1/*
2 * Copyright (c) 2021-2023 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 *     http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16let eventMap = {}
17
18export const emit = (event, ...argument) => {
19  if (Array.isArray(eventMap[event])) {
20    eventMap[event].forEach((fn: Function) => {
21      fn.apply(this, argument)
22    })
23  }
24}
25
26export const on = (event, callback) => {
27  if (!eventMap[event]) {
28    eventMap[event] = []
29  }
30  eventMap[event].push(callback)
31}
32
33export const off = (event, callback, flag = true) => {
34  if (flag) {
35    const index = eventMap[event].indexOf(item => item === callback)
36    if (index !== -1) {
37      eventMap[event].splice(index, 1)
38    }
39  } else {
40    eventMap[event] = []
41  }
42}