src/net/instaweb/genfiles/rewriter/lazyload_images_dbg.js

(function(){var pagespeedutils = {MAX_POST_SIZE:131072, sendBeacon:function(a, b, c) {
  var d;
  if (window.XMLHttpRequest) {
    d = new XMLHttpRequest;
  } else {
    if (window.ActiveXObject) {
      try {
        d = new ActiveXObject("Msxml2.XMLHTTP");
      } catch (f) {
        try {
          d = new ActiveXObject("Microsoft.XMLHTTP");
        } catch (g) {
        }
      }
    }
  }
  if (!d) {
    return !1;
  }
  var e = -1 == a.indexOf("?") ? "?" : "&";
  a = a + e + "url=" + encodeURIComponent(b);
  d.open("POST", a);
  d.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
  d.send(c);
  return !0;
}, addHandler:function(a, b, c) {
  if (a.addEventListener) {
    a.addEventListener(b, c, !1);
  } else {
    if (a.attachEvent) {
      a.attachEvent("on" + b, c);
    } else {
      var d = a["on" + b];
      a["on" + b] = function() {
        c.call(this);
        d && d.call(this);
      };
    }
  }
}, getPosition:function(a) {
  for (var b = a.offsetTop, c = a.offsetLeft;a.offsetParent;) {
    a = a.offsetParent, b += a.offsetTop, c += a.offsetLeft;
  }
  return {top:b, left:c};
}, getWindowSize:function() {
  return {height:window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight, width:window.innerWidth || document.documentElement.clientWidth || document.body.clientWidth};
}, inViewport:function(a, b) {
  var c = pagespeedutils.getPosition(a);
  return pagespeedutils.positionInViewport(c, b);
}, positionInViewport:function(a, b) {
  return a.top < b.height && a.left < b.width;
}, getRequestAnimationFrame:function() {
  return window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame || null;
}};
pagespeedutils.now = Date.now || function() {
  return +new Date;
};
window.pagespeed = window.pagespeed || {};
var pagespeed = window.pagespeed;
pagespeed.LazyloadImages = function(a) {
  this.deferred_ = [];
  this.buffer_ = 0;
  this.force_load_ = !1;
  this.blank_image_src_ = a;
  this.scroll_timer_ = null;
  this.last_scroll_time_ = 0;
  this.min_scroll_time_ = 200;
  this.onload_done_ = !1;
  this.imgs_to_load_before_beaconing_ = 0;
};
pagespeed.LazyloadImages.prototype.countDeferredImgs_ = function() {
  for (var a = 0, b = document.getElementsByTagName("img"), c = 0, d;d = b[c];c++) {
    -1 != d.src.indexOf(this.blank_image_src_) && this.hasAttribute_(d, "data-pagespeed-lazy-src") && a++;
  }
  return a;
};
pagespeed.LazyloadImages.prototype.viewport_ = function() {
  var a = 0;
  "number" == typeof window.pageYOffset ? a = window.pageYOffset : document.body && document.body.scrollTop ? a = document.body.scrollTop : document.documentElement && document.documentElement.scrollTop && (a = document.documentElement.scrollTop);
  var b = window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight;
  return {top:a, bottom:a + b, height:b};
};
pagespeed.LazyloadImages.prototype.compute_top_ = function(a) {
  var b = a.getAttribute("data-pagespeed-lazy-position");
  if (b) {
    return parseInt(b, 0);
  }
  var b = a.offsetTop, c = a.offsetParent;
  c && (b += this.compute_top_(c));
  b = Math.max(b, 0);
  a.setAttribute("data-pagespeed-lazy-position", b);
  return b;
};
pagespeed.LazyloadImages.prototype.offset_ = function(a) {
  var b = this.compute_top_(a);
  return {top:b, bottom:b + a.offsetHeight};
};
pagespeed.LazyloadImages.prototype.getStyle_ = function(a, b) {
  if (a.currentStyle) {
    return a.currentStyle[b];
  }
  if (document.defaultView && document.defaultView.getComputedStyle) {
    var c = document.defaultView.getComputedStyle(a, null);
    if (c) {
      return c.getPropertyValue(b);
    }
  }
  return a.style && a.style[b] ? a.style[b] : "";
};
pagespeed.LazyloadImages.prototype.isVisible_ = function(a) {
  if (!this.onload_done_ && (0 == a.offsetHeight || 0 == a.offsetWidth)) {
    return !1;
  }
  if ("relative" == this.getStyle_(a, "position")) {
    return !0;
  }
  var b = this.viewport_(), c = a.getBoundingClientRect();
  c ? (a = c.top - b.height, b = c.bottom) : (c = this.offset_(a), a = c.top - b.bottom, b = c.bottom - b.top);
  return a <= this.buffer_ && 0 <= b + this.buffer_;
};
pagespeed.LazyloadImages.prototype.loadIfVisibleAndMaybeBeacon = function(a) {
  this.overrideAttributeFunctionsInternal_(a);
  var b = this;
  window.setTimeout(function() {
    var c = a.getAttribute("data-pagespeed-lazy-src");
    if (c) {
      if ((b.force_load_ || b.isVisible_(a)) && -1 != a.src.indexOf(b.blank_image_src_)) {
        var d = a.parentNode, e = a.nextSibling;
        d && d.removeChild(a);
        a._getAttribute && (a.getAttribute = a._getAttribute);
        a.removeAttribute("onload");
        a.tagName && "IMG" == a.tagName && pagespeed.CriticalImages && pagespeedutils.addHandler(a, "load", function(a) {
          pagespeed.CriticalImages.checkImageForCriticality(this);
          b.onload_done_ && (b.imgs_to_load_before_beaconing_--, 0 == b.imgs_to_load_before_beaconing_ && pagespeed.CriticalImages.checkCriticalImages());
        });
        a.removeAttribute("data-pagespeed-lazy-src");
        a.removeAttribute("data-pagespeed-lazy-replaced-functions");
        d && d.insertBefore(a, e);
        if (d = a.getAttribute("data-pagespeed-lazy-srcset")) {
          a.srcset = d, a.removeAttribute("data-pagespeed-lazy-srcset");
        }
        a.src = c;
      } else {
        b.deferred_.push(a);
      }
    }
  }, 0);
};
pagespeed.LazyloadImages.prototype.loadIfVisibleAndMaybeBeacon = pagespeed.LazyloadImages.prototype.loadIfVisibleAndMaybeBeacon;
pagespeed.LazyloadImages.prototype.loadAllImages = function() {
  this.force_load_ = !0;
  this.loadVisible_();
};
pagespeed.LazyloadImages.prototype.loadAllImages = pagespeed.LazyloadImages.prototype.loadAllImages;
pagespeed.LazyloadImages.prototype.loadVisible_ = function() {
  var a = this.deferred_, b = a.length;
  this.deferred_ = [];
  for (var c = 0;c < b;++c) {
    this.loadIfVisibleAndMaybeBeacon(a[c]);
  }
};
pagespeed.LazyloadImages.prototype.hasAttribute_ = function(a, b) {
  return a.getAttribute_ ? null != a.getAttribute_(b) : null != a.getAttribute(b);
};
pagespeed.LazyloadImages.prototype.overrideAttributeFunctions = function() {
  for (var a = document.getElementsByTagName("img"), b = 0, c;c = a[b];b++) {
    this.hasAttribute_(c, "data-pagespeed-lazy-src") && this.overrideAttributeFunctionsInternal_(c);
  }
};
pagespeed.LazyloadImages.prototype.overrideAttributeFunctions = pagespeed.LazyloadImages.prototype.overrideAttributeFunctions;
pagespeed.LazyloadImages.prototype.overrideAttributeFunctionsInternal_ = function(a) {
  var b = this;
  this.hasAttribute_(a, "data-pagespeed-lazy-replaced-functions") || (a._getAttribute = a.getAttribute, a.getAttribute = function(a) {
    "src" == a.toLowerCase() && b.hasAttribute_(this, "data-pagespeed-lazy-src") && (a = "data-pagespeed-lazy-src");
    return this._getAttribute(a);
  }, a.setAttribute("data-pagespeed-lazy-replaced-functions", "1"));
};
pagespeed.lazyLoadInit = function(a, b) {
  var c = new pagespeed.LazyloadImages(b);
  pagespeed.lazyLoadImages = c;
  pagespeedutils.addHandler(window, "load", function() {
    c.onload_done_ = !0;
    c.force_load_ = a;
    c.buffer_ = 200;
    pagespeed.CriticalImages && (c.imgs_to_load_before_beaconing_ = c.countDeferredImgs_(), 0 == c.imgs_to_load_before_beaconing_ && pagespeed.CriticalImages.checkCriticalImages());
    c.loadVisible_();
  });
  0 != b.indexOf("data") && ((new Image).src = b);
  var d = function() {
    if (!(c.onload_done_ && a || c.scroll_timer_)) {
      var b = (new Date).getTime(), d = c.min_scroll_time_;
      b - c.last_scroll_time_ > c.min_scroll_time_ && (d = 0);
      c.scroll_timer_ = window.setTimeout(function() {
        c.last_scroll_time_ = (new Date).getTime();
        c.loadVisible_();
        c.scroll_timer_ = null;
      }, d);
    }
  };
  pagespeedutils.addHandler(window, "scroll", d);
  pagespeedutils.addHandler(window, "resize", d);
};
pagespeed.lazyLoadInit = pagespeed.lazyLoadInit;
})();