fix: apply logic from paper on Fabric

ios/RNSScreen.mm

@@ -34,6 +34,9 @@ @interface RNSScreenView ()
 @implementation RNSScreenView {
   __weak RCTBridge *_bridge;
 #ifdef RN_FABRIC_ENABLED
+// we recreate the behavior of `reactSetFrame` on new architecture
+    facebook::react::LayoutMetrics _oldLayoutMetrics;
+    facebook::react::LayoutMetrics _newLayoutMetrics;
   RCTSurfaceTouchHandler *_touchHandler;
   facebook::react::RNSScreenShadowNode::ConcreteState::Shared _state;
 #else
@@ -288,6 +291,7 @@ - (void)notifyWillAppear
     std::dynamic_pointer_cast<const facebook::react::RNSScreenEventEmitter>(_eventEmitter)
         ->onWillAppear(facebook::react::RNSScreenEventEmitter::OnWillAppear{});
   }
+    [self updateLayoutMetrics:_layoutMetrics oldLayoutMetrics:_oldLayoutMetrics];
 #else
   if (self.onWillAppear) {
     self.onWillAppear(nil);
@@ -444,6 +448,11 @@ - (void)prepareForRecycle
   // TODO: Make sure that there is no edge case when this should be uncommented
   // _controller=nil;
   _dismissed = NO;
+  // we don't reset the transform of view at the end of custom transitions,
+  // so in order not to add code to all transitions, we just reset it here.
+  // Maybe it would be better to do it in each animation since we could change other
+  // view props there too and they need to be reset due to view recycling.
+  self.transform = CGAffineTransformIdentity;
   _state.reset();
 }
 
@@ -520,6 +529,24 @@ - (void)updateState:(facebook::react::State::Shared const &)state
   _state = std::static_pointer_cast<const facebook::react::RNSScreenShadowNode::ConcreteState>(state);
 }
 
+ - (void)updateLayoutMetrics:(const facebook::react::LayoutMetrics &)layoutMetrics
+            oldLayoutMetrics:(const facebook::react::LayoutMetrics &)oldLayoutMetrics
+ {
+     _layoutMetrics = layoutMetrics;
+     _oldLayoutMetrics = oldLayoutMetrics;
+     UIViewController *parentVC = self.reactViewController.parentViewController;
+     if (parentVC != nil && ![parentVC isKindOfClass:[RNScreensNavigationController class]]) {
+         [super updateLayoutMetrics:layoutMetrics oldLayoutMetrics:oldLayoutMetrics];
+     }
+     // when screen is mounted under RNScreensNavigationController it's size is controller
+     // by the navigation controller itself. That is, it is set to fill space of
+     // the controller. In that case we ignore react layout system from managing
+     // the screen dimensions and we wait for the screen VC to update and then we
+     // pass the dimensions to ui view manager to take into account when laying out
+     // subviews
+     // Explanation taken from `reactSetFrame`, which is old arch equivalent of this code.
+ }
+
 #pragma mark - Paper specific
 #else
 
@@ -614,9 +641,7 @@ - (void)invalidate
 @implementation RNSScreen {
   __weak id _previousFirstResponder;
   CGRect _lastViewFrame;
-#ifdef RN_FABRIC_ENABLED
   RNSScreenView *_initialView;
-#else
   UIView *_fakeView;
   CADisplayLink *_animationTimer;
   CGFloat _currentAlpha;
@@ -625,7 +650,6 @@ @implementation RNSScreen {
   int _dismissCount;
   BOOL _isSwiping;
   BOOL _shouldNotify;
-#endif
 }
 
 #pragma mark - Common
@@ -648,12 +672,12 @@ - (instancetype)initWithView:(UIView *)view
 - (void)viewWillAppear:(BOOL)animated
 {
   [super viewWillAppear:animated];
+  if (!_isSwiping) {
 #ifdef RN_FABRIC_ENABLED
-  [RNSScreenWindowTraits updateWindowTraits];
   [_initialView notifyWillAppear];
 #else
-  if (!_isSwiping) {
     [((RNSScreenView *)self.view) notifyWillAppear];
+#endif
     if (self.transitionCoordinator.isInteractive) {
       // we started dismissing with swipe gesture
       _isSwiping = YES;
@@ -663,26 +687,28 @@ - (void)viewWillAppear:(BOOL)animated
     // The _isSwiping is still true, but we don't want to notify then
     _shouldNotify = NO;
   }
-
+#ifdef RN_FABRIC_ENABLED
+#else
   [self hideHeaderIfNecessary];
-
+#endif
   // as per documentation of these methods
   _goingForward = [self isBeingPresented] || [self isMovingToParentViewController];
 
   [RNSScreenWindowTraits updateWindowTraits];
   if (_shouldNotify) {
     _closing = NO;
+#ifdef RN_FABRIC_ENABLED
+#else
     [self notifyTransitionProgress:0.0 closing:_closing goingForward:_goingForward];
     [self setupProgressNotification];
-  }
 #endif
+  }
 }
 
 - (void)viewWillDisappear:(BOOL)animated
 {
   [super viewWillDisappear:animated];
 #ifdef RN_FABRIC_ENABLED
-  [_initialView notifyWillDisappear];
 #else
   if (!self.transitionCoordinator.isInteractive) {
     // user might have long pressed ios 14 back button item,
@@ -696,10 +722,15 @@ - (void)viewWillDisappear:(BOOL)animated
   } else {
     _dismissCount = 1;
   }
+#endif
 
   // same flow as in viewWillAppear
   if (!_isSwiping) {
+#ifdef RN_FABRIC_ENABLED
+  [_initialView notifyWillDisappear];
+#else
     [((RNSScreenView *)self.view) notifyWillDisappear];
+#endif
     if (self.transitionCoordinator.isInteractive) {
       _isSwiping = YES;
     }
@@ -712,35 +743,37 @@ - (void)viewWillDisappear:(BOOL)animated
 
   if (_shouldNotify) {
     _closing = YES;
+#ifdef RN_FABRIC_ENABLED
+#else
     [self notifyTransitionProgress:0.0 closing:_closing goingForward:_goingForward];
     [self setupProgressNotification];
-  }
 #endif
+  }
 }
 
 - (void)viewDidAppear:(BOOL)animated
 {
   [super viewDidAppear:animated];
+  if (!_isSwiping || _shouldNotify) {
+
 #ifdef RN_FABRIC_ENABLED
-  [_initialView notifyAppear];
+      [_initialView notifyAppear];
 #else
-  if (!_isSwiping || _shouldNotify) {
     // we are going forward or dismissing without swipe
     // or successfully swiped back
     [((RNSScreenView *)self.view) notifyAppear];
     [self notifyTransitionProgress:1.0 closing:NO goingForward:_goingForward];
+#endif
   }
 
   _isSwiping = NO;
   _shouldNotify = YES;
-#endif
 }
 
 - (void)viewDidDisappear:(BOOL)animated
 {
   [super viewDidDisappear:animated];
 #ifdef RN_FABRIC_ENABLED
-  [_initialView notifyDisappear];
   if (self.parentViewController == nil && self.presentingViewController == nil) {
     // screen dismissed, send event
     [_initialView notifyDismissedWithCount:1];
@@ -757,16 +790,21 @@ - (void)viewDidDisappear:(BOOL)animated
       [((RNSScreenView *)self.view) notifyDismissedWithCount:_dismissCount];
     }
   }
-
+#endif
   // same flow as in viewDidAppear
   if (!_isSwiping || _shouldNotify) {
+#ifdef RN_FABRIC_ENABLED
+      [_initialView notifyDisappear];
+#else
     [((RNSScreenView *)self.view) notifyDisappear];
     [self notifyTransitionProgress:1.0 closing:YES goingForward:_goingForward];
+#endif
   }
 
   _isSwiping = NO;
   _shouldNotify = YES;
-
+#ifdef RN_FABRIC_ENABLED
+#else
   [self traverseForScrollView:self.view];
 #endif
 }

ios/RNSScreenStack.mm

@@ -725,6 +725,32 @@ - (void)handleSwipe:(UIPanGestureRecognizer *)gestureRecognizer
     }
   }
 }
+
+- (id<UIViewControllerInteractiveTransitioning>)navigationController:(UINavigationController *)navigationController
+                         interactionControllerForAnimationController:
+                             (id<UIViewControllerAnimatedTransitioning>)animationController
+{
+  return _interactionController;
+}
+
+- (id<UIViewControllerInteractiveTransitioning>)interactionControllerForDismissal:
+    (id<UIViewControllerAnimatedTransitioning>)animator
+{
+  return _interactionController;
+}
+
+- (void)navigationController:(UINavigationController *)navigationController
+       didShowViewController:(UIViewController *)viewController
+                    animated:(BOOL)animated
+{
+#ifdef RN_FABRIC_ENABLED
+#else
+  if (self.onFinishTransitioning) {
+    self.onFinishTransitioning(nil);
+  }
+#endif
+  [RNSScreenWindowTraits updateWindowTraits];
+}
 #endif
 
 - (void)markChildUpdated
@@ -806,17 +832,31 @@ - (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer
   return [self isScrollViewPanGestureRecognizer:otherGestureRecognizer];
 }
 
-- (id<UIViewControllerInteractiveTransitioning>)navigationController:(UINavigationController *)navigationController
-                         interactionControllerForAnimationController:
-                             (id<UIViewControllerAnimatedTransitioning>)animationController
+- (void)insertReactSubview:(RNSScreenView *)subview atIndex:(NSInteger)atIndex
 {
-  return _interactionController;
+  if (![subview isKindOfClass:[RNSScreenView class]]) {
+    RCTLogError(@"ScreenStack only accepts children of type Screen");
+    return;
+  }
+  subview.reactSuperview = self;
+  [_reactSubviews insertObject:subview atIndex:atIndex];
 }
 
-- (id<UIViewControllerInteractiveTransitioning>)interactionControllerForDismissal:
-    (id<UIViewControllerAnimatedTransitioning>)animator
+- (void)removeReactSubview:(RNSScreenView *)subview
 {
-  return _interactionController;
+  subview.reactSuperview = nil;
+  [_reactSubviews removeObject:subview];
+}
+
+- (void)didUpdateReactSubviews
+{
+  // we need to wait until children have their layout set. At this point they don't have the layout
+  // set yet, however the layout call is already enqueued on ui thread. Enqueuing update call on the
+  // ui queue will guarantee that the update will run after layout.
+  dispatch_async(dispatch_get_main_queue(), ^{
+    self->_hasLayout = YES;
+    [self maybeAddToParentAndUpdateContainer];
+  });
 }
 
 #ifdef RN_FABRIC_ENABLED
@@ -907,43 +947,6 @@ - (void)prepareForRecycle
 #else
 #pragma mark - Paper specific
 
-- (void)navigationController:(UINavigationController *)navigationController
-       didShowViewController:(UIViewController *)viewController
-                    animated:(BOOL)animated
-{
-  if (self.onFinishTransitioning) {
-    self.onFinishTransitioning(nil);
-  }
-  [RNSScreenWindowTraits updateWindowTraits];
-}
-
-- (void)insertReactSubview:(RNSScreenView *)subview atIndex:(NSInteger)atIndex
-{
-  if (![subview isKindOfClass:[RNSScreenView class]]) {
-    RCTLogError(@"ScreenStack only accepts children of type Screen");
-    return;
-  }
-  subview.reactSuperview = self;
-  [_reactSubviews insertObject:subview atIndex:atIndex];
-}
-
-- (void)removeReactSubview:(RNSScreenView *)subview
-{
-  subview.reactSuperview = nil;
-  [_reactSubviews removeObject:subview];
-}
-
-- (void)didUpdateReactSubviews
-{
-  // we need to wait until children have their layout set. At this point they don't have the layout
-  // set yet, however the layout call is already enqueued on ui thread. Enqueuing update call on the
-  // ui queue will guarantee that the update will run after layout.
-  dispatch_async(dispatch_get_main_queue(), ^{
-    self->_hasLayout = YES;
-    [self maybeAddToParentAndUpdateContainer];
-  });
-}
-
 - (void)invalidate
 {
   _invalidated = YES;
@@ -954,6 +957,7 @@ - (void)invalidate
   [_controller willMoveToParentViewController:nil];
   [_controller removeFromParentViewController];
 }
+
 #endif // RN_FABRIC_ENABLED
 
 @end