/*--
$Id: DescendantIterator.java,v 1.5 2004/02/27 11:32:57 jhunter Exp $
Copyright (C) 2000-2004 Jason Hunter & Brett McLaughlin.
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions, and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions, and the disclaimer that follows
these conditions in the documentation and/or other materials
provided with the distribution.
3. The name "JDOM" must not be used to endorse or promote products
derived from this software without prior written permission. For
written permission, please contact <request_AT_jdom_DOT_org>.
4. Products derived from this software may not be called "JDOM", nor
may "JDOM" appear in their name, without prior written permission
from the JDOM Project Management <request_AT_jdom_DOT_org>.
In addition, we request (but do not require) that you include in the
end-user documentation provided with the redistribution and/or in the
software itself an acknowledgement equivalent to the following:
"This product includes software developed by the
JDOM Project (http://www.jdom.org/)."
Alternatively, the acknowledgment may be graphical using the logos
available at http://www.jdom.org/images/logos.
THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE JDOM AUTHORS OR THE PROJECT
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
This software consists of voluntary contributions made by many
individuals on behalf of the JDOM Project and was originally
created by Jason Hunter <jhunter_AT_jdom_DOT_org> and
Brett McLaughlin <brett_AT_jdom_DOT_org>. For more information
on the JDOM Project, please see <http://www.jdom.org/>.
*/
package org.jdom;
import java.util.*;
import org.jdom.Content;
import org.jdom.Element;
import org.jdom.Parent;
/**
* Traverse all a parent's descendants (all children at any level below
* the parent).
*
* @author Bradley S. Huffman
* @author Jason Hunter
* @version $Revision: 1.5 $, $Date: 2004/02/27 11:32:57 $
*/
class DescendantIterator implements Iterator {
private Iterator iterator;
private Iterator nextIterator;
private List stack = new ArrayList();
private static final String CVS_ID =
"@(#) $RCSfile: DescendantIterator.java,v $ $Revision: 1.5 $ $Date: 2004/02/27 11:32:57 $ $Name: jdom_1_0 $";
/**
* Iterator for the descendants of the supplied object.
*
* @param parent document or element whose descendants will be iterated
*/
DescendantIterator(Parent parent) {
if (parent == null) {
throw new IllegalArgumentException("parent parameter was null");
}
this.iterator = parent.getContent().iterator();
}
/**
* Returns true> if the iteration has more {@link Content} descendants.
*
* @return true is the iterator has more descendants
*/
public boolean hasNext() {
if (iterator != null && iterator.hasNext()) return true;
if (nextIterator != null && nextIterator.hasNext()) return true;
if (stackHasAnyNext()) return true;
return false;
}
/**
* Returns the next {@link Content} descendant.
*
* @return the next descendant
*/
public Object next() {
if (!hasNext()) {
throw new NoSuchElementException();
}
// If we need to descend, go for it and record where we are.
// We do the shuffle here on the next next() call so remove() is easy
// to code up.
if (nextIterator != null) {
push(iterator);
iterator = nextIterator;
nextIterator = null;
}
// If this iterator is finished, try moving up the stack
while (!iterator.hasNext()) {
if (stack.size() > 0) {
iterator = pop();
}
else {
throw new NoSuchElementException("Somehow we lost our iterator");
}
}
Content child = (Content) iterator.next();
if (child instanceof Element) {
nextIterator = ((Element)child).getContent().iterator();
}
return child;
}
/**
* Detaches the last {@link org.jdom.Content} returned by the last call to
* next from it's parent. <b>Note</b>: this <b>does not</b> affect
* iteration and all children, siblings, and any node following the
* removed node (in document order) will be visited.
*/
public void remove() {
iterator.remove();
}
private Iterator pop() {
int stackSize = stack.size();
if (stackSize == 0) {
throw new NoSuchElementException("empty stack");
}
return (Iterator) stack.remove(stackSize - 1);
}
private void push(Iterator itr) {
stack.add(itr);
}
private boolean stackHasAnyNext() {
int size = stack.size();
for (int i = 0; i < size; i++) {
Iterator itr = (Iterator) stack.get(i);
if (itr.hasNext()) {
return true;
}
}
return false;
}
}