/* 
 * Developer(s): sgray
 * 
 * Register hash change events this way
 * $(window).bind('hashChange',function(){ yourEvent(); });
 * your event should set UrlHashWatcher.ajaxActive=1 during an ajax request,
 * and should call UrlHashWatcher.setNewPageHash(newHash) when complete 
 */

var UrlHashWatcher = {
	
	intervalTime: 500,
	ajaxActive: 0,
	currentHash:'',	
	lastHash:'',		
	settingHash: false,
	init: function(){
		if (this.initialized || ($.browser.msie && $.browser.version.substr(0,1)<7)) return;
		
		this.timeout = setTimeout( function (){ UrlHashWatcher.changeCheck(); }, this.intervalTime);
		
		this.initialized=1;
	},
		
	changeCheck: function(){ 
		var hash = window.location.hash;
		hash = this.stripHash(hash);
		
		if (hash!=this.lastHash) {
					
			this.currentHash=hash;
			
		    	$(window).trigger('hashChange');
		    	
		    	this.lastHash=hash;
		}
		
		this.timeout = setTimeout( function(){ UrlHashWatcher.changeCheck(); }, this.intervalTime);
	}, 
	
	setNewPageHash: function(newHash){
		newHash = this.stripHash(newHash);
		
		if(this.lastHash !== newHash) {		
			this.lastHash=newHash; 
			window.location.hash = newHash;
		}
		
		this.ajaxActive = false;
	},
	
	stripHash : function(hash){
		if(hash.indexOf('#') == 0) {
			hash = hash.split('#')[1];
		}
		return hash;
	}		
}