Fix bug CameraView on iOS: camera preview is not always rotated correct and photos are rotated (CommunityToolkit#2312)

* Fix bug CameraView on iOS: camera preview is not always rotated correct and photos are rotated

* Update src/CommunityToolkit.Maui.Camera/CameraManager.macios.cs

Co-authored-by: Shaun Lawrence <shaunrlawrence@gmail.com>

* Removed the null forgiving operator ! and added null checks. Removed TODO comment.

* Add exception message to the OnMediaCaptureFailed call

* Use `static` on iOS Devices

* Assign field `previewView`, Use pattern matching on `AVMediaTypes.Video.GetConstant()` , remove iOS 11 and iOS 13 checks since `CommunityToolkit.Maui.Camera` only supports iOS 15+

* Initialize `previewView` first

---------

Co-authored-by: Shaun Lawrence <shaunrlawrence@gmail.com>
Co-authored-by: James Crutchley <ne0rmatrix@gmail.com>
Co-authored-by: Brandon Minnick <13558917+brminnick@users.noreply.github.com>

Author: 4 people

samples/CommunityToolkit.Maui.Sample/CommunityToolkit.Maui.Sample.csproj

@@ -101,7 +101,7 @@
 
   <!-- Fixes Static Registrar causing Linker error: https://github.com/xamarin/xamarin-macios/blob/main/docs/managed-static-registrar.md -->
   <Target Name="SelectStaticRegistrar" AfterTargets="SelectRegistrar">
-    <PropertyGroup Condition="'$(Registrar)' == 'managed-static' and $([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))=='maccatalyst'">
+    <PropertyGroup Condition="'$(Registrar)' == 'managed-static'">
         <Registrar>static</Registrar>
     </PropertyGroup>
   </Target>

src/CommunityToolkit.Maui.Camera/CameraManager.macios.cs

@@ -1,6 +1,4 @@
-using System.Buffers;
-using System.Diagnostics;
-using System.Runtime.InteropServices;
+using System.Diagnostics;
 using AVFoundation;
 using CommunityToolkit.Maui.Core.Primitives;
 using CommunityToolkit.Maui.Extensions;
@@ -22,19 +20,26 @@ partial class CameraManager
 
 	AVCaptureFlashMode flashMode;
 
+	IDisposable? orientationDidChangeObserver;
+	PreviewView? previewView;
+	AVCaptureVideoOrientation videoOrientation;
+
 	// IN the future change the return type to be an alias
 	public UIView CreatePlatformView()
 	{
 		captureSession = new AVCaptureSession
 		{
 			SessionPreset = AVCaptureSession.PresetPhoto
 		};
-
-		var previewView = new PreviewView
+		
+		previewView = new PreviewView
 		{
 			Session = captureSession
 		};
 
+		orientationDidChangeObserver = UIDevice.Notifications.ObserveOrientationDidChange((_, _) => UpdateVideoOrientation());
+		UpdateVideoOrientation();
+
 		return previewView;
 	}
 
@@ -194,41 +199,51 @@ protected virtual async partial ValueTask PlatformTakePicture(CancellationToken
 		var capturePhotoSettings = AVCapturePhotoSettings.FromFormat(codecSettings);
 		capturePhotoSettings.FlashMode = photoOutput.SupportedFlashModes.Contains(flashMode) ? flashMode : photoOutput.SupportedFlashModes.First();
 
+		if (AVMediaTypes.Video.GetConstant() is NSString avMediaTypeVideo)
+		{
+			var photoOutputConnection = photoOutput.ConnectionFromMediaType(avMediaTypeVideo);
+			if (photoOutputConnection is not null)
+			{
+				photoOutputConnection.VideoOrientation = videoOrientation;
+			}
+		}
+
 		var wrapper = new AVCapturePhotoCaptureDelegateWrapper();
 
 		photoOutput.CapturePhoto(capturePhotoSettings, wrapper);
 
 		var result = await wrapper.Task.WaitAsync(token);
-		var data = result.Photo.FileDataRepresentation;
-
 		if (result.Error is not null)
 		{
-			cameraView.OnMediaCapturedFailed(result.Error.LocalizedFailureReason);
-			return;
-		}
+			var failureReason = result.Error.LocalizedDescription;
+			if (!string.IsNullOrEmpty(result.Error.LocalizedFailureReason))
+			{
+				failureReason = $"{failureReason} - {result.Error.LocalizedFailureReason}";
+			}
 
-		if (data is null)
-		{
-			cameraView.OnMediaCapturedFailed("Unable to retrieve the file data representation from the captured result.");
+			cameraView.OnMediaCapturedFailed(failureReason);
 			return;
 		}
 
-		var dataBytes = ArrayPool<byte>.Shared.Rent((int)data.Length);
-
+		Stream? imageData;
 		try
 		{
-			Marshal.Copy(data.Bytes, dataBytes, 0, (int)data.Length);
-
-			cameraView.OnMediaCaptured(new MemoryStream(dataBytes));
+			imageData = result.Photo.FileDataRepresentation?.AsStream();
+		}
+		catch (Exception e)
+		{
+			// possible exception: ObjCException NSInvalidArgumentException NSAllocateMemoryPages(...) failed in AVCapturePhoto.get_FileDataRepresentation()
+			cameraView.OnMediaCapturedFailed($"Unable to retrieve the file data representation from the captured result: {e.Message}");
+			return;
 		}
-		catch (Exception ex)
+
+		if (imageData is null)
 		{
-			cameraView.OnMediaCapturedFailed(ex.Message);
-			throw;
+			cameraView.OnMediaCapturedFailed("Unable to retrieve the file data representation from the captured result.");
 		}
-		finally
+		else
 		{
-			ArrayPool<byte>.Shared.Return(dataBytes);
+			cameraView.OnMediaCaptured(imageData);
 		}
 	}
 
@@ -243,11 +258,37 @@ protected virtual void Dispose(bool disposing)
 			captureInput?.Dispose();
 			captureInput = null;
 
+			orientationDidChangeObserver?.Dispose();
+			orientationDidChangeObserver = null;
+
 			photoOutput?.Dispose();
 			photoOutput = null;
 		}
 	}
 
+	static AVCaptureVideoOrientation GetVideoOrientation()
+	{
+		IEnumerable<UIScene> scenes = UIApplication.SharedApplication.ConnectedScenes;
+		var interfaceOrientation = scenes.FirstOrDefault() is UIWindowScene windowScene 
+			? windowScene.InterfaceOrientation 
+			: UIApplication.SharedApplication.StatusBarOrientation;
+
+		return interfaceOrientation switch
+		{
+			UIInterfaceOrientation.Portrait => AVCaptureVideoOrientation.Portrait,
+			UIInterfaceOrientation.PortraitUpsideDown => AVCaptureVideoOrientation.PortraitUpsideDown,
+			UIInterfaceOrientation.LandscapeRight => AVCaptureVideoOrientation.LandscapeRight,
+			UIInterfaceOrientation.LandscapeLeft => AVCaptureVideoOrientation.LandscapeLeft,
+			_ => AVCaptureVideoOrientation.Portrait
+		};
+	}
+
+	void UpdateVideoOrientation()
+	{
+		videoOrientation = GetVideoOrientation();
+		previewView?.UpdatePreviewVideoOrientation(videoOrientation);
+	}
+
 	sealed class AVCapturePhotoCaptureDelegateWrapper : AVCapturePhotoCaptureDelegate
 	{
 		readonly TaskCompletionSource<CapturePhotoResult> taskCompletionSource = new();
@@ -299,20 +340,15 @@ public AVCaptureSession? Session
 		public override void LayoutSubviews()
 		{
 			base.LayoutSubviews();
+			UpdatePreviewVideoOrientation(GetVideoOrientation());
+		}
 
-			if (PreviewLayer.Connection is null)
+		public void UpdatePreviewVideoOrientation(AVCaptureVideoOrientation videoOrientation)
+		{
+			if (PreviewLayer.Connection is not null)
 			{
-				return;
+				PreviewLayer.Connection.VideoOrientation = videoOrientation;
 			}
-
-			PreviewLayer.Connection.VideoOrientation = UIDevice.CurrentDevice.Orientation switch
-			{
-				UIDeviceOrientation.Portrait => AVCaptureVideoOrientation.Portrait,
-				UIDeviceOrientation.PortraitUpsideDown => AVCaptureVideoOrientation.PortraitUpsideDown,
-				UIDeviceOrientation.LandscapeLeft => AVCaptureVideoOrientation.LandscapeRight,
-				UIDeviceOrientation.LandscapeRight => AVCaptureVideoOrientation.LandscapeLeft,
-				_ => PreviewLayer.Connection.VideoOrientation
-			};
 		}
 	}
 }