treewalkerimpl.java

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/*
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 1999-2002 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 [e-mail].
 *
 * 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.apache.org.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

package com.sun.org.apache.xerces.internal.dom;

import org.w3c.dom.DOMException;
import org.w3c.dom.Node;
import org.w3c.dom.traversal.NodeFilter;
import org.w3c.dom.traversal.TreeWalker;

/** This class implements the TreeWalker interface. */
/**
 * @version $Id: TreeWalkerImpl.java,v 1.8 2003/07/29 18:29:40 elena Exp $
 */

public class TreeWalkerImpl implements TreeWalker {
    
    //
    // Data
    //
    
    /** When TRUE, the children of entites references are returned in the iterator. */
    private boolean fEntityReferenceExpansion = false;
    /** The whatToShow mask. */
    int fWhatToShow = NodeFilter.SHOW_ALL;
    /** The NodeFilter reference. */
    NodeFilter fNodeFilter;
    /** The current Node. */
    Node fCurrentNode;
    /** The root Node. */
    Node fRoot;
    
    //
    // Implementation Note: No state is kept except the data above
    // (fWhatToShow, fNodeFilter, fCurrentNode, fRoot) such that 
    // setters could be created for these data values and the 
    // implementation will still work.
    
    
    // 
    // Constructor
    //
    
    /** Public constructor */
    public TreeWalkerImpl(Node root, 
                          int whatToShow, 
                          NodeFilter nodeFilter,
                          boolean entityReferenceExpansion) {
        fCurrentNode = root;
        fRoot = root;
        fWhatToShow = whatToShow;
        fNodeFilter = nodeFilter;
        fEntityReferenceExpansion = entityReferenceExpansion;
    }
    
    public Node getRoot() {
	return fRoot;
    }

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

    public void setWhatShow(int whatToShow){
        fWhatToShow = whatToShow;
    }
    /** Return the NodeFilter */
    public NodeFilter         getFilter() {
        return fNodeFilter;
    }
    
    /** Return whether children entity references are included in the iterator. */
    public boolean            getExpandEntityReferences() {
        return fEntityReferenceExpansion;
    }
            
    /** Return the current Node. */
    public Node               getCurrentNode() {
        return fCurrentNode;
    }
    /** Return the current Node. */
    public void               setCurrentNode(Node node) {
        if (node == null) {
            String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NOT_SUPPORTED_ERR", null);
              throw new DOMException(DOMException.NOT_SUPPORTED_ERR, msg);
        }

        fCurrentNode = node;
    }
    
    /** Return the parent Node from the current node, 
     *  after applying filter, whatToshow.
     *  If result is not null, set the current Node.
     */
    public Node               parentNode() {

        if (fCurrentNode == null) return null;
                
        Node node = getParentNode(fCurrentNode);
        if (node !=null) {
            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.
     */
    public Node               firstChild() {
        
        if (fCurrentNode == null) return null;
                
        Node node = getFirstChild(fCurrentNode);
        if (node !=null) {
            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.
     */
    public Node               lastChild() {

        if (fCurrentNode == null) return null;
                
        Node node = getLastChild(fCurrentNode);
        if (node !=null) {
            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.
     */
    public Node               previousSibling() {

        if (fCurrentNode == null) return null;
                
        Node node = getPreviousSibling(fCurrentNode);
        if (node !=null) {
            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.
     */
    public Node               nextSibling(){
        if (fCurrentNode == null) return null;
                
        Node node = getNextSibling(fCurrentNode);
        if (node !=null) {
            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.
     */
    public Node               previousNode() {
        Node result;
        
        if (fCurrentNode == null) return null;
        
        // get sibling
        result = getPreviousSibling(fCurrentNode);
        if (result == null) {
            result = getParentNode(fCurrentNode);
            if (result != null) {
                fCurrentNode = result;
                return fCurrentNode;
            } 
            return null;
        }
        
        // get the lastChild of result.
        Node lastChild  = getLastChild(result);
        
        Node prev = lastChild ;
        while (lastChild != null) {
          prev = lastChild ;
          lastChild = getLastChild(prev) ;
        }

        lastChild = prev ;
        
        // if there is a lastChild which passes filters return it.
        if (lastChild != null) {
            fCurrentNode = lastChild;
            return fCurrentNode;
        } 
        
        // otherwise return the previous sibling.
        if (result != null) {
            fCurrentNode = result;
            return fCurrentNode;
        }
        
        // otherwise return null.
        return null;
    }
    
    /** Return the next Node from the current node, 
     *  after applying filter, whatToshow.
     *  If result is not null, set the current Node.
     */
    public Node               nextNode() {