adding comments to scroll to top/bottom optimization

facebook · Jul 6, 2022 · 06fb1dd · 06fb1dd
1 parent 5b2cb47
commit 06fb1dd
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/Libraries/Lists/VirtualizedList.js b/Libraries/Lists/VirtualizedList.js
@@ -944,6 +944,7 @@ class VirtualizedList extends React.PureComponent<Props, State> {
         ? -1
         : initialNumToRenderOrDefault(this.props.initialNumToRender) - 1;
       const {first, last} = this.state;
+      // scroll to top optimization. The first page is always rendered.
       if (!this.props.inverted) {
         this._pushCells(
           cells,
@@ -1006,6 +1007,7 @@ class VirtualizedList extends React.PureComponent<Props, State> {
         firstAfterInitial,
         last,
       );
+      // scroll to bottom optimization. The last page is always rendered in an inverted flatlist.
       if (this.props.inverted) {
         this._pushCells(
           cells,