Application: gvSIG desktop

/*

 * Created on 21-mar-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: GenericDissolveVisitor.java 4571 2006-03-23 21:07:32Z azabala $

* $Log$

* Revision 1.2  2006-03-23 21:03:45  azabala

* *** empty log message ***

*

* Revision 1.1  2006/03/21 19:27:38  azabala

* *** empty log message ***

*

*

*/

package com.iver.gvsig.geoprocessing.impl.dissolve;

import java.awt.geom.Rectangle2D;

import java.util.ArrayList;

import java.util.List;

import java.util.Stack;

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

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

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

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

import com.iver.cit.gvsig.fmap.core.v02.FConverter;

import com.iver.cit.gvsig.fmap.edition.EditionException;

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

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

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

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.FeatureVisitor;

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

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

import com.iver.gvsig.geoprocessing.model.FeatureProcessor;

import com.vividsolutions.jts.geom.Geometry;

import com.vividsolutions.jts.geom.GeometryFactory;

public class GenericDissolveVisitor implements FeatureVisitor {

        /**

         * Allows to get attributes of disolved layer features

         */

        SelectableDataSource recordset;

        /**

         * Is used to do spatial querys (looking for adjacent polygons to visited

         * feature geometry

         */

        FLyrVect dissolvedLayer;

        /**

         * It marks all features that have already been dissolved (to avoid process

         * them in subsecuent steps)

         * 

         */

        FBitSet dissolvedGeometries;

        /**

         * Processes results of dissolve operations (save them in a file, or cache

         * them in memory, etc)

         */

        FeatureProcessor featureProcessor;

        /**

         * Strategy to make queries to first layer

         */

        Strategy strategy;

        /**

         * Visitor to looks for adjacent features to a given feature

         */

        IndividualGeometryDissolveVisitor visitor = null;

        /**

         * Constructor

         * 

         * @param layerToDissolve

         */

        public GenericDissolveVisitor(FeatureProcessor processor) {

                this.featureProcessor = processor;

                dissolvedGeometries = new FBitSet();

        }

        public int getNumProcessedGeometries(){

                return dissolvedGeometries.cardinality();

        }

        /*

         * Algorithm to compute dissolve is strongly based in depth first 

         * algorithm to traverse graphs.

         * 

         * It puts features to dissolve in a stack. 

         * While stack is not empty, get Features and looks for adjacent to it. 

         * For each adjacent feature, verify its dissolve field value, 

         * and if it is similar to feature to dissolve

         * with, obtain a new feature by unioning their geometries.

         * For each adjacent feature, put it in the Stack

         */

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

                if (!dissolvedGeometries.get(index)) {

                        // if we havent dissolved this feature

                        Stack toDissol = new Stack();// stack for adjacent features

                        DissolvedFeature feature;

                        try {

                                feature = createFeature(g, index);

                                Geometry jtsGeometry = g.toJTSGeometry();

                                feature.setJtsGeometry(jtsGeometry);

                                toDissol.push(feature);

                                List geometries = dissolve(toDissol);

                                Geometry dissolvedGeom = union(geometries);

                                DissolvedFeature newFeature = 

                                        createFeature(null, -1);

                                newFeature.setJtsGeometry(dissolvedGeom);

                                this.featureProcessor.processFeature(newFeature);

                        } catch (DriverException e) {

                                throw new VisitException(

                                                "Error al procesar las geometrias a fusionar durante dissolve");

                        } catch (com.iver.cit.gvsig.fmap.DriverException e) {

                                throw new VisitException(

                                                "Error al procesar las geometrias a fusionar durante dissolve");

                        }

                }// if

        }

        protected Geometry union(List geometries){

                Geometry[] geom = new Geometry[geometries.size()];

                geometries.toArray(geom);

                GeometryFactory fact = geom[0].getFactory();

            Geometry geomColl = fact.createGeometryCollection(geom);

            Geometry union = geomColl.buffer(0.0);

            return union;

        }

        /**

         * Inner class to manage dissolve geoprocess. It mantains feature info

         * interesting for dissolve (int index, JTS Geometry, etc)

         * 

         * @author azabala

         * 

         */

        class DissolvedFeature extends DefaultFeature {

                int index;

                Geometry jtsGeometry;

                public DissolvedFeature(IGeometry geom, Value[] att, int index) {

                        super(geom, att);

                        this.index = index;

                }

                public int getIndex() {

                        return index;

                }

                public Geometry getJtsGeometry() {

                        return jtsGeometry;

                }

                public void setJtsGeometry(Geometry jtsGeometry) {

                        this.jtsGeometry = jtsGeometry;

                }

                public IGeometry getGeometry() {

                        IGeometry solution = super.getGeometry();

                        if (solution == null && jtsGeometry != null) {

                                solution = FConverter.jts_to_igeometry(jtsGeometry);

                        }

                        return solution;

                }

        }

        /**

         * Creates a new IFeature with util info for dissolve geoprocess (it ignores

         * non numerical values, etc)

         * 

         * @param g

         * @param index

         * @return

         * @throws DriverException

         */

        private DissolvedFeature createFeature(IGeometry g, int index)

                        throws DriverException {

                DissolvedFeature solution = new DissolvedFeature(g, null, index);

                return solution;

        }

        /**

         * For each individual geometry processed in DissolveVisitor's visit

         * method, this Visitor visits its adjacent polygons geometries to check 

         * dissolve conditions.

         * 

         * @author azabala

         * 

         */

        class IndividualGeometryDissolveVisitor implements FeatureVisitor {

                /**

                 * Marks index of features that have been dissolved yet

                 */

                FBitSet dissolvedFeatures;

                /**

                 * It saves all features for we are looking for adjacent geometries.

                 * Dissolving is similar to network tracking algorithms: one feature is

                 * adjacent to two, two is adjacent to four, etc We will save features

                 * to process in this stack (Depth first aproximation)

                 */

                Stack featuresToDissolve;

                /**

                 * Feature for which we are looking for features to dissolve

                 */

                DissolvedFeature feature;

                /**

                 * Recordset to recover attribute values

                 */

                SelectableDataSource recordset;

                IndividualGeometryDissolveVisitor(DissolvedFeature feature,

                                FBitSet dissolvedFeatures, Stack featuresToDissolve) {

                        this.dissolvedFeatures = dissolvedFeatures;

                        this.feature = feature;

                        this.featuresToDissolve = featuresToDissolve;

                }

                public String getProcessDescription() {

                        return "Dissolving a polygon with its adjacents";

                }

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

                        // Its the feature whose adjacents we are looking for?

                        if (index == feature.getIndex())

                                return;

                        // have we dissolved this feature yet?

                        if (dissolvedFeatures.get(index))

                                return;

                        try {

                                Geometry jtsGeo = g.toJTSGeometry();

                                DissolvedFeature adjacentFeature = createFeature(g, index);

                                adjacentFeature.setJtsGeometry(jtsGeo);

                                if (jtsGeo.intersects(feature.getJtsGeometry())) {// They are adjacent

                                        //TODO PARA HACER GENERICO EL ALGORITMO, Y QUE VALGA

                                        //TANTO PARA DISSOLVER BUFFERS COMO PARA UN DISSOLVE 

                                        //ALFANUMERICO, AQUI USARIAMOS UN STRATEGY DISTINTO

                                                dissolvedFeatures.set(index);

                                                featuresToDissolve.push(adjacentFeature);

                                                //geometriesToDissolve.add(jtsGeo);

                                                //List toDissolve = dissolve(featuresToDissolve);

                                                //geometriesToDissolve.addAll(toDissolve);

                                }// if touches

                        } catch (DriverException e) {

                                throw new VisitException(

                                                "Error al cargar los pol?gonos adyacentes durante un dissolve");

                        } 

                }// visit

                public void stop(FLayer layer) {

                }

                // FIXME Create an abstract FeatureVisitor

                public boolean start(FLayer layer) {

                        try {

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

                        } catch (com.iver.cit.gvsig.fmap.DriverException e) {

                                return false;

                        }

                        return true;

                }

                public void setProcessedFeature(DissolvedFeature feature2) {

                        this.feature = feature2;

                }

        }// IndividualDissolve

        private List dissolve(Stack toDissol)

                        throws com.iver.cit.gvsig.fmap.DriverException, VisitException {

                List solution = new ArrayList();

                while (toDissol.size() != 0) {

                        DissolvedFeature feature = (DissolvedFeature) toDissol.pop();

                        // flags this idx (to not to process in future)

                        dissolvedGeometries.set(feature.getIndex());

                        if (visitor == null) {

                                visitor = new IndividualGeometryDissolveVisitor(feature,

                                                dissolvedGeometries, toDissol);

                        } else {

                                visitor.setProcessedFeature(feature);

                        }

                        solution.add(feature.getJtsGeometry());

                        Rectangle2D bounds = feature.getGeometry().getBounds2D();

                        double xmin = bounds.getMinX();

                        double ymin = bounds.getMinY();

                        double xmax = bounds.getMaxX();

                        double ymax = bounds.getMaxY();

                        double magnify = 15d;

                        Rectangle2D query = new Rectangle2D.Double(xmin - magnify, ymin

                                        - magnify, (xmax - xmin) + magnify, (ymax - ymin) + magnify);

                        strategy.process(visitor, query);

                }// while

                return solution;

        }

        public void stop(FLayer layer) {

                this.featureProcessor.finish();

        }

        public boolean start(FLayer layer) {

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

                        try {

                                dissolvedLayer = (FLyrVect) layer;

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

                                featureProcessor.start();

                        } catch (com.iver.cit.gvsig.fmap.DriverException e) {

                                return false;

                        } catch (EditionException e) {

                                return false;

                        }

                        return true;

                }

                return false;

        }

        public void setStrategy(Strategy strategy) {

                this.strategy = strategy;

        }

        public String getProcessDescription() {

                return "Dissolving polygons of a layer";

        }

}