/*
*	TABS
*	---------------------------------------------------------------------------
*	Copyright (c) 2008 Dan Peverill
*	http://www.danpeverill.com
*
*	LICENSE
*	---------------------------------------------------------------------------
*	The MIT License
*	http://www.opensource.org/licenses/mit-license.php
*
*	INSALLATION
*	---------------------------------------------------------------------------
*	Tabs are controlled with links. Each link has a target that it is attached to and specified
*	as an #anchor in the href attribute. Example: <a href="#tab">tab</a>. The #anchor
*	is the id of the actual target.
*
*	Tabs can be grouped or single. Grouping tabs you specify the parent
*	class of the tabs with the "tabs" class. For a single tab just add the class "tabs" to it.
*
*	Active tabs given the class "active" by default. Inactive tabs have no class. You may
*	specify the default active/inactive tabs  by adding the class "active" to any of them in
*	your HTML.
*
*	Tab targets are automatically shown and hidden as you click the appropriate tabs. You can control
*	this behavior with callback functions (see below). It is up to you to style the tabs and tab targets
*	with CSS. This script only toggles the active class on tabs and shows/hides the tab targets.
*
*	You may add custom tabs yourself with Tabs.create(tabs, callbacks).
*	
*	Callbacks is an optional argument. Callbacks is an object with two optional properties: click, show.
*	These options are a function that handles the appropriate callback. Each callback can accept
*	two arguments, the click event and the currently active tab target. this refers to the tab.
*	click: This callback is triggered just as a tab is clicked. Returning false cancels the entire event.
*	show: This callback is triggered after the active class and tab has been set, but just before
*		the tab targets are shown.  Returning false means you  handled the showing/hiding of
*		of the tab targets.
*/var Tabs={className:"tabs",activeClass:"active",addLoadEvent:function(event){var oldLoad=window.onload;window.onload=function(){event();if(oldLoad)oldLoad();}},create:function(tabs,callbacks){if(!tabs.length)
this.createSingle(tabs,callbacks);else
this.createGroup(tabs,callbacks);},createSingle:function(tab,callbacks){if(this.Element.hasClass(tab,this.activeClass))
this.Element.show(this.getTarget(tab));this.Element.addClickEvent(tab,function(e){if(!Tabs._callback(this,callbacks,"click",e))
return false;Tabs.Element.toggleClass(this,Tabs.activeClass);if(!Tabs._callback(this,callbacks,"show",e))
return false;Tabs.Element.toggleVisibility(Tabs.getTarget(this));});},createGroup:function(tabs,callbacks){var active;for(var i=0;i<tabs.length;i++){var tab=tabs[i];if(this.Element.hasClass(tab,this.activeClass)){active=tab;this.Element.addClass(tab);this.Element.show(this.getTarget(tab));}
else{this.Element.hide(this.getTarget(tab));}
Tabs.Element.addClickEvent(tab,function(e){if(!Tabs._callback(this,callbacks,"click",e,active))
return false;Tabs.Element.removeClass(active,Tabs.activeClass);Tabs.Element.addClass(this,Tabs.activeClass);var from=active;active=this;if(!Tabs._callback(this,callbacks,"show",e,from))
return false;Tabs.Element.hide(Tabs.getTarget(from));Tabs.Element.show(Tabs.getTarget(this));});}
if(!active){var tab=tabs[0];active=tab;this.Element.addClass(tab,this.activeClass);this.Element.show(this.getTarget(tab));}},_callback:function(element,callbacks,type,e,active){if(callbacks&&callbacks[type]&&callbacks[type].call(element,e,active)===false)
return false;return true;},getTarget:function(tab){var match=/#(.*)$/.exec(tab.href);var target;if(match&&(target=document.getElementById(match[1])))
return target;},getElementsByClassName:function(className,tag){var elements=document.getElementsByTagName(tag||"*");var list=new Array();for(var i=0;i<elements.length;i++){if(this.Element.hasClass(elements[i],this.className))
list.push(elements[i]);}
return list;}};Tabs.Element={addClickEvent:function(element,callback){var oldClick=element.onclick;element.onclick=function(e){callback.call(this,e);if(oldClick)oldClick.call(this,e);return false;}},addClass:function(element,className){element.className+=(element.className?" ":"")+ className;},removeClass:function(element,className){element.className=element.className.replace(new RegExp("(^|\\s)"+ className+"(\\s|$)"),"$1");if(element.className==" ")
element.className="";},hasClass:function(element,className){return element.className&&(new RegExp("(^|\\s)"+ className+"(\\s|$)")).test(element.className);},toggleClass:function(element,className){if(this.hasClass(element,className))
this.removeClass(element,className);else
this.addClass(element,className);},getStyle:function(element,property){if(element.style[property])return element.style[property];if(element.currentStyle)
return element.currentStyle[property];property=property.replace(/([A-Z])/g,"-$1").toLowerCase();var style=document.defaultView.getComputedStyle(element,"");if(style)
return style.getPropertyValue(property);},show:function(element){element.style.display="";if(this.getStyle(element,"display")=="none")
element.style.display="block";},hide:function(element){element.style.display="none";},isVisible:function(element){return this.getStyle(element,"display")!="none";},toggleVisibility:function(element){if(this.isVisible(element))
this.hide(element);else
this.show(element);}};Tabs.addLoadEvent(function(){var elements=Tabs.getElementsByClassName(Tabs.className);for(var i=0;i<elements.length;i++){var element=elements[i];if(element.tagName=="A"){Tabs.create(element);}
else{var tabs=element.getElementsByTagName("a");var group=new Array();for(var t=0;t<tabs.length;t++){if(Tabs.getTarget(tabs[t]))
group.push(tabs[t]);}
if(group.length)Tabs.create(group);}}});