@primer/react/lib/deprecated/SelectMenu/hooks/useKeyboardNav.js

An implementation of GitHub's Primer Design System using React

'use strict';

var React = require('react');

// adapted from details-menu web component https://github.com/github/details-menu-element
function useKeyboardNav(details, open, setOpen) {
  const handleKeyDown = React.useCallback(event => {
    const closeDetails = () => {
      setOpen(false);
      const summary = details.current.querySelector('summary');
      if (summary) summary.focus();
    };
    const openDetails = () => {
      setOpen(true);
    };
    const focusItem = next => {
      const options = Array.from(details.current.querySelectorAll('[role^="menuitem"]:not([hidden]):not([disabled]):not([aria-disabled="true"])'));
      const selected = document.activeElement;
      const index = options.indexOf(selected);
      const found = next ? options[index + 1] : options[index - 1];
      const def = next ? options[0] : options[options.length - 1];
      return found || def;
    };
    const isMenuItem = el => {
      const role = el.getAttribute('role');
      return role === 'menuitem' || role === 'menuitemcheckbox' || role === 'menuitemradio';
    };
    if (!(event instanceof KeyboardEvent)) return;
    const isSummaryFocused = event.target instanceof Element && event.target.tagName === 'SUMMARY';
    switch (event.key) {
      case 'Escape':
        if (open) {
          closeDetails();
          event.preventDefault();
          event.stopPropagation();
        }
        break;
      case 'ArrowDown':
        {
          if (isSummaryFocused && !open) {
            openDetails();
          }
          const target = focusItem(true);
          if (target) target.focus();
          event.preventDefault();
        }
        break;
      case 'ArrowUp':
        {
          if (isSummaryFocused && !open) {
            openDetails();
          }
          const target = focusItem(false);
          if (target) target.focus();
          event.preventDefault();
        }
        break;
      case ' ':
      case 'Enter':
        {
          const selected = document.activeElement;
          if (selected && isMenuItem(selected) && selected.closest('details') === details) {
            event.preventDefault();
            event.stopPropagation();
            selected.click();
          }
        }
        break;
    }
  }, [details, open, setOpen]);
  React.useEffect(() => {
    const current = details.current;
    if (!current) return;
    current.addEventListener('keydown', handleKeyDown);
    return () => {
      current.removeEventListener('keydown', handleKeyDown);
    };
  }, [details, handleKeyDown]);
}

module.exports = useKeyboardNav;