var MerryGoRound=new Class({Implements:[Events,Options],options:{selector:"*",cycle:false,per_page:"auto",page_controls:false,fx_options:{property:"margin-left",link:"cancel"},wrapper_tag:"div",wrapper_options:{"class":"merry-go-round-wrapper",styles:{position:"relative"}},button_event:"click",previous_button_tag:"a",previous_button_options:{html:"prev","class":"merry-go-round-previous",styles:{position:"absolute",left:0}},next_button_tag:"a",next_button_options:{html:"next","class":"merry-go-round-next",styles:{position:"absolute",right:0}},current_page_class:"merry-go-round-current-page",page_controls_tag:"div",page_controls_options:{"class":"merry-go-round-pagination",styles:{overflow:"auto"}}},initialize:function(elem,options){this.setOptions(options);this.inner_element=$(elem);var method=this.inner_element.getParent()?"wraps":"grab";this.element=new Element(this.options.wrapper_tag,this.options.wrapper_options)[method](this.inner_element);this.riders=this.element.getFirst().getChildren(this.options.selector);this.current_index=0;if(this.riders.length===0)return;this.scroll=new Fx.Tween(this.inner_element,this.options.fx_options);this.setup_styles();this.setup_pages();if(this.pages.length>1){this.options.page_controls&&this.setup_page_controls();this.inject_buttons();this.add_events();this.fireEvent("pageShown",[0,this])}return this},setup_styles:function(){this.element.setStyles({height:this.options.wrapper_height||this.riders[0].getHeight(),width:this.options.wrapper_width||this.inner_element.getWidth()});var total_height=0;this.riders.each(function(x){total_height+=x.getWidth()+x.getStyle("margin-left").toInt()+x.getStyle("margin-right").toInt()});this.inner_element.setStyles({width:total_height,overflow:"hidden"})},setup_pages:function(){this.pages=[];if(this.options.per_page=="auto"){var right_edge=this.element.getWidth();this.pages.include(this.riders[0]);for(var i=1,ii=this.riders.length;i<ii;i++){var rider_left=this.riders[i].getPosition(this.inner_element).x,rider_width=this.riders[i].getWidth()+this.riders[i].getStyle("margin-left").toInt()+this.riders[i].getStyle("margin-right").toInt();if(rider_left<right_edge&&rider_left+rider_width>right_edge||i>0&&rider_left>=right_edge&&!this.riders[i-1].retrieve("merry-go-round-page")){this.riders[i].store("merry-go-round-page",true);this.pages.include(this.riders[i]);right_edge=-this._calculate_scroll(this.riders[i])+this.element.getWidth()}}}else if(this.options.per_page===1)this.pages=this.riders;else for(var i=1,ii=this.riders.length;i<ii;i++)i%this.options.per_page===0&&this.pages.include(this.riders[i])},setup_page_controls:function(){this.page_controls=(new Element(this.options.page_controls_tag,this.options.page_controls_options)).adopt(this.pages.map(function(p,i){var tag=this.options.page_controls_tag.test("ul","i")?"li":this.options.page_controls_tag;return new Element(tag,{"class":i===0?this.options.current_page_class:"",events:{click:this.scroll_to_page.bind(this,i)}})},this)).inject(this.element);var total_width=0;this.page_controls.getChildren().each(function(x){total_width+=x.getWidth()+x.getStyle("margin-left").toInt()+x.getStyle("margin-right").toInt()});this.page_controls.setStyle("width",total_width)},inject_buttons:function(){var buttons=[this.previous_button=new Element(this.options.previous_button_tag,this.options.previous_button_options),this.next_button=new Element(this.options.next_button_tag,this.options.next_button_options)];this.element.getParent().adopt(buttons);buttons.each(function(button){button.setStyle("top",button.getParent().getHeight()/2-button.getHeight()/2)});!this.options.cycle&&this.previous_button.setStyle("display","none")},add_events:function(){this.previous_button.addEvent(this.options.button_event,this.previous.bind(this));this.next_button.addEvent(this.options.button_event,this.next.bind(this))},next:function(){this.scroll_to_page(++this.current_index)},previous:function(){this.scroll_to_page(--this.current_index)},_hide_or_show_buttons:function(page_index){if(!this.options.cycle){if(page_index===0)this.previous_button.setStyle("display","none");else this.previous_button.setStyle("display","block");if(page_index+1===this.pages.length)this.next_button.setStyle("display","none");else this.next_button.setStyle("display","block")}},_update_page_controls:function(page_index){$(this.page_controls).getChildren().removeClass(this.options.current_page_class)[page_index].addClass(this.options.current_page_class)},_calculate_scroll:function(elem){return -elem.getPosition(this.inner_element).x+elem.getStyle("margin-left").toInt()+this.inner_element.getStyle("padding-left").toInt()},scroll_to_page:function(page_index){if(page_index<0)page_index=this.pages.length+page_index;else page_index=page_index%this.pages.length;this.current_index=page_index;this.fireEvent("pageShown",[page_index,this]);this._hide_or_show_buttons(page_index);this.options.page_controls&&this._update_page_controls(page_index);this.scroll.start(this._calculate_scroll(this.pages[page_index]))}})