chore(iOS, Stack): remove legacy architecture related code (#3788)

## Description

This PR removes legacy architecture related code from Stack related
files.


NOTE: Public headers in the RNScreens module are processed by the Clang
dependency
scanner without any preprocessor defines. Previously,
`RCT_NEW_ARCH_ENABLED`
guards shielded the scanner from C++ headers by falling through
to the Paper (ObjC-only) branches.

With Paper code removed, the scanner now hits C++ headers
unconditionally
and fails on <atomic> and other C++ stdlib headers.

This PR guards C++ content (imports, namespaces, LayoutMetrics, method
signatures)
  with `#if defined(__cplusplus)`.

Closes
https://github.com/issues/assigned?issue=software-mansion%7Creact-native-screens-labs%7C1035

## Changes
                                                            
- remove `#ifdef RCT_NEW_ARCH_ENABLED` guards (replace them with `#if
defined(__cplusplus)` when needed)
  - remove methods not used on Fabric architecture
- provides minimal `UIView` fallbacks for the scanner
- remove Paper-only imports


## After - visual documentation



https://github.com/user-attachments/assets/c4471a88-f081-40e7-a6c2-27d940cdd599



## Test plan

Check if app builds and tests for Stack work correctly.

## Checklist

- [ ] Included code example that can be used to test this change.
- [ ] Updated / created local changelog entries in relevant test files.
- [ ] For visual changes, included screenshots / GIFs / recordings
documenting the change.
- [ ] For API changes, updated relevant public types.
- [x] Ensured that CI passes

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: sgaczol

ios/RCTConvert+RNScreens.h

@@ -1,15 +1,5 @@
 #pragma once
 
-#if !RCT_NEW_ARCH_ENABLED
-
-#import <React/RCTConvert.h>
-
-NS_ASSUME_NONNULL_BEGIN
-
-@interface RCTConvert (RNScreens)
-
-@end
-
-NS_ASSUME_NONNULL_END
-
-#endif // !RCT_NEW_ARCH_ENABLED
+// This file is intentionally empty — all content was Paper-only and has been
+// removed as part of the Paper architecture removal. The file will be deleted
+// at the very end of the removal.

ios/RCTConvert+RNScreens.mm

@@ -1,69 +1,4 @@
 #import "RCTConvert+RNScreens.h"
 
-#if !RCT_NEW_ARCH_ENABLED
-
-#import "RNSEnums.h"
-
-@implementation RCTConvert (RNScreens)
-
-+ (NSMutableDictionary *)blurEffectsForIOSVersion
-{
-  NSMutableDictionary *blurEffects = [NSMutableDictionary new];
-  [blurEffects addEntriesFromDictionary:@{
-    @"none" : @(RNSBlurEffectStyleNone),
-    @"systemDefault" : @(RNSBlurEffectStyleSystemDefault),
-    @"extraLight" : @(RNSBlurEffectStyleExtraLight),
-    @"light" : @(RNSBlurEffectStyleLight),
-    @"dark" : @(RNSBlurEffectStyleDark),
-    @"regular" : @(RNSBlurEffectStyleRegular),
-    @"prominent" : @(RNSBlurEffectStyleProminent),
-  }];
-
-#if !TARGET_OS_TV
-  [blurEffects addEntriesFromDictionary:@{
-    @"systemUltraThinMaterial" : @(RNSBlurEffectStyleSystemUltraThinMaterial),
-    @"systemThinMaterial" : @(RNSBlurEffectStyleSystemThinMaterial),
-    @"systemMaterial" : @(RNSBlurEffectStyleSystemMaterial),
-    @"systemThickMaterial" : @(RNSBlurEffectStyleSystemThickMaterial),
-    @"systemChromeMaterial" : @(RNSBlurEffectStyleSystemChromeMaterial),
-    @"systemUltraThinMaterialLight" : @(RNSBlurEffectStyleSystemUltraThinMaterialLight),
-    @"systemThinMaterialLight" : @(RNSBlurEffectStyleSystemThinMaterialLight),
-    @"systemMaterialLight" : @(RNSBlurEffectStyleSystemMaterialLight),
-    @"systemThickMaterialLight" : @(RNSBlurEffectStyleSystemThickMaterialLight),
-    @"systemChromeMaterialLight" : @(RNSBlurEffectStyleSystemChromeMaterialLight),
-    @"systemUltraThinMaterialDark" : @(RNSBlurEffectStyleSystemUltraThinMaterialDark),
-    @"systemThinMaterialDark" : @(RNSBlurEffectStyleSystemThinMaterialDark),
-    @"systemMaterialDark" : @(RNSBlurEffectStyleSystemMaterialDark),
-    @"systemThickMaterialDark" : @(RNSBlurEffectStyleSystemThickMaterialDark),
-    @"systemChromeMaterialDark" : @(RNSBlurEffectStyleSystemChromeMaterialDark),
-  }];
-#endif
-  return blurEffects;
-}
-
-RCT_ENUM_CONVERTER(RNSBlurEffectStyle, ([self blurEffectsForIOSVersion]), RNSBlurEffectStyleSystemDefault, integerValue)
-
-RCT_ENUM_CONVERTER(
-    RNSOptionalBoolean,
-    (@{
-      @"undefined" : @(RNSOptionalBooleanUndefined),
-      @"true" : @(RNSOptionalBooleanTrue),
-      @"false" : @(RNSOptionalBooleanFalse),
-    }),
-    RNSOptionalBooleanUndefined,
-    integerValue)
-
-RCT_ENUM_CONVERTER(
-    RNSScrollEdgeEffect,
-    (@{
-      @"automatic" : @(RNSScrollEdgeEffectAutomatic),
-      @"hard" : @(RNSScrollEdgeEffectHard),
-      @"soft" : @(RNSScrollEdgeEffectSoft),
-      @"hidden" : @(RNSScrollEdgeEffectHidden),
-    }),
-    RNSScrollEdgeEffectAutomatic,
-    integerValue)
-
-@end
-
-#endif // !RCT_NEW_ARCH_ENABLED
+// This file is intentionally empty — all content was Paper-only and has been removed
+// as part of the Paper architecture removal. The file will be deleted at the very end of the removal.

ios/RCTImageComponentView+RNSScreenStackHeaderConfig.h

@@ -1,6 +1,6 @@
 #pragma once
 
-#ifdef RCT_NEW_ARCH_ENABLED
+#if defined(__cplusplus)
 
 #include <React/RCTImageComponentView.h>
 
@@ -10,4 +10,4 @@
 
 @end
 
-#endif // RCT_NEW_ARCH_ENABLED
+#endif // __cplusplus

ios/RCTImageComponentView+RNSScreenStackHeaderConfig.mm

@@ -1,5 +1,3 @@
-#ifdef RCT_NEW_ARCH_ENABLED
-
 #include "RCTImageComponentView+RNSScreenStackHeaderConfig.h"
 
 @implementation RCTImageComponentView (RNSScreenStackHeaderConfig)
@@ -10,5 +8,3 @@ - (UIImage *)image
 }
 
 @end
-
-#endif // RCT_NEW_ARCH_ENABLED

ios/RNSConvert.h

@@ -1,18 +1,18 @@
 #pragma once
 
 #import <UIKit/UIKit.h>
-#ifdef RCT_NEW_ARCH_ENABLED
+#if defined(__cplusplus)
 #import <react/renderer/components/rnscreens/Props.h>
-#endif // RCT_NEW_ARCH_ENABLED
+#endif // __cplusplus
 #import "RNSEnums.h"
 
-#ifdef RCT_NEW_ARCH_ENABLED
+#if defined(__cplusplus)
 namespace react = facebook::react;
-#endif // RCT_NEW_ARCH_ENABLED
+#endif // __cplusplus
 
 @interface RNSConvert : NSObject
 
-#ifdef RCT_NEW_ARCH_ENABLED
+#if defined(__cplusplus)
 
 + (UISemanticContentAttribute)UISemanticContentAttributeFromCppEquivalent:
     (react::RNSScreenStackHeaderConfigDirection)direction;
@@ -71,7 +71,7 @@ namespace react = facebook::react;
     (react::RNSScreenTopScrollEdgeEffect)edgeEffect;
 + (id)idFromFollyDynamic:(const folly::dynamic &)dyn;
 
-#endif // RCT_NEW_ARCH_ENABLED
+#endif // __cplusplus
 
 /// This method fails (by assertion) when `blurEffect == RNSBlurEffectStyleNone` or `blurEffect ==
 /// RNSBlurEffectStyleSystemDefault` which have no counter parts in the UIKit types.

ios/RNSConvert.mm

@@ -1,13 +1,7 @@
 #import "RNSConvert.h"
 #import <React/RCTLog.h>
 
-#ifndef RCT_NEW_ARCH_ENABLED
-#import <React/RCTAssert.h>
-#endif // !RCT_NEW_ARCH_ENABLED
-
 @implementation RNSConvert
-
-#ifdef RCT_NEW_ARCH_ENABLED
 + (UISemanticContentAttribute)UISemanticContentAttributeFromCppEquivalent:
     (react::RNSScreenStackHeaderConfigDirection)direction
 {
@@ -386,17 +380,9 @@ + (id)idFromFollyDynamic:(const folly::dynamic &)dyn
   return nil;
 }
 
-#endif // RCT_NEW_ARCH_ENABLED
-
 + (UIBlurEffectStyle)tryConvertRNSBlurEffectStyleToUIBlurEffectStyle:(RNSBlurEffectStyle)blurEffect
 {
-#ifdef RCT_NEW_ARCH_ENABLED
   react_native_assert(blurEffect != RNSBlurEffectStyleNone && blurEffect != RNSBlurEffectStyleSystemDefault);
-#else
-  RCTAssert(
-      blurEffect != RNSBlurEffectStyleNone && blurEffect != RNSBlurEffectStyleSystemDefault,
-      @"RNSBlurEffectStyleNone and RNSBlurEffectStyleSystemDefault variants are not convertible to UIBlurEffectStyle");
-#endif // RCT_NEW_ARCH_ENABLED
 
   // Cast safety: RNSBlurEffectStyle is defined in such way that its values map 1:1 with
   // UIBlurEffectStyle, except RNSBlurEffectStyleNone and RNSBlurEffectStyleSystemDefault which are excluded above.

ios/RNSFullWindowOverlay.h

@@ -1,17 +1,11 @@
 #pragma once
 
 #import <React/RCTViewManager.h>
+#import "RNSReactBaseView.h"
 
-#ifdef RCT_NEW_ARCH_ENABLED
-#import <React/RCTViewComponentView.h>
-#else
-#import <React/RCTInvalidating.h>
-#import <React/RCTView.h>
-#endif
-
-#ifdef RCT_NEW_ARCH_ENABLED
+#if defined(__cplusplus)
 namespace react = facebook::react;
-#endif // RCT_NEW_ARCH_ENABLED
+#endif // __cplusplus
 
 @interface RNSFullWindowOverlayManager : RCTViewManager
 
@@ -21,18 +15,13 @@ namespace react = facebook::react;
 
 @end
 
-@interface RNSFullWindowOverlay :
-#ifdef RCT_NEW_ARCH_ENABLED
-    RCTViewComponentView
-#else
-    RCTView <RCTInvalidating>
-#endif // RCT_NEW_ARCH_ENABLED
+@interface RNSFullWindowOverlay : RNSReactBaseView
 
 @property (nonatomic) BOOL accessibilityContainerViewIsModal;
 
-#ifdef RCT_NEW_ARCH_ENABLED
+#if defined(__cplusplus)
 @property (nonatomic) react::LayoutMetrics oldLayoutMetrics;
 @property (nonatomic) react::LayoutMetrics newLayoutMetrics;
-#endif // RCT_NEW_ARCH_ENABLED
+#endif // __cplusplus
 
 @end

ios/RNSFullWindowOverlay.mm

@@ -3,17 +3,13 @@
 #import "RNSDefines.h"
 #import "RNSFullWindowOverlay.h"
 
-#ifdef RCT_NEW_ARCH_ENABLED
 #import <React/RCTConversions.h>
 #import <React/RCTFabricComponentsPlugins.h>
 #import <React/RCTSurfaceTouchHandler.h>
 #import <react/renderer/components/rnscreens/ComponentDescriptors.h>
 #import <react/renderer/components/rnscreens/Props.h>
 #import <react/renderer/components/rnscreens/RCTComponentViewHelpers.h>
 #import <rnscreens/RNSFullWindowOverlayComponentDescriptor.h>
-#else
-#import <React/RCTTouchHandler.h>
-#endif // RCT_NEW_ARCH_ENABLED
 
 @implementation RNSFullWindowOverlayContainer
 
@@ -70,14 +66,9 @@ - (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
 @end
 
 @implementation RNSFullWindowOverlay {
-  __weak RCTBridge *_bridge;
   RNSFullWindowOverlayContainer *_container;
   CGRect _reactFrame;
-#ifdef RCT_NEW_ARCH_ENABLED
   RCTSurfaceTouchHandler *_touchHandler;
-#else
-  RCTTouchHandler *_touchHandler;
-#endif // RCT_NEW_ARCH_ENABLED
 }
 
 // Needed because of this: https://github.com/facebook/react-native/pull/37274
@@ -86,7 +77,6 @@ + (void)load
   [super load];
 }
 
-#ifdef RCT_NEW_ARCH_ENABLED
 - (instancetype)init
 {
   if (self = [super init]) {
@@ -96,17 +86,6 @@ - (instancetype)init
   }
   return self;
 }
-#else
-- (instancetype)initWithBridge:(RCTBridge *)bridge
-{
-  if (self = [super init]) {
-    _bridge = bridge;
-    [self initCommonProps];
-  }
-
-  return self;
-}
-#endif // RCT_NEW_ARCH_ENABLED
 
 - (void)initCommonProps
 {
@@ -154,11 +133,7 @@ - (void)didMoveToSuperview
       UIAccessibilityPostNotification(UIAccessibilityLayoutChangedNotification, _container);
     }
     if (_touchHandler == nil) {
-#ifdef RCT_NEW_ARCH_ENABLED
       _touchHandler = [RCTSurfaceTouchHandler new];
-#else
-      _touchHandler = [[RCTTouchHandler alloc] initWithBridge:_bridge];
-#endif
     }
     [_touchHandler attachToView:_container];
 
@@ -193,7 +168,6 @@ - (void)maybeShow
   }
 }
 
-#ifdef RCT_NEW_ARCH_ENABLED
 #pragma mark - Fabric Specific
 
 + (react::ComponentDescriptorProvider)componentDescriptorProvider
@@ -228,7 +202,7 @@ - (void)updateLayoutMetrics:(react::LayoutMetrics const &)layoutMetrics
 {
   CGRect frame = RCTCGRectFromRect(layoutMetrics.frame);
 
-  // Due to view flattening on new architecture there are situations
+  // Due to view flattening there are situations
   // when we receive frames with origin different from (0, 0).
   // We account for this frame manipulation in shadow node by setting
   // RootNodeKind trait for the shadow node making state consistent
@@ -253,44 +227,13 @@ - (void)updateProps:(const facebook::react::Props::Shared &)props
   [super updateProps:props oldProps:oldProps];
 }
 
-#else
-#pragma mark - Paper specific
-
-- (void)reactSetFrame:(CGRect)frame
-{
-  _reactFrame = frame;
-  [_container setFrame:frame];
-}
-
-- (void)invalidate
-{
-  [_container removeFromSuperview];
-  _container = nil;
-}
-
-#endif // RCT_NEW_ARCH_ENABLED
-
 @end
 
-#ifdef RCT_NEW_ARCH_ENABLED
 Class<RCTComponentViewProtocol> RNSFullWindowOverlayCls(void)
 {
   return RNSFullWindowOverlay.class;
 }
-#endif // RCT_NEW_ARCH_ENABLED
 
 @implementation RNSFullWindowOverlayManager
 
-RCT_EXPORT_MODULE()
-
-RCT_EXPORT_VIEW_PROPERTY(accessibilityContainerViewIsModal, BOOL)
-
-#ifdef RCT_NEW_ARCH_ENABLED
-#else
-- (UIView *)view
-{
-  return [[RNSFullWindowOverlay alloc] initWithBridge:self.bridge];
-}
-#endif // RCT_NEW_ARCH_ENABLED
-
 @end