手机端点击图片放大特效PhotoSwipe.js插件实现

//根据需求自己添加的S
//判断是单击还是双击 单击关闭 双击放大
tap_num++;
if(tap_num < 2){
 setTimeout(function(){
  if(tap_num > 1){
   tap_num = 0;
   return;
  }else{
   tap_num = 0;
   //判断是否有拖拽 如有拖拽触发拖拽事件 没有则关闭
   if(_isDragging){
    return;
   }else{
    self.close();
   }
  }
 },200);
}
//根据需求自己添加的E

var tapTimer,
 tapReleasePoint = {},
 _dispatchTapEvent = function(origEvent, releasePoint, pointerType) {  
  var e = document.createEvent( 'CustomEvent' ),
   eDetail = {
    origEvent:origEvent, 
    target:origEvent.target, 
    releasePoint: releasePoint, 
    pointerType:pointerType || 'touch'
   };

  e.initCustomEvent( 'pswpTap', true, true, eDetail );
  origEvent.target.dispatchEvent(e);
 };
var tap_num = 0;

_registerModule('Tap', {
 publicMethods: {
  initTap: function() {
   _listen('firstTouchStart', self.onTapStart);
   _listen('touchRelease', self.onTapRelease);
   _listen('destroy', function() {
    tapReleasePoint = {};
    tapTimer = null;
   });
  },
  onTapStart: function(touchList) {
   if(touchList.length > 1) {
    clearTimeout(tapTimer);
    tapTimer = null;
   }

   //根据需求自己添加的S
   //判断是单击还是双击 单击关闭 双击放大
   tap_num++;
   if(tap_num < 2){
    setTimeout(function(){
     if(tap_num > 1){
      tap_num = 0;
      return;
     }else{
      tap_num = 0;
      //判断是否有拖拽 如有拖拽触发拖拽事件 没有则关闭
      if(_isDragging){
       return;
      }else{
       self.close();
      }
     }
    },200);
   }
   //根据需求自己添加的E
  },
  onTapRelease: function(e, releasePoint) {
   if(!releasePoint) {
    return;
   }

   if(!_moved && !_isMultitouch && !_numAnimations) {
    var p0 = releasePoint;
    if(tapTimer) {
     clearTimeout(tapTimer);
     tapTimer = null;

     // Check if taped on the same place
     if ( _isNearbyPoints(p0, tapReleasePoint) ) {
      _shout('doubleTap', p0);
      return;
     }
    }

    if(releasePoint.type === 'mouse') {
     _dispatchTapEvent(e, releasePoint, 'mouse');
     return;
    }

    var clickedTagName = e.target.tagName.toUpperCase();
    // avoid double tap delay on buttons and elements that have class pswp__single-tap
    if(clickedTagName === 'BUTTON' || framework.hasClass(e.target, 'pswp__single-tap') ) {
     _dispatchTapEvent(e, releasePoint);
     return;
    }

    _equalizePoints(tapReleasePoint, p0);

    tapTimer = setTimeout(function() {
     _dispatchTapEvent(e, releasePoint);
     tapTimer = null;
    }, 300);
   }
  }
 }
});

<div id="demo-test-gallery" class="demo-gallery">
 <a href="https://farm4.staticflickr.com/3894/15008518202_c265dfa55f_h.jpg" data-size="1600x1600" data-med="https://farm4.staticflickr.com/3894/15008518202_b016d7d289_b.jpg" data-med-size="1024x1024">
  <img src="https://farm4.staticflickr.com/3894/15008518202_b016d7d289_m.jpg" alt="" />
 </a>

 <a href="https://farm6.staticflickr.com/5591/15008867125_b61960af01_h.jpg" data-size="1600x1068" data-med="https://farm6.staticflickr.com/5591/15008867125_68a8ed88cc_b.jpg" data-med-size="1024x1024">
  <img src="https://farm6.staticflickr.com/5591/15008867125_68a8ed88cc_m.jpg" alt="" />
 </a>
</div>

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("    <button class=\"pswp__button pswp__button--share\" title=\"Share\"><\/button>");
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>");


(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 = 0; i < numNodes; i++) {
     el = thumbElements[i];

     // include only element nodes
     if(el.nodeType !== 1) {
      continue;
     }

     childElements = el.children;

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

     // create slide object
     item = {
      src: el.getAttribute('href'),
      w: parseInt(size[0], 10),
      h: parseInt(size[1], 10),
      author: el.getAttribute('data-author')
     };

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

     if(childElements.length > 0) {
      item.msrc = childElements[0].getAttribute('src'); // thumbnail url
      if(childElements.length > 1) {
       item.title = childElements[1].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[0], 10),
       h: parseInt(size[1], 10)
      };
     }
     // 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 = 0,
      index;

    for (var i = 0; i < numChildNodes; i++) {
     if(childNodes[i].nodeType !== 1) {
      continue;
     }

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

    if(index >= 0) {
     openPhotoSwipe( index, clickedGallery );
    }
    return false;
   };

   var photoswipeParseHash = function() {
    var hash = window.location.hash.substring(1),
      params = {};

    if(hash.length < 5) { // pid=1
     return params;
    }

    var vars = hash.split('&');
    for (var i = 0; i < vars.length; i++) {
     if(!vars[i]) {
      continue;
     }
     var pair = vars[i].split('=');
     if(pair.length < 2) {
      continue;
     }
     params[pair[0]] = pair[1];
    }

    if(params.gid) {
     params.gid = parseInt(params.gid, 10);
    }

    return params;
   };

   var openPhotoSwipe = function(index, galleryElement, disableAnimation, fromURL) {
    var pswpElement = document.querySelectorAll('.pswp')[0],
      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[0],
        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[0].innerText = '';
       return false;
      }
      captionEl.children[0].innerHTML = item.title + '<br/><small>Photo: ' + item.author + '</small>';
      return true;
     }

    };

    // options for control bar
    options.shareEl = false;
    options.fullscreenEl = false;

    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 = 0; j < items.length; j++) {
       if(items[j].pid == index) {
        options.index = j;
        break;
       }
      }
     } else {
      options.index = parseInt(index, 10) - 1;
     }
    } else {
     options.index = parseInt(index, 10);
    }

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



    // 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 : 1;
     dpiRatio = Math.min(dpiRatio, 2.5);
     realViewportWidth = gallery.viewportSize.x * dpiRatio;


     if(realViewportWidth >= 1200 || (!gallery.likelyTouchDevice && realViewportWidth > 800) || screen.width > 1200 ) {
      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 = 0, l = galleryElements.length; i < l; i++) {
    galleryElements[i].setAttribute('data-pswp-uid', i+1);
    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 - 1 ], true, true );
   }
  };

  initPhotoSwipeFromDOM('.demo-gallery');

 })();