py-gtk-notes/inject.js

/**
 * {注入的js}
 * @author yutent<yutent.io@gmail.com>
 * @date 2023/07/21 17:38:11
 */

function defer() {
  let obj = {}
  obj.promise = new Promise((resolve, reject) => {
    obj.resolve = resolve
    obj.reject = reject
  })
  return obj
}

function rand(prefix = 'cb_') {
  return prefix + Math.random().toString().slice(2)
}

function handler(event, data = {}, once = true) {
  let _ = defer()
  let callback = rand()
  native[once ? '$once' : '$on'](callback, _.resolve)
  window.webkit.messageHandlers.app.postMessage({
    event,
    data,
    callback
  })
  return _.promise
}

class EventEmitter {
  //
  __events__ = Object.create(null)

  $on(name, fn) {
    if (this.__events__[name]) {
      this.__events__[name].push(fn)
    } else {
      this.__events__[name] = [fn]
    }
  }

  $once(name, fn) {
    fn.__once__ = true
    this.$on(name, fn)
  }

  $off(name, fn) {
    if (this.__events__[name]) {
      if (fn) {
        this.__events__[name] = this.__events__[name].filter(it => it !== fn)
      } else {
        this.__events__[name] = []
      }
    }
  }

  $emit(name, ...args) {
    if (this.__events__[name]) {
      for (let fn of this.__events__[name]) {
        try {
          fn.apply(this, args)
          if (fn.__once__) {
            this.$off(name, fn)
          }
        } catch (e) {
          console.error(e)
        }
      }
    }
  }

  $destroy() {
    this.__events__ = Object.create(null)
  }
}

window.native = new EventEmitter()

Object.assign(native, {
  fs: {
    read(filepath) {}
  },
  handler
})