Application: gvSIG desktop

package org.gvsig.fmap.dal.feature.impl.featureset;

import java.util.Comparator;

import java.util.Iterator;

import org.gvsig.fmap.dal.exception.DataEvaluatorRuntimeException;

import org.gvsig.fmap.dal.feature.FeatureQueryOrder;

import org.gvsig.fmap.dal.feature.FeatureType;

import org.gvsig.fmap.dal.feature.FeatureQueryOrder.FeatureQueryOrderMember;

import org.gvsig.fmap.dal.feature.impl.DefaultFeature;

import org.gvsig.fmap.dal.feature.impl.DefaultFeatureStore;

import org.gvsig.fmap.dal.feature.spi.FeatureData;

import org.gvsig.tools.evaluator.Evaluator;

import org.gvsig.tools.evaluator.EvaluatorException;

/*

*

* Compara dos Feature o FeatureData.

*/

public class FeatureDataComparator implements Comparator {

        private FeatureQueryOrder order;

        private DefaultFeature f1;

        private DefaultFeature f2;

        private DefaultFeatureStore store;

        private OrderElement[] elements = null;

        private class OrderElement {

                FeatureQueryOrderMember order = null;

                int fieldIndex = -1;

        }

        public FeatureDataComparator(DefaultFeatureStore store, FeatureQueryOrder order) {

                this.order = order;

                this.store = store;

                this.f1 = new DefaultFeature(this.store);

                this.f2 = new DefaultFeature(this.store);

        }

        private void initElements(FeatureType type) {

                elements = new OrderElement[this.order.size()];

                OrderElement cur;

                Iterator iter = order.iterator();

                FeatureQueryOrderMember orderItem;

                int i = 0;

                while (iter.hasNext()) {

                        cur = new OrderElement();

                        cur.order = (FeatureQueryOrderMember) iter.next();

                        if (!cur.order.hasEvaluator()) {

                                cur.fieldIndex = type.getIndex(cur.order.getAttributeName());

                        }

                        elements[i] = cur;

                        i++;

                }

        }

        public int compare(Object arg0, Object arg1) {

                FeatureQueryOrderMember order;

                Comparable v1;

                Comparable v2;

                Object o1;

                Object o2;

                int v;

                int fieldIndex;

                f1.setData((FeatureData) arg0);

                f2.setData((FeatureData) arg1);

                if (elements == null){

                        initElements(f1.getType());

                }

                OrderElement element;

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

                        element = elements[i];

                        if (element.order.hasEvaluator()) {

                                Evaluator evaluator = element.order.getEvaluator();

                                try {

                                        o1 = evaluator.evaluate(f1);

                                        o2 = evaluator.evaluate(f2);

                                } catch (EvaluatorException e) {

                                        throw new DataEvaluatorRuntimeException(e);

                                }

                        } else {

                                o1 = f1.get(element.fieldIndex);

                                o2 = f2.get(element.fieldIndex);

                        }

                        if (o1 == null) {

                                if (o2 == null) {

                                        return 0;

                                } else {

                                        v = 1;

                                }

                        } else {

                                if (o1 instanceof Comparable && o2 instanceof Comparable) {

                                        v1 = (Comparable) o1;

                                        v2 = (Comparable) o2;

                                        v = v1.compareTo(v2);

                                } else {

                                        v = -1;

                                }

                        }

                        if (v != 0) {

                                if (element.order.getAscending()) {

                                        return v;

                                } else {

                                        return -v;

                                }

                        }

                }

                return 0;

        }

}