1/**
2 * Copyright (c) 2021-2022 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
16import { Log } from '../utils/Log';
17import { CommonConstants } from '../constants/CommonConstants';
18
19const TAG = 'LocalEventManager';
20
21/**
22 * Local event management class
23 * main duty:
24 * 1.Registration and deregistration of event listeners
25 * 2.distribution of events
26 */
27class LocalEventManager {
28  private mEventListenerMap: Object = {};
29
30  private mEventMsgCache: Object = {};
31
32  /**
33   * Get the local event management class object
34   *
35   * @return Single instance of local event management class object
36   */
37  static getInstance(): LocalEventManager {
38    if (globalThis.localEventManager == null) {
39      globalThis.localEventManager = new LocalEventManager();
40    }
41    return globalThis.localEventManager;
42  }
43
44  /**
45   * register listener
46   *
47   * @param listener
48   * @param events
49   */
50  registerEventListener(listener, events: string[]): void {
51    Log.showInfo(TAG, `registerEventListener events: ${JSON.stringify(events)}`);
52    if (listener != null && events != null) {
53      for (let index = 0; index < events.length; index++) {
54        const event: string = events[index];
55        if (this.mEventListenerMap[event] == undefined) {
56          this.mEventListenerMap[event] = new Array<any>();
57        }
58        if (this.mEventListenerMap[event].indexOf(listener) === CommonConstants.INVALID_VALUE) {
59          this.mEventListenerMap[event].push(listener);
60        }
61      }
62    }
63  }
64
65  /**
66   * unregister listener
67   *
68   * @param listener
69   */
70  unregisterEventListener(listener): void {
71    Log.showInfo(TAG, 'unregisterEventListener event listener');
72    for(const key in this.mEventListenerMap) {
73      const listenerList: any[] = this.mEventListenerMap[key];
74      const index: number = listenerList.indexOf(listener);
75      if (index != CommonConstants.INVALID_VALUE) {
76        this.mEventListenerMap[key].splice(index, 1);
77      }
78    }
79  }
80
81  /**
82   * Send local broadcasts synchronously
83   *
84   * @param event
85   * @param params
86   */
87  sendLocalEvent(event, params?): void {
88    Log.showInfo(TAG, `sendLocalEvent event: ${JSON.stringify(event)}`);
89    let listenerList = this.mEventListenerMap[event];
90    if (listenerList != undefined) {
91      Log.showDebug(TAG, `sendLocalEvent listenerList length: ${listenerList.length}`);
92      for (let listener of listenerList) {
93        listener.onReceiveEvent(event, params);
94      }
95    } else {
96      Log.showInfo(TAG, 'sendLocalEvent, send local event with no receiver');
97    }
98  }
99
100  /**
101   * Send local broadcast asynchronously
102   *
103   * @param event
104   * @param params
105   */
106  async sendLocalEventAsync(event, params?): Promise<void> {
107    this.sendLocalEvent(event, params);
108  }
109
110  /**
111   * Send sticky local broadcast (async only)
112   *
113   * @param event
114   * @param params
115   */
116  async sendLocalEventSticky(event, params): Promise<void> {
117    Log.showDebug(TAG, `sendLocalEventSticky, send local event sticky, params: ${JSON.stringify(params)}`);
118    this.sendLocalEvent(event, params);
119    this.mEventMsgCache[event] = params;
120  }
121}
122
123export const localEventManager = LocalEventManager.getInstance();
124