Add a failure reason to the MediaCaptureFailedEventArgs (#2085)

* Add a failure reason to the MediaCaptureFailedEventArgs

* Update Unit Test to validate error message

---------

Co-authored-by: Shaun Lawrence <17139988+bijington@users.noreply.github.com>
Co-authored-by: Brandon Minnick <13558917+brminnick@users.noreply.github.com>

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

@@ -276,13 +276,15 @@ public override void OnCaptureSuccess(IImageProxy image)
 
 			if (img is null)
 			{
+				cameraView.OnMediaCapturedFailed("Unable to obtain Image data.");
 				return;
 			}
 
 			var buffer = GetFirstPlane(img.GetPlanes())?.Buffer;
 
 			if (buffer is null)
 			{
+				cameraView.OnMediaCapturedFailed("Unable to obtain a buffer for the image plane.");
 				image.Close();
 				return;
 			}
@@ -294,6 +296,11 @@ public override void OnCaptureSuccess(IImageProxy image)
 				var memStream = new MemoryStream(imgData);
 				cameraView.OnMediaCaptured(memStream);
 			}
+			catch (System.Exception ex)
+			{
+				cameraView.OnMediaCapturedFailed(ex.Message);
+				throw;
+			}
 			finally
 			{
 				image.Close();
@@ -313,7 +320,7 @@ public override void OnCaptureSuccess(IImageProxy image)
 		public override void OnError(ImageCaptureException exception)
 		{
 			base.OnError(exception);
-			cameraView.OnMediaCapturedFailed();
+			cameraView.OnMediaCapturedFailed(exception.Message ?? "An unknown error occurred.");
 		}
 	}
 

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

@@ -199,10 +199,15 @@ protected virtual async partial ValueTask PlatformTakePicture(CancellationToken
 		var result = await wrapper.Task.WaitAsync(token);
 		var data = result.Photo.FileDataRepresentation;
 
+		if (result.Error is not null)
+		{
+			cameraView.OnMediaCapturedFailed(result.Error.LocalizedFailureReason);
+			return;
+		}
+
 		if (data is null)
 		{
-			// TODO: Pass NSError information
-			cameraView.OnMediaCapturedFailed();
+			cameraView.OnMediaCapturedFailed("Unable to retrieve the file data representation from the captured result.");
 			return;
 		}
 
@@ -214,6 +219,11 @@ protected virtual async partial ValueTask PlatformTakePicture(CancellationToken
 
 			cameraView.OnMediaCaptured(new MemoryStream(dataBytes));
 		}
+		catch (Exception ex)
+		{
+			cameraView.OnMediaCapturedFailed(ex.Message);
+			throw;
+		}
 		finally
 		{
 			ArrayPool<byte>.Shared.Return(dataBytes);

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

@@ -95,11 +95,19 @@ protected virtual async partial ValueTask PlatformTakePicture(CancellationToken
 
 		MemoryStream memoryStream = new();
 
-		await mediaCapture.CapturePhotoToStreamAsync(ImageEncodingProperties.CreateJpeg(), memoryStream.AsRandomAccessStream());
+		try
+		{
+			await mediaCapture.CapturePhotoToStreamAsync(ImageEncodingProperties.CreateJpeg(), memoryStream.AsRandomAccessStream());
 
-		memoryStream.Position = 0;
+			memoryStream.Position = 0;
 
-		cameraView.OnMediaCaptured(memoryStream);
+			cameraView.OnMediaCaptured(memoryStream);
+		}
+		catch (Exception ex)
+		{
+			cameraView.OnMediaCapturedFailed(ex.Message);
+			throw;
+		}
 	}
 
 	protected virtual void Dispose(bool disposing)

src/CommunityToolkit.Maui.Camera/Interfaces/ICameraView.shared.cs

@@ -60,7 +60,8 @@ public interface ICameraView : IView, IAsynchronousHandler
 	/// <summary>
 	/// Occurs when an image capture fails.
 	/// </summary>
-	void OnMediaCapturedFailed();
+	/// <param name="failureReason">A string containing the reason why the capture attempt failed.</param>
+	void OnMediaCapturedFailed(string failureReason);
 
 	/// <summary>
 	/// Triggers the camera to capture an image.

src/CommunityToolkit.Maui.Camera/Primitives/MediaCaptureFailedEventArgs.shared.cs

@@ -5,4 +5,17 @@
 /// </summary>
 public class MediaCaptureFailedEventArgs : EventArgs
 {
+	/// <summary>
+	/// Creates a new instance of <see cref="MediaCaptureFailedEventArgs"/>.
+	/// </summary>
+	/// <param name="failureReason">A string containing the reason why the capture attempt failed.</param>
+	public MediaCaptureFailedEventArgs(string failureReason)
+	{
+		FailureReason = failureReason;
+	}
+
+	/// <summary>
+	/// Gets the reason why the capture attempt failed.
+	/// </summary>
+	public string FailureReason { get; } 
 }

src/CommunityToolkit.Maui.Camera/Views/CameraView.shared.cs

@@ -201,9 +201,9 @@ public void OnMediaCaptured(Stream imageData)
 	}
 
 	/// <inheritdoc cref="ICameraView.OnMediaCapturedFailed"/>
-	public void OnMediaCapturedFailed()
+	public void OnMediaCapturedFailed(string failureReason)
 	{
-		weakEventManager.HandleEvent(this, new MediaCaptureFailedEventArgs(), nameof(MediaCaptureFailed));
+		weakEventManager.HandleEvent(this, new MediaCaptureFailedEventArgs(failureReason), nameof(MediaCaptureFailed));
 	}
 
 	/// <inheritdoc cref="ICameraView.GetAvailableCameras"/>

src/CommunityToolkit.Maui.UnitTests/Views/CameraView/CameraViewTests.cs

@@ -61,14 +61,27 @@ public void OnMediaCaptured_RaisesMediaCapturedEvent()
 		Assert.True(eventRaised);
 	}
 
-	[Fact]
-	public void OnMediaCapturedFailed_RaisesMediaCaptureFailedEvent()
+	[Fact(Timeout = (int)TestDuration.Short)]
+	public async Task OnMediaCapturedFailed_RaisesMediaCaptureFailedEvent()
 	{
-		bool eventRaised = false;
-		cameraView.MediaCaptureFailed += (sender, args) => eventRaised = true;
+		const string failureMessage = "Proof that this test passes";
+
+		bool wasEventRaised = false;
+		var mediaCaptureFailedTcs = new TaskCompletionSource<MediaCaptureFailedEventArgs>();
+		cameraView.MediaCaptureFailed += HandleMediaCaptureFailed;
 
-		cameraView.OnMediaCapturedFailed();
+		cameraView.OnMediaCapturedFailed(failureMessage);
 
-		Assert.True(eventRaised);
+		var mediaCaptureFailedEventArgs = await mediaCaptureFailedTcs.Task;
+
+		Assert.True(wasEventRaised);
+		Assert.Equal(failureMessage, mediaCaptureFailedEventArgs.FailureReason);
+
+		void HandleMediaCaptureFailed(object? sender, MediaCaptureFailedEventArgs e)
+		{
+			cameraView.MediaCaptureFailed -= HandleMediaCaptureFailed;
+			wasEventRaised = true;
+			mediaCaptureFailedTcs.SetResult(e);
+		}
 	}
 }