/*
* Copyright 1999-2004 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.jxpath.ri.axes;
import java.util.HashSet;
import org.apache.commons.jxpath.BasicNodeSet;
import org.apache.commons.jxpath.ri.EvalContext;
import org.apache.commons.jxpath.ri.model.NodePointer;
/**
* EvalContext that represents a union between other contexts - result
* of a union operation like (a | b)
*
* @author Dmitri Plotnikov
* @version $Revision: 1.12 $ $Date: 2004/02/29 14:17:38 $
*/
public class UnionContext extends NodeSetContext {
private boolean startedSet = false;
private EvalContext contexts[];
private boolean prepared = false;
public UnionContext(EvalContext parentContext, EvalContext contexts[]) {
super(parentContext, new BasicNodeSet());
this.contexts = contexts;
}
public int getDocumentOrder() {
if (contexts.length > 1) {
return 1;
}
return super.getDocumentOrder();
}
public boolean setPosition(int position) {
if (!prepared) {
prepared = true;
BasicNodeSet nodeSet = (BasicNodeSet) getNodeSet();
HashSet set = new HashSet();
for (int i = 0; i < contexts.length; i++) {
EvalContext ctx = (EvalContext) contexts[i];
while (ctx.nextSet()) {
while (ctx.nextNode()) {
NodePointer ptr = ctx.getCurrentNodePointer();
if (!set.contains(ptr)) {
nodeSet.add(ptr);
set.add(ptr);
}
}
}
}
}
return super.setPosition(position);
}
}