Add HtmlRenderer.WinUI adapter for WinUI 3 / Win2D

.github/workflows/build.yml

@@ -45,11 +45,23 @@ jobs:
     - name: Verify SDK Installation
       run: dotnet --info
 
+    - name: Select build target
+      id: build-target
+      run: |
+        # HtmlRenderer.WinUI/HtmlRenderer.Demo.WinUI (Windows App SDK/Win2D, MSIX PRI generation via
+        # native makepri.exe/makeappx.exe) can only build on Windows - unlike the WinForms/WPF adapters,
+        # which cross-compile cleanly everywhere via EnableWindowsTargeting's reference-assembly story,
+        # there is no non-Windows equivalent for those native tools at all. Non-Windows runners build a
+        # solution filter excluding just those two projects; everything else still builds and tests
+        # identically on every OS.
+        $target = $IsWindows ? "Source/HtmlRenderer.sln" : "Source/HtmlRenderer.CrossPlatform.slnf"
+        echo "path=$target" >> $env:GITHUB_OUTPUT
+
     - name: Restore Dependencies
-      run: dotnet restore Source/HtmlRenderer.sln
+      run: dotnet restore ${{ steps.build-target.outputs.path }}
 
     - name: Build
-      run: dotnet build Source/HtmlRenderer.sln --configuration Release --no-restore
+      run: dotnet build ${{ steps.build-target.outputs.path }} --configuration Release --no-restore
 
     - name: Run Tests
       if: runner.os == 'Windows'

Source/Demo/WinUI/App.xaml

@@ -0,0 +1,16 @@
+<Application
+    x:Class="TheArtOfDev.HtmlRenderer.Demo.WinUI.App"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+
+    <Application.Resources>
+        <ResourceDictionary>
+            <ResourceDictionary.MergedDictionaries>
+                <!-- Supplies the shared theme resources (e.g. TabViewButtonBackground) that TreeView's
+                     own default style depends on - without this, any non-trivial control throws a
+                     XamlParseException at InitializeComponent time because those keys don't exist. -->
+                <XamlControlsResources xmlns="using:Microsoft.UI.Xaml.Controls" />
+            </ResourceDictionary.MergedDictionaries>
+        </ResourceDictionary>
+    </Application.Resources>
+</Application>

Source/Demo/WinUI/App.xaml.cs

@@ -0,0 +1,37 @@
+// "Therefore those skilled at the unorthodox
+// are infinite as heaven and earth,
+// inexhaustible as the great rivers.
+// When they come to an end,
+// they begin again,
+// like the days and months;
+// they die and are reborn,
+// like the four seasons."
+//
+// - Sun Tsu,
+// "The Art of War"
+
+using Microsoft.UI.Xaml;
+
+namespace TheArtOfDev.HtmlRenderer.Demo.WinUI
+{
+    /// <summary>
+    /// Minimal application entry point - hosts one <see cref="MainWindow"/> with a single
+    /// <see cref="TheArtOfDev.HtmlRenderer.WinUI.HtmlPanel"/> rendering a hardcoded sample document, just
+    /// enough to prove the WinUI 3 control renders real HTML end to end.
+    /// </summary>
+    public partial class App : Application
+    {
+        private Window _window;
+
+        public App()
+        {
+            InitializeComponent();
+        }
+
+        protected override void OnLaunched(LaunchActivatedEventArgs args)
+        {
+            _window = new MainWindow();
+            _window.Activate();
+        }
+    }
+}

Source/Demo/WinUI/HtmlRenderer.Demo.WinUI.csproj

@@ -0,0 +1,33 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net8.0-windows10.0.19041.0</TargetFramework>
+    <TargetPlatformMinVersion>10.0.17763.0</TargetPlatformMinVersion>
+    <OutputType>WinExe</OutputType>
+    <RootNamespace>TheArtOfDev.HtmlRenderer.Demo.WinUI</RootNamespace>
+    <AssemblyName>HtmlRendererWinUIDemo</AssemblyName>
+    <UseWinUI>true</UseWinUI>
+    <EnableWindowsTargeting>true</EnableWindowsTargeting>
+    <GenerateResourceUsePreserializedResources>true</GenerateResourceUsePreserializedResources>
+    <!-- Unpackaged WinUI 3 app: WindowsPackageType=None + a self-contained deploy (both the .NET runtime
+         and the Windows App SDK runtime), since an unpackaged app has no MSIX identity to resolve a
+         framework-package dependency through - a genuinely new deployment concern the WPF/WinForms demos
+         don't have (see the plan's Decisions section). -->
+    <WindowsPackageType>None</WindowsPackageType>
+    <WindowsAppSDKSelfContained>true</WindowsAppSDKSelfContained>
+    <SelfContained>true</SelfContained>
+    <RuntimeIdentifier>win-x64</RuntimeIdentifier>
+    <Platforms>x64</Platforms>
+  </PropertyGroup>
+  <PropertyGroup>
+    <ApplicationManifest>app.manifest</ApplicationManifest>
+  </PropertyGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\..\HtmlRenderer.WinUI\HtmlRenderer.WinUI.csproj" />
+    <ProjectReference Include="..\..\HtmlRenderer\HtmlRenderer.csproj" />
+    <ProjectReference Include="..\Common\HtmlRenderer.Demo.Common.csproj" />
+  </ItemGroup>
+  <ItemGroup>
+    <PackageReference Include="Microsoft.WindowsAppSDK" Version="2.4.0" />
+    <PackageReference Include="Microsoft.Graphics.Win2D" Version="1.4.*" />
+  </ItemGroup>
+</Project>

Source/Demo/WinUI/MainWindow.xaml

@@ -0,0 +1,20 @@
+<Window
+    x:Class="TheArtOfDev.HtmlRenderer.Demo.WinUI.MainWindow"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:winui="using:TheArtOfDev.HtmlRenderer.WinUI">
+
+    <Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
+        <Grid.ColumnDefinitions>
+            <ColumnDefinition Width="280"/>
+            <ColumnDefinition Width="*"/>
+        </Grid.ColumnDefinitions>
+
+        <TreeView x:Name="SamplesTreeView"
+                  Grid.Column="0"
+                  SelectionMode="Single"
+                  SelectionChanged="OnSamplesTreeViewSelectionChanged"/>
+
+        <winui:HtmlPanel x:Name="RendererPanel" Grid.Column="1" />
+    </Grid>
+</Window>

Source/Demo/WinUI/MainWindow.xaml.cs

@@ -0,0 +1,179 @@
+// "Therefore those skilled at the unorthodox
+// are infinite as heaven and earth,
+// inexhaustible as the great rivers.
+// When they come to an end,
+// they begin again,
+// like the days and months;
+// they die and are reborn,
+// like the four seasons."
+//
+// - Sun Tsu,
+// "The Art of War"
+
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.IO;
+using System.Threading.Tasks;
+using Microsoft.Graphics.Canvas;
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Controls;
+using TheArtOfDev.HtmlRenderer.Core.Entities;
+using TheArtOfDev.HtmlRenderer.Demo.Common;
+using Windows.Storage.Streams;
+
+namespace TheArtOfDev.HtmlRenderer.Demo.WinUI
+{
+    /// <summary>
+    /// Hosts a <see cref="TreeView"/> of the same showcase/test/performance samples the WPF and WinForms
+    /// demos expose (via the shared, UI-framework-agnostic <see cref="SamplesLoader"/>/<see cref="HtmlSample"/>
+    /// from <c>HtmlRenderer.Demo.Common</c>) next to a <see cref="TheArtOfDev.HtmlRenderer.WinUI.HtmlPanel"/>
+    /// that renders whichever sample is selected.
+    /// </summary>
+    /// <remarks>
+    /// Node content is a plain <see cref="string"/> (the sample/category name), matching Microsoft's own
+    /// documented <c>RootNodes</c> pattern exactly (see
+    /// https://learn.microsoft.com/en-us/windows/apps/develop/ui/controls/tree-view) - no
+    /// <see cref="TreeView.ItemTemplate"/> is needed for that case, since a string displays directly. An
+    /// earlier version wrapped each node's content in a custom object and bound it via
+    /// <c>TreeView.ItemTemplate</c>'s <c>{Binding Name}</c>, which rendered no text and never expanded -
+    /// switched to this simpler, documented shape instead of chasing the exact binding-context rules for
+    /// that pattern. <see cref="_nodeToSample"/> maps each leaf node back to its <see cref="HtmlSample"/>
+    /// since the node's own displayed Content is just its name.
+    /// </remarks>
+    public sealed partial class MainWindow : Window
+    {
+        private readonly Dictionary<TreeViewNode, HtmlSample> _nodeToSample = new Dictionary<TreeViewNode, HtmlSample>();
+
+        public MainWindow()
+        {
+            InitializeComponent();
+
+            Title = "HTML Renderer - WinUI 3 Demo";
+
+            SamplesLoader.Init("WinUI", typeof(TheArtOfDev.HtmlRenderer.WinUI.HtmlRender).Assembly.GetName().Version.ToString());
+
+            // Without this, showcase samples' <link rel="Stylesheet" href="StyleSheet"> never resolves, so
+            // e.g. Intro.htm's `.whitehole { background-color:white; border-radius:10px }` class is simply
+            // never applied at all - not a paint bug, the rule itself never loads. DemoUtils.OnStylesheetLoad
+            // is the same platform-agnostic handler the WPF/WinForms demos use.
+            RendererPanel.StylesheetLoad += DemoUtils.OnStylesheetLoad;
+
+            // Same idea as StylesheetLoad above: samples reference icons by logical key (e.g.
+            // src="HtmlIcon") that DemoUtils.GetImageStream resolves to an embedded resource - without
+            // this, every such <img> falls through to the built-in "failed to load" icon instead.
+            RendererPanel.ImageLoad += OnImageLoad;
+
+            LoadSamples();
+        }
+
+        private void LoadSamples()
+        {
+            var showcaseRoot = new TreeViewNode { Content = "HTML Renderer" };
+            SamplesTreeView.RootNodes.Add(showcaseRoot);
+            foreach (var sample in SamplesLoader.ShowcaseSamples)
+                AddSampleNode(showcaseRoot, sample);
+
+            var testSamplesRoot = new TreeViewNode { Content = "Test Samples" };
+            SamplesTreeView.RootNodes.Add(testSamplesRoot);
+            foreach (var sample in SamplesLoader.TestSamples)
+                AddSampleNode(testSamplesRoot, sample);
+
+            if (SamplesLoader.PerformanceSamples.Count > 0)
+            {
+                var perfSamplesRoot = new TreeViewNode { Content = "Performance Samples" };
+                SamplesTreeView.RootNodes.Add(perfSamplesRoot);
+                foreach (var sample in SamplesLoader.PerformanceSamples)
+                    AddSampleNode(perfSamplesRoot, sample);
+            }
+
+            showcaseRoot.IsExpanded = true;
+            if (showcaseRoot.Children.Count > 0)
+            {
+                var firstNode = showcaseRoot.Children[0];
+                SamplesTreeView.SelectedNode = firstNode;
+                ShowSample(_nodeToSample[firstNode]);
+            }
+        }
+
+        private void AddSampleNode(TreeViewNode root, HtmlSample sample)
+        {
+            var node = new TreeViewNode { Content = sample.Name };
+            _nodeToSample[node] = sample;
+            root.Children.Add(node);
+        }
+
+        private void OnSamplesTreeViewSelectionChanged(TreeView sender, TreeViewSelectionChangedEventArgs args)
+        {
+            foreach (var node in sender.SelectedNodes)
+            {
+                if (_nodeToSample.TryGetValue(node, out var sample))
+                {
+                    ShowSample(sample);
+                    break;
+                }
+            }
+        }
+
+        private void ShowSample(HtmlSample sample)
+        {
+            try
+            {
+                RendererPanel.AvoidImagesLateLoading = !sample.FullName.Contains("Many images");
+                RendererPanel.Text = sample.Html;
+            }
+            catch (Exception ex)
+            {
+                Debug.WriteLine(ex);
+            }
+        }
+
+        /// <summary>
+        /// Resolves the demo's logical icon keys (e.g. <c>src="HtmlIcon"</c>) via
+        /// <see cref="DemoUtils.GetImageStream"/> - real URLs/paths DemoUtils doesn't recognize fall
+        /// through untouched (<see cref="HtmlImageLoadEventArgs.Handled"/> left false) so the default
+        /// loader still handles them.
+        /// </summary>
+        private void OnImageLoad(object sender, HtmlImageLoadEventArgs e)
+        {
+            var stream = DemoUtils.GetImageStream(e.Src);
+            if (stream == null)
+                return;
+
+            e.Handled = true;
+            _ = LoadIconAsync(e, stream);
+        }
+
+        private static async Task LoadIconAsync(HtmlImageLoadEventArgs e, Stream stream)
+        {
+            try
+            {
+                byte[] bytes;
+                using (stream)
+                using (var memory = new MemoryStream())
+                {
+                    await stream.CopyToAsync(memory).ConfigureAwait(false);
+                    bytes = memory.ToArray();
+                }
+
+                using var randomAccessStream = new InMemoryRandomAccessStream();
+                using (var writer = new DataWriter(randomAccessStream.GetOutputStreamAt(0)))
+                {
+                    writer.WriteBytes(bytes);
+                    await writer.StoreAsync();
+                    await writer.FlushAsync();
+                    writer.DetachStream();
+                }
+                randomAccessStream.Seek(0);
+
+                var bitmap = await CanvasBitmap.LoadAsync(CanvasDevice.GetSharedDevice(), randomAccessStream);
+                e.Callback(bitmap);
+            }
+            catch (Exception ex)
+            {
+                Debug.WriteLine(ex);
+                e.Callback();
+            }
+        }
+    }
+}

Source/Demo/WinUI/app.manifest

@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="utf-8"?>
+<assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1">
+  <assemblyIdentity version="1.0.0.0" name="HtmlRenderer.Demo.WinUI.app"/>
+  <trustInfo xmlns="urn:schemas-microsoft-com:asm.v2">
+    <security>
+      <requestedPrivileges xmlns="urn:schemas-microsoft-com:asm.v3">
+        <requestedExecutionLevel level="asInvoker" uiAccess="false"/>
+      </requestedPrivileges>
+    </security>
+  </trustInfo>
+  <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
+    <application>
+      <!-- Windows Vista -->
+      <supportedOS Id="{e2011457-1546-43c5-a5fe-008deee3d3f0}" />
+      <!-- Windows 7 -->
+      <supportedOS Id="{35138b9a-5d96-4fbd-8e2d-a2440225f93a}" />
+      <!-- Windows 8 -->
+      <supportedOS Id="{4a2f28e3-53b9-4441-ba9c-d69d4a4a6e38}" />
+      <!-- Windows 8.1 -->
+      <supportedOS Id="{1f676c76-80e1-4239-95bb-83d0f6d0da78}" />
+      <!-- Windows 10/11 -->
+      <supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}" />
+    </application>
+  </compatibility>
+  <application xmlns="urn:schemas-microsoft-com:asm.v3">
+    <windowsSettings>
+      <dpiAwareness xmlns="http://schemas.microsoft.com/SMI/2016/WindowsSettings">PerMonitorV2</dpiAwareness>
+      <longPathAware xmlns="http://schemas.microsoft.com/SMI/2016/WindowsSettings">true</longPathAware>
+    </windowsSettings>
+  </application>
+</assembly>

Source/HtmlRenderer.CrossPlatform.slnf

@@ -0,0 +1,17 @@
+{
+  "solution": {
+    "path": "HtmlRenderer.sln",
+    "projects": [
+      "Demo\\Common\\HtmlRenderer.Demo.Common.csproj",
+      "Demo\\WinForms\\HtmlRenderer.Demo.WinForms.csproj",
+      "Demo\\WPF\\HtmlRenderer.Demo.WPF.csproj",
+      "HtmlRenderer\\HtmlRenderer.csproj",
+      "HtmlRenderer.PdfSharp\\HtmlRenderer.PdfSharp.csproj",
+      "HtmlRenderer.WinForms\\HtmlRenderer.WinForms.csproj",
+      "HtmlRenderer.WPF\\HtmlRenderer.WPF.csproj",
+      "Test\\HtmlRenderer.IntegrationTest\\HtmlRenderer.IntegrationTest.csproj",
+      "Test\\HtmlRenderer.PdfSharp.Test\\HtmlRenderer.PdfSharp.Test.csproj",
+      "Test\\HtmlRenderer.Test\\HtmlRenderer.Test.csproj"
+    ]
+  }
+}