Upgrade to Avalonia 12.0

[wieslawsoltes]

Avalonia 12.0.0 upgrade

Summary

This branch updates the Avalonia integration in Svg.Skia to stable 12.0.0, retargets the Avalonia-specific packages to supported TFMs, migrates the remaining Avalonia 12 API breakages in controls, editor code, and samples, switches optional devtools support to ProDiagnostics, and updates the docs/test infrastructure to match the new Avalonia lane.

Key changes

Package and version updates

• Directory.Packages.props
  • Bumps the Avalonia package family to 12.0.0.
  • Replaces Avalonia.Diagnostics with opt-in ProDiagnostics.
  • Adds xunit.v3 centrally for the Avalonia headless test projects.
• Directory.Build.props
  • Updates package metadata to VersionPrefix=4.0.0.
  • Sets AvaloniaVersionPrefix=12.0.0.
• build/SkiaSharp.v3.props and build/SkiaSharp.Native.v3.props
  • Align the SkiaSharp v3 overrides to 3.119.3-preview.1.1, which is required by the Avalonia 12 dependency chain.
• build/ReactiveUI.Avalonia.props
  • Replaces the old Avalonia ReactiveUI props wiring with ReactiveUI.Avalonia for TestApp.

Avalonia project targeting and test infrastructure

• Skia.Controls.Avalonia, Svg.Controls.Avalonia, Svg.Controls.Skia.Avalonia, Svg.Editor.Avalonia, and Svg.Editor.Skia.Avalonia
  • Retarget from the old multi-TFM matrix to net8.0;net10.0.
• TestApp and AvaloniaSKPictureImageSample
  • Disable compiled bindings by default where the Avalonia 12 migration path needs it.
• Avalonia unit test projects
  • Switch to xunit.v3 and OutputType=Exe for the Avalonia headless host.
• tests/Avalonia.Svg.Skia.UiTests/Avalonia.Svg.Skia.UiTests.csproj
  • Drops stale Linux-specific props imports that are no longer part of this test lane.

Avalonia 12 API migrations

• src/Svg.Controls.Avalonia/AvaloniaSvgAssetLoader.cs
  • Updates glyph measurement to the Avalonia 12 glyph-typeface APIs using CharacterToGlyphMap and TryGetHorizontalGlyphAdvance.
• src/Svg.Editor.Skia.Avalonia/SvgEditorWorkspace.axaml.cs
  • Migrates drag/drop to DataTransfer, TryGetFiles(), and DragDrop.DoDragDropAsync(...).
  • Updates tree container access to ContainerFromIndex(...).
• samples/AvaloniaSvgSample/MainWindow.axaml.cs
• samples/AvaloniaSvgSkiaSample/MainWindow.axaml.cs
• samples/TestApp/Services/StorageService.cs
  • Move file drag/drop and storage-provider access to the Avalonia 12 APIs.
• src/Svg.Editor.Avalonia/InsertElementPickerView.axaml.cs
• src/Svg.Editor.Avalonia/SymbolPickerView.axaml.cs
  • Update focus handlers from GotFocusEventArgs to FocusChangedEventArgs.
• Avalonia views such as samples/TestApp/Views/MainView.axaml
  • Replace Watermark with PlaceholderText where required by Avalonia 12.

Samples, diagnostics, and docs

• Sample windows no longer unconditionally call AttachDevTools() in debug builds.
• build/Avalonia.Diagnostics.props
  • Makes diagnostics opt-in via UseAvaloniaDiagnostics=true and routes that to ProDiagnostics.
• .github/workflows/docs.yml
  • Splits docs into a build job plus a push-only deploy job so pull requests stop attempting Pages deployment.
• site/config.scriban and related docs articles
  • Keep netstandard2.0 as the default API extraction target, while overriding the Avalonia 12 packages to net8.0 and the Uno control package to net10.0.

Validation

Validated with:

dotnet build Svg.Skia.slnx -c Release
dotnet test Svg.Skia.slnx -c Release --no-build

Observed results from the latest full solution run:

• ShimSkiaSharp.UnitTests: 128 passed
• Svg.Model.UnitTests: 64 passed
• Svg.Editor.Skia.UnitTests: 10 passed
• Svg.Editor.Svg.UnitTests: 4 passed
• Svg.Controls.Skia.Uno.UnitTests: 17 passed
• Svg.Controls.Avalonia.UnitTests: 10 passed
• Svg.Controls.Skia.Avalonia.UnitTests: 19 passed
• Svg.Editor.Skia.Avalonia.UnitTests: 18 passed
• Svg.Skia.UnitTests: 1327 passed, 769 skipped

No test failures were observed in the final branch state.

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[chatgpt-codex-connector]

Replace invalid diagnostics package ID

ProDiagnostics is wired as the central diagnostics package version, but this repo’s NuGet.Config only allows nuget.org and Avalonia’s own tooling docs/packages use AvaloniaUI.DiagnosticsSupport (with Avalonia.Diagnostics explicitly deprecated). Because all sample projects import build/Avalonia.Diagnostics.props, restore will attempt to resolve ProDiagnostics at $(AvaloniaVersion) and fail with a missing-package error on a clean environment.

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[wieslawsoltes]

Re-checked this after 784f10b9f74cb35512a77fc2b68ac343f9b9d18e (Use ProDiagnostics for devtools) and 1aaaa347d04eb6c579a3b71f942438a090ad8149 (Always reference ProDiagnostics). No code rollback was needed: ProDiagnostics is published on nuget.org, including 12.0.0 (https://api.nuget.org/v3-flatcontainer/prodiagnostics/index.json lists it), and the branch currently restores/builds successfully with the shared build/Avalonia.Diagnostics.props import in place. I also reran dotnet build Svg.Skia.slnx -c Release on the current branch after making the diagnostics wiring unconditional.