docsify/src/core/render/progressbar.js

import * as dom from '../util/dom'

let barEl
let timeId

/**
 * Init progress component
 */
function init() {
  const div = dom.create('div')

  div.classList.add('progress')
  dom.appendTo(dom.body, div)
  barEl = div
}

/**
 * Render progress bar
 */
export default function ({loaded, total, step}) {
  let num

  !barEl && init()

  if (step) {
    num = parseInt(barEl.style.width || 0, 10) + step
    num = num > 80 ? 80 : num
  } else {
    num = Math.floor(loaded / total * 100)
  }

  barEl.style.opacity = 1
  barEl.style.width = num >= 95 ? '100%' : num + '%'

  if (num >= 95) {
    clearTimeout(timeId)
    timeId = setTimeout(_ => {
      barEl.style.opacity = 0
      barEl.style.width = '0%'
    }, 200)
  }
}