1/**
2 * Copyright (c) 2021 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
16
17export default class BasicDataSource implements IDataSource {
18  private listeners: DataChangeListener[] = [];
19
20  public totalCount(): number {
21    return 0;
22  }
23
24  public getData(index: number): any {
25    return undefined;
26  }
27
28  registerDataChangeListener(listener: DataChangeListener): void {
29    if (this.listeners.indexOf(listener) < 0) {
30      this.listeners.push(listener);
31    }
32  }
33
34  unregisterDataChangeListener(listener: DataChangeListener): void {
35    const position = this.listeners.indexOf(listener);
36    if (position >= 0) {
37      this.listeners.splice(position, 1);
38    }
39  }
40
41  notifyDataReload(): void {
42    this.listeners.forEach(listener => {
43      listener.onDataReloaded();
44    })
45  }
46
47  notifyDataAdd(index: number): void {
48    this.listeners.forEach(listener => {
49      listener.onDataAdded(index);
50    })
51  }
52
53  notifyDataChange(index: number): void {
54    this.listeners.forEach(listener => {
55      listener.onDataChanged(index);
56    })
57  }
58
59  notifyDataDelete(index: number): void {
60    this.listeners.forEach(listener => {
61      listener.onDataDeleted(index);
62    })
63  }
64
65  notifyDataMove(from: number, to: number): void {
66    this.listeners.forEach(listener => {
67      listener.onDataMoved(from, to);
68    })
69  }
70}