@material-ui/core/es/MenuList/MenuList.js

React components that implement Google's Material Design.

import _extends from "@babel/runtime/helpers/esm/extends";
import _objectWithoutPropertiesLoose from "@babel/runtime/helpers/esm/objectWithoutPropertiesLoose";
import * as React from 'react';
import { isFragment } from 'react-is';
import PropTypes from 'prop-types';
import * as ReactDOM from 'react-dom';
import ownerDocument from '../utils/ownerDocument';
import List from '../List';
import getScrollbarSize from '../utils/getScrollbarSize';
import useForkRef from '../utils/useForkRef';

function nextItem(list, item, disableListWrap) {
  if (list === item) {
    return list.firstChild;
  }

  if (item && item.nextElementSibling) {
    return item.nextElementSibling;
  }

  return disableListWrap ? null : list.firstChild;
}

function previousItem(list, item, disableListWrap) {
  if (list === item) {
    return disableListWrap ? list.firstChild : list.lastChild;
  }

  if (item && item.previousElementSibling) {
    return item.previousElementSibling;
  }

  return disableListWrap ? null : list.lastChild;
}

function textCriteriaMatches(nextFocus, textCriteria) {
  if (textCriteria === undefined) {
    return true;
  }

  let text = nextFocus.innerText;

  if (text === undefined) {
    // jsdom doesn't support innerText
    text = nextFocus.textContent;
  }

  text = text.trim().toLowerCase();

  if (text.length === 0) {
    return false;
  }

  if (textCriteria.repeating) {
    return text[0] === textCriteria.keys[0];
  }

  return text.indexOf(textCriteria.keys.join('')) === 0;
}

function moveFocus(list, currentFocus, disableListWrap, disabledItemsFocusable, traversalFunction, textCriteria) {
  let wrappedOnce = false;
  let nextFocus = traversalFunction(list, currentFocus, currentFocus ? disableListWrap : false);

  while (nextFocus) {
    // Prevent infinite loop.
    if (nextFocus === list.firstChild) {
      if (wrappedOnce) {
        return;
      }

      wrappedOnce = true;
    } // Same logic as useAutocomplete.js


    const nextFocusDisabled = disabledItemsFocusable ? false : nextFocus.disabled || nextFocus.getAttribute('aria-disabled') === 'true';

    if (!nextFocus.hasAttribute('tabindex') || !textCriteriaMatches(nextFocus, textCriteria) || nextFocusDisabled) {
      // Move to the next element.
      nextFocus = traversalFunction(list, nextFocus, disableListWrap);
    } else {
      nextFocus.focus();
      return;
    }
  }
}

const useEnhancedEffect = typeof window === 'undefined' ? React.useEffect : React.useLayoutEffect;
/**
 * A permanently displayed menu following https://www.w3.org/TR/wai-aria-practices/#menubutton.
 * It's exposed to help customization of the [`Menu`](/api/menu/) component. If you
 * use it separately you need to move focus into the component manually. Once
 * the focus is placed inside the component it is fully keyboard accessible.
 */

const MenuList = /*#__PURE__*/React.forwardRef(function MenuList(props, ref) {
  const {
    // private
    // eslint-disable-next-line react/prop-types
    actions,
    autoFocus = false,
    autoFocusItem = false,
    children,
    className,
    disabledItemsFocusable = false,
    disableListWrap = false,
    onKeyDown,
    variant = 'selectedMenu'
  } = props,
        other = _objectWithoutPropertiesLoose(props, ["actions", "autoFocus", "autoFocusItem", "children", "className", "disabledItemsFocusable", "disableListWrap", "onKeyDown", "variant"]);

  const listRef = React.useRef(null);
  const textCriteriaRef = React.useRef({
    keys: [],
    repeating: true,
    previousKeyMatched: true,
    lastTime: null
  });
  useEnhancedEffect(() => {
    if (autoFocus) {
      listRef.current.focus();
    }
  }, [autoFocus]);
  React.useImperativeHandle(actions, () => ({
    adjustStyleForScrollbar: (containerElement, theme) => {
      // Let's ignore that piece of logic if users are already overriding the width
      // of the menu.
      const noExplicitWidth = !listRef.current.style.width;

      if (containerElement.clientHeight < listRef.current.clientHeight && noExplicitWidth) {
        const scrollbarSize = `${getScrollbarSize(true)}px`;
        listRef.current.style[theme.direction === 'rtl' ? 'paddingLeft' : 'paddingRight'] = scrollbarSize;
        listRef.current.style.width = `calc(100% + ${scrollbarSize})`;
      }

      return listRef.current;
    }
  }), []);

  const handleKeyDown = event => {
    const list = listRef.current;
    const key = event.key;
    /**
     * @type {Element} - will always be defined since we are in a keydown handler
     * attached to an element. A keydown event is either dispatched to the activeElement
     * or document.body or document.documentElement. Only the first case will
     * trigger this specific handler.
     */

    const currentFocus = ownerDocument(list).activeElement;

    if (key === 'ArrowDown') {
      // Prevent scroll of the page
      event.preventDefault();
      moveFocus(list, currentFocus, disableListWrap, disabledItemsFocusable, nextItem);
    } else if (key === 'ArrowUp') {
      event.preventDefault();
      moveFocus(list, currentFocus, disableListWrap, disabledItemsFocusable, previousItem);
    } else if (key === 'Home') {
      event.preventDefault();
      moveFocus(list, null, disableListWrap, disabledItemsFocusable, nextItem);
    } else if (key === 'End') {
      event.preventDefault();
      moveFocus(list, null, disableListWrap, disabledItemsFocusable, previousItem);
    } else if (key.length === 1) {
      const criteria = textCriteriaRef.current;
      const lowerKey = key.toLowerCase();
      const currTime = performance.now();

      if (criteria.keys.length > 0) {
        // Reset
        if (currTime - criteria.lastTime > 500) {
          criteria.keys = [];
          criteria.repeating = true;
          criteria.previousKeyMatched = true;
        } else if (criteria.repeating && lowerKey !== criteria.keys[0]) {
          criteria.repeating = false;
        }
      }

      criteria.lastTime = currTime;
      criteria.keys.push(lowerKey);
      const keepFocusOnCurrent = currentFocus && !criteria.repeating && textCriteriaMatches(currentFocus, criteria);

      if (criteria.previousKeyMatched && (keepFocusOnCurrent || moveFocus(list, currentFocus, false, disabledItemsFocusable, nextItem, criteria))) {
        event.preventDefault();
      } else {
        criteria.previousKeyMatched = false;
      }
    }

    if (onKeyDown) {
      onKeyDown(event);
    }
  };

  const handleOwnRef = React.useCallback(instance => {
    // #StrictMode ready
    listRef.current = ReactDOM.findDOMNode(instance);
  }, []);
  const handleRef = useForkRef(handleOwnRef, ref);
  /**
   * the index of the item should receive focus
   * in a `variant="selectedMenu"` it's the first `selected` item
   * otherwise it's the very first item.
   */

  let activeItemIndex = -1; // since we inject focus related props into children we have to do a lookahead
  // to check if there is a `selected` item. We're looking for the last `selected`
  // item and use the first valid item as a fallback

  React.Children.forEach(children, (child, index) => {
    if (! /*#__PURE__*/React.isValidElement(child)) {
      return;
    }

    if (process.env.NODE_ENV !== 'production') {
      if (isFragment(child)) {
        console.error(["Material-UI: The Menu component doesn't accept a Fragment as a child.", 'Consider providing an array instead.'].join('\n'));
      }
    }

    if (!child.props.disabled) {
      if (variant === 'selectedMenu' && child.props.selected) {
        activeItemIndex = index;
      } else if (activeItemIndex === -1) {
        activeItemIndex = index;
      }
    }
  });
  const items = React.Children.map(children, (child, index) => {
    if (index === activeItemIndex) {
      const newChildProps = {};

      if (autoFocusItem) {
        newChildProps.autoFocus = true;
      }

      if (child.props.tabIndex === undefined && variant === 'selectedMenu') {
        newChildProps.tabIndex = 0;
      }

      return /*#__PURE__*/React.cloneElement(child, newChildProps);
    }

    return child;
  });
  return /*#__PURE__*/React.createElement(List, _extends({
    role: "menu",
    ref: handleRef,
    className: className,
    onKeyDown: handleKeyDown,
    tabIndex: autoFocus ? 0 : -1
  }, other), items);
});
process.env.NODE_ENV !== "production" ? MenuList.propTypes = {
  // ----------------------------- Warning --------------------------------
  // | These PropTypes are generated from the TypeScript type definitions |
  // |     To update them edit the d.ts file and run "yarn proptypes"     |
  // ----------------------------------------------------------------------

  /**
   * If `true`, will focus the `[role="menu"]` container and move into tab order.
   */
  autoFocus: PropTypes.bool,

  /**
   * If `true`, will focus the first menuitem if `variant="menu"` or selected item
   * if `variant="selectedMenu"`.
   */
  autoFocusItem: PropTypes.bool,

  /**
   * MenuList contents, normally `MenuItem`s.
   */
  children: PropTypes.node,

  /**
   * @ignore
   */
  className: PropTypes.string,

  /**
   * If `true`, will allow focus on disabled items.
   */
  disabledItemsFocusable: PropTypes.bool,

  /**
   * If `true`, the menu items will not wrap focus.
   */
  disableListWrap: PropTypes.bool,

  /**
   * @ignore
   */
  onKeyDown: PropTypes.func,

  /**
   * The variant to use. Use `menu` to prevent selected items from impacting the initial focus
   * and the vertical alignment relative to the anchor element.
   */
  variant: PropTypes.oneOf(['menu', 'selectedMenu'])
} : void 0;
export default MenuList;