/*
* 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.commons.jxpath.ri.model.beans;
import java.util.ArrayList;
import java.util.List;
import org.apache.commons.jxpath.JXPathException;
import org.apache.commons.jxpath.ri.model.NodeIterator;
import org.apache.commons.jxpath.ri.model.NodePointer;
/**
* Combines node iterators of all elements of a collection into one
* aggregate node iterator.
*
* @author Dmitri Plotnikov
* @version $Revision: 652845 $ $Date: 2008-05-02 12:46:46 -0500 (Fri, 02 May 2008) $
*/
public abstract class CollectionNodeIterator implements NodeIterator {
private CollectionPointer pointer;
private boolean reverse;
private NodePointer startWith;
private int position;
private List collection;
/**
* Create a new CollectionNodeIterator.
* @param pointer collection pointer
* @param reverse iteration order
* @param startWith starting pointer
*/
protected CollectionNodeIterator(
CollectionPointer pointer,
boolean reverse,
NodePointer startWith) {
this.pointer = pointer;
this.reverse = reverse;
this.startWith = startWith;
}
/**
* Implemented by subclasses to produce child/attribute node iterators.
* @param elementPointer owning pointer
* @return NodeIterator
*/
protected abstract NodeIterator
getElementNodeIterator(NodePointer elementPointer);
public int getPosition() {
return position;
}
public boolean setPosition(int position) {
if (collection == null) {
prepare();
}
if (position < 1 || position > collection.size()) {
return false;
}
this.position = position;
return true;
}
public NodePointer getNodePointer() {
if (position == 0) {
return null;
}
return (NodePointer) collection.get(position - 1);
}
/**
* Prepare...
*/
private void prepare() {
collection = new ArrayList();
NodePointer ptr = (NodePointer) pointer.clone();
int length = ptr.getLength();
for (int i = 0; i < length; i++) {
ptr.setIndex(i);
NodePointer elementPointer = ptr.getValuePointer();
NodeIterator iter = getElementNodeIterator(elementPointer);
for (int j = 1; iter.setPosition(j); j++) {
NodePointer childPointer = iter.getNodePointer();
if (reverse) {
collection.add(0, childPointer);
}
else {
collection.add(childPointer);
}
}
}
if (startWith != null) {
int index = collection.indexOf(startWith);
if (index == -1) {
throw new JXPathException(
"Invalid starting pointer for iterator: " + startWith);
}
while (collection.size() > index) {
if (!reverse) {
collection.remove(collection.size() - 1);
}
else {
collection.remove(0);
}
}
}
}
}
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