src/dom/TreeWalkerImpl.cpp

/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999 The Apache Software Foundation.  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 following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Xerces" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact apache\@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * 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 APACHE SOFTWARE FOUNDATION OR
 * ITS 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 Apache Software Foundation, and was
 * originally based on software copyright (c) 1999, International
 * Business Machines, Inc., http://www.ibm.com .  For more information
 * on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
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/**
 * $Log$
 * Revision 1.3  1999/11/30 21:16:26  roddey
 * Changes to add the transcode() method to DOMString, which returns a transcoded
 * version (to local code page) of the DOM string contents. And I changed all of the
 * exception 'throw by pointer' to 'throw by value' style.
 *
 * Revision 1.2  1999/11/23 01:48:17  rahulj
 * Changed 0L to 0. CC under HPUX is happy now.
 *
 * Revision 1.1.1.1  1999/11/09 01:09:20  twl
 * Initial checkin
 *
 * Revision 1.2  1999/11/08 20:44:33  rahul
 * Swat for adding in Product name and CVS comment log variable.
 *
 */

#include "TreeWalkerImpl.hpp"
#include "DOM_Document.hpp"
#include "DOM_DOMException.hpp"
#include "DocumentImpl.hpp"


/** constructor */
TreeWalkerImpl::TreeWalkerImpl (DOM_Node root, int whatToShow, DOM_NodeFilter nodeFilter, NodeFilterImpl* twi) {
    fCurrentNode = root;
    fRoot = root;
    fWhatToShow = whatToShow;
    fNodeFilter = nodeFilter;
    nodeRefCount = 0;
	fDetached = false;

    if (twi != 0L) {
        DOM_NodeFilter nf(twi);
        fNodeFilter = nf;
    }
}


TreeWalkerImpl::TreeWalkerImpl (const TreeWalkerImpl& twi) {
    fCurrentNode = twi.fCurrentNode;
    fRoot = twi.fRoot;
    fWhatToShow = twi.fWhatToShow;
    fNodeFilter = twi.fNodeFilter;
    nodeRefCount = 0;
	fDetached = false;
}


TreeWalkerImpl& TreeWalkerImpl::operator= (const TreeWalkerImpl& twi) {
    if (this != &twi)
    {
        fCurrentNode = twi.fCurrentNode;
        fRoot = twi.fRoot;
        fWhatToShow = twi.fWhatToShow;
        fNodeFilter = twi.fNodeFilter;
		fDetached = twi.fDetached;
    }

    return *this;
}


void TreeWalkerImpl::detach ()
{
	fDetached = true;
}


void TreeWalkerImpl::unreferenced()
{
    DOM_Document doc = fRoot.getOwnerDocument();
    DocumentImpl* impl;

    if (! doc.isNull()) {
        impl = (DocumentImpl *) doc.fImpl;
    }
    else
        impl = (DocumentImpl *) fRoot.fImpl;

    if (impl->treeWalkers != 0L) {
        int i;
        int sz = impl->treeWalkers->size();
        for (i = 0; i < sz; i++)
            if (impl->treeWalkers->elementAt(i) == this) {
                impl->treeWalkers->removeElementAt(i);
                break;
            }
    }

    delete this;
}


/** Return the whatToShow value */
int TreeWalkerImpl::getWhatToShow () {
    return fWhatToShow;
}


/** Return the NodeFilter */
DOM_NodeFilter TreeWalkerImpl::getFilter () {
    return fNodeFilter;
}


/** Return the current Node. */
DOM_Node TreeWalkerImpl::getCurrentNode () {
	if (fDetached)
		throw DOM_DOMException(DOM_DOMException::INVALID_STATE_ERR, null);

    return fCurrentNode;
}


/** Return the current Node. */
void TreeWalkerImpl::setCurrentNode (DOM_Node node) {
	if (fDetached)
		throw DOM_DOMException(DOM_DOMException::INVALID_STATE_ERR, null);

    fCurrentNode = node;
}


/** Return the parent Node from the current node,
 *  after applying filter, whatToshow.
 *  If result is not null, set the current Node.
 */
DOM_Node TreeWalkerImpl::parentNode () {
	if (fDetached)
		throw DOM_DOMException(DOM_DOMException::INVALID_STATE_ERR, null);

	DOM_Node result;

    if (fCurrentNode.isNull()) return result;

    DOM_Node node = getParentNode(fCurrentNode);
    if (node != 0) {
        fCurrentNode = node;
    }
    return node;

}


/** Return the first child Node from the current node,
 *  after applying filter, whatToshow.
 *  If result is not null, set the current Node.
 */
DOM_Node TreeWalkerImpl::firstChild () {
	if (fDetached)
		throw DOM_DOMException(DOM_DOMException::INVALID_STATE_ERR, null);

	DOM_Node result;

    if (fCurrentNode.isNull()) return result;

    DOM_Node node = getFirstChild(fCurrentNode);
    if (! node.isNull()) {
        fCurrentNode = node;
    }
    return node;
}


/** Return the last child Node from the current node,
 *  after applying filter, whatToshow.
 *  If result is not null, set the current Node.
 */
DOM_Node TreeWalkerImpl::lastChild () {
	if (fDetached)
		throw DOM_DOMException(DOM_DOMException::INVALID_STATE_ERR, null);
		
	DOM_Node result;

    if (fCurrentNode.isNull()) return result;

    DOM_Node node = getLastChild(fCurrentNode);
    if (! node.isNull()) {
        fCurrentNode = node;
    }
    return node;
}


/** Return the previous sibling Node from the current node,
 *  after applying filter, whatToshow.
 *  If result is not null, set the current Node.
 */

DOM_Node TreeWalkerImpl::previousSibling () {
	if (fDetached)
		throw DOM_DOMException(DOM_DOMException::INVALID_STATE_ERR, null);
	
	DOM_Node result;

    if (fCurrentNode.isNull()) return result;

    DOM_Node node = getPreviousSibling(fCurrentNode);
    if (! node.isNull()) {
        fCurrentNode = node;
    }
    return node;
}


/** Return the next sibling Node from the current node,
 *  after applying filter, whatToshow.
 *  If result is not null, set the current Node.
 */

DOM_Node TreeWalkerImpl::nextSibling () {
	if (fDetached)
		throw DOM_DOMException(DOM_DOMException::INVALID_STATE_ERR, null);
		
	DOM_Node result;

    if (fCurrentNode.isNull()) return result;

    DOM_Node node = getNextSibling(fCurrentNode);
    if (! node.isNull()) {
        fCurrentNode = node;
    }
    return node;
}


/** Return the previous Node from the current node,
 *  after applying filter, whatToshow.
 *  If result is not null, set the current Node.
 */

DOM_Node TreeWalkerImpl::previousNode () {
	if (fDetached)
		throw DOM_DOMException(DOM_DOMException::INVALID_STATE_ERR, null);

    DOM_Node result;

    if (fCurrentNode.isNull()) return result;

    // get sibling
    result = getPreviousSibling(fCurrentNode);
    if (result.isNull()) {
        result = getParentNode(fCurrentNode);
        if (! result.isNull()) {
            fCurrentNode = result;
            return fCurrentNode;
        }
        return result;
    }

    // get the lastChild of result.
    DOM_Node lastChild  = getLastChild(result);

    // if there is a lastChild which passes filters return it.
    if (! lastChild.isNull()) {
        fCurrentNode = lastChild;
        return fCurrentNode;
    }

    // otherwise return the previous sibling.
    if (! result.isNull()) {
        fCurrentNode = result;
        return fCurrentNode;
    }

    // otherwise return null.
    return result;
}


/** Return the next Node from the current node,
 *  after applying filter, whatToshow.
 *  If result is not null, set the current Node.
 */

DOM_Node TreeWalkerImpl::nextNode () {
	if (fDetached)
		throw DOM_DOMException(DOM_DOMException::INVALID_STATE_ERR, null);
	
	DOM_Node result;

    if (fCurrentNode.isNull()) return result;

    result = getFirstChild(fCurrentNode);

    if (! result.isNull()) {
        fCurrentNode = result;
        return result;
    }

    result = getNextSibling(fCurrentNode);

    if (! result.isNull()) {
        fCurrentNode = result;
        return result;
    }

    // return parent's 1st sibling.
    DOM_Node parent = getParentNode(fCurrentNode);
    while (! parent.isNull()) {
        result = getNextSibling(parent);
        if (! result.isNull()) {
            fCurrentNode = result;
            return result;
        } else {
            parent = getParentNode(parent);
        }
    }

    // end , return null
    return result;
}


/** Internal function.
 *  Return the parent Node, from the input node
 *  after applying filter, whatToshow.
 *  The current node is not consulted or set.
 */

DOM_Node TreeWalkerImpl::getParentNode (DOM_Node node) {
	if (fDetached)
		throw DOM_DOMException(DOM_DOMException::INVALID_STATE_ERR, null);
	
	DOM_Node result;

    if (node.isNull() || node == fRoot) return result;

    DOM_Node newNode = node.getParentNode();
    if (newNode.isNull())  return result;

    int accept = acceptNode(newNode);

    if (accept == DOM_NodeFilter::ACCEPT)
        return newNode;
    else
    {
        return getParentNode(newNode);
    }


}


/** Internal function.
 *  Return the nextSibling Node, from the input node
 *  after applying filter, whatToshow.
 *  The current node is not consulted or set.
 */

DOM_Node TreeWalkerImpl::getNextSibling (DOM_Node node) {
	if (fDetached)
		throw DOM_DOMException(DOM_DOMException::INVALID_STATE_ERR, null);
	
	DOM_Node result;

    if (node.isNull() || node == fRoot) return result;

    DOM_Node newNode = node.getNextSibling();
    if (newNode.isNull()) {

        newNode = node.getParentNode();

        if (newNode.isNull() || node == fRoot)  return result;

        int parentAccept = acceptNode(newNode);

        if (parentAccept == DOM_NodeFilter::SKIP) {
            return getNextSibling(newNode);
        }

        return result;
    }

    int accept = acceptNode(newNode);

    if (accept == DOM_NodeFilter::ACCEPT)
        return newNode;
    else
    if (accept == DOM_NodeFilter::SKIP) {
        DOM_Node fChild =  getFirstChild(newNode);
        if (fChild.isNull()) {
            return getNextSibling(newNode);
        }
        return fChild;
    }
    else
    {
        return getNextSibling(newNode);
    }

}


/** Internal function.
 *  Return the previous sibling Node, from the input node
 *  after applying filter, whatToshow.
 *  The current node is not consulted or set.
 */

DOM_Node TreeWalkerImpl::getPreviousSibling (DOM_Node node) {
	if (fDetached)
		throw DOM_DOMException(DOM_DOMException::INVALID_STATE_ERR, null);
		
	DOM_Node result;

    if (node.isNull() || node == fRoot) return result;

    DOM_Node newNode = node.getPreviousSibling();
    if (newNode.isNull()) {

        newNode = node.getParentNode();
        if (newNode.isNull() || node == fRoot)  return result;

        int parentAccept = acceptNode(newNode);

        if (parentAccept == DOM_NodeFilter::SKIP) {
            return getPreviousSibling(newNode);
        }

        return result;
    }

    int accept = acceptNode(newNode);

    if (accept == DOM_NodeFilter::ACCEPT)
        return newNode;
    else
    if (accept == DOM_NodeFilter::SKIP) {
        DOM_Node fChild =  getLastChild(newNode);
        if (fChild.isNull()) {
            return getPreviousSibling(newNode);
        }
        return fChild;
    }
    else
    {
        return getPreviousSibling(newNode);
    }

}


/** Internal function.
 *  Return the first child Node, from the input node
 *  after applying filter, whatToshow.
 *  The current node is not consulted or set.
 */

DOM_Node TreeWalkerImpl::getFirstChild (DOM_Node node) {
	if (fDetached)
		throw DOM_DOMException(DOM_DOMException::INVALID_STATE_ERR, null);
		
	DOM_Node result;

    if (node.isNull()) return result;

    DOM_Node newNode = node.getFirstChild();
    if (newNode.isNull())  return result;

    int accept = acceptNode(newNode);

    if (accept == DOM_NodeFilter::ACCEPT)
        return newNode;
    else
    if (accept == DOM_NodeFilter::SKIP
        && newNode.hasChildNodes())
    {
        return getFirstChild(newNode);
    }
    else
    {
        return getNextSibling(newNode);
    }
}


/** Internal function.
 *  Return the last child Node, from the input node
 *  after applying filter, whatToshow.
 *  The current node is not consulted or set.
 */

DOM_Node TreeWalkerImpl::getLastChild (DOM_Node node) {
	if (fDetached)
		throw DOM_DOMException(DOM_DOMException::INVALID_STATE_ERR, null);

	DOM_Node result;

    if (node.isNull()) return result;

    DOM_Node newNode = node.getLastChild();
    if (newNode.isNull())  return result;

    int accept = acceptNode(newNode);

    if (accept == DOM_NodeFilter::ACCEPT)
        return newNode;
    else
    if (accept == DOM_NodeFilter::SKIP
        && newNode.hasChildNodes())
    {
        return getLastChild(newNode);
    }
    else
    {
        return getPreviousSibling(newNode);
    }


}


/** The node is accepted if it passes the whatToShow and the filter. */

short TreeWalkerImpl::acceptNode (DOM_Node node) {
	if (fDetached)
		throw DOM_DOMException(DOM_DOMException::INVALID_STATE_ERR, null);

    if (fNodeFilter == 0) {
        if ( ( fWhatToShow & (1 << (node.getNodeType() - 1))) != 0)
        {
            return DOM_NodeFilter::ACCEPT;
        }
        else
        {
            return DOM_NodeFilter::SKIP;
        }
    } else {
        // REVISIT: This logic is unclear from the spec!
        if ((fWhatToShow & (1 << (node.getNodeType() - 1))) != 0 ) {
            return fNodeFilter.acceptNode(node);
        } else {
            // what to show has failed!
            if (fNodeFilter.acceptNode(node) == DOM_NodeFilter::REJECT) {
                return DOM_NodeFilter::REJECT;
            } else {
                return DOM_NodeFilter::SKIP;
            }
        }
    }
}