From d9794916b0549330513fe530abf090fa48b8a776 Mon Sep 17 00:00:00 2001
From: Samuel Susla <samuelsusla@meta.com>
Date: Fri, 9 Feb 2024 04:06:52 -0800
Subject: [PATCH] remove animation from borderLayer to stop unwanted animations
 (#42922)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/42922

changelog: [fix][ios] prevent unwanted border animation

The problem: CALayer and its properties are animatable. If RN applies mutations inside an animation block, it will animate. In this particular example, it was animated because of a transition applied by the library and because we were not creating new views, but recycling views from previous screen.

This caused size of _borderLayer to change from value A to value B inside of animation block. To resolve this, call removeAllAnimations on borderLayer.

Reviewed By: cipolleschi

Differential Revision: D53566886

fbshipit-source-id: 98e0b01a9185046e1ee500665c1832060ecc8884
---
 .../View/RCTViewComponentView.mm              | 26 +++++++++----------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/packages/react-native/React/Fabric/Mounting/ComponentViews/View/RCTViewComponentView.mm b/packages/react-native/React/Fabric/Mounting/ComponentViews/View/RCTViewComponentView.mm
index d06b0aa8d1c2bf..a36c62bf0280f0 100644
--- a/packages/react-native/React/Fabric/Mounting/ComponentViews/View/RCTViewComponentView.mm
+++ b/packages/react-native/React/Fabric/Mounting/ComponentViews/View/RCTViewComponentView.mm
@@ -28,7 +28,7 @@
 
 @implementation RCTViewComponentView {
   UIColor *_backgroundColor;
-  CALayer *_borderLayer;
+  __weak CALayer *_borderLayer;
   BOOL _needsInvalidateLayer;
   BOOL _isJSResponder;
   BOOL _removeClippedSubviews;
@@ -397,9 +397,7 @@ - (void)updateLayoutMetrics:(const LayoutMetrics &)layoutMetrics
   _layoutMetrics = layoutMetrics;
   _needsInvalidateLayer = YES;
 
-  if (_borderLayer) {
-    _borderLayer.frame = self.layer.bounds;
-  }
+  _borderLayer.frame = self.layer.bounds;
 
   if (_contentView) {
     _contentView.frame = RCTCGRectFromRect(_layoutMetrics.getContentFrame());
@@ -601,10 +599,7 @@ - (void)invalidateLayer
 
   if (useCoreAnimationBorderRendering) {
     layer.mask = nil;
-    if (_borderLayer) {
-      [_borderLayer removeFromSuperlayer];
-      _borderLayer = nil;
-    }
+    [_borderLayer removeFromSuperlayer];
 
     layer.borderWidth = (CGFloat)borderMetrics.borderWidths.left;
     CGColorRef borderColor = RCTCreateCGColorRefFromSharedColor(borderMetrics.borderColors.left);
@@ -617,11 +612,12 @@ - (void)invalidateLayer
     layer.backgroundColor = _backgroundColor.CGColor;
   } else {
     if (!_borderLayer) {
-      _borderLayer = [CALayer new];
-      _borderLayer.zPosition = -1024.0f;
-      _borderLayer.frame = layer.bounds;
-      _borderLayer.magnificationFilter = kCAFilterNearest;
-      [layer addSublayer:_borderLayer];
+      CALayer *borderLayer = [CALayer new];
+      borderLayer.zPosition = -1024.0f;
+      borderLayer.frame = layer.bounds;
+      borderLayer.magnificationFilter = kCAFilterNearest;
+      [layer addSublayer:borderLayer];
+      _borderLayer = borderLayer;
     }
 
     layer.backgroundColor = nil;
@@ -662,6 +658,10 @@ - (void)invalidateLayer
       }
     }
 
+    // If mutations are applied inside of Animation block, it may cause _borderLayer to be animated.
+    // To stop that, imperatively remove all animations from _borderLayer.
+    [_borderLayer removeAllAnimations];
+
     // Stage 2.5. Custom Clipping Mask
     CAShapeLayer *maskLayer = nil;
     CGFloat cornerRadius = 0;