/* DOM lib */

/* These should be consts, but IE doesn't like that */
var DOM_ELEMENT_NODE = 1;
var DOM_ATTRIBUTE_NODE = 2;
var DOM_TEXT_NODE = 3;
var DOM_CDATA_SECTION_NODE = 4;
var DOM_ENTITY_REFERENCE_NODE = 5;
var DOM_ENTITY_NODE = 6;
var DOM_PROCESSING_INSTRUCTION_NODE = 7;
var DOM_COMMENT_NODE = 8;
var DOM_DOCUMENT_NODE = 9;
var DOM_DOCUMENT_TYPE_NODE = 10;
var DOM_DOCUMENT_FRAGMENT_NODE = 11;
var DOM_NOTATION_NODE = 12;

/**
 * Attaches an event to a node
 * @param node Object node to attach event to
 * @param eventName String name of event (sans "on", eg. "click" not "onclick")
 * @param functionName Function pointer to function that will handle event
 * @return boolean true if event attached, false otherwise
 */
function nodeAttachEvent(node, eventName, functionName)
{
   if (node.addEventListener) 
     {
	node.addEventListener(eventName, functionName, true);
	return true;
     }
   else if (node.attachEvent) 
     {
	node.attachEvent("on" + eventName, functionName);
	return true;
     } 
   else 
     {
	return false;
     }
}

/**
 * Detaches an event from a node
 * @param node Object node to deattach event from
 * @param eventName String name of event (sans "on", eg. "click" not "onclick")
 * @param functionName Function pointer to function that is handling event
 * @return boolean true if event deattached, false otherwise
 */
function nodeDetachEvent(node, eventName, functionName)
{
   if (node.removeEventListener) 
     {
	node.removeEventListener(eventName, functionName, true);
	return true;
     } 
   else if (node.detachEvent) 
     {
	node.detachEvent("on" + eventName, functionName);
	return true;
     } 
   else 
     {
	return false;
     }
}

/**
 * Get CSS classes applied to a node
 * @param object node node to get classes for
 * @return Array array containing a list of classes
 */
function nodeClasses(node)
{
   var classes = new Array();
   
   if (typeof(node) == "string") 
     {
	node = document.getElementById(node);
     }
   
   if (node) 
     {
	classes = String(node.className).split(" ");
     }

   return classes;
}

/**
 * Determines if a node has a specific CSS class applied
 * @param String className name of class
 * @return Boolean true if class is applied, false otherwise
 */
function nodeHasClass(node, className)
{
   var hasClass = false;
   
   if (typeof(node) == "string") 
     {
	node = document.getElementById(node);
     }
   
   if (node) 
     {
	var classes = nodeClasses(node);
	
	if (classes.inArray(className)) 
	  {
	     hasClass = true;
	  }
     }
   return hasClass;
}

/**
 * Applies a CSS class to a node (if it is not already applied) 
 * @param Object node node to apply class to 
 * @param String className name of class
 * to apply @return Boolean true 
 */
function nodeAddClass(node, className)
{
   if (!nodeHasClass(node, className)) 
     {
	var classes = nodeClasses(node);
	classes.push(className);
	
	var newClass = classes.join(" ");
	node.className = newClass;
     }
   
   return true;
}

/**
 * Removes a CSS class from a node
 * @param Object node node to remove class from
 * @param String className name of class to remove
 * @return Boolean true
 */
function nodeRemoveClass(node, className)
{
   if (nodeHasClass(node, className)) 
     {
	var classes = nodeClasses(node);
	classes.remove(className);
	
	var newClass = classes.implode(" ");
	node.className = newClass;
     }
   
   return true;
}

/**
 * Gets first ancestor node by tag name
 * @param Object node node to get ancestor for
 * @param String tagName tag name of ancestor
 * @param String className optional class name that must be applied to ancestor
 * @return Object ancestor node that meets criteria or false if none
 */
function nodeGetAncestorByTagName(node, tagName, className)
{
   var ancestor = false;
   var parent = node.parentNode;
   
   while ((parent) && (!ancestor)) 
     {
	if (String(parent.tagName).toLowerCase() == String(tagName).toLowerCase())
	  {
	     if (className) 
	       {
		  if (nodeHasClass(parent, "tree")) 
		    {
		       ancestor = parent;
		    }
	       } 
	     else 
	       {
		  ancestor = parent;
	       }
	  }
	
	parent = parent.parentNode;
     }
   
   return ancestor;
}

/**
 * Get children of node by tag name
 * @param node Object node to get children from
 * @param tagName String tag name of children to obtain
 * @param depth Number how far to descend into node tree, empty or zero for all
 * @return Array array of child nodes meeting criteria
 */
function nodeChildrenByTagName(node, tagName, depth)
{
   var children = Array();
   
   try 
     {
	
	if (depth > 0) 
	  {
	     var childNodes = node.childNodes;
	     
	     for (var n=0; n < childNodes.length; n++) 
	       {
		  if (String(childNodes[n].tagName).toUpperCase() == String(tagName).toUpperCase()) {
		     children.push(childNodes[n]);
		  }
	       }
	     
	  } 
	else 
	  {
	     children = node.getElementsByTagName(tagName);
	  }
	
     }
   catch (e) 
     {
     }
   
   return children;
}

/**
 * Determines if a node has a particular attribute set
 * Internet explorer sometimes chokes using normal DOM methods
 * @param node Object node to check
 * @param attributeName String name of attribute to check for
 * @return Boolean true if node has attribute defined
 */
function nodeHasAttribute(node, attributeName)
{
   if (node.hasAttribute) 
     {
	return node.hasAttribute(attributeName);
     } 
   else if (node.attributes.length > 0) 
     {
	var rc = false;
	for (var n=0; n < node.attributes.length; n++) 
	  {
	     if (node.attributes[n].nodeName == attributeName) 
	       {
		  if (node.attributes[n].nodeValue) 
		    {
		       rc = true;
		    }
	       }
	  }
	return rc;
     } 
   else 
     {
	return false;
     }
}

/**
 * Determines if node overlaps another node
 * @param a Object first node
 * @param b Object second node
 * @return Boolean true if nodes overlap
 */
function nodesOverlap(a, b)
{
   var overlaps = false;
   
   if (a && b) 
     {
	try 
	  {
	     var at = nodeOffsetTop(a);
	     var al = nodeOffsetLeft(a);
	     var ar = al + parseInt(a.offsetWidth);
	     var ab = at + parseInt(a.offsetHeight);
	     
	     var bt = nodeOffsetTop(b);
	     var bl = nodeOffsetLeft(b);
	     var br = bl + parseInt(b.offsetWidth);
	     var bb = bt + parseInt(b.offsetHeight);
	     
	     if (((bt >= at) && (bt <= ab)) || ((bb >= at) && (bb <= ab)))
	       {
		  if (((bl >= al) && (bl <= ar)) || ((br >= al) && (br <= ar)))
		    {		       
		       overlaps = true;
		    }
		  
	       }
	     
	     var adesc = a.id + " (" + al + "," + at + ") - (" + ar + "," + ab + ")";
	     var bdesc = b.id + " (" + bl + "," + bt + ") - (" + br + "," + bb + ")";
	     
	     //alert(adesc + "\n" + bdesc + "\n" + overlaps);		   
	     
	  }
	 catch (e) 
	  {
	     
	  }
				       
     }
   
   return overlaps;
}

/**
 * Gets total offsetLeft for a node
 * @param node Object node
 * @return Number integer representing offsetLeft from document.body
 */
function nodeOffsetLeft(node)
{
   var offsetLeft = 0;
   
   if (node) 
     {
	offsetLeft = node.offsetLeft;
	
	var parent = node.offsetParent;
	
	while ((parent) && (String(parent.tagName).toLowerCase() != "body")) 
	  {
	     if (parent.offsetLeft) 
	       {
		  offsetLeft += parseInt(parent.offsetLeft);
	       }

	     
	     parent = parent.offsetParent;
	  }
	
     }
   
   return offsetLeft;
}

/**
 * Gets total offsetTop for a node
 * @param node Object node
 * @return Number integer representing offsetTop from document.body
 */
function nodeOffsetTop(node)
{
   var originalNode = node;
   
   var offset = null;
   
   try 
     {
	offset = node.offsetTop;
	
	while ((node = node.offsetParent) != null) 
	  {
	     if ((document.all) && (!window.opera) && (node.id == "pageContent")) 
	       {
		  // no-op
	       }
	      else 
	       {
		  offset += node.offsetTop;
	       }
	     
	  }
	
     }
   catch (e) 
     {
     }
   
   
   if ((document.all) && (!window.opera))
     {
	
	if (document.compatMode) 
	  {
	     if (document.compatMode != "BackCompat" && originalNode.style.position != "absolute") 
	       {
		  try 
		    {
		       offset += parseInt(document.body.currentStyle.marginTop);
		    }
		  catch(e) 
		    {
		    }
	       }
	     
	  }
	
	
     }
   
   
   
   return offset;
}


/* END DOM lib */