/*
* The Unified Mapping Platform (JUMP) is an extensible, interactive GUI
* for visualizing and manipulating spatial features with geometry and attributes.
*
* Copyright (C) 2003 Vivid Solutions
*
* 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:
*
* Vivid Solutions
* Suite #1A
* 2328 Government Street
* Victoria BC V8T 5G5
* Canada
*
* (250)385-6040
* www.vividsolutions.com
*/
package com.vividsolutions.jump.feature;
import java.util.*;
import com.vividsolutions.jts.geom.Envelope;
import com.vividsolutions.jts.geom.Geometry;
import com.vividsolutions.jts.index.SpatialIndex;
import com.vividsolutions.jts.index.strtree.STRtree;
/**
* An IndexedFeatureCollection creates a new collection which is backed by a
* FeatureCollection, but which is indexed for query purposes.
*/
public class IndexedFeatureCollection extends FeatureCollectionWrapper {
private SpatialIndex spatialIndex;
public IndexedFeatureCollection(FeatureCollection fc) {
//Based on tests on Victoria ICI data, 10 is an optimum node-capacity for
//fast queries. [Jon Aquino]
this(fc, new STRtree(10));
}
public IndexedFeatureCollection(FeatureCollection fc,
SpatialIndex spatialIndex) {
super(fc);
this.spatialIndex = spatialIndex;
createIndex();
}
public void add(Feature feature) {
throw new UnsupportedOperationException("Index cannot be modified");
}
public void remove(Feature feature) {
throw new UnsupportedOperationException("Index cannot be modified");
}
public List query(Envelope env) {
//System.out.println("FC size = " + base.size());
//System.out.println("Quadtree size = " + quadtreeIndex.size());
// index query returns list of *potential* overlaps (e.g. it is a primary filter)
List candidate = spatialIndex.query(env);
// filter out only Features where envelope actually intersects
List result = new ArrayList();
for (Iterator i = candidate.iterator(); i.hasNext();) {
Feature f = (Feature) i.next();
Geometry g = f.getGeometry();
if (env.intersects(g.getEnvelopeInternal())) {
result.add(f);
}
}
return result;
}
private void createIndex() {
int count = 0; // debugging
for (Iterator i = iterator(); i.hasNext();) {
Feature f = (Feature) i.next();
spatialIndex.insert(f.getGeometry().getEnvelopeInternal(), f);
count++;
}
}
public void addAll(Collection features) {
throw new UnsupportedOperationException("Index cannot be modified");
}
public Collection remove(Envelope env) {
throw new UnsupportedOperationException("Index cannot be modified");
}
public void removeAll(Collection features) {
throw new UnsupportedOperationException("Index cannot be modified");
}
}