zoro-cli/lib/plugins/config-web/template/src/util/dom/touch.js

https://github.com/vuejs/vue-cli

import { packAddEventListenerOptionsNoPassive } from './passive'
import { getScrollTop } from './scroll'
import { on, off, stopPropagation } from './event'

export function getTouchEventTouch(event) {
  if (!event) return {}
  const { changedTouches: touches } = event
  if (!touches || !touches.length) return {}
  return touches[0] || {}
}

export function getTouchEventPageBox(event) {
  const touch = getTouchEventTouch(event)
  const { screenX, screenY, pageX, pageY, clientX, clientY } = touch
  return {
    screenX: screenX || 0,
    screenY: screenY || 0,
    pageX: pageX || 0,
    pageY: pageY || 0,
    clientX: clientX || 0,
    clientY: clientY || 0,
  }
}

export function getTouchEventPageY(event) {
  const box = getTouchEventPageBox(event)
  return box.pageY
}

const disableBounceDefaultTarget = document.body

function handleBounceTouchStart(element, event) {
  const isDefault = element === disableBounceDefaultTarget
  const scrollTop = isDefault ? getScrollTop() : element.scrollTop
  const scrollHeight = isDefault
    ? document.documentElement.scrollHeight
    : element.scrollHeight
  const clientHeight = isDefault
    ? document.documentElement.clientHeight
    : element.clientHeight
  element.allowDown = scrollTop < scrollHeight - clientHeight
  element.allowUp = scrollTop > 0
  element.slideBeginY = getTouchEventPageY(event)
}

function handleBounceTouchMove(element, event) {
  const pageY = getTouchEventPageY(event)
  const up = pageY > element.slideBeginY
  const down = !up
  if ((up && element.allowUp) || (down && element.allowDown)) {
    event.stopPropagation()
  } else {
    event.preventDefault()
  }
}

// options: passive option defaults to true for touchstart and touchmove events
export function disableBounce(element = disableBounceDefaultTarget) {
  const options = packAddEventListenerOptionsNoPassive()

  element.handleBounceTouchStart = handleBounceTouchStart.bind(null, element)
  on(element, 'touchstart', element.handleBounceTouchStart, options)

  element.handleBounceTouchMove = handleBounceTouchMove.bind(null, element)
  on(element, 'touchmove', element.handleBounceTouchMove, options)
}

export function enableBounce(element = disableBounceDefaultTarget) {
  off(element, 'touchstart', element.handleBounceTouchStart)
  off(element, 'touchmove', element.handleBounceTouchMove)
}

export function disableTouchPropagation(element) {
  const options = packAddEventListenerOptionsNoPassive()
  on(element, 'touchstart', stopPropagation, options)
  on(element, 'touchmove', stopPropagation, options)
  on(element, 'touchend', stopPropagation, options)
  disableBounce(element)
}

export function enableTouchPropagation(element) {
  off(element, 'touchstart', stopPropagation)
  off(element, 'touchmove', stopPropagation)
  off(element, 'touchend', stopPropagation)
  enableBounce(element)
}