carbon-components/es/components/dropdown/dropdown.js

function _typeof(obj) {
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      return typeof obj;
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    _typeof = function _typeof(obj) {
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  return _typeof(obj);
}

function _classCallCheck(instance, Constructor) {
  if (!(instance instanceof Constructor)) {
    throw new TypeError("Cannot call a class as a function");
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function _defineProperties(target, props) {
  for (var i = 0; i < props.length; i++) {
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    descriptor.configurable = true;
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    Object.defineProperty(target, descriptor.key, descriptor);
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}

function _createClass(Constructor, protoProps, staticProps) {
  if (protoProps) _defineProperties(Constructor.prototype, protoProps);
  if (staticProps) _defineProperties(Constructor, staticProps);
  return Constructor;
}

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  if (call && (_typeof(call) === "object" || typeof call === "function")) {
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  return _assertThisInitialized(self);
}

function _assertThisInitialized(self) {
  if (self === void 0) {
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  return self;
}

function _getPrototypeOf(o) {
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    return o.__proto__ || Object.getPrototypeOf(o);
  };
  return _getPrototypeOf(o);
}

function _inherits(subClass, superClass) {
  if (typeof superClass !== "function" && superClass !== null) {
    throw new TypeError("Super expression must either be null or a function");
  }

  subClass.prototype = Object.create(superClass && superClass.prototype, {
    constructor: {
      value: subClass,
      writable: true,
      configurable: true
    }
  });
  if (superClass) _setPrototypeOf(subClass, superClass);
}

function _setPrototypeOf(o, p) {
  _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) {
    o.__proto__ = p;
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  return _setPrototypeOf(o, p);
}
/**
 * Copyright IBM Corp. 2016, 2018
 *
 * This source code is licensed under the Apache-2.0 license found in the
 * LICENSE file in the root directory of this source tree.
 */


import settings from '../../globals/js/settings';
import mixin from '../../globals/js/misc/mixin';
import createComponent from '../../globals/js/mixins/create-component';
import initComponentBySearch from '../../globals/js/mixins/init-component-by-search';
import trackBlur from '../../globals/js/mixins/track-blur';
import eventMatches from '../../globals/js/misc/event-matches';
import on from '../../globals/js/misc/on';

var toArray = function toArray(arrayLike) {
  return Array.prototype.slice.call(arrayLike);
};

var Dropdown =
/*#__PURE__*/
function (_mixin) {
  _inherits(Dropdown, _mixin);
  /**
   * A selector with drop downs.
   * @extends CreateComponent
   * @extends InitComponentBySearch
   * @extends TrackBlur
   * @param {HTMLElement} element The element working as a selector.
   * @param {Object} [options] The component options.
   * @param {string} [options.selectorItem] The CSS selector to find clickable areas in dropdown items.
   * @param {string} [options.selectorItemSelected] The CSS selector to find the clickable area in the selected dropdown item.
   * @param {string} [options.classSelected] The CSS class for the selected dropdown item.
   * @param {string} [options.classOpen] The CSS class for the open state.
   * @param {string} [options.classDisabled] The CSS class for the disabled state.
   * @param {string} [options.eventBeforeSelected]
   *   The name of the custom event fired before a drop down item is selected.
   *   Cancellation of this event stops selection of drop down item.
   * @param {string} [options.eventAfterSelected] The name of the custom event fired after a drop down item is selected.
   */


  function Dropdown(element, options) {
    var _this;

    _classCallCheck(this, Dropdown);

    _this = _possibleConstructorReturn(this, _getPrototypeOf(Dropdown).call(this, element, options));

    _this.manage(on(_this.element.ownerDocument, 'click', function (event) {
      _this._toggle(event);
    }));

    _this.manage(on(_this.element, 'keydown', function (event) {
      _this._handleKeyDown(event);
    }));

    _this.manage(on(_this.element, 'click', function (event) {
      var item = eventMatches(event, _this.options.selectorItem);

      if (item) {
        _this.select(item);
      }
    }));

    return _this;
  }
  /**
   * Handles keydown event.
   * @param {Event} event The event triggering this method.
   */


  _createClass(Dropdown, [{
    key: "_handleKeyDown",
    value: function _handleKeyDown(event) {
      var isOpen = this.element.classList.contains(this.options.classOpen);
      var direction = {
        38: this.constructor.NAVIGATE.BACKWARD,
        40: this.constructor.NAVIGATE.FORWARD
      }[event.which];

      if (isOpen && direction !== undefined) {
        this.navigate(direction);
        event.preventDefault(); // Prevents up/down keys from scrolling container
      } else {
        this._toggle(event);
      }
    }
    /**
     * Opens and closes the dropdown menu.
     * @param {Event} [event] The event triggering this method.
     */

  }, {
    key: "_toggle",
    value: function _toggle(event) {
      var _this2 = this;

      var isDisabled = this.element.classList.contains(this.options.classDisabled);

      if (isDisabled) {
        return;
      }

      if ([13, 32, 40].indexOf(event.which) >= 0 && !event.target.matches(this.options.selectorItem) || event.which === 27 || event.type === 'click') {
        var isOpen = this.element.classList.contains(this.options.classOpen);
        var isOfSelf = this.element.contains(event.target);
        var actions = {
          add: isOfSelf && event.which === 40 && !isOpen,
          remove: (!isOfSelf || event.which === 27) && isOpen,
          toggle: isOfSelf && event.which !== 27 && event.which !== 40
        };
        Object.keys(actions).forEach(function (action) {
          if (actions[action]) {
            _this2.element.classList[action](_this2.options.classOpen);

            _this2.element.focus();
          }
        });
        var listItems = toArray(this.element.querySelectorAll(this.options.selectorItem));
        listItems.forEach(function (item) {
          if (_this2.element.classList.contains(_this2.options.classOpen)) {
            item.tabIndex = 0;
          } else {
            item.tabIndex = -1;
          }
        });
      }
    }
    /**
     * @returns {Element} Currently highlighted element.
     */

  }, {
    key: "getCurrentNavigation",
    value: function getCurrentNavigation() {
      var focused = this.element.ownerDocument.activeElement;
      return focused.nodeType === Node.ELEMENT_NODE && focused.matches(this.options.selectorItem) ? focused : null;
    }
    /**
     * Moves up/down the focus.
     * @param {number} direction The direction of navigating.
     */

  }, {
    key: "navigate",
    value: function navigate(direction) {
      var items = toArray(this.element.querySelectorAll(this.options.selectorItem));
      var start = this.getCurrentNavigation() || this.element.querySelector(this.options.selectorItemSelected);

      var getNextItem = function getNextItem(old) {
        var handleUnderflow = function handleUnderflow(i, l) {
          return i + (i >= 0 ? 0 : l);
        };

        var handleOverflow = function handleOverflow(i, l) {
          return i - (i < l ? 0 : l);
        }; // `items.indexOf(old)` may be -1 (Scenario of no previous focus)


        var index = Math.max(items.indexOf(old) + direction, -1);
        return items[handleUnderflow(handleOverflow(index, items.length), items.length)];
      };

      for (var current = getNextItem(start); current && current !== start; current = getNextItem(current)) {
        if (!current.matches(this.options.selectorItemHidden) && !current.parentNode.matches(this.options.selectorItemHidden) && !current.matches(this.options.selectorItemSelected)) {
          current.focus();
          break;
        }
      }
    }
    /**
     * Handles clicking on the dropdown options, doing the following:
     * * Change Dropdown text to selected option.
     * * Remove selected option from options when selected.
     * * Emit custom events.
     * @param {HTMLElement} itemToSelect The element to be activated.
     */

  }, {
    key: "select",
    value: function select(itemToSelect) {
      var _this3 = this;

      var eventStart = new CustomEvent(this.options.eventBeforeSelected, {
        bubbles: true,
        cancelable: true,
        detail: {
          item: itemToSelect
        }
      });

      if (this.element.dispatchEvent(eventStart)) {
        if (this.element.dataset.dropdownType !== 'navigation') {
          var selectorText = this.element.dataset.dropdownType !== 'inline' ? this.options.selectorText : this.options.selectorTextInner;
          var text = this.element.querySelector(selectorText);

          if (text) {
            text.innerHTML = itemToSelect.innerHTML;
          }

          itemToSelect.classList.add(this.options.classSelected);
        }

        this.element.dataset.value = itemToSelect.parentElement.dataset.value;
        toArray(this.element.querySelectorAll(this.options.selectorItemSelected)).forEach(function (item) {
          if (itemToSelect !== item) {
            item.classList.remove(_this3.options.classSelected);
          }
        });
        this.element.dispatchEvent(new CustomEvent(this.options.eventAfterSelected, {
          bubbles: true,
          cancelable: true,
          detail: {
            item: itemToSelect
          }
        }));
      }
    }
    /**
     * Closes the dropdown menu if this component loses focus.
     */

  }, {
    key: "handleBlur",
    value: function handleBlur() {
      this.element.classList.remove(this.options.classOpen);
    }
    /**
     * The map associating DOM element and selector instance.
     * @member Dropdown.components
     * @type {WeakMap}
     */

  }], [{
    key: "options",

    /**
     * The component options.
     * If `options` is specified in the constructor, {@linkcode Dropdown.create .create()}, or {@linkcode Dropdown.init .init()},
     * properties in this object are overriden for the instance being create and how {@linkcode Dropdown.init .init()} works.
     * @member Dropdown.options
     * @type {Object}
     * @property {string} selectorInit The CSS selector to find selectors.
     * @property {string} [selectorText] The CSS selector to find the element showing the selected item.
     * @property {string} [selectorTextInner] The CSS selector to find the element showing the selected item, used for inline mode.
     * @property {string} [selectorItem] The CSS selector to find clickable areas in dropdown items.
     * @property {string} [selectorItemHidden]
     *   The CSS selector to find hidden dropdown items.
     *   Used to skip dropdown items for keyboard navigation.
     * @property {string} [selectorItemSelected] The CSS selector to find the clickable area in the selected dropdown item.
     * @property {string} [classSelected] The CSS class for the selected dropdown item.
     * @property {string} [classOpen] The CSS class for the open state.
     * @property {string} [classDisabled] The CSS class for the disabled state.
     * @property {string} [eventBeforeSelected]
     *   The name of the custom event fired before a drop down item is selected.
     *   Cancellation of this event stops selection of drop down item.
     * @property {string} [eventAfterSelected] The name of the custom event fired after a drop down item is selected.
     */
    get: function get() {
      var prefix = settings.prefix;
      return {
        selectorInit: '[data-dropdown]',
        selectorText: ".".concat(prefix, "--dropdown-text"),
        selectorTextInner: ".".concat(prefix, "--dropdown-text__inner"),
        selectorItem: ".".concat(prefix, "--dropdown-link"),
        selectorItemSelected: ".".concat(prefix, "--dropdown--selected"),
        selectorItemHidden: "[hidden],[aria-hidden=\"true\"]",
        classSelected: "".concat(prefix, "--dropdown--selected"),
        classOpen: "".concat(prefix, "--dropdown--open"),
        classDisabled: "".concat(prefix, "--dropdown--disabled"),
        eventBeforeSelected: 'dropdown-beingselected',
        eventAfterSelected: 'dropdown-selected'
      };
    }
    /**
     * Enum for navigating backward/forward.
     * @readonly
     * @member Dropdown.NAVIGATE
     * @type {Object}
     * @property {number} BACKWARD Navigating backward.
     * @property {number} FORWARD Navigating forward.
     */

  }]);

  Dropdown.components = new WeakMap();
  Dropdown.NAVIGATE = {
    BACKWARD: -1,
    FORWARD: 1
  };
  return Dropdown;
}(mixin(createComponent, initComponentBySearch, trackBlur));

export default Dropdown;