| gvSIG desktop 1

package org.gvsig.data.vectorial.order;

import java.util.Comparator;

import java.util.Iterator;

import org.gvsig.data.exception.EvaluationExpressionException;

import org.gvsig.data.exception.ReadException;

import org.gvsig.data.vectorial.IFeature;

import org.gvsig.data.vectorial.IFeatureAttributeDescriptor;

import org.gvsig.data.vectorial.IFeatureID;

import org.gvsig.data.vectorial.IFeatureType;

import org.gvsig.data.vectorial.filter.FeatureFilterParser;

public class FeatureComparator implements Comparator {

        protected String expresionString;

        protected IFeatureType featureType;

        protected ComparatorToken[] tokens;

        public FeatureComparator(IFeatureType featureType,String expresion){

                this.featureType=featureType;

                this.expresionString=expresion;

                this.initExpressionList();

        }

        protected void initExpressionList(){

                String[] stokens = this.expresionString.split(",");

                tokens = new ComparatorToken[stokens.length];

                String stoken;

                int i;

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

                        stoken = stokens[i].trim();

                        tokens[i] = new ComparatorToken(stoken,this.featureType);

                }

        }

        private IFeature toFeature(Object arg) throws ReadException{

                if (arg instanceof IFeatureID){

                        return ((IFeatureID)arg).getFeature(featureType);

                } else {

                        return (IFeature)arg;

                }

        }

        public int compare(Object arg0, Object arg1) {

                IFeature feature0, feature1;

                try {

                        feature0 = toFeature(arg0);

                        feature1 = toFeature(arg1);

                } catch (ReadException e1) {

                        throw new RuntimeException(e1);

                        //FIXME: OJO!!!! Revisar la excepcion que lanzamos aqui!!!!

                        // Tendriamos que lanzar un ReadException, pero

                        // no podemos por implementar el interface 'Comparator'.

                }

                int i,result;

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

                        try {

                                result=tokens[i].compareFeatures(feature0, feature1);

                        } catch (ReadException e) {

                                throw new RuntimeException(e);

                                //FIXME: OJO!!!! Revisar la excepcion que lanzamos aqui!!!!

                                // Tendriamos que lanzar un ReadException, pero

                                // no podemos por implementar el interface 'Comparator'.

                        }

                        if (result != 0){

                                return result;

                        }

                }

                // Son iguales sus valores, pero si devolvemos

                // un 0 java puede considera que 'ES EL MISMO OBJETO'

                // y decidir NO A?ADIR a una lista una de las dos

                // features.

                // Por eso comparamo primero sus 'FeatureID' y

                // si son iguales devolvemos un 0 (es la misma feature)

                // sino devuelve -1.

                if (feature0.getID().equals(feature1.getID())){

                        return 0;

                }

                return -1;

        }

        private class ComparatorToken{

                private String textToken;

                private String textParser;

                private boolean ascendent=true;

                private FeatureFilterParser parser;

                private IFeatureType featureType;

                private boolean isSimple=false;

                public ComparatorToken(String textToken,IFeatureType featureType){

                        this.textToken= textToken;

                        this.featureType= featureType;

                        if (this.textToken.toLowerCase().endsWith(" desc")){

                                this.textParser = this.textToken.substring(0,this.textToken.length()-5);

                                this.ascendent=false;

                        } else if (this.textToken.toLowerCase().endsWith(" asc")) {

                                this.textParser = this.textToken.substring(0,this.textToken.length()-4);

                        } else{

                                this.textParser = this.textToken;

                        }

                        Iterator iter = this.featureType.iterator();

                        IFeatureAttributeDescriptor attribute;

                        while (iter.hasNext()){

                                attribute = (IFeatureAttributeDescriptor)iter.next();

                                if (attribute.getName().equalsIgnoreCase(this.textParser)){

                                        this.isSimple=true;

                                        this.textParser=attribute.getName();

                                        break;

                                }

                        }

                        if (!this.isSimple){

                                this.parser = new FeatureFilterParser(this.textParser,this.featureType);

                        }

                }

                public int compareFeatures(IFeature feature0,IFeature feature1) throws ReadException{

                        Comparable value0,value1;

                        if (this.isSimple){

                                value0 = (Comparable)feature0.get(this.textParser);

                                value1 = (Comparable)feature1.get(this.textParser);

                        }else{

                                value0 = parser.getValue(feature0);

                                value1 = parser.getValue(feature1);

                        }

                        if (ascendent){

                                if (value0 == null){

                                        return 1;

                                } else if (value1 == null){

                                        return -1;

                                }

                                return value0.compareTo(value1);

                        }else{

                                if (value1 == null){

                                        return 1;

                                } else if (value0 == null){

                                        return -1;

                                }

                                return value1.compareTo(value0);

                        }

                }

        }

}