w-ui/src/transitions/collapse-transition.js

A Vue.js 2.0 UI Toolkit for mobile

import { addClass, removeClass } from 'element-ui/src/utils/dom'

class Transition {
  beforeEnter (el) {
    addClass(el, 'collapse-transition')
    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) {
    // for safari: remove class then reset height is necessary
    removeClass(el, 'collapse-transition')
    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) {
      // for safari: add class after set height, or it will jump to zero height suddenly, weired
      addClass(el, 'collapse-transition')
      el.style.height = 0
      el.style.paddingTop = 0
      el.style.paddingBottom = 0
    }
  }

  afterLeave (el) {
    removeClass(el, 'collapse-transition')
    el.style.height = ''
    el.style.overflow = el.dataset.oldOverflow
    el.style.paddingTop = el.dataset.oldPaddingTop
    el.style.paddingBottom = el.dataset.oldPaddingBottom
  }
}

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

    return h('transition', data, children)
  }
}