/* A More Accessible Map http://www.alistapart.com/articles/cssmaps */
var mapMaker =
{
	offsetX: -16, // tooltip X offset
	offsetY: 16,  // tooltip Y offset
	element: false,
	DLs:     false,
	DTs:     false,
	on:      false,
	/* constructor - sets events */
	init: function()
	{
		var i = 0;
		var ii = 0;
		var currentLocation = 0;
		mapMaker.DLs = document.getElementsByTagName('dl');

		// Only loop thru items once
		if (mapMaker.on == false)
		{
			// Loop through each DL on page
			while (mapMaker.DLs.length > i)
			{
				// Only affect DLs with a class of 'map'
				if (mapMaker.DLs[i].className == 'map')
				{
					// Change map DL class, this way map is text only without javascript enabled
					mapMaker.DLs[i].className = 'map on';

					// Remove any white space
					mapMaker.stripWhitespace(mapMaker.DLs[i]);
					
					// Get DTs that are children of DL
					mapMaker.DTs = mapMaker.DLs[i].getElementsByTagName('dt');
					
					// Loop thru all DT elements
					while (mapMaker.DTs.length > ii)
					{
						// Remove any white space
						mapMaker.stripWhitespace(mapMaker.DTs[ii]);
						
						// Current Location
						currentLocation = mapMaker.DTs[ii].firstChild;

						// Add events to links
						mapMaker.addEvt(currentLocation, 'mouseover', mapMaker.showTooltip); // Displays tooltip on mouse over
						mapMaker.addEvt(currentLocation, 'mouseout', mapMaker.hideTooltip); // Hide tooltip on mouse out
						mapMaker.addEvt(currentLocation, 'focus', mapMaker.showTooltip); // Display tooltip on focus, for added keyboard accessibility
						mapMaker.addEvt(currentLocation, 'blur', mapMaker.hideTooltip); // Hide tooltip on focus, for added keyboard accessibility

						ii ++;
					}

					ii = 0;
				}

				i ++;
			}

			mapMaker.on = true;
		}
	},
	/* SHOW TOOLTIP */
	showTooltip: function()
	{
		var evt = this;
		var i = 0;
		
		//Find DD to display - based on currently hovered anchor move to parent DT then next sibling DD
		var objid = evt.parentNode.nextSibling;
		mapMaker.element = objid;//set for the hideTooltip
		
		//get width and height of background map
		var mapWidth  = objid.parentNode.offsetWidth;
		var mapHeight = objid.parentNode.offsetHeight;
		
		//get width and height of the DD
		var toopTipWidth = objid.offsetWidth;
		var toopTipHeight = objid.offsetHeight;
		
		//figure out where tooltip should be places based on point location
		var newX = evt.offsetLeft + mapMaker.offsetX;
		var newY = evt.offsetTop + mapMaker.offsetY;
		
		//check if tooltip fits map width 
		if ((newX + toopTipWidth) > mapWidth)
		{
			objid.style.left = newX-toopTipWidth-24 + 'px';
		}
		else
		{
			objid.style.left = newX + 'px';
		}
		
		// Check if tooltip fits map height 
		if ((newY + toopTipHeight) > mapHeight)
		{
			objid.style.top = newY - toopTipHeight - 14 + 'px';
		}
		else
		{
			objid.style.top = newY + 'px';
		}
	},
	/* HIDE TOOLTIP */
	hideTooltip: function()
	{
		mapMaker.element.style.left = '-9999px';
	},
	addEvt: function(element, type, handler)
	{
		// assign each event handler a unique ID
		if (!handler.$$guid) handler.$$guid = mapMaker.addEvt.guid++;
		
		// create a hash table of event types for the element
		if (!element.events) element.events = {};
		
		// create a hash table of event handlers for each element/event pair
		var handlers = element.events[type];
		
		if (!handlers)
		{
			handlers = element.events[type] = {};
			
			// store the existing event handler (if there is one)
			if (element["on" + type])
			{
				handlers[0] = element["on" + type];
			}
		}
		
		// store the event handler in the hash table
		handlers[handler.$$guid] = handler;
		
		// assign a global event handler to do all the work
		element["on" + type] = mapMaker.handleEvent;
	},
	handleEvent: function(event)
	{
		var returnValue = true;
		
		// grab the event object (IE uses a global event object)
		event = event || mapMaker.fixEvent(window.event);
		
		// get a reference to the hash table of event handlers
		var handlers = this.events[event.type];

		// execute each event handler
		for (var i in handlers)
		{
			this.$$handleEvent = handlers[i];
			
			if (this.$$handleEvent(event) === false) 
			{
				returnValue = false;
			}
		}
		
		return returnValue;
	},
	fixEvent: function(event)
	{
		// add W3C standard event methods
		event.preventDefault = mapMaker.fixEvent.preventDefault;
		event.stopPropagation = mapMaker.fixEvent.stopPropagation;
		
		return event;
	},
	stripWhitespace: function(el)
	{
		for(var i = 0; i < el.childNodes.length; i++)
		{
			var node = el.childNodes[i];
			if (node.nodeType == 3 && !/\S/.test(node.nodeValue)) 
			{
				node.parentNode.removeChild(node);
			}
		}
	}
};

mapMaker.fixEvent.preventDefault = function() { this.returnValue = false; };
mapMaker.fixEvent.stopPropagation = function() { this.cancelBubble = true; };
mapMaker.addEvt.guid = 1;

/* Load script for Mozilla */
if (document.addEventListener)
{
	document.addEventListener("DOMContentLoaded", mapMaker.init, null);
};

/* Load script for other browsers */
mapMaker.addEvt( window, 'load', mapMaker.init);