Refactor CameraView.CaptureImage, CameraView.StartCameraPreview and CameraView.StopCameraPreview (#2655)

TheCodeTraveler · Copilot · ne0rrmatrix · web-flow · commit f26b899d1d72 · 2025-06-05T13:45:27.000-07:00
* Remove `CommunityToolkit.Maui.Core.Primitives` namespace

* Properly await Tasks

* Remove unused namespaces

* Remove `IAsynchronousHandler`

* Update CameraViewHandler.shared.cs

* Update CameraViewHandler.shared.cs

* Remove unnecessary null checks

* Fix Sample App Compiler Error

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

Co-authored-by: Copilot &lt;175728472+Copilot@users.noreply.github.com&gt;

* Refactor StopCameraPreview

* Refactor `ICameraView`

* Update Unit Tests

* Remove invalid XML comment

* Update CameraManager.tizen.cs

* `dotnet format`

* Revert `StopCameraPreview.StopCameraPreview`

* Update CameraViewDefaults.shared.cs

---------

Co-authored-by: Brandon Minnick &lt;13558917+brminnick@users.noreply.github.com&gt;
Co-authored-by: Copilot &lt;175728472+Copilot@users.noreply.github.com&gt;
Co-authored-by: James Crutchley &lt;ne0rmatrix@gmail.com&gt;
diff --git a/samples/CommunityToolkit.Maui.Sample/Pages/Views/CameraView/CameraViewPage.xaml.cs b/samples/CommunityToolkit.Maui.Sample/Pages/Views/CameraView/CameraViewPage.xaml.cs
@@ -1,6 +1,6 @@
 using System.Diagnostics;
+using CommunityToolkit.Maui.Core;
 using CommunityToolkit.Maui.Sample.ViewModels.Views;
-using CommunityToolkit.Maui.Views;
 
 namespace CommunityToolkit.Maui.Sample.Pages.Views;
 
diff --git a/src/CommunityToolkit.Maui.Camera/CameraInfo.shared.cs b/src/CommunityToolkit.Maui.Camera/CameraInfo.shared.cs
@@ -1,5 +1,4 @@
 ﻿using System.Text;
-using CommunityToolkit.Maui.Core.Primitives;
 
 #if IOS || MACCATALYST
 using AVFoundation;
diff --git a/src/CommunityToolkit.Maui.Camera/CameraManager.android.cs b/src/CommunityToolkit.Maui.Camera/CameraManager.android.cs
@@ -7,7 +7,6 @@
 using AndroidX.Camera.Lifecycle;
 using AndroidX.Core.Content;
 using AndroidX.Lifecycle;
-using CommunityToolkit.Maui.Core.Primitives;
 using CommunityToolkit.Maui.Extensions;
 using Java.Lang;
 using Java.Util.Concurrent;
diff --git a/src/CommunityToolkit.Maui.Camera/CameraManager.macios.cs b/src/CommunityToolkit.Maui.Camera/CameraManager.macios.cs
@@ -1,6 +1,5 @@
 ﻿using System.Diagnostics;
 using AVFoundation;
-using CommunityToolkit.Maui.Core.Primitives;
 using CommunityToolkit.Maui.Extensions;
 using CoreMedia;
 using Foundation;
diff --git a/src/CommunityToolkit.Maui.Camera/CameraManager.net.cs b/src/CommunityToolkit.Maui.Camera/CameraManager.net.cs
@@ -1,5 +1,3 @@
-using CommunityToolkit.Maui.Core.Primitives;
-
 namespace CommunityToolkit.Maui.Core;
 
 partial class CameraManager
diff --git a/src/CommunityToolkit.Maui.Camera/CameraManager.shared.cs b/src/CommunityToolkit.Maui.Camera/CameraManager.shared.cs
@@ -1,6 +1,4 @@
-﻿using CommunityToolkit.Maui.Core.Primitives;
-
-namespace CommunityToolkit.Maui.Core;
+﻿namespace CommunityToolkit.Maui.Core;
 
 /// <summary>
 /// A class that manages the camera functionality.
diff --git a/src/CommunityToolkit.Maui.Camera/CameraManager.tizen.cs b/src/CommunityToolkit.Maui.Camera/CameraManager.tizen.cs
@@ -1,5 +1,3 @@
-using CommunityToolkit.Maui.Core.Primitives;
-
 namespace CommunityToolkit.Maui.Core;
 
 partial class CameraManager
diff --git a/src/CommunityToolkit.Maui.Camera/CameraManager.windows.cs b/src/CommunityToolkit.Maui.Camera/CameraManager.windows.cs
@@ -1,7 +1,5 @@
 ﻿using System.Runtime.Versioning;
-using CommunityToolkit.Maui.Core.Primitives;
 using CommunityToolkit.Maui.Extensions;
-using Microsoft.Maui.Controls.PlatformConfiguration;
 using Microsoft.UI.Xaml.Controls;
 using Windows.Media.Capture;
 using Windows.Media.Capture.Frames;
diff --git a/src/CommunityToolkit.Maui.Camera/Extensions/CameraViewExtensions.android.cs b/src/CommunityToolkit.Maui.Camera/Extensions/CameraViewExtensions.android.cs
@@ -2,7 +2,6 @@
 using Android.Content.PM;
 using AndroidX.Camera.Core;
 using CommunityToolkit.Maui.Core;
-using CommunityToolkit.Maui.Core.Primitives;
 
 namespace CommunityToolkit.Maui.Extensions;
 
diff --git a/src/CommunityToolkit.Maui.Camera/Extensions/CameraViewExtensions.macios.cs b/src/CommunityToolkit.Maui.Camera/Extensions/CameraViewExtensions.macios.cs
@@ -1,6 +1,5 @@
 ﻿using AVFoundation;
 using CommunityToolkit.Maui.Core;
-using CommunityToolkit.Maui.Core.Primitives;
 
 namespace CommunityToolkit.Maui.Extensions;
 
diff --git a/src/CommunityToolkit.Maui.Camera/Handlers/CameraViewHandler.shared.cs b/src/CommunityToolkit.Maui.Camera/Handlers/CameraViewHandler.shared.cs
@@ -29,12 +29,7 @@ public partial class CameraViewHandler : ViewHandler<ICameraView, NativePlatform
 	/// The currently defined mappings between commands on the <see cref="ICameraView"/> and
 	/// commands on the <see cref="NativePlatformCameraPreviewView"/>. 
 	/// </summary>
-	public static CommandMapper<ICameraView, CameraViewHandler> CommandMapper = new(ViewCommandMapper)
-	{
-		[nameof(ICameraView.CaptureImage)] = MapCaptureImage,
-		[nameof(ICameraView.StartCameraPreview)] = MapStartCameraPreview,
-		[nameof(ICameraView.StopCameraPreview)] = MapStopCameraPreview
-	};
+	public static CommandMapper<ICameraView, CameraViewHandler> CommandMapper = new(ViewCommandMapper);
 
 	readonly ICameraProvider cameraProvider = IPlatformApplication.Current?.Services.GetRequiredService<ICameraProvider>() ?? throw new CameraException($"{nameof(CameraProvider)} not found");
 
@@ -66,6 +61,9 @@ public void Dispose()
 		GC.SuppressFinalize(this);
 	}
 
+	internal CameraManager CameraManager => cameraManager
+		?? throw new InvalidOperationException($"{nameof(CameraManager)} cannot be used until the native view has been created");
+
 	/// <summary>
 	/// Creates a platform-specific view that will be rendered on that platform.
 	/// </summary>
@@ -74,7 +72,7 @@ protected override NativePlatformCameraPreviewView CreatePlatformView()
 		ArgumentNullException.ThrowIfNull(MauiContext);
 		cameraManager = new(MauiContext, VirtualView, cameraProvider, () => Init(VirtualView));
 
-		return (NativePlatformCameraPreviewView)cameraManager.CreatePlatformView();
+		return (NativePlatformCameraPreviewView)CameraManager.CreatePlatformView();
 
 		// When camera is loaded(switched), map the current flash mode to the platform view,
 		// reset the zoom factor to 1
@@ -90,8 +88,8 @@ protected override async void ConnectHandler(NativePlatformCameraPreviewView pla
 	{
 		base.ConnectHandler(platformView);
 
-		await (cameraManager?.ArePermissionsGranted() ?? Task.CompletedTask);
-		await (cameraManager?.ConnectCamera(CancellationToken.None) ?? Task.CompletedTask);
+		await CameraManager.ArePermissionsGranted();
+		await CameraManager.ConnectCamera(CancellationToken.None);
 		await cameraProvider.RefreshAvailableCameras(CancellationToken.None);
 	}
 
@@ -121,55 +119,38 @@ static async void MapIsAvailable(CameraViewHandler handler, ICameraView view)
 	static void MapIsAvailable(CameraViewHandler handler, ICameraView view)
 #endif
 	{
-		var cameraAvailability = (ICameraView)handler.VirtualView;
+		var cameraView = (ICameraView)handler.VirtualView;
 
 #if ANDROID
-		cameraAvailability.UpdateAvailability(handler.Context);
+		cameraView.UpdateAvailability(handler.Context);
 #elif WINDOWS
-		await cameraAvailability.UpdateAvailability(CancellationToken.None);
+		await cameraView.UpdateAvailability(CancellationToken.None);
 #elif IOS || MACCATALYST
-		cameraAvailability.UpdateAvailability();
+		cameraView.UpdateAvailability();
 #elif TIZEN
 		throw new NotSupportedException("Tizen is not yet supported");
 #elif NET
 		throw new NotSupportedException("A specific platform is required, eg net-ios, net-android, net-maccatalyst, net-windows");
 #endif
 	}
 
-	static async void MapCaptureImage(CameraViewHandler handler, ICameraView view, object? arg3)
-	{
-		await (handler.cameraManager?.TakePicture(CancellationToken.None) ?? ValueTask.CompletedTask);
-		view.HandlerCompleteTCS.SetResult();
-	}
-
-	static async void MapStartCameraPreview(CameraViewHandler handler, ICameraView view, object? arg3)
-	{
-		await (handler.cameraManager?.StartCameraPreview(CancellationToken.None) ?? Task.CompletedTask);
-		view.HandlerCompleteTCS.SetResult();
-	}
-
 	static async void MapImageCaptureResolution(CameraViewHandler handler, ICameraView view)
 	{
-		await (handler.cameraManager?.UpdateCaptureResolution(view.ImageCaptureResolution, CancellationToken.None) ?? ValueTask.CompletedTask);
+		await handler.CameraManager.UpdateCaptureResolution(view.ImageCaptureResolution, CancellationToken.None);
 	}
 
 	static async void MapSelectedCamera(CameraViewHandler handler, ICameraView view)
 	{
-		await (handler.cameraManager?.UpdateCurrentCamera(view.SelectedCamera, CancellationToken.None) ?? ValueTask.CompletedTask);
-	}
-
-	static void MapStopCameraPreview(CameraViewHandler handler, ICameraView view, object? arg3)
-	{
-		handler.cameraManager?.StopCameraPreview();
+		await handler.CameraManager.UpdateCurrentCamera(view.SelectedCamera, CancellationToken.None);
 	}
 
 	static void MapCameraFlashMode(CameraViewHandler handler, ICameraView view)
 	{
-		handler.cameraManager?.UpdateFlashMode(view.CameraFlashMode);
+		handler.CameraManager.UpdateFlashMode(view.CameraFlashMode);
 	}
 
 	static void MapZoomFactor(CameraViewHandler handler, ICameraView view)
 	{
-		handler.cameraManager?.UpdateZoom(view.ZoomFactor);
+		handler.CameraManager.UpdateZoom(view.ZoomFactor);
 	}
 }
diff --git a/src/CommunityToolkit.Maui.Camera/Interfaces/IAsynchronouseHandler.cs b/src/CommunityToolkit.Maui.Camera/Interfaces/IAsynchronouseHandler.cs
diff --git a/src/CommunityToolkit.Maui.Camera/Interfaces/ICameraView.shared.cs b/src/CommunityToolkit.Maui.Camera/Interfaces/ICameraView.shared.cs
@@ -1,12 +1,9 @@
-﻿using CommunityToolkit.Maui.Camera;
-using CommunityToolkit.Maui.Core.Primitives;
-
-namespace CommunityToolkit.Maui.Core;
+﻿namespace CommunityToolkit.Maui.Core;
 
 /// <summary>
 /// Represents a visual element that provides the ability to show a camera preview and capture images.
 /// </summary>
-public interface ICameraView : IView, IAsynchronousHandler
+public interface ICameraView : IView
 {
 	/// <summary>
 	/// Gets the <see cref="CameraFlashMode"/>.
@@ -51,18 +48,6 @@ public interface ICameraView : IView, IAsynchronousHandler
 	/// </summary>
 	bool IsBusy { get; internal set; }
 
-	/// <summary>
-	/// Occurs when an image is captured by the camera.
-	/// </summary>
-	/// <param name="imageData">The image data held within a <see cref="Stream"/>.</param>
-	void OnMediaCaptured(Stream imageData);
-
-	/// <summary>
-	/// Occurs when an image capture fails.
-	/// </summary>
-	/// <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.
 	/// </summary>
@@ -79,7 +64,7 @@ public interface ICameraView : IView, IAsynchronousHandler
 	/// To customize the behavior of starting the camera preview, consider overriding the behavior through
 	/// <c>CameraViewHandler.CommandMapper.ReplaceMapping(nameof(ICameraView.StartCameraPreview), ADD YOUR METHOD);</c>.
 	/// </remarks>
-	ValueTask StartCameraPreview(CancellationToken token);
+	Task StartCameraPreview(CancellationToken token);
 
 	/// <summary>
 	/// Stops the camera preview.
@@ -96,4 +81,16 @@ public interface ICameraView : IView, IAsynchronousHandler
 	/// <param name="token"></param>
 	/// <returns></returns>
 	ValueTask<IReadOnlyList<CameraInfo>> GetAvailableCameras(CancellationToken token);
+
+	/// <summary>
+	/// Occurs when an image is captured by the camera.
+	/// </summary>
+	/// <param name="imageData">The image data held within a <see cref="Stream"/>.</param>
+	internal void OnMediaCaptured(Stream imageData);
+
+	/// <summary>
+	/// Occurs when an image capture fails.
+	/// </summary>
+	/// <param name="failureReason">A string containing the reason why the capture attempt failed.</param>
+	internal void OnMediaCapturedFailed(string failureReason);
 }
diff --git a/src/CommunityToolkit.Maui.Camera/Primitives/CameraFlashMode.shared.cs b/src/CommunityToolkit.Maui.Camera/Primitives/CameraFlashMode.shared.cs
@@ -1,4 +1,4 @@
-﻿namespace CommunityToolkit.Maui.Core.Primitives;
+﻿namespace CommunityToolkit.Maui.Core;
 
 /// <summary>
 /// Enumeration of the possible flash modes supported by the camera.
diff --git a/src/CommunityToolkit.Maui.Camera/Primitives/CameraPosition.shared.cs b/src/CommunityToolkit.Maui.Camera/Primitives/CameraPosition.shared.cs
@@ -1,4 +1,4 @@
-﻿namespace CommunityToolkit.Maui.Core.Primitives;
+﻿namespace CommunityToolkit.Maui.Core;
 
 /// <summary>
 /// Enumeration of the possible positions that a camera can be placed.
diff --git a/src/CommunityToolkit.Maui.Camera/Primitives/CameraViewDefaults.shared.cs b/src/CommunityToolkit.Maui.Camera/Primitives/CameraViewDefaults.shared.cs
@@ -1,8 +1,8 @@
 using System.ComponentModel;
 using System.Runtime.Versioning;
 using System.Windows.Input;
-using CommunityToolkit.Maui.Core.Primitives;
 using CommunityToolkit.Maui.Views;
+
 namespace CommunityToolkit.Maui.Core;
 
 /// <summary>Default Values for <see cref="ICameraView"/>"/></summary>
@@ -59,6 +59,6 @@ internal static Command<CancellationToken> CreateStartCameraPreviewCommand(Binda
 	internal static ICommand CreateStopCameraPreviewCommand(BindableObject bindable)
 	{
 		var cameraView = (CameraView)bindable;
-		return new Command(token => cameraView.StopCameraPreview());
+		return new Command(_ => cameraView.StopCameraPreview());
 	}
 }
diff --git a/src/CommunityToolkit.Maui.Camera/Primitives/MediaCaptureFailedEventArgs.shared.cs b/src/CommunityToolkit.Maui.Camera/Primitives/MediaCaptureFailedEventArgs.shared.cs
@@ -1,4 +1,4 @@
-﻿namespace CommunityToolkit.Maui.Views;
+﻿namespace CommunityToolkit.Maui.Core;
 
 /// <summary>
 /// Event args containing all contextual information related to a media capture failure event.
diff --git a/src/CommunityToolkit.Maui.Camera/Primitives/MediaCapturedEventArgs.shared.cs b/src/CommunityToolkit.Maui.Camera/Primitives/MediaCapturedEventArgs.shared.cs
@@ -1,4 +1,4 @@
-﻿namespace CommunityToolkit.Maui.Views;
+﻿namespace CommunityToolkit.Maui.Core;
 
 /// <summary>
 /// Event args containing all contextual information related to media capture event.
diff --git a/src/CommunityToolkit.Maui.Camera/Providers/CameraProvider.android.cs b/src/CommunityToolkit.Maui.Camera/Providers/CameraProvider.android.cs
@@ -7,7 +7,6 @@
 using AndroidX.Camera.Core;
 using AndroidX.Camera.Lifecycle;
 using AndroidX.Core.Content;
-using CommunityToolkit.Maui.Core.Primitives;
 using Java.Lang;
 
 namespace CommunityToolkit.Maui.Core;
diff --git a/src/CommunityToolkit.Maui.Camera/Providers/CameraProvider.macios.cs b/src/CommunityToolkit.Maui.Camera/Providers/CameraProvider.macios.cs
@@ -1,5 +1,4 @@
 ﻿using AVFoundation;
-using CommunityToolkit.Maui.Core.Primitives;
 using CoreMedia;
 using CoreVideo;
 using UIKit;
diff --git a/src/CommunityToolkit.Maui.Camera/Providers/CameraProvider.windows.cs b/src/CommunityToolkit.Maui.Camera/Providers/CameraProvider.windows.cs
@@ -1,4 +1,4 @@
-﻿using CommunityToolkit.Maui.Core.Primitives;
+﻿
 using CommunityToolkit.Maui.Extensions;
 using Windows.Devices.Enumeration;
 using Windows.Media.Capture;
diff --git a/src/CommunityToolkit.Maui.Camera/Views/CameraView.shared.cs b/src/CommunityToolkit.Maui.Camera/Views/CameraView.shared.cs
diff --git a/src/CommunityToolkit.Maui.UnitTests/Views/CameraView/CameraViewTests.cs b/src/CommunityToolkit.Maui.UnitTests/Views/CameraView/CameraViewTests.cs

Original file line number	Diff line number	Diff line change
`@@ -1,5 +1,4 @@`
`1`	`1`	`using System.Text;`
`2`		`-using CommunityToolkit.Maui.Core.Primitives;`
`3`	`2`
`4`	`3`	`#if IOS \|\| MACCATALYST`
`5`	`4`	`using AVFoundation;`
Original file line number	Diff line number	Diff line change
`@@ -1,5 +1,3 @@`
`1`		`-using CommunityToolkit.Maui.Core.Primitives;`
`2`		`-`
`3`	`1`	`namespace CommunityToolkit.Maui.Core;`
`4`	`2`
`5`	`3`	`partial class CameraManager`