if(typeof(Prototype)=="undefined")
throw"Control.ScrollBar requires Prototype to be loaded.";if(typeof(Control.Slider)=="undefined")
throw"Control.ScrollBar requires Control.Slider to be loaded.";if(typeof(Object.Event)=="undefined")
throw"Control.ScrollBar requires Object.Event to be loaded.";Control.ScrollBar=Class.create({initialize:function(container,track,options){this.enabled=false;this.notificationTimeout=false;this.container=$(container);this.boundMouseWheelEvent=this.onMouseWheel.bindAsEventListener(this);this.boundResizeObserver=this.onWindowResize.bind(this);this.track=$(track);this.handle=this.track.firstDescendant().nextSiblings()[0];this.handle_top=this.handle.firstDescendant();this.handle_middle=this.handle.firstDescendant().nextSiblings()[0];this.handle_bottom=this.handle.firstDescendant().nextSiblings()[1];this.options=Object.extend({active_class_name:'scrolling',apply_active_class_name_to:this.container,notification_timeout_length:125,handle_minimum_height:25,scroll_to_smoothing:0.01,scroll_to_steps:15,proportional:true,slider_options:{}},options||{});this.slider=new Control.Slider(this.handle,this.track,Object.extend({axis:'vertical',onSlide:this.onChange.bind(this),onChange:this.onChange.bind(this)},this.options.slider_options));this.recalculateLayout();Event.observe(window,'resize',this.boundResizeObserver);this.handle.observe('mousedown',function(){if(this.auto_sliding_executer)
this.auto_sliding_executer.stop();}.bind(this));},destroy:function(){Event.stopObserving(window,'resize',this.boundResizeObserver);},enable:function(){this.enabled=true;this.container.observe('mouse:wheel',this.boundMouseWheelEvent);this.slider.setEnabled();this.track.show();if(this.options.active_class_name)
$(this.options.apply_active_class_name_to).addClassName(this.options.active_class_name);this.notify('enabled');},disable:function(){this.enabled=false;this.container.stopObserving('mouse:wheel',this.boundMouseWheelEvent);this.slider.setDisabled();this.track.hide();if(this.options.active_class_name)
$(this.options.apply_active_class_name_to).removeClassName(this.options.active_class_name);this.notify('disabled');this.reset();},reset:function(){this.slider.setValue(0);},recalculateLayout:function(){if(this.container.scrollHeight<=this.container.offsetHeight)
this.disable();else{this.slider.trackLength=this.slider.maximumOffset()-this.slider.minimumOffset();if(this.options.proportional){this.handle.style.height=Math.max(this.container.offsetHeight*(this.container.offsetHeight/this.container.scrollHeight),this.options.handle_minimum_height)+'px';this.slider.handleLength=this.handle.style.height.replace(/px/,'');this.handle_middle.style.height=this.slider.handleLength-8+'px';}
this.enable();}},onWindowResize:function(){this.recalculateLayout();this.scrollBy(0);},onMouseWheel:function(event){if(this.auto_sliding_executer)
this.auto_sliding_executer.stop();this.slider.setValueBy(-(event.memo.delta/20));event.stop();return false;},onChange:function(value){this.container.scrollTop=Math.round(value/this.slider.maximum*(this.container.scrollHeight-this.container.offsetHeight));if(this.notification_timeout)
window.clearTimeout(this.notificationTimeout);this.notificationTimeout=window.setTimeout(function(){this.notify('change',value);}.bind(this),this.options.notification_timeout_length);},getCurrentMaximumDelta:function(){return this.slider.maximum*(this.container.scrollHeight-this.container.offsetHeight);},getDeltaToElement:function(element){return this.slider.maximum*((element.positionedOffset().top+(element.getHeight()/2))-(this.container.getHeight()/2));},scrollTo:function(y,animate){var current_maximum_delta=this.getCurrentMaximumDelta();if(y=='top')
y=0;else if(y=='bottom')
y=current_maximum_delta;else if(typeof(y)!="number")
y=this.getDeltaToElement($(y));if(this.enabled){y=Math.max(0,Math.min(y,current_maximum_delta));if(this.auto_sliding_executer)
this.auto_sliding_executer.stop();var target_value=y/current_maximum_delta;var original_slider_value=this.slider.value;var delta=(target_value-original_slider_value)*current_maximum_delta;if(animate){this.auto_sliding_executer=new PeriodicalExecuter(function(){if(Math.round(this.slider.value*100)/100<Math.round(target_value*100)/100||Math.round(this.slider.value*100)/100>Math.round(target_value*100)/100){this.scrollBy(delta/this.options.scroll_to_steps);}else{this.auto_sliding_executer.stop();this.auto_sliding_executer=null;if(typeof(animate)=="function")
animate();}}.bind(this),this.options.scroll_to_smoothing);}else
this.scrollBy(delta);}else if(typeof(animate)=="function")
animate();},scrollBy:function(y){if(!this.enabled)
return false;this.slider.setValueBy(y/this.getCurrentMaximumDelta());}});Object.Event.extend(Control.ScrollBar);