scrollspy.js

'use strict';

var _createClass = (function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ('value' in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; })();

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError('Cannot call a class as a function'); } }

/**
 * --------------------------------------------------------------------------
 * Bootstrap (v4.0.0): scrollspy.js
 * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
 * --------------------------------------------------------------------------
 */

var ScrollSpy = (function ($) {

  /**
   * ------------------------------------------------------------------------
   * Constants
   * ------------------------------------------------------------------------
   */

  var NAME = 'scrollspy';
  var VERSION = '4.0.0';
  var DATA_KEY = 'bs.scrollspy';
  var EVENT_KEY = '.' + DATA_KEY;
  var DATA_API_KEY = '.data-api';
  var JQUERY_NO_CONFLICT = $.fn[NAME];

  var Default = {
    offset: 10
  };

  var Event = {
    ACTIVATE: 'activate' + EVENT_KEY,
    SCROLL: 'scroll' + EVENT_KEY,
    LOAD_DATA_API: 'load' + EVENT_KEY + '' + DATA_API_KEY
  };

  var ClassName = {
    DROPDOWN_MENU: 'dropdown-menu',
    ACTIVE: 'active'
  };

  var Selector = {
    DATA_SPY: '[data-spy="scroll"]',
    ACTIVE: '.active',
    LI_DROPDOWN: 'li.dropdown',
    LI: 'li'
  };

  /**
   * ------------------------------------------------------------------------
   * Class Definition
   * ------------------------------------------------------------------------
   */

  var ScrollSpy = (function () {
    function ScrollSpy(element, config) {
      _classCallCheck(this, ScrollSpy);

      this._element = element;
      this._scrollElement = element.tagName === 'BODY' ? window : element;
      this._config = $.extend({}, Default, config);
      this._selector = '' + (this._config.target || '') + ' .nav li > a';
      this._offsets = [];
      this._targets = [];
      this._activeTarget = null;
      this._scrollHeight = 0;

      $(this._scrollElement).on(Event.SCROLL, $.proxy(this._process, this));

      this.refresh();
      this._process();
    }

    _createClass(ScrollSpy, [{
      key: 'refresh',

      // public

      value: function refresh() {
        var _this = this;

        var offsetMethod = 'offset';
        var offsetBase = 0;

        if (this._scrollElement !== this._scrollElement.window) {
          offsetMethod = 'position';
          offsetBase = this._getScrollTop();
        }

        this._offsets = [];
        this._targets = [];

        this._scrollHeight = this._getScrollHeight();

        var targets = $.makeArray($(this._selector));

        targets.map(function (element) {
          var target = undefined;
          var targetSelector = Util.getSelectorFromElement(element);

          if (targetSelector) {
            target = $(targetSelector)[0];
          }

          if (target && (target.offsetWidth || target.offsetHeight)) {
            // todo (fat): remove sketch reliance on jQuery position/offset
            return [$(target)[offsetMethod]().top + offsetBase, targetSelector];
          }
        }).filter(function (item) {
          return item;
        }).sort(function (a, b) {
          return a[0] - b[0];
        }).forEach(function (item) {
          _this._offsets.push(item[0]);
          _this._targets.push(item[1]);
        });
      }
    }, {
      key: 'dispose',
      value: function dispose() {
        $.removeData(this._element, DATA_KEY);
        $(this._scrollElement).off(EVENT_KEY);

        this._element = null;
        this._scrollElement = null;
        this._config = null;
        this._selector = null;
        this._offsets = null;
        this._targets = null;
        this._activeTarget = null;
        this._scrollHeight = null;
      }
    }, {
      key: '_getScrollTop',

      // private

      value: function _getScrollTop() {
        return this._scrollElement === window ? this._scrollElement.scrollY : this._scrollElement.scrollTop;
      }
    }, {
      key: '_getScrollHeight',
      value: function _getScrollHeight() {
        return this._scrollElement.scrollHeight || Math.max(document.body.scrollHeight, document.documentElement.scrollHeight);
      }
    }, {
      key: '_process',
      value: function _process() {
        var scrollTop = this._getScrollTop() + this._config.offset;
        var scrollHeight = this._getScrollHeight();
        var maxScroll = this._config.offset + scrollHeight - this._scrollElement.offsetHeight;

        if (this._scrollHeight !== scrollHeight) {
          this.refresh();
        }

        if (scrollTop >= maxScroll) {
          var target = this._targets[this._targets.length - 1];

          if (this._activeTarget !== target) {
            this._activate(target);
          }
        }

        if (this._activeTarget && scrollTop < this._offsets[0]) {
          this._activeTarget = null;
          this._clear();
          return;
        }

        for (var i = this._offsets.length; i--;) {
          var isActiveTarget = this._activeTarget !== this._targets[i] && scrollTop >= this._offsets[i] && (this._offsets[i + 1] === undefined || scrollTop < this._offsets[i + 1]);

          if (isActiveTarget) {
            this._activate(this._targets[i]);
          }
        }
      }
    }, {
      key: '_activate',
      value: function _activate(target) {
        this._activeTarget = target;

        this._clear();

        var selector = '' + this._selector + '[data-target="' + target + '"],' + ('' + this._selector + '[href="' + target + '"]');

        // todo (fat): getting all the raw li's up the tree is not great.
        var parentListItems = $(selector).parents(Selector.LI);

        for (var i = parentListItems.length; i--;) {
          $(parentListItems[i]).addClass(ClassName.ACTIVE);

          var itemParent = parentListItems[i].parentNode;

          if (itemParent && $(itemParent).hasClass(ClassName.DROPDOWN_MENU)) {
            var closestDropdown = $(itemParent).closest(Selector.LI_DROPDOWN)[0];
            $(closestDropdown).addClass(ClassName.ACTIVE);
          }
        }

        $(this._scrollElement).trigger(Event.ACTIVATE, {
          relatedTarget: target
        });
      }
    }, {
      key: '_clear',
      value: function _clear() {
        var activeParents = $(this._selector).parentsUntil(this._config.target, Selector.ACTIVE);

        for (var i = activeParents.length; i--;) {
          $(activeParents[i]).removeClass(ClassName.ACTIVE);
        }
      }
    }], [{
      key: 'VERSION',

      // getters

      get: function () {
        return VERSION;
      }
    }, {
      key: 'Default',
      get: function () {
        return Default;
      }
    }, {
      key: '_jQueryInterface',

      // static

      value: function _jQueryInterface(config) {
        return this.each(function () {
          var data = $(this).data(DATA_KEY);
          var _config = typeof config === 'object' && config || null;

          if (!data) {
            data = new ScrollSpy(this, _config);
            $(this).data(DATA_KEY, data);
          }

          if (typeof config === 'string') {
            data[config]();
          }
        });
      }
    }]);

    return ScrollSpy;
  })();

  /**
   * ------------------------------------------------------------------------
   * Data Api implementation
   * ------------------------------------------------------------------------
   */

  $(window).on(Event.LOAD_DATA_API, function () {
    var scrollSpys = $.makeArray($(Selector.DATA_SPY));

    for (var i = scrollSpys.length; i--;) {
      var $spy = $(scrollSpys[i]);
      ScrollSpy._jQueryInterface.call($spy, $spy.data());
    }
  });

  /**
   * ------------------------------------------------------------------------
   * jQuery
   * ------------------------------------------------------------------------
   */

  $.fn[NAME] = ScrollSpy._jQueryInterface;
  $.fn[NAME].Constructor = ScrollSpy;
  $.fn[NAME].noConflict = function () {
    $.fn[NAME] = JQUERY_NO_CONFLICT;
    return ScrollSpy._jQueryInterface;
  };

  return ScrollSpy;
})(jQuery);
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