koel/resources/assets/js/utils/supports.js

import isMobile from 'ismobilejs'
import Vue from 'vue'
import { each } from 'lodash'

/**
 * Check if AudioContext is supported by the current browser.
 *
 * @return {Boolean}
 */
export function isAudioContextSupported () {
  // Apple device just doesn't love AudioContext that much.
  if (isMobile.apple.device) {
    return false
  }

  const AudioContext = (window.AudioContext ||
    window.webkitAudioContext ||
    window.mozAudioContext ||
    window.oAudioContext ||
    window.msAudioContext)

  if (!AudioContext) {
    return false
  }

  // Safari (MacOS & iOS alike) has webkitAudioContext, but is buggy.
  // @link http://caniuse.com/#search=audiocontext
  if (!(new AudioContext()).createMediaElementSource) {
    return false
  }

  return true
}

/**
 * Checks if HTML5 clipboard can be used.
 *
 * @return {Boolean}
 */
export function isClipboardSupported () {
  return 'execCommand' in document
}

/**
 * A simple event bus.
 *
 * @type {Object}
 */
const event = {
  bus: null,

  init () {
    if (!this.bus) {
      this.bus = new Vue()
    }

    return this
  },

  emit (name, ...args) {
    this.bus.$emit(name, ...args)
    return this
  },

  on () {
    if (arguments.length === 2) {
      this.bus.$on(arguments[0], arguments[1])
    } else {
      each(Object.keys(arguments[0]), key => {
        this.bus.$on(key, arguments[0][key])
      })
    }

    return this
  }
}

export { event }