/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.axiom.om.impl.traverse;
import java.util.Iterator;
import java.util.NoSuchElementException;
import org.apache.axiom.om.OMNode;
/**
* Abstract iterator that returns matching nodes from another iterator.
*/
public abstract class OMFilterIterator implements Iterator {
private final Iterator parent;
private OMNode nextNode;
private boolean noMoreNodes;
public OMFilterIterator(Iterator parent) {
this.parent = parent;
}
/**
* Determine whether the given node matches the filter criteria.
*
* @param node the node to test
* @return true if the node matches, i.e. if it should be returned
* by a call to {@link #next()}
*/
protected abstract boolean matches(OMNode node);
public boolean hasNext() {
if (noMoreNodes) {
return false;
} else if (nextNode != null) {
return true;
} else {
while (parent.hasNext()) {
OMNode node = (OMNode)parent.next();
if (matches(node)) {
nextNode = node;
return true;
}
}
noMoreNodes = true;
return false;
}
}
public Object next() {
if (hasNext()) {
OMNode result = nextNode;
nextNode = null;
return result;
} else {
throw new NoSuchElementException();
}
}
public void remove() {
parent.remove();
}
}