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The SwiftUI pager's collection view claimed every horizontal drag, so react-native-screens' full-screen back swipe (its own pan recognizer before iOS 26, interactiveContentPopGestureRecognizer on iOS 26) never won, even on the first page. Recognizing simultaneously does not help because UIKit still hands the touch to the scroll view, so the pan has to be refused before it begins. UIKit only asks the scroll view itself in gestureRecognizerShouldBegin, so the introspected collection view gets a runtime subclass, the same approach disableSafeArea() uses. The pan is refused only on page 0 of a horizontal pager, only in the back direction, and only while the nearest navigation controller can pop. iOS 26 also attaches UIScrollViewPagingSwipeGestureRecognizer to paging scroll views, which flips a page on a quick flick even when the pan never begins; it is refused under the same conditions. Fixes callstack#1050 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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🟡 Changes recommended
Arbitration misses iOS 15’s embedded paging scroller and suppresses overdrag when no eligible back gesture is available.
2 open issues
What changed in this PR
Updates the SwiftUI iOS pager to yield first-page back swipes to navigation, addressing #1050.
Changes:
- Tracks pager state for gesture arbitration.
- Adds runtime overrides for paging pans and iOS 26 paging-swipe recognizers.
| File | Description |
|---|---|
| ios/PagerView.swift | Attaches the observer and synchronizes pager state. |
| ios/PagerGestureObserver.swift | Implements direction-aware back-gesture arbitration. |
Review effort: Balanced
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Summary
The SwiftUI pager's collection view claimed every horizontal drag, so react-native-screens' full-screen back swipe (its own pan recognizer before iOS 26, interactiveContentPopGestureRecognizer on iOS 26) never won, even on the first page. Recognizing simultaneously does not help because UIKit still hands the touch to the scroll view, so the pan has to be refused before it begins. UIKit only asks the scroll view itself in gestureRecognizerShouldBegin, so the introspected collection view gets a runtime subclass, the same approach disableSafeArea() uses.
The pan is refused only on page 0 of a horizontal pager, only in the back direction, and only while the nearest navigation controller can pop. iOS 26 also attaches UIScrollViewPagingSwipeGestureRecognizer to paging scroll views, which flips a page on a quick flick even when the pan never begins; it is refused under the same conditions.
Fixes #1050
The implementation is based on @nickbvr comment #1050 (comment)
Test Plan
What's required for testing (prerequisites)?
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README.md