/*! PhotoSwipe - v4.1.3 - 2019-01-08
 * http://photoswipe.com
 * Copyright (c) 2019 Dmitry Semenov; */

(function (root, factory) {
  if (typeof define === "function" && define.amd) {define(factory);} else if (typeof exports === "object") {
    module.exports = factory();
  } else {
    root.PhotoSwipe = factory();
  }
})(this, function () {
  "use strict";
  var PhotoSwipe = function (template, UiClass, items, options) {
    /*>>framework-bridge*/
    /**
     *
     * Set of generic functions used by gallery.
     *
     * You're free to modify anything here as long as functionality is kept.
     *
     */

    var framework = {
      features: null,
      bind: function (target, type, listener, unbind) {
        var methodName = (unbind ? "remove" : "add") + "EventListener";
        type = type.split(" ");
        for (var i = 0; i < type.length; i++) {
          if (type[i]) {
            target[methodName](type[i], listener, false);
          }
        }
      },
      isArray: function (obj) {
        return obj instanceof Array;
      },
      createEl: function (classes, tag) {
        var el = document.createElement(tag || "div");
        if (classes) {
          el.className = classes;
        }
        return el;
      },
      getScrollY: function () {
        var yOffset = window.pageYOffset;
        return yOffset !== undefined
          ? yOffset
          : document.documentElement.scrollTop;
      },
      unbind: function (target, type, listener) {
        framework.bind(target, type, listener, true);
      },
      removeClass: function (el, className) {
        var reg = new RegExp("(\\s|^)" + className + "(\\s|$)");
        el.className = el.className
          .replace(reg, " ")
          .replace(/^\s\s*/, "")
          .replace(/\s\s*$/, "");
      },
      addClass: function (el, className) {
        if (!framework.hasClass(el, className)) {
          el.className += (el.className ? " " : "") + className;
        }
      },
      hasClass: function (el, className) {
        return (
          el.className &&
          new RegExp("(^|\\s)" + className + "(\\s|$)").test(el.className)
        );
      },
      getChildByClass: function (parentEl, childClassName) {
        var node = parentEl.firstChild;
        while (node) {
          if (framework.hasClass(node, childClassName)) {
            return node;
          }
          node = node.nextSibling;
        }
      },
      arraySearch: function (array, value, key) {
        var i = array.length;
        while (i--) {
          if (array[i][key] === value) {
            return i;
          }
        }
        return -1;
      },
      extend: function (o1, o2, preventOverwrite) {
        for (var prop in o2) {
          if (o2.hasOwnProperty(prop)) {
            if (preventOverwrite && o1.hasOwnProperty(prop)) {continue;}
            o1[prop] = o2[prop];
          }
        }
      },
      easing: {
        sine: {
          out: function (k) {
            return Math.sin(k * (Math.PI / 2));
          },
          inOut: function (k) {
            return -(Math.cos(Math.PI * k) - 1) / 2;
          },
        },
        cubic: {
          out: function (k) {
            return --k * k * k + 1;
          },
        },
        /*
			elastic: {
				out: function ( k ) {

					var s, a = 0.1, p = 0.4;
					if ( k === 0 ) return 0;
					if ( k === 1 ) return 1;
					if ( !a || a < 1 ) { a = 1; s = p / 4; }
					else s = p * Math.asin( 1 / a ) / ( 2 * Math.PI );
					return ( a * Math.pow( 2, - 10 * k) * Math.sin( ( k - s ) * ( 2 * Math.PI ) / p ) + 1 );

				},
			},
			back: {
				out: function ( k ) {
					var s = 1.70158;
					return --k * k * ( ( s + 1 ) * k + s ) + 1;
				}
			}
		*/
      },

      /**
       *
       * @return {object}
       *
       * {
       *  raf : request animation frame function
       *  caf : cancel animation frame function
       *  transfrom : transform property key (with vendor), or null if not supported
       *  oldIE : IE8 or below
       * }
       *
       */
      detectFeatures: function () {
        if (framework.features) {
          return framework.features;
        }
        var helperEl = framework.createEl(),
          helperStyle = helperEl.style,
          vendor = "",
          features = {};

        // IE8 and below
        features.oldIE = document.all && !document.addEventListener;

        features.touch = "ontouchstart" in window;

        if (window.requestAnimationFrame) {
          features.raf = window.requestAnimationFrame;
          features.caf = window.cancelAnimationFrame;
        }

        features.pointerEvent =
          !!window.PointerEvent || navigator.msPointerEnabled;

        // fix false-positive detection of old Android in new IE
        // (IE11 ua string contains "Android 4.0")

        if (!features.pointerEvent) {
          var ua = navigator.userAgent;

          // Detect if device is iPhone or iPod and if it's older than iOS 8
          // http://stackoverflow.com/a/14223920
          //
          // This detection is made because of buggy top/bottom toolbars
          // that don't trigger window.resize event.
          // For more info refer to _isFixedPosition variable in core.js

          if (/iP(hone|od)/.test(navigator.platform)) {
            var v = navigator.appVersion.match(/OS (\d+)_(\d+)_?(\d+)?/);
            if (v && v.length > 0) {
              v = parseInt(v[1], 10);
              if (v >= 1 && v < 8) {
                features.isOldIOSPhone = true;
              }
            }
          }

          // Detect old Android (before KitKat)
          // due to bugs related to position:fixed
          // http://stackoverflow.com/questions/7184573/pick-up-the-android-version-in-the-browser-by-javascript

          var match = ua.match(/Android\s([0-9\.]*)/);
          var androidversion = match ? match[1] : 0;
          androidversion = parseFloat(androidversion);
          if (androidversion >= 1) {
            if (androidversion < 4.4) {
              features.isOldAndroid = true; // for fixed position bug & performance
            }
            features.androidVersion = androidversion; // for touchend bug
          }
          features.isMobileOpera = /opera mini|opera mobi/i.test(ua);

          // p.s. yes, yes, UA sniffing is bad, propose your solution for above bugs.
        }

        var styleChecks = ["transform", "perspective", "animationName"],
          vendors = ["", "webkit", "Moz", "ms", "O"],
          styleCheckItem,
          styleName;

        for (var i = 0; i < 4; i++) {
          vendor = vendors[i];

          for (var a = 0; a < 3; a++) {
            styleCheckItem = styleChecks[a];

            // uppercase first letter of property name, if vendor is present
            styleName =
              vendor +
              (vendor
                ? styleCheckItem.charAt(0).toUpperCase() +
                  styleCheckItem.slice(1)
                : styleCheckItem);

            if (!features[styleCheckItem] && styleName in helperStyle) {
              features[styleCheckItem] = styleName;
            }
          }

          if (vendor && !features.raf) {
            vendor = vendor.toLowerCase();
            features.raf = window[vendor + "RequestAnimationFrame"];
            if (features.raf) {
              features.caf =
                window[vendor + "CancelAnimationFrame"] ||
                window[vendor + "CancelRequestAnimationFrame"];
            }
          }
        }

        if (!features.raf) {
          var lastTime = 0;
          features.raf = function (fn) {
            var currTime = new Date().getTime();
            var timeToCall = Math.max(0, 16 - (currTime - lastTime));
            var id = window.setTimeout(function () {
              fn(currTime + timeToCall);
            }, timeToCall);
            lastTime = currTime + timeToCall;
            return id;
          };
          features.caf = function (id) {clearTimeout(id);};
        }

        // Detect SVG support
        features.svg =
          !!document.createElementNS &&
          !!document.createElementNS("http://www.w3.org/2000/svg", "svg")
            .createSVGRect;

        framework.features = features;

        return features;
      },
    };

    framework.detectFeatures();

    // Override addEventListener for old versions of IE
    if (framework.features.oldIE) {
      framework.bind = function (target, type, listener, unbind) {
        type = type.split(" ");

        var methodName = (unbind ? "detach" : "attach") + "Event",
          evName,
          _handleEv = function () {listener.handleEvent.call(listener);};

        for (var i = 0; i < type.length; i++) {
          evName = type[i];
          if (evName) {
            if (typeof listener === "object" && listener.handleEvent) {
              if (!unbind) {
                listener["oldIE" + evName] = _handleEv;
              } else {
                if (!listener["oldIE" + evName]) {
                  return false;
                }
              }

              target[methodName]("on" + evName, listener["oldIE" + evName]);
            } else {
              target[methodName]("on" + evName, listener);
            }
          }
        }
      };
    }

    /*>>framework-bridge*/

    /*>>core*/
    //function(template, UiClass, items, options)

    var self = this;

    //used later for a11y

    /**
     * Static vars, don't change unless you know what you're doing.
     */
    var DOUBLE_TAP_RADIUS = 25,
      NUM_HOLDERS = 3;

    /**
     * Options
     */
    var _options = {
      allowPanToNext: true,
      spacing: 0.12,
      bgOpacity: 1,
      mouseUsed: false,
      loop: true,
      pinchToClose: true,
      closeOnScroll: true,
      closeOnVerticalDrag: true,
      verticalDragRange: 0.75,
      hideAnimationDuration: 333,
      showAnimationDuration: 333,
      showHideOpacity: false,
      focus: true,
      escKey: true,
      arrowKeys: true,
      mainScrollEndFriction: 0.35,
      panEndFriction: 0.35,
      isClickableElement: function (el) {
        return el.tagName === "A";
      },
      getDoubleTapZoom: function (isMouseClick, item) {
        if (isMouseClick) {
          return 1;
        } else {
          return item.initialZoomLevel < 0.7 ? 1 : 1.33;
        }
      },
      maxSpreadZoom: 1.33,
      modal: true,

      // not fully implemented yet
      scaleMode: "fit", // TODO
    };
    framework.extend(_options, options);

    /**
     * Private helper variables & functions
     */

    var _getEmptyPoint = function () {
      return { x: 0, y: 0 };
    };

    var _isOpen,
      _isDestroying,
      _closedByScroll,
      _currentItemIndex,
      _containerStyle,
      _containerShiftIndex,
      _currPanDist = _getEmptyPoint(),
      _startPanOffset = _getEmptyPoint(),
      _panOffset = _getEmptyPoint(),
      _upMoveEvents, // drag move, drag end & drag cancel events array
      _downEvents, // drag start events array
      _globalEventHandlers,
      _viewportSize = {},
      _currZoomLevel,
      _startZoomLevel,
      _translatePrefix,
      _translateSufix,
      _updateSizeInterval,
      _itemsNeedUpdate,
      _currPositionIndex = 0,
      _offset = {},
      _slideSize = _getEmptyPoint(), // size of slide area, including spacing
      _itemHolders,
      _prevItemIndex,
      _indexDiff = 0, // difference of indexes since last content update
      _dragStartEvent,
      _dragMoveEvent,
      _dragEndEvent,
      _dragCancelEvent,
      _transformKey,
      _pointerEventEnabled,
      _isFixedPosition = true,
      _likelyTouchDevice,
      _modules = [],
      _requestAF,
      _cancelAF,
      _initalClassName,
      _initalWindowScrollY,
      _oldIE,
      _currentWindowScrollY,
      _features,
      _windowVisibleSize = {},
      _renderMaxResolution = false,
      _orientationChangeTimeout,
      // Registers PhotoSWipe module (History, Controller ...)
      _registerModule = function (name, module) {
        framework.extend(self, module.publicMethods);
        _modules.push(name);
      },
      _getLoopedId = function (index) {
        var numSlides = _getNumItems();
        if (index > numSlides - 1) {
          return index - numSlides;
        } else if (index < 0) {
          return numSlides + index;
        }
        return index;
      },
      // Micro bind/trigger
      _listeners = {},
      _listen = function (name, fn) {
        if (!_listeners[name]) {
          _listeners[name] = [];
        }
        return _listeners[name].push(fn);
      },
      _shout = function (name) {
        var listeners = _listeners[name];

        if (listeners) {
          var args = Array.prototype.slice.call(arguments);
          args.shift();

          for (var i = 0; i < listeners.length; i++) {
            listeners[i].apply(self, args);
          }
        }
      },
      _getCurrentTime = function () {
        return new Date().getTime();
      },
      _applyBgOpacity = function (opacity) {
        _bgOpacity = opacity;
        self.bg.style.opacity = opacity * _options.bgOpacity;
      },
      _applyZoomTransform = function (styleObj, x, y, zoom, item) {
        if (!_renderMaxResolution || (item && item !== self.currItem)) {
          zoom = zoom / (item ? item.fitRatio : self.currItem.fitRatio);
        }

        styleObj[_transformKey] =
          _translatePrefix +
          x +
          "px, " +
          y +
          "px" +
          _translateSufix +
          " scale(" +
          zoom +
          ")";
      },
      _applyCurrentZoomPan = function (allowRenderResolution) {
        if (_currZoomElementStyle) {
          if (allowRenderResolution) {
            if (_currZoomLevel > self.currItem.fitRatio) {
              if (!_renderMaxResolution) {
                _setImageSize(self.currItem, false, true);
                _renderMaxResolution = true;
              }
            } else {
              if (_renderMaxResolution) {
                _setImageSize(self.currItem);
                _renderMaxResolution = false;
              }
            }
          }

          _applyZoomTransform(
            _currZoomElementStyle,
            _panOffset.x,
            _panOffset.y,
            _currZoomLevel
          );
        }
      },
      _applyZoomPanToItem = function (item) {
        if (item.container) {
          _applyZoomTransform(
            item.container.style,
            item.initialPosition.x,
            item.initialPosition.y,
            item.initialZoomLevel,
            item
          );
        }
      },
      _setTranslateX = function (x, elStyle) {
        elStyle[_transformKey] =
          _translatePrefix + x + "px, 0px" + _translateSufix;
      },
      _moveMainScroll = function (x, dragging) {
        if (!_options.loop && dragging) {
          var newSlideIndexOffset =
              _currentItemIndex +
              (_slideSize.x * _currPositionIndex - x) / _slideSize.x,
            delta = Math.round(x - _mainScrollPos.x);

          if (
            (newSlideIndexOffset < 0 && delta > 0) ||
            (newSlideIndexOffset >= _getNumItems() - 1 && delta < 0)
          ) {
            x = _mainScrollPos.x + delta * _options.mainScrollEndFriction;
          }
        }

        _mainScrollPos.x = x;
        _setTranslateX(x, _containerStyle);
      },
      _calculatePanOffset = function (axis, zoomLevel) {
        var m = _midZoomPoint[axis] - _offset[axis];
        return (
          _startPanOffset[axis] +
          _currPanDist[axis] +
          m -
          m * (zoomLevel / _startZoomLevel)
        );
      },
      _equalizePoints = function (p1, p2) {
        p1.x = p2.x;
        p1.y = p2.y;
        if (p2.id) {
          p1.id = p2.id;
        }
      },
      _roundPoint = function (p) {
        p.x = Math.round(p.x);
        p.y = Math.round(p.y);
      },
      _mouseMoveTimeout = null,
      _onFirstMouseMove = function () {
        // Wait until mouse move event is fired at least twice during 100ms
        // We do this, because some mobile browsers trigger it on touchstart
        if (_mouseMoveTimeout) {
          framework.unbind(document, "mousemove", _onFirstMouseMove);
          framework.addClass(template, "pswp--has_mouse");
          _options.mouseUsed = true;
          _shout("mouseUsed");
        }
        _mouseMoveTimeout = setTimeout(function () {
          _mouseMoveTimeout = null;
        }, 100);
      },
      _bindEvents = function () {
        framework.bind(document, "keydown", self);

        if (_features.transform) {
          // don't bind click event in browsers that don't support transform (mostly IE8)
          framework.bind(self.scrollWrap, "click", self);
        }

        if (!_options.mouseUsed) {
          framework.bind(document, "mousemove", _onFirstMouseMove);
        }

        framework.bind(window, "resize scroll orientationchange", self);

        _shout("bindEvents");
      },
      _unbindEvents = function () {
        framework.unbind(window, "resize scroll orientationchange", self);
        framework.unbind(window, "scroll", _globalEventHandlers.scroll);
        framework.unbind(document, "keydown", self);
        framework.unbind(document, "mousemove", _onFirstMouseMove);

        if (_features.transform) {
          framework.unbind(self.scrollWrap, "click", self);
        }

        if (_isDragging) {
          framework.unbind(window, _upMoveEvents, self);
        }

        clearTimeout(_orientationChangeTimeout);

        _shout("unbindEvents");
      },
      _calculatePanBounds = function (zoomLevel, update) {
        var bounds = _calculateItemSize(
          self.currItem,
          _viewportSize,
          zoomLevel
        );
        if (update) {
          _currPanBounds = bounds;
        }
        return bounds;
      },
      _getMinZoomLevel = function (item) {
        if (!item) {
          item = self.currItem;
        }
        return item.initialZoomLevel;
      },
      _getMaxZoomLevel = function (item) {
        if (!item) {
          item = self.currItem;
        }
        return item.w > 0 ? _options.maxSpreadZoom : 1;
      },
      // Return true if offset is out of the bounds
      _modifyDestPanOffset = function (
        axis,
        destPanBounds,
        destPanOffset,
        destZoomLevel
      ) {
        if (destZoomLevel === self.currItem.initialZoomLevel) {
          destPanOffset[axis] = self.currItem.initialPosition[axis];
          return true;
        } else {
          destPanOffset[axis] = _calculatePanOffset(axis, destZoomLevel);

          if (destPanOffset[axis] > destPanBounds.min[axis]) {
            destPanOffset[axis] = destPanBounds.min[axis];
            return true;
          } else if (destPanOffset[axis] < destPanBounds.max[axis]) {
            destPanOffset[axis] = destPanBounds.max[axis];
            return true;
          }
        }
        return false;
      },
      _setupTransforms = function () {
        if (_transformKey) {
          // setup 3d transforms
          var allow3dTransform = _features.perspective && !_likelyTouchDevice;
          _translatePrefix = "translate" + (allow3dTransform ? "3d(" : "(");
          _translateSufix = _features.perspective ? ", 0px)" : ")";
          return;
        }

        // Override zoom/pan/move functions in case old browser is used (most likely IE)
        // (so they use left/top/width/height, instead of CSS transform)

        _transformKey = "left";
        framework.addClass(template, "pswp--ie");

        _setTranslateX = function (x, elStyle) {
          elStyle.left = x + "px";
        };
        _applyZoomPanToItem = function (item) {
          var zoomRatio = item.fitRatio > 1 ? 1 : item.fitRatio,
            s = item.container.style,
            w = zoomRatio * item.w,
            h = zoomRatio * item.h;

          s.width = w + "px";
          s.height = h + "px";
          s.left = item.initialPosition.x + "px";
          s.top = item.initialPosition.y + "px";
        };
        _applyCurrentZoomPan = function () {
          if (_currZoomElementStyle) {
            var s = _currZoomElementStyle,
              item = self.currItem,
              zoomRatio = item.fitRatio > 1 ? 1 : item.fitRatio,
              w = zoomRatio * item.w,
              h = zoomRatio * item.h;

            s.width = w + "px";
            s.height = h + "px";

            s.left = _panOffset.x + "px";
            s.top = _panOffset.y + "px";
          }
        };
      },
      _onKeyDown = function (e) {
        var keydownAction = "";
        if (_options.escKey && e.keyCode === 27) {
          keydownAction = "close";
        } else if (_options.arrowKeys) {
          if (e.keyCode === 37) {
            keydownAction = "prev";
          } else if (e.keyCode === 39) {
            keydownAction = "next";
          }
        }

        if (keydownAction) {
          // don't do anything if special key pressed to prevent from overriding default browser actions
          // e.g. in Chrome on Mac cmd+arrow-left returns to previous page
          if (!e.ctrlKey && !e.altKey && !e.shiftKey && !e.metaKey) {
            if (e.preventDefault) {e.preventDefault();} else {
              e.returnValue = false;
            }
            self[keydownAction]();
          }
        }
      },
      _onGlobalClick = function (e) {
        if (!e) {return;}

        // don't allow click event to pass through when triggering after drag or some other gesture
        if (
          _moved ||
          _zoomStarted ||
          _mainScrollAnimating ||
          _verticalDragInitiated
        ) {
          e.preventDefault();
          e.stopPropagation();
        }
      },
      _updatePageScrollOffset = function () {
        self.setScrollOffset(0, framework.getScrollY());
      };

    // Micro animation engine
    var _animations = {},
      _numAnimations = 0,
      _stopAnimation = function (name) {
        if (_animations[name]) {
          if (_animations[name].raf) {_cancelAF(_animations[name].raf);}
          _numAnimations--;
          delete _animations[name];
        }
      },
      _registerStartAnimation = function (name) {
        if (_animations[name]) {_stopAnimation(name);}
        if (!_animations[name]) {
          _numAnimations++;
          _animations[name] = {};}
      },
      _stopAllAnimations = function () {
        for (var prop in _animations) {
          if (_animations.hasOwnProperty(prop)) {_stopAnimation(prop);}
        }
      },
      _animateProp = function (
        name,
        b,
        endProp,
        d,
        easingFn,
        onUpdate,
        onComplete
      ) {
        var startAnimTime = _getCurrentTime(),
          t;
        _registerStartAnimation(name);

        var animloop = function () {
          if (_animations[name]) {
            t = _getCurrentTime() - startAnimTime; // time diff
            //b - beginning (start prop)
            //d - anim duration

            if (t >= d) {
              _stopAnimation(name);
              onUpdate(endProp);
              if (onComplete) {onComplete();}
              return;
            }
            onUpdate((endProp - b) * easingFn(t / d) + b);

            _animations[name].raf = _requestAF(animloop);
          }
        };
        animloop();
      };

    var publicMethods = {
      // make a few local variables and functions public
      shout: _shout,
      listen: _listen,
      viewportSize: _viewportSize,
      options: _options,

      isMainScrollAnimating: function () {
        return _mainScrollAnimating;
      },
      getZoomLevel: function () {
        return _currZoomLevel;
      },
      getCurrentIndex: function () {
        return _currentItemIndex;
      },
      isDragging: function () {
        return _isDragging;
      },
      isZooming: function () {
        return _isZooming;
      },
      setScrollOffset: function (x, y) {
        _offset.x = x;
        _currentWindowScrollY = _offset.y = y;
        _shout("updateScrollOffset", _offset);
      },
      applyZoomPan: function (zoomLevel, panX, panY, allowRenderResolution) {
        _panOffset.x = panX;
        _panOffset.y = panY;
        _currZoomLevel = zoomLevel;
        _applyCurrentZoomPan(allowRenderResolution);
      },

      init: function () {
        if (_isOpen || _isDestroying) {return;}

        var i;

        self.framework = framework; // basic functionality
        self.template = template; // root DOM element of PhotoSwipe
        self.bg = framework.getChildByClass(template, "pswp__bg");

        _initalClassName = template.className;
        _isOpen = true;

        _features = framework.detectFeatures();
        _requestAF = _features.raf;
        _cancelAF = _features.caf;
        _transformKey = _features.transform;
        _oldIE = _features.oldIE;

        self.scrollWrap = framework.getChildByClass(
          template,
          "pswp__scroll-wrap"
        );
        self.container = framework.getChildByClass(
          self.scrollWrap,
          "pswp__container"
        );

        _containerStyle = self.container.style; // for fast access

        // Objects that hold slides (there are only 3 in DOM)
        self.itemHolders = _itemHolders = [
          { el: self.container.children[0], wrap: 0, index: -1 },
          { el: self.container.children[1], wrap: 0, index: -1 },
          { el: self.container.children[2], wrap: 0, index: -1 },
        ];

        // hide nearby item holders until initial zoom animation finishes (to avoid extra Paints)
        _itemHolders[0].el.style.display = _itemHolders[2].el.style.display =
          "none";

        _setupTransforms();

        // Setup global events
        _globalEventHandlers = {
          resize: self.updateSize,

          // Fixes: iOS 10.3 resize event
          // does not update scrollWrap.clientWidth instantly after resize
          // https://github.com/dimsemenov/PhotoSwipe/issues/1315
          orientationchange: function () {
            clearTimeout(_orientationChangeTimeout);
            _orientationChangeTimeout = setTimeout(function () {
              if (_viewportSize.x !== self.scrollWrap.clientWidth) {self.updateSize();}
            }, 500);
          },
          scroll: _updatePageScrollOffset,
          keydown: _onKeyDown,
          click: _onGlobalClick,
        };

        // disable show/hide effects on old browsers that don't support CSS animations or transforms,
        // old IOS, Android and Opera mobile. Blackberry seems to work fine, even older models.
        var oldPhone =
          _features.isOldIOSPhone ||
          _features.isOldAndroid ||
          _features.isMobileOpera;
        if (!_features.animationName || !_features.transform || oldPhone) {
          _options.showAnimationDuration = _options.hideAnimationDuration = 0;
        }

        // init modules
        for (i = 0; i < _modules.length; i++) {
          self["init" + _modules[i]]();
        }

        // init
        if (UiClass) {
          var ui = (self.ui = new UiClass(self, framework));
          ui.init();
        }

        _shout("firstUpdate");
        _currentItemIndex = _currentItemIndex || _options.index || 0;
        // validate index
        if (
          isNaN(_currentItemIndex) ||
          _currentItemIndex < 0 ||
          _currentItemIndex >= _getNumItems()
        ) {
          _currentItemIndex = 0;
        }
        self.currItem = _getItemAt(_currentItemIndex);

        if (_features.isOldIOSPhone || _features.isOldAndroid) {
          _isFixedPosition = false;
        }

        template.setAttribute("aria-hidden", "false");
        if (_options.modal) {
          if (!_isFixedPosition) {
            template.style.position = "absolute";
            template.style.top = framework.getScrollY() + "px";
          } else {
            template.style.position = "fixed";
          }
        }

        if (_currentWindowScrollY === undefined) {
          _shout("initialLayout");
          _currentWindowScrollY = _initalWindowScrollY = framework.getScrollY();
        }

        //accessibility improvement fixes loss of focus
        //this would be simpler in jQuery

        var list, index;
        list = document.getElementsByClassName("base");
        for (index = 0; index < list.length; ++index) {
          list[index].setAttribute("aria-hidden", "true");
        }

        // add classes to root element of PhotoSwipe
        var rootClasses = "pswp--open ";
        if (_options.mainClass) {
          rootClasses += _options.mainClass + " ";
        }
        if (_options.showHideOpacity) {
          rootClasses += "pswp--animate_opacity ";
        }
        rootClasses += _likelyTouchDevice ? "pswp--touch" : "pswp--notouch";
        rootClasses += _features.animationName ? " pswp--css_animation" : "";
        rootClasses += _features.svg ? " pswp--svg" : "";
        framework.addClass(template, rootClasses);

        self.updateSize();

        // initial update
        _containerShiftIndex = -1;
        _indexDiff = null;
        for (i = 0; i < NUM_HOLDERS; i++) {
          _setTranslateX(
            (i + _containerShiftIndex) * _slideSize.x,
            _itemHolders[i].el.style
          );
        }

        if (!_oldIE) {
          framework.bind(self.scrollWrap, _downEvents, self); // no dragging for old IE
        }

        _listen("initialZoomInEnd", function () {
          self.setContent(_itemHolders[0], _currentItemIndex - 1);
          self.setContent(_itemHolders[2], _currentItemIndex + 1);

          _itemHolders[0].el.style.display = _itemHolders[2].el.style.display =
            "block";

          if (_options.focus) {
            // focus causes layout,
            // which causes lag during the animation,
            // that's why we delay it untill the initial zoom transition ends
            template.focus();
          }

          _bindEvents();
        });

        // set content for center slide (first time)
        self.setContent(_itemHolders[1], _currentItemIndex);

        self.updateCurrItem();

        _shout("afterInit");

        if (!_isFixedPosition) {
          // On all versions of iOS lower than 8.0, we check size of viewport every second.
          //
          // This is done to detect when Safari top & bottom bars appear,
          // as this action doesn't trigger any events (like resize).
          //
          // On iOS8 they fixed this.
          //
          // 10 Nov 2014: iOS 7 usage ~40%. iOS 8 usage 56%.

          _updateSizeInterval = setInterval(function () {
            if (
              !_numAnimations &&
              !_isDragging &&
              !_isZooming &&
              _currZoomLevel === self.currItem.initialZoomLevel
            ) {self.updateSize();}
          }, 1000);
        }

        framework.addClass(template, "pswp--visible");
      },

      // Close the gallery, then destroy it
      close: function () {
        if (!_isOpen) {return;}

        _isOpen = false;
        _isDestroying = true;
        _shout("close");
        _unbindEvents();

        _showOrHide(self.currItem, null, true, self.destroy);
      },

      // destroys the gallery (unbinds events, cleans up intervals and timeouts to avoid memory leaks)
      destroy: function () {
        _shout("destroy");

        if (_showOrHideTimeout) {clearTimeout(_showOrHideTimeout);}

        template.setAttribute("aria-hidden", "true");
        template.className = _initalClassName;

        //a11y enhancements

        var list, index;
        list = document.getElementsByClassName("base");
        for (index = 0; index < list.length; ++index) {
          list[index].setAttribute("aria-hidden", "false");
        }

        //a11y enhancement keeps focus on the first image of any gallery that is closed

        //need the id of the current gallery to focus the appropriate figure

        //first make an array of the properties of the item that is being destroyed

        var objectArray = Object.entries(self.currItem);

        //get the id of the next sibling

        var justElement = objectArray[6][1].childNodes[0].nextSibling.id;

        //set focus to the link of the closed image

        document.querySelector("#" + justElement).focus();

        if (_updateSizeInterval) {clearInterval(_updateSizeInterval);}

        framework.unbind(self.scrollWrap, _downEvents, self);

        // we unbind scroll event at the end, as closing animation may depend on it
        framework.unbind(window, "scroll", self);

        _stopDragUpdateLoop();

        _stopAllAnimations();

        _listeners = null;
      },

      /**
       * Pan image to position
       * @param {Number} x
       * @param {Number} y
       * @param {Boolean} force Will ignore bounds if set to true.
       */
      panTo: function (x, y, force) {
        if (!force) {
          if (x > _currPanBounds.min.x) {
            x = _currPanBounds.min.x;
          } else if (x < _currPanBounds.max.x) {
            x = _currPanBounds.max.x;
          }

          if (y > _currPanBounds.min.y) {
            y = _currPanBounds.min.y;
          } else if (y < _currPanBounds.max.y) {
            y = _currPanBounds.max.y;
          }
        }

        _panOffset.x = x;
        _panOffset.y = y;
        _applyCurrentZoomPan();
      },

      handleEvent: function (e) {
        e = e || window.event;
        if (_globalEventHandlers[e.type]) {_globalEventHandlers[e.type](e);}
      },

      goTo: function (index) {
        index = _getLoopedId(index);

        var diff = index - _currentItemIndex;
        _indexDiff = diff;

        _currentItemIndex = index;
        self.currItem = _getItemAt(_currentItemIndex);
        _currPositionIndex -= diff;

        _moveMainScroll(_slideSize.x * _currPositionIndex);

        _stopAllAnimations();
        _mainScrollAnimating = false;

        self.updateCurrItem();
      },
      next: function () {
        self.goTo(_currentItemIndex + 1);
      },
      prev: function () {
        self.goTo(_currentItemIndex - 1);
      },

      // update current zoom/pan objects
      updateCurrZoomItem: function (emulateSetContent) {
        if (emulateSetContent) {
          _shout("beforeChange", 0);
        }

        // itemHolder[1] is middle (current) item
        if (_itemHolders[1].el.children.length) {
          var zoomElement = _itemHolders[1].el.children[0];
          if (framework.hasClass(zoomElement, "pswp__zoom-wrap")) {
            _currZoomElementStyle = zoomElement.style;
          } else {
            _currZoomElementStyle = null;
          }
        } else {
          _currZoomElementStyle = null;
        }

        _currPanBounds = self.currItem.bounds;
        _startZoomLevel = _currZoomLevel = self.currItem.initialZoomLevel;

        _panOffset.x = _currPanBounds.center.x;
        _panOffset.y = _currPanBounds.center.y;

        if (emulateSetContent) {_shout("afterChange");}
      },

      invalidateCurrItems: function () {
        _itemsNeedUpdate = true;
        for (var i = 0; i < NUM_HOLDERS; i++) {
          if (_itemHolders[i].item) {
            _itemHolders[i].item.needsUpdate = true;
          }
        }
      },

      updateCurrItem: function (beforeAnimation) {
        if (_indexDiff === 0) {return;}

        var diffAbs = Math.abs(_indexDiff),
          tempHolder;

        if (beforeAnimation && diffAbs < 2) {return;}

        self.currItem = _getItemAt(_currentItemIndex);
        _renderMaxResolution = false;

        _shout("beforeChange", _indexDiff);

        if (diffAbs >= NUM_HOLDERS) {
          _containerShiftIndex +=
            _indexDiff + (_indexDiff > 0 ? -NUM_HOLDERS : NUM_HOLDERS);
          diffAbs = NUM_HOLDERS;
        }
        for (var i = 0; i < diffAbs; i++) {
          if (_indexDiff > 0) {
            tempHolder = _itemHolders.shift();
            _itemHolders[NUM_HOLDERS - 1] = tempHolder; // move first to last

            _containerShiftIndex++;
            _setTranslateX(
              (_containerShiftIndex + 2) * _slideSize.x,
              tempHolder.el.style
            );
            self.setContent(
              tempHolder,
              _currentItemIndex - diffAbs + i + 1 + 1
            );
          } else {
            tempHolder = _itemHolders.pop();
            _itemHolders.unshift(tempHolder); // move last to first

            _containerShiftIndex--;
            _setTranslateX(
              _containerShiftIndex * _slideSize.x,
              tempHolder.el.style
            );
            self.setContent(
              tempHolder,
              _currentItemIndex + diffAbs - i - 1 - 1
            );
          }
        }

        // reset zoom/pan on previous item
        if (_currZoomElementStyle && Math.abs(_indexDiff) === 1) {
          var prevItem = _getItemAt(_prevItemIndex);
          if (prevItem.initialZoomLevel !== _currZoomLevel) {
            _calculateItemSize(prevItem, _viewportSize);
            _setImageSize(prevItem);
            _applyZoomPanToItem(prevItem);
          }
        }

        // reset diff after update
        _indexDiff = 0;

        self.updateCurrZoomItem();

        _prevItemIndex = _currentItemIndex;

        _shout("afterChange");
      },

      updateSize: function (force) {
        if (!_isFixedPosition && _options.modal) {
          var windowScrollY = framework.getScrollY();
          if (_currentWindowScrollY !== windowScrollY) {
            template.style.top = windowScrollY + "px";
            _currentWindowScrollY = windowScrollY;
          }
          if (
            !force &&
            _windowVisibleSize.x === window.innerWidth &&
            _windowVisibleSize.y === window.innerHeight
          ) {return;}
          _windowVisibleSize.x = window.innerWidth;
          _windowVisibleSize.y = window.innerHeight;

          //template.style.width = _windowVisibleSize.x + 'px';
          template.style.height = _windowVisibleSize.y + "px";
        }

        _viewportSize.x = self.scrollWrap.clientWidth;
        _viewportSize.y = self.scrollWrap.clientHeight;

        _updatePageScrollOffset();

        _slideSize.x =
          _viewportSize.x + Math.round(_viewportSize.x * _options.spacing);
        _slideSize.y = _viewportSize.y;

        _moveMainScroll(_slideSize.x * _currPositionIndex);

        _shout("beforeResize"); // even may be used for example to switch image sources

        // don't re-calculate size on inital size update
        if (_containerShiftIndex !== undefined) {
          var holder, item, hIndex;

          for (var i = 0; i < NUM_HOLDERS; i++) {
            holder = _itemHolders[i];
            _setTranslateX(
              (i + _containerShiftIndex) * _slideSize.x,
              holder.el.style
            );

            hIndex = _currentItemIndex + i - 1;

            if (_options.loop && _getNumItems() > 2) {
              hIndex = _getLoopedId(hIndex);
            }

            // update zoom level on items and refresh source (if needsUpdate)
            item = _getItemAt(hIndex);

            // re-render gallery item if `needsUpdate`,
            // or doesn't have `bounds` (entirely new slide object)
            if (
              item &&
              (_itemsNeedUpdate || item.needsUpdate || !item.bounds)
            ) {
              self.cleanSlide(item);

              self.setContent(holder, hIndex);

              // if "center" slide
              if (i === 1) {
                self.currItem = item;
                self.updateCurrZoomItem(true);
              }

              item.needsUpdate = false;
            } else if (holder.index === -1 && hIndex >= 0) {
              // add content first time
              self.setContent(holder, hIndex);
            }
            if (item && item.container) {
              _calculateItemSize(item, _viewportSize);
              _setImageSize(item);
              _applyZoomPanToItem(item);
            }
          }
          _itemsNeedUpdate = false;
        }

        _startZoomLevel = _currZoomLevel = self.currItem.initialZoomLevel;
        _currPanBounds = self.currItem.bounds;

        if (_currPanBounds) {
          _panOffset.x = _currPanBounds.center.x;
          _panOffset.y = _currPanBounds.center.y;
          _applyCurrentZoomPan(true);
        }

        _shout("resize");
      },

      // Zoom current item to
      zoomTo: function (destZoomLevel, centerPoint, speed, easingFn, updateFn) {
        /*
			if(destZoomLevel === 'fit') {
				destZoomLevel = self.currItem.fitRatio;
			} else if(destZoomLevel === 'fill') {
				destZoomLevel = self.currItem.fillRatio;
			}
		*/

        if (centerPoint) {
          _startZoomLevel = _currZoomLevel;
          _midZoomPoint.x = Math.abs(centerPoint.x) - _panOffset.x;
          _midZoomPoint.y = Math.abs(centerPoint.y) - _panOffset.y;
          _equalizePoints(_startPanOffset, _panOffset);
        }

        var destPanBounds = _calculatePanBounds(destZoomLevel, false),
          destPanOffset = {};

        _modifyDestPanOffset("x", destPanBounds, destPanOffset, destZoomLevel);
        _modifyDestPanOffset("y", destPanBounds, destPanOffset, destZoomLevel);

        var initialZoomLevel = _currZoomLevel;
        var initialPanOffset = {
          x: _panOffset.x,
          y: _panOffset.y,
        };

        _roundPoint(destPanOffset);

        var onUpdate = function (now) {
          if (now === 1) {
            _currZoomLevel = destZoomLevel;
            _panOffset.x = destPanOffset.x;
            _panOffset.y = destPanOffset.y;
          } else {
            _currZoomLevel =
              (destZoomLevel - initialZoomLevel) * now + initialZoomLevel;
            _panOffset.x =
              (destPanOffset.x - initialPanOffset.x) * now + initialPanOffset.x;
            _panOffset.y =
              (destPanOffset.y - initialPanOffset.y) * now + initialPanOffset.y;
          }

          if (updateFn) {updateFn(now);}

          _applyCurrentZoomPan(now === 1);
        };

        if (speed) {
          _animateProp(
            "customZoomTo",
            0,
            1,
            speed,
            easingFn || framework.easing.sine.inOut,
            onUpdate
          );
        } else {onUpdate(1);}
      },
    };

    /*>>core*/

    /*>>gestures*/
    /**
     * Mouse/touch/pointer event handlers.
     *
     * separated from @core.js for readability
     */

    var MIN_SWIPE_DISTANCE = 30,
      DIRECTION_CHECK_OFFSET = 10; // amount of pixels to drag to determine direction of swipe

    var _gestureStartTime,
      _gestureCheckSpeedTime,
      // pool of objects that are used during dragging of zooming
      p = {}, // first point
      p2 = {}, // second point (for zoom gesture)
      delta = {},
      _currPoint = {},
      _startPoint = {},
      _currPointers = [],
      _startMainScrollPos = {},
      _releaseAnimData,
      _posPoints = [], // array of points during dragging, used to determine type of gesture
      _tempPoint = {},
      _isZoomingIn,
      _verticalDragInitiated,
      _oldAndroidTouchEndTimeout,
      _currZoomedItemIndex = 0,
      _centerPoint = _getEmptyPoint(),
      _lastReleaseTime = 0,
      _isDragging, // at least one pointer is down
      _isMultitouch, // at least two _pointers are down
      _zoomStarted, // zoom level changed during zoom gesture
      _moved,
      _dragAnimFrame,
      _mainScrollShifted,
      _currentPoints, // array of current touch points
      _isZooming,
      _currPointsDistance,
      _startPointsDistance,
      _currPanBounds,
      _mainScrollPos = _getEmptyPoint(),
      _currZoomElementStyle,
      _mainScrollAnimating, // true, if animation after swipe gesture is running
      _midZoomPoint = _getEmptyPoint(),
      _currCenterPoint = _getEmptyPoint(),
      _direction,
      _isFirstMove,
      _opacityChanged,
      _bgOpacity,
      _wasOverInitialZoom,
      _isEqualPoints = function (p1, p2) {
        return p1.x === p2.x && p1.y === p2.y;
      },
      _isNearbyPoints = function (touch0, touch1) {
        return (
          Math.abs(touch0.x - touch1.x) < DOUBLE_TAP_RADIUS &&
          Math.abs(touch0.y - touch1.y) < DOUBLE_TAP_RADIUS
        );
      },
      _calculatePointsDistance = function (p1, p2) {
        _tempPoint.x = Math.abs(p1.x - p2.x);
        _tempPoint.y = Math.abs(p1.y - p2.y);
        return Math.sqrt(
          _tempPoint.x * _tempPoint.x + _tempPoint.y * _tempPoint.y
        );
      },
      _stopDragUpdateLoop = function () {
        if (_dragAnimFrame) {
          _cancelAF(_dragAnimFrame);
          _dragAnimFrame = null;
        }
      },
      _dragUpdateLoop = function () {
        if (_isDragging) {
          _dragAnimFrame = _requestAF(_dragUpdateLoop);
          _renderMovement();
        }
      },
      _canPan = function () {
        return !(
          _options.scaleMode === "fit" &&
          _currZoomLevel === self.currItem.initialZoomLevel
        );
      },
      // find the closest parent DOM element
      _closestElement = function (el, fn) {
        if (!el || el === document) {
          return false;
        }

        // don't search elements above pswp__scroll-wrap
        if (
          el.getAttribute("class") &&
          el.getAttribute("class").indexOf("pswp__scroll-wrap") > -1
        ) {
          return false;
        }

        if (fn(el)) {
          return el;
        }

        return _closestElement(el.parentNode, fn);
      },
      _preventObj = {},
      _preventDefaultEventBehaviour = function (e, isDown) {
        _preventObj.prevent = !_closestElement(
          e.target,
          _options.isClickableElement
        );

        _shout("preventDragEvent", e, isDown, _preventObj);
        return _preventObj.prevent;
      },
      _convertTouchToPoint = function (touch, p) {
        p.x = touch.pageX;
        p.y = touch.pageY;
        p.id = touch.identifier;
        return p;
      },
      _findCenterOfPoints = function (p1, p2, pCenter) {
        pCenter.x = (p1.x + p2.x) * 0.5;
        pCenter.y = (p1.y + p2.y) * 0.5;
      },
      _pushPosPoint = function (time, x, y) {
        if (time - _gestureCheckSpeedTime > 50) {
          var o = _posPoints.length > 2 ? _posPoints.shift() : {};
          o.x = x;
          o.y = y;
          _posPoints.push(o);
          _gestureCheckSpeedTime = time;
        }
      },
      _calculateVerticalDragOpacityRatio = function () {
        var yOffset = _panOffset.y - self.currItem.initialPosition.y; // difference between initial and current position
        return 1 - Math.abs(yOffset / (_viewportSize.y / 2));
      },
      // points pool, reused during touch events
      _ePoint1 = {},
      _ePoint2 = {},
      _tempPointsArr = [],
      _tempCounter,
      _getTouchPoints = function (e) {
        // clean up previous points, without recreating array
        while (_tempPointsArr.length > 0) {_tempPointsArr.pop();}

        if (!_pointerEventEnabled) {
          if (e.type.indexOf("touch") > -1) {
            if (e.touches && e.touches.length > 0) {
              _tempPointsArr[0] = _convertTouchToPoint(e.touches[0], _ePoint1);
              if (e.touches.length > 1) {
                _tempPointsArr[1] = _convertTouchToPoint(
                  e.touches[1],
                  _ePoint2
                );
              }
            }
          } else {
            _ePoint1.x = e.pageX;
            _ePoint1.y = e.pageY;
            _ePoint1.id = "";
            _tempPointsArr[0] = _ePoint1; //_ePoint1;
          }
        } else {
          _tempCounter = 0;
          // we can use forEach, as pointer events are supported only in modern browsers
          _currPointers.forEach(function (p) {
            if (_tempCounter === 0) {
              _tempPointsArr[0] = p;
            } else if (_tempCounter === 1) {
              _tempPointsArr[1] = p;
            }
            _tempCounter++;
          });
        }
        return _tempPointsArr;
      },
      _panOrMoveMainScroll = function (axis, delta) {
        var panFriction,
          overDiff = 0,
          newOffset = _panOffset[axis] + delta[axis],
          startOverDiff,
          dir = delta[axis] > 0,
          newMainScrollPosition = _mainScrollPos.x + delta.x,
          mainScrollDiff = _mainScrollPos.x - _startMainScrollPos.x,
          newPanPos,
          newMainScrollPos;

        // calculate fdistance over the bounds and friction
        if (
          newOffset > _currPanBounds.min[axis] ||
          newOffset < _currPanBounds.max[axis]
        ) {
          panFriction = _options.panEndFriction;
          // Linear increasing of friction, so at 1/4 of viewport it's at max value.
          // Looks not as nice as was expected. Left for history.
          // panFriction = (1 - (_panOffset[axis] + delta[axis] + panBounds.min[axis]) / (_viewportSize[axis] / 4) );
        } else {
          panFriction = 1;
        }

        newOffset = _panOffset[axis] + delta[axis] * panFriction;

        // move main scroll or start panning
        if (
          _options.allowPanToNext ||
          _currZoomLevel === self.currItem.initialZoomLevel
        ) {
          if (!_currZoomElementStyle) {
            newMainScrollPos = newMainScrollPosition;
          } else if (_direction === "h" && axis === "x" && !_zoomStarted) {
            if (dir) {
              if (newOffset > _currPanBounds.min[axis]) {
                panFriction = _options.panEndFriction;
                overDiff = _currPanBounds.min[axis] - newOffset;
                startOverDiff =
                  _currPanBounds.min[axis] - _startPanOffset[axis];
              }

              // drag right
              if (
                (startOverDiff <= 0 || mainScrollDiff < 0) &&
                _getNumItems() > 1
              ) {
                newMainScrollPos = newMainScrollPosition;
                if (
                  mainScrollDiff < 0 &&
                  newMainScrollPosition > _startMainScrollPos.x
                ) {
                  newMainScrollPos = _startMainScrollPos.x;
                }
              } else {
                if (_currPanBounds.min.x !== _currPanBounds.max.x) {
                  newPanPos = newOffset;
                }
              }
            } else {
              if (newOffset < _currPanBounds.max[axis]) {
                panFriction = _options.panEndFriction;
                overDiff = newOffset - _currPanBounds.max[axis];
                startOverDiff =
                  _startPanOffset[axis] - _currPanBounds.max[axis];
              }

              if (
                (startOverDiff <= 0 || mainScrollDiff > 0) &&
                _getNumItems() > 1
              ) {
                newMainScrollPos = newMainScrollPosition;

                if (
                  mainScrollDiff > 0 &&
                  newMainScrollPosition < _startMainScrollPos.x
                ) {
                  newMainScrollPos = _startMainScrollPos.x;
                }
              } else {
                if (_currPanBounds.min.x !== _currPanBounds.max.x) {
                  newPanPos = newOffset;
                }
              }
            }

            //
          }

          if (axis === "x") {
            if (newMainScrollPos !== undefined) {
              _moveMainScroll(newMainScrollPos, true);
              if (newMainScrollPos === _startMainScrollPos.x) {
                _mainScrollShifted = false;
              } else {
                _mainScrollShifted = true;
              }
            }

            if (_currPanBounds.min.x !== _currPanBounds.max.x) {
              if (newPanPos !== undefined) {
                _panOffset.x = newPanPos;
              } else if (!_mainScrollShifted) {
                _panOffset.x += delta.x * panFriction;
              }
            }

            return newMainScrollPos !== undefined;
          }
        }

        if (!_mainScrollAnimating) {
          if (!_mainScrollShifted) {
            if (_currZoomLevel > self.currItem.fitRatio) {
              _panOffset[axis] += delta[axis] * panFriction;
            }
          }
        }
      },
      // Pointerdown/touchstart/mousedown handler
      _onDragStart = function (e) {
        // Allow dragging only via left mouse button.
        // As this handler is not added in IE8 - we ignore e.which
        //
        // http://www.quirksmode.org/js/events_properties.html
        // https://developer.mozilla.org/en-US/docs/Web/API/event.button
        if (e.type === "mousedown" && e.button > 0) {return;}

        if (_initialZoomRunning) {
          e.preventDefault();
          return;
        }

        if (_oldAndroidTouchEndTimeout && e.type === "mousedown") {return;}

        if (_preventDefaultEventBehaviour(e, true)) {e.preventDefault();}

        _shout("pointerDown");

        if (_pointerEventEnabled) {
          var pointerIndex = framework.arraySearch(
            _currPointers,
            e.pointerId,
            "id"
          );
          if (pointerIndex < 0) {
            pointerIndex = _currPointers.length;
          }
          _currPointers[pointerIndex] = {
            x: e.pageX,
            y: e.pageY,
            id: e.pointerId,
          };
        }

        var startPointsList = _getTouchPoints(e),
          numPoints = startPointsList.length;

        _currentPoints = null;

        _stopAllAnimations();

        // init drag
        if (!_isDragging || numPoints === 1) {
          _isDragging = _isFirstMove = true;
          framework.bind(window, _upMoveEvents, self);

          _isZoomingIn =
            _wasOverInitialZoom =
            _opacityChanged =
            _verticalDragInitiated =
            _mainScrollShifted =
            _moved =
            _isMultitouch =
            _zoomStarted =
              false;

          _direction = null;

          _shout("firstTouchStart", startPointsList);

          _equalizePoints(_startPanOffset, _panOffset);

          _currPanDist.x = _currPanDist.y = 0;
          _equalizePoints(_currPoint, startPointsList[0]);
          _equalizePoints(_startPoint, _currPoint);

          //_equalizePoints(_startMainScrollPos, _mainScrollPos);
          _startMainScrollPos.x = _slideSize.x * _currPositionIndex;

          _posPoints = [
            {
              x: _currPoint.x,
              y: _currPoint.y,
            },
          ];

          _gestureCheckSpeedTime = _gestureStartTime = _getCurrentTime();

          //_mainScrollAnimationEnd(true);
          _calculatePanBounds(_currZoomLevel, true);

          // Start rendering
          _stopDragUpdateLoop();
          _dragUpdateLoop();
        }

        // init zoom
        if (
          !_isZooming &&
          numPoints > 1 &&
          !_mainScrollAnimating &&
          !_mainScrollShifted
        ) {
          _startZoomLevel = _currZoomLevel;
          _zoomStarted = false; // true if zoom changed at least once

          _isZooming = _isMultitouch = true;
          _currPanDist.y = _currPanDist.x = 0;

          _equalizePoints(_startPanOffset, _panOffset);

          _equalizePoints(p, startPointsList[0]);
          _equalizePoints(p2, startPointsList[1]);

          _findCenterOfPoints(p, p2, _currCenterPoint);

          _midZoomPoint.x = Math.abs(_currCenterPoint.x) - _panOffset.x;
          _midZoomPoint.y = Math.abs(_currCenterPoint.y) - _panOffset.y;
          _currPointsDistance = _startPointsDistance = _calculatePointsDistance(
            p,
            p2
          );
        }
      },
      // Pointermove/touchmove/mousemove handler
      _onDragMove = function (e) {
        e.preventDefault();

        if (_pointerEventEnabled) {
          var pointerIndex = framework.arraySearch(
            _currPointers,
            e.pointerId,
            "id"
          );
          if (pointerIndex > -1) {
            var p = _currPointers[pointerIndex];
            p.x = e.pageX;
            p.y = e.pageY;
          }
        }

        if (_isDragging) {
          var touchesList = _getTouchPoints(e);
          if (!_direction && !_moved && !_isZooming) {
            if (_mainScrollPos.x !== _slideSize.x * _currPositionIndex) {
              // if main scroll position is shifted – direction is always horizontal
              _direction = "h";
            } else {
              var diff =
                Math.abs(touchesList[0].x - _currPoint.x) -
                Math.abs(touchesList[0].y - _currPoint.y);
              // check the direction of movement
              if (Math.abs(diff) >= DIRECTION_CHECK_OFFSET) {
                _direction = diff > 0 ? "h" : "v";
                _currentPoints = touchesList;
              }
            }
          } else {
            _currentPoints = touchesList;
          }
        }
      },
      //
      _renderMovement = function () {
        if (!_currentPoints) {return;}

        var numPoints = _currentPoints.length;

        if (numPoints === 0) {return;}

        _equalizePoints(p, _currentPoints[0]);

        delta.x = p.x - _currPoint.x;
        delta.y = p.y - _currPoint.y;

        if (_isZooming && numPoints > 1) {
          // Handle behaviour for more than 1 point

          _currPoint.x = p.x;
          _currPoint.y = p.y;

          // check if one of two points changed
          if (!delta.x && !delta.y && _isEqualPoints(_currentPoints[1], p2)) {return;}

          _equalizePoints(p2, _currentPoints[1]);

          if (!_zoomStarted) {
            _zoomStarted = true;
            _shout("zoomGestureStarted");
          }

          // Distance between two points
          var pointsDistance = _calculatePointsDistance(p, p2);

          var zoomLevel = _calculateZoomLevel(pointsDistance);

          // slightly over the of initial zoom level
          if (
            zoomLevel >
            self.currItem.initialZoomLevel + self.currItem.initialZoomLevel / 15
          ) {
            _wasOverInitialZoom = true;
          }

          // Apply the friction if zoom level is out of the bounds
          var zoomFriction = 1,
            minZoomLevel = _getMinZoomLevel(),
            maxZoomLevel = _getMaxZoomLevel();

          if (zoomLevel < minZoomLevel) {
            if (
              _options.pinchToClose &&
              !_wasOverInitialZoom &&
              _startZoomLevel <= self.currItem.initialZoomLevel
            ) {
              // fade out background if zooming out
              var minusDiff = minZoomLevel - zoomLevel;
              var percent = 1 - minusDiff / (minZoomLevel / 1.2);

              _applyBgOpacity(percent);
              _shout("onPinchClose", percent);
              _opacityChanged = true;
            } else {
              zoomFriction = (minZoomLevel - zoomLevel) / minZoomLevel;
              if (zoomFriction > 1) {
                zoomFriction = 1;
              }
              zoomLevel = minZoomLevel - zoomFriction * (minZoomLevel / 3);
            }
          } else if (zoomLevel > maxZoomLevel) {
            // 1.5 - extra zoom level above the max. E.g. if max is x6, real max 6 + 1.5 = 7.5
            zoomFriction = (zoomLevel - maxZoomLevel) / (minZoomLevel * 6);
            if (zoomFriction > 1) {
              zoomFriction = 1;
            }
            zoomLevel = maxZoomLevel + zoomFriction * minZoomLevel;
          }

          if (zoomFriction < 0) {
            zoomFriction = 0;
          }

          // distance between touch points after friction is applied
          _currPointsDistance = pointsDistance;

          // _centerPoint - The point in the middle of two pointers
          _findCenterOfPoints(p, p2, _centerPoint);

          // paning with two pointers pressed
          _currPanDist.x += _centerPoint.x - _currCenterPoint.x;
          _currPanDist.y += _centerPoint.y - _currCenterPoint.y;
          _equalizePoints(_currCenterPoint, _centerPoint);

          _panOffset.x = _calculatePanOffset("x", zoomLevel);
          _panOffset.y = _calculatePanOffset("y", zoomLevel);

          _isZoomingIn = zoomLevel > _currZoomLevel;
          _currZoomLevel = zoomLevel;
          _applyCurrentZoomPan();
        } else {
          // handle behaviour for one point (dragging or panning)

          if (!_direction) {return;}

          if (_isFirstMove) {
            _isFirstMove = false;

            // subtract drag distance that was used during the detection direction

            if (Math.abs(delta.x) >= DIRECTION_CHECK_OFFSET) {
              delta.x -= _currentPoints[0].x - _startPoint.x;
            }

            if (Math.abs(delta.y) >= DIRECTION_CHECK_OFFSET) {
              delta.y -= _currentPoints[0].y - _startPoint.y;
            }
          }

          _currPoint.x = p.x;
          _currPoint.y = p.y;

          // do nothing if pointers position hasn't changed
          if (delta.x === 0 && delta.y === 0) {return;}

          if (_direction === "v" && _options.closeOnVerticalDrag) {
            if (!_canPan()) {
              _currPanDist.y += delta.y;
              _panOffset.y += delta.y;

              var opacityRatio = _calculateVerticalDragOpacityRatio();

              _verticalDragInitiated = true;
              _shout("onVerticalDrag", opacityRatio);

              _applyBgOpacity(opacityRatio);
              _applyCurrentZoomPan();
              return;
            }
          }

          _pushPosPoint(_getCurrentTime(), p.x, p.y);

          _moved = true;
          _currPanBounds = self.currItem.bounds;

          var mainScrollChanged = _panOrMoveMainScroll("x", delta);
          if (!mainScrollChanged) {
            _panOrMoveMainScroll("y", delta);

            _roundPoint(_panOffset);
            _applyCurrentZoomPan();
          }
        }
      },
      // Pointerup/pointercancel/touchend/touchcancel/mouseup event handler
      _onDragRelease = function (e) {
        if (_features.isOldAndroid) {
          if (_oldAndroidTouchEndTimeout && e.type === "mouseup") {return;}

          // on Android (v4.1, 4.2, 4.3 & possibly older)
          // ghost mousedown/up event isn't preventable via e.preventDefault,
          // which causes fake mousedown event
          // so we block mousedown/up for 600ms
          if (e.type.indexOf("touch") > -1) {
            clearTimeout(_oldAndroidTouchEndTimeout);
            _oldAndroidTouchEndTimeout = setTimeout(function () {
              _oldAndroidTouchEndTimeout = 0;
            }, 600);
          }
        }

        _shout("pointerUp");

        if (_preventDefaultEventBehaviour(e, false)) {e.preventDefault();}

        var releasePoint;

        if (_pointerEventEnabled) {
          var pointerIndex = framework.arraySearch(
            _currPointers,
            e.pointerId,
            "id"
          );

          if (pointerIndex > -1) {
            releasePoint = _currPointers.splice(pointerIndex, 1)[0];

            if (navigator.msPointerEnabled) {
              var MSPOINTER_TYPES = {
                4: "mouse", // event.MSPOINTER_TYPE_MOUSE
                2: "touch", // event.MSPOINTER_TYPE_TOUCH
                3: "pen", // event.MSPOINTER_TYPE_PEN
              };
              releasePoint.type = MSPOINTER_TYPES[e.pointerType];

              if (!releasePoint.type) {
                releasePoint.type = e.pointerType || "mouse";
              }
            } else {
              releasePoint.type = e.pointerType || "mouse";
            }
          }
        }

        var touchList = _getTouchPoints(e),
          gestureType,
          numPoints = touchList.length;

        if (e.type === "mouseup") {
          numPoints = 0;
        }

        // Do nothing if there were 3 touch points or more
        if (numPoints === 2) {
          _currentPoints = null;
          return true;
        }

        // if second pointer released
        if (numPoints === 1) {
          _equalizePoints(_startPoint, touchList[0]);
        }

        // pointer hasn't moved, send "tap release" point
        if (numPoints === 0 && !_direction && !_mainScrollAnimating) {
          if (!releasePoint) {
            if (e.type === "mouseup") {
              releasePoint = { x: e.pageX, y: e.pageY, type: "mouse" };
            } else if (e.changedTouches && e.changedTouches[0]) {
              releasePoint = {
                x: e.changedTouches[0].pageX,
                y: e.changedTouches[0].pageY,
                type: "touch",
              };
            }
          }

          _shout("touchRelease", e, releasePoint);
        }

        // Difference in time between releasing of two last touch points (zoom gesture)
        var releaseTimeDiff = -1;

        // Gesture completed, no pointers left
        if (numPoints === 0) {
          _isDragging = false;
          framework.unbind(window, _upMoveEvents, self);

          _stopDragUpdateLoop();

          if (_isZooming) {
            // Two points released at the same time
            releaseTimeDiff = 0;
          } else if (_lastReleaseTime !== -1) {
            releaseTimeDiff = _getCurrentTime() - _lastReleaseTime;
          }
        }
        _lastReleaseTime = numPoints === 1 ? _getCurrentTime() : -1;

        if (releaseTimeDiff !== -1 && releaseTimeDiff < 150) {
          gestureType = "zoom";
        } else {
          gestureType = "swipe";
        }

        if (_isZooming && numPoints < 2) {
          _isZooming = false;

          // Only second point released
          if (numPoints === 1) {
            gestureType = "zoomPointerUp";
          }
          _shout("zoomGestureEnded");
        }

        _currentPoints = null;
        if (
          !_moved &&
          !_zoomStarted &&
          !_mainScrollAnimating &&
          !_verticalDragInitiated
        ) {
          // nothing to animate
          return;
        }

        _stopAllAnimations();

        if (!_releaseAnimData) {
          _releaseAnimData = _initDragReleaseAnimationData();
        }

        _releaseAnimData.calculateSwipeSpeed("x");

        if (_verticalDragInitiated) {
          var opacityRatio = _calculateVerticalDragOpacityRatio();

          if (opacityRatio < _options.verticalDragRange) {self.close();} else {
            var initalPanY = _panOffset.y,
              initialBgOpacity = _bgOpacity;

            _animateProp(
              "verticalDrag",
              0,
              1,
              300,
              framework.easing.cubic.out,
              function (now) {
                _panOffset.y =
                  (self.currItem.initialPosition.y - initalPanY) * now +
                  initalPanY;

                _applyBgOpacity(
                  (1 - initialBgOpacity) * now + initialBgOpacity
                );
                _applyCurrentZoomPan();
              }
            );

            _shout("onVerticalDrag", 1);
          }

          return;
        }

        // main scroll
        if ((_mainScrollShifted || _mainScrollAnimating) && numPoints === 0) {
          var itemChanged = _finishSwipeMainScrollGesture(
            gestureType,
            _releaseAnimData
          );
          if (itemChanged) {return;}
          gestureType = "zoomPointerUp";
        }

        // prevent zoom/pan animation when main scroll animation runs
        if (_mainScrollAnimating) {return;}

        // Complete simple zoom gesture (reset zoom level if it's out of the bounds)
        if (gestureType !== "swipe") {
          _completeZoomGesture();
          return;
        }

        // Complete pan gesture if main scroll is not shifted, and it's possible to pan current image
        if (!_mainScrollShifted && _currZoomLevel > self.currItem.fitRatio) {_completePanGesture(_releaseAnimData);}
      },
      // Returns object with data about gesture
      // It's created only once and then reused
      _initDragReleaseAnimationData = function () {
        // temp local vars
        var lastFlickDuration, tempReleasePos;

        // s = this
        var s = {
          lastFlickOffset: {},
          lastFlickDist: {},
          lastFlickSpeed: {},
          slowDownRatio: {},
          slowDownRatioReverse: {},
          speedDecelerationRatio: {},
          speedDecelerationRatioAbs: {},
          distanceOffset: {},
          backAnimDestination: {},
          backAnimStarted: {},
          calculateSwipeSpeed: function (axis) {
            if (_posPoints.length > 1) {
              lastFlickDuration =
                _getCurrentTime() - _gestureCheckSpeedTime + 50;
              tempReleasePos = _posPoints[_posPoints.length - 2][axis];
            } else {
              lastFlickDuration = _getCurrentTime() - _gestureStartTime; // total gesture duration
              tempReleasePos = _startPoint[axis];
            }
            s.lastFlickOffset[axis] = _currPoint[axis] - tempReleasePos;
            s.lastFlickDist[axis] = Math.abs(s.lastFlickOffset[axis]);
            if (s.lastFlickDist[axis] > 20) {
              s.lastFlickSpeed[axis] =
                s.lastFlickOffset[axis] / lastFlickDuration;
            } else {
              s.lastFlickSpeed[axis] = 0;
            }
            if (Math.abs(s.lastFlickSpeed[axis]) < 0.1) {
              s.lastFlickSpeed[axis] = 0;
            }

            s.slowDownRatio[axis] = 0.95;
            s.slowDownRatioReverse[axis] = 1 - s.slowDownRatio[axis];
            s.speedDecelerationRatio[axis] = 1;
          },

          calculateOverBoundsAnimOffset: function (axis, speed) {
            if (!s.backAnimStarted[axis]) {
              if (_panOffset[axis] > _currPanBounds.min[axis]) {
                s.backAnimDestination[axis] = _currPanBounds.min[axis];
              } else if (_panOffset[axis] < _currPanBounds.max[axis]) {
                s.backAnimDestination[axis] = _currPanBounds.max[axis];
              }

              if (s.backAnimDestination[axis] !== undefined) {
                s.slowDownRatio[axis] = 0.7;
                s.slowDownRatioReverse[axis] = 1 - s.slowDownRatio[axis];
                if (s.speedDecelerationRatioAbs[axis] < 0.05) {
                  s.lastFlickSpeed[axis] = 0;
                  s.backAnimStarted[axis] = true;

                  _animateProp(
                    "bounceZoomPan" + axis,
                    _panOffset[axis],
                    s.backAnimDestination[axis],
                    speed || 300,
                    framework.easing.sine.out,
                    function (pos) {
                      _panOffset[axis] = pos;
                      _applyCurrentZoomPan();
                    }
                  );
                }
              }
            }
          },

          // Reduces the speed by slowDownRatio (per 10ms)
          calculateAnimOffset: function (axis) {
            if (!s.backAnimStarted[axis]) {
              s.speedDecelerationRatio[axis] =
                s.speedDecelerationRatio[axis] *
                (s.slowDownRatio[axis] +
                  s.slowDownRatioReverse[axis] -
                  (s.slowDownRatioReverse[axis] * s.timeDiff) / 10);

              s.speedDecelerationRatioAbs[axis] = Math.abs(
                s.lastFlickSpeed[axis] * s.speedDecelerationRatio[axis]
              );
              s.distanceOffset[axis] =
                s.lastFlickSpeed[axis] *
                s.speedDecelerationRatio[axis] *
                s.timeDiff;
              _panOffset[axis] += s.distanceOffset[axis];
            }
          },

          panAnimLoop: function () {
            if (_animations.zoomPan) {
              _animations.zoomPan.raf = _requestAF(s.panAnimLoop);

              s.now = _getCurrentTime();
              s.timeDiff = s.now - s.lastNow;
              s.lastNow = s.now;

              s.calculateAnimOffset("x");
              s.calculateAnimOffset("y");

              _applyCurrentZoomPan();

              s.calculateOverBoundsAnimOffset("x");
              s.calculateOverBoundsAnimOffset("y");

              if (
                s.speedDecelerationRatioAbs.x < 0.05 &&
                s.speedDecelerationRatioAbs.y < 0.05
              ) {
                // round pan position
                _panOffset.x = Math.round(_panOffset.x);
                _panOffset.y = Math.round(_panOffset.y);
                _applyCurrentZoomPan();

                _stopAnimation("zoomPan");
                return;
              }
            }
          },
        };
        return s;
      },
      _completePanGesture = function (animData) {
        // calculate swipe speed for Y axis (paanning)
        animData.calculateSwipeSpeed("y");

        _currPanBounds = self.currItem.bounds;

        animData.backAnimDestination = {};
        animData.backAnimStarted = {};

        // Avoid acceleration animation if speed is too low
        if (
          Math.abs(animData.lastFlickSpeed.x) <= 0.05 &&
          Math.abs(animData.lastFlickSpeed.y) <= 0.05
        ) {
          animData.speedDecelerationRatioAbs.x =
            animData.speedDecelerationRatioAbs.y = 0;

          // Run pan drag release animation. E.g. if you drag image and release finger without momentum.
          animData.calculateOverBoundsAnimOffset("x");
          animData.calculateOverBoundsAnimOffset("y");
          return true;
        }

        // Animation loop that controls the acceleration after pan gesture ends
        _registerStartAnimation("zoomPan");
        animData.lastNow = _getCurrentTime();
        animData.panAnimLoop();
      },
      _finishSwipeMainScrollGesture = function (gestureType, _releaseAnimData) {
        var itemChanged;
        if (!_mainScrollAnimating) {
          _currZoomedItemIndex = _currentItemIndex;
        }

        var itemsDiff;

        if (gestureType === "swipe") {
          var totalShiftDist = _currPoint.x - _startPoint.x,
            isFastLastFlick = _releaseAnimData.lastFlickDist.x < 10;

          // if container is shifted for more than MIN_SWIPE_DISTANCE,
          // and last flick gesture was in right direction
          if (
            totalShiftDist > MIN_SWIPE_DISTANCE &&
            (isFastLastFlick || _releaseAnimData.lastFlickOffset.x > 20)
          ) {
            // go to prev item
            itemsDiff = -1;
          } else if (
            totalShiftDist < -MIN_SWIPE_DISTANCE &&
            (isFastLastFlick || _releaseAnimData.lastFlickOffset.x < -20)
          ) {
            // go to next item
            itemsDiff = 1;
          }
        }

        var nextCircle;

        if (itemsDiff) {
          _currentItemIndex += itemsDiff;

          if (_currentItemIndex < 0) {
            _currentItemIndex = _options.loop ? _getNumItems() - 1 : 0;
            nextCircle = true;
          } else if (_currentItemIndex >= _getNumItems()) {
            _currentItemIndex = _options.loop ? 0 : _getNumItems() - 1;
            nextCircle = true;
          }

          if (!nextCircle || _options.loop) {
            _indexDiff += itemsDiff;
            _currPositionIndex -= itemsDiff;
            itemChanged = true;
          }
        }

        var animateToX = _slideSize.x * _currPositionIndex;
        var animateToDist = Math.abs(animateToX - _mainScrollPos.x);
        var finishAnimDuration;

        if (
          !itemChanged &&
          animateToX > _mainScrollPos.x !==
            _releaseAnimData.lastFlickSpeed.x > 0
        ) {
          // "return to current" duration, e.g. when dragging from slide 0 to -1
          finishAnimDuration = 333;
        } else {
          finishAnimDuration =
            Math.abs(_releaseAnimData.lastFlickSpeed.x) > 0
              ? animateToDist / Math.abs(_releaseAnimData.lastFlickSpeed.x)
              : 333;

          finishAnimDuration = Math.min(finishAnimDuration, 400);
          finishAnimDuration = Math.max(finishAnimDuration, 250);
        }

        if (_currZoomedItemIndex === _currentItemIndex) {
          itemChanged = false;
        }

        _mainScrollAnimating = true;

        _shout("mainScrollAnimStart");

        _animateProp(
          "mainScroll",
          _mainScrollPos.x,
          animateToX,
          finishAnimDuration,
          framework.easing.cubic.out,
          _moveMainScroll,
          function () {
            _stopAllAnimations();
            _mainScrollAnimating = false;
            _currZoomedItemIndex = -1;

            if (itemChanged || _currZoomedItemIndex !== _currentItemIndex) {self.updateCurrItem();}

            _shout("mainScrollAnimComplete");
          }
        );

        if (itemChanged) {self.updateCurrItem(true);}

        return itemChanged;
      },
      _calculateZoomLevel = function (touchesDistance) {
        return (1 / _startPointsDistance) * touchesDistance * _startZoomLevel;
      },
      // Resets zoom if it's out of bounds
      _completeZoomGesture = function () {
        var destZoomLevel = _currZoomLevel,
          minZoomLevel = _getMinZoomLevel(),
          maxZoomLevel = _getMaxZoomLevel();

        if (_currZoomLevel < minZoomLevel) {
          destZoomLevel = minZoomLevel;
        } else if (_currZoomLevel > maxZoomLevel) {
          destZoomLevel = maxZoomLevel;
        }

        var destOpacity = 1,
          onUpdate,
          initialOpacity = _bgOpacity;

        if (
          _opacityChanged &&
          !_isZoomingIn &&
          !_wasOverInitialZoom &&
          _currZoomLevel < minZoomLevel
        ) {
          //_closedByScroll = true;
          self.close();
          return true;
        }

        if (_opacityChanged) {
          onUpdate = function (now) {
            _applyBgOpacity(
              (destOpacity - initialOpacity) * now + initialOpacity
            );
          };
        }

        self.zoomTo(
          destZoomLevel,
          0,
          200,
          framework.easing.cubic.out,
          onUpdate
        );
        return true;
      };

    _registerModule("Gestures", {
      publicMethods: {
        initGestures: function () {
          // helper function that builds touch/pointer/mouse events
          var addEventNames = function (pref, down, move, up, cancel) {
            _dragStartEvent = pref + down;
            _dragMoveEvent = pref + move;
            _dragEndEvent = pref + up;
            if (cancel) {
              _dragCancelEvent = pref + cancel;
            } else {
              _dragCancelEvent = "";
            }
          };

          _pointerEventEnabled = _features.pointerEvent;
          if (_pointerEventEnabled && _features.touch) {
            // we don't need touch events, if browser supports pointer events
            _features.touch = false;
          }

          if (_pointerEventEnabled) {
            if (navigator.msPointerEnabled) {
              // IE10 pointer events are case-sensitive
              addEventNames("MSPointer", "Down", "Move", "Up", "Cancel");
            } else {
              addEventNames("pointer", "down", "move", "up", "cancel");
            }
          } else if (_features.touch) {
            addEventNames("touch", "start", "move", "end", "cancel");
            _likelyTouchDevice = true;
          } else {
            addEventNames("mouse", "down", "move", "up");
          }

          _upMoveEvents =
            _dragMoveEvent + " " + _dragEndEvent + " " + _dragCancelEvent;
          _downEvents = _dragStartEvent;

          if (_pointerEventEnabled && !_likelyTouchDevice) {
            _likelyTouchDevice =
              navigator.maxTouchPoints > 1 || navigator.msMaxTouchPoints > 1;
          }
          // make variable public
          self.likelyTouchDevice = _likelyTouchDevice;

          _globalEventHandlers[_dragStartEvent] = _onDragStart;
          _globalEventHandlers[_dragMoveEvent] = _onDragMove;
          _globalEventHandlers[_dragEndEvent] = _onDragRelease; // the Kraken

          if (_dragCancelEvent) {
            _globalEventHandlers[_dragCancelEvent] =
              _globalEventHandlers[_dragEndEvent];
          }

          // Bind mouse events on device with detected hardware touch support, in case it supports multiple types of input.
          if (_features.touch) {
            _downEvents += " mousedown";
            _upMoveEvents += " mousemove mouseup";
            _globalEventHandlers.mousedown =
              _globalEventHandlers[_dragStartEvent];
            _globalEventHandlers.mousemove =
              _globalEventHandlers[_dragMoveEvent];
            _globalEventHandlers.mouseup = _globalEventHandlers[_dragEndEvent];
          }

          if (!_likelyTouchDevice) {
            // don't allow pan to next slide from zoomed state on Desktop
            _options.allowPanToNext = false;
          }
        },
      },
    });

    /*>>gestures*/

    /*>>show-hide-transition*/
    /**
     * show-hide-transition.js:
     *
     * Manages initial opening or closing transition.
     *
     * If you're not planning to use transition for gallery at all,
     * you may set options hideAnimationDuration and showAnimationDuration to 0,
     * and just delete startAnimation function.
     *
     */

    var _showOrHideTimeout,
      _showOrHide = function (item, img, out, completeFn) {
        if (_showOrHideTimeout) {clearTimeout(_showOrHideTimeout);}

        _initialZoomRunning = true;
        _initialContentSet = true;

        // dimensions of small thumbnail {x:,y:,w:}.
        // Height is optional, as calculated based on large image.
        var thumbBounds;
        if (item.initialLayout) {
          thumbBounds = item.initialLayout;
          item.initialLayout = null;
        } else {
          thumbBounds =
            _options.getThumbBoundsFn &&
            _options.getThumbBoundsFn(_currentItemIndex);
        }

        var duration = out
          ? _options.hideAnimationDuration
          : _options.showAnimationDuration;

        var onComplete = function () {
          _stopAnimation("initialZoom");
          if (!out) {
            _applyBgOpacity(1);
            if (img) {
              img.style.display = "block";
            }
            framework.addClass(template, "pswp--animated-in");
            _shout("initialZoom" + (out ? "OutEnd" : "InEnd"));
          } else {
            self.template.removeAttribute("style");
            self.bg.removeAttribute("style");
          }

          if (completeFn) {completeFn();}
          _initialZoomRunning = false;
        };

        // if bounds aren't provided, just open gallery without animation
        if (!duration || !thumbBounds || thumbBounds.x === undefined) {
          _shout("initialZoom" + (out ? "Out" : "In"));

          _currZoomLevel = item.initialZoomLevel;
          _equalizePoints(_panOffset, item.initialPosition);
          _applyCurrentZoomPan();

          template.style.opacity = out ? 0 : 1;
          _applyBgOpacity(1);

          if (duration) {
            setTimeout(function () {onComplete();}, duration);
          } else {onComplete();}

          return;
        }

        var startAnimation = function () {
          var closeWithRaf = _closedByScroll,
            fadeEverything =
              !self.currItem.src ||
              self.currItem.loadError ||
              _options.showHideOpacity;

          // apply hw-acceleration to image
          if (item.miniImg) {
            item.miniImg.style.webkitBackfaceVisibility = "hidden";
          }

          if (!out) {
            _currZoomLevel = thumbBounds.w / item.w;
            _panOffset.x = thumbBounds.x;
            _panOffset.y = thumbBounds.y - _initalWindowScrollY;

            self[fadeEverything ? "template" : "bg"].style.opacity = 0.001;
            _applyCurrentZoomPan();
          }

          _registerStartAnimation("initialZoom");

          if (out && !closeWithRaf) {
            framework.removeClass(template, "pswp--animated-in");
          }

          if (fadeEverything) {
            if (out) {
              framework[(closeWithRaf ? "remove" : "add") + "Class"](
                template,
                "pswp--animate_opacity"
              );
            } else {
              setTimeout(function () {
                framework.addClass(template, "pswp--animate_opacity");
              }, 30);
            }
          }

          _showOrHideTimeout = setTimeout(
            function () {
              _shout("initialZoom" + (out ? "Out" : "In"));

              if (!out) {
                // "in" animation always uses CSS transitions (instead of rAF).
                // CSS transition work faster here,
                // as developer may also want to animate other things,
                // like ui on top of sliding area, which can be animated just via CSS

                _currZoomLevel = item.initialZoomLevel;
                _equalizePoints(_panOffset, item.initialPosition);
                _applyCurrentZoomPan();
                _applyBgOpacity(1);

                if (fadeEverything) {
                  template.style.opacity = 1;
                } else {_applyBgOpacity(1);}

                _showOrHideTimeout = setTimeout(onComplete, duration + 20);
              } else {
                // "out" animation uses rAF only when PhotoSwipe is closed by browser scroll, to recalculate position
                var destZoomLevel = thumbBounds.w / item.w,
                  initialPanOffset = {
                    x: _panOffset.x,
                    y: _panOffset.y,
                  },
                  initialZoomLevel = _currZoomLevel,
                  initalBgOpacity = _bgOpacity,
                  onUpdate = function (now) {
                    if (now === 1) {
                      _currZoomLevel = destZoomLevel;
                      _panOffset.x = thumbBounds.x;
                      _panOffset.y = thumbBounds.y - _currentWindowScrollY;
                    } else {
                      _currZoomLevel =
                        (destZoomLevel - initialZoomLevel) * now +
                        initialZoomLevel;
                      _panOffset.x =
                        (thumbBounds.x - initialPanOffset.x) * now +
                        initialPanOffset.x;
                      _panOffset.y =
                        (thumbBounds.y -
                          _currentWindowScrollY -
                          initialPanOffset.y) *
                          now +
                        initialPanOffset.y;
                    }

                    _applyCurrentZoomPan();
                    if (fadeEverything) {
                      template.style.opacity = 1 - now;
                    } else {
                      _applyBgOpacity(initalBgOpacity - now * initalBgOpacity);
                    }
                  };

                if (closeWithRaf) {
                  _animateProp(
                    "initialZoom",
                    0,
                    1,
                    duration,
                    framework.easing.cubic.out,
                    onUpdate,
                    onComplete
                  );
                } else {
                  onUpdate(1);
                  _showOrHideTimeout = setTimeout(onComplete, duration + 20);
                }
              }
            },
            out ? 25 : 90
          ); // Main purpose of this delay is to give browser time to paint and
          // create composite layers of PhotoSwipe UI parts (background, controls, caption, arrows).
          // Which avoids lag at the beginning of scale transition.
        };
        startAnimation();
      };

    /*>>show-hide-transition*/

    /*>>items-controller*/
    /**
     *
     * Controller manages gallery items, their dimensions, and their content.
     *
     */

    var _items,
      _tempPanAreaSize = {},
      _imagesToAppendPool = [],
      _initialContentSet,
      _initialZoomRunning,
      _controllerDefaultOptions = {
        index: 0,
        errorMsg:
          '<div class="pswp__error-msg"><a href="%url%" target="_blank">The image</a> could not be loaded.</div>',
        forceProgressiveLoading: false, // TODO
        preload: [1, 1],
        getNumItemsFn: function () {
          return _items.length;
        },
      };

    var _getItemAt,
      _getNumItems,
      _initialIsLoop,
      _getZeroBounds = function () {
        return {
          center: { x: 0, y: 0 },
          max: { x: 0, y: 0 },
          min: { x: 0, y: 0 },
        };
      },
      _calculateSingleItemPanBounds = function (
        item,
        realPanElementW,
        realPanElementH
      ) {
        var bounds = item.bounds;

        // position of element when it's centered
        bounds.center.x = Math.round(
          (_tempPanAreaSize.x - realPanElementW) / 2
        );
        bounds.center.y =
          Math.round((_tempPanAreaSize.y - realPanElementH) / 2) +
          item.vGap.top;

        // maximum pan position
        bounds.max.x =
          realPanElementW > _tempPanAreaSize.x
            ? Math.round(_tempPanAreaSize.x - realPanElementW)
            : bounds.center.x;

        bounds.max.y =
          realPanElementH > _tempPanAreaSize.y
            ? Math.round(_tempPanAreaSize.y - realPanElementH) + item.vGap.top
            : bounds.center.y;

        // minimum pan position
        bounds.min.x =
          realPanElementW > _tempPanAreaSize.x ? 0 : bounds.center.x;
        bounds.min.y =
          realPanElementH > _tempPanAreaSize.y
            ? item.vGap.top
            : bounds.center.y;
      },
      _calculateItemSize = function (item, viewportSize, zoomLevel) {
        if (item.src && !item.loadError) {
          var isInitial = !zoomLevel;

          if (isInitial) {
            if (!item.vGap) {
              item.vGap = { top: 0, bottom: 0 };
            }
            // allows overriding vertical margin for individual items
            _shout("parseVerticalMargin", item);
          }

          _tempPanAreaSize.x = viewportSize.x;
          _tempPanAreaSize.y =
            viewportSize.y - item.vGap.top - item.vGap.bottom;

          if (isInitial) {
            var hRatio = _tempPanAreaSize.x / item.w;
            var vRatio = _tempPanAreaSize.y / item.h;

            item.fitRatio = hRatio < vRatio ? hRatio : vRatio;
            //item.fillRatio = hRatio > vRatio ? hRatio : vRatio;

            var scaleMode = _options.scaleMode;

            if (scaleMode === "orig") {
              zoomLevel = 1;
            } else if (scaleMode === "fit") {
              zoomLevel = item.fitRatio;
            }

            if (zoomLevel > 1) {
              zoomLevel = 1;
            }

            item.initialZoomLevel = zoomLevel;

            if (!item.bounds) {
              // reuse bounds object
              item.bounds = _getZeroBounds();
            }
          }

          if (!zoomLevel) {return;}

          _calculateSingleItemPanBounds(
            item,
            item.w * zoomLevel,
            item.h * zoomLevel
          );

          if (isInitial && zoomLevel === item.initialZoomLevel) {
            item.initialPosition = item.bounds.center;
          }

          return item.bounds;
        } else {
          item.w = item.h = 0;
          item.initialZoomLevel = item.fitRatio = 1;
          item.bounds = _getZeroBounds();
          item.initialPosition = item.bounds.center;

          // if it's not image, we return zero bounds (content is not zoomable)
          return item.bounds;
        }
      },
      _appendImage = function (
        index,
        item,
        baseDiv,
        img,
        preventAnimation,
        keepPlaceholder
      ) {
        if (item.loadError) {return;}

        if (img) {
          item.imageAppended = true;
          _setImageSize(
            item,
            img,
            item === self.currItem && _renderMaxResolution
          );

          baseDiv.appendChild(img);

          if (keepPlaceholder) {
            setTimeout(function () {
              if (item && item.loaded && item.placeholder) {
                item.placeholder.style.display = "none";
                item.placeholder = null;
              }
            }, 500);
          }
        }
      },
      _preloadImage = function (item) {
        item.loading = true;
        item.loaded = false;
        var img = (item.img = framework.createEl("pswp__img", "img"));
        var onComplete = function () {
          item.loading = false;
          item.loaded = true;

          if (item.loadComplete) {item.loadComplete(item);} else {
            item.img = null; // no need to store image object
          }
          img.onload = img.onerror = null;
          img = null;
        };
        img.onload = onComplete;
        img.onerror = function () {
          item.loadError = true;
          onComplete();
        };

        img.src = item.src; // + '?a=' + Math.random();

        return img;
      },
      _checkForError = function (item, cleanUp) {
        if (item.src && item.loadError && item.container) {
          if (cleanUp) {
            item.container.innerHTML = "";
          }

          item.container.innerHTML = _options.errorMsg.replace(
            "%url%",
            item.src
          );
          return true;
        }
      },
      _setImageSize = function (item, img, maxRes) {
        if (!item.src) {return;}

        if (!img) {
          img = item.container.lastChild;
        }

        var w = maxRes ? item.w : Math.round(item.w * item.fitRatio),
          h = maxRes ? item.h : Math.round(item.h * item.fitRatio);

        if (item.placeholder && !item.loaded) {
          item.placeholder.style.width = w + "px";
          item.placeholder.style.height = h + "px";
        }

        img.style.width = w + "px";
        img.style.height = h + "px";
      },
      _appendImagesPool = function () {
        if (_imagesToAppendPool.length) {
          var poolItem;

          for (var i = 0; i < _imagesToAppendPool.length; i++) {
            poolItem = _imagesToAppendPool[i];
            if (poolItem.holder.index === poolItem.index) {
              _appendImage(
                poolItem.index,
                poolItem.item,
                poolItem.baseDiv,
                poolItem.img,
                false,
                poolItem.clearPlaceholder
              );
            }
          }
          _imagesToAppendPool = [];
        }
      };

    _registerModule("Controller", {
      publicMethods: {
        lazyLoadItem: function (index) {
          index = _getLoopedId(index);
          var item = _getItemAt(index);

          if (!item || ((item.loaded || item.loading) && !_itemsNeedUpdate)) {return;}

          _shout("gettingData", index, item);

          if (!item.src) {return;}

          _preloadImage(item);
        },
        initController: function () {
          framework.extend(_options, _controllerDefaultOptions, true);
          self.items = _items = items;
          _getItemAt = self.getItemAt;
          _getNumItems = _options.getNumItemsFn; //self.getNumItems;

          _initialIsLoop = _options.loop;
          if (_getNumItems() < 3) {
            _options.loop = false; // disable loop if less then 3 items
          }

          _listen("beforeChange", function (diff) {
            var p = _options.preload,
              isNext = diff === null ? true : diff >= 0,
              preloadBefore = Math.min(p[0], _getNumItems()),
              preloadAfter = Math.min(p[1], _getNumItems()),
              i;

            for (i = 1; i <= (isNext ? preloadAfter : preloadBefore); i++) {
              self.lazyLoadItem(_currentItemIndex + i);
            }
            for (i = 1; i <= (isNext ? preloadBefore : preloadAfter); i++) {
              self.lazyLoadItem(_currentItemIndex - i);
            }
          });

          _listen("initialLayout", function () {
            self.currItem.initialLayout =
              _options.getThumbBoundsFn &&
              _options.getThumbBoundsFn(_currentItemIndex);
          });

          _listen("mainScrollAnimComplete", _appendImagesPool);
          _listen("initialZoomInEnd", _appendImagesPool);

          _listen("destroy", function () {
            var item;
            for (var i = 0; i < _items.length; i++) {
              item = _items[i];
              // remove reference to DOM elements, for GC
              if (item.container) {
                item.container = null;
              }
              if (item.placeholder) {
                item.placeholder = null;
              }
              if (item.img) {
                item.img = null;
              }
              if (item.preloader) {
                item.preloader = null;
              }
              if (item.loadError) {
                item.loaded = item.loadError = false;
              }
            }
            _imagesToAppendPool = null;
          });
        },

        getItemAt: function (index) {
          if (index >= 0) {
            return _items[index] !== undefined ? _items[index] : false;
          }
          return false;
        },

        allowProgressiveImg: function () {
          // 1. Progressive image loading isn't working on webkit/blink
          //    when hw-acceleration (e.g. translateZ) is applied to IMG element.
          //    That's why in PhotoSwipe parent element gets zoom transform, not image itself.
          //
          // 2. Progressive image loading sometimes blinks in webkit/blink when applying animation to parent element.
          //    That's why it's disabled on touch devices (mainly because of swipe transition)
          //
          // 3. Progressive image loading sometimes doesn't work in IE (up to 11).

          // Don't allow progressive loading on non-large touch devices
          return (
            _options.forceProgressiveLoading ||
            !_likelyTouchDevice ||
            _options.mouseUsed ||
            screen.width > 1200
          );
          // 1200 - to eliminate touch devices with large screen (like Chromebook Pixel)
        },

        setContent: function (holder, index) {
          if (_options.loop) {
            index = _getLoopedId(index);
          }

          var prevItem = self.getItemAt(holder.index);
          if (prevItem) {
            prevItem.container = null;
          }

          var item = self.getItemAt(index),
            img;

          if (!item) {
            holder.el.innerHTML = "";
            return;
          }

          // allow to override data
          _shout("gettingData", index, item);

          holder.index = index;
          holder.item = item;

          // base container DIV is created only once for each of 3 holders
          var baseDiv = (item.container =
            framework.createEl("pswp__zoom-wrap"));

          if (!item.src && item.html) {
            if (item.html.tagName) {baseDiv.appendChild(item.html);} else {
              baseDiv.innerHTML = item.html;
            }
          }

          _checkForError(item);

          _calculateItemSize(item, _viewportSize);

          if (item.src && !item.loadError && !item.loaded) {
            item.loadComplete = function (item) {
              // gallery closed before image finished loading
              if (!_isOpen) {return;}

              // check if holder hasn't changed while image was loading
              if (holder && holder.index === index) {
                if (_checkForError(item, true)) {
                  item.loadComplete = item.img = null;
                  _calculateItemSize(item, _viewportSize);
                  _applyZoomPanToItem(item);

                  if (holder.index === _currentItemIndex) {
                    // recalculate dimensions
                    self.updateCurrZoomItem();
                  }
                  return;
                }
                if (!item.imageAppended) {
                  if (
                    _features.transform &&
                    (_mainScrollAnimating || _initialZoomRunning)
                  ) {
                    _imagesToAppendPool.push({
                      item: item,
                      baseDiv: baseDiv,
                      img: item.img,
                      index: index,
                      holder: holder,
                      clearPlaceholder: true,
                    });
                  } else {
                    _appendImage(
                      index,
                      item,
                      baseDiv,
                      item.img,
                      _mainScrollAnimating || _initialZoomRunning,
                      true
                    );
                  }
                } else {
                  // remove preloader & mini-img
                  if (!_initialZoomRunning && item.placeholder) {
                    item.placeholder.style.display = "none";
                    item.placeholder = null;
                  }
                }
              }

              item.loadComplete = null;
              item.img = null; // no need to store image element after it's added

              _shout("imageLoadComplete", index, item);
            };

            if (framework.features.transform) {
              var placeholderClassName = "pswp__img pswp__img--placeholder";
              placeholderClassName += item.msrc
                ? ""
                : " pswp__img--placeholder--blank";

              var placeholder = framework.createEl(
                placeholderClassName,
                item.msrc ? "img" : ""
              );
              if (item.msrc) {
                placeholder.src = item.msrc;
              }

              _setImageSize(item, placeholder);

              baseDiv.appendChild(placeholder);
              item.placeholder = placeholder;
            }

            if (!item.loading) {_preloadImage(item);}

            if (self.allowProgressiveImg()) {
              // just append image
              if (!_initialContentSet && _features.transform) {
                _imagesToAppendPool.push({
                  item: item,
                  baseDiv: baseDiv,
                  img: item.img,
                  index: index,
                  holder: holder,
                });
              } else {
                _appendImage(index, item, baseDiv, item.img, true, true);
              }
            }
          } else if (item.src && !item.loadError) {
            // image object is created every time, due to bugs of image loading & delay when switching images
            img = framework.createEl("pswp__img", "img");
            img.style.opacity = 1;
            img.src = item.src;
            _setImageSize(item, img);
            _appendImage(index, item, baseDiv, img, true);
          }

          if (!_initialContentSet && index === _currentItemIndex) {
            _currZoomElementStyle = baseDiv.style;
            _showOrHide(item, img || item.img);
          } else {_applyZoomPanToItem(item);}

          holder.el.innerHTML = "";
          holder.el.appendChild(baseDiv);
        },

        cleanSlide: function (item) {
          if (item.img) {
            item.img.onload = item.img.onerror = null;
          }
          item.loaded = item.loading = item.img = item.imageAppended = false;
        },
      },
    });

    /*>>items-controller*/

    /*>>tap*/
    /**
     * tap.js:
     *
     * Displatches tap and double-tap events.
     *
     */

    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);
      };

    _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;
          }
        },
        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);
          }
        },
      },
    });

    /*>>tap*/

    /*>>desktop-zoom*/
    /**
     *
     * desktop-zoom.js:
     *
     * - Binds mousewheel event for paning zoomed image.
     * - Manages "dragging", "zoomed-in", "zoom-out" classes.
     *   (which are used for cursors and zoom icon)
     * - Adds toggleDesktopZoom function.
     *
     */

    var _wheelDelta;

    _registerModule("DesktopZoom", {
      publicMethods: {
        initDesktopZoom: function () {
          if (_oldIE) {
            // no zoom for old IE (<=8)
            return;
          }

          if (_likelyTouchDevice) {
            // if detected hardware touch support, we wait until mouse is used,
            // and only then apply desktop-zoom features
            _listen("mouseUsed", function () {self.setupDesktopZoom();});
          } else {self.setupDesktopZoom(true);}
        },

        setupDesktopZoom: function (onInit) {
          _wheelDelta = {};

          var events = "wheel mousewheel DOMMouseScroll";

          _listen("bindEvents", function () {
            framework.bind(template, events, self.handleMouseWheel);
          });

          _listen("unbindEvents", function () {
            if (_wheelDelta) {
              framework.unbind(template, events, self.handleMouseWheel);
            }
          });

          self.mouseZoomedIn = false;

          var hasDraggingClass,
            updateZoomable = function () {
              if (self.mouseZoomedIn) {
                framework.removeClass(template, "pswp--zoomed-in");
                self.mouseZoomedIn = false;
              }
              if (_currZoomLevel < 1) {
                framework.addClass(template, "pswp--zoom-allowed");
              } else {
                framework.removeClass(template, "pswp--zoom-allowed");
              }
              removeDraggingClass();
            },
            removeDraggingClass = function () {
              if (hasDraggingClass) {
                framework.removeClass(template, "pswp--dragging");
                hasDraggingClass = false;
              }
            };

          _listen("resize", updateZoomable);
          _listen("afterChange", updateZoomable);
          _listen("pointerDown", function () {
            if (self.mouseZoomedIn) {
              hasDraggingClass = true;
              framework.addClass(template, "pswp--dragging");
            }
          });
          _listen("pointerUp", removeDraggingClass);

          if (!onInit) {updateZoomable();}
        },

        handleMouseWheel: function (e) {
          if (_currZoomLevel <= self.currItem.fitRatio) {
            if (_options.modal) {
              if (!_options.closeOnScroll || _numAnimations || _isDragging) {e.preventDefault();} else if (_transformKey && Math.abs(e.deltaY) > 2) {
                // close PhotoSwipe
                // if browser supports transforms & scroll changed enough
                _closedByScroll = true;
                self.close();
              }
            }
            return true;
          }

          // allow just one event to fire
          e.stopPropagation();

          // https://developer.mozilla.org/en-US/docs/Web/Events/wheel
          _wheelDelta.x = 0;

          if ("deltaX" in e) {
            if (e.deltaMode === 1 /* DOM_DELTA_LINE */) {
              // 18 - average line height
              _wheelDelta.x = e.deltaX * 18;
              _wheelDelta.y = e.deltaY * 18;
            } else {
              _wheelDelta.x = e.deltaX;
              _wheelDelta.y = e.deltaY;
            }
          } else if ("wheelDelta" in e) {
            if (e.wheelDeltaX) {
              _wheelDelta.x = -0.16 * e.wheelDeltaX;
            }
            if (e.wheelDeltaY) {
              _wheelDelta.y = -0.16 * e.wheelDeltaY;
            } else {
              _wheelDelta.y = -0.16 * e.wheelDelta;
            }
          } else if ("detail" in e) {
            _wheelDelta.y = e.detail;
          } else {return;}

          _calculatePanBounds(_currZoomLevel, true);

          var newPanX = _panOffset.x - _wheelDelta.x,
            newPanY = _panOffset.y - _wheelDelta.y;

          // only prevent scrolling in nonmodal mode when not at edges
          if (
            _options.modal ||
            (newPanX <= _currPanBounds.min.x &&
              newPanX >= _currPanBounds.max.x &&
              newPanY <= _currPanBounds.min.y &&
              newPanY >= _currPanBounds.max.y)
          ) {e.preventDefault();}

          // TODO: use rAF instead of mousewheel?
          self.panTo(newPanX, newPanY);
        },

        toggleDesktopZoom: function (centerPoint) {
          centerPoint = centerPoint || {
            x: _viewportSize.x / 2 + _offset.x,
            y: _viewportSize.y / 2 + _offset.y,
          };

          var doubleTapZoomLevel = _options.getDoubleTapZoom(
            true,
            self.currItem
          );
          var zoomOut = _currZoomLevel === doubleTapZoomLevel;

          self.mouseZoomedIn = !zoomOut;

          self.zoomTo(
            zoomOut ? self.currItem.initialZoomLevel : doubleTapZoomLevel,
            centerPoint,
            333
          );
          framework[(!zoomOut ? "add" : "remove") + "Class"](
            template,
            "pswp--zoomed-in"
          );
        },
      },
    });

    /*>>desktop-zoom*/

    /*>>history*/
    /**
     *
     * history.js:
     *
     * - Back button to close gallery.
     *
     * - Unique URL for each slide: example.com/&pid=1&gid=3
     *   (where PID is picture index, and GID and gallery index)
     *
     * - Switch URL when slides change.
     *
     */

    var _historyDefaultOptions = {
      history: true,
      galleryUID: 1,
    };

    var _historyUpdateTimeout,
      _hashChangeTimeout,
      _hashAnimCheckTimeout,
      _hashChangedByScript,
      _hashChangedByHistory,
      _hashReseted,
      _initialHash,
      _historyChanged,
      _closedFromURL,
      _urlChangedOnce,
      _windowLoc,
      _supportsPushState,
      _getHash = function () {
        return _windowLoc.hash.substring(1);
      },
      _cleanHistoryTimeouts = function () {
        if (_historyUpdateTimeout) {clearTimeout(_historyUpdateTimeout);}

        if (_hashAnimCheckTimeout) {clearTimeout(_hashAnimCheckTimeout);}
      },
      // pid - Picture index
      // gid - Gallery index
      _parseItemIndexFromURL = function () {
        var hash = _getHash(),
          params = {};

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

        var i,
          vars = hash.split("&");
        for (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 (_options.galleryPIDs) {
          // detect custom pid in hash and search for it among the items collection
          var searchfor = params.pid;
          params.pid = 0; // if custom pid cannot be found, fallback to the first item
          for (i = 0; i < _items.length; i++) {
            if (_items[i].pid === searchfor) {
              params.pid = i;
              break;
            }
          }
        } else {
          params.pid = parseInt(params.pid, 10) - 1;
        }
        if (params.pid < 0) {
          params.pid = 0;
        }
        return params;
      },
      _updateHash = function () {
        if (_hashAnimCheckTimeout) {clearTimeout(_hashAnimCheckTimeout);}

        if (_numAnimations || _isDragging) {
          // changing browser URL forces layout/paint in some browsers, which causes noticable lag during animation
          // that's why we update hash only when no animations running
          _hashAnimCheckTimeout = setTimeout(_updateHash, 500);
          return;
        }

        if (_hashChangedByScript) {clearTimeout(_hashChangeTimeout);} else {
          _hashChangedByScript = true;
        }

        var pid = _currentItemIndex + 1;
        var item = _getItemAt(_currentItemIndex);
        if (item.hasOwnProperty("pid")) {
          // carry forward any custom pid assigned to the item
          pid = item.pid;
        }
        var newHash =
          _initialHash +
          "&" +
          "gid=" +
          _options.galleryUID +
          "&" +
          "pid=" +
          pid;

        if (!_historyChanged) {
          if (_windowLoc.hash.indexOf(newHash) === -1) {
            _urlChangedOnce = true;
          }
          // first time - add new hisory record, then just replace
        }

        var newURL = _windowLoc.href.split("#")[0] + "#" + newHash;

        if (_supportsPushState) {
          if ("#" + newHash !== window.location.hash) {
            history[_historyChanged ? "replaceState" : "pushState"](
              "",
              document.title,
              newURL
            );
          }
        } else {
          if (_historyChanged) {_windowLoc.replace(newURL);} else {
            _windowLoc.hash = newHash;
          }
        }

        _historyChanged = true;
        _hashChangeTimeout = setTimeout(function () {
          _hashChangedByScript = false;
        }, 60);
      };

    _registerModule("History", {
      publicMethods: {
        initHistory: function () {
          framework.extend(_options, _historyDefaultOptions, true);

          if (!_options.history) {return;}

          _windowLoc = window.location;
          _urlChangedOnce = false;
          _closedFromURL = false;
          _historyChanged = false;
          _initialHash = _getHash();
          _supportsPushState = "pushState" in history;

          if (_initialHash.indexOf("gid=") > -1) {
            _initialHash = _initialHash.split("&gid=")[0];
            _initialHash = _initialHash.split("?gid=")[0];
          }

          _listen("afterChange", self.updateURL);
          _listen("unbindEvents", function () {
            framework.unbind(window, "hashchange", self.onHashChange);
          });

          var returnToOriginal = function () {
            _hashReseted = true;
            if (!_closedFromURL) {
              if (_urlChangedOnce) {history.back();} else {
                if (_initialHash) {
                  _windowLoc.hash = _initialHash;
                } else {
                  if (_supportsPushState) {
                    // remove hash from url without refreshing it or scrolling to top
                    history.pushState(
                      "",
                      document.title,
                      _windowLoc.pathname + _windowLoc.search
                    );
                  } else {
                    _windowLoc.hash = "";
                  }
                }
              }
            }

            _cleanHistoryTimeouts();
          };

          _listen("unbindEvents", function () {
            if (_closedByScroll) {
              // if PhotoSwipe is closed by scroll, we go "back" before the closing animation starts
              // this is done to keep the scroll position
              returnToOriginal();
            }
          });
          _listen("destroy", function () {
            if (!_hashReseted) {returnToOriginal();}
          });
          _listen("firstUpdate", function () {
            _currentItemIndex = _parseItemIndexFromURL().pid;
          });

          var index = _initialHash.indexOf("pid=");
          if (index > -1) {
            _initialHash = _initialHash.substring(0, index);
            if (_initialHash.slice(-1) === "&") {
              _initialHash = _initialHash.slice(0, -1);
            }
          }

          setTimeout(function () {
            if (_isOpen) {
              // hasn't destroyed yet
              framework.bind(window, "hashchange", self.onHashChange);
            }
          }, 40);
        },
        onHashChange: function () {
          if (_getHash() === _initialHash) {
            _closedFromURL = true;
            self.close();
            return;
          }
          if (!_hashChangedByScript) {
            _hashChangedByHistory = true;
            self.goTo(_parseItemIndexFromURL().pid);
            _hashChangedByHistory = false;
          }
        },
        updateURL: function () {
          // Delay the update of URL, to avoid lag during transition,
          // and to not to trigger actions like "refresh page sound" or "blinking favicon" to often

          _cleanHistoryTimeouts();

          if (_hashChangedByHistory) {return;}

          if (!_historyChanged) {
            _updateHash(); // first time
          } else {
            _historyUpdateTimeout = setTimeout(_updateHash, 800);
          }
        },
      },
    });

    /*>>history*/
    framework.extend(self, publicMethods);
  };
  return PhotoSwipe;
});