Elep

/*! tether 2.0.0-beta.5 */

(function (global, factory) {
  typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
  typeof define === 'function' && define.amd ? define(factory) :
  (global = global || self, global.Tether = factory());
}(this, (function () { 'use strict';

function _inheritsLoose(subClass, superClass) {
    subClass.prototype = Object.create(superClass.prototype);
    subClass.prototype.constructor = subClass;
    subClass.__proto__ = superClass;
  }

function _assertThisInitialized(self) {
    if (self === void 0) {
      throw new ReferenceError("this hasn't been initialised - super() hasn't been called");
    }

return self;
  }

/**
   * Checks if `value` is classified as a `Function` object.
   * @param {*} value The param to check if it is a function
   */
  function isFunction(value) {
    return typeof value === 'function';
  }
  /**
   * Checks if `value` is classified as a `Number` object.
   * @param {*} value The param to check if it is a number
   */

function isNumber(value) {
    return typeof value === 'number';
  }
  /**
   * Checks if `value` is classified as an `Object`.
   * @param {*} value The param to check if it is an object
   */

function isObject(value) {
    return typeof value === 'object';
  }
  /**
   * Checks if `value` is classified as a `String` object.
   * @param {*} value The param to check if it is a string
   */

function isString(value) {
    return typeof value === 'string';
  }
  /**
   * Checks if `value` is undefined.
   * @param {*} value The param to check if it is undefined
   */

function isUndefined(value) {
    return value === undefined;
  }

function addClass(el, name) {
    name.split(' ').forEach(function (cls) {
      if (cls.trim()) {
        el.classList.add(cls);
      }
    });
  }
  /**
   * Get class string based on previously determined classes
   * @param  {String} [key=''] - default value for the classes object
   * @param  {Object} classes
   * @param  {String} classPrefix
   */

function getClass(key, classes, classPrefix) {
    if (key === void 0) {
      key = '';
    }

if (!isUndefined(classes) && !isUndefined(classes[key])) {
      if (classes[key] === false) {
        return '';
      }

return classes[key];
    } else if (classPrefix) {
      return classPrefix + "-" + key;
    } else {
      return key;
    }
  }
  function removeClass(el, name) {
    name.split(' ').forEach(function (cls) {
      if (cls.trim()) {
        el.classList.remove(cls);
      }
    });
  }
  function updateClasses(el, add, all) {
    // Of the set of 'all' classes, we need the 'add' classes, and only the
    // 'add' classes to be set.
    all.forEach(function (cls) {
      if (add.indexOf(cls) === -1 && el.classList.contains(cls)) {
        removeClass(el, cls);
      }
    });
    add.forEach(function (cls) {
      if (!el.classList.contains(cls)) {
        addClass(el, cls);
      }
    });
  }

var deferred = [];
  function defer(fn) {
    deferred.push(fn);
  }
  function flush() {
    var fn; // eslint-disable-next-line

while (fn = deferred.pop()) {
      fn();
    }
  }

var _scrollBarSize = null;
  function extend(out) {
    if (out === void 0) {
      out = {};
    }

var inner = document.createElement('div');
    inner.style.width = '100%';
    inner.style.height = '200px';
    var outer = document.createElement('div');
    extend(outer.style, {
      position: 'absolute',
      top: 0,
      left: 0,
      pointerEvents: 'none',
      visibility: 'hidden',
      width: '200px',
      height: '150px',
      overflow: 'hidden'
    });
    outer.appendChild(inner);
    document.body.appendChild(outer);
    var widthContained = inner.offsetWidth;
    outer.style.overflow = 'scroll';
    var widthScroll = inner.offsetWidth;

if (widthContained === widthScroll) {
      widthScroll = outer.clientWidth;
    }

var zeroPosCache = {};
  var zeroElement = null;
  function getBounds(body, el) {
    var doc;

if (el === document) {
      doc = document;
      el = document.documentElement;
    } else {
      doc = el.ownerDocument;
    }

var docEl = doc.documentElement;

var box = _getActualBoundingClientRect(el);

var origin = _getOrigin(body);

box.top -= origin.top;
    box.left -= origin.left;

if (isUndefined(box.width)) {
      box.width = document.body.scrollWidth - box.left - box.right;
    }

if (isUndefined(box.height)) {
      box.height = document.body.scrollHeight - box.top - box.bottom;
    }

box.top = box.top - docEl.clientTop;
    box.left = box.left - docEl.clientLeft;
    box.right = doc.body.clientWidth - box.width - box.left;
    box.bottom = doc.body.clientHeight - box.height - box.top;
    return box;
  }
  /**
   * Gets bounds for when target modifiier is 'scroll-handle'
   * @param target
   * @return {{left: number, width: number, height: number}}
   */

function getScrollHandleBounds(body, target) {
    var bounds; // We have to do the check for the scrollTop and if target === document.body here and set to variables
    // because we may reset target below.

var targetScrollTop = target.scrollTop;
    var targetIsBody = target === document.body;

if (targetIsBody) {
      target = document.documentElement;
      bounds = {
        left: pageXOffset,
        top: pageYOffset,
        height: innerHeight,
        width: innerWidth
      };
    } else {
      bounds = getBounds(body, target);
    }

var style = getComputedStyle(target);
    var hasBottomScroll = target.scrollWidth > target.clientWidth || [style.overflow, style.overflowX].indexOf('scroll') >= 0 || !targetIsBody;
    var scrollBottom = 0;

if (hasBottomScroll) {
      scrollBottom = 15;
    }

var height = bounds.height - parseFloat(style.borderTopWidth) - parseFloat(style.borderBottomWidth) - scrollBottom;
    var out = {
      width: 15,
      height: height * 0.975 * (height / target.scrollHeight),
      left: bounds.left + bounds.width - parseFloat(style.borderLeftWidth) - 15
    };
    var fitAdj = 0;

if (height < 408 && targetIsBody) {
      fitAdj = -0.00011 * Math.pow(height, 2) - 0.00727 * height + 22.58;
    }

if (!targetIsBody) {
      out.height = Math.max(out.height, 24);
    }

var scrollPercentage = targetScrollTop / (target.scrollHeight - height);
    out.top = scrollPercentage * (height - out.height - fitAdj) + bounds.top + parseFloat(style.borderTopWidth);

if (targetIsBody) {
      out.height = Math.max(out.height, 24);
    }

return out;
  }
  /**
   * Gets bounds for when target modifiier is 'visible
   * @param target
   * @return {{top: *, left: *, width: *, height: *}}
   */

if (out.top < pageYOffset) {
        out.top = pageYOffset;
      }

if (out.left < pageXOffset) {
        out.left = pageXOffset;
      }

return out;
    }
  }
  function removeUtilElements(body) {
    if (zeroElement) {
      body.removeChild(zeroElement);
    }

zeroElement = null;
  }
  /**
   * Same as native getBoundingClientRect, except it takes into account parent <frame> offsets
   * if the element lies within a nested document (<frame> or <iframe>-like).
   * @param node
   */

function _getActualBoundingClientRect(node) {
    var boundingRect = node.getBoundingClientRect(); // The original object returned by getBoundingClientRect is immutable, so we clone it
    // We can't use extend because the properties are not considered part of the object by hasOwnProperty in IE9

var rect = {};

for (var k in boundingRect) {
      rect[k] = boundingRect[k];
    }

try {
      if (node.ownerDocument !== document) {
        var frameElement = node.ownerDocument.defaultView.frameElement;

if (frameElement) {
          var frameRect = _getActualBoundingClientRect(frameElement);

rect.top += frameRect.top;
          rect.bottom += frameRect.top;
          rect.left += frameRect.left;
          rect.right += frameRect.left;
        }
      }
    } catch (err) {// Ignore "Access is denied" in IE11/Edge
    }

return rect;
  }

function _getOrigin(body) {
    // getBoundingClientRect is unfortunately too accurate.  It introduces a pixel or two of
    // jitter as the user scrolls that messes with our ability to detect if two positions
    // are equivilant or not.  We place an element at the top left of the page that will
    // get the same jitter, so we can cancel the two out.
    var node = zeroElement;

if (!node || !body.contains(node)) {
      node = document.createElement('div');
      node.setAttribute('data-tether-id', uniqueId());
      extend(node.style, {
        top: 0,
        left: 0,
        position: 'absolute'
      });
      body.appendChild(node);
      zeroElement = node;
    }

var id = node.getAttribute('data-tether-id');

if (isUndefined(zeroPosCache[id])) {
      zeroPosCache[id] = _getActualBoundingClientRect(node); // Clear the cache when this position call is done

defer(function () {
        delete zeroPosCache[id];
      });
    }

return zeroPosCache[id];
  }

var Abutment = {
    position: function position(_ref) {
      var _this = this;

var top = _ref.top,
          left = _ref.left;

var _this$cache = this.cache('element-bounds', function () {
        return getBounds(_this.element);
      }),
          height = _this$cache.height,
          width = _this$cache.width;

var targetPos = this.getTargetBounds();
      var bottom = top + height;
      var right = left + width;
      var abutted = [];

if (top <= targetPos.bottom && bottom >= targetPos.top) {
        ['left', 'right'].forEach(function (side) {
          var targetPosSide = targetPos[side];

if (targetPosSide === left || targetPosSide === right) {
            abutted.push(side);
          }
        });
      }

if (left <= targetPos.right && right >= targetPos.left) {
        ['top', 'bottom'].forEach(function (side) {
          var targetPosSide = targetPos[side];

if (targetPosSide === top || targetPosSide === bottom) {
            abutted.push(side);
          }
        });
      }

var sides = ['left', 'top', 'right', 'bottom'];
      var _this$options = this.options,
          classes = _this$options.classes,
          classPrefix = _this$options.classPrefix;
      this.all.push(getClass('abutted', classes, classPrefix));
      sides.forEach(function (side) {
        _this.all.push(getClass('abutted', classes, classPrefix) + "-" + side);
      });

if (abutted.length) {
        this.add.push(getClass('abutted', classes, classPrefix));
      }

abutted.forEach(function (side) {
        _this.add.push(getClass('abutted', classes, classPrefix) + "-" + side);
      });
      defer(function () {
        if (!(_this.options.addTargetClasses === false)) {
          updateClasses(_this.target, _this.add, _this.all);
        }

updateClasses(_this.element, _this.add, _this.all);
      });
      return true;
    }
  };

var BOUNDS_FORMAT = ['left', 'top', 'right', 'bottom'];
  /**
   * Returns an array of bounds of the format [left, top, right, bottom]
   * @param tether
   * @param to
   * @return {*[]|HTMLElement|ActiveX.IXMLDOMElement}
   */

function getBoundingRect(body, tether, to) {
    // arg to is required
    if (!to) {
      return null;
    }

if (to === 'scrollParent') {
      to = tether.scrollParents[0];
    } else if (to === 'window') {
      to = [pageXOffset, pageYOffset, innerWidth + pageXOffset, innerHeight + pageYOffset];
    }

if (to === document) {
      to = to.documentElement;
    }

if (!isUndefined(to.nodeType)) {
      var node = to;
      var size = getBounds(body, to);
      var pos = size;
      var style = getComputedStyle(to);
      to = [pos.left, pos.top, size.width + pos.left, size.height + pos.top]; // Account any parent Frames scroll offset

if (node.ownerDocument !== document) {
        var win = node.ownerDocument.defaultView;
        to[0] += win.pageXOffset;
        to[1] += win.pageYOffset;
        to[2] += win.pageXOffset;
        to[3] += win.pageYOffset;
      }

BOUNDS_FORMAT.forEach(function (side, i) {
        side = side[0].toUpperCase() + side.substr(1);

if (side === 'Top' || side === 'Left') {
          to[i] += parseFloat(style["border" + side + "Width"]);
        } else {
          to[i] -= parseFloat(style["border" + side + "Width"]);
        }
      });
    }

return to;
  }
  /**
   * Add out of bounds classes to the list of classes we add to tether
   * @param {string[]} oob An array of directions that are out of bounds
   * @param {string[]} addClasses The array of classes to add to Tether
   * @param {string[]} classes The array of class types for Tether
   * @param {string} classPrefix The prefix to add to the front of the class
   * @param {string} outOfBoundsClass The class to apply when out of bounds
   * @private
   */

function _addOutOfBoundsClass(oob, addClasses, classes, classPrefix, outOfBoundsClass) {
    if (oob.length) {
      var oobClass;

if (!isUndefined(outOfBoundsClass)) {
        oobClass = outOfBoundsClass;
      } else {
        oobClass = getClass('out-of-bounds', classes, classPrefix);
      }

addClasses.push(oobClass);
      oob.forEach(function (side) {
        addClasses.push(oobClass + "-" + side);
      });
    }
  }
  /**
   * Calculates if out of bounds or pinned in the X direction.
   *
   * @param {number} left
   * @param {number[]} bounds Array of bounds of the format [left, top, right, bottom]
   * @param {number} width
   * @param pin
   * @param pinned
   * @param {string[]} oob
   * @return {number}
   * @private
   */

if (left + width > bounds[2]) {
      if (pin.indexOf('right') >= 0) {
        left = bounds[2] - width;
        pinned.push('right');
      } else {
        oob.push('right');
      }
    }

return left;
  }
  /**
   * Calculates if out of bounds or pinned in the Y direction.
   *
   * @param {number} top
   * @param {number[]} bounds Array of bounds of the format [left, top, right, bottom]
   * @param {number} height
   * @param pin
   * @param {string[]} pinned
   * @param {string[]} oob
   * @return {number}
   * @private
   */

if (top + height > bounds[3]) {
      if (pin.indexOf('bottom') >= 0) {
        top = bounds[3] - height;
        pinned.push('bottom');
      } else {
        oob.push('bottom');
      }
    }

return top;
  }
  /**
   * Flip X "together"
   * @param {object} tAttachment The target attachment
   * @param {object} eAttachment The element attachment
   * @param {number[]} bounds Array of bounds of the format [left, top, right, bottom]
   * @param {number} width
   * @param targetWidth
   * @param {number} left
   * @private
   */

return left;
  }
  /**
   * Flip Y "together"
   * @param {object} tAttachment The target attachment
   * @param {object} eAttachment The element attachment
   * @param {number[]} bounds Array of bounds of the format [left, top, right, bottom]
   * @param {number} height
   * @param targetHeight
   * @param {number} top
   * @private
   */

if (tAttachment.top === 'bottom') {
      if (eAttachment.top === 'top' && top + height > bounds[3]) {
        top -= targetHeight;
        tAttachment.top = 'top';
        top -= height;
        eAttachment.top = 'bottom';
      } else if (eAttachment.top === 'bottom' && top < bounds[1] && top + (height * 2 - targetHeight) <= bounds[3]) {
        top += height - targetHeight;
        tAttachment.top = 'top';
        eAttachment.top = 'top';
      }
    }

if (tAttachment.top === 'middle') {
      if (top + height > bounds[3] && eAttachment.top === 'top') {
        top -= height;
        eAttachment.top = 'bottom';
      } else if (top < bounds[1] && eAttachment.top === 'bottom') {
        top += height;
        eAttachment.top = 'top';
      }
    }

return top;
  }
  /**
   * Get all the initial classes
   * @param classes
   * @param {string} classPrefix
   * @param constraints
   * @return {[*, *]}
   * @private
   */

function _getAllClasses(classes, classPrefix, constraints) {
    var allClasses = [getClass('pinned', classes, classPrefix), getClass('out-of-bounds', classes, classPrefix)];
    constraints.forEach(function (constraint) {
      var outOfBoundsClass = constraint.outOfBoundsClass,
          pinnedClass = constraint.pinnedClass;

if (outOfBoundsClass) {
        allClasses.push(outOfBoundsClass);
      }

if (pinnedClass) {
        allClasses.push(pinnedClass);
      }
    });
    allClasses.forEach(function (cls) {
      ['left', 'top', 'right', 'bottom'].forEach(function (side) {
        allClasses.push(cls + "-" + side);
      });
    });
    return allClasses;
  }

var Constraint = {
    position: function position(_ref) {
      var _this = this;

var top = _ref.top,
          left = _ref.left,
          targetAttachment = _ref.targetAttachment;

if (!this.options.constraints) {
        return true;
      }

var _this$cache = this.cache('element-bounds', function () {
        return getBounds(_this.bodyElement, _this.element);
      }),
          height = _this$cache.height,
          width = _this$cache.width;

if (width === 0 && height === 0 && !isUndefined(this.lastSize)) {
        // Handle the item getting hidden as a result of our positioning without glitching
        // the classes in and out
        var _this$lastSize = this.lastSize;
        width = _this$lastSize.width;
        height = _this$lastSize.height;
      }

var targetSize = this.cache('target-bounds', function () {
        return _this.getTargetBounds();
      });
      var targetHeight = targetSize.height,
          targetWidth = targetSize.width;
      var _this$options = this.options,
          classes = _this$options.classes,
          classPrefix = _this$options.classPrefix;

var allClasses = _getAllClasses(classes, classPrefix, this.options.constraints);

var addClasses = [];
      var tAttachment = extend({}, targetAttachment);
      var eAttachment = extend({}, this.attachment);
      this.options.constraints.forEach(function (constraint) {
        var to = constraint.to,
            attachment = constraint.attachment,
            pin = constraint.pin;

if (isUndefined(attachment)) {
          attachment = '';
        }

var changeAttachX, changeAttachY;

if (attachment.indexOf(' ') >= 0) {
          var _attachment$split = attachment.split(' ');

changeAttachY = _attachment$split[0];
          changeAttachX = _attachment$split[1];
        } else {
          changeAttachX = changeAttachY = attachment;
        }

var bounds = getBoundingRect(_this.bodyElement, _this, to);

if (changeAttachY === 'target' || changeAttachY === 'both') {
          if (top < bounds[1] && tAttachment.top === 'top') {
            top += targetHeight;
            tAttachment.top = 'bottom';
          }

if (top + height > bounds[3] && tAttachment.top === 'bottom') {
            top -= targetHeight;
            tAttachment.top = 'top';
          }
        }

if (changeAttachY === 'together') {
          top = _flipYTogether(tAttachment, eAttachment, bounds, height, targetHeight, top);
        }

if (changeAttachX === 'target' || changeAttachX === 'both') {
          if (left < bounds[0] && tAttachment.left === 'left') {
            left += targetWidth;
            tAttachment.left = 'right';
          }

if (left + width > bounds[2] && tAttachment.left === 'right') {
            left -= targetWidth;
            tAttachment.left = 'left';
          }
        }

if (changeAttachX === 'together') {
          left = _flipXTogether(tAttachment, eAttachment, bounds, width, targetWidth, left);
        }

if (changeAttachY === 'element' || changeAttachY === 'both') {
          if (top < bounds[1] && eAttachment.top === 'bottom') {
            top += height;
            eAttachment.top = 'top';
          }

if (top + height > bounds[3] && eAttachment.top === 'top') {
            top -= height;
            eAttachment.top = 'bottom';
          }
        }

if (changeAttachX === 'element' || changeAttachX === 'both') {
          if (left < bounds[0]) {
            if (eAttachment.left === 'right') {
              left += width;
              eAttachment.left = 'left';
            } else if (eAttachment.left === 'center') {
              left += width / 2;
              eAttachment.left = 'left';
            }
          }

if (left + width > bounds[2]) {
            if (eAttachment.left === 'left') {
              left -= width;
              eAttachment.left = 'right';
            } else if (eAttachment.left === 'center') {
              left -= width / 2;
              eAttachment.left = 'right';
            }
          }
        }

if (isString(pin)) {
          pin = pin.split(',').map(function (p) {
            return p.trim();
          });
        } else if (pin === true) {
          pin = ['top', 'left', 'right', 'bottom'];
        }

pin = pin || [];
        var pinned = [];
        var oob = [];
        left = _calculateOOBAndPinnedLeft(left, bounds, width, pin, pinned, oob);
        top = _calculateOOBAndPinnedTop(top, bounds, height, pin, pinned, oob);

if (pinned.length) {
          var pinnedClass;

if (!isUndefined(_this.options.pinnedClass)) {
            pinnedClass = _this.options.pinnedClass;
          } else {
            pinnedClass = getClass('pinned', classes, classPrefix);
          }

addClasses.push(pinnedClass);
          pinned.forEach(function (side) {
            addClasses.push(pinnedClass + "-" + side);
          });
        }

_addOutOfBoundsClass(oob, addClasses, classes, classPrefix, _this.options.outOfBoundsClass);

if (pinned.indexOf('left') >= 0 || pinned.indexOf('right') >= 0) {
          eAttachment.left = tAttachment.left = false;
        }

if (pinned.indexOf('top') >= 0 || pinned.indexOf('bottom') >= 0) {
          eAttachment.top = tAttachment.top = false;
        }

if (tAttachment.top !== targetAttachment.top || tAttachment.left !== targetAttachment.left || eAttachment.top !== _this.attachment.top || eAttachment.left !== _this.attachment.left) {
          _this.updateAttachClasses(eAttachment, tAttachment);

_this.trigger('update', {
            attachment: eAttachment,
            targetAttachment: tAttachment
          });
        }
      });
      defer(function () {
        if (!(_this.options.addTargetClasses === false)) {
          updateClasses(_this.target, addClasses, allClasses);
        }

updateClasses(_this.element, addClasses, allClasses);
      });
      return {
        top: top,
        left: left
      };
    }
  };

var Shift = {
    position: function position(_ref) {
      var top = _ref.top,
          left = _ref.left;

if (!this.options.shift) {
        return;
      }

var shift = this.options.shift;

if (isFunction(shift)) {
        shift = shift.call(this, {
          top: top,
          left: left
        });
      }

var shiftTop, shiftLeft;

if (isString(shift)) {
        shift = shift.split(' ');
        shift[1] = shift[1] || shift[0];
        var _shift = shift;
        shiftTop = _shift[0];
        shiftLeft = _shift[1];
        shiftTop = parseFloat(shiftTop, 10);
        shiftLeft = parseFloat(shiftLeft, 10);
      } else {
        var _ref2 = [shift.top, shift.left];
        shiftTop = _ref2[0];
        shiftLeft = _ref2[1];
      }

top += shiftTop;
      left += shiftLeft;
      return {
        top: top,
        left: left
      };
    }
  };

var Evented =
  /*#__PURE__*/
  function () {
    function Evented() {}

var _proto = Evented.prototype;

_proto.on = function on(event, handler, ctx, once) {
      if (once === void 0) {
        once = false;
      }

if (isUndefined(this.bindings)) {
        this.bindings = {};
      }

if (isUndefined(this.bindings[event])) {
        this.bindings[event] = [];
      }

this.bindings[event].push({
        handler: handler,
        ctx: ctx,
        once: once
      });
      return this;
    };

_proto.once = function once(event, handler, ctx) {
      return this.on(event, handler, ctx, true);
    };

_proto.off = function off(event, handler) {
      var _this = this;

if (isUndefined(this.bindings) || isUndefined(this.bindings[event])) {
        return this;
      }

if (isUndefined(handler)) {
        delete this.bindings[event];
      } else {
        this.bindings[event].forEach(function (binding, index) {
          if (binding.handler === handler) {
            _this.bindings[event].splice(index, 1);
          }
        });
      }

return this;
    };

_proto.trigger = function trigger(event) {
      var _this2 = this;

for (var _len = arguments.length, args = new Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
        args[_key - 1] = arguments[_key];
      }

if (!isUndefined(this.bindings) && this.bindings[event]) {
        this.bindings[event].forEach(function (binding, index) {
          var ctx = binding.ctx,
              handler = binding.handler,
              once = binding.once;
          var context = ctx || _this2;
          handler.apply(context, args);

if (once) {
            _this2.bindings[event].splice(index, 1);
          }
        });
      }

return this;
    };

return Evented;
  }();

for (var _len = arguments.length, offsets = new Array(_len), _key = 0; _key < _len; _key++) {
      offsets[_key] = arguments[_key];
    }

offsets.forEach(function (_ref) {
      var top = _ref.top,
          left = _ref.left;

if (isString(top)) {
        top = parseFloat(top);
      }

if (isString(left)) {
        left = parseFloat(left);
      }

out.top += top;
      out.left += left;
    });
    return out;
  }
  function attachmentToOffset(attachment) {
    var left = attachment.left,
        top = attachment.top;

if (!isUndefined(OFFSET_MAP[attachment.left])) {
      left = OFFSET_MAP[attachment.left];
    }

if (!isUndefined(OFFSET_MAP[attachment.top])) {
      top = OFFSET_MAP[attachment.top];
    }

return {
      left: left,
      top: top
    };
  }
  function autoToFixedAttachment(attachment, relativeToAttachment) {
    var left = attachment.left,
        top = attachment.top;

if (left === 'auto') {
      left = MIRROR_LR[relativeToAttachment.left];
    }

if (top === 'auto') {
      top = MIRROR_TB[relativeToAttachment.top];
    }

return {
      left: left,
      top: top
    };
  }
  function offsetToPx(offset, size) {
    if (isString(offset.left) && offset.left.indexOf('%') !== -1) {
      offset.left = parseFloat(offset.left) / 100 * size.width;
    }

if (isString(offset.top) && offset.top.indexOf('%') !== -1) {
      offset.top = parseFloat(offset.top) / 100 * size.height;
    }

return offset;
  }
  function parseTopLeft(value) {
    var _value$split = value.split(' '),
        top = _value$split[0],
        left = _value$split[1];

return {
      top: top,
      left: left
    };
  }

function getScrollParents(el) {
    // In firefox if the el is inside an iframe with display: none; window.getComputedStyle() will return null;
    // https://bugzilla.mozilla.org/show_bug.cgi?id=548397
    var computedStyle = getComputedStyle(el) || {};
    var position = computedStyle.position;
    var parents = [];

if (position === 'fixed') {
      return [el];
    }

var parent = el;

while ((parent = parent.parentNode) && parent && parent.nodeType === 1) {
      var style = void 0;

try {
        style = getComputedStyle(parent);
      } catch (err) {// Intentionally blank
      }

if (isUndefined(style) || style === null) {
        parents.push(parent);
        return parents;
      }

var _style = style,
          overflow = _style.overflow,
          overflowX = _style.overflowX,
          overflowY = _style.overflowY;

if (/(auto|scroll|overlay)/.test(overflow + overflowY + overflowX)) {
        if (position !== 'absolute' || ['relative', 'absolute', 'fixed'].indexOf(style.position) >= 0) {
          parents.push(parent);
        }
      }
    }

parents.push(el.ownerDocument.body); // If the node is within a frame, account for the parent window scroll

if (el.ownerDocument !== document) {
      parents.push(el.ownerDocument.defaultView);
    }

return parents;
  }
  function getOffsetParent(el) {
    return el.offsetParent || document.documentElement;
  }

var TetherBase = {
    modules: [Constraint, Abutment, Shift]
  };

function isFullscreenElement(e) {
    var d = e.ownerDocument;
    var fe = d.fullscreenElement || d.webkitFullscreenElement || d.mozFullScreenElement || d.msFullscreenElement;
    return fe === e;
  }

function within(a, b, diff) {
    if (diff === void 0) {
      diff = 1;
    }

return a + diff >= b && b >= a - diff;
  }

var transformKey = function () {
    if (isUndefined(document)) {
      return '';
    }

var el = document.createElement('div');
    var transforms = ['transform', 'WebkitTransform', 'OTransform', 'MozTransform', 'msTransform'];

for (var i = 0; i < transforms.length; ++i) {
      var key = transforms[i];

if (el.style[key] !== undefined) {
        return key;
      }
    }
  }();

var tethers = [];

var position = function position() {
    tethers.forEach(function (tether) {
      tether.position(false);
    });
    flush();
  };

function now() {
    return performance.now();
  }

(function () {
    var lastCall = null;
    var lastDuration = null;
    var pendingTimeout = null;

var tick = function tick() {
      if (!isUndefined(lastDuration) && lastDuration > 16) {
        // We voluntarily throttle ourselves if we can't manage 60fps
        lastDuration = Math.min(lastDuration - 16, 250); // Just in case this is the last event, remember to position just once more

pendingTimeout = setTimeout(tick, 250);
        return;
      }

if (!isUndefined(lastCall) && now() - lastCall < 10) {
        // Some browsers call events a little too frequently, refuse to run more than is reasonable
        return;
      }

if (pendingTimeout != null) {
        clearTimeout(pendingTimeout);
        pendingTimeout = null;
      }

lastCall = now();
      position();
      lastDuration = now() - lastCall;
    };

if (!isUndefined(window) && !isUndefined(window.addEventListener)) {
      ['resize', 'scroll', 'touchmove'].forEach(function (event) {
        window.addEventListener(event, tick);
      });
    }
  })();

var TetherClass =
  /*#__PURE__*/
  function (_Evented) {
    _inheritsLoose(TetherClass, _Evented);

function TetherClass(options) {
      var _this;

_this = _Evented.call(this) || this;
      _this.position = _this.position.bind(_assertThisInitialized(_this));
      tethers.push(_assertThisInitialized(_this));
      _this.history = [];

_this.setOptions(options, false);

TetherBase.modules.forEach(function (module) {
        if (!isUndefined(module.initialize)) {
          module.initialize.call(_assertThisInitialized(_this));
        }
      });

_this.position();

return _this;
    }

var _proto = TetherClass.prototype;

_proto.setOptions = function setOptions(options, pos) {
      var _this2 = this;

if (pos === void 0) {
        pos = true;
      }

var defaults = {
        offset: '0 0',
        targetOffset: '0 0',
        targetAttachment: 'auto auto',
        classPrefix: 'tether',
        bodyElement: document.body
      };
      this.options = extend(defaults, options);
      var _this$options = this.options,
          element = _this$options.element,
          target = _this$options.target,
          targetModifier = _this$options.targetModifier,
          bodyElement = _this$options.bodyElement;
      this.element = element;
      this.target = target;
      this.targetModifier = targetModifier;

if (typeof bodyElement === 'string') {
        bodyElement = document.querySelector(bodyElement);
      }

this.bodyElement = bodyElement;

if (this.target === 'viewport') {
        this.target = document.body;
        this.targetModifier = 'visible';
      } else if (this.target === 'scroll-handle') {
        this.target = document.body;
        this.targetModifier = 'scroll-handle';
      }

['element', 'target'].forEach(function (key) {
        if (isUndefined(_this2[key])) {
          throw new Error('Tether Error: Both element and target must be defined');
        }

if (!isUndefined(_this2[key].jquery)) {
          _this2[key] = _this2[key][0];
        } else if (isString(_this2[key])) {
          _this2[key] = document.querySelector(_this2[key]);
        }
      });

this._addClasses();

if (!this.options.attachment) {
        throw new Error('Tether Error: You must provide an attachment');
      }

this.targetAttachment = parseTopLeft(this.options.targetAttachment);
      this.attachment = parseTopLeft(this.options.attachment);
      this.offset = parseTopLeft(this.options.offset);
      this.targetOffset = parseTopLeft(this.options.targetOffset);

if (!isUndefined(this.scrollParents)) {
        this.disable();
      }

if (this.targetModifier === 'scroll-handle') {
        this.scrollParents = [this.target];
      } else {
        this.scrollParents = getScrollParents(this.target);
      }

if (!(this.options.enabled === false)) {
        this.enable(pos);
      }
    };

_proto.getTargetBounds = function getTargetBounds() {
      if (!isUndefined(this.targetModifier)) {
        if (this.targetModifier === 'visible') {
          return getVisibleBounds(this.bodyElement, this.target);
        } else if (this.targetModifier === 'scroll-handle') {
          return getScrollHandleBounds(this.bodyElement, this.target);
        }
      } else {
        return getBounds(this.bodyElement, this.target);
      }
    };

_proto.clearCache = function clearCache() {
      this._cache = {};
    };

_proto.cache = function cache(k, getter) {
      // More than one module will often need the same DOM info, so
      // we keep a cache which is cleared on each position call
      if (isUndefined(this._cache)) {
        this._cache = {};
      }

if (isUndefined(this._cache[k])) {
        this._cache[k] = getter.call(this);
      }

return this._cache[k];
    };

_proto.enable = function enable(pos) {
      var _this3 = this;

if (pos === void 0) {
        pos = true;
      }

var _this$options2 = this.options,
          classes = _this$options2.classes,
          classPrefix = _this$options2.classPrefix;

if (!(this.options.addTargetClasses === false)) {
        addClass(this.target, getClass('enabled', classes, classPrefix));
      }

addClass(this.element, getClass('enabled', classes, classPrefix));
      this.enabled = true;
      this.scrollParents.forEach(function (parent) {
        if (parent !== _this3.target.ownerDocument) {
          parent.addEventListener('scroll', _this3.position);
        }
      });

if (pos) {
        this.position();
      }
    };

_proto.disable = function disable() {
      var _this4 = this;

var _this$options3 = this.options,
          classes = _this$options3.classes,
          classPrefix = _this$options3.classPrefix;
      removeClass(this.target, getClass('enabled', classes, classPrefix));
      removeClass(this.element, getClass('enabled', classes, classPrefix));
      this.enabled = false;

if (!isUndefined(this.scrollParents)) {
        this.scrollParents.forEach(function (parent) {
          parent.removeEventListener('scroll', _this4.position);
        });
      }
    };

_proto.destroy = function destroy() {
      var _this5 = this;

this.disable();

this._removeClasses();

tethers.forEach(function (tether, i) {
        if (tether === _this5) {
          tethers.splice(i, 1);
        }
      }); // Remove any elements we were using for convenience from the DOM

if (tethers.length === 0) {
        removeUtilElements(this.bodyElement);
      }
    };

_proto.updateAttachClasses = function updateAttachClasses(elementAttach, targetAttach) {
      var _this6 = this;

elementAttach = elementAttach || this.attachment;
      targetAttach = targetAttach || this.targetAttachment;
      var sides = ['left', 'top', 'bottom', 'right', 'middle', 'center'];
      var _this$options4 = this.options,
          classes = _this$options4.classes,
          classPrefix = _this$options4.classPrefix;

if (!isUndefined(this._addAttachClasses) && this._addAttachClasses.length) {
        // updateAttachClasses can be called more than once in a position call, so
        // we need to clean up after ourselves such that when the last defer gets
        // ran it doesn't add any extra classes from previous calls.
        this._addAttachClasses.splice(0, this._addAttachClasses.length);
      }

if (isUndefined(this._addAttachClasses)) {
        this._addAttachClasses = [];
      }

this.add = this._addAttachClasses;

if (elementAttach.top) {
        this.add.push(getClass('element-attached', classes, classPrefix) + "-" + elementAttach.top);
      }

if (elementAttach.left) {
        this.add.push(getClass('element-attached', classes, classPrefix) + "-" + elementAttach.left);
      }

if (targetAttach.top) {
        this.add.push(getClass('target-attached', classes, classPrefix) + "-" + targetAttach.top);
      }

if (targetAttach.left) {
        this.add.push(getClass('target-attached', classes, classPrefix) + "-" + targetAttach.left);
      }

this.all = [];
      sides.forEach(function (side) {
        _this6.all.push(getClass('element-attached', classes, classPrefix) + "-" + side);

_this6.all.push(getClass('target-attached', classes, classPrefix) + "-" + side);
      });
      defer(function () {
        if (isUndefined(_this6._addAttachClasses)) {
          return;
        }

updateClasses(_this6.element, _this6._addAttachClasses, _this6.all);

if (!(_this6.options.addTargetClasses === false)) {
          updateClasses(_this6.target, _this6._addAttachClasses, _this6.all);
        }

delete _this6._addAttachClasses;
      });
    };

_proto.position = function position(flushChanges) {
      var _this7 = this;

if (flushChanges === void 0) {
        flushChanges = true;
      }

// flushChanges commits the changes immediately, leave true unless you are positioning multiple
      // tethers (in which case call Tether.Utils.flush yourself when you're done)
      if (!this.enabled) {
        return;
      }

this.clearCache(); // Turn 'auto' attachments into the appropriate corner or edge

var targetAttachment = autoToFixedAttachment(this.targetAttachment, this.attachment);
      this.updateAttachClasses(this.attachment, targetAttachment);
      var elementPos = this.cache('element-bounds', function () {
        return getBounds(_this7.bodyElement, _this7.element);
      });
      var width = elementPos.width,
          height = elementPos.height;

if (width === 0 && height === 0 && !isUndefined(this.lastSize)) {
        // We cache the height and width to make it possible to position elements that are
        // getting hidden.
        var _this$lastSize = this.lastSize;
        width = _this$lastSize.width;
        height = _this$lastSize.height;
      } else {
        this.lastSize = {
          width: width,
          height: height
        };
      }

var targetPos = this.cache('target-bounds', function () {
        return _this7.getTargetBounds();
      });
      var targetSize = targetPos; // Get an actual px offset from the attachment

var offset = offsetToPx(attachmentToOffset(this.attachment), {
        width: width,
        height: height
      });
      var targetOffset = offsetToPx(attachmentToOffset(targetAttachment), targetSize);
      var manualOffset = offsetToPx(this.offset, {
        width: width,
        height: height
      });
      var manualTargetOffset = offsetToPx(this.targetOffset, targetSize); // Add the manually provided offset

offset = addOffset(offset, manualOffset);
      targetOffset = addOffset(targetOffset, manualTargetOffset); // It's now our goal to make (element position + offset) == (target position + target offset)

var left = targetPos.left + targetOffset.left - offset.left;
      var top = targetPos.top + targetOffset.top - offset.top;

for (var i = 0; i < TetherBase.modules.length; ++i) {
        var module = TetherBase.modules[i];
        var ret = module.position.call(this, {
          left: left,
          top: top,
          targetAttachment: targetAttachment,
          targetPos: targetPos,
          elementPos: elementPos,
          offset: offset,
          targetOffset: targetOffset,
          manualOffset: manualOffset,
          manualTargetOffset: manualTargetOffset,
          scrollbarSize: scrollbarSize,
          attachment: this.attachment
        });

if (ret === false) {
          return false;
        } else if (isUndefined(ret) || !isObject(ret)) {
          continue;
        } else {
          top = ret.top;
          left = ret.left;
        }
      } // We describe the position three different ways to give the optimizer
      // a chance to decide the best possible way to position the element
      // with the fewest repaints.

if (win.innerHeight > doc.documentElement.clientHeight) {
        scrollbarSize = this.cache('scrollbar-size', getScrollBarSize);
        next.viewport.bottom -= scrollbarSize.height;
      }

if (win.innerWidth > doc.documentElement.clientWidth) {
        scrollbarSize = this.cache('scrollbar-size', getScrollBarSize);
        next.viewport.right -= scrollbarSize.width;
      }

if (['', 'static'].indexOf(doc.body.style.position) === -1 || ['', 'static'].indexOf(doc.body.parentElement.style.position) === -1) {
        // Absolute positioning in the body will be relative to the page, not the 'initial containing block'
        next.page.bottom = doc.body.scrollHeight - top - height;
        next.page.right = doc.body.scrollWidth - left - width;
      }

if (!isUndefined(this.options.optimizations) && this.options.optimizations.moveElement !== false && isUndefined(this.targetModifier)) {
        var offsetParent = this.cache('target-offsetparent', function () {
          return getOffsetParent(_this7.target);
        });
        var offsetPosition = this.cache('target-offsetparent-bounds', function () {
          return getBounds(_this7.bodyElement, offsetParent);
        });
        var offsetParentStyle = getComputedStyle(offsetParent);
        var offsetParentSize = offsetPosition;
        var offsetBorder = {};
        ['Top', 'Left', 'Bottom', 'Right'].forEach(function (side) {
          offsetBorder[side.toLowerCase()] = parseFloat(offsetParentStyle["border" + side + "Width"]);
        });
        offsetPosition.right = doc.body.scrollWidth - offsetPosition.left - offsetParentSize.width + offsetBorder.right;
        offsetPosition.bottom = doc.body.scrollHeight - offsetPosition.top - offsetParentSize.height + offsetBorder.bottom;

if (next.page.top >= offsetPosition.top + offsetBorder.top && next.page.bottom >= offsetPosition.bottom) {
          if (next.page.left >= offsetPosition.left + offsetBorder.left && next.page.right >= offsetPosition.right) {
            // We're within the visible part of the target's scroll parent
            var scrollLeft = offsetParent.scrollLeft,
                scrollTop = offsetParent.scrollTop; // It's position relative to the target's offset parent (absolute positioning when
            // the element is moved to be a child of the target's offset parent).

next.offset = {
              top: next.page.top - offsetPosition.top + scrollTop - offsetBorder.top,
              left: next.page.left - offsetPosition.left + scrollLeft - offsetBorder.left
            };
          }
        }
      } // We could also travel up the DOM and try each containing context, rather than only
      // looking at the body, but we're gonna get diminishing returns.

this.move(next);
      this.history.unshift(next);

if (this.history.length > 3) {
        this.history.pop();
      }

if (flushChanges) {
        flush();
      }

return true;
    } // THE ISSUE
    ;

_proto.move = function move(pos) {
      var _this8 = this;

if (isUndefined(this.element.parentNode)) {
        return;
      }

var same = {};

for (var type in pos) {
        same[type] = {};

for (var key in pos[type]) {
          var found = false;

for (var i = 0; i < this.history.length; ++i) {
            var point = this.history[i];

if (!isUndefined(point[type]) && !within(point[type][key], pos[type][key])) {
              found = true;
              break;
            }
          }

if (!found) {
            same[type][key] = true;
          }
        }
      }

var css = {
        top: '',
        left: '',
        right: '',
        bottom: ''
      };

var transcribe = function transcribe(_same, _pos) {
        var hasOptimizations = !isUndefined(_this8.options.optimizations);
        var gpu = hasOptimizations ? _this8.options.optimizations.gpu : null;

if (gpu !== false) {
          var yPos, xPos;

if (_same.top) {
            css.top = 0;
            yPos = _pos.top;
          } else {
            css.bottom = 0;
            yPos = -_pos.bottom;
          }

if (_same.left) {
            css.left = 0;
            xPos = _pos.left;
          } else {
            css.right = 0;
            xPos = -_pos.right;
          }

if (isNumber(window.devicePixelRatio) && devicePixelRatio % 1 === 0) {
            xPos = Math.round(xPos * devicePixelRatio) / devicePixelRatio;
            yPos = Math.round(yPos * devicePixelRatio) / devicePixelRatio;
          }

css[transformKey] = "translateX(" + xPos + "px) translateY(" + yPos + "px)";

if (transformKey !== 'msTransform') {
            // The Z transform will keep this in the GPU (faster, and prevents artifacts),
            // but IE9 doesn't support 3d transforms and will choke.
            css[transformKey] += ' translateZ(0)';
          }
        } else {
          if (_same.top) {
            css.top = _pos.top + "px";
          } else {
            css.bottom = _pos.bottom + "px";
          }

if (_same.left) {
            css.left = _pos.left + "px";
          } else {
            css.right = _pos.right + "px";
          }
        }
      };

var hasOptimizations = !isUndefined(this.options.optimizations);
      var allowPositionFixed = true;

if (hasOptimizations && this.options.optimizations.allowPositionFixed === false) {
        allowPositionFixed = false;
      }

var moved = false;

if ((same.page.top || same.page.bottom) && (same.page.left || same.page.right)) {
        css.position = 'absolute';
        transcribe(same.page, pos.page);
      } else if (allowPositionFixed && (same.viewport.top || same.viewport.bottom) && (same.viewport.left || same.viewport.right)) {
        css.position = 'fixed';
        transcribe(same.viewport, pos.viewport);
      } else if (!isUndefined(same.offset) && same.offset.top && same.offset.left) {
        css.position = 'absolute';
        var offsetParent = this.cache('target-offsetparent', function () {
          return getOffsetParent(_this8.target);
        });

if (getOffsetParent(this.element) !== offsetParent) {
          defer(function () {
            _this8.element.parentNode.removeChild(_this8.element);

offsetParent.appendChild(_this8.element);
          });
        }

transcribe(same.offset, pos.offset);
        moved = true;
      } else {
        css.position = 'absolute';
        transcribe({
          top: true,
          left: true
        }, pos.page);
      }

if (!moved) {
        if (this.options.bodyElement) {
          if (this.element.parentNode !== this.options.bodyElement) {
            this.options.bodyElement.appendChild(this.element);
          }
        } else {
          var offsetParentIsBody = true;
          var currentNode = this.element.parentNode;

while (currentNode && currentNode.nodeType === 1 && currentNode.tagName !== 'BODY' && !isFullscreenElement(currentNode)) {
            if (getComputedStyle(currentNode).position !== 'static') {
              offsetParentIsBody = false;
              break;
            }

currentNode = currentNode.parentNode;
          }

if (!offsetParentIsBody) {
            this.element.parentNode.removeChild(this.element);
            this.element.ownerDocument.body.appendChild(this.element);
          }
        }
      } // Any css change will trigger a repaint, so let's avoid one if nothing changed

var writeCSS = {};
      var write = false;

for (var _key in css) {
        var val = css[_key];
        var elVal = this.element.style[_key];

if (elVal !== val) {
          write = true;
          writeCSS[_key] = val;
        }
      }

if (write) {
        defer(function () {
          extend(_this8.element.style, writeCSS);

_this8.trigger('repositioned');
        });
      }
    };

_proto._addClasses = function _addClasses() {
      var _this$options5 = this.options,
          classes = _this$options5.classes,
          classPrefix = _this$options5.classPrefix;
      addClass(this.element, getClass('element', classes, classPrefix));

if (!(this.options.addTargetClasses === false)) {
        addClass(this.target, getClass('target', classes, classPrefix));
      }
    };

_proto._removeClasses = function _removeClasses() {
      var _this9 = this;

var _this$options6 = this.options,
          classes = _this$options6.classes,
          classPrefix = _this$options6.classPrefix;
      removeClass(this.element, getClass('element', classes, classPrefix));

if (!(this.options.addTargetClasses === false)) {
        removeClass(this.target, getClass('target', classes, classPrefix));
      }

this.all.forEach(function (className) {
        _this9.element.classList.remove(className);

_this9.target.classList.remove(className);
      });
    };

return TetherClass;
  }(Evented);

TetherClass.modules = [];
  TetherBase.position = position;
  var Tether = extend(TetherClass, TetherBase);
  Tether.modules.push({
    initialize: function initialize() {
      var _this10 = this;

var _this$options7 = this.options,
          classes = _this$options7.classes,
          classPrefix = _this$options7.classPrefix;
      this.markers = {};
      ['target', 'element'].forEach(function (type) {
        var el = document.createElement('div');
        el.className = getClass(type + "-marker", classes, classPrefix);
        var dot = document.createElement('div');
        dot.className = getClass('marker-dot', classes, classPrefix);
        el.appendChild(dot);

_this10[type].appendChild(el);

_this10.markers[type] = {
          dot: dot,
          el: el
        };
      });
    },
    position: function position(_ref) {
      var manualOffset = _ref.manualOffset,
          manualTargetOffset = _ref.manualTargetOffset;
      var offsets = {
        element: manualOffset,
        target: manualTargetOffset
      };

for (var type in offsets) {
        var offset = offsets[type];

for (var side in offset) {
          var val = offset[side];

if (!isString(val) || val.indexOf('%') === -1 && val.indexOf('px') === -1) {
            val += 'px';
          }

if (this.markers[type].dot.style[side] !== val) {
            this.markers[type].dot.style[side] = val;
          }
        }
      }

return true;
    }
  });

return Tether;

})));
//# sourceMappingURL=tether.js.map