<?php
/*
 *  $Id: PreOrderNodeIterator.php 536 2007-01-10 14:30:38Z heltem $
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS 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 COPYRIGHT
 * OWNER OR 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
 * and is licensed under the LGPL. For more information please see
 * <http://propel.phpdb.org>.
 */

/**
 * Pre-order node iterator for Node objects.
 *
 * @author     Kaspars Jaudzems <hide@address.com> (Propel)
 * @author     Dave Lawson <hide@address.com>
 * @version    $Revision: 536 $
 * @package    propel.om
 */
class PreOrderNodeIterator
{
  var $topNode = null;

  var $curNode = null;

  var $querydb = false;

  function PreOrderNodeIterator(&$node, &$opts)
  {
	$this->topNode =& $node;
	$this->curNode =& $node;

	if (isset($opts['querydb'])) {
	  $this->querydb =& $opts['querydb'];
	}
  }

  function rewind()
  {
	$this->curNode =& $this->topNode;
  }

  function valid()
  {
	return ($this->curNode !== null);
  }

  function & current()
  {
	return $this->curNode;
  }

  function key()
  {
	return $this->curNode->getNodePath();
  }

  function & next()
  {
	if ($this->valid())
	{
	  $nextNode =& $this->curNode->getFirstChildNode($this->querydb);

	  while ($nextNode === null)
	  {
		if ($this->curNode === null || $this->curNode->equals($this->topNode)) {
		  break;
		}

		$nextNode =& $this->curNode->getSiblingNode(false, $this->querydb);

		if ($nextNode === null) {
		  $this->curNode =& $this->curNode->getParentNode($this->querydb);
		}
	  }

	  $this->curNode =& $nextNode;
	}

	return $this->curNode;
  }

}