1/**
2 * Copyright (c) 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 */
15import HiLog from '../utils/HiLog';
16
17const TAG = 'BasicDataSource'
18
19export default class BasicDataSource implements IDataSource {
20    private listeners: DataChangeListener[] = []
21
22    public totalCount(): number {
23        return 0
24    }
25
26    public getData(index: number): any {
27        return undefined
28    }
29
30    registerDataChangeListener(listener: DataChangeListener): void {
31        if (this.listeners.indexOf(listener) < 0) {
32            HiLog.i(TAG, 'add listener')
33            this.listeners.push(listener)
34        }
35    }
36
37    unregisterDataChangeListener(listener: DataChangeListener): void {
38        const pos = this.listeners.indexOf(listener);
39        if (pos >= 0) {
40            HiLog.i(TAG, 'remove listener')
41            this.listeners.splice(pos, 1)
42        }
43    }
44
45    notifyDataReload(): void {
46        this.listeners.forEach(listener => {
47            listener.onDataReloaded()
48        })
49    }
50
51    notifyDataAdd(index: number): void {
52        this.listeners.forEach(listener => {
53            listener.onDataAdd(index)
54        })
55    }
56
57    notifyDataChange(index: number): void {
58        this.listeners.forEach(listener => {
59            listener.onDataChange(index)
60        })
61    }
62
63    notifyDataDelete(index: number): void {
64        this.listeners.forEach(listener => {
65            listener.onDataDelete(index)
66        })
67    }
68
69    notifyDataMove(from: number, to: number): void {
70        this.listeners.forEach(listener => {
71            listener.onDataMove(from, to)
72        })
73    }
74}