From c8661c9ad292fa2a32a4e782476adf93b8be206a Mon Sep 17 00:00:00 2001
From: Siegfried Pammer <siegfriedpammer@gmail.com>
Date: Thu, 14 May 2026 18:44:47 +0200
Subject: [PATCH] =?UTF-8?q?BAML=E2=86=92XAML=20integration=20for=20resourc?=
 =?UTF-8?q?e=20viewer=20+=20project=20export?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Adds ICSharpCode.BamlDecompiler as a ProjectReference, ports IResourceFileHandler +
ResourceFileHandlerContext from WPF, and plumbs both through:

Assisted-by: Claude:claude-opus-4-7:Claude Code
---
 ILSpy.Tests/Resources/BamlResourceTests.cs    | 138 ++++++++++++++++++
 ILSpy.Tests/Resources/ResourceFactoryTests.cs |   1 +
 ILSpy/ILSpy.csproj                            |   1 +
 ILSpy/Languages/CSharpLanguage.cs             |  65 ++++++++-
 ILSpy/Languages/IResourceFileHandler.cs       |  81 ++++++++++
 ILSpy/TreeNodes/BamlResourceEntryNode.cs      |  80 ++++++++++
 ILSpy/TreeNodes/BamlResourceNodeFactory.cs    | 108 ++++++++++++++
 7 files changed, 473 insertions(+), 1 deletion(-)
 create mode 100644 ILSpy.Tests/Resources/BamlResourceTests.cs
 create mode 100644 ILSpy/Languages/IResourceFileHandler.cs
 create mode 100644 ILSpy/TreeNodes/BamlResourceEntryNode.cs
 create mode 100644 ILSpy/TreeNodes/BamlResourceNodeFactory.cs

diff --git a/ILSpy.Tests/Resources/BamlResourceTests.cs b/ILSpy.Tests/Resources/BamlResourceTests.cs
new file mode 100644
index 000000000..821b11922
--- /dev/null
+++ b/ILSpy.Tests/Resources/BamlResourceTests.cs
@@ -0,0 +1,138 @@
+// Copyright (c) 2026 AlphaSierraPapa for the SharpDevelop Team
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this
+// software and associated documentation files (the "Software"), to deal in the Software
+// without restriction, including without limitation the rights to use, copy, modify, merge,
+// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
+// to whom the Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all copies or
+// substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
+// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+using System.Linq;
+
+using Avalonia.Headless.NUnit;
+
+using AwesomeAssertions;
+
+using ICSharpCode.Decompiler;
+using ICSharpCode.Decompiler.Metadata;
+using ICSharpCode.ILSpyX.Abstractions;
+
+using ILSpy;
+using ILSpy.AppEnv;
+using ILSpy.Baml;
+using ILSpy.Languages;
+using ILSpy.TreeNodes;
+using ILSpy.Views;
+
+using NUnit.Framework;
+
+using IResourceFileHandler = ILSpy.Languages.IResourceFileHandler;
+using ResourceFileHandlerContext = ILSpy.Languages.ResourceFileHandlerContext;
+
+namespace ICSharpCode.ILSpy.Tests;
+
+[TestFixture]
+public class BamlResourceTests
+{
+	// Boot composition once per test so AppComposition.Current is live for the MEF lookups
+	// the factory/handler depend on. Resolving the MainWindow type forces App.Initialize.
+	static void EnsureComposition() => AppComposition.Current.GetExport<MainWindow>();
+
+	[AvaloniaTest]
+	public void Factory_Creates_BamlResourceEntryNode_For_Baml_Resource()
+	{
+		// The MEF-discovered BamlResourceNodeFactory must claim any `.baml`-named resource
+		// and wrap it in a BamlResourceEntryNode, regardless of the bytes inside the stream.
+		// Routing is name-based, mirroring the XML / image / cursor factories — actual BAML
+		// parsing happens lazily when the user selects the node.
+
+		// Arrange — boot composition; build a dummy .baml-named resource (bytes don't matter
+		// for the routing decision).
+		EnsureComposition();
+		var resource = new ByteArrayResource("Pages/MyWindow.baml", new byte[] { 0, 1, 2 });
+
+		// Act — dispatch through the central resource factory pipeline.
+		var node = ResourceEntryNode.Create(resource);
+
+		// Assert — comes back as a BamlResourceEntryNode, not the generic fallback.
+		node.GetType().Should().Be(typeof(BamlResourceEntryNode));
+	}
+
+	[AvaloniaTest]
+	public void Factory_Ignores_Non_Baml_Resource_Names()
+	{
+		// The BAML factory must only claim `.baml` resources. Anything else flows through
+		// to other factories or the generic ResourceTreeNode fallback. A misfire here would
+		// hijack arbitrary streams and crash on first selection (XamlDecompiler.Decompile
+		// throws on non-BAML input).
+
+		// Arrange + Act — feed a non-baml name straight to the BAML factory.
+		var factory = new BamlResourceNodeFactory();
+		var node = factory.CreateNode(new ByteArrayResource("readme.txt", new byte[] { 0, 1, 2 }));
+
+		// Assert — factory yields null so the dispatcher tries the next candidate.
+		node.Should().BeNull();
+	}
+
+	[AvaloniaTest]
+	public void File_Handler_Claims_Baml_Extension_Case_Insensitive()
+	{
+		// During project export the handler is consulted via CanHandle; first claim wins.
+		// The match is case-insensitive on the extension (`.BAML` from an obfuscated assembly
+		// must still produce a XAML output).
+
+		// Arrange — boot composition; build a context with a default DecompilationOptions
+		// (the handler doesn't touch the options for CanHandle).
+		EnsureComposition();
+		var handler = new BamlResourceFileHandler();
+		var context = new ResourceFileHandlerContext(new DecompilationOptions());
+
+		// Act + Assert — three positive variants and two rejections.
+		handler.CanHandle("MainWindow.baml", context).Should().BeTrue();
+		handler.CanHandle("themes/Generic.BAML", context).Should().BeTrue();
+		handler.CanHandle("Resources/Strings.baml", context).Should().BeTrue();
+		handler.CanHandle("readme.txt", context).Should().BeFalse();
+		handler.CanHandle("Window.xaml", context).Should().BeFalse();
+	}
+
+	[AvaloniaTest]
+	public void File_Handler_Reports_Page_Entry_Type()
+	{
+		// EntryType drives the MSBuild item group the produced file lands in. BAML→XAML
+		// must go under `<Page>` so MSBuild's XAML compiler picks it up and regenerates the
+		// matching .g.cs partial on rebuild — same as the WPF side.
+
+		// Arrange + Act + Assert — exact string match (case-sensitive; MSBuild element names
+		// are case-insensitive in practice but the canonical form is "Page").
+		new BamlResourceFileHandler().EntryType.Should().Be("Page");
+	}
+
+	[AvaloniaTest]
+	public void Mef_Discovers_Baml_Factory_And_File_Handler()
+	{
+		// Both exports must surface through AppComposition. If `[Export]` / `[Shared]` got
+		// dropped during a future refactor the pane would silently dump raw bytes for .baml
+		// and project export would emit a bare `EmbeddedResource` instead of a `<Page>` —
+		// detect that regression here.
+
+		// Arrange — boot composition.
+		EnsureComposition();
+
+		// Act — pull every resource-node-factory and every file-handler from the container.
+		var factories = AppComposition.Current.GetExports<IResourceNodeFactory>().ToList();
+		var handlers = AppComposition.Current.GetExports<IResourceFileHandler>().ToList();
+
+		// Assert — at least one of each is our BAML implementation.
+		factories.Should().ContainItemsAssignableTo<BamlResourceNodeFactory>();
+		handlers.Should().ContainItemsAssignableTo<BamlResourceFileHandler>();
+	}
+}
diff --git a/ILSpy.Tests/Resources/ResourceFactoryTests.cs b/ILSpy.Tests/Resources/ResourceFactoryTests.cs
index cb626d358..e857eb956 100644
--- a/ILSpy.Tests/Resources/ResourceFactoryTests.cs
+++ b/ILSpy.Tests/Resources/ResourceFactoryTests.cs
@@ -54,6 +54,7 @@ public class ResourceFactoryTests
 	[TestCase("config.xml")]
 	[TestCase("transform.xslt")]
 	[TestCase("Window.xaml")]
+	[TestCase("MainWindow.baml")]
 	[TestCase("logo.png")]
 	[TestCase("logo.gif")]
 	[TestCase("logo.bmp")]
diff --git a/ILSpy/ILSpy.csproj b/ILSpy/ILSpy.csproj
index e7006966c..76b1878ee 100644
--- a/ILSpy/ILSpy.csproj
+++ b/ILSpy/ILSpy.csproj
@@ -74,6 +74,7 @@
   <ItemGroup>
     <ProjectReference Include="..\ICSharpCode.ILSpyX\ICSharpCode.ILSpyX.csproj" />
     <ProjectReference Include="..\ICSharpCode.Decompiler\ICSharpCode.Decompiler.csproj" />
+    <ProjectReference Include="..\ICSharpCode.BamlDecompiler\ICSharpCode.BamlDecompiler.csproj" />
   </ItemGroup>
 
   <!-- The Debug Steps pane is a DEBUG-only diagnostic. The code-behind and viewmodel
diff --git a/ILSpy/Languages/CSharpLanguage.cs b/ILSpy/Languages/CSharpLanguage.cs
index 62f41ea22..66f1de3e3 100644
--- a/ILSpy/Languages/CSharpLanguage.cs
+++ b/ILSpy/Languages/CSharpLanguage.cs
@@ -338,7 +338,9 @@ namespace ILSpy.Languages
 			var targetDirectory = options.SaveAsProjectDirectory!;
 			var resolver = assembly.GetAssemblyResolver(loadOnDemand: options.DecompilerSettings.AutoLoadAssemblyReferences);
 			var debugInfo = assembly.GetDebugInfoOrNull();
-			var decompiler = new WholeProjectDecompiler(
+			var decompiler = new ResourceHandlerProjectDecompiler(
+				assembly,
+				options,
 				options.DecompilerSettings,
 				resolver,
 				projectWriter: null,
@@ -354,6 +356,67 @@ namespace ILSpy.Languages
 			return id;
 		}
 
+		/// <summary>
+		/// <see cref="WholeProjectDecompiler"/> subclass that delegates resource entries to
+		/// MEF-discovered <see cref="IResourceFileHandler"/> implementations. The first
+		/// handler whose <c>CanHandle</c> returns true wins; its emitted file plus any
+		/// partial-type info or extra MSBuild properties land in the produced .csproj.
+		/// Falls through to <see cref="WholeProjectDecompiler.WriteResourceToFile"/>'s
+		/// default "raw bytes as embedded resource" behaviour when no handler claims it.
+		/// </summary>
+		sealed class ResourceHandlerProjectDecompiler : WholeProjectDecompiler
+		{
+			readonly LoadedAssembly assembly;
+			readonly DecompilationOptions options;
+			static readonly IReadOnlyList<IResourceFileHandler> handlers = TryDiscoverHandlers();
+
+			public ResourceHandlerProjectDecompiler(
+				LoadedAssembly assembly,
+				DecompilationOptions options,
+				DecompilerSettings settings,
+				IAssemblyResolver resolver,
+				IProjectFileWriter? projectWriter,
+				AssemblyReferenceClassifier? assemblyReferenceClassifier,
+				ICSharpCode.Decompiler.DebugInfo.IDebugInfoProvider? debugInfoProvider)
+				: base(settings, resolver, projectWriter!, assemblyReferenceClassifier!, debugInfoProvider!)
+			{
+				this.assembly = assembly;
+				this.options = options;
+			}
+
+			protected override IEnumerable<ProjectItemInfo> WriteResourceToFile(string fileName, string resourceName, Stream entryStream)
+			{
+				var context = new ResourceFileHandlerContext(options);
+				foreach (var handler in handlers)
+				{
+					if (!handler.CanHandle(fileName, context))
+						continue;
+					entryStream.Position = 0;
+					fileName = handler.WriteResourceToFile(assembly, fileName, entryStream, context);
+					var item = new ProjectItemInfo(handler.EntryType, fileName) { PartialTypes = context.PartialTypes };
+					foreach (var (k, v) in context.AdditionalProperties)
+						item.AdditionalProperties.Add(k, v);
+					return new[] { item };
+				}
+				return base.WriteResourceToFile(fileName, resourceName, entryStream);
+			}
+
+			static IReadOnlyList<IResourceFileHandler> TryDiscoverHandlers()
+			{
+				try
+				{
+					return AppEnv.AppComposition.Current.GetExports<IResourceFileHandler>().ToArray();
+				}
+				catch
+				{
+					// Composition isn't available in tests that bypass the host (e.g. invoking
+					// DecompileAsProject directly with a self-built LoadedAssembly). Fall back
+					// to the raw-bytes behaviour from the base class.
+					return System.Array.Empty<IResourceFileHandler>();
+				}
+			}
+		}
+
 		static List<EntityHandle> CollectFieldsAndCtors(ITypeDefinition type, bool isStatic)
 		{
 			var members = new List<EntityHandle>();
diff --git a/ILSpy/Languages/IResourceFileHandler.cs b/ILSpy/Languages/IResourceFileHandler.cs
new file mode 100644
index 000000000..3c7fced83
--- /dev/null
+++ b/ILSpy/Languages/IResourceFileHandler.cs
@@ -0,0 +1,81 @@
+// Copyright (c) 2026 AlphaSierraPapa for the SharpDevelop Team
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this
+// software and associated documentation files (the "Software"), to deal in the Software
+// without restriction, including without limitation the rights to use, copy, modify, merge,
+// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
+// to whom the Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all copies or
+// substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
+// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+using System.Collections.Generic;
+using System.IO;
+
+using ICSharpCode.Decompiler;
+using ICSharpCode.ILSpyX;
+
+namespace ILSpy.Languages
+{
+	/// <summary>
+	/// Plug-in contract for converting a resource entry from its raw byte form into a
+	/// language-specific source file during project export. Implementations are MEF-discovered
+	/// via <c>[Export(typeof(IResourceFileHandler))]</c> and consulted by
+	/// <see cref="CSharpLanguage"/>'s project-export path; the first one to <see cref="CanHandle"/>
+	/// the resource wins. The handler returns the on-disk file name it emitted so the project
+	/// file picks the right MSBuild item group + Generator / SubType properties.
+	/// </summary>
+	public interface IResourceFileHandler
+	{
+		/// <summary>
+		/// MSBuild item type for the produced project entry — <c>"Page"</c> for BAML→XAML,
+		/// <c>"EmbeddedResource"</c> for the default raw fallback, etc.
+		/// </summary>
+		string EntryType { get; }
+
+		/// <summary>Returns true when this handler can process the named resource.</summary>
+		bool CanHandle(string name, ResourceFileHandlerContext context);
+
+		/// <summary>
+		/// Writes the decoded resource into the project directory (taken from
+		/// <see cref="ResourceFileHandlerContext.DecompilationOptions"/>) and returns the
+		/// resulting file name (relative to that directory). May add partial-type info to
+		/// <paramref name="context"/> for downstream WPF page x:Class binding.
+		/// </summary>
+		string WriteResourceToFile(LoadedAssembly assembly, string fileName, Stream stream, ResourceFileHandlerContext context);
+	}
+
+	/// <summary>
+	/// Per-project-export context shared across every <see cref="IResourceFileHandler"/>
+	/// invocation in a single export run. Collects partial-type info and additional MSBuild
+	/// properties; <see cref="CSharpLanguage"/>'s ILSpyWholeProjectDecompiler stitches them
+	/// into the produced .csproj.
+	/// </summary>
+	public class ResourceFileHandlerContext
+	{
+		readonly List<ICSharpCode.Decompiler.PartialTypeInfo> partialTypes = new();
+		internal List<ICSharpCode.Decompiler.PartialTypeInfo> PartialTypes => partialTypes;
+
+		readonly Dictionary<string, string> additionalProperties = new();
+		public Dictionary<string, string> AdditionalProperties => additionalProperties;
+
+		public DecompilationOptions DecompilationOptions { get; }
+
+		public ResourceFileHandlerContext(DecompilationOptions options)
+		{
+			this.DecompilationOptions = options;
+		}
+
+		public void AddPartialTypeInfo(ICSharpCode.Decompiler.PartialTypeInfo info)
+		{
+			this.PartialTypes.Add(info);
+		}
+	}
+}
diff --git a/ILSpy/TreeNodes/BamlResourceEntryNode.cs b/ILSpy/TreeNodes/BamlResourceEntryNode.cs
new file mode 100644
index 000000000..886d13dc9
--- /dev/null
+++ b/ILSpy/TreeNodes/BamlResourceEntryNode.cs
@@ -0,0 +1,80 @@
+// Copyright (c) 2026 AlphaSierraPapa for the SharpDevelop Team
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this
+// software and associated documentation files (the "Software"), to deal in the Software
+// without restriction, including without limitation the rights to use, copy, modify, merge,
+// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
+// to whom the Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all copies or
+// substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
+// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+using System;
+using System.IO;
+using System.Linq;
+
+using ICSharpCode.BamlDecompiler;
+using ICSharpCode.Decompiler;
+
+using ILSpy.Languages;
+using ILSpy.TextView;
+using ILSpy.TreeNodes;
+
+namespace ILSpy.Baml
+{
+	/// <summary>
+	/// Tree node for a single <c>.baml</c> resource entry inside a WPF/UWP assembly's
+	/// resource file. Selecting the node decompiles the BAML stream into XAML on a
+	/// background thread and emits the resulting XML into the editor (XML highlighting
+	/// kicks in via <c>SyntaxExtensionOverride</c>).
+	/// </summary>
+	public sealed class BamlResourceEntryNode : ResourceEntryNode
+	{
+		public BamlResourceEntryNode(string key, Func<Stream> openStream)
+			: base(key, openStream)
+		{
+		}
+
+		public override void Decompile(Language language, ITextOutput output, DecompilationOptions options)
+		{
+			try
+			{
+				LoadBaml(output, options);
+				// Surface the rendered XAML as XML in the editor so the highlighter kicks in
+				// and the foldings strategy collapses nested elements. The smart-output sink
+				// reads this override before falling back to the language's FileExtension.
+				if (output is AvaloniaEditTextOutput edit)
+					edit.SyntaxExtensionOverride = ".xml";
+			}
+			catch (Exception ex)
+			{
+				language.WriteCommentLine(output, "BAML decompilation failed:");
+				output.WriteLine(ex.ToString());
+			}
+		}
+
+		void LoadBaml(ITextOutput output, DecompilationOptions options)
+		{
+			var assemblyNode = this.Ancestors().OfType<AssemblyTreeNode>().First();
+			var assembly = assemblyNode.LoadedAssembly;
+			using var data = OpenStream();
+			var typeSystem = new BamlDecompilerTypeSystem(
+				assembly.GetMetadataFileOrNull()!,
+				assembly.GetAssemblyResolver());
+			var decompiler = new XamlDecompiler(typeSystem, new BamlDecompilerSettings {
+				ThrowOnAssemblyResolveErrors = options.DecompilerSettings.ThrowOnAssemblyResolveErrors,
+			}) {
+				CancellationToken = options.CancellationToken,
+			};
+			var result = decompiler.Decompile(data);
+			output.Write(result.Xaml.ToString());
+		}
+	}
+}
diff --git a/ILSpy/TreeNodes/BamlResourceNodeFactory.cs b/ILSpy/TreeNodes/BamlResourceNodeFactory.cs
new file mode 100644
index 000000000..fd6cf519e
--- /dev/null
+++ b/ILSpy/TreeNodes/BamlResourceNodeFactory.cs
@@ -0,0 +1,108 @@
+// Copyright (c) 2026 AlphaSierraPapa for the SharpDevelop Team
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this
+// software and associated documentation files (the "Software"), to deal in the Software
+// without restriction, including without limitation the rights to use, copy, modify, merge,
+// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
+// to whom the Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all copies or
+// substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
+// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+using System;
+using System.Composition;
+using System.IO;
+
+using ICSharpCode.BamlDecompiler;
+using ICSharpCode.Decompiler;
+using ICSharpCode.Decompiler.CSharp.ProjectDecompiler;
+using ICSharpCode.Decompiler.Metadata;
+using ICSharpCode.ILSpyX;
+using ICSharpCode.ILSpyX.Abstractions;
+
+using ILSpy.Languages;
+using ILSpy.TreeNodes;
+
+using IResourceFileHandler = ILSpy.Languages.IResourceFileHandler;
+using ResourceFileHandlerContext = ILSpy.Languages.ResourceFileHandlerContext;
+
+namespace ILSpy.Baml
+{
+	/// <summary>
+	/// Tree-node factory that claims <c>.baml</c> resource entries inside an embedded
+	/// <c>.resources</c> file and wraps them in a <see cref="BamlResourceEntryNode"/>.
+	/// Discovered by MEF via <see cref="ILSpyTreeNode.ResourceNodeFactories"/>.
+	/// </summary>
+	[Export(typeof(IResourceNodeFactory))]
+	[Shared]
+	public sealed class BamlResourceNodeFactory : IResourceNodeFactory
+	{
+		public ITreeNode? CreateNode(Resource resource)
+		{
+			if (resource.Name.EndsWith(".baml", StringComparison.OrdinalIgnoreCase))
+				return new BamlResourceEntryNode(resource.Name, () => resource.TryOpenStream() ?? Stream.Null);
+			return null;
+		}
+	}
+
+	/// <summary>
+	/// Project-export resource handler that intercepts <c>.baml</c> entries during
+	/// "Save Code" / project export, decompiles them to XAML, and writes them as
+	/// MSBuild <c>&lt;Page&gt;</c> items. The accompanying generated code-behind
+	/// partial-class members are surfaced via <see cref="PartialTypeInfo"/> so the
+	/// CSharp project decompiler emits matching <c>InitializeComponent</c> stubs.
+	/// </summary>
+	[Export(typeof(IResourceFileHandler))]
+	[Shared]
+	public sealed class BamlResourceFileHandler : IResourceFileHandler
+	{
+		public string EntryType => "Page";
+
+		public bool CanHandle(string name, ResourceFileHandlerContext context)
+			=> name.EndsWith(".baml", StringComparison.OrdinalIgnoreCase);
+
+		public string WriteResourceToFile(LoadedAssembly assembly, string fileName, Stream stream, ResourceFileHandlerContext context)
+		{
+			var typeSystem = new BamlDecompilerTypeSystem(
+				assembly.GetMetadataFileOrNull()!,
+				assembly.GetAssemblyResolver());
+			var decompiler = new XamlDecompiler(typeSystem, new BamlDecompilerSettings {
+				ThrowOnAssemblyResolveErrors = context.DecompilationOptions.DecompilerSettings.ThrowOnAssemblyResolveErrors,
+			}) {
+				CancellationToken = context.DecompilationOptions.CancellationToken,
+			};
+			var result = decompiler.Decompile(stream);
+			// If the BAML root names a CLR partial-class type, prefer the type's reflection name
+			// for the .xaml file so it lines up with the matching .xaml.cs the C# project writer
+			// emits. Otherwise just swap extensions on the existing resource name.
+			var typeDefinition = result.TypeName.HasValue
+				? typeSystem.MainModule.GetTypeDefinition(result.TypeName.Value.TopLevelTypeName)
+				: null;
+			if (typeDefinition != null)
+			{
+				fileName = WholeProjectDecompiler.SanitizeFileName(typeDefinition.ReflectionName + ".xaml");
+				var partialTypeInfo = new PartialTypeInfo(typeDefinition);
+				foreach (var member in result.GeneratedMembers)
+					partialTypeInfo.AddDeclaredMember(member);
+				context.AddPartialTypeInfo(partialTypeInfo);
+			}
+			else
+			{
+				fileName = Path.ChangeExtension(fileName, ".xaml");
+			}
+			context.AdditionalProperties.Add("Generator", "MSBuild:Compile");
+			context.AdditionalProperties.Add("SubType", "Designer");
+			var saveFileName = Path.Combine(context.DecompilationOptions.SaveAsProjectDirectory!, fileName);
+			Directory.CreateDirectory(Path.GetDirectoryName(saveFileName)!);
+			result.Xaml.Save(saveFileName);
+			return fileName;
+		}
+	}
+}