refactor(iOS): hide any C++ symbols from native-public API (#99)

This PR aims to hide any references to C++ symbols from the public API,
*when consumed in C mode* while building Swift module.

I add some indirection layers & hide all C++ headers from public API.
For details see below (it's best to go commit by commit) 👇🏻

> [!note]
> I do wonder why the compiler does not complain about rest of the files
- we use C++ apis in "old" implementation excessively. My guess would
be, that we're kinda lucky in similar fashion to mapbox - most likely
RCT_NEW_ARCH_ENABLED is not defined for Swift compiler & all our usage
of C++ symbols is behind that flag. I guess it's fine? It'll become a
problem, when we get rid of Paper & remove the flag usage, however it is
likely that we won't do that for the old impl (it'll be simply replaced
by Fabric-only new impl).

## Testing

The FabricExample builds fine in "regular setup". When building with
static frameworks it fails due to gesture handler 👇🏻


![image](https://github.com/user-attachments/assets/6388cb23-a355-4c48-9b4a-5f4b4ca7fcd5)

If GH is removed, the build passes.

Build for dynamic frameworks (tested only w/o GH) also passes locally.

I can try bumping GH in follow up 


<details>

<summary>Details of what changed (commits & descriptions)</summary>

- **Migrate event emitting code of BottomTabsHost to dedicated class**
  This is a start of migration of library-wide refactor of our
  Objective-C++ code. We need to get rid of any references / imports
  of any C++ code / symbols in our header to make them consumable by our
  Swift implementation files.
  
  This particular commit migrates raw references to react event emitter
  into calls to wrapper object RNSBottomTabsHostEventEmitter.
  

- **Add RNSReactBaseView**
This class is meant to serve as a proxy for `RCTViewComponentView` for
our
  component classes to inherit from.
  
  When needed this can be extended for old architecture.
  
  For views that do not need inheritance from `RCTViewComponentView` and
  `UIView<RCTComponentViewProtocol>` is enough separate proxy base class
  should be created.
  

- **Use new RNSReactBaseView for RNSBottomTabsHostComponentView**
  This eliminates error with inheriting from "not existing" type.
  Type forward declaration is not enough unfortunately.
  

- **Remove forward declaration for OnNativeFocusChangePayload**
  Unneeded. Can add it back, when we'll have multiple types, so that
the main definition of RNSBottomTabsHostEventEmitter is not obfuscated.

- **Define rnscreens::conversion namespace & nested functions only when
in C++ mode**
I believe this flag is not needed in implementation file, since .mm will
be always compiled with C++.

- **Use C-style struct defining syntax when not in C++ mode** 
I'm not confident in this change. Original code triggered an issue, that
the symbol was missing. It was obviously due to struct definition syntax
  differences between C & C++. Therefore this commit splits C++ & C
  definitions.

  My main doubts are about memory layout of these structs & if these can
  be different & in this can lead to an runtime UB at any point.
  
  For now assuming that the type exposed to Swift here won't really
  matter.
  
- **Make RNSStackScreenComponentView inherit from RNSReactBaseView**

- **Make RNSScreenStackHostComponentView inherit from RNSReactBaseView**
Also remove imports introducing any C++ symbols from .h file.

- **Fix incorrect extension name for RNSBottomTabsScreenEventEmitter**

- **Make all C++ headers "project" & set this on "common" subspec**
Both {private,project}_header_files work here fine (in terms of project
build), however from semantic standpoint "project" make more sense here.
See nice summary of these two options:
https://stackoverflow.com/a/8016333/8635522.
Our C++ pieces are not meant to be consumed by any other target than us.
We do not need to expose these symbols for anyone & we won't be
consuming
  them in our Swift code. We might relax this later, when needed.
  
  Second thing is that this commit moves the setting from main spec to
subspec. It made more sense for me, since the sources in the `common` &
`cpp`
  directories belong to the subspec.
  
  At last - w/o this change build of Swift module will fail, complaining
  that it does not understand C++ symbols.

- Fix issue with imports inside nullability audited region

- **Make all our Swift symbols & method referenced in Objective-C
public**
  Seems that this is requried for the symbols to be visible in
Objective-C. This has obvious downsides - we leak unnecessary symbols to
the public API, but this must suffice for now. We can look for a way to
  tighten things up later.
  
See reference:
https://silverhammermba.github.io/blog/2020/02/26/swift-and-obj-c


</details>

Author: kkafar

FabricExample/ios/FabricExample.xcodeproj/project.pbxproj

@@ -7,10 +7,10 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
-		0C80B921A6F3F58F76C31292 /* libPods-FabricExample.a in Frameworks */ = {isa = PBXBuildFile; fileRef = 5DCACB8F33CDC322A6C60F78 /* libPods-FabricExample.a */; };
 		13B07FBF1A68108700A75B9A /* Images.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 13B07FB51A68108700A75B9A /* Images.xcassets */; };
 		4338CA5B47FD1D3579126EBC /* PrivacyInfo.xcprivacy in Resources */ = {isa = PBXBuildFile; fileRef = 06C4D147D69C731B2F1541AC /* PrivacyInfo.xcprivacy */; };
 		81AB9BB82411601600AC10FF /* LaunchScreen.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = 81AB9BB72411601600AC10FF /* LaunchScreen.storyboard */; };
+		837C91B4642520B4D152E2A1 /* libPods-FabricExample.a in Frameworks */ = {isa = PBXBuildFile; fileRef = 67EDC5A0C3417BC3A60E3943 /* libPods-FabricExample.a */; };
 		EBA0179C2D12EF04006DCC81 /* AppDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = EBA0179B2D12EF04006DCC81 /* AppDelegate.swift */; };
 /* End PBXBuildFile section */
 
@@ -21,7 +21,7 @@
 		13B07FB61A68108700A75B9A /* Info.plist */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.plist.xml; name = Info.plist; path = FabricExample/Info.plist; sourceTree = "<group>"; };
 		3B4392A12AC88292D35C810B /* Pods-FabricExample.debug.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-FabricExample.debug.xcconfig"; path = "Target Support Files/Pods-FabricExample/Pods-FabricExample.debug.xcconfig"; sourceTree = "<group>"; };
 		5709B34CF0A7D63546082F79 /* Pods-FabricExample.release.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-FabricExample.release.xcconfig"; path = "Target Support Files/Pods-FabricExample/Pods-FabricExample.release.xcconfig"; sourceTree = "<group>"; };
-		5DCACB8F33CDC322A6C60F78 /* libPods-FabricExample.a */ = {isa = PBXFileReference; explicitFileType = archive.ar; includeInIndex = 0; path = "libPods-FabricExample.a"; sourceTree = BUILT_PRODUCTS_DIR; };
+		67EDC5A0C3417BC3A60E3943 /* libPods-FabricExample.a */ = {isa = PBXFileReference; explicitFileType = archive.ar; includeInIndex = 0; path = "libPods-FabricExample.a"; sourceTree = BUILT_PRODUCTS_DIR; };
 		81AB9BB72411601600AC10FF /* LaunchScreen.storyboard */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = file.storyboard; name = LaunchScreen.storyboard; path = FabricExample/LaunchScreen.storyboard; sourceTree = "<group>"; };
 		EB76649F2D13010D00B432B5 /* FabricExample-Bridging-Header.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "FabricExample-Bridging-Header.h"; sourceTree = "<group>"; };
 		EBA0179B2D12EF04006DCC81 /* AppDelegate.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppDelegate.swift; sourceTree = "<group>"; };
@@ -33,7 +33,7 @@
 			isa = PBXFrameworksBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
-				0C80B921A6F3F58F76C31292 /* libPods-FabricExample.a in Frameworks */,
+				837C91B4642520B4D152E2A1 /* libPods-FabricExample.a in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -57,7 +57,7 @@
 			isa = PBXGroup;
 			children = (
 				ED297162215061F000B7C4FE /* JavaScriptCore.framework */,
-				5DCACB8F33CDC322A6C60F78 /* libPods-FabricExample.a */,
+				67EDC5A0C3417BC3A60E3943 /* libPods-FabricExample.a */,
 			);
 			name = Frameworks;
 			sourceTree = "<group>";
@@ -366,6 +366,17 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
+				HEADER_SEARCH_PATHS = (
+					"$(inherited)",
+					"${PODS_CONFIGURATION_BUILD_DIR}/ReactCommon/ReactCommon.framework/Headers",
+					"${PODS_CONFIGURATION_BUILD_DIR}/ReactCommon/ReactCommon.framework/Headers/react/nativemodule/core",
+					"${PODS_CONFIGURATION_BUILD_DIR}/ReactCommon-Samples/ReactCommon_Samples.framework/Headers",
+					"${PODS_CONFIGURATION_BUILD_DIR}/ReactCommon-Samples/ReactCommon_Samples.framework/Headers/platform/ios",
+					"${PODS_CONFIGURATION_BUILD_DIR}/React-Fabric/React_Fabric.framework/Headers/react/renderer/components/view/platform/cxx",
+					"${PODS_CONFIGURATION_BUILD_DIR}/React-NativeModulesApple/React_NativeModulesApple.framework/Headers",
+					"${PODS_CONFIGURATION_BUILD_DIR}/React-graphics/React_graphics.framework/Headers",
+					"${PODS_CONFIGURATION_BUILD_DIR}/React-graphics/React_graphics.framework/Headers/react/renderer/graphics/platform/ios",
+				);
 				IPHONEOS_DEPLOYMENT_TARGET = 13.4;
 				LD = "";
 				LDPLUSPLUS = "";
@@ -443,6 +454,17 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
+				HEADER_SEARCH_PATHS = (
+					"$(inherited)",
+					"${PODS_CONFIGURATION_BUILD_DIR}/ReactCommon/ReactCommon.framework/Headers",
+					"${PODS_CONFIGURATION_BUILD_DIR}/ReactCommon/ReactCommon.framework/Headers/react/nativemodule/core",
+					"${PODS_CONFIGURATION_BUILD_DIR}/ReactCommon-Samples/ReactCommon_Samples.framework/Headers",
+					"${PODS_CONFIGURATION_BUILD_DIR}/ReactCommon-Samples/ReactCommon_Samples.framework/Headers/platform/ios",
+					"${PODS_CONFIGURATION_BUILD_DIR}/React-Fabric/React_Fabric.framework/Headers/react/renderer/components/view/platform/cxx",
+					"${PODS_CONFIGURATION_BUILD_DIR}/React-NativeModulesApple/React_NativeModulesApple.framework/Headers",
+					"${PODS_CONFIGURATION_BUILD_DIR}/React-graphics/React_graphics.framework/Headers",
+					"${PODS_CONFIGURATION_BUILD_DIR}/React-graphics/React_graphics.framework/Headers/react/renderer/graphics/platform/ios",
+				);
 				IPHONEOS_DEPLOYMENT_TARGET = 13.4;
 				LD = "";
 				LDPLUSPLUS = "";

RNScreens.podspec

@@ -21,7 +21,6 @@ Pod::Spec.new do |s|
   s.platforms    = { :ios => min_supported_ios_version, :tvos => min_supported_tvos_version, :visionos => min_supported_visionos_version }
   s.source       = { :git => "https://github.com/software-mansion/react-native-screens.git", :tag => "#{s.version}" }
   s.source_files = source_files
-  s.project_header_files = "cpp/**/*.h" # Don't expose C++ headers publicly to allow importing framework into Swift files
   s.requires_arc = true
 
   s.pod_target_xcconfig = {
@@ -32,6 +31,7 @@ Pod::Spec.new do |s|
   if new_arch_enabled
     s.subspec "common" do |ss|
       ss.source_files         = ["common/cpp/**/*.{cpp,h}", "cpp/**/*.{cpp,h}"]
+      ss.project_header_files = "common/cpp/**/*.h", "cpp/**/*.h" # Don't expose C++ headers publicly to allow importing framework into Swift files
       ss.header_dir           = "rnscreens"
       ss.pod_target_xcconfig  = { "HEADER_SEARCH_PATHS" => "\"$(PODS_TARGET_SRCROOT)/common/cpp\"" }
     end

ios/bottom-tabs/RNSBottomTabsHostComponentView.h

@@ -1,7 +1,7 @@
-#import <React/RCTViewComponentView.h>
-#import <react/renderer/components/rnscreens/EventEmitters.h>
 #import "RNSBottomTabsHostComponentViewManager.h"
+#import "RNSBottomTabsHostEventEmitter.h"
 #import "RNSEnums.h"
+#import "RNSReactBaseView.h"
 #import "RNSScreenContainer.h"
 
 NS_ASSUME_NONNULL_BEGIN
@@ -16,7 +16,7 @@ NS_ASSUME_NONNULL_BEGIN
  * 2. provider of React state & props for the tab bar controller
  * 3. two way communication channel with React (commands & events)
  */
-@interface RNSBottomTabsHostComponentView : RCTViewComponentView <RNSScreenContainerDelegate>
+@interface RNSBottomTabsHostComponentView : RNSReactBaseView <RNSScreenContainerDelegate>
 
 @end
 
@@ -28,7 +28,7 @@ NS_ASSUME_NONNULL_BEGIN
 @property (nonatomic, strong, readonly, nullable) UIBlurEffect *tabBarBlurEffect;
 @property (nonatomic, strong, readonly, nullable) NSNumber *tabBarItemTitleFontSize;
 
-@property (nonatomic, readonly) bool experimental_controlNavigationStateInJS;
+@property (nonatomic, readonly) BOOL experimental_controlNavigationStateInJS;
 
 @end
 
@@ -37,13 +37,11 @@ NS_ASSUME_NONNULL_BEGIN
 @interface RNSBottomTabsHostComponentView ()
 
 /**
- * This pointer might be `nullptr`!  All this method does is a cast of the backing field inherited from
- * `RCTViewComponentView`. The nullability of this pointer is therefore determined by `_eventEmitter` lifecycle in the
- * super class.
+ * Use returned object to emit appropriate React Events to Element Tree.
  */
-- (std::shared_ptr<const facebook::react::RNSBottomTabsEventEmitter>)reactEventEmitter;
+- (nonnull RNSBottomTabsHostEventEmitter *)reactEventEmitter;
 
-- (bool)emitOnNativeFocusChangeRequestSelectedTabScreen:(nonnull RNSBottomTabsScreenComponentView *)tabScreen;
+- (BOOL)emitOnNativeFocusChangeRequestSelectedTabScreen:(nonnull RNSBottomTabsScreenComponentView *)tabScreen;
 
 @end
 

ios/bottom-tabs/RNSBottomTabsHostComponentView.mm

@@ -23,6 +23,8 @@ @implementation RNSBottomTabsHostComponentView {
   RNSTabBarController *_controller;
   RNSTabBarControllerDelegate *_controllerDelegate;
 
+  RNSBottomTabsHostEventEmitter *_Nonnull _reactEventEmitter;
+
   // RCTViewComponentView does not expose this field, therefore we maintain
   // it on our side.
   NSMutableArray<RNSBottomTabsScreenComponentView *> *_reactSubviews;
@@ -45,7 +47,9 @@ - (void)initState
   _controller = [[RNSTabBarController alloc] initWithTabsHostComponentView:self];
   _controllerDelegate = [RNSTabBarControllerDelegate new];
   _controller.delegate = _controllerDelegate;
+
   _reactSubviews = [NSMutableArray new];
+  _reactEventEmitter = [RNSBottomTabsHostEventEmitter new];
 
   _hasModifiedReactSubviewsInCurrentTransaction = NO;
   _needsTabBarAppearanceUpdate = NO;
@@ -108,18 +112,15 @@ - (void)markChildUpdated
 
 #pragma mark - React events
 
-- (std::shared_ptr<const react::RNSBottomTabsEventEmitter>)reactEventEmitter
+- (nonnull RNSBottomTabsHostEventEmitter *)reactEventEmitter
 {
-  return std::dynamic_pointer_cast<const react::RNSBottomTabsEventEmitter>(_eventEmitter);
+  RCTAssert(_reactEventEmitter != nil, @"[RNScreens] Attempt to access uninitialized _reactEventEmitter");
+  return _reactEventEmitter;
 }
 
-- (bool)emitOnNativeFocusChangeRequestSelectedTabScreen:(RNSBottomTabsScreenComponentView *)tabScreen
+- (BOOL)emitOnNativeFocusChangeRequestSelectedTabScreen:(RNSBottomTabsScreenComponentView *)tabScreen
 {
-  if (const auto eventEmitter = self.reactEventEmitter; eventEmitter != nullptr) {
-    eventEmitter->onNativeFocusChange({RCTStringFromNSString(tabScreen.tabKey)});
-    return true;
-  }
-  return false;
+  return [_reactEventEmitter emitOnNativeFocusChange:OnNativeFocusChangePayload{.tabKey = tabScreen.tabKey}];
 }
 
 #pragma mark - RCTViewComponentViewProtocol
@@ -182,6 +183,14 @@ - (void)updateProps:(const facebook::react::Props::Shared &)props
   [super updateProps:props oldProps:oldProps];
 }
 
+- (void)updateEventEmitter:(const facebook::react::EventEmitter::Shared &)eventEmitter
+{
+  [super updateEventEmitter:eventEmitter];
+
+  const auto &castedEventEmitter = std::static_pointer_cast<const react::RNSBottomTabsEventEmitter>(eventEmitter);
+  [_reactEventEmitter updateEventEmitter:castedEventEmitter];
+}
+
 - (void)finalizeUpdates:(RNComponentViewUpdateMask)updateMask
 {
   if (_needsTabBarAppearanceUpdate) {

ios/bottom-tabs/RNSBottomTabsHostEventEmitter.h

@@ -0,0 +1,40 @@
+#import <Foundation/Foundation.h>
+
+// Hide C++ symbols from C compiler used when building Swift module
+#if defined(__cplusplus)
+#import <react/renderer/components/rnscreens/EventEmitters.h>
+
+namespace react = facebook::react;
+#endif // __cplusplus
+
+NS_ASSUME_NONNULL_BEGIN
+
+#if defined(__cplusplus)
+struct OnNativeFocusChangePayload {
+  NSString *_Nonnull tabKey;
+};
+#else
+typedef struct {
+  NSString *_Nonnull tabKey;
+} OnNativeFocusChangePayload;
+#endif
+
+@interface RNSBottomTabsHostEventEmitter : NSObject
+
+- (BOOL)emitOnNativeFocusChange:(OnNativeFocusChangePayload)payload;
+
+@end
+
+#pragma mark - Hidden from Swift
+
+#if defined(__cplusplus)
+
+@interface RNSBottomTabsHostEventEmitter ()
+
+- (void)updateEventEmitter:(const std::shared_ptr<const react::RNSBottomTabsEventEmitter> &)emitter;
+
+@end
+
+#endif // __cplusplus
+
+NS_ASSUME_NONNULL_END

ios/bottom-tabs/RNSBottomTabsHostEventEmitter.mm

@@ -0,0 +1,37 @@
+#import "RNSBottomTabsHostEventEmitter.h"
+
+#import <React/RCTConversions.h>
+#import <React/RCTLog.h>
+#import <react/renderer/components/rnscreens/EventEmitters.h>
+
+namespace react = facebook::react;
+
+@implementation RNSBottomTabsHostEventEmitter {
+  std::shared_ptr<const react::RNSBottomTabsEventEmitter> _reactEventEmitter;
+}
+
+- (instancetype)init
+{
+  if (self = [super init]) {
+    _reactEventEmitter = nullptr;
+  }
+  return self;
+}
+
+- (void)updateEventEmitter:(const std::shared_ptr<const react::RNSBottomTabsEventEmitter> &)emitter
+{
+  _reactEventEmitter = emitter;
+}
+
+- (BOOL)emitOnNativeFocusChange:(OnNativeFocusChangePayload)payload
+{
+  if (_reactEventEmitter != nullptr) {
+    _reactEventEmitter->onNativeFocusChange({.tabKey = RCTStringFromNSString(payload.tabKey)});
+    return true;
+  } else {
+    RCTLogWarn(@"[RNScreens] Skipped OnNativeFocusChange event emission due to nullish emitter");
+    return false;
+  }
+}
+
+@end

ios/bottom-tabs/RNSBottomTabsScreenComponentView.h

@@ -1,5 +1,5 @@
-#import <React/RCTViewComponentView.h>
-#import <react/renderer/components/rnscreens/EventEmitters.h>
+#import "RNSBottomTabsScreenEventEmitter.h"
+#import "RNSReactBaseView.h"
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -10,7 +10,7 @@ NS_ASSUME_NONNULL_BEGIN
  * Component view with react managed lifecycle. This view serves as root view in hierarchy
  * of a particular tab.
  */
-@interface RNSBottomTabsScreenComponentView : RCTViewComponentView
+@interface RNSBottomTabsScreenComponentView : RNSReactBaseView
 
 /**
  * View controller responsible for managing tab represented by this component view.
@@ -43,24 +43,12 @@ NS_ASSUME_NONNULL_BEGIN
 
 #pragma mark - Events
 
-/**
- * These methods can be called to send an appropriate event to ElementTree.
- * Returned value denotes whether the event has been successfully dispatched to React event pipeline.
- * The returned value of `true` does not mean, that the event has been successfully delivered.
- */
 @interface RNSBottomTabsScreenComponentView ()
 
 /**
- * This pointer might be `nullptr`!  All this method does is a cast of the backing field inherited from
- * `RCTViewComponentView`. The nullability of this pointer is therefore determined by `_eventEmitter` lifecycle in the
- * super class.
+ * Use returned object to emit appropriate React Events to Element Tree.
  */
-- (std::shared_ptr<const facebook::react::RNSBottomTabsScreenEventEmitter>)reactEventEmitter;
-
-- (bool)emitOnWillAppear;
-- (bool)emitOnDidAppear;
-- (bool)emitOnWillDisappear;
-- (bool)emitOnDidDisappear;
+- (nonnull RNSBottomTabsScreenEventEmitter *)reactEventEmitter;
 
 @end
 

ios/bottom-tabs/RNSBottomTabsScreenComponentView.mm

@@ -15,6 +15,8 @@
 @implementation RNSBottomTabsScreenComponentView {
   RNSTabsScreenViewController *_controller;
   RNSBottomTabsHostComponentView *__weak _Nullable _reactSuperview;
+
+  RNSBottomTabsScreenEventEmitter *_Nonnull _reactEventEmitter;
 }
 
 - (instancetype)initWithFrame:(CGRect)frame
@@ -34,6 +36,8 @@ - (void)initState
   _controller.view = self;
 
   _reactSuperview = nil;
+  _reactEventEmitter = [RNSBottomTabsScreenEventEmitter new];
+
   [self resetProps];
 }
 
@@ -54,45 +58,10 @@ - (nullable RNSBottomTabsHostComponentView *)reactSuperview
 
 #pragma mark - Events
 
-- (std::shared_ptr<const facebook::react::RNSBottomTabsScreenEventEmitter>)reactEventEmitter
-{
-  return std::dynamic_pointer_cast<const facebook::react::RNSBottomTabsScreenEventEmitter>(_eventEmitter);
-}
-
-- (bool)emitOnWillAppear
+- (nonnull RNSBottomTabsScreenEventEmitter *)reactEventEmitter
 {
-  if (const auto eventEmitter = self.reactEventEmitter; eventEmitter != nullptr) {
-    eventEmitter->onWillAppear({});
-    return true;
-  }
-  return false;
-}
-
-- (bool)emitOnDidAppear
-{
-  if (const auto eventEmitter = self.reactEventEmitter; eventEmitter != nullptr) {
-    eventEmitter->onDidAppear({});
-    return true;
-  }
-  return false;
-}
-
-- (bool)emitOnWillDisappear
-{
-  if (const auto eventEmitter = self.reactEventEmitter; eventEmitter != nullptr) {
-    eventEmitter->onWillDisappear({});
-    return true;
-  }
-  return false;
-}
-
-- (bool)emitOnDidDisappear
-{
-  if (const auto eventEmitter = self.reactEventEmitter; eventEmitter != nullptr) {
-    eventEmitter->onDidDisappear({});
-    return true;
-  }
-  return false;
+  RCTAssert(_reactEventEmitter != nil, @"[RNScreens] Attempt to access uninitialized _reactEventEmitter");
+  return _reactEventEmitter;
 }
 
 - (nullable RNSTabBarController *)findTabBarController
@@ -158,6 +127,13 @@ - (void)updateLayoutMetrics:(const facebook::react::LayoutMetrics &)layoutMetric
   [super updateLayoutMetrics:layoutMetrics oldLayoutMetrics:oldLayoutMetrics];
 }
 
+- (void)updateEventEmitter:(const facebook::react::EventEmitter::Shared &)eventEmitter
+{
+  [super updateEventEmitter:eventEmitter];
+  [_reactEventEmitter
+      updateEventEmitter:std::static_pointer_cast<const react::RNSBottomTabsScreenEventEmitter>(eventEmitter)];
+}
+
 - (void)mountChildComponentView:(UIView<RCTComponentViewProtocol> *)childComponentView index:(NSInteger)index
 {
   NSLog(@"TabScreen [%ld] mount [%ld] at %ld", self.tag, childComponentView.tag, index);