(function(window){var document=window.document,navigator=window.navigator,msPointerEnabled=navigator.msPointerEnabled,TOUCH_EVENTS={start:msPointerEnabled?'MSPointerDown':'touchstart',move:msPointerEnabled?'MSPointerMove':'touchmove',end:msPointerEnabled?'MSPointerUp':'touchend'},dummyStyle=document.createElement('div').style,vendor=(function(){var vendors='t,webkitT,MozT,msT,OT'.split(','),t,i=0,l=vendors.length;for(;i<l;i++){t=vendors[i]+'ransform';if(t in dummyStyle){return vendors[i].substr(0,vendors[i].length-1);}}
return false;}()),prefixStyle=function(style){if(vendor==='')return style;style=style.charAt(0).toUpperCase()+style.substr(1);return vendor+style;},transition=prefixStyle('transition'),transitionEndEvent=(function(){if(vendor=='webkit'||vendor==='O'){return vendor.toLowerCase()+'TransitionEnd';}
return'transitionend';}()),listenTransition=function(target,duration,callbackFn){var me=this,clear=function(){if(target.transitionTimer)clearTimeout(target.transitionTimer);target.transitionTimer=null;target.removeEventListener(transitionEndEvent,handler,false);},handler=function(){clear();if(callbackFn)callbackFn.call(me);};clear();target.addEventListener(transitionEndEvent,handler,false);target.transitionTimer=setTimeout(handler,duration+100);};var DragLoader=function(el,options){this.ct=el?(typeof el==='string'?document.querySelector(el):el):document.body;options=options||{};this.options=options;if(typeof options.threshold==='undefined')options.threshold=80;if(typeof options.dragDownThreshold==='undefined')options.dragDownThreshold=options.threshold;if(typeof options.dragUpThreshold==='undefined')options.dragUpThreshold=options.threshold;this._events={};this._draggable=true;this.ct.addEventListener(TOUCH_EVENTS.start,this,false);};DragLoader.prototype={STATUS:{default:'default',prepare:'prepare',load:'load'},_createDragDownRegion:function(){this._removeDragDownRegion();this.header=document.createElement('div');this.header.style.cssText='position:relative;top:0;left:0;margin:0;padding:0;overflow:hidden;width:100%;height:0px;';this.header.className=this.options.dragDownRegionCls||'';this._touchCoords.status=this._processStatus('down',0,null,true);this.ct.insertBefore(this.header,this.ct.children[0]);return this.header;},_removeDragDownRegion:function(){if(this.header){this.ct.removeChild(this.header);this.header=null;}},_createDragUpRegion:function(){this._removeDragUpRegion();this.footer=document.createElement('div');this.footer.style.cssText='position:relative;bottom:0;left:0;margin:0;padding:0;overflow:hidden;width:100%;height:0px;';this.footer.className=this.options.dragUpRegionCls||'';this._touchCoords.status=this._processStatus('up',0,null,true);this.ct.appendChild(this.footer);return this.footer;},_removeDragUpRegion:function(){if(this.footer){this.ct.removeChild(this.footer);this.footer=null;}},_processDragDownHelper:function(status){var options=this.options,helper=options.dragDownHelper;if(!options.preventDragHelper&&helper){this.header.innerHTML=helper.call(this,status);}},_processDragUpHelper:function(status){var options=this.options,helper=options.dragUpHelper;if(!options.preventDragHelper&&helper){this.footer.innerHTML=helper.call(this,status);}},_processStatus:function(orient,offsetY,currentStatus,moved){var options=this.options,STATUS=this.STATUS,overflow,nextStatus=currentStatus,upperStr;if(orient){upperStr=orient.charAt(0).toUpperCase()+orient.substr(1);overflow=offsetY>options['drag'+upperStr+'Threshold'];if(!overflow&&currentStatus!=STATUS.default){this['_processDrag'+upperStr+'Helper'].call(this,STATUS.default);this._fireEvent('drag'+upperStr+'Default');nextStatus=STATUS.default;}else if(moved&&overflow&&currentStatus!=STATUS.prepare){this['_processDrag'+upperStr+'Helper'].call(this,STATUS.prepare);this._fireEvent('drag'+upperStr+'Prepare');nextStatus=STATUS.prepare;}else if(!moved&&overflow&&currentStatus!=STATUS.load){this['_processDrag'+upperStr+'Helper'].call(this,STATUS.load);this._fireEvent('drag'+upperStr+'Load');nextStatus=STATUS.load;}}
return nextStatus;},_onTouchStrat:function(e){this.ct.removeEventListener(TOUCH_EVENTS.move,this,false);this.ct.removeEventListener(TOUCH_EVENTS.end,this,false);var body=document.body,startScrollY=this.ct===body?(window.pageYOffset||window.scrollY||document.documentElement.scrollTop):this.ct.scrollTop;if(this._draggable&&(this.options.disableDragDown!==true||this.options.disableDragUp!==true)&&this._fireEvent('beforeDrag')!==false){this._draggable=false;this.ct.addEventListener(TOUCH_EVENTS.move,this,false);this.ct.addEventListener(TOUCH_EVENTS.end,this,false);this._touchCoords={};this._touchCoords.startY=msPointerEnabled?e.screenY:e.touches[0].screenY;this._touchCoords.startScrollY=startScrollY;}},_onTouchMove:function(e){var ct=this.ct,header=this.header,footer=this.footer,options=this.options,innerHeight=window.innerHeight,ctHeight=ct.scrollHeight,coords=this._touchCoords,startScrollY=coords.startScrollY,blockY=coords.blockY,startY=coords.startY,stopY=msPointerEnabled?e.screenY:e.touches[0].screenY,offsetY,overY;if(typeof coords.canDragDown==='undefined'){coords.canDragDown=options.disableDragDown!==true&&startY<stopY&&startScrollY<=0;}
if(typeof coords.canDragUp==='undefined'){coords.canDragUp=options.disableDragUp!==true&&startY>stopY&&startScrollY+innerHeight>=ctHeight;}
if(coords.canDragDown&&coords.dragUp!==true&&(coords.dragDown||startY-stopY+startScrollY<0)){e.preventDefault();coords.dragDown=true;if(!header){header=this._createDragDownRegion();}
if(typeof blockY==='undefined'){coords.blockY=blockY=stopY;}
offsetY=stopY-blockY;offsetY=offsetY>0?offsetY:0;overY=offsetY-options.dragDownThreshold;if(overY>100){offsetY=options.dragDownThreshold+75+(overY-100)*0.25;}else if(overY>50){offsetY=options.dragDownThreshold+50+(overY-50)*0.5;}
header.style.height=offsetY+'px';coords.status=this._processStatus('down',offsetY,coords.status,true);}else if(coords.canDragUp&&coords.dragDown!==true&&(coords.dragUp||startY-stopY+startScrollY+innerHeight>ctHeight)){e.preventDefault();coords.dragUp=true;if(!footer){footer=this._createDragUpRegion();}
if(typeof blockY==='undefined'){coords.blockY=blockY=stopY;}
offsetY=blockY-stopY;offsetY=offsetY>0?offsetY:0;overY=offsetY-options.dragUpThreshold;if(overY>100){offsetY=options.dragUpThreshold+75+(overY-100)*0.2;}else if(overY>50){offsetY=options.dragUpThreshold+50+(overY-50)*0.5;}
ct.scrollTop=startScrollY+offsetY;footer.style.height=offsetY+'px';coords.status=this._processStatus('up',offsetY,coords.status,true);}else{coords.blockY=stopY;}},_onTouchEnd:function(e){this.ct.removeEventListener(TOUCH_EVENTS.move,this,false);this.ct.removeEventListener(TOUCH_EVENTS.end,this,false);this._translate();},_translate:function(){var me=this,options=me.options,coords=me._touchCoords,orient,target,targetHeight,adjustHeight,maxDuration=200,duration,upperStr,threshold,endFn=function(){coords.status=me._processStatus(orient,targetHeight,coords.status,false);if(!orient||coords.status!==me.STATUS.load){me._removeDragDownRegion();me._removeDragUpRegion();me._touchCoords=null;me._draggable=true;}else if(orient=='down'){me._removeDragUpRegion();}else if(orient=='up'){me._removeDragDownRegion();}};if(!coords)return;orient=coords.dragDown?'down':(coords.dragUp?'up':null);if(orient){target=orient=='down'?me.header:me.footer;targetHeight=target.offsetHeight;upperStr=orient.charAt(0).toUpperCase()+orient.substr(1);threshold=options['drag'+upperStr+'Threshold'];adjustHeight=(!options.preventDragHelper&&targetHeight>threshold)?threshold:0;duration=Math.ceil((targetHeight-adjustHeight)/threshold*maxDuration);duration=duration>maxDuration?maxDuration:duration;listenTransition(target,duration,endFn);target.style[transition]='height '+duration+'ms';setTimeout(function(){target.style.height=adjustHeight+'px';},0);}else{endFn();}},reset:function(){this._translate();},on:function(type,fn){if(!this._events[type]){this._events[type]=[];}
this._events[type].push(fn);},off:function(type,fn){if(this._events[type]){this._events[type].every(function(cb,i){if(cb===fn){this._events[type].splice(i,1);return false;}});}},_fireEvent:function(type,args){var me=this,ret;if(me._events[type]){me._events[type].forEach(function(fn){ret=fn.apply(me,args||[]);});}
return ret;},setDragDownDisabled:function(disabled){this.options.disableDragDown=disabled;},setDragUpDisabled:function(disabled){this.options.disableDragUp=disabled;},handleEvent:function(e){switch(e.type){case TOUCH_EVENTS.start:this._onTouchStrat(e);break;case TOUCH_EVENTS.move:this._onTouchMove(e);break;case TOUCH_EVENTS.end:this._onTouchEnd(e);break;}},destroy:function(){if(!this.destroyed){this.destroyed=true;this._removeDragDownRegion();this._removeDragUpRegion();this.ct.removeEventListener(TOUCH_EVENTS.start,this,false);this.ct.removeEventListener(TOUCH_EVENTS.move,this,false);this.ct.removeEventListener(TOUCH_EVENTS.end,this,false);this.ct=null;}}};dummyStyle=null;window.DragLoader=DragLoader;})(window);