public DeepNodeListImpl(NodeImpl rootNode,
    String tagName) 
{
    //
    // Constructors
    //
        this.rootNode = rootNode;
        this.tagName  = tagName;
        nodes = new Vector();
}

Constructor.

 public DeepNodeListImpl(NodeImpl rootNode,
    String nsName,
    String tagName) 
{
        this(rootNode, tagName);
        this.nsName = (nsName != null && !nsName.equals("")) ? nsName : null;
        enableNS = true;
}

Constructor for Namespace support.

 public int getLength() 
{
        // Preload all matching elements. (Stops when we run out of subtree!)
        item(java.lang.Integer.MAX_VALUE);
        return nodes.size();
}

Returns the length of the node list.

 public Node item(int index) 
{
    	Node thisNode;
        // Tree changed. Do it all from scratch!
    	if(rootNode.changes() != changes) {
            nodes   = new Vector();     
            changes = rootNode.changes();
    	}
        // In the cache
    	if (index <  nodes.size())      
    	    return (Node)nodes.elementAt(index);
        // Not yet seen
    	else {
            // Pick up where we left off (Which may be the beginning)
    		if (nodes.size() == 0)     
    		    thisNode = rootNode;
    		else
    		    thisNode=(NodeImpl)(nodes.lastElement());
    		// Add nodes up to the one we're looking for
    		while(thisNode != null && index  >= nodes.size()) {
    			thisNode=nextMatchingElementAfter(thisNode);
    			if (thisNode != null)
    			    nodes.addElement(thisNode);
    		    }
            // Either what we want, or null (not avail.)
		    return thisNode;           
	    }
}

Returns the node at the specified index.

 protected Node nextMatchingElementAfter(Node current) 
{
	    Node next;
	    while (current != null) {
		    // Look down to first child.
		    if (current.hasChildNodes()) {
			    current = (current.getFirstChild());
		    }
		    // Look right to sibling (but not from root!)
		    else if (current != rootNode && null != (next = current.getNextSibling())) {
				current = next;
			}
			// Look up and right (but not past root!)
			else {
				next = null;
				for (; current != rootNode; // Stop when we return to starting point
					current = current.getParentNode()) {
					next = current.getNextSibling();
					if (next != null)
						break;
				}
				current = next;
			}
			// Have we found an Element with the right tagName?
			// ("*" matches anything.)
		    if (current != rootNode 
		        && current != null
		        && current.getNodeType() ==  Node.ELEMENT_NODE) {
			if (!enableNS) {
			    if (tagName.equals("*") ||
				((ElementImpl) current).getTagName().equals(tagName))
			    {
				return current;
			    }
			} else {
			    // DOM2: Namespace logic. 
			    if (tagName.equals("*")) {
				if (nsName != null && nsName.equals("*")) {
				    return current;
				} else {
				    ElementImpl el = (ElementImpl) current;
				    if ((nsName == null
					 && el.getNamespaceURI() == null)
					|| (nsName != null
					    && nsName.equals(el.getNamespaceURI())))
				    {
					return current;
				    }
				}
			    } else {
				ElementImpl el = (ElementImpl) current;
				if (el.getLocalName() != null
				    && el.getLocalName().equals(tagName)) {
				    if (nsName != null && nsName.equals("*")) {
					return current;
				    } else {
					if ((nsName == null
					     && el.getNamespaceURI() == null)
					    || (nsName != null &&
						nsName.equals(el.getNamespaceURI())))
					{
					    return current;
					}
				    }
				}
			    }
			}
		    }
		// Otherwise continue walking the tree
	    }
	    // Fell out of tree-walk; no more instances found
	    return null;
}

Iterative tree-walker. When you have a Parent link, there's often no need to resort to recursion. NOTE THAT only Element nodes are matched since we're specifically supporting getElementsByTagName().