text: // Copyright 2012 The Go Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style
  // license that can be found in the LICENSE file.
  
  var PERMANENT_URL_PREFIX = '/static/';
  
  var SLIDE_CLASSES = ['far-past', 'past', 'current', 'next', 'far-next'];
  
  var PM_TOUCH_SENSITIVITY = 15;
  
  var curSlide;
  
  /* ---------------------------------------------------------------------- */
  /* classList polyfill by Eli Grey
   * (http://purl.eligrey.com/github/classList.js/blob/master/classList.js) */
  
  if (typeof document !== "undefined" && !("classList" in document.createElement("a"))) {
  
  (function (view) {
  
  var
      classListProp = "classList"
    , protoProp = "prototype"
    , elemCtrProto = (view.HTMLElement || view.Element)[protoProp]
    , objCtr = Object
      strTrim = String[protoProp].trim || function () {
      return this.replace(/^\s+|\s+$/g, "");
    }
    , arrIndexOf = Array[protoProp].indexOf || function (item) {
      for (var i = 0, len = this.length; i < len; i++) {
        if (i in this && this[i] === item) {
          return i;
        }
      }
      return -1;
    }
    // Vendors: please allow content code to instantiate DOMExceptions
    , DOMEx = function (type, message) {
      this.name = type;
      this.code = DOMException[type];
      this.message = message;
    }
    , checkTokenAndGetIndex = function (classList, token) {
      if (token === "") {
        throw new DOMEx(
            "SYNTAX_ERR"
          , "An invalid or illegal string was specified"
        );
      }
      if (/\s/.test(token)) {
        throw new DOMEx(
            "INVALID_CHARACTER_ERR"
          , "String contains an invalid character"
        );
      }
      return arrIndexOf.call(classList, token);
    }
    , ClassList = function (elem) {
      var
          trimmedClasses = strTrim.call(elem.className)
        , classes = trimmedClasses ? trimmedClasses.split(/\s+/) : []
      ;
      for (var i = 0, len = classes.length; i < len; i++) {
        this.push(classes[i]);
      }
      this._updateClassName = function () {
        elem.className = this.toString();
      };
    }
    , classListProto = ClassList[protoProp] = []
    , classListGetter = function () {
      return new ClassList(this);
    }
  ;
  // Most DOMException implementations don't allow calling DOMException's toString()
  // on non-DOMExceptions. Error's toString() is sufficient here.
  DOMEx[protoProp] = Error[protoProp];
  classListProto.item = function (i) {
    return this[i] || null;
  };
  classListProto.contains = function (token) {
    token += "";
    return checkTokenAndGetIndex(this, token) !== -1;
  };
  classListProto.add = function (token) {
    token += "";
    if (checkTokenAndGetIndex(this, token) === -1) {
      this.push(token);
      this._updateClassName();
    }
  };
  classListProto.remove = function (token) {
    token += "";
    var index = checkTokenAndGetIndex(this, token);
    if (index !== -1) {
      this.splice(index, 1);
      this._updateClassName();
    }
  };
  classListProto.toggle = function (token) {
    token += "";
    if (checkTokenAndGetIndex(this, token) === -1) {
      this.add(token);
    } else {
      this.remove(token);
    }
  };
  classListProto.toString = function () {
    return this.join(" ");
  };
  
  if (objCtr.defineProperty) {
    var classListPropDesc = {
        get: classListGetter
      , enumerable: true
      , configurable: true
    };
    try {
      objCtr.defineProperty(elemCtrProto, classListProp, classListPropDesc);
    } catch (ex) { // IE 8 doesn't support enumerable:true
      if (ex.number === -0x7FF5EC54) {
        classListPropDesc.enumerable = false;
        objCtr.defineProperty(elemCtrProto, classListProp, classListPropDesc);
      }
    }
  } else if (objCtr[protoProp].__defineGetter__) {
    elemCtrProto.__defineGetter__(classListProp, classListGetter);
  }
  
  }(self));
  
  }
  /* ---------------------------------------------------------------------- */
  
  /* Slide movement */
  
  function getSlideEl(no) {
    if ((no < 0) || (no >= slideEls.length)) {
      return null;
    } else {
      return slideEls[no];
    }
  };
  
  function updateSlideClass(slideNo, className) {
    var el = getSlideEl(slideNo);
  
    if (!el) {
      return;
    }
  
    if (className) {
      el.classList.add(className);
    }
  
    for (var i in SLIDE_CLASSES) {
      if (className != SLIDE_CLASSES[i]) {
        el.classList.remove(SLIDE_CLASSES[i]);
      }
    }
  };
  
  function updateSlides() {
    for (var i = 0; i < slideEls.length; i++) {
      switch (i) {
        case curSlide - 2:
          updateSlideClass(i, 'far-past');
          break;
        case curSlide - 1:
          updateSlideClass(i, 'past');
          break;
        case curSlide:
          updateSlideClass(i, 'current');
          break;
        case curSlide + 1:
          updateSlideClass(i, 'next');
          break;
        case curSlide + 2:
          updateSlideClass(i, 'far-next');
          break;
        default:
          updateSlideClass(i);
          break;
      }
    }
  
    triggerLeaveEvent(curSlide - 1);
    triggerEnterEvent(curSlide);
  
    window.setTimeout(function() {
      // Hide after the slide
      disableSlideFrames(curSlide - 2);
    }, 301);
  
    enableSlideFrames(curSlide - 1);
    enableSlideFrames(curSlide + 2);
  
    updateHash();
  };
  
  function prevSlide() {
    if (curSlide > 0) {
      curSlide--;
  
      updateSlides();
    }
  };
  
  function nextSlide() {
    if (curSlide < slideEls.length - 1) {
      curSlide++;
  
      updateSlides();
    }
  };
  
  /* Slide events */
  
  function triggerEnterEvent(no) {
    var el = getSlideEl(no);
    if (!el) {
      return;
    }
  
    var onEnter = el.getAttribute('onslideenter');
    if (onEnter) {
      new Function(onEnter).call(el);
    }
  
    var evt = document.createEvent('Event');
    evt.initEvent('slideenter', true, true);
    evt.slideNumber = no + 1; // Make it readable
  
    el.dispatchEvent(evt);
  };
  
  function triggerLeaveEvent(no) {
    var el = getSlideEl(no);
    if (!el) {
      return;
    }
  
    var onLeave = el.getAttribute('onslideleave');
    if (onLeave) {
      new Function(onLeave).call(el);
    }
  
    var evt = document.createEvent('Event');
    evt.initEvent('slideleave', true, true);
    evt.slideNumber = no + 1; // Make it readable
  
    el.dispatchEvent(evt);
  };
  
  /* Touch events */
  
  function handleTouchStart(event) {
    if (event.touches.length == 1) {
      touchDX = 0;
      touchDY = 0;
  
      touchStartX = event.touches[0].pageX;
      touchStartY = event.touches[0].pageY;
  
      document.body.addEventListener('touchmove', handleTouchMove, true);
      document.body.addEventListener('touchend', handleTouchEnd, true);
    }
  };
  
  function handleTouchMove(event) {
    if (event.touches.length > 1) {
      cancelTouch();
    } else {
      touchDX = event.touches[0].pageX - touchStartX;
      touchDY = event.touches[0].pageY - touchStartY;
      event.preventDefault();
    }
  };
  
  function handleTouchEnd(event) {
    var dx = Math.abs(touchDX);
    var dy = Math.abs(touchDY);
  
    if ((dx > PM_TOUCH_SENSITIVITY) && (dy < (dx * 2 / 3))) {
      if (touchDX > 0) {
        prevSlide();
      } else {
        nextSlide();
      }
    }
  
    cancelTouch();
  };
  
  function cancelTouch() {
    document.body.removeEventListener('touchmove', handleTouchMove, true);
    document.body.removeEventListener('touchend', handleTouchEnd, true);
  };
  
  /* Preloading frames */
  
  function disableSlideFrames(no) {
    var el = getSlideEl(no);
    if (!el) {
      return;
    }
  
    var frames = el.getElementsByTagName('iframe');
    for (var i = 0, frame; frame = frames[i]; i++) {
      disableFrame(frame);
    }
  };
  
  function enableSlideFrames(no) {
    var el = getSlideEl(no);
    if (!el) {
      return;
    }
  
    var frames = el.getElementsByTagName('iframe');
    for (var i = 0, frame; frame = frames[i]; i++) {
      enableFrame(frame);
    }
  };
  
  function disableFrame(frame) {
    frame.src = 'about:blank';
  };
  
  function enableFrame(frame) {
    var src = frame._src;
  
    if (frame.src != src && src != 'about:blank') {
      frame.src = src;
    }
  };
  
  function setupFrames() {
    var frames = document.querySelectorAll('iframe');
    for (var i = 0, frame; frame = frames[i]; i++) {
      frame._src = frame.src;
      disableFrame(frame);
    }
  
    enableSlideFrames(curSlide);
    enableSlideFrames(curSlide + 1);
    enableSlideFrames(curSlide + 2);
  };
  
  function setupInteraction() {
    /* Clicking and tapping */
  
    var el = document.createElement('div');
    el.className = 'slide-area';
    el.id = 'prev-slide-area';
    el.addEventListener('click', prevSlide, false);
    document.querySelector('section.slides').appendChild(el);
  
    var el = document.createElement('div');
    el.className = 'slide-area';
    el.id = 'next-slide-area';
    el.addEventListener('click', nextSlide, false);
    document.querySelector('section.slides').appendChild(el);
  
    /* Swiping */
  
    document.body.addEventListener('touchstart', handleTouchStart, false);
  }
  
  /* Hash functions */
  
  function getCurSlideFromHash() {
    var slideNo = parseInt(location.hash.substr(1));
  
    if (slideNo) {
      curSlide = slideNo - 1;
    } else {
      curSlide = 0;
    }
  };
  
  function updateHash() {
    location.replace('#' + (curSlide + 1));
  };
  
  /* Event listeners */
  
  function handleBodyKeyDown(event) {
    // If we're in a code element, only handle pgup/down.
    var inCode = event.target.classList.contains("code");
    var hiddenBullets;
  
    switch (event.keyCode) {
      case 39: // right arrow
      case 13: // Enter
      case 32: // space
        if (inCode) break;
      case 34: // PgDn
        hiddenBullets = $('.current').find('li, p, .code, > .buttons').filter(':hidden');
        if(hiddenBullets.length > 0) {
            $(hiddenBullets[0]).show();
        }
        else {
            nextSlide();
        }
        event.preventDefault();
        break;
  
      case 37: // left arrow
      case 8: // Backspace
        if (inCode) break;
      case 33: // PgUp
        prevSlide();
        event.preventDefault();
        break;
  
      case 40: // down arrow
        if (inCode) break;
        nextSlide();
        event.preventDefault();
        break;
  
      case 38: // up arrow
        if (inCode) break;
        prevSlide();
        event.preventDefault();
        break;
    }
  };
  
  function addEventListeners() {
    document.addEventListener('keydown', handleBodyKeyDown, false);
  };
  
  /* Initialization */
  
  function addFontStyle() {
    var el = document.createElement('link');
    el.rel = 'stylesheet';
    el.type = 'text/css';
    el.href = '//fonts.googleapis.com/css?family=' +
              'Open+Sans:regular,semibold,italic,italicsemibold|Droid+Sans+Mono';
  
    document.body.appendChild(el);
  };
  
  function addGeneralStyle() {
    var el = document.createElement('link');
    el.rel = 'stylesheet';
    el.type = 'text/css';
    el.href = PERMANENT_URL_PREFIX + 'styles.css';
    document.body.appendChild(el);
  
    var el = document.createElement('meta');
    el.name = 'viewport';
    el.content = 'width=1100,height=750';
    document.querySelector('head').appendChild(el);
  
    var el = document.createElement('meta');
    el.name = 'apple-mobile-web-app-capable';
    el.content = 'yes';
    document.querySelector('head').appendChild(el);
  };
  
  function addPrintStyle() {
    var el = document.createElement('link');
    el.rel = 'stylesheet';
    el.type = 'text/css';
    el.media = "print";
    el.href = PERMANENT_URL_PREFIX + 'print.css';
    document.body.appendChild(el);
  };
  
  function handleDomLoaded() {
    slideEls = document.querySelectorAll('section.slides > article');
  
    setupFrames();
  
    addFontStyle();
    addGeneralStyle();
    addPrintStyle();
    addEventListeners();
  
    updateSlides();
  
    setupInteraction();
  
    document.body.classList.add('loaded');
  };
  
  function initialize() {
    getCurSlideFromHash();
  
    if (window['_DEBUG']) {
      PERMANENT_URL_PREFIX = '../';
    }
  
    if (window['_DCL']) {
      handleDomLoaded();
    } else {
      document.addEventListener('DOMContentLoaded', handleDomLoaded, false);
    }
  }
  
  // If ?debug exists then load the script relative instead of absolute
  if (!window['_DEBUG'] && document.location.href.indexOf('?debug') !== -1) {
    document.addEventListener('DOMContentLoaded', function() {
      // Avoid missing the DomContentLoaded event
      window['_DCL'] = true
    }, false);
  
    window['_DEBUG'] = true;
    var script = document.createElement('script');
    script.type = 'text/javascript';
    script.src = '../slides.js';
    var s = document.getElementsByTagName('script')[0];
    s.parentNode.insertBefore(script, s);
  
    // Remove this script
    s.parentNode.removeChild(s);
  } else {
    initialize();
  }
  