tt-mp/es/helpers/debounce.js

一套组件化、可复用、易扩展的头条小程序 UI 组件库

export default function debounce(func, wait, immediate) {
  let timeout, args, context, timestamp, result

  function later() {
    const last = +new Date() - timestamp
    if (last < wait && last >= 0) {
      timeout = setTimeout(later, wait - last)
    } else {
      timeout = undefined
      if (!immediate) {
        result = func.apply(context, args)
        if (!timeout) {
          context = undefined
          args = undefined
        }
      }
    }
  }

  function debounced() {
    context = this
    args = arguments
    timestamp = +new Date()

    const callNow = immediate && !timeout
    if (!timeout) {
      timeout = setTimeout(later, wait)
    }

    if (callNow) {
      result = func.apply(context, args)
      context = undefined
      args = undefined
    }

    return result
  }

  function cancel() {
    if (timeout !== undefined) {
      clearTimeout(timeout)
      timeout = undefined
    }

    context = undefined
    args = undefined
  }

  debounced.cancel = cancel

  return debounced
}