添加lazyForEach的处理类

commons/basic/src/main/ets/utils/LazyForeachDeal.ets

@@ -0,0 +1,113 @@
+// BasicDataSource实现了IDataSource接口，用于管理listener监听，以及通知LazyForEach数据更新
+class BasicDataSource implements IDataSource {
+  private listeners: DataChangeListener[] = [];
+  private originDataArray: object[] = [];
+
+  public totalCount(): number {
+    return 0;
+  }
+
+  public getData(index: number): object {
+    return this.originDataArray[index];
+  }
+
+  // 该方法为框架侧调用，为LazyForEach组件向其数据源处添加listener监听
+  registerDataChangeListener(listener: DataChangeListener): void {
+    if (this.listeners.indexOf(listener) < 0) {
+      console.info('add listener');
+      this.listeners.push(listener);
+    }
+  }
+
+  // 该方法为框架侧调用，为对应的LazyForEach组件在数据源处去除listener监听
+  unregisterDataChangeListener(listener: DataChangeListener): void {
+    const pos = this.listeners.indexOf(listener);
+    if (pos >= 0) {
+      console.info('remove listener');
+      this.listeners.splice(pos, 1);
+    }
+  }
+
+  // 通知LazyForEach组件需要重载所有子组件
+  notifyDataReload(): void {
+    this.listeners.forEach(listener => {
+      listener.onDataReloaded();
+    })
+  }
+
+  // 通知LazyForEach组件需要在index对应索引处添加子组件
+  notifyDataAdd(index: number): void {
+    this.listeners.forEach(listener => {
+      listener.onDataAdd(index);
+      // 写法2：listener.onDatasetChange([{type: DataOperationType.ADD, index: index}]);
+    })
+  }
+
+  // 通知LazyForEach组件在index对应索引处数据有变化，需要重建该子组件
+  notifyDataChange(index: number): void {
+    this.listeners.forEach(listener => {
+      listener.onDataChange(index);
+      // 写法2：listener.onDatasetChange([{type: DataOperationType.CHANGE, index: index}]);
+    })
+  }
+
+  // 通知LazyForEach组件需要在index对应索引处删除该子组件
+  notifyDataDelete(index: number): void {
+    this.listeners.forEach(listener => {
+      listener.onDataDelete(index);
+      // 写法2：listener.onDatasetChange([{type: DataOperationType.DELETE, index: index}]);
+    })
+  }
+
+  // 通知LazyForEach组件将from索引和to索引处的子组件进行交换
+  notifyDataMove(from: number, to: number): void {
+    this.listeners.forEach(listener => {
+      listener.onDataMove(from, to);
+      // 写法2：listener.onDatasetChange(
+      // [{type: DataOperationType.EXCHANGE, index: {start: from, end: to}}]);
+    })
+  }
+
+  notifyDatasetChange(operations: DataOperation[]): void {
+    this.listeners.forEach(listener => {
+      listener.onDatasetChange(operations);
+    })
+  }
+}
+
+export class LazyForeachDeal extends BasicDataSource {
+  private dataArray: object[] = [];
+
+  public totalCount(): number {
+    return this.dataArray.length;
+  }
+
+  public getData(index: number): object {
+    return this.dataArray[index];
+  }
+
+  public pushData(data: object): void {
+    this.dataArray.push(data);
+    this.notifyDataAdd(this.dataArray.length - 1);
+  }
+
+
+  public concatList(data: object[]): void {
+    this.dataArray.push(...data)
+    this.notifyDatasetChange([{
+      type: DataOperationType.ADD,
+      index: this.dataArray.length - 1,
+      count: data.length
+    }])
+  }
+
+  public deleteData(index: number): void {
+    this.dataArray.splice(index, 1);
+    this.notifyDataDelete(index);
+  }
+
+  public reloadData(dataArray: object[]): void {
+    this.dataArray = dataArray
+    this.notifyDataReload();
+  }
+}