humus-old/client/ui/connection-status.js

// 3rd party.
import classnames from 'classnames';
import React, {useEffect, useState} from 'react';
// 2nd party.
import {compose} from '@avocado/core';
import contempo from 'contempo';

const decorate = compose(
  contempo(require('./connection-status.raw.scss').default),
);

const ConnectionStatusComponent = ({socket}) => {
  // Start true even if not really connected to prevent initial "interrupted"
  // state.
  const [isConnected, setIsConnected] = useState(true);
  const [dots, setDots] = useState(0);
  // Juggle connected state.
  useEffect(() => {
    const onConnect = () => {
      setIsConnected(true);
    };
    socket.on('connect', onConnect);
    const onDisconnect = () => {
      setIsConnected(false);
    };
    socket.on('disconnect', onDisconnect);
    return () => {
      socket.off('connect', onConnect);
      socket.off('disconnect', onDisconnect);
    };
  }, []);
  // Make the dots dance.
  useEffect(() => {
    if (isConnected) {
      return;
    }
    const handle = setTimeout(() => {
      setDots((dots + 1) % 39);
    }, 50);
    return () => {
      clearTimeout(handle);
    };
  }, [dots, isConnected]);
  const renderedDots = Array(dots + 1).fill('.').join('');
  return <div className={classnames(
    'connection-status',
    !isConnected ? 'interrupted' : '',
    'unselectable',
  )}>
    <div className="message">
      <p>:[ Connection interrupted ]:</p>
      <p className="dots">{renderedDots}</p>
    </div>
  </div>;
}

export default decorate(ConnectionStatusComponent);