var Drag=new Class({Implements:[Events,Options],options:{snap:6,unit:'px',grid:false,style:true,limit:false,handle:false,invert:false,preventDefault:false,modifiers:{x:'left',y:'top'}},initialize:function(){var params=Array.link(arguments,{'options':Object.type,'element':$defined});this.element=$(params.element);this.document=this.element.getDocument();this.setOptions(params.options||{});var htype=$type(this.options.handle);this.handles=(htype=='array'||htype=='collection')?$$(this.options.handle):$(this.options.handle)||this.element;this.mouse={'now':{},'pos':{}};this.value={'start':{},'now':{}};this.selection=(Browser.Engine.trident)?'selectstart':'mousedown';this.bound={start:this.start.bind(this),check:this.check.bind(this),drag:this.drag.bind(this),stop:this.stop.bind(this),cancel:this.cancel.bind(this),eventStop:$lambda(false)};this.attach();},attach:function(){this.handles.addEvent('mousedown',this.bound.start);return this;},detach:function(){this.handles.removeEvent('mousedown',this.bound.start);return this;},start:function(event){if(this.options.preventDefault)event.preventDefault();this.fireEvent('beforeStart',this.element);this.mouse.start=event.page;var limit=this.options.limit;this.limit={'x':[],'y':[]};for(var z in this.options.modifiers){if(!this.options.modifiers[z])continue;if(this.options.style)this.value.now[z]=this.element.getStyle(this.options.modifiers[z]).toInt();else this.value.now[z]=this.element[this.options.modifiers[z]];if(this.options.invert)this.value.now[z]*=-1;this.mouse.pos[z]=event.page[z]-this.value.now[z];if(limit&&limit[z]){for(var i=2;i--;i){if($chk(limit[z][i]))this.limit[z][i]=$lambda(limit[z][i])();}}}
if($type(this.options.grid)=='number')this.options.grid={'x':this.options.grid,'y':this.options.grid};this.document.addEvents({mousemove:this.bound.check,mouseup:this.bound.cancel});this.document.addEvent(this.selection,this.bound.eventStop);},check:function(event){if(this.options.preventDefault)event.preventDefault();var distance=Math.round(Math.sqrt(Math.pow(event.page.x-this.mouse.start.x,2)+Math.pow(event.page.y-this.mouse.start.y,2)));if(distance>this.options.snap){this.cancel();this.document.addEvents({mousemove:this.bound.drag,mouseup:this.bound.stop});this.fireEvent('start',this.element).fireEvent('snap',this.element);}},drag:function(event){if(this.options.preventDefault)event.preventDefault();this.mouse.now=event.page;for(var z in this.options.modifiers){if(!this.options.modifiers[z])continue;this.value.now[z]=this.mouse.now[z]-this.mouse.pos[z];if(this.options.invert)this.value.now[z]*=-1;if(this.options.limit&&this.limit[z]){if($chk(this.limit[z][1])&&(this.value.now[z]>this.limit[z][1])){this.value.now[z]=this.limit[z][1];}else if($chk(this.limit[z][0])&&(this.value.now[z]<this.limit[z][0])){this.value.now[z]=this.limit[z][0];}}
if(this.options.grid[z])this.value.now[z]-=(this.value.now[z]%this.options.grid[z]);if(this.options.style)this.element.setStyle(this.options.modifiers[z],this.value.now[z]+this.options.unit);else this.element[this.options.modifiers[z]]=this.value.now[z];}
this.fireEvent('drag',this.element);},cancel:function(event){this.document.removeEvent('mousemove',this.bound.check);this.document.removeEvent('mouseup',this.bound.cancel);if(event){this.document.removeEvent(this.selection,this.bound.eventStop);this.fireEvent('cancel',this.element);}},stop:function(event){this.document.removeEvent(this.selection,this.bound.eventStop);this.document.removeEvent('mousemove',this.bound.drag);this.document.removeEvent('mouseup',this.bound.stop);if(event)this.fireEvent('complete',this.element);}});Element.implement({makeResizable:function(options){return new Drag(this,$merge({modifiers:{'x':'width','y':'height'}},options));}});