vcc-ui/dist/esm/components/nav/index.js

A React library for building user interfaces at Volvo Cars

import { createKeyboardNavigation } from '@volvo-cars/react-aria';
import PropTypes from 'prop-types';
import React, { forwardRef, useEffect, useState } from 'react';
import { useTheme } from '../../styling/use-theme';
import { Block } from '../block';
export const {
  useKeyboardNavigation,
  KeyboardNavigationProvider
} = createKeyboardNavigation();
const hideOnScrollOffsetTop = 80;
const navStyle = _ref => {
  let {
    theme,
    sticky,
    hideOnScroll,
    isVisible
  } = _ref;
  return {
    position: 'relative',
    zIndex: 10,
    width: '100%',
    background: theme.color.background.primary,
    boxSizing: 'border-box',
    ':before': {
      content: "''",
      display: 'block',
      background: theme.color.ornament.divider,
      height: 1,
      outline: 'none',
      position: 'absolute',
      left: 0,
      right: 0,
      zIndex: -1,
      bottom: 0
    },
    extend: [{
      condition: sticky,
      style: {
        position: 'fixed',
        top: 0,
        left: 0
      }
    }, {
      condition: hideOnScroll,
      style: {
        transition: 'transform 200ms ease-out'
      }
    }, {
      condition: !isVisible,
      style: {
        transform: 'translateY(-100%)'
      }
    }]
  };
};

// using an external variable for performance reasons
let previousScrollY = 0;
/**
 * @deprecated Use `<nav>` element instead.
 */
export const Nav = /*#__PURE__*/forwardRef((_ref2, ref) => {
  let {
    hideOnScroll = false,
    sticky = false,
    children
  } = _ref2;
  const [isVisible, setVisible] = useState(true);
  const theme = useTheme();
  useEffect(() => {
    const toggleVisibility = () => {
      if (window.scrollY > previousScrollY) {
        if (isVisible && window.scrollY > hideOnScrollOffsetTop) {
          setVisible(false);
        }
      } else {
        if (!isVisible) {
          setVisible(true);
        }
      }
      previousScrollY = window.scrollY;
    };
    if (hideOnScroll) {
      window.addEventListener('scroll', toggleVisibility);
    }
    return () => {
      window.removeEventListener('scroll', toggleVisibility);
    };
  }, [hideOnScroll, isVisible]);
  const styleProps = {
    sticky,
    hideOnScroll,
    isVisible,
    theme
  };
  return /*#__PURE__*/React.createElement(Block, {
    as: "nav",
    ref: ref,
    extend: navStyle(styleProps)
  }, /*#__PURE__*/React.createElement(KeyboardNavigationProvider, null, children));
});
Nav.displayName = 'Nav';
Nav.propTypes = {
  /** Automatically hide the sticky navigation if the user starts scrolling */
  hideOnScroll: PropTypes.bool,
  /** Make the navigation stick to the top of the viewport */
  sticky: PropTypes.bool,
  /** A JSX node */
  // @ts-ignore
  children: PropTypes.node
};