fix(ios): keep a hidden navigation bar hidden on iOS 15

ios/PagerViewIOS15NavigationBarCompat.swift

@@ -0,0 +1,65 @@
+import SwiftUI
+import UIKit
+
+/// Workaround for SwiftUI re-showing an intentionally hidden `UINavigationBar` on iOS 15.
+///
+/// On iOS 15 `UIHostingController` installs SwiftUI's `UIKitNavigationBarBridge`, which calls
+/// `-[UINavigationController setNavigationBarHidden:NO]` on the enclosing navigation controller
+/// whenever the hosting view appears. When that bar is deliberately hidden — for example the
+/// `RNSContainerNavigationController` that `react-native-screens` creates for `hasTwoStates`
+/// tab/drawer containers — the bridge re-shows an empty `UINavigationBar` that then swallows
+/// touches meant for the React Native views underneath (in this case the JS header buttons).
+///
+/// On iOS 16 and later SwiftUI no longer re-shows the bar, so a plain `UIHostingController` is
+/// returned and none of the code below runs.
+///
+/// - Note: Delete this file together with the single `PagerViewIOS15NavigationBarCompat` call in
+///   `PagerViewProvider.swift` once the minimum supported iOS version is 16.
+enum PagerViewIOS15NavigationBarCompat {
+  /// Returns a hosting controller that keeps the enclosing navigation bar's hidden state across
+  /// the appearance callbacks on iOS 15, and a plain `UIHostingController` on iOS 16+.
+  static func makeHostingController<Content: View>(
+    rootView: Content,
+    ignoreSafeArea: Bool
+  ) -> UIHostingController<Content> {
+    if #available(iOS 16, *) {
+      return UIHostingController(rootView: rootView, ignoreSafeArea: ignoreSafeArea)
+    }
+
+    let hostingController = PreservingNavigationBarHostingController(rootView: rootView)
+    if ignoreSafeArea {
+      hostingController.disableSafeArea()
+    }
+
+    return hostingController
+  }
+}
+
+/// `UIHostingController` that restores the enclosing navigation bar's hidden state around
+/// `viewWillAppear`, see `PagerViewIOS15NavigationBarCompat`.
+private final class PreservingNavigationBarHostingController<Content: View>: UIHostingController<Content> {
+  override func viewWillAppear(_ animated: Bool) {
+    let navigationController = enclosingNavigationController
+    let wasNavigationBarHidden = navigationController?.isNavigationBarHidden == true
+    super.viewWillAppear(animated)
+    if wasNavigationBarHidden {
+      navigationController?.setNavigationBarHidden(true, animated: false)
+    }
+  }
+
+  private var enclosingNavigationController: UINavigationController? {
+    if let navigationController {
+      return navigationController
+    }
+
+    var viewController: UIViewController? = self
+    while let current = viewController {
+      if let navigationController = current as? UINavigationController {
+        return navigationController
+      }
+      viewController = current.parent
+    }
+
+    return nil
+  }
+}

ios/PagerViewProvider.swift

@@ -236,7 +236,9 @@ import UIKit
     // has them at full size. `PageChildViewController` reads *this* view's
     // insets (the RN screen's, including a native search bar) and re-injects
     // them; the two are independent.
-    let hostingController = UIHostingController(
+    // iOS 15 only, see PagerViewIOS15NavigationBarCompat.swift
+    // (delete together with the iOS 15 support).
+    let hostingController = PagerViewIOS15NavigationBarCompat.makeHostingController(
       rootView: PagerView(props: props, delegate: delegate),
       ignoreSafeArea: true
     )