hole_thu_frontend/src/Sidebar.js

import React, { Component, 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);
  }

  componentDidUpdate(nextProps) {
    if (this.props.stack !== nextProps.stack) {
      //console.log('sidebar top');
      if (this.sidebar_ref.current) this.sidebar_ref.current.scrollTop = 0;
    }
  }

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

  render() {
    let [cur_title, cur_content] = this.props.stack[
      this.props.stack.length - 1
    ];
    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 ref={this.sidebar_ref} className="sidebar">
          {cur_content}
        </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>
    );
  }
}