hole_thu_frontend/src/Sidebar.js

import React, { PureComponent } from 'react';
import './Sidebar.css';

export class Sidebar extends PureComponent {
  constructor(props) {
    super(props);
    // this.sidebar_ref = React.createRef();
    this.do_close_bound = this.do_close.bind(this);
    this.do_back_bound = this.do_back.bind(this);
  }

  do_close() {
    this.props.show_sidebar(null, null, 'clear');
  }
  do_back() {
    this.props.show_sidebar(null, null, 'pop');
  }

  render() {
    // hide old contents to remember state
    let contents = this.props.stack.map(
      ({ 1: content }, i) =>
        content && (
          <div
            key={i}
            className={
              'sidebar-content ' +
              (i === this.props.stack.length - 1
                ? 'sidebar-content-show'
                : 'sidebar-content-hide')
            }
          >
            {content}
          </div>
        ),
    );
    let cur_title = this.props.stack[this.props.stack.length - 1][0];
    return (
      <div
        className={
          'sidebar-container ' +
          (cur_title !== null ? 'sidebar-on' : 'sidebar-off')
        }
      >
        <div
          className="sidebar-shadow"
          onClick={this.do_back_bound}
          onTouchEnd={(e) => {
            e.preventDefault();
            e.target.click();
          }}
        />
        <div className="sidebar">{contents}</div>
        <div className="sidebar-title">
          <a className="no-underline" onClick={this.do_close_bound}>
            &nbsp;
            <span className="icon icon-close" />
            &nbsp;
          </a>
          {this.props.stack.length > 2 && (
            <a className="no-underline" onClick={this.do_back_bound}>
              &nbsp;
              <span className="icon icon-back" />
              &nbsp;
            </a>
          )}
          {cur_title}
        </div>
      </div>
    );
  }
}