vue-yizun-ui/src/package/Menu/slider.js

易尊前端组件库

class Transition {
  beforeEnter (el) {
    if (!el.dataset) {
      el.dataset = {}
    }
    el.dataset.oldPaddingTop = el.style.paddingTop
    el.dataset.oldPaddingBottom = el.style.paddingBottom

    el.style.height = '0'
    el.style.paddingTop = 0
    el.style.paddingBottom = 0
  }

  enter (el) {
    el.dataset.oldOverflow = el.style.overflow
    if (el.scrollHeight !== 0) {
      el.style.height = el.scrollHeight + 'px'
      el.style.paddingTop = el.dataset.oldPaddingTop
      el.style.paddingBottom = el.dataset.oldPaddingBottom
    } else {
      el.style.height = ''
      el.style.paddingTop = el.dataset.oldPaddingTop
      el.style.paddingBottom = el.dataset.oldPaddingBottom
    }

    el.style.overflow = 'hidden'
  }

  afterEnter (el) {
    el.style.height = ''
    el.style.overflow = el.dataset.oldOverflow
  }

  beforeLeave (el) {
    if (!el.dataset) {
      el.dataset = {}
    }
    el.dataset.oldPaddingTop = el.style.paddingTop
    el.dataset.oldPaddingBottom = el.style.paddingBottom
    el.dataset.oldOverflow = el.style.overflow

    el.style.height = el.scrollHeight + 'px'
    el.style.overflow = 'hidden'
  }

  leave (el) {
    if (el.scrollHeight !== 0) {
      el.style.height = 0
      el.style.paddingTop = 0
      el.style.paddingBottom = 0
    }
  }

  afterLeave (el) {
    el.style.height = ''
    el.style.overflow = el.dataset.oldOverflow
    el.style.paddingTop = el.dataset.oldPaddingTop
    el.style.paddingBottom = el.dataset.oldPaddingBottom
  }
}

export default {
  functional: true,
  render (h, {children}) {
    const data = {
      on: new Transition()
    }
    return h('transition', data, children)
  }
}