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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 */
15
16
17@Entry
18@Component
19struct MyComponent {
20  @State arr: number[] = [10, 20, 30]
21
22  build() {
23    Column({ space: 5 }) {
24      Button('Reverse Array')
25        .onClick(() => {
26          this.arr.reverse()
27        })
28
29      ForEach(this.arr, (item: number) => {
30        Text(`item value: ${item}`).fontSize(18)
31        Divider().strokeWidth(2)
32      }, (item: number) => item.toString())
33    }
34  }
35}
36
37
38interface DataChangeListener {
39  onDataReloaded(): void;
40  onDataAdd(index: number): void;
41  onDataMove(from: number, to: number): void;
42  onDataDelete(index: number): void;
43  onDataChange(index: number): void;
44}
45
46
47class BasicDataSource02 implements IDataSource {
48  private listeners: DataChangeListener[] = []
49  public getData(index: number): any {
50    return undefined;
51  }
52  public totalCount(): number {
53    return 0;
54  }
55
56  registerDataChangeListener(listener: DataChangeListener): void {
57    if (this.listeners.indexOf(listener) < 0) {
58      this.listeners.push(listener)
59    }
60  }
61
62  unregisterDataChangeListener(listener: DataChangeListener): void {
63    const pos = this.listeners.indexOf(listener);
64    if (pos >= 0) {
65      this.listeners.splice(pos, 1)
66    }
67  }
68
69  informDataReload(): void {
70    this.listeners.forEach(listener => {
71      listener.onDataReloaded()
72    })
73  }
74
75  informDataAdd(index: number): void {
76    this.listeners.forEach(listener => {
77      listener.onDataAdd(index)
78    })
79  }
80
81  informDataChange(index: number): void {
82    this.listeners.forEach(listener => {
83      listener.onDataChange(index)
84    })
85  }
86
87  informDataDelete(index: number): void {
88    this.listeners.forEach(listener => {
89      listener.onDataDelete(index)
90    })
91  }
92
93  informDataMove02(from: number, to: number): void {
94    this.listeners.forEach(listener => {
95      listener.onDataMove(from, to)
96    })
97  }
98}
99
100class MyDataSource02 extends BasicDataSource02 {
101  private dataArray: string[] = ['/path/image0.png', '/path/image1.png', '/path/image2.png', '/path/image3.png']
102
103  public totalCount02(): number {
104    return this.dataArray.length
105  }
106
107  public getData(index: number): any {
108    return this.dataArray[index]
109  }
110
111  public addData(index: number, data: string): void {
112    this.dataArray.splice(index, 0, data)
113    this.informDataAdd(index)
114  }
115
116  public pushData(data: string): void {
117    this.dataArray.push(data)
118    this.informDataAdd(this.dataArray.length - 1)
119  }
120}
121
122@Entry
123@Component
124struct MyComponent02 {
125  private data: MyDataSource02 = new MyDataSource02()
126
127  build() {
128    List({ space: 3 }) {
129      LazyForEach(this.data, (item: string) => {
130        ListItem() {
131          Row() {
132            Image(item).width(50).height(50)
133          }.margin({ left: 10, right: 10 })
134        }
135        .onClick(() => {
136          this.data.pushData('/path/image' + this.data.totalCount02() + '.png')
137        })
138      }, item => item)
139    }
140  }
141}