CanvasView.Touch not firing all events on iOS

[nm4568]

Description

CanvasView.Touch is only fired on Pressed on iOS

Code

Minimal Reproducible Example - https://github.com/nm4568/SkiaSharpSamples

But, you can also share a short block of code here:

using SkiaSharp;
using SkiaSharp.Views.Maui;
using SKCanvasView = SkiaSharp.Views.Maui.Controls.SKCanvasView;

namespace SkiaSharpSample
{
    public partial class MainPage : ContentPage
    {
        SKBitmap skBitmap;

        public MainPage()
        {
            InitializeComponent();

            skCanvasView.EnableTouchEvents = true;
            skCanvasView.PaintSurface += View_PaintSurface;
            skCanvasView.Touch += SkCanvasView_Touch;
        }

        protected override void OnAppearing()
        {
            base.OnAppearing();

            // Load and render a PNG image using SkiaSharp
            RenderSkiaSharpImage();
        }

        private void RenderSkiaSharpImage()
        {
            // Get the stream of the embedded resource
            var stream = typeof(MainPage).Assembly.GetManifestResourceStream("SkiaSharpSample.Resources.Images.dotnet_bot.png");

            // Create a SKBitmap from the stream
            skBitmap = SKBitmap.Decode(stream);

        }

        private void SkCanvasView_Touch(object? sender, SkiaSharp.Views.Maui.SKTouchEventArgs e)
        {
            switch (e.ActionType)
            {
                case SKTouchAction.Entered:
                    DebugLabel.Text = "Entered";
                    break;
                case SKTouchAction.Pressed:
                    DebugLabel.Text = "Pressed";
                    break;
                case SKTouchAction.Moved:
                    DebugLabel.Text = "Moved";
                    break;
                case SKTouchAction.Released:
                    DebugLabel.Text = "Released";
                    break;
                case SKTouchAction.Cancelled:
                    DebugLabel.Text = "Canceled";
                    break;
                case SKTouchAction.Exited:
                    DebugLabel.Text = "Exited";
                    break;
            }

            // Invalidate the canvas to trigger a redraw
            ((SKCanvasView)sender).InvalidateSurface();
        }

        private void View_PaintSurface(object? sender, SkiaSharp.Views.Maui.SKPaintSurfaceEventArgs e)
        {
            // Get the SKCanvas from the event arguments
            var canvas = e.Surface.Canvas;

            // Clear the canvas
            canvas.Clear(SKColors.White);

            // Draw the SKBitmap onto the canvas
            canvas.DrawBitmap(skBitmap, new SKPoint(0, 0));
        }
    }
}

You can also share some XAML:

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:skia="clr-namespace:SkiaSharp.Views.Maui.Controls;assembly=SkiaSharp.Views.Maui.Controls"
             x:Class="SkiaSharpSample.MainPage">
<StackLayout>
        <skia:SKCanvasView x:Name="skCanvasView" PaintSurface="View_PaintSurface" HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand"/>
        <Label x:Name="DebugLabel"
               FontSize="20"
               HorizontalOptions="Center"
               VerticalOptions="End" />
    </StackLayout>
</ContentPage>

Expected Behavior

Events with all other ActionTypes should be fired.

Actual Behavior

CanvasView.Touch is only firing one ActionType on iOS - ActionType.Pressed.

Version of SkiaSharp

2.88.3 (Current)

Last Known Good Version of SkiaSharp

Other (Please indicate in the description)

IDE / Editor

Visual Studio (Windows)

Platform / Operating System

iOS

Platform / Operating System Version

iOS 17.2

Devices

iOS Simulator - iPhone 14 Pro Max

Relevant Screenshots

No response

Relevant Log Output

No response

Code of Conduct

• [X] I agree to follow this project's Code of Conduct

[pauldendulk]

We have this problem in Mapsui.

I would also be interested to hear about the roadmap of SkiaSharp touch. It seems to me a difficult problem to deal with touch on all the platforms, and there were some changes in the api in the past. Perhaps we should use the touch of the platform itself instead of SkiaSharp. Any advise is welcome.

[pauldendulk]

Heya! Just realized that your test needs to set e.Handled = true; at the end of the OnTouch handler. If you update the sample and it behaves correctly we have to investigate Mapsui again.

See: https://github.com/mono/SkiaSharp/issues/334