vue + mui监听android物理返回键

mounted () {
    var quitTime = null
    window.mui.back = function () {
      if (!quitTime) {
        quitTime = new Date().getTime()
        window.mui.toast('再按一次退出应用')
        setTimeout(function () {
          quitTime = null
        }, 1800)
      } else {
        if ((new Date().getTime() - quitTime) < 1800) {
          quitTime = null
          window.plus.runtime.quit()
        }
      }
    }
  },

mounted () {
    window.mui.back = function () {
      window.history.go(-1)
    }
}

import Mui from 'vue-awesome-mui';

Vue.use(Mui);