do not send onScroll event when ScrollView is reused (#43676)

sammy-SC · pull[bot] · commit b1f141839987 · 2024-08-20T12:25:36.000Z
Summary: Pull Request resolved: #43676 changelog: [internal] calling super invalidates eventEmitter. EventEmitter should be invalidated before reseting contentOffset on `_scrollView. Otherwise, UIScrollView::setContentOffset is called and it calls delegate method: `scrollViewDidScroll`. Reviewed By: javache Differential Revision: D55375060 fbshipit-source-id: f697805eb1ca05d15cf498ff9e5e06e90eb7ac56
diff --git a/packages/react-native/React/Fabric/Mounting/ComponentViews/ScrollView/RCTScrollViewComponentView.mm b/packages/react-native/React/Fabric/Mounting/ComponentViews/ScrollView/RCTScrollViewComponentView.mm
@@ -418,6 +418,7 @@ - (void)_updateStateWithContentOffset
 
 - (void)prepareForRecycle
 {
+  [super prepareForRecycle];
   const auto &props = static_cast<const ScrollViewProps &>(*_props);
   _scrollView.contentOffset = RCTCGPointFromPoint(props.contentOffset);
   // We set the default behavior to "never" so that iOS
@@ -433,7 +434,6 @@ - (void)prepareForRecycle
   _contentView = nil;
   _prevFirstVisibleFrame = CGRectZero;
   _firstVisibleView = nil;
-  [super prepareForRecycle];
 }
 
 #pragma mark - UIScrollViewDelegate

Original file line number	Diff line number	Diff line change
`@@ -418,6 +418,7 @@ - (void)_updateStateWithContentOffset`
`418`	`418`
`419`	`419`	`- (void)prepareForRecycle`
`420`	`420`	`{`
	`421`	`+ [super prepareForRecycle];`
`421`	`422`	`const auto &props = static_cast<const ScrollViewProps &>(*_props);`
`422`	`423`	`_scrollView.contentOffset = RCTCGPointFromPoint(props.contentOffset);`
`423`	`424`	`// We set the default behavior to "never" so that iOS`
`@@ -433,7 +434,6 @@ - (void)prepareForRecycle`
`433`	`434`	`_contentView = nil;`
`434`	`435`	`_prevFirstVisibleFrame = CGRectZero;`
`435`	`436`	`_firstVisibleView = nil;`
`436`		`- [super prepareForRecycle];`
`437`	`437`	`}`
`438`	`438`
`439`	`439`	`#pragma mark - UIScrollViewDelegate`