xref: /applications/standard/mms/entry/src/main/ets/model/BaseDataSource.ets

/**
 * Copyright (c) 2022 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import HiLog from '../utils/HiLog';

const TAG = 'BasicDataSource'

export default class BasicDataSource implements IDataSource {
    private listeners: DataChangeListener[] = []

    public totalCount(): number {
        return 0
    }

    public getData(index: number): any {
        return undefined
    }

    registerDataChangeListener(listener: DataChangeListener): void {
        if (this.listeners.indexOf(listener) < 0) {
            HiLog.i(TAG, 'add listener')
            this.listeners.push(listener)
        }
    }

    unregisterDataChangeListener(listener: DataChangeListener): void {
        const pos = this.listeners.indexOf(listener);
        if (pos >= 0) {
            HiLog.i(TAG, 'remove listener')
            this.listeners.splice(pos, 1)
        }
    }

    notifyDataReload(): void {
        this.listeners.forEach(listener => {
            listener.onDataReloaded()
        })
    }

    notifyDataAdd(index: number): void {
        this.listeners.forEach(listener => {
            listener.onDataAdd(index)
        })
    }

    notifyDataChange(index: number): void {
        this.listeners.forEach(listener => {
            listener.onDataChange(index)
        })
    }

    notifyDataDelete(index: number): void {
        this.listeners.forEach(listener => {
            listener.onDataDelete(index)
        })
    }

    notifyDataMove(from: number, to: number): void {
        this.listeners.forEach(listener => {
            listener.onDataMove(from, to)
        })
    }
}