foundation.dropdown.js

import $ from 'jquery';
import { Keyboard } from './foundation.util.keyboard';
import { GetYoDigits, ignoreMousedisappear } from './foundation.core.utils';
import { Positionable } from './foundation.positionable';

import { Triggers } from './foundation.util.triggers';
import { Touch } from './foundation.util.touch'

/**
 * Dropdown module.
 * @module foundation.dropdown
 * @requires foundation.util.keyboard
 * @requires foundation.util.box
 * @requires foundation.util.touch
 * @requires foundation.util.triggers
 */
class Dropdown extends Positionable {
  /**
   * Creates a new instance of a dropdown.
   * @class
   * @name Dropdown
   * @param {jQuery} element - jQuery object to make into a dropdown.
   *        Object should be of the dropdown panel, rather than its anchor.
   * @param {Object} options - Overrides to the default plugin settings.
   */
  _setup(element, options) {
    this.$element = element;
    this.options = $.extend({}, Dropdown.defaults, this.$element.data(), options);
    this.className = 'Dropdown'; // ie9 back compat

    // Touch and Triggers init are idempotent, just need to make sure they are initialized
    Touch.init($);
    Triggers.init($);

    this._init();

    Keyboard.register('Dropdown', {
      'ENTER': 'toggle',
      'SPACE': 'toggle',
      'ESCAPE': 'close'
    });
  }

  /**
   * Initializes the plugin by setting/checking options and attributes, adding helper variables, and saving the anchor.
   * @function
   * @private
   */
  _init() {
    var $id = this.$element.attr('id');

    this.$anchors = $(`[data-toggle="${$id}"]`).length ? $(`[data-toggle="${$id}"]`) : $(`[data-open="${$id}"]`);
    this.$anchors.attr({
      'aria-controls': $id,
      'data-is-focus': false,
      'data-yeti-box': $id,
      'aria-haspopup': true,
      'aria-expanded': false
    });

    this._setCurrentAnchor(this.$anchors.first());

    if(this.options.parentClass){
      this.$parent = this.$element.parents('.' + this.options.parentClass);
    }else{
      this.$parent = null;
    }

    // Set [aria-labelledby] on the Dropdown if it is not set
    if (typeof this.$element.attr('aria-labelledby') === 'undefined') {
      // Get the anchor ID or create one
      if (typeof this.$currentAnchor.attr('id') === 'undefined') {
        this.$currentAnchor.attr('id', GetYoDigits(6, 'dd-anchor'));
      }

      this.$element.attr('aria-labelledby', this.$currentAnchor.attr('id'));
    }

    this.$element.attr({
      'aria-hidden': 'true',
      'data-yeti-box': $id,
      'data-resize': $id,
    });
    
  if (this.options.position !== 'auto') {
  this.position = this.options.position;
  } else {
  this.position = this._getDefaultPosition();
  }

  if (this.options.alignment !== 'auto') {
  this.alignment = this.options.alignment;
  } else {
  this.alignment = this._getDefaultAlignment();
  }

    super._init();
    this._events();
  }

  _getDefaultPosition() {
    // handle legacy classnames
    var position = this.$element[0].className.match(/(top|left|right|bottom)/g);
    if(position) {
      return position[0];
    } else {
      return 'bottom'
    }
  }

  _getDefaultAlignment() {
    // handle legacy float approach
    var horizontalPosition = /float-(\S+)/.exec(this.$currentAnchor.attr('class'));
    if(horizontalPosition) {
      return horizontalPosition[1];
    }

    return super._getDefaultAlignment();
  }



  /**
   * Sets the position and orientation of the dropdown pane, checks for collisions if allow-overlap is not true.
   * Recursively calls itself if a collision is detected, with a new position class.
   * @function
   * @private
   */
  _setPosition() {
    this.$element.removeClass(`has-position-${this.position} has-alignment-${this.alignment}`);
    // Override default _setPosition logic to handle explicit position + fallback alignment
const position = this.position;
const alignment = this.alignment;

// Use Positionable utility to get the best possible position
const offsets = Foundation.Box.GetOffsets(this.$element, this.$currentAnchor, this.options, this.$parent);

// Check for collision using the explicit position
const collision = Foundation.Box.ImNotTouchingYou(this.$element, this.$parent);

// If there is a collision and position is explicitly set
if (!collision && this.options.position !== 'auto') {
  // Try changing only alignment
  const altAlignments = ['left', 'right', 'center'].filter(a => a !== alignment);
  for (let newAlignment of altAlignments) {
    this.alignment = newAlignment;

    // Reposition with new alignment
    super._setPosition(this.$currentAnchor, this.$element, this.$parent);
    if (Foundation.Box.ImNotTouchingYou(this.$element, this.$parent)) {
      break;
    }
  }
} else {
  // Let Foundation decide when position is auto or there's no collision
  super._setPosition(this.$currentAnchor, this.$element, this.$parent);
}

    this.$element.addClass(`has-position-${this.position} has-alignment-${this.alignment}`);
  }

  /**
   * Make it a current anchor.
   * Current anchor as the reference for the position of Dropdown panes.
   * @param {HTML} el - DOM element of the anchor.
   * @function
   * @private
   */
  _setCurrentAnchor(el) {
    this.$currentAnchor = $(el);
  }

  /**
   * Adds event listeners to the element utilizing the triggers utility library.
   * @function
   * @private
   */
  _events() {
    var _this = this,
        hasTouch = 'ontouchstart' in window || (typeof window.ontouchstart !== 'undefined');

    this.$element.on({
      'open.zf.trigger': this.open.bind(this),
      'close.zf.trigger': this.close.bind(this),
      'toggle.zf.trigger': this.toggle.bind(this),
      'resizeme.zf.trigger': this._setPosition.bind(this)
    });

    this.$anchors.off('click.zf.trigger')
      .on('click.zf.trigger', function(e) {
        _this._setCurrentAnchor(this);

        if (
          // if forceFollow false, always prevent default action
          (_this.options.forceFollow === false) ||
          // if forceFollow true and hover option true, only prevent default action on 1st click
          // on 2nd click (dropown opened) the default action (e.g. follow a href) gets executed
          (hasTouch && _this.options.hover && _this.$element.hasClass('is-open') === false)
        ) {
          e.preventDefault();
        }
    });

    if(this.options.hover){
      this.$anchors.off('mouseenter.zf.dropdown mouseleave.zf.dropdown')
      .on('mouseenter.zf.dropdown', function(){
        _this._setCurrentAnchor(this);

        var bodyData = $('body').data();
        if(typeof(bodyData.whatinput) === 'undefined' || bodyData.whatinput === 'mouse') {
          clearTimeout(_this.timeout);
          _this.timeout = setTimeout(function(){
            _this.open();
            _this.$anchors.data('hover', true);
          }, _this.options.hoverDelay);
        }
      }).on('mouseleave.zf.dropdown', ignoreMousedisappear(function(){
        clearTimeout(_this.timeout);
        _this.timeout = setTimeout(function(){
          _this.close();
          _this.$anchors.data('hover', false);
        }, _this.options.hoverDelay);
      }));
      if(this.options.hoverPane){
        this.$element.off('mouseenter.zf.dropdown mouseleave.zf.dropdown')
            .on('mouseenter.zf.dropdown', function(){
              clearTimeout(_this.timeout);
            }).on('mouseleave.zf.dropdown', ignoreMousedisappear(function(){
              clearTimeout(_this.timeout);
              _this.timeout = setTimeout(function(){
                _this.close();
                _this.$anchors.data('hover', false);
              }, _this.options.hoverDelay);
            }));
      }
    }
    this.$anchors.add(this.$element).on('keydown.zf.dropdown', function(e) {

      var $target = $(this);

      Keyboard.handleKey(e, 'Dropdown', {
        open: function() {
          if ($target.is(_this.$anchors) && !$target.is('input, textarea')) {
            _this.open();
            _this.$element.attr('tabindex', -1).focus();
            e.preventDefault();
          }
        },
        close: function() {
          _this.close();
          _this.$anchors.focus();
        }
      });
    });
  }

  /**
   * Adds an event handler to the body to close any dropdowns on a click.
   * @function
   * @private
   */
  _addBodyHandler() {
     var $body = $(document.body).not(this.$element),
         _this = this;
     $body.off('click.zf.dropdown tap.zf.dropdown')
          .on('click.zf.dropdown tap.zf.dropdown', function (e) {
            if(_this.$anchors.is(e.target) || _this.$anchors.find(e.target).length) {
              return;
            }
            if(_this.$element.is(e.target) || _this.$element.find(e.target).length) {
              return;
            }
            _this.close();
            $body.off('click.zf.dropdown tap.zf.dropdown');
          });
  }

  /**
   * Opens the dropdown pane, and fires a bubbling event to close other dropdowns.
   * @function
   * @fires Dropdown#closeme
   * @fires Dropdown#show
   */
  open() {
    // var _this = this;
    /**
     * Fires to close other open dropdowns, typically when dropdown is opening
     * @event Dropdown#closeme
     */
    this.$element.trigger('closeme.zf.dropdown', this.$element.attr('id'));
    this.$anchors.addClass('hover')
        .attr({'aria-expanded': true});
    // this.$element/*.show()*/;

    this.$element.addClass('is-opening');
    this._setPosition();
    this.$element.removeClass('is-opening').addClass('is-open')
        .attr({'aria-hidden': false});

    if(this.options.autoFocus){
      var $focusable = Keyboard.findFocusable(this.$element);
      if($focusable.length){
        $focusable.eq(0).focus();
      }
    }

    if(this.options.closeOnClick){ this._addBodyHandler(); }

    if (this.options.trapFocus) {
      Keyboard.trapFocus(this.$element);
    }

    /**
     * Fires once the dropdown is visible.
     * @event Dropdown#show
     */
    this.$element.trigger('show.zf.dropdown', [this.$element]);
  }

  /**
   * Closes the open dropdown pane.
   * @function
   * @fires Dropdown#hide
   */
  close() {
    if(!this.$element.hasClass('is-open')){
      return false;
    }
    this.$element.removeClass('is-open')
        .attr({'aria-hidden': true});

    this.$anchors.removeClass('hover')
        .attr('aria-expanded', false);

    /**
     * Fires once the dropdown is no longer visible.
     * @event Dropdown#hide
     */
    this.$element.trigger('hide.zf.dropdown', [this.$element]);

    if (this.options.trapFocus) {
      Keyboard.releaseFocus(this.$element);
    }
  }

  /**
   * Toggles the dropdown pane's visibility.
   * @function
   */
  toggle() {
    if(this.$element.hasClass('is-open')){
      if(this.$anchors.data('hover')) return;
      this.close();
    }else{
      this.open();
    }
  }

  /**
   * Destroys the dropdown.
   * @function
   */
  _destroy() {
    this.$element.off('.zf.trigger').hide();
    this.$anchors.off('.zf.dropdown');
    $(document.body).off('click.zf.dropdown tap.zf.dropdown');

  }
}

Dropdown.defaults = {
  /**
   * Class that designates bounding container of Dropdown (default: window)
   * @option
   * @type {?string}
   * @default null
   */
  parentClass: null,
  /**
   * Amount of time to delay opening a submenu on hover event.
   * @option
   * @type {number}
   * @default 250
   */
  hoverDelay: 250,
  /**
   * Allow submenus to open on hover events
   * @option
   * @type {boolean}
   * @default false
   */
  hover: false,
  /**
   * Don't close dropdown when hovering over dropdown pane
   * @option
   * @type {boolean}
   * @default false
   */
  hoverPane: false,
  /**
   * Number of pixels between the dropdown pane and the triggering element on open.
   * @option
   * @type {number}
   * @default 0
   */
  vOffset: 0,
  /**
   * Number of pixels between the dropdown pane and the triggering element on open.
   * @option
   * @type {number}
   * @default 0
   */
  hOffset: 0,
  /**
   * Position of dropdown. Can be left, right, bottom, top, or auto.
   * @option
   * @type {string}
   * @default 'auto'
   */
  position: 'auto',
  /**
   * Alignment of dropdown relative to anchor. Can be left, right, bottom, top, center, or auto.
   * @option
   * @type {string}
   * @default 'auto'
   */
  alignment: 'auto',
  /**
   * Allow overlap of container/window. If false, dropdown will first try to position as defined by data-position and data-alignment, but reposition if it would cause an overflow.
   * @option
   * @type {boolean}
   * @default false
   */
  allowOverlap: false,
  /**
   * Allow overlap of only the bottom of the container. This is the most common
   * behavior for dropdowns, allowing the dropdown to extend the bottom of the
   * screen but not otherwise influence or break out of the container.
   * @option
   * @type {boolean}
   * @default true
   */
  allowBottomOverlap: true,
  /**
   * Allow the plugin to trap focus to the dropdown pane if opened with keyboard commands.
   * @option
   * @type {boolean}
   * @default false
   */
  trapFocus: false,
  /**
   * Allow the plugin to set focus to the first focusable element within the pane, regardless of method of opening.
   * @option
   * @type {boolean}
   * @default false
   */
  autoFocus: false,
  /**
   * Allows a click on the body to close the dropdown.
   * @option
   * @type {boolean}
   * @default false
   */
  closeOnClick: false,
  /**
   * If true the default action of the toggle (e.g. follow a link with href) gets executed on click. If hover option is also true the default action gets prevented on first click for mobile / touch devices and executed on second click.
   * @option
   * @type {boolean}
   * @default true
   */
  forceFollow: true
};

export {Dropdown};