Fix Avalonia Event Bubbling

[JaggerJo]

Seems like the Focus refactoring in Avalonia v12 might have caused some issues with Pointer Capturing and Event Bubbling.

We've been using version 1.0.0.18 and recently updated to 4.2.0. We just discovered that buttons with SVG icons in them are no longer clickable.

I first thought this is related to focus refactoring in v12 - but it seems like this only has to do with changes / the addition of the interaction system.

↓ With Avalonia v12 + current master

↓ With the fix

Demo App

Project File

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net9.0</TargetFramework>
    <Nullable>enable</Nullable>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Avalonia" Version="12.0.1" />
    <PackageReference Include="Avalonia.Desktop" Version="12.0.1" />
    <PackageReference Include="Avalonia.Themes.Fluent" Version="12.0.1" />
    <!-- Reproduces against the published broken version. -->
    <PackageReference Include="Svg.Controls.Skia.Avalonia" Version="12.0.0.5" />
  </ItemGroup>

</Project>

using Avalonia;
using Avalonia.Controls;
using Avalonia.Controls.ApplicationLifetimes;
using Avalonia.Layout;
using Avalonia.Themes.Fluent;
using AvSvg = Avalonia.Svg.Skia.Svg;

AppBuilder.Configure<App>().UsePlatformDetect().StartWithClassicDesktopLifetime(args);

public sealed class App : Application
{
    public override void Initialize() => Styles.Add(new FluentTheme());

    public override void OnFrameworkInitializationCompleted()
    {
        const string svg = "<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 100'>" +
                           "<circle cx='50' cy='50' r='44' fill='#3B82F6'/></svg>";

        int btn = 0, brd = 0;
        var status = new TextBlock { HorizontalAlignment = HorizontalAlignment.Center };
        void Refresh() => status.Text = $"button={btn}  border={brd}";
        Refresh();

        var button = new Button { Content = NewSvg(svg) };
        button.Click += (_, _) => { btn++; Refresh(); };

        var border = new Border { Padding = new Thickness(8), Child = NewSvg(svg) };
        border.Tapped += (_, _) => { brd++; Refresh(); };

        ((IClassicDesktopStyleApplicationLifetime)ApplicationLifetime!).MainWindow = new Window
        {
            Width = 320, Height = 280, Title = "Svg pointer-bubble repro",
            Content = new StackPanel
            {
                Margin = new Thickness(20), Spacing = 12,
                HorizontalAlignment = HorizontalAlignment.Center,
                VerticalAlignment = VerticalAlignment.Center,
                Children = { button, border, status },
            },
        };
        base.OnFrameworkInitializationCompleted();
    }

    private static AvSvg NewSvg(string source) => new(new System.Uri("avares://SvgBubbleRepro/"))
    {
        Source = source, Width = 80, Height = 80,
    };
}

[wieslawsoltes]

@codex review

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Restore pointer capture on press to avoid stuck SVG capture

Without capturing the Avalonia pointer on press, a PointerReleased that occurs outside this control will not be delivered here, so Interaction.DispatchPointerReleased(...) never runs to clear the dispatcher’s internal _capturedElement/_pressedElement state. In that path, later DispatchPointerMoved calls continue routing to the stale captured SVG element (_capturedElement ?? hitTarget), which breaks hover/cursor updates and event targeting after an outside release until another full press/release cycle happens.

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[JaggerJo]

@wieslawsoltes anything I can do to get a fix in? :)

[wieslawsoltes]

@JaggerJo Thanks for PR, sorry for long time to merge but have huge backlog of PRs for Svg.Skia

[JaggerJo]

@JaggerJo Thanks for PR, sorry for long time to merge but have huge backlog of PRs for Svg.Skia

No worries - thanks for all the OSS work 👏