Fix bsky logo appearing during screen back transition

2026-08-27 13:44:46 +02:00
parent 8e52eba582
commit 96003ff3c0
3 changed files with 153 additions and 12 deletions
@@ -31,3 +31,112 @@ index 76bb694854b29d7f779f38244cd48113b429ea1f..fd402ac938862e8d39c5467c1b5c86c4
                     startTransitionRecursive(child)
                 }
             }
+diff --git a/ios/RNSScreen.mm b/ios/RNSScreen.mm
+index 9b66012dc8db1e3af0cb5457f8dad86e7f2fe5e3..a7f1f613c291de8421f6f117c06d35ba34a2d908 100644
+--- a/ios/RNSScreen.mm
+++ b/ios/RNSScreen.mm
+@@ -1,4 +1,5 @@
+ #import <UIKit/UIKit.h>
+#import <objc/runtime.h>
+ 
+ #import "RNSModalScreen.h"
+ #import "RNSScreen.h"
+@@ -1180,9 +1181,82 @@ - (BOOL)hasHeaderConfig
+   return _config != nil;
+ }
+ 
+/*
+ * PATCH (secure-snapshot): content protected by an isSecureTextEntry canvas
+ * (per-view capture protection, e.g. expo-privacy-sensitive) is stripped from
+ * the render-server snapshot RNSScreen takes for JS-driven pops, so the user
+ * sees the hidden fallback (the GrowthHack butterfly) during the transition.
+ * The capture-exclusion flag is only consulted for layers INSIDE a captured
+ * subtree, so a snapshot rooted BELOW the flagged canvas still includes the
+ * content.
+ *
+ * By the time setViewToSnapshot runs, the screen's children are already
+ * unmounted (only the pixels survive on the render server), so the secure
+ * subtrees must be captured HERE - before the transaction's mutations apply,
+ * while the subtree is intact. The overlays are stashed on the screen view
+ * and composited over the main snapshot in setViewToSnapshot, each re-wrapped
+ * in a fresh secure canvas so real captures (screenshots/recordings) taken
+ * during the transition still exclude them.
+ */
+static void RNSCollectPrivacySensitiveViews(UIView *view, NSMutableArray<UIView *> *out)
+{
+  // Swift classes are namespaced in the ObjC runtime ("Module.ClassName")
+  if ([NSStringFromClass([view class]) hasSuffix:@"ExpoPrivacySensitiveView"]) {
+    [out addObject:view];
+    return;
+  }
+  for (UIView *subview in view.subviews) {
+    RNSCollectPrivacySensitiveViews(subview, out);
+  }
+}
+
+static UIView *_Nullable RNSMakeSecureCanvas(void)
+{
+  UITextField *field = [UITextField new];
+  field.secureTextEntry = YES;
+  field.userInteractionEnabled = NO;
+  UIView *canvas = (UIView *)field.layer.sublayers.firstObject.delegate;
+  if (![canvas isKindOfClass:[UIView class]]) {
+    return nil;
+  }
+  canvas.clipsToBounds = NO;
+  canvas.backgroundColor = UIColor.clearColor;
+  // retain the field alongside the canvas in case the capture exclusion ever
+  // depends on the owning field staying alive
+  objc_setAssociatedObject(canvas, "RNSSecureCanvasField", field, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
+  return canvas;
+}
+
+static char RNSSecureOverlaysKey;
+
+ - (void)willBeUnmountedInUpcomingTransaction
+ {
+   _markedForUnmountInCurrentTransaction = YES;
+
+  NSMutableArray<UIView *> *sensitiveViews = [NSMutableArray new];
+  RNSCollectPrivacySensitiveViews(self, sensitiveViews);
+  NSMutableArray<UIView *> *overlays = [NSMutableArray new];
+  for (UIView *sensitiveView in sensitiveViews) {
+    UIView *canvas = sensitiveView.subviews.firstObject;
+    for (UIView *content in canvas.subviews) {
+      UIView *pieceSnapshot = [content snapshotViewAfterScreenUpdates:NO];
+      if (pieceSnapshot == nil) {
+        continue;
+      }
+      CGRect frameInScreen = [content convertRect:content.bounds toView:self];
+      UIView *secureWrap = RNSMakeSecureCanvas();
+      if (secureWrap != nil) {
+        secureWrap.frame = frameInScreen;
+        pieceSnapshot.frame = secureWrap.bounds;
+        [secureWrap addSubview:pieceSnapshot];
+        [overlays addObject:secureWrap];
+      } else {
+        pieceSnapshot.frame = frameInScreen;
+        [overlays addObject:pieceSnapshot];
+      }
+    }
+  }
+  objc_setAssociatedObject(self, &RNSSecureOverlaysKey, overlays.count > 0 ? overlays : nil, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
+ }
+ 
+ + (react::ComponentDescriptorProvider)componentDescriptorProvider
+@@ -1999,6 +2073,15 @@ - (void)setViewToSnapshot
+     auto afterUpdates = self.screenView.snapshotAfterUpdates;
+     UIView *snapshot = [self.view snapshotViewAfterScreenUpdates:afterUpdates];
+     snapshot.frame = self.view.frame;
+
+    // PATCH (secure-snapshot): composite the secure-content overlays captured
+    // in willBeUnmountedInUpcomingTransaction (see comment there)
+    NSArray<UIView *> *overlays = objc_getAssociatedObject(self.screenView, &RNSSecureOverlaysKey);
+    for (UIView *overlay in overlays) {
+      [snapshot addSubview:overlay];
+    }
+    objc_setAssociatedObject(self.screenView, &RNSSecureOverlaysKey, nil, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
+
+     [self.view removeFromSuperview];
+     self.view = snapshot;
+     [superView addSubview:snapshot];