Problem

The AVCaptureVideoPreviewLayer connection orientation is never synced with the current device orientation. This causes the camera preview to appear rotated 90 degrees when the device is in landscape mode - most commonly observed on iPad, but affects any iOS device that supports multiple orientations.

Root Cause

In index.ios.ts, createNativeView() creates the AVCaptureVideoPreviewLayer from the capture session and adds it to the view, but never sets videoOrientation (or videoRotationAngle on iOS 17+) on the layer connection. The onLayout() method updates the layer frame but not its orientation.

Fix

Added a private _syncPreviewOrientation() method that:

1. Reads the current interface orientation from UIWindowScene.interfaceOrientation (the modern API, replacing the deprecated UIApplication.statusBarOrientation)
2. Maps the UIInterfaceOrientation value to the appropriate rotation angle
3. Applies the rotation via videoRotationAngle (iOS 17+) or falls back to the deprecated videoOrientation for older iOS versions
4. Uses setTimeout to defer the update, as the AVCaptureConnection may not be established immediately after startPreview()

The method is called:

• After startPreview() in onLoaded()
• On Application.orientationChanged events (listener registered in onLoaded(), removed in onUnloaded())
• After toggleCamera(), since switching cameras resets the session connection

Testing

Verified the fix corrects the 90-degree rotation on iPad in landscape mode when using MLKitView with DetectionType.Barcode via @nativescript/mlkit-barcode-scanning.

Made with Cursor