                 * ETC.

                                 * */

                                if(! jtsGeom.isValid()){

                                        System.out.println("La geometria de entrada no es valida");

                                        jtsGeom = GeometryUtil.removeDuplicatesFrom(jtsGeom);

                                }

                                if(! clippingConvexHull.isValid()){

                                        System.out.println("La geometria de recorte no es valida");

                                        clippingConvexHull = GeometryUtil.removeDuplicatesFrom(clippingConvexHull);

                                }

                                try{

                                        Geometry newGeom = jtsGeom.intersection(clippingConvexHull);

                                        resultProcessor.processJtsGeometry(newGeom, index);

                                }catch(com.vividsolutions.jts.geom.TopologyException ee){

                                        ee.printStackTrace();

                                } catch (ReadDriverException ee) {

                                        // TODO Auto-generated catch block

                                        ee.printStackTrace();

                                };

                        } catch (ReadDriverException e) {

                                // TODO Auto-generated catch block

                                e.printStackTrace();

                        }

                }//if

        }

        public void stop(FLayer layer) throws VisitorException {

                resultProcessor.finish();

        }

        public boolean start(FLayer layer) throws StartVisitorException {

                if(layer instanceof AlphanumericData && layer instanceof VectorialData){

                        try {

                                this.recordset = ((AlphanumericData)layer).getRecordset();

                                this.resultProcessor.setSelectableDataSource(recordset);

                        } catch (ReadDriverException e) {

                                return false;

                        }

                        return true;

                }

                return false;

        }

        public SelectableDataSource getRecordset() {

                return recordset;

        }

        public void setRecordset(SelectableDataSource recordset) {

                this.recordset = recordset;

        }

        public String getProcessDescription() {

                return "Clipping features agaisnt a clip geometry";

        }

}