in components/js/virtualizedCollection.ts [88:101]
private _placeHolderGenerator: (index: number) => TData) {
this._windowSize = windowSize;
this._length = length;
let loadCompleteCallback = (start: number, end: number) => {
if (this.collectionChangedCallback) {
this.collectionChangedCallback(CollectionChange.ItemsReplaced, start, end - start);
}
};
this._bufferWindowBefore = new DataWindow(length, loadFn, _placeHolderGenerator, loadCompleteCallback);
this._window = new DataWindow(length, loadFn, _placeHolderGenerator, loadCompleteCallback);
this._bufferWindowAfter = new DataWindow(length, loadFn, _placeHolderGenerator, loadCompleteCallback);
}