/* This script acquires all image tags encased in anchor tags that link to an image file then adds onclick events to popup + zoom the image rather than visiting the given link. */
var img2popup = {
  popup: null,
  focused: false,
  Go: function(ele) {
    if (this.popup == null) this.doSetup();
    this.doParse();
  },
  doParse: function(ele) {
    var context = (typeof ele === 'undefined' ? document.getElementsByTagName("img") : ele.getElementsByTagName("img"));
    for (var i = 0; i < context.length; i++) {
      var p = context[i].parentNode;
      if (p.nodeName == "A") {
        if (p.href.match(/\.(png|jpg|jpeg)$/)) {
          p.onclick = (function(p) { return function(e) {
            if (!e) var e = window.event;
            e.cancelBubble = true; if (e.stopPropagation) e.stopPropagation();
            img2popup.popup.src = p.href;
            return false;
          }})(p);
        }
      }
    }
  },
  doSetup: function() {
    this.popup = document.createElement("img");
    this.popup.style.visibility = "hidden";
    this.popup.id = "popup";
    this.popup.onload = function() {
      img2popup.doResize();
      this.style.visibility = "visible";
      img2popup.focused = true;
    };
    document.body.appendChild(this.popup);
    document.onclick = function() {
      if (img2popup.focused) img2popup.doHide();
    };
    window.onresize = img2popup.doResize;
  },
  doHide: function() {
    this.popup.style.visibility = "hidden";
    this.popup.src = "";
    this.focused = false;
  },
  doResize: function() {
    this.popup.style.width = this.popup.style.height = '';
    var w = this.popup.width;
    var h = this.popup.height;
    var r = Math.min(((window.innerWidth || document.documentElement.clientWidth)-32) / w, ((window.innerHeight || document.documentElement.clientHeight)-32) / h);
    if (r < 1.0) {
      w *= r;
      h *= r;
    }
    this.popup.style.marginLeft = -(w/2)+"px";
    this.popup.style.marginTop = -(h/2)+"px";
    this.popup.style.width = w+"px";
    this.popup.style.height = h+"px";
  }
};