Application: gvSIG desktop

/*

 * Created on 11-abr-2007

 *

 * 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: DefaultFeatureIterator.java 14713 2007-10-18 07:06:07Z jdominguez $

* $Log$

* Revision 1.5  2007-09-19 16:25:04  jaume

* ReadExpansionFileException removed from this context

*

* Revision 1.4  2007/06/07 11:49:39  azabala

* added default constructor

*

* Revision 1.3  2007/06/07 10:19:56  azabala

* closeIterator calls to ReadableVectorial.stop

*

* Revision 1.2  2007/06/06 18:03:34  azabala

* when String[] param is null, instead of return all fields it returns zero fields

*

* Revision 1.1  2007/05/29 19:08:11  azabala

* first version in cvs

*

* Revision 1.1  2007/04/19 17:27:58  azabala

* first version in cvs

*

*

*/

package com.iver.cit.gvsig.fmap.drivers.featureiterators;

import org.cresques.cts.ICoordTrans;

import org.cresques.cts.IProjection;

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

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

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

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

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

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

import com.iver.cit.gvsig.fmap.drivers.IFeatureIterator;

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

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

/**

 * 

 * Iterator over all the features of a vectorial adapter.

 * It is thinked for data sources which dont have capabilities

 * of querying or reprojection.

 * 

 * 

 * @author Alvaro Zabala

 * */

public class DefaultFeatureIterator implements IFeatureIterator {

        /**

         * Projection of the layer on which this iterator iterates.

         * TODO Move projection from layer to adapter or driver

         * */

        protected IProjection sourceProjection;

    /**

     * If its setted, all features returned by this iterator

     * will be previously reprojected to this target projection

     */

        protected IProjection targetProjection;

        /**

         * If its setted, returned features only will have these alphanumeric attributes

         */

        protected String[] fieldNames;

        /**

         * vectorial data source. It reads geometries

         * and has the recordset

         */

        protected ReadableVectorial source;

        /**

         * recordset, it reads alphanumeric attributes

         */

        protected SelectableDataSource recordset;

        /**

         * index of the next feature that will be returned by this

         * iterator

         */

        protected int currentFeature;

        /**

         * Default constructor. 

         * Creates an iterator which will return features in the data source projection

         * (without reprojection) and with all the alphanumeric attributes

         * @throws ReadDriverException 

         *

         */

        public DefaultFeatureIterator( ReadableVectorial source) throws ReadDriverException{

                this.source = source;

                //needed for layers in edition status

                this.source.start();

                this.recordset = source.getRecordset();

                currentFeature = 0;

        }

        /**

         * Constructor.

         * The iterator will reproject the geometry of the features to the specified target projection,

         * and with the specified attribute fields.

         * */

        public DefaultFeatureIterator(ReadableVectorial source, 

                                                                        IProjection sourceProj, 

                                                                        IProjection targetProj, 

                                                                        String[] fieldNames) throws ReadDriverException{

                this(source);

                this.sourceProjection = sourceProj;

                //check to avoid reprojections with the same projection

                if(targetProj != null){

                         // FJP: Si la capa original no sabemos qu? proyecci?n tiene, no hacemos nada

                        if (sourceProj != null) {

                                if(!(targetProj.getAbrev().equalsIgnoreCase(sourceProjection.getAbrev())))

                                        this.targetProjection = targetProj;

                        }

                }

                this.fieldNames = fieldNames;

        }

        /**

         * Default constructor.

         *

         */

        public DefaultFeatureIterator(){

        }

        public boolean hasNext() throws ReadDriverException {

                boolean bMore = (currentFeature < source.getShapeCount());

                return bMore;

        }

        public IFeature next() throws ReadDriverException {

                try {

                        IGeometry geom = source.getShape(currentFeature);

                        reprojectIfNecessary(geom);

                        Value[] regAtt = getValues(currentFeature);

                        IFeature feat  = new DefaultFeature(geom, regAtt, currentFeature + "");

                        currentFeature++;

                        return feat;

                } catch (ExpansionFileReadException e) {

                        throw new ReadDriverException("",e);

                } 

        }

        public void closeIterator() throws ReadDriverException {

                this.source.stop();

        }

        public String[] getFieldNames() {

                return fieldNames;

        }

        public void setFieldNames(String[] fieldNames) {

                this.fieldNames = fieldNames;

        }

        public IProjection getTargetProjection() {

                return targetProjection;

        }

        public void setTargetProjection(IProjection targetProjection) {

                this.targetProjection = targetProjection;

        }

        public IProjection getSourceProjection() {

                return sourceProjection;

        }

        public void setSourceProjection(IProjection sourceProjection) {

                this.sourceProjection = sourceProjection;

        }

        /**

         * 

         * Checks if must reproject the given geom

         * and reprojects it if true

         * @param geom

         */

        protected void reprojectIfNecessary(IGeometry geom){

                if(this.targetProjection != null && 

                   this.sourceProjection != null &&

                   this.targetProjection.getAbrev() != this.sourceProjection.getAbrev()){

                        ICoordTrans trans = sourceProjection.getCT(targetProjection);

                        geom.reProject(trans);

                }

        }

        protected Value[] getValues(int featureIdx) throws ReadDriverException{

                Value[] regAtt = null;

                if(fieldNames == null){

                        //TODO Duda: cual es el comportamiento deseado cuando fieldNames sea null

                        //devolverlo todo o no devolver nada?????

//                        regAtt = new Value[recordset.getFieldCount()];//igual optimiza reutilizar y hacer copias (en vez de alocar array)

//                        for (int fieldId = 0; fieldId < recordset.getFieldCount(); fieldId++) {

//                                regAtt[fieldId] = recordset.getFieldValue(featureIdx, fieldId);

//                        }

                        regAtt = new Value[0];

                }else{

                        regAtt = new Value[fieldNames.length];

                        for (int fieldId = 0; fieldId < fieldNames.length; fieldId++) {

                                int fieldCode = recordset.getFieldIndexByName(fieldNames[fieldId]);

                                regAtt[fieldId] = recordset.getFieldValue(featureIdx, fieldCode);

                        }

                }

                return regAtt;

        }

}