| gvSIG desktop 1

/*

 * Created on 24-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: DissolveVisitor.java 4447 2006-03-15 18:35:56Z azabala $

 * $Log$

 * Revision 1.3  2006-03-15 18:33:24  azabala

 * *** empty log message ***

 *

 * Revision 1.2  2006/03/07 21:01:33  azabala

 * *** empty log message ***

 *

 * Revision 1.1  2006/03/06 19:48:39  azabala

 * *** empty log message ***

 *

 * Revision 1.2  2006/03/05 19:58:30  azabala

 * *** empty log message ***

 *

 * Revision 1.1  2006/02/26 20:54:04  azabala

 * *** empty log message ***

 *

 *

 */

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

import java.awt.geom.Rectangle2D;

import java.util.ArrayList;

import java.util.Iterator;

import java.util.List;

import java.util.Map;

import java.util.Stack;

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

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

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.iver.gvsig.geoprocessing.model.SummarizationFunction;

import com.vividsolutions.jts.geom.Geometry;

/**

 * This FeatureVisitor processes each geometry of a polygon layer, looks for

 * adjacent polygons and verify values of a dissolve field. If these values are

 * coincident, it creates a new polygon by unioning original polygons. Also

 * applies a sumarization function to numeric fields of original features.

 * 

 * @author azabala

 * 

 */

public class DissolveVisitor 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;

        /**

         * Field which adjacent features must have the same value to dissolve them

         */

        String dissolveField;

        /**

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

         * them in subsecuent steps)

         * 

         */

        FBitSet dissolvedGeometries;

        /**

         * Relates a numerical field name with its sumarization functions

         */

        Map numericField_sumarizeFunction;

        /**

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

         * them in memory, etc)

         */

        FeatureProcessor featureProcessor;

        Strategy strategy;

        /**

         * Constructor

         * 

         * @param layerToDissolve

         */

        public DissolveVisitor(String dissolveField, FeatureProcessor processor) {

                this.dissolveField = dissolveField;

                this.featureProcessor = processor;

                dissolvedGeometries = new FBitSet();

        }

        public int getNumProcessedGeometries(){

                return dissolvedGeometries.cardinality();

        }

        public void setDissolvedAttributesInfo(Map numericField_sumFunction) {

                this.numericField_sumarizeFunction = numericField_sumFunction;

        }

        /*

         * 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 and by applying

         * sumarization functions to its numeric attributes. 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);

                                toDissol.push(feature);

                                DissolvedFeature dissolved = dissolve(toDissol);

                                this.featureProcessor.processFeature(dissolved);

                                resetFunctions();

                        } 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

        }

        /**

         * FIXME Redise?ar esto, pues el codigo es similar al de Spatial Join

         *

         */

        void resetFunctions() {

                Iterator fieldsIt = numericField_sumarizeFunction.keySet().iterator();

                while (fieldsIt.hasNext()) {

                        String field = (String) fieldsIt.next();

                        SummarizationFunction[] functions = (SummarizationFunction[]) numericField_sumarizeFunction

                                        .get(field);

                        for (int i = 0; i < functions.length; i++) {

                                functions[i].reset();

                        }// for

                }// while

        }

        /**

         * 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 = null;

                int numNumericFields = numericField_sumarizeFunction.keySet().size();

                // attributes will be dissolve field and sumarized function for

                // numerical

                // values

                Value[] values = new Value[numNumericFields + 1];

                Iterator fieldIt = numericField_sumarizeFunction.keySet().iterator();

                int valueIndex = 0;

                while (fieldIt.hasNext()) {

                        String fieldName = (String) fieldIt.next();

                        int fieldIndex = recordset.getFieldIndexByName(fieldName);

                        values[valueIndex] = recordset.getFieldValue(index, fieldIndex);

                        valueIndex++;

                }

                int dissolveField = recordset.getFieldIndexByName(this.dissolveField);

                values[numNumericFields] = recordset

                                .getFieldValue(index, dissolveField);

                solution = new DissolvedFeature(g, values, 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

                 */

                Stack featuresToDissolve;

                /**

                 * Field use to dissolve adjacent geometries with the same value for it

                 */

                String dissolveField;

                /**

                 * Maps for each numerical field its sumarization functions

                 */

                Map fields_sumarizeFunc;

                /**

                 * Feature for which we are looking for features to dissolve

                 */

                DissolvedFeature feature;

                /**

                 * jts geometry of feature

                 */

                private Geometry featureJtsGeo;

                /**

                 * Numeric values result of a sumarization operation

                 */

                private List sumarizedValues;

                /**

                 * Recordset to recover attribute values

                 */

                SelectableDataSource recordset;

                IndividualGeometryDissolveVisitor(DissolvedFeature feature,

                                FBitSet dissolvedFeatures, Stack featuresToDissolve, Map fields_sumarize) {

                        this.dissolvedFeatures = dissolvedFeatures;

                        this.feature = feature;

                        this.featuresToDissolve = featuresToDissolve;

                        this.featureJtsGeo = feature.getGeometry().toJTSGeometry();

                        this.sumarizedValues = new ArrayList();

                        this.fields_sumarizeFunc = fields_sumarize;

                }

                public String getProcessDescription() {

                        return "Dissolving a polygon with its adjacents";

                }

                /**

                 * Applies to sumarization functions feature values.

                 * @throws DriverException 

                 * 

                 * FIXME Redise?ar, pues el codigo es similar al de Spatial Join

                 */

                private void applySumarizeFunction(int recordIndex) 

                                                                                throws DriverException{

                        Iterator fieldsIt = fields_sumarizeFunc.keySet()

                                        .iterator();

                        while (fieldsIt.hasNext()) {

                                String field = (String) fieldsIt.next();

                                int fieldIndex = recordset.getFieldIndexByName(field);

                                Value valToSumarize = recordset.getFieldValue(

                                                recordIndex, fieldIndex);

                                SummarizationFunction[] functions = (SummarizationFunction[]) fields_sumarizeFunc

                                                .get(field);

                                for (int i = 0; i < functions.length; i++) {

                                        functions[i]

                                                        .process((NumericValue) valToSumarize);

                                        sumarizedValues.add(functions[i]

                                                        .getSumarizeValue());

                                }// for

                        }// while

                }

                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 {

                                DissolvedFeature adjacentFeature = createFeature(g, index);

                                IGeometry geometry = adjacentFeature.getGeometry();

                                Geometry jtsGeo = geometry.toJTSGeometry();

                                adjacentFeature.setJtsGeometry(jtsGeo);

                                if (jtsGeo.touches(featureJtsGeo)) {// They are adjacent

                                        // dissolveField is the last

                                        int fieldIndex = numericField_sumarizeFunction.keySet()

                                                        .size();

                                        Value adjacentVal = adjacentFeature

                                                        .getAttribute(fieldIndex);

                                        Value val = feature.getAttribute(fieldIndex);

                                        if (adjacentVal.doEquals(val)) {

                                                dissolvedFeatures.set(index);

                                                // we actualize geometry by unioning

                                                featuresToDissolve.push(adjacentFeature);

                                                DissolvedFeature fet = dissolve(featuresToDissolve);

                                                // group by geometry

                                                featureJtsGeo = featureJtsGeo.union(fet

                                                                .getJtsGeometry());

                                                // group by attributes

                                                applySumarizeFunction(index);

                                        }// if val equals

                                }// if touches

                                /*

                                 * else{ //must we cache IGeometries that dont have the same

                                 * values //for speed up next processes? }

                                 */

                        } catch (DriverException e) {

                                throw new VisitException(

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

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

                                throw new VisitException(

                                                "Error al procesar 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();

                                this.applySumarizeFunction(feature.getIndex());

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

                                return false;

                        } catch (DriverException e) {

                                return false;

                        }

                        return true;

                }

                public void setFields_sumarizeFunc(Map fields_sumarizeFunc) {

                        this.fields_sumarizeFunc = fields_sumarizeFunc;

                }

                public Map getFields_sumarizeFunc() {

                        return fields_sumarizeFunc;

                }

                public Geometry getFeatureJtsGeo() {

                        return featureJtsGeo;

                }

                public Value[] getSumarizedValues() {

                        Value[] solution = new Value[sumarizedValues.size()];

                        sumarizedValues.toArray(solution);

                        return solution;

                }

                public Value[] getSumarizedValues2() {

                        Value[] solution = null;

                        ArrayList values = new ArrayList();

                        Iterator fieldsIt = fields_sumarizeFunc.keySet().iterator();

                        while (fieldsIt.hasNext()) {

                                String field = (String) fieldsIt.next();

                                SummarizationFunction[] functions = (SummarizationFunction[]) fields_sumarizeFunc

                                                .get(field);

                                for (int i = 0; i < functions.length; i++) {

                                        values.add(functions[i].getSumarizeValue());

                                }// for

                        }// while

                        solution = new Value[values.size()];

                        values.toArray(solution);

                        return solution;

                }

                public void setDissolveField(String dissolveField) {

                        this.dissolveField = dissolveField;

                }

                public void setProcessedFeature(DissolvedFeature feature2) {

                        this.feature = feature2;

                }

        }// IndividualDissolve

        private DissolvedFeature dissolve(Stack toDissol)

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

                DissolvedFeature feature = null;

                Geometry jtsGeometry = null;

                IndividualGeometryDissolveVisitor visitor = null;

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

                        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, numericField_sumarizeFunction);

                                visitor.setDissolveField(this.dissolveField);

                        } else {

                                visitor.setProcessedFeature(feature);

                        }

                        // FIXME Si hacemos una busqueda de adyacencia a partir de un

                        // rectangulo

                        // nunca obtendremos resultados, porque no intersectan.

                        // De momento agrandamos el rectangulo, pero lo que hay que hacer es

                        // implementar

                        // process(FeatureVisitor, IGeometry) (SelectByShapeVisitor)

                        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);

                        Geometry jtsGeo = visitor.getFeatureJtsGeo();

                        if (jtsGeometry == null) {

                                jtsGeometry = jtsGeo;

                        } else {

                                jtsGeometry = jtsGeometry.union(jtsGeo);

                        }

                }// while

                Value[] values = visitor.getSumarizedValues2();

                feature = new DissolvedFeature(null, values, -1);

                feature.setJtsGeometry(jtsGeometry);

                return feature;

        }

        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";

        }

}