/*
* 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.visitor;
import org.geotools.feature.FeatureCollection;
import org.geotools.feature.visitor.SumVisitor.SumResult;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.simple.SimpleFeatureType;
/**
* Determines the number of features in the collection
*
* @author Cory Horner, Refractions
*
* @since 2.2.M2
* @source $URL$
*/
public class CountVisitor implements FeatureCalc {
int count = 0;
public void init(FeatureCollection<SimpleFeatureType, SimpleFeature> collection) {
//do nothing
}
public void visit(SimpleFeature feature) {
visit((org.opengis.feature.Feature)feature);
}
public void visit(org.opengis.feature.Feature feature) {
count++;
}
public int getCount() {
return count;
}
public void setValue(int count) {
this.count = count;
}
public void reset() {
this.count = 0;
}
public CalcResult getResult() {
return new CountResult(count);
}
public static class CountResult extends AbstractCalcResult {
private int count;
public CountResult(int newcount) {
count = newcount;
}
public Object getValue() {
return new Integer(count);
}
public boolean isCompatible(CalcResult targetResults) {
if (targetResults instanceof CountResult) return true;
if (targetResults instanceof SumResult) return true;
return false;
}
public CalcResult merge(CalcResult resultsToAdd) {
if (!isCompatible(resultsToAdd)) {
throw new IllegalArgumentException(
"Parameter is not a compatible type");
}
if (resultsToAdd instanceof CountResult) {
//add the two counts
int toAdd = resultsToAdd.toInt();
return new CountResult(count + toAdd);
} else if (resultsToAdd instanceof SumResult) {
// we don't want to implement this twice, so we'll call the
// SumResult version of this function
return resultsToAdd.merge(this);
} else {
throw new IllegalArgumentException(
"The CalcResults claim to be compatible, but the appropriate merge method has not been implemented.");
}
}
}
}