1/* 2* Copyright (c) 2023 Hunan OpenValley Digital Industry Development 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 LinkedList from '@ohos.util.LinkedList'; 17import { BaseDataSource } from '@ohos/common/src/main/ets/components/BaseDataSource'; 18import { Information } from '../../model/Information'; 19 20export class LinkedListDataSource extends BaseDataSource { 21 private linkedList: LinkedList<Information> = new LinkedList(); 22 23 public totalCount(): number { 24 return this.linkedList.length; 25 } 26 27 public getData(index: number): Information { 28 return this.linkedList[index]; 29 } 30 31 public addData(item: Information): void { 32 this.linkedList.add(item); 33 this.notifyDataAdd(this.linkedList.length - 1); 34 this.notifyDataReload(); 35 } 36 37 public deleteFirst(): void { 38 this.linkedList.removeFirst(); 39 this.notifyDataDelete(0); 40 this.notifyDataReload(); 41 } 42 43 public deleteLast(): void { 44 this.linkedList.removeLast(); 45 this.notifyDataDelete(this.linkedList.length - 1); 46 this.notifyDataReload(); 47 } 48 49 public deleteData(index: number): void { 50 this.linkedList.removeByIndex(index); 51 this.notifyDataDelete(index); 52 this.notifyDataReload(); 53 } 54}