[Proposal] CameraView minimal port

[CameraView minimal port]

• Proposed
• Prototype: Not Started
• Implementation: Not Started
  • iOS Support
  • Android Support
  • macOS Support
  • Windows Support
• Unit Tests: Not Started
• Sample: Not Started
• Documentation: Not Started

Link to Discussion

• #106
• #206

Summary

Today on XCT we have a very complete CameraView implementation but with a lot of bugs and a complex codebase to maintain. In the table below you can see all features implemented by each platform.

	Android	iOS	Windows
Preview	✅	✅	✅
Preview Aspect	✅	🚫	🚫
Mirror preview	✅	🚫	🚫
Zoom	✅	✅	✅
Take photo	✅	✅	✅
Flash	✅	✅	✅
Take video	✅	✅	✅
Record audio	✅	✅	✅
Video stabilization	✅	✅	✅

My plan, described in discussion #206, is to drop some features for the v1.0 of this lib. and use CameraX implementation for Android. You can see in the table below what features we will have for v1.0.

	Android	iOS	Windows
Preview	✅	✅	✅
Take photo	✅	✅	✅
Flash	✅	✅	✅

After this first implementation, we can add the missing features to all platforms.

Motivation

The motivation for this plan was the fact that CameraView lacks in quality right now and this’s our chance to fix it and provide a more reliable Camera control for our community.

Detailed Design

CameraView.shared.cs

public class CameraView : View
{
  public static readonly BindableProperty IsCameraViewBusyProperty;
  public static readonly BindableProperty IsAvailableProperty;
  public static readonly BindableProperty FlashModeProperty;
  
  // Use WeakEventManager 
  public event EventHandler<bool>? OnAvailable;
  public event EventHandler<MediaCapturedEventArgs>? MediaCaptured; 
  public event EventHandler<string>? MediaCaptureFailed;
  
  public bool IsCameraViewBusy { get; }
  public bool IsAvailable { get; }
  public CameraOptions CameraOptions { get; set; } 
  public void Shutter();
}

Usage Syntax

XAML Usage

<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:xct="http://xamarin.com/schemas/2020/toolkit"
             x:Class="MyLittleApp.MainPage">

     <StackLayout>
        <xct:CameraView
                x:Name="cameraView"
                FlashMode="On"
                MediaCaptured="CameraView_MediaCaptured"
                HorizontalOptions="FillAndExpand"
                VerticalOptions="FillAndExpand" />
    </StackLayout>
</ContentPage>

C# Usage

class MyPage : ContentPage
{
  public MyPage()
  {
    Content = new CameraView
    {
      FlashMode = CameraFlashMode.Off,
    }.FillAndExpand()
     .Invoke(cameraView => cameraView.MediaCaptured += HandleMediaCaptured);
  }

  void HandleMediaCaptured(object? sender, MediaCapturedEventArgs e)
  {
    //...
  }
}

Drawbacks

We will (probably*) break our users on v1.0 since the API will be missing a lot of features.

• there’s a chance that we can implement all features for v1.0 if we have a lot of community help.

Alternatives

• Follow the #106 proposal and just port the XCT code to here, but with that, we will bring all issues (if we don’t solve them during the port, what I believe it’s very hard to do)

Unresolved Questions

[vanyok1991]

Hi, any updates when Camera View will be released?

[hjam40]

Hi,

I have implemented a CameraView for all platforms with Zxing codebar detecting integrated if you wanna try it Camera.MAUI. If you are interested I could integrate it here.