/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2005-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library 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
* Lesser General Public License for more details.
*/
package org.geotools.feature.collection;
import org.geotools.data.DataUtilities;
import org.geotools.data.Query;
import org.geotools.data.simple.SimpleFeatureCollection;
import org.geotools.data.simple.SimpleFeatureIterator;
import org.geotools.data.simple.SimpleFeatureSource;
import org.geotools.data.store.EmptyFeatureCollection;
import org.geotools.factory.CommonFactoryFinder;
import org.geotools.geometry.jts.ReferencedEnvelope;
import org.opengis.filter.Filter;
import org.opengis.filter.FilterFactory;
import org.opengis.filter.sort.SortBy;
/**
* Reasonable default implementation for subCollection making
* use of parent {@link SimpleFeatureCollection#features()}
* and provided Filter.
* <p>
* This is only a reasonable implementation and is not optimal. It is recommended
* that implementors construct a new {@link Query} and use {@link SimpleFeatureSource#getFeatures(Query)}.
*
* @author Jody Garnett, Refractions Research, Inc.
* @source $URL$
*/
public class SubFeatureCollection extends BaseSimpleFeatureCollection {
/** Filter */
protected Filter filter;
/** Original Collection */
protected SimpleFeatureCollection collection;
protected FilterFactory ff = CommonFactoryFinder.getFilterFactory();
public SubFeatureCollection(SimpleFeatureCollection collection) {
this( collection, Filter.INCLUDE );
}
/**
* @param collection Collection or AbstractFeatureCollection
* @param subfilter
*/
public SubFeatureCollection(SimpleFeatureCollection collection, Filter subfilter) {
super( collection.getSchema() );
if (subfilter == null){
subfilter = Filter.INCLUDE;
}
if (subfilter.equals(Filter.EXCLUDE)) {
throw new IllegalArgumentException("A subcollection with Filter.EXCLUDE would be empty");
}
if (collection instanceof SubFeatureCollection) {
SubFeatureCollection filtered = (SubFeatureCollection) collection;
if (subfilter.equals(Filter.INCLUDE)) {
this.collection = filtered.collection;
this.filter = filtered.filter();
} else {
this.collection = filtered.collection;
this.filter = ff.and(filtered.filter(), subfilter);
}
} else {
this.collection = collection;
this.filter = subfilter;
}
}
public SimpleFeatureIterator features() {
return new FilteringSimpleFeatureIterator( collection.features(), filter());
}
public int size() {
int count = 0;
SimpleFeatureIterator i = features();
try {
while (i.hasNext()) {
i.next();
count++;
}
} finally {
i.close();
}
return count;
}
/**
* Generate filter to use for content, makes use of {@link #createFilter()}
* if needed.
*
* @return Filter to use for content
*/
protected Filter filter() {
if (filter == null) {
filter = createFilter();
}
return filter;
}
/** Override to implement subsetting */
protected Filter createFilter(){
return Filter.INCLUDE;
}
public SimpleFeatureCollection subCollection(Filter filter) {
if (filter.equals(Filter.INCLUDE)) {
return this;
}
if (filter.equals(Filter.EXCLUDE)) {
return new EmptyFeatureCollection( schema );
}
return new SubFeatureCollection(this, filter);
}
public SimpleFeatureCollection sort(SortBy order) {
return new SubFeatureList( collection, filter, order );
}
public String getID() {
return collection.getID();
}
/**
* Calculates the bounds of the features without caching.
*/
@Override
public ReferencedEnvelope getBounds() {
return DataUtilities.bounds(this);
}
}