bootstrap-vue/esm/mixins/dropdown.js

BootstrapVue, with over 40 plugins and more than 80 custom components, provides one of the most comprehensive implementations of Bootstrap v4 components and grid system for Vue.js. With extensive and automated WAI-ARIA accessibility markup.

function ownKeys(object, enumerableOnly) { var keys = Object.keys(object); if (Object.getOwnPropertySymbols) { var symbols = Object.getOwnPropertySymbols(object); if (enumerableOnly) symbols = symbols.filter(function (sym) { return Object.getOwnPropertyDescriptor(object, sym).enumerable; }); keys.push.apply(keys, symbols); } return keys; }

function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i] != null ? arguments[i] : {}; if (i % 2) { ownKeys(source, true).forEach(function (key) { _defineProperty(target, key, source[key]); }); } else if (Object.getOwnPropertyDescriptors) { Object.defineProperties(target, Object.getOwnPropertyDescriptors(source)); } else { ownKeys(source).forEach(function (key) { Object.defineProperty(target, key, Object.getOwnPropertyDescriptor(source, key)); }); } } return target; }

function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }

import Popper from 'popper.js';
import KeyCodes from '../utils/key-codes';
import warn from '../utils/warn';
import { BvEvent } from '../utils/bv-event.class';
import { closest, contains, isVisible, requestAF, selectAll } from '../utils/dom';
import { hasTouchSupport } from '../utils/env';
import { isNull } from '../utils/inspect';
import clickOutMixin from './click-out';
import focusInMixin from './focus-in';
import idMixin from './id'; // Return an array of visible items

var filterVisibles = function filterVisibles(els) {
  return (els || []).filter(isVisible);
}; // Root dropdown event names


var ROOT_DROPDOWN_PREFIX = 'bv::dropdown::';
var ROOT_DROPDOWN_SHOWN = "".concat(ROOT_DROPDOWN_PREFIX, "shown");
var ROOT_DROPDOWN_HIDDEN = "".concat(ROOT_DROPDOWN_PREFIX, "hidden"); // Delay when loosing focus before closing menu (in ms)

var FOCUSOUT_DELAY = hasTouchSupport ? 450 : 150; // Dropdown item CSS selectors

var Selector = {
  FORM_CHILD: '.dropdown form',
  ITEM_SELECTOR: ['.dropdown-item', '.b-dropdown-form'].map(function (selector) {
    return "".concat(selector, ":not(.disabled):not([disabled])");
  }).join(', ')
}; // Popper attachment positions

var AttachmentMap = {
  // Dropup left align
  TOP: 'top-start',
  // Dropup right align
  TOPEND: 'top-end',
  // Dropdown left align
  BOTTOM: 'bottom-start',
  // Dropdown right align
  BOTTOMEND: 'bottom-end',
  // Dropright left align
  RIGHT: 'right-start',
  // Dropright right align
  RIGHTEND: 'right-end',
  // Dropleft left align
  LEFT: 'left-start',
  // Dropleft right align
  LEFTEND: 'left-end'
}; // @vue/component

export default {
  mixins: [idMixin, clickOutMixin, focusInMixin],
  provide: function provide() {
    return {
      bvDropdown: this
    };
  },
  props: {
    disabled: {
      type: Boolean,
      default: false
    },
    text: {
      // Button label
      type: String,
      default: ''
    },
    html: {
      // Button label
      type: String
    },
    dropup: {
      // place on top if possible
      type: Boolean,
      default: false
    },
    dropright: {
      // place right if possible
      type: Boolean,
      default: false
    },
    dropleft: {
      // place left if possible
      type: Boolean,
      default: false
    },
    right: {
      // Right align menu (default is left align)
      type: Boolean,
      default: false
    },
    offset: {
      // Number of pixels to offset menu, or a CSS unit value (i.e. 1px, 1rem, etc)
      type: [Number, String],
      default: 0
    },
    noFlip: {
      // Disable auto-flipping of menu from bottom<=>top
      type: Boolean,
      default: false
    },
    lazy: {
      // If true, only render menu contents when open
      type: Boolean,
      default: false
    },
    popperOpts: {
      // type: Object,
      default: function _default() {}
    }
  },
  data: function data() {
    return {
      visible: false,
      inNavbar: null,
      visibleChangePrevented: false
    };
  },
  computed: {
    toggler: function toggler() {
      var toggle = this.$refs.toggle;
      return toggle ? toggle.$el || toggle : null;
    },
    directionClass: function directionClass() {
      if (this.dropup) {
        return 'dropup';
      } else if (this.dropright) {
        return 'dropright';
      } else if (this.dropleft) {
        return 'dropleft';
      }

      return '';
    }
  },
  watch: {
    visible: function visible(newValue, oldValue) {
      if (this.visibleChangePrevented) {
        this.visibleChangePrevented = false;
        return;
      }

      if (newValue !== oldValue) {
        var evtName = newValue ? 'show' : 'hide';
        var bvEvt = new BvEvent(evtName, {
          cancelable: true,
          vueTarget: this,
          target: this.$refs.menu,
          relatedTarget: null,
          componentId: this.safeId ? this.safeId() : this.id || null
        });
        this.emitEvent(bvEvt);

        if (bvEvt.defaultPrevented) {
          // Reset value and exit if canceled
          this.visibleChangePrevented = true;
          this.visible = oldValue; // Just in case a child element triggered this.hide(true)

          this.$off('hidden', this.focusToggler);
          return;
        }

        if (evtName === 'show') {
          this.showMenu();
        } else {
          this.hideMenu();
        }
      }
    },
    disabled: function disabled(newValue, oldValue) {
      if (newValue !== oldValue && newValue && this.visible) {
        // Hide dropdown if disabled changes to true
        this.visible = false;
      }
    }
  },
  created: function created() {
    // Create non-reactive property
    this.$_popper = null;
    this.$_hideTimeout = null;

    this.$_noop = function () {};
  },
  deactivated: function deactivated()
  /* istanbul ignore next: not easy to test */
  {
    // In case we are inside a `<keep-alive>`
    this.visible = false;
    this.whileOpenListen(false);
    this.destroyPopper();
  },
  beforeDestroy: function beforeDestroy() {
    this.visible = false;
    this.whileOpenListen(false);
    this.destroyPopper();
    this.clearHideTimeout();
  },
  methods: {
    // Event emitter
    emitEvent: function emitEvent(bvEvt) {
      var type = bvEvt.type;
      this.$emit(type, bvEvt);
      this.$root.$emit("".concat(ROOT_DROPDOWN_PREFIX).concat(type), bvEvt);
    },
    showMenu: function showMenu() {
      var _this = this;

      if (this.disabled) {
        /* istanbul ignore next */
        return;
      } // Are we in a navbar ?


      if (isNull(this.inNavbar) && this.isNav) {
        // We should use an injection for this

        /* istanbul ignore next */
        this.inNavbar = Boolean(closest('.navbar', this.$el));
      } // Disable totally Popper.js for Dropdown in Navbar


      if (!this.inNavbar) {
        if (typeof Popper === 'undefined') {
          /* istanbul ignore next */
          warn('b-dropdown: Popper.js not found. Falling back to CSS positioning.');
        } else {
          // for dropup with alignment we use the parent element as popper container
          var element = this.dropup && this.right || this.split ? this.$el : this.$refs.toggle; // Make sure we have a reference to an element, not a component!

          element = element.$el || element; // Instantiate popper.js

          this.createPopper(element);
        }
      } // Ensure other menus are closed


      this.$root.$emit(ROOT_DROPDOWN_SHOWN, this);
      this.whileOpenListen(true); // Wrap in nextTick to ensure menu is fully rendered/shown

      this.$nextTick(function () {
        // Focus on the menu container on show
        _this.focusMenu(); // Emit the shown event


        _this.$emit('shown');
      });
    },
    hideMenu: function hideMenu() {
      this.whileOpenListen(false);
      this.$root.$emit(ROOT_DROPDOWN_HIDDEN, this);
      this.$emit('hidden');
      this.destroyPopper();
    },
    createPopper: function createPopper(element) {
      this.destroyPopper();
      this.$_popper = new Popper(element, this.$refs.menu, this.getPopperConfig());
    },
    destroyPopper: function destroyPopper() {
      if (this.$_popper) {
        // Ensure popper event listeners are removed cleanly
        this.$_popper.destroy();
      }

      this.$_popper = null;
    },
    clearHideTimeout: function clearHideTimeout() {
      /* istanbul ignore next */
      if (this.$_hideTimeout) {
        clearTimeout(this.$_hideTimeout);
        this.$_hideTimeout = null;
      }
    },
    getPopperConfig: function getPopperConfig() {
      var placement = AttachmentMap.BOTTOM;

      if (this.dropup) {
        placement = this.right ? AttachmentMap.TOPEND : AttachmentMap.TOP;
      } else if (this.dropright) {
        placement = AttachmentMap.RIGHT;
      } else if (this.dropleft) {
        placement = AttachmentMap.LEFT;
      } else if (this.right) {
        placement = AttachmentMap.BOTTOMEND;
      }

      var popperConfig = {
        placement: placement,
        modifiers: {
          offset: {
            offset: this.offset || 0
          },
          flip: {
            enabled: !this.noFlip
          }
        }
      };

      if (this.boundary) {
        popperConfig.modifiers.preventOverflow = {
          boundariesElement: this.boundary
        };
      }

      return _objectSpread({}, popperConfig, {}, this.popperOpts || {});
    },
    // Turn listeners on/off while open
    whileOpenListen: function whileOpenListen(isOpen) {
      // Hide the dropdown when clicked outside
      this.listenForClickOut = isOpen; // Hide the dropdown when it loses focus

      this.listenForFocusIn = isOpen; // Hide the dropdown when another dropdown is opened

      var method = isOpen ? '$on' : '$off';
      this.$root[method](ROOT_DROPDOWN_SHOWN, this.rootCloseListener);
    },
    rootCloseListener: function rootCloseListener(vm) {
      if (vm !== this) {
        this.visible = false;
      }
    },
    show: function show() {
      var _this2 = this;

      // Public method to show dropdown
      if (this.disabled) {
        return;
      } // Wrap in a requestAnimationFrame to allow any previous
      // click handling to occur first


      requestAF(function () {
        _this2.visible = true;
      });
    },
    hide: function hide() {
      var refocus = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : false;

      // Public method to hide dropdown
      if (this.disabled) {
        /* istanbul ignore next */
        return;
      }

      this.visible = false;

      if (refocus) {
        // Child element is closing the dropdown on click
        this.$once('hidden', this.focusToggler);
      }
    },
    // Called only by a button that toggles the menu
    toggle: function toggle(evt) {
      evt = evt || {};
      var type = evt.type;
      var key = evt.keyCode;

      if (type !== 'click' && !(type === 'keydown' && (key === KeyCodes.ENTER || key === KeyCodes.SPACE || key === KeyCodes.DOWN))) {
        // We only toggle on Click, Enter, Space, and Arrow Down

        /* istanbul ignore next */
        return;
      }
      /* istanbul ignore next */


      if (this.disabled) {
        this.visible = false;
        return;
      }

      this.$emit('toggle', evt);
      evt.preventDefault();
      evt.stopPropagation(); // Toggle visibility

      if (this.visible) {
        this.hide(true);
      } else {
        this.show();
      }
    },
    // Called only in split button mode, for the split button
    click: function click(evt) {
      /* istanbul ignore next */
      if (this.disabled) {
        this.visible = false;
        return;
      }

      this.$emit('click', evt);
    },
    // Called from dropdown menu context
    onKeydown: function onKeydown(evt) {
      var key = evt.keyCode;

      if (key === KeyCodes.ESC) {
        // Close on ESC
        this.onEsc(evt);
      } else if (key === KeyCodes.DOWN) {
        // Down Arrow
        this.focusNext(evt, false);
      } else if (key === KeyCodes.UP) {
        // Up Arrow
        this.focusNext(evt, true);
      }
    },
    // If uses presses ESC to close menu
    onEsc: function onEsc(evt) {
      if (this.visible) {
        this.visible = false;
        evt.preventDefault();
        evt.stopPropagation(); // Return focus to original trigger button

        this.$once('hidden', this.focusToggler);
      }
    },
    // Document click out listener
    clickOutHandler: function clickOutHandler(evt) {
      var _this3 = this;

      var target = evt.target;

      if (this.visible && !contains(this.$refs.menu, target) && !contains(this.toggler, target)) {
        var doHide = function doHide() {
          _this3.visible = false;
          return null;
        }; // When we are in a navbar (which has been responsively stacked), we
        // delay the dropdown's closing so that the next element has a chance
        // to have it's click handler fired (in case it's position moves on
        // the screen do to a navbar menu above it collapsing)
        // https://github.com/bootstrap-vue/bootstrap-vue/issues/4113


        this.clearHideTimeout();
        this.$_hideTimeout = this.inNavbar ? setTimeout(doHide, FOCUSOUT_DELAY) : doHide();
      }
    },
    // Document focusin listener
    focusInHandler: function focusInHandler(evt) {
      // Shared logic with click-out handler
      this.clickOutHandler(evt);
    },
    // Keyboard nav
    focusNext: function focusNext(evt, up) {
      var _this4 = this;

      // Ignore key up/down on form elements
      if (!this.visible || evt && closest(Selector.FORM_CHILD, evt.target)) {
        /* istanbul ignore next: should never happen */
        return;
      }

      evt.preventDefault();
      evt.stopPropagation();
      this.$nextTick(function () {
        var items = _this4.getItems();

        if (items.length < 1) {
          /* istanbul ignore next: should never happen */
          return;
        }

        var index = items.indexOf(evt.target);

        if (up && index > 0) {
          index--;
        } else if (!up && index < items.length - 1) {
          index++;
        }

        if (index < 0) {
          /* istanbul ignore next: should never happen */
          index = 0;
        }

        _this4.focusItem(index, items);
      });
    },
    focusItem: function focusItem(idx, items) {
      var el = items.find(function (el, i) {
        return i === idx;
      });

      if (el && el.focus) {
        el.focus();
      }
    },
    getItems: function getItems() {
      // Get all items
      return filterVisibles(selectAll(Selector.ITEM_SELECTOR, this.$refs.menu));
    },
    focusMenu: function focusMenu() {
      this.$refs.menu.focus && this.$refs.menu.focus();
    },
    focusToggler: function focusToggler() {
      var _this5 = this;

      this.$nextTick(function () {
        var toggler = _this5.toggler;

        if (toggler && toggler.focus) {
          toggler.focus();
        }
      });
    }
  }
};