weseek__growi/src/client/js/components/CustomNavigation.jsx

import React, { useEffect, useState } from 'react';
import PropTypes from 'prop-types';
import {
  Nav, NavItem, NavLink, TabContent, TabPane,
} from 'reactstrap';


const CustomNavigation = (props) => {
  const [activeTab, setActiveTab] = useState('');
  // [TODO: set default active tab by gw4079]
  const [sliderWidth, setSliderWidth] = useState(null);
  const [sliderMarginLeft, setSliderMarginLeft] = useState(null);

  function switchActiveTab(activeTab) {
    setActiveTab(activeTab);
  }

  // Might make this dynamic for px, %, pt, em
  function getPercentage(min, max) {
    return min / max * 100;
  }

  useEffect(() => {
    if (activeTab === '') {
      return;
    }

    const navBar = document.getElementById('grw-custom-navbar');
    const navTabs = document.querySelectorAll('ul.grw-custom-navbar > li.grw-custom-navtab');

    if (navBar == null || navTabs == null) {
      return;
    }

    let tempML = 0;

    const styles = [].map.call(navTabs, (el) => {
      const width = getPercentage(el.offsetWidth, navBar.offsetWidth);
      const marginLeft = tempML;
      tempML += width;
      return { width, marginLeft };
    });
    const { width, marginLeft } = styles[props.navTabMapping[activeTab].index];

    setSliderWidth(width);
    setSliderMarginLeft(marginLeft);

  }, [activeTab]);


  return (
    <React.Fragment>
      <Nav className="nav-title grw-custom-navbar" id="grw-custom-navbar">
        {Object.entries(props.navTabMapping).map(([key, value]) => {
          return (
            <NavItem key={key} type="button" className={`p-0 grw-custom-navtab ${activeTab === key && 'active'}`}>
              <NavLink onClick={() => { switchActiveTab(key) }}>
                {value.icon}
                {value.i18n}
              </NavLink>
            </NavItem>
          );
        })}
      </Nav>
      <hr className="my-0 grw-nav-slide-hr border-none" style={{ width: `${sliderWidth}%`, marginLeft: `${sliderMarginLeft}%` }} />
      <TabContent activeTab={activeTab} className="p-4">
        {Object.entries(props.navTabMapping).map(([key, value]) => {
          return (
            <TabPane key={key} tabId={key}>
              {value.tabContent}
            </TabPane>
          );
        })}
      </TabContent>
    </React.Fragment>
  );
};

CustomNavigation.propTypes = {
  navTabMapping: PropTypes.object,
};

export default CustomNavigation;