var Slider=new Class({Implements:[Events,Options],options:{onTick:function(position){if(this.options.snap)position=this.toPosition(this.step);this.knob.setStyle(this.property,position);},snap:false,offset:0,range:false,wheel:false,steps:100,mode:'horizontal'},initialize:function(element,knob,options){this.setOptions(options);this.element=$(element);this.knob=$(knob);this.previousChange=this.previousEnd=this.step=-1;this.element.addEvent('mousedown',this.clickedElement.bind(this));if(this.options.wheel)this.element.addEvent('mousewheel',this.scrolledElement.bindWithEvent(this));var offset,limit={},modifiers={'x':false,'y':false};switch(this.options.mode){case'vertical':this.axis='y';this.property='top';offset='offsetHeight';break;case'horizontal':this.axis='x';this.property='left';offset='offsetWidth';}
this.half=this.knob[offset]/2;this.full=this.element[offset]-this.knob[offset]+(this.options.offset*2);this.min=$chk(this.options.range[0])?this.options.range[0]:0;this.max=$chk(this.options.range[1])?this.options.range[1]:this.options.steps;this.range=this.max-this.min;this.steps=this.options.steps||this.full;this.stepSize=Math.abs(this.range)/this.steps;this.stepWidth=this.stepSize*this.full/Math.abs(this.range);this.knob.setStyle('position','relative').setStyle(this.property,-this.options.offset);modifiers[this.axis]=this.property;limit[this.axis]=[-this.options.offset,this.full-this.options.offset];this.drag=new Drag(this.knob,{snap:0,limit:limit,modifiers:modifiers,onDrag:this.draggedKnob.bind(this),onStart:this.draggedKnob.bind(this),onComplete:function(){this.draggedKnob();this.end();}.bind(this)});if(this.options.snap){this.drag.options.grid=Math.ceil(this.stepWidth);this.drag.options.limit[this.axis][1]=this.full;}},set:function(step){if(!((this.range>0)^(step<this.min)))step=this.min;if(!((this.range>0)^(step>this.max)))step=this.max;this.step=Math.round(step);this.checkStep();this.end();this.fireEvent('tick',this.toPosition(this.step));return this;},clickedElement:function(event){var dir=this.range<0?-1:1;var position=event.page[this.axis]-this.element.getPosition()[this.axis]-this.half;position=position.limit(-this.options.offset,this.full-this.options.offset);this.step=Math.round(this.min+dir*this.toStep(position));this.checkStep();this.end();this.fireEvent('tick',position);},scrolledElement:function(event){var mode=(this.options.mode=='horizontal')?(event.wheel<0):(event.wheel>0);this.set(mode?this.step-this.stepSize:this.step+this.stepSize);event.stop();},draggedKnob:function(){var dir=this.range<0?-1:1;var position=this.drag.value.now[this.axis];position=position.limit(-this.options.offset,this.full-this.options.offset);this.step=Math.round(this.min+dir*this.toStep(position));this.checkStep();},checkStep:function(){if(this.previousChange!=this.step){this.previousChange=this.step;this.fireEvent('change',this.step);}},end:function(){if(this.previousEnd!==this.step){this.previousEnd=this.step;this.fireEvent('complete',this.step+'');}},toStep:function(position){var step=(position+this.options.offset)*this.stepSize/this.full*this.steps;return this.options.steps?Math.round(step-=step%this.stepSize):step;},toPosition:function(step){return(this.full*Math.abs(this.min-step))/(this.steps*this.stepSize)-this.options.offset;}});