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
16export class BasicDataSource implements IDataSource {
17  private listeners: DataChangeListener[] = []
18
19  public totalCount(): number {
20    return 0
21  }
22
23  public getData(index: number): any {
24    return undefined
25  }
26
27  registerDataChangeListener(listener: DataChangeListener): void {
28    if (this.listeners.indexOf(listener) < 0) {
29      this.listeners.push(listener)
30    }
31  }
32
33  unregisterDataChangeListener(listener: DataChangeListener): void {
34    const pos = this.listeners.indexOf(listener)
35    if (pos >= 0) {
36      this.listeners.splice(pos, 1)
37    }
38  }
39
40  notifyDataReload(): void {
41    this.listeners.forEach(listener => {
42      listener.onDataReloaded()
43    })
44  }
45
46  notifyDataAdd(index: number): void {
47    this.listeners.forEach(listener => {
48      listener.onDataAdd(index)
49    })
50  }
51
52  notifyDataChange(index: number): void {
53    this.listeners.forEach(listener => {
54      listener.onDataChange(index)
55    })
56  }
57
58  notifyDataDelete(index: number): void {
59    this.listeners.forEach(listener => {
60      listener.onDataDelete(index)
61    })
62  }
63
64  notifyDataMove(from: number, to: number): void {
65    this.listeners.forEach(listener => {
66      listener.onDataMove(from, to)
67    })
68  }
69}