| gvSIG desktop 1

/*

 * Created on 02-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

 */

/* CVS MESSAGES:

*

* $Id: AttributeBufferVisitor.java 5412 2006-05-24 21:15:07Z azabala $

* $Log$

* Revision 1.1  2006-05-24 21:14:41  azabala

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

*

* Revision 1.8  2006/05/01 19:18:09  azabala

* revisi?n general del buffer (a?adidos anillos concentricos, buffers interiores y exteriores, etc)

*

* Revision 1.7  2006/03/28 16:27:16  azabala

* *** empty log message ***

*

* Revision 1.6  2006/03/07 21:01:33  azabala

* *** empty log message ***

*

* Revision 1.5  2006/03/06 19:48:39  azabala

* *** empty log message ***

*

* Revision 1.2  2006/03/05 19:57:05  azabala

* *** empty log message ***

*

* Revision 1.1  2006/02/17 16:31:38  azabala

* *** empty log message ***

*

* Revision 1.3  2006/02/12 21:02:44  azabala

* *** empty log message ***

*

* Revision 1.2  2006/02/09 16:01:06  azabala

* First version in CVS

*

* Revision 1.1  2006/02/02 19:46:01  azabala

* First version in CVS

*

*

*/

package com.iver.cit.gvsig.geoprocess.buffer.fmap;

import com.hardcode.gdbms.engine.values.NumericValue;

import com.iver.cit.gvsig.fmap.DriverException;

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

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

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

import com.iver.cit.gvsig.fmap.layers.layerOperations.AlphanumericData;

import com.iver.cit.gvsig.fmap.layers.layerOperations.VectorialData;

import com.iver.cit.gvsig.fmap.operations.strategies.VisitException;

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

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

import com.vividsolutions.jts.geom.Geometry;

/**

 * FeatureVisitor that computes buffer geometries from original geometrie

 * and an attribute value of IFeature

 * @author azabala

 *

 */

public class AttributeBufferVisitor extends BufferVisitor {

        /**

         * Attribute name from which visitor will get buffer distances

         */

        private String attributeName;

        /**

         * It allows visitor to get attribute values link to geometries

         */

        private SelectableDataSource recordset;

        /**

         * Processes individual buffer results

         * (we could persist them in a datastore, caching them, etc

         */

        private GeoprocessingResultsProcessor resultProcessor;

        /**

         * Constructor

         * @param attributeName

         * @param recordset

         */

        public AttributeBufferVisitor(String attributeName) throws GeoprocessException{

                this.attributeName = attributeName;

        }

        public void stop(FLayer layer) {

                resultProcessor.finish();

        }

        public boolean start(FLayer layer) {

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

                        try {

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

                        } catch (DriverException e) {

                                return false;//must we throw an Exception??

                        }

                        return true;

                }

                return false;

        }

        public double getBufferDistance(IGeometry g, int index){

                NumericValue value = null;

                try {

                        int fieldIndex = recordset.getFieldIndexByName(attributeName);

                        //we could throw an AttributeBufferException, or

                        //we could check preconditions in BufferGeoprocess

                        //TODO to check attribute is a NUMBER

                         value = (NumericValue) recordset.

                                         getFieldValue(index, fieldIndex);

                } catch (com.hardcode.gdbms.engine.data.driver.DriverException e) {

                        return -1d;

                }

                //TODO catch ClassCastException 

                return value.doubleValue();

        }

        public String getProcessDescription() {

                return "Computing buffers applying distances from attribute";

        }

}