libjs-img.srcset 2.0.0~20131003~dfsg-2 / usr / share / javascript / img.srcset / img.srcset.min.js

(function(win){"use strict";var _viewport=win.document.documentElement,_srcsetID=0,_srcsets=[],_eventPrefix="",_addEvent=win.addEventListener||(_eventPrefix="on")&&win.attachEvent,_removeEvent=win.removeEventListener||win.detachEvent,_srcExpr=/[^\s]+/g,_digitExpr=/[0-9\.]+/g,_timer=0,_matches=function(srcset){var srcList=srcset.indexOf(",")!==-1&&srcset.split(",")||[srcset],srcIndex=srcList.length-1,srcLength=srcIndex,list=null,listIndex=0,src="",media="";if(srcIndex<0){return}do{var list=srcList[srcLength-srcIndex].match(_srcExpr)||[],listIndex=list.length;while(listIndex--){var item=list[listIndex],feature=0,digits=0;if(listIndex>0){feature=item.indexOf("w")!==-1&&(win.innerWidth||_viewport.clientWidth)||item.indexOf("h")!==-1&&(win.innerHeight||_viewport.clientHeight)||item.indexOf("x")!==-1&&(win.devicePixelRatio||1);digits=Number(item.match(_digitExpr));if(feature&&digits&&digits>feature){break}}else{src=item;media=srcList[srcIndex]}}}while(srcIndex--);return src&&media&&{src:src,media:media}||false},_watch=function(evt){clearTimeout(_timer);_timer=setTimeout(function(){var srcset=null,srcsetIndex=_srcsetID-1,srcsetLength=srcsetIndex,match=false;do{srcset=_srcsets[srcsetLength-srcsetIndex];if(!srcset.element.parentNode){_srcsetID--;srcset.splice(srcsetIndex,1);continue}match=_matches(srcset.media);if(match&&srcset.matches!==match.media){srcset.matches=match.media;srcset.element.src=match.src}else if(!match){srcset.matches=false;srcset.src&&(srcset.element.src=srcset.src)}}while(srcsetIndex--)},10)},_init=function(){_removeEvent(_eventPrefix+"load",_init);win.Imgsrcset.parse();_watch();_addEvent(_eventPrefix+"resize",_watch);_addEvent(_eventPrefix+"orientationchange",_watch)};win.Imgsrcset={parse:function(){_srcsets=[];var imgs=win.document.getElementsByTagName("img")||[],imgIndex=imgs.length-1,imgLength=imgIndex,img=null,srcset="";do{img=imgs[imgLength-imgIndex];srcset=img.getAttribute("srcset")||"";if(!srcset){continue}_srcsetID=_srcsets.push({element:img,media:srcset,matches:false,src:img.getAttribute("src")||""})}while(imgIndex--)}};_addEvent(_eventPrefix+"load",_init)})(window);