var ScrollBox=Class.create();ScrollBox.NO_ACTION=0;ScrollBox.PAGE_ACTION=1;ScrollBox.JUMP_ACTION=2;Object.extend(ScrollBox.prototype,{initialize:function(element,css,options){this.element=element;Element.addClassName(this.element,'scrollbox'+css);this.opts={scroll_increment:30,hold_delay:500,hold_interval:100,drag_interval:100,update_check_interval:100,auto_hide:false,bar_action:ScrollBox.PAGE_ACTION};Object.extend(this.opts,options);this.content_div=document.createElement('div');Element.addClassName(this.content_div,'scrollbox_content'+css);$A(this.element.childNodes).each(function(n){this.content_div.appendChild(n);}.bind(this));this.element.appendChild(this.content_div);this.content_div.style.overflow='hidden';this.content_div.style.height='100%';this.scrollbar=document.createElement('div');Element.addClassName(this.scrollbar,'scrollbox_scrollbar'+css);this.element.appendChild(this.scrollbar);this.scrollbar.style.position='absolute';this.scrollbar.style.top='0';this.scrollbar.style.right='0';this.up_button=document.createElement('div');Element.addClassName(this.up_button,'scrollbox_up_button'+css);this.up_button.style.position='absolute';this.up_button.style.width='100%';this.up_button.style.top='0';this.up_button.style.right='0';this.scrollbar.appendChild(this.up_button);this.down_button=document.createElement('div');Element.addClassName(this.down_button,'scrollbox_down_button'+css);this.down_button.style.position='absolute';this.down_button.style.width='100%';this.down_button.style.bottom='0';this.down_button.style.right='0';this.scrollbar.appendChild(this.down_button);this.handle=document.createElement('div');Element.addClassName(this.handle,'scrollbox_handle'+css);this.handle.style.position='absolute';this.handle.style.width='100%';this.handle.style.right='0';this.scrollbar.appendChild(this.handle);this.scroll_pos=0;this.setSizes();Event.observe(this.up_button,'mousedown',function(e){this.buttonDown(e,this.scrollUp.bind(this));}.bindAsEventListener(this));Event.observe(this.down_button,'mousedown',function(e){this.buttonDown(e,this.scrollDown.bind(this));}.bindAsEventListener(this));Event.observe(document,'mouseup',this.buttonUp.bindAsEventListener(this));Event.observe(document,'mousemove',this.setMousePos.bindAsEventListener(this));Event.observe(this.handle,'mousedown',this.handleDown.bindAsEventListener(this));this.handle_update_interval=setInterval(this.updateCheck.bind(this),this.opts.update_check_interval);Event.observe(this.up_button,'click',function(e){Event.stop(e);}.bindAsEventListener(this));Event.observe(this.down_button,'click',function(e){Event.stop(e);}.bindAsEventListener(this));Event.observe(this.handle,'click',function(e){Event.stop(e);}.bindAsEventListener(this));Event.observe(this.scrollbar,'click',this.scrollBarClick.bindAsEventListener(this));this.keyboard_events=[[document,'keypress',this.keyboardEvent.bindAsEventListener(this)]];Event.observe(this.element,'click',this.enableKeyboardEvents.bindAsEventListener(this));Event.observe(document,'click',this.disableKeyboardEvents.bindAsEventListener(this));Event.observe(this.content_div,'mousewheel',this.scrollWheel.bindAsEventListener(this),true);Event.observe(this.content_div,'DOMMouseScroll',this.scrollWheel.bindAsEventListener(this),true);},scrollDown:function(){if(this.scroll_pos<this.scroll_max){this.scrollTo(this.scroll_pos+this.opts.scroll_increment<this.scroll_max?this.scroll_pos+this.opts.scroll_increment:this.scroll_max);return true;}
else{return false;}},scrollUp:function(){if(this.scroll_pos>0){this.scrollTo(this.scroll_pos>this.opts.scroll_increment?this.scroll_pos-this.opts.scroll_increment:0);return true;}
else{return false;}},scrollTo:function(new_pos){if(new_pos<0){new_pos=0;}
if(new_pos>this.scroll_max){new_pos=this.scroll_max;}
this.content_div.scrollTop=new_pos;this.scroll_pos=new_pos;this.updateHandle();},buttonDown:function(event,action){action();this.timeout=setTimeout(function(){action();this.timeout=null;if(this.interval){clearInterval(this.interval);}
this.interval=setInterval(action,this.opts.hold_interval);}.bind(this),this.opts.hold_delay);Event.stop(event);},buttonUp:function(event){if(this.timeout){clearTimeout(this.timeout);}
if(this.interval){clearInterval(this.interval);}
this.timeout=null;this.interval=null;this.down_position=null;},updateHandle:function(){if(this.scroll_max){this.handle_height=Math.floor(this.bar_height/this.scroll_height_ratio);}
else{this.handle_height=this.bar_height;}
if(this.opts.auto_hide){if(this.handle_height==this.bar_height){this.scrollbar.style.visibility='hidden';}
else{this.scrollbar.style.visibility='';}}
var handle_top=this.up_button.offsetHeight;var handle_bottom=this.up_button.offsetHeight+(this.bar_height-this.handle_height);var bar_dist_height=handle_bottom-handle_top;if(this.scroll_max)
this.handle_pos=handle_top+Math.floor(bar_dist_height*(this.scroll_pos/this.scroll_max));else
this.handle_pos=handle_top;this.handle.style.height=this.handle_height+'px';this.handle.style.top=this.handle_pos+'px';},handleDown:function(){this.down_position=this.raw_mouse_pos-Position.cumulativeOffset(this.handle)[1];if(this.interval){clearInterval(this.interval);}
this.interval=setInterval(function(){this.scrollTo(this.mouse_pos-(this.down_position*this.scroll_height_ratio));}.bindAsEventListener(this),this.opts.drag_interval);},setMousePos:function(e){if(document.all){tempY=event.clientY+document.body.scrollTop;}else{tempY=e.pageY;}
if(tempY<0){tempY=0;}
this.raw_mouse_pos=tempY;this.mouse_pos=Math.floor((tempY-this.scrollbar_top)*this.scroll_height_ratio);},setSizes:function(){this.scroll_max=this.content_div.scrollHeight-this.content_div.offsetHeight;if(this.scroll_max<0)this.scroll_max=0;if(this.scroll_pos>this.scroll_max){this.scrollTo(this.scroll_max);}
this.bar_height=this.scrollbar.offsetHeight-(this.up_button.offsetHeight+this.down_button.offsetHeight);if(!this.bar_height){setTimeout(this.setSizes.bind(this),100);}
this.scroll_height_ratio=(this.content_div.scrollHeight/this.bar_height);this.scroll_height_ratio=this.scroll_height_ratio>=1?this.scroll_height_ratio:1;this.scrollbar_top=Position.cumulativeOffset(this.scrollbar)[1]+this.up_button.offsetHeight;this.scrollbar_bottom=this.scrollbar_top+this.bar_height;this.updateHandle();},scrollBarClick:function(event){switch(this.opts.bar_action){case ScrollBox.PAGE_ACTION:if(this.mouse_pos<this.handle_pos*this.scroll_height_ratio){this.pageUp();}
else{this.pageDown();}
break;case ScrollBox.JUMP_ACTION:this.scrollTo(this.mouse_pos);break;}},pageUp:function(){this.scrollTo(this.scroll_pos-this.content_div.offsetHeight);},pageDown:function(){this.scrollTo(this.scroll_pos+this.content_div.offsetHeight);},scrollWheel:function(event){var scroll_amount=Event.wheel(event);if(scroll_amount>0){for(var i=0;i<Math.ceil(scroll_amount);++i){this.scrollUp();}
if(this.scroll_pos>0){Event.stop(event);}}
else if(scroll_amount<0){for(var i=0;i>Math.floor(scroll_amount);--i){this.scrollDown();}
if(this.scroll_pos<this.scroll_max){Event.stop(event);}}},updateCheck:function(){if(this.content_div.scrollTop!=this.scroll_pos){this.scrollTo(this.content_div.scrollTop);}
if(this.scroll_max!=this.content_div.scrollHeight-this.content_div.offsetHeight){this.setSizes();}},enableKeyboardEvents:function(event){this.disableKeyboardEvents(event);this.keyboard_events.each(function(ke){Event.observe(ke[0],ke[1],ke[2]);});this.within_enable_event=true;},disableKeyboardEvents:function(event){if(!this.within_enable_event){this.keyboard_events.each(function(ke){Event.stopObserving(ke[0],ke[1],ke[2]);});}
else{this.within_enable_event=false;}},keyboardEvent:function(event){switch(event.keyCode){case Event.KEY_HOME:this.scrollTo(0);break;case Event.KEY_END:this.scrollTo(this.scroll_max);break;case Event.KEY_PAGEUP:this.pageUp();break;case Event.KEY_PAGEDOWN:this.pageDown();break;case Event.KEY_UP:this.scrollUp();break;case Event.KEY_DOWN:this.scrollDown();break;default:return;}
Event.stop(event);}});Object.extend(Event,{wheel:function(event){var delta=0;if(!event)event=window.event;if(event.wheelDelta){delta=event.wheelDelta/120;if(window.opera)delta=-delta;}else if(event.detail){delta=-event.detail/3;}
return delta;}});