PhotoSwipe-一个好用的图片放大缩小插件

通过GitHub 下载PhotoSwipe https://github.com/dimsemenov/PhotoSwipe 相关的库

<link rel="stylesheet" href="css/photoswipe.css" />
<link rel="stylesheet" href="css/default-skin/default-skin.css" /> 

<script src="js/photoswipe.min.js"></script>
<script src="js/photoswipe-ui-default.js"></script>
<script src="js/connect.js"></script>
//引入相关的css和js文件及皮肤

connect.js

 document.writeln("<!-- Root element of PhotoSwipe. Must have class pswp. -->");
 document.writeln("<div class=\"pswp\" tabindex=\"-1\" role=\"dialog\" aria-hidden=\"true\">");
 document.writeln("");
 document.writeln("    <!-- Background of PhotoSwipe.");
 document.writeln("         It\'s a separate element as animating opacity is faster than rgba(). -->");
 document.writeln("    <div class=\"pswp__bg\"><\/div>");
 document.writeln("");
 document.writeln("    <!-- Slides wrapper with overflow:hidden. -->");
 document.writeln("    <div class=\"pswp__scroll-wrap\">");
 document.writeln("");
 document.writeln("        <!-- Container that holds slides.");
 document.writeln("            PhotoSwipe keeps only 3 of them in the DOM to save memory.");
 document.writeln("            Don\'t modify these 3 pswp__item elements, data is added later on. -->");
 document.writeln("        <div class=\"pswp__container\">");
 document.writeln("            <div class=\"pswp__item\"><\/div>");
 document.writeln("            <div class=\"pswp__item\"><\/div>");
 document.writeln("            <div class=\"pswp__item\"><\/div>");
 document.writeln("        <\/div>");
 document.writeln("");
 document.writeln("        <!-- Default (PhotoSwipeUI_Default) interface on top of sliding area. Can be changed. -->");
 document.writeln("        <div class=\"pswp__ui pswp__ui--hidden\">");
 document.writeln("");
 document.writeln("            <div class=\"pswp__top-bar\">");
 document.writeln("");
 document.writeln("                <!--  Controls are self-explanatory. Order can be changed. -->");
 document.writeln("");
 document.writeln("                <div class=\"pswp__counter\"><\/div>");
 document.writeln("");
 document.writeln("                <button class=\"pswp__button pswp__button--close\" title=\"Close (Esc)\"><\/button>");
 document.writeln("");
 document.writeln("");
 document.writeln("                <button class=\"pswp__button pswp__button--fs\" title=\"Toggle fullscreen\"><\/button>");
 document.writeln("");
 document.writeln("                <button class=\"pswp__button pswp__button--zoom\" title=\"Zoom in\/out\"><\/button>");
 document.writeln("");
 document.writeln("                <!-- Preloader demo http:\/\/codepen.io\/dimsemenov\/pen\/yyBWoR -->");
 document.writeln("                <!-- element will get class pswp__preloader--active when preloader is running -->");
 document.writeln("                <div class=\"pswp__preloader\">");
 document.writeln("                    <div class=\"pswp__preloader__icn\">");
 document.writeln("                        <div class=\"pswp__preloader__cut\">");
 document.writeln("                            <div class=\"pswp__preloader__donut\"><\/div>");
 document.writeln("                        <\/div>");
 document.writeln("                    <\/div>");
 document.writeln("                <\/div>");
 document.writeln("            <\/div>");
 document.writeln("");
 document.writeln("            <div class=\"pswp__share-modal pswp__share-modal--hidden pswp__single-tap\">");
 document.writeln("                <div class=\"pswp__share-tooltip\"><\/div>");
 document.writeln("            <\/div>");
 document.writeln("");
 document.writeln("            <button class=\"pswp__button pswp__button--arrow--left\" title=\"Previous (arrow left)\">");
 document.writeln("            <\/button>");
 document.writeln("");
 document.writeln("            <button class=\"pswp__button pswp__button--arrow--right\" title=\"Next (arrow right)\">");
 document.writeln("            <\/button>");
 document.writeln("");
 document.writeln("            <div class=\"pswp__caption\">");
 document.writeln("                <div class=\"pswp__caption__center\"><\/div>");
 document.writeln("            <\/div>");
 document.writeln("");
 document.writeln("        <\/div>");
 document.writeln("");
 document.writeln("    <\/div>");
 document.writeln("");
 document.writeln("<\/div>");
 //因为作者没有把相关的div放进js里，所以这边通过打印，具体可以观看官方文档得知为什么要这么做。
     (function() {

     var initPhotoSwipeFromDOM = function(gallerySelector) {

             var parseThumbnailElements = function(el) {
                 var thumbElements = el.childNodes,
                     numNodes = thumbElements.length,
                     items = [],
                     el,
                     childElements,
                     thumbnailEl,
                     size,
                     item;

                 for(var i = ; i < numNodes; i++) {
                     el = thumbElements[i];

                     // include only element nodes
                     if(el.nodeType !== ) {
                       continue;
                     }

                     childElements = el.children;

                     size = el.getAttribute('data-size').split('x');

                     // create slide object
                     item = {
                         src: el.getAttribute('href'),
                         w: parseInt(size[], ),
                         h: parseInt(size[], ),
                         author: el.getAttribute('data-author')
                     };

                     item.el = el; // save link to element for getThumbBoundsFn

                     if(childElements.length > ) {
                       item.msrc = childElements[].getAttribute('src'); // thumbnail url
                       if(childElements.length > ) {
                           item.title = childElements[].innerHTML; // caption (contents of figure)
                       }
                     }

                     var mediumSrc = el.getAttribute('data-med');
                       if(mediumSrc) {
                         size = el.getAttribute('data-med-size').split('x');
                         // "medium-sized" image
                         item.m = {
                               src: mediumSrc,
                               w: parseInt(size[], ),
                               h: parseInt(size[], )
                         };
                       }
                       // original image
                       item.o = {
                           src: item.src,
                           w: item.w,
                           h: item.h
                       };

                     items.push(item);
                 }

                 return items;
             };

             // find nearest parent element
             var closest = function closest(el, fn) {
                 return el && ( fn(el) ? el : closest(el.parentNode, fn) );
             };

             var onThumbnailsClick = function(e) {
                 e = e || window.event;
                 e.preventDefault ? e.preventDefault() : e.returnValue = false;

                 var eTarget = e.target || e.srcElement;

                 var clickedListItem = closest(eTarget, function(el) {
                     return el.tagName === 'A';
                 });

                 if(!clickedListItem) {
                     return;
                 }

                 var clickedGallery = clickedListItem.parentNode;

                 var childNodes = clickedListItem.parentNode.childNodes,
                     numChildNodes = childNodes.length,
                     nodeIndex = ,
                     index;

                 for (var i = ; i < numChildNodes; i++) {
                     if(childNodes[i].nodeType !== ) {
                         continue;
                     }

                     if(childNodes[i] === clickedListItem) {
                         index = nodeIndex;
                         break;
                     }
                     nodeIndex++;
                 }

                 if(index >= ) {
                     openPhotoSwipe( index, clickedGallery );
                 }
                 return false;
             };

             var photoswipeParseHash = function() {
                 var hash = window.location.hash.substring(),
                 params = {};

                 if(hash.length < ) { // pid=1
                     return params;
                 }

                 var vars = hash.split('&');
                 for (var i = ; i < vars.length; i++) {
                     if(!vars[i]) {
                         continue;
                     }
                     var pair = vars[i].split('=');
                     if(pair.length < ) {
                         continue;
                     }
                     params[pair[]] = pair[];
                 }

                 if(params.gid) {
                     params.gid = parseInt(params.gid, );
                 }

                 return params;
             };

             var openPhotoSwipe = function(index, galleryElement, disableAnimation, fromURL) {
                 var pswpElement = document.querySelectorAll('.pswp')[],
                     gallery,
                     options,
                     items;

                 items = parseThumbnailElements(galleryElement);

                 // define options (if needed)
                 options = {

                     galleryUID: galleryElement.getAttribute('data-pswp-uid'),

                     getThumbBoundsFn: function(index) {
                         // See Options->getThumbBoundsFn section of docs for more info
                         var thumbnail = items[index].el.children[],
                             pageYScroll = window.pageYOffset || document.documentElement.scrollTop,
                             rect = thumbnail.getBoundingClientRect(); 

                         return {x:rect.left, y:rect.top + pageYScroll, w:rect.width};
                     },

                     addCaptionHTMLFn: function(item, captionEl, isFake) {
                         if(!item.title) {
                             captionEl.children[].innerText = '';
                             return false;
                         }
                         captionEl.children[].innerHTML = item.title +  '<br/><small>Photo: ' + item.author + '</small>';
                         return true;
                     }

                 };

                 if(fromURL) {
                     if(options.galleryPIDs) {
                         // parse real index when custom PIDs are used
                         // http://photoswipe.com/documentation/faq.html#custom-pid-in-url
                         for(var j = ; j < items.length; j++) {
                             if(items[j].pid == index) {
                                 options.index = j;
                                 break;
                             }
                         }
                     } else {
                         options.index = parseInt(index, ) - ;
                     }
                 } else {
                     options.index = parseInt(index, );
                 }

                 // exit if index not found
                 if( isNaN(options.index) ) {
                     return;
                 }

                 var radios = document.getElementsByName('gallery-style');
                 for (var i = , length = radios.length; i < length; i++) {
                     if (radios[i].checked) {
                         if(radios[i].id == 'radio-all-controls') {

                         } else if(radios[i].id == 'radio-minimal-black') {
                             options.mainClass = 'pswp--minimal--dark';
                             options.barsSize = {top:,bottom:};
                             options.captionEl = false;
                             options.fullscreenEl = false;
                             options.shareEl = false;
                             options.bgOpacity = 0.85;
                             options.tapToClose = true;
                             options.tapToToggleControls = false;
                         }
                         break;
                     }
                 }

                 if(disableAnimation) {
                     options.showAnimationDuration = ;
                 }

                 // Pass data to PhotoSwipe and initialize it
                 gallery = new PhotoSwipe( pswpElement, PhotoSwipeUI_Default, items, options);

                 // see: http://photoswipe.com/documentation/responsive-images.html
                 var realViewportWidth,
                     useLargeImages = false,
                     firstResize = true,
                     imageSrcWillChange;

                 gallery.listen('beforeResize', function() {

                     var dpiRatio = window.devicePixelRatio ? window.devicePixelRatio : ;
                     dpiRatio = Math.min(dpiRatio, 2.5);
                     realViewportWidth = gallery.viewportSize.x * dpiRatio;

                     if(realViewportWidth >=  || (!gallery.likelyTouchDevice && realViewportWidth > ) || screen.width >  ) {
                         if(!useLargeImages) {
                             useLargeImages = true;
                             imageSrcWillChange = true;
                         }

                     } else {
                         if(useLargeImages) {
                             useLargeImages = false;
                             imageSrcWillChange = true;
                         }
                     }

                     if(imageSrcWillChange && !firstResize) {
                         gallery.invalidateCurrItems();
                     }

                     if(firstResize) {
                         firstResize = false;
                     }

                     imageSrcWillChange = false;

                 });

                 gallery.listen('gettingData', function(index, item) {
                     if( useLargeImages ) {
                         item.src = item.o.src;
                         item.w = item.o.w;
                         item.h = item.o.h;
                     } else {
                         item.src = item.m.src;
                         item.w = item.m.w;
                         item.h = item.m.h;
                     }
                 });

                 gallery.init();
             };

             // select all gallery elements
             var galleryElements = document.querySelectorAll( gallerySelector );
             for(var i = , l = galleryElements.length; i < l; i++) {
                 galleryElements[i].setAttribute('data-pswp-uid', i+);
                 galleryElements[i].onclick = onThumbnailsClick;
             }

             // Parse URL and open gallery if it contains #&pid=3&gid=1
             var hashData = photoswipeParseHash();
             if(hashData.pid && hashData.gid) {
                 openPhotoSwipe( hashData.pid,  galleryElements[ hashData.gid -  ], true, true );
             }
         };

         initPhotoSwipeFromDOM('.photoswipe');

     })();

我们通过名为photoswipe的class通知要用到的子元素。

a里的图片为放大之后的图片，img里的图片为可实际查看的小图，data-size为要放大的图片大小。

 <div class="photoswipe">
     <a href="img/1-max.jpeg" data-size='1000x1000' >
         <img src="img/1-450.jpeg"/>
     </a>
     <a href="http://img3.imgtn.bdimg.com/it/u=4166721891,1503444760&fm=26&gp=0.jpg" data-size='1000x1000' >
         <img src="http://img3.imgtn.bdimg.com/it/u=4166721891,1503444760&fm=26&gp=0.jpg"/>
     </a>
     <a href="http://www.91danji.com/attachments/201511/19/10/24kf5fidw.jpg" data-size='1000x1000' >
         <img src="http://www.91danji.com/attachments/201511/19/10/24kf5fidw.jpg"/>
     </a>
 </div>

拓展：因项目需要，以及通过后台渲染出的图片大小或外链的图片，总不可能一个个设置data-size，于是用jQuery配合js写了几段代码。

 $(document).ready(function(){ //如果认为代码写的很乱可以自行修改
     var pic=$("[data-size]");
     pic.each(function(){
     var _this = $(this);
     var images = new Image(); //实例化图片
     images.src = _this.find('img').attr('src');    //获取小图的链接 进行计算
     images.onload = function(){  //当图片加载完
     var tpW = images.width; //图片实际宽度
     var tpH = images.height //图片实际高度
     var winW = $(window).width(); //浏览器实际宽度
     var winH = $(window).height(); //浏览器实际高度
     var tpRatio = Math.min((winW/tpW),(winH/tpH));
     var getW = tpW * tpRatio;
     var getH = tpH * tpRatio; // 屏幕高度 * 图片宽度 / 图片高度
     _this.attr("data-size",parseInt(getW,)+"x"+parseInt(getH,));
     }
  });
 });

该插件是自适应的，具体可以通过谷歌浏览器查看该插件的炫酷之处。