feat(iOS): Handle interactiveContentPopGesture for iOS 26 (#3173)

## Description

Resolves
software-mansion/react-native-screens-labs#369,
might resolve
#3161,
reverts
#3141,
#3142

This PR attempts to enable interactiveContentPopGestureRecognizer for
iOS 26 to achieve native screen popping behavior. Until 26, the default
was to swipe from the edge of the screen. We had the option to do
fullscreen switch, which was controlled by a `fullScreenSwipeEnabled`
prop. Since the default behavior has changed, this prop, along with
`gestureResponseDistance`, is being ignored from now on.

New iOS allows for popping multiple screens almost at once, which we
still cannot support due to asynchronous nature of stack updates coming
from host to JS that would create a "feedback loop" in situation like
the following: host pops 1. screen + sends update, pops 2. screen +
sends update -> JS acknowledges 1. update + sends updated state -> host
gets 2. screen from JS and pushes it again. This PR attempts to block
more than 1 pop at once by removing interactions from the whole screen.
As a (desired) side effect, this also disables interactions on the
screen below the one that is popped until the transition finishes.

## Changes

- removed `RNSPanGestureRecognizer` from iOS 26 build and replace it
with native `interactiveContentPopGestureRecognizer`
- disabled all interactions when screens are in transition
- updated docs

## Test code and steps to reproduce

Use Test3173 to test swipe and interactions on bare screens API &
compare with any other test that uses react-navigation stack, i.e
Test3093. Use Test3093 with additional screenOptions:
```ts
{
        animation: 'slide_from_bottom',
        animationMatchesGesture: true,
}
```
to test custom animations on swipe back.

---------

Co-authored-by: Kacper Kafara <[email protected]>

Author: kmichalikk

apps/src/tests/Test3173.tsx

@@ -0,0 +1,71 @@
+import * as React from 'react';
+import { View, Text, Button } from 'react-native';
+import { Screen, ScreenStack, ScreenStackHeaderConfig } from '../../../src';
+import { useState } from 'react';
+import Colors from '../shared/styling/Colors';
+
+function HomeScreen({ add }: { add: () => void }) {
+  console.log('Render home');
+  return (
+    <View
+      style={{
+        flex: 1,
+        gap: 8,
+        alignItems: 'center',
+        justifyContent: 'center',
+        backgroundColor: Colors.RedLight40,
+      }}>
+      <Text>Home!</Text>
+      <Button
+        title="Next"
+        onPress={add}
+      />
+    </View>
+  );
+}
+
+function ProfileScreen({ add, idx }: { add: () => void, idx: number }) {
+  const colors = [Colors.BlueLight40, Colors.GreenLight40, Colors.YellowLight40];
+  const [colorIndex, setColorIndex] = useState(0);
+  console.log('Render another');
+  return (
+    <View
+      style={{
+        flex: 1,
+        gap: 8,
+        alignItems: 'center',
+        justifyContent: 'center',
+        backgroundColor: colors[colorIndex]
+      }}>
+      <Text>Another! #{idx}</Text>
+      <Button
+        title="More"
+        onPress={add}
+      />
+      <Button
+        title="Recolor"
+        onPress={() => setColorIndex(i => (i+1) % 3)}
+      />
+    </View>
+  );
+}
+
+const App = () => {
+  const [count, setCount] = React.useState(0);
+
+  return (
+    <ScreenStack style={{ flex: 1 }}>
+      <Screen key='home' activityState={2} isNativeStack onAppear={() => {setCount(0)}}>
+        <ScreenStackHeaderConfig title='Home'/>
+        <HomeScreen add={() => setCount(n => n+1)}/>
+      </Screen>
+      { Array.from({length: count}).map((_, i) => (
+        <Screen key={`prof${i}`} activityState={2} isNativeStack>
+          <ScreenStackHeaderConfig title={'Another #' + (i+1)}/>
+          <ProfileScreen add={() => setCount(n => n+1)} idx={i+1}/>
+        </Screen>
+      )) }
+    </ScreenStack>
+  );
+};
+export default App;

apps/src/tests/index.ts

@@ -148,6 +148,7 @@ export { default as Test3093 } from './Test3093';
 export { default as Test3111 } from './Test3111';
 export { default as Test3115 } from './Test3115';
 export { default as Test3168 } from './Test3168';
+export { default as Test3173 } from './Test3173';
 export { default as TestScreenAnimation } from './TestScreenAnimation';
 export { default as TestScreenAnimationV5 } from './TestScreenAnimationV5';
 export { default as TestHeader } from './TestHeader';

guides/GUIDE_FOR_LIBRARY_AUTHORS.md

@@ -55,12 +55,15 @@ Defaults to `false`. When `enableFreeze()` is run at the top of the application
 ### `fullScreenSwipeEnabled` (iOS only)
 
 Boolean indicating whether the swipe gesture should work on whole screen. Swiping with this option results in the same transition animation as `simple_push` by default. It can be changed to other custom animations with `customAnimationOnSwipe` prop, but default iOS swipe animation is not achievable due to usage of custom recognizer. Defaults to `false`.
+IMPORTANT: Starting from iOS 26, full screen swipe is handled by native recognizer, and this prop is ignored.
 
 ### `fullScreenSwipeShadowEnabled` (iOS only)
 
 Boolean indicating whether the full screen dismiss gesture has shadow under view during transition. The gesture uses custom transition and thus
 doesn't have a shadow by default. When enabled, a custom shadow view is added during the transition which tries to mimic the
 default iOS shadow. Defaults to `true`.
+IMPORTANT: Starting from iOS 26, full screen swipe is handled by native recognizer, and this prop is ignored. We still fallback
+to the legacy implementation when when handling custom animations, but we assume `true` for shadows.
 
 ### `gestureEnabled` (iOS only)
 
@@ -69,6 +72,7 @@ When set to `false` the back swipe gesture will be disabled. The default value i
 #### `gestureResponseDistance` (iOS only)
 
 Use it to restrict the distance from the edges of screen in which the gesture should be recognized. To be used alongside `fullScreenSwipeEnabled`. The responsive area is covered with 4 values: `start`, `end`, `top`, `bottom`. Example usage:
+IMPORTANT: Starting from iOS 26, this prop conflicts with the native behavior of full screen swipe to dismiss, therefore it is ignored.
 
 ```tsx
 gestureResponseDistance: {

ios/RNSScreen.mm

@@ -140,6 +140,18 @@ - (void)initCommonProps
 #endif // RCT_NEW_ARCH_ENABLED
 }
 
+- (BOOL)getFullScreenSwipeShadowEnabled
+{
+  if (@available(iOS 26, *)) {
+    // fullScreenSwipeShadow is tied to RNSPanGestureRecognizer, which, on iOS 26, is used only for custom animations,
+    // and replaced with native interactiveContentPopGestureRecognizer for everything else.
+    // We want them to look similar and native-like, so it should default to `YES`.
+    return YES;
+  }
+
+  return _fullScreenSwipeShadowEnabled;
+}
+
 - (UIViewController *)reactViewController
 {
   return _controller;
@@ -731,9 +743,27 @@ - (void)notifyTransitionProgress:(double)progress closing:(BOOL)closing goingFor
 #endif
 }
 
-#if !RCT_NEW_ARCH_ENABLED
+- (void)willMoveToWindow:(UIWindow *)newWindow
+{
+  if (@available(iOS 26, *)) {
+    // In iOS 26, as soon as another screen appears in transition, it is interactable
+    // To avoid glitches resulting from clicking buttons mid transition, we temporarily disable all interactions
+    // Disabling interactions for parent navigation controller won't be enough in case of nested stack
+    // Furthermore, a stack put inside a modal will exist in an entirely different hierarchy
+    // To be sure, we block interactions on the whole window.
+    // Note that newWindows is nil when moving from instead of moving to, and Obj-C handles nil correctly
+    newWindow.userInteractionEnabled = false;
+  }
+}
+
 - (void)presentationControllerWillDismiss:(UIPresentationController *)presentationController
 {
+  if (@available(iOS 26, *)) {
+    // Disable interactions to disallow multiple modals dismissed at once; see willMoveToWindow
+    presentationController.containerView.window.userInteractionEnabled = false;
+  }
+
+#if !RCT_NEW_ARCH_ENABLED
   // On Paper, we need to call both "cancel" and "reset" here because RN's gesture
   // recognizer does not handle the scenario when it gets cancelled by other top
   // level gesture recognizer. In this case by the modal dismiss gesture.
@@ -746,8 +776,8 @@ - (void)presentationControllerWillDismiss:(UIPresentationController *)presentati
   // down.
   [_touchHandler cancel];
   [_touchHandler reset];
-}
 #endif // !RCT_NEW_ARCH_ENABLED
+}
 
 - (BOOL)presentationControllerShouldDismiss:(UIPresentationController *)presentationController
 {
@@ -759,6 +789,11 @@ - (BOOL)presentationControllerShouldDismiss:(UIPresentationController *)presenta
 
 - (void)presentationControllerDidAttemptToDismiss:(UIPresentationController *)presentationController
 {
+  if (@available(iOS 26, *)) {
+    // Reenable interactions; see presentationControllerWillDismiss
+    presentationController.containerView.window.userInteractionEnabled = true;
+  }
+
   // NOTE(kkafar): We should consider depracating the use of gesture cancel here & align
   // with usePreventRemove API of react-navigation v7.
   [self notifyGestureCancel];
@@ -769,6 +804,12 @@ - (void)presentationControllerDidAttemptToDismiss:(UIPresentationController *)pr
 
 - (void)presentationControllerDidDismiss:(UIPresentationController *)presentationController
 {
+  if (@available(iOS 26, *)) {
+    // Reenable interactions; see presentationControllerWillDismiss
+    // Dismissed screen doesn't hold a reference to window, but presentingViewController.view does
+    presentationController.presentingViewController.view.window.userInteractionEnabled = true;
+  }
+
   if ([_reactSuperview respondsToSelector:@selector(presentationControllerDidDismiss:)]) {
     [_reactSuperview performSelector:@selector(presentationControllerDidDismiss:) withObject:presentationController];
   }
@@ -1529,6 +1570,10 @@ - (void)viewWillDisappear:(BOOL)animated
 
 - (void)viewDidAppear:(BOOL)animated
 {
+  if (@available(iOS 26, *)) {
+    // Reenable interactions, see willMoveToWindow
+    self.view.window.userInteractionEnabled = true;
+  }
   [super viewDidAppear:animated];
   if (!_isSwiping || _shouldNotify) {
     // we are going forward or dismissing without swipe