element3/src/utils/menu/aria-submenu.js

A Component Library for Vue3

import Utils from '../aria-utils'

const SubMenu = function (parent, domNode) {
  this.domNode = domNode
  this.parent = parent
  this.subMenuItems = []
  this.subIndex = 0
  this.init()
}

SubMenu.prototype.init = function () {
  this.subMenuItems = this.domNode.querySelectorAll('li')
  this.addListeners()
}

SubMenu.prototype.gotoSubIndex = function (idx) {
  if (idx === this.subMenuItems.length) {
    idx = 0
  } else if (idx < 0) {
    idx = this.subMenuItems.length - 1
  }
  this.subMenuItems[idx].focus()
  this.subIndex = idx
}

SubMenu.prototype.addListeners = function () {
  const keys = Utils.keys
  const parentNode = this.parent.domNode
  Array.prototype.forEach.call(this.subMenuItems, (el) => {
    el.addEventListener('keydown', (event) => {
      let prevDef = false
      switch (event.keyCode) {
        case keys.down:
          this.gotoSubIndex(this.subIndex + 1)
          prevDef = true
          break
        case keys.up:
          this.gotoSubIndex(this.subIndex - 1)
          prevDef = true
          break
        case keys.tab:
          Utils.triggerEvent(parentNode, 'mouseleave')
          break
        case keys.enter:
        case keys.space:
          prevDef = true
          event.currentTarget.click()
          break
      }
      if (prevDef) {
        event.preventDefault()
        event.stopPropagation()
      }
      return false
    })
  })
}

export default SubMenu