scrollspy.js

var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; };

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-alpha.5): 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-alpha.5';
  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,
    method: 'auto',
    target: ''
  };

  var DefaultType = {
    offset: 'number',
    method: 'string',
    target: '(string|element)'
  };

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

  var ClassName = {
    DROPDOWN_ITEM: 'dropdown-item',
    DROPDOWN_MENU: 'dropdown-menu',
    NAV_LINK: 'nav-link',
    NAV: 'nav',
    ACTIVE: 'active'
  };

  var Selector = {
    DATA_SPY: '[data-spy="scroll"]',
    ACTIVE: '.active',
    LIST_ITEM: '.list-item',
    LI: 'li',
    LI_DROPDOWN: 'li.dropdown',
    NAV_LINKS: '.nav-link',
    DROPDOWN: '.dropdown',
    DROPDOWN_ITEMS: '.dropdown-item',
    DROPDOWN_TOGGLE: '.dropdown-toggle'
  };

  var OffsetMethod = {
    OFFSET: 'offset',
    POSITION: 'position'
  };

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

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

      this._element = element;
      this._scrollElement = element.tagName === 'BODY' ? window : element;
      this._config = this._getConfig(config);
      this._selector = this._config.target + ' ' + Selector.NAV_LINKS + ',' + (this._config.target + ' ' + Selector.DROPDOWN_ITEMS);
      this._offsets = [];
      this._targets = [];
      this._activeTarget = null;
      this._scrollHeight = 0;

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

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

    // getters

    // public

    ScrollSpy.prototype.refresh = function refresh() {
      var _this = this;

      var autoMethod = this._scrollElement !== this._scrollElement.window ? OffsetMethod.POSITION : OffsetMethod.OFFSET;

      var offsetMethod = this._config.method === 'auto' ? autoMethod : this._config.method;

      var offsetBase = offsetMethod === OffsetMethod.POSITION ? this._getScrollTop() : 0;

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

      this._scrollHeight = this._getScrollHeight();

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

      targets.map(function (element) {
        var target = void 0;
        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];
        }
        return null;
      }).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]);
      });
    };

    ScrollSpy.prototype.dispose = 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;
    };

    // private

    ScrollSpy.prototype._getConfig = function _getConfig(config) {
      config = $.extend({}, Default, config);

      if (typeof config.target !== 'string') {
        var id = $(config.target).attr('id');
        if (!id) {
          id = Util.getUID(NAME);
          $(config.target).attr('id', id);
        }
        config.target = '#' + id;
      }

      Util.typeCheckConfig(NAME, config, DefaultType);

      return config;
    };

    ScrollSpy.prototype._getScrollTop = function _getScrollTop() {
      return this._scrollElement === window ? this._scrollElement.scrollY : this._scrollElement.scrollTop;
    };

    ScrollSpy.prototype._getScrollHeight = function _getScrollHeight() {
      return this._scrollElement.scrollHeight || Math.max(document.body.scrollHeight, document.documentElement.scrollHeight);
    };

    ScrollSpy.prototype._process = 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]);
        }
      }
    };

    ScrollSpy.prototype._activate = function _activate(target) {
      this._activeTarget = target;

      this._clear();

      var queries = this._selector.split(',');
      queries = queries.map(function (selector) {
        return selector + '[data-target="' + target + '"],' + (selector + '[href="' + target + '"]');
      });

      var $link = $(queries.join(','));

      if ($link.hasClass(ClassName.DROPDOWN_ITEM)) {
        $link.closest(Selector.DROPDOWN).find(Selector.DROPDOWN_TOGGLE).addClass(ClassName.ACTIVE);
        $link.addClass(ClassName.ACTIVE);
      } else {
        // todo (fat) this is kinda sus...
        // recursively add actives to tested nav-links
        $link.parents(Selector.LI).find(Selector.NAV_LINKS).addClass(ClassName.ACTIVE);
      }

      $(this._scrollElement).trigger(Event.ACTIVATE, {
        relatedTarget: target
      });
    };

    ScrollSpy.prototype._clear = function _clear() {
      $(this._selector).filter(Selector.ACTIVE).removeClass(ClassName.ACTIVE);
    };

    // static

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

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

        if (typeof config === 'string') {
          if (data[config] === undefined) {
            throw new Error('No method named "' + config + '"');
          }
          data[config]();
        }
      });
    };

    _createClass(ScrollSpy, null, [{
      key: 'VERSION',
      get: function get() {
        return VERSION;
      }
    }, {
      key: 'Default',
      get: function get() {
        return Default;
      }
    }]);

    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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