Add children to separate _containerView, if needed

Summary:
A lot of the style decorators we have (filters, box shadows, borders, etc) use a separate sub-CALayer to accomplish what they want. This becomes an issue if we are clipping the content to the bounds and if these decorators extend beyond the bounds of the view as they are typically unaffected by this clipping. The main things here are `box-shadow` and `outline`. However, this implementation will let us fix some issues w.r.t content rendering under borders. See later diffs for that.

To fix this, if needed, we insert a `_containerView` to contain all of our subviews, and actually apply the clipping to. If this exists, our UIView will only have one subview, this one. But it may have multiple sublayers.

NOTE: This diff does not actually redirect the clipping. It just inserts the subview to test if this breaks anything in and of itself.

Changelog: [Internal]

Reviewed By: lenaic

Differential Revision: D61414649

packages/react-native/React/Fabric/Mounting/ComponentViews/View/RCTViewComponentView.mm

@@ -39,6 +39,8 @@ @implementation RCTViewComponentView {
   BOOL _removeClippedSubviews;
   NSMutableArray<UIView *> *_reactSubviews;
   NSSet<NSString *> *_Nullable _propKeysManagedByAnimated_DO_NOT_USE_THIS_IS_BROKEN;
+  UIView *_containerView;
+  BOOL _useCustomContainerView;
 }
 
 #ifdef RCT_DYNAMIC_FRAMEWORKS
@@ -54,6 +56,7 @@ - (instancetype)initWithFrame:(CGRect)frame
     _props = ViewShadowNode::defaultSharedProps();
     _reactSubviews = [NSMutableArray new];
     self.multipleTouchEnabled = YES;
+    _useCustomContainerView = NO;
   }
   return self;
 }
@@ -72,7 +75,7 @@ - (void)setContentView:(UIView *)contentView
   _contentView = contentView;
 
   if (_contentView) {
-    [self addSubview:_contentView];
+    [[self getContainerView] addSubview:_contentView];
     _contentView.frame = RCTCGRectFromRect(_layoutMetrics.getContentFrame());
   }
 }
@@ -129,7 +132,7 @@ - (void)mountChildComponentView:(UIView<RCTComponentViewProtocol> *)childCompone
   if (_removeClippedSubviews) {
     [_reactSubviews insertObject:childComponentView atIndex:index];
   } else {
-    [self insertSubview:childComponentView atIndex:index];
+    [[self getContainerView] insertSubview:childComponentView atIndex:index];
   }
 }
 
@@ -139,19 +142,20 @@ - (void)unmountChildComponentView:(UIView<RCTComponentViewProtocol> *)childCompo
     [_reactSubviews removeObjectAtIndex:index];
   } else {
     RCTAssert(
-        childComponentView.superview == self,
+        childComponentView.superview == [self getContainerView],
         @"Attempt to unmount a view which is mounted inside different view. (parent: %@, child: %@, index: %@)",
         self,
         childComponentView,
         @(index));
     RCTAssert(
-        (self.subviews.count > index) && [self.subviews objectAtIndex:index] == childComponentView,
+        ([self getContainerView].subviews.count > index) &&
+            [[self getContainerView].subviews objectAtIndex:index] == childComponentView,
         @"Attempt to unmount a view which has a different index. (parent: %@, child: %@, index: %@, actual index: %@, tag at index: %@)",
         self,
         childComponentView,
         @(index),
-        @([self.subviews indexOfObject:childComponentView]),
-        @([[self.subviews objectAtIndex:index] tag]));
+        @([[self getContainerView].subviews indexOfObject:childComponentView]),
+        @([[[self getContainerView].subviews objectAtIndex:index] tag]));
   }
 
   [childComponentView removeFromSuperview];
@@ -181,7 +185,7 @@ - (void)updateClippedSubviewsWithClipRect:(CGRect)clipRect relativeToView:(UIVie
   for (UIView *view in _reactSubviews) {
     if (CGRectIntersectsRect(clipRect, view.frame)) {
       // View is at least partially visible, so remount it if unmounted
-      [self addSubview:view];
+      [[self getContainerView] addSubview:view];
       // View is visible, update clipped subviews
       [view updateClippedSubviewsWithClipRect:clipRect relativeToView:self];
     } else if (view.superview) {
@@ -220,8 +224,8 @@ - (void)updateProps:(const Props::Shared &)props oldProps:(const Props::Shared &
 
   if (oldViewProps.removeClippedSubviews != newViewProps.removeClippedSubviews) {
     _removeClippedSubviews = newViewProps.removeClippedSubviews;
-    if (_removeClippedSubviews && self.subviews.count > 0) {
-      _reactSubviews = [NSMutableArray arrayWithArray:self.subviews];
+    if (_removeClippedSubviews && [self getContainerView].subviews.count > 0) {
+      _reactSubviews = [NSMutableArray arrayWithArray:[self getContainerView].subviews];
     }
   }
 
@@ -516,6 +520,10 @@ - (void)updateLayoutMetrics:(const LayoutMetrics &)layoutMetrics
     _contentView.frame = RCTCGRectFromRect(_layoutMetrics.getContentFrame());
   }
 
+  if (_containerView) {
+    _containerView.frame = CGRectMake(0, 0, self.layer.bounds.size.width, self.layer.bounds.size.height);
+  }
+
   if ((_props->transformOrigin.isSet() || _props->transform.operations.size() > 0) &&
       layoutMetrics.frame.size != oldLayoutMetrics.frame.size) {
     auto newTransform = _props->resolveTransform(layoutMetrics);
@@ -536,6 +544,7 @@ - (void)setIsJSResponder:(BOOL)isJSResponder
 - (void)finalizeUpdates:(RNComponentViewUpdateMask)updateMask
 {
   [super finalizeUpdates:updateMask];
+  _useCustomContainerView = [self styleWouldClipOverflowInk];
   if (!_needsInvalidateLayer) {
     return;
   }
@@ -561,6 +570,7 @@ - (void)prepareForRecycle
   _eventEmitter.reset();
   _isJSResponder = NO;
   _removeClippedSubviews = NO;
+  _useCustomContainerView = NO;
   _reactSubviews = [NSMutableArray new];
 }
 
@@ -675,6 +685,41 @@ static RCTBorderStyle RCTBorderStyleFromBorderStyle(BorderStyle borderStyle)
   }
 }
 
+- (BOOL)styleWouldClipOverflowInk
+{
+  const auto borderMetrics = _props->resolveBorderMetrics(_layoutMetrics);
+  BOOL nonZeroBorderWidth = !(borderMetrics.borderWidths.isUniform() && borderMetrics.borderWidths.left == 0);
+  return _props->getClipsContentToBounds() && (!_props->boxShadow.empty() || nonZeroBorderWidth);
+}
+
+// This UIView is the UIView that holds all subviews. It is sometimes not self
+// because we want to render "overflow ink" that extends beyond the bounds of
+// the view and is not affected by clipping.
+- (UIView *)getContainerView
+{
+  if (_useCustomContainerView) {
+    if (!_containerView) {
+      _containerView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];
+      for (UIView *subview in self.subviews) {
+        [_containerView addSubview:subview];
+      }
+      [self addSubview:_containerView];
+    }
+
+    return _containerView;
+  } else {
+    if (_containerView) {
+      for (UIView *subview in _containerView.subviews) {
+        [self addSubview:subview];
+      }
+      [_containerView removeFromSuperview];
+      _containerView = nil;
+    }
+
+    return self;
+  }
+}
+
 - (void)invalidateLayer
 {
   CALayer *layer = self.layer;
@@ -825,7 +870,7 @@ - (void)invalidateLayer
     layer.cornerRadius = cornerRadius;
     layer.mask = maskLayer;
 
-    for (UIView *subview in self.subviews) {
+    for (UIView *subview in [self getContainerView].subviews) {
       if ([subview isKindOfClass:[UIImageView class]]) {
         RCTCornerInsets cornerInsets = RCTGetCornerInsets(
             RCTCornerRadiiFromBorderRadii(borderMetrics.borderRadii),
@@ -993,7 +1038,7 @@ - (NSString *)accessibilityLabel
     return label;
   }
 
-  return RCTRecursiveAccessibilityLabel(self);
+  return RCTRecursiveAccessibilityLabel([self getContainerView]);
 }
 
 - (BOOL)isAccessibilityElement