[RGen] Implement the basic Wrapper implementation. (#23462)

Add the Protocol Wrapper class definition. Do not generate methods or
properties yet, do that in follow up PRs because we need changes in the
property and method emitters.

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: GitHub Actions Autoformatter <github-actions-autoformatter@xamarin.com>

Author: 3 people

src/rgen/Microsoft.Macios.Generator/Emitters/EmitterFactory.cs

@@ -14,7 +14,7 @@ static class EmitterFactory {
 	static readonly Dictionary<BindingType, ICodeEmitter> emitters = new () {
 		{ BindingType.Class, new ClassEmitter () },
 		{ BindingType.SmartEnum, new EnumEmitter () },
-		{ BindingType.Protocol, new ProtocolEmitter () },
+		{ BindingType.Protocol, new ProtocolAndModelEmitter () },
 		{ BindingType.Category, new CategoryEmitter () },
 		{ BindingType.StrongDictionary, new StrongDictionaryEmitter () },
 		{ BindingType.StrongDictionaryKeys, new StrongDictionaryKeysEmitter () }

src/rgen/Microsoft.Macios.Generator/Emitters/ProtocolAndModelEmitter.cs

@@ -0,0 +1,54 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Diagnostics.CodeAnalysis;
+using Microsoft.CodeAnalysis;
+using Microsoft.Macios.Generator.Context;
+using Microsoft.Macios.Generator.DataModel;
+
+namespace Microsoft.Macios.Generator.Emitters;
+
+/// <summary>
+/// An emitter that combines the functionality of <see cref="ProtocolEmitter"/> and <see cref="ProtocolWrapperEmitter"/>
+/// to emit both the protocol interface and its corresponding wrapper class.
+/// </summary>
+class ProtocolAndModelEmitter : ICodeEmitter {
+	readonly ProtocolEmitter protocolEmitter = new ();
+	readonly ProtocolWrapperEmitter protocolWrapperEmitter = new ();
+
+	/// <inheritdoc />
+	public string GetSymbolName (in Binding binding) => protocolEmitter.GetSymbolName (binding);
+
+	/// <inheritdoc />
+	public IEnumerable<string> UsingStatements {
+		get {
+			foreach (var ns in protocolEmitter.UsingStatements) {
+				yield return ns;
+			}
+			foreach (var ns in protocolWrapperEmitter.UsingStatements) {
+				yield return ns;
+			}
+		}
+	}
+
+	/// <inheritdoc />
+	public bool TryEmit (in BindingContext bindingContext, [NotNullWhen (false)] out ImmutableArray<Diagnostic>? diagnostics)
+	{
+		// try to emit the protocol first
+		if (!protocolEmitter.TryEmit (bindingContext, out diagnostics)) {
+			return false;
+		}
+
+		// add space and add the wrapper emitter
+		bindingContext.Builder.WriteLine ();
+
+		if (!protocolWrapperEmitter.TryEmit (bindingContext, out diagnostics)) {
+			return false;
+		}
+
+		return true;
+	}
+
+}

src/rgen/Microsoft.Macios.Generator/Emitters/ProtocolWrapperEmitter.cs

@@ -0,0 +1,93 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Diagnostics.CodeAnalysis;
+using System.IO;
+using System.Linq;
+using Microsoft.CodeAnalysis;
+using Microsoft.Macios.Generator.Attributes;
+using Microsoft.Macios.Generator.Context;
+using Microsoft.Macios.Generator.DataModel;
+using Microsoft.Macios.Generator.IO;
+using ObjCBindings;
+
+namespace Microsoft.Macios.Generator.Emitters;
+
+/// <summary>
+/// Emits the wrapper class for a protocol.
+/// </summary>
+class ProtocolWrapperEmitter : ICodeEmitter {
+	/// <inheritdoc />
+	public string GetSymbolName (in Binding binding) => Nomenclator.GetProtocolWrapperName (binding.Name);
+
+	/// <inheritdoc />
+	public IEnumerable<string> UsingStatements { get; } = [];
+
+	/// <summary>
+	/// Emits the default constructors for the protocol wrapper class.
+	/// </summary>
+	/// <param name="bindingContext">The binding context.</param>
+	/// <param name="classBlock">The writer for the class block.</param>
+	void EmitDefaultConstructors (in BindingContext bindingContext, TabbedWriter<StringWriter> classBlock)
+	{
+		classBlock.WriteLine ("// Implement default constructor");
+		classBlock.WriteLine ();
+	}
+
+	/// <summary>
+	/// Emits the properties for the protocol wrapper class.
+	/// </summary>
+	/// <param name="context">The binding context.</param>
+	/// <param name="classBlock">The writer for the class block.</param>
+	void EmitProperties (in BindingContext context, TabbedWriter<StringWriter> classBlock)
+	{
+		var allProperties = context.Changes.Properties
+			.Concat (context.Changes.ParentProtocolProperties)
+			.OrderBy (p => p.Name);
+
+		foreach (var property in allProperties) {
+			classBlock.WriteLine ($"// Implement property: {property.Name}");
+			classBlock.WriteLine ();
+		}
+	}
+
+	/// <summary>
+	/// Emits the methods for the protocol wrapper class.
+	/// </summary>
+	/// <param name="context">The binding context.</param>
+	/// <param name="classBlock">The writer for the class block.</param>
+	void EmitMethods (in BindingContext context, TabbedWriter<StringWriter> classBlock)
+	{
+		var allMethods = context.Changes.Methods
+			.Concat (context.Changes.ParentProtocolMethods)
+			.OrderBy (m => m.Name);
+
+		foreach (var method in allMethods) {
+			classBlock.WriteLine ($"// Implement method: {method.Name}");
+			classBlock.WriteLine ();
+		}
+	}
+
+	/// <inheritdoc />
+	public bool TryEmit (in BindingContext bindingContext, [NotNullWhen (false)] out ImmutableArray<Diagnostic>? diagnostics)
+	{
+		diagnostics = null;
+		var bindingData = (BindingTypeData<Protocol>) bindingContext.Changes.BindingInfo;
+		var protocolName = bindingData.Name ?? bindingContext.Changes.Name [1..];
+		var wrapperName = Nomenclator.GetProtocolWrapperName (protocolName);
+
+		// we do not emit outer classes for protocol wrappers
+		using (var classBlock = bindingContext.Builder.CreateBlock (
+				   $"internal unsafe sealed class {wrapperName} : BaseWrapper, {bindingContext.Changes.Name}",
+				   true)) {
+			EmitDefaultConstructors (bindingContext, classBlock);
+			EmitProperties (bindingContext, classBlock);
+			EmitMethods (bindingContext, classBlock);
+		}
+
+		return true;
+	}
+
+}

tests/rgen/Microsoft.Macios.Generator.Tests/Emitters/EmitterFactoryTests.cs

@@ -145,7 +145,7 @@ public interface ITestInterface {
 ";
 		var changes = CreateSymbol<InterfaceDeclarationSyntax> (platform, inputText);
 		Assert.True (EmitterFactory.TryCreate (changes, out var emitter));
-		Assert.IsType<ProtocolEmitter> (emitter);
+		Assert.IsType<ProtocolAndModelEmitter> (emitter);
 		Assert.True (EmitterFactory.TryCreate (changes, out var secondEmitter));
 		Assert.Same (emitter, secondEmitter);
 	}

tests/rgen/Microsoft.Macios.Generator.Tests/Protocols/Data/ExpectedIAVAudio3DMixing.cs

@@ -346,3 +346,23 @@ internal static void _SetSourceMode (this IAVAudio3DMixing self, global::AVFound
 		set => _SetSourceMode (this, value);
 	}
 }
+
+internal unsafe sealed class AVAudio3DMixingWrapper : BaseWrapper, IAVAudio3DMixing
+{
+	// Implement default constructor
+
+	// Implement property: Obstruction
+
+	// Implement property: Occlusion
+
+	// Implement property: PointSourceInHeadMode
+
+	// Implement property: Rate
+
+	// Implement property: RenderingAlgorithm
+
+	// Implement property: ReverbBlend
+
+	// Implement property: SourceMode
+
+}

tests/rgen/Microsoft.Macios.Generator.Tests/Protocols/Data/ExpectedIAVAudioMixing.cs

@@ -97,3 +97,27 @@ public virtual partial float Volume
 		throw new global::Foundation.You_Should_Not_Call_base_In_This_Method ();
 	}
 }
+
+internal unsafe sealed class AVAudioMixingWrapper : BaseWrapper, IAVAudioMixing
+{
+	// Implement default constructor
+
+	// Implement property: Obstruction
+
+	// Implement property: Occlusion
+
+	// Implement property: PointSourceInHeadMode
+
+	// Implement property: Rate
+
+	// Implement property: RenderingAlgorithm
+
+	// Implement property: ReverbBlend
+
+	// Implement property: SourceMode
+
+	// Implement property: Volume
+
+	// Implement method: DestinationForMixer
+
+}

tests/rgen/Microsoft.Macios.Generator.Tests/Protocols/Data/IAVAudioMixing.cs

@@ -13,7 +13,36 @@ namespace Microsoft.Macios.Generator.Tests.Protocols.Data;
 [SupportedOSPlatform ("macos")]
 [SupportedOSPlatform ("maccatalyst13.1")]
 [BindingType<Protocol>]
-public partial interface IAVAudioMixing {
+public interface IAVAudio3DMixing {
+
+	[Export<Property> ("renderingAlgorithm")]
+	public virtual partial AVAudio3DMixingRenderingAlgorithm RenderingAlgorithm { get; set; }
+
+	[Export<Property> ("rate")]
+	public virtual partial float Rate { get; set; }
+
+	[Export<Property> ("reverbBlend")]
+	public virtual partial float ReverbBlend { get; set; }
+
+	[Export<Property> ("obstruction")]
+	public virtual partial float Obstruction { get; set; }
+
+	[Export<Property> ("occlusion")]
+	public virtual partial float Occlusion { get; set; }
+
+	[Export<Property> ("sourceMode", ArgumentSemantic.Assign)]
+	public virtual partial AVAudio3DMixingSourceMode SourceMode { get; set; }
+
+	[Export<Property> ("pointSourceInHeadMode", ArgumentSemantic.Assign)]
+	public virtual partial AVAudio3DMixingPointSourceInHeadMode PointSourceInHeadMode { get; set; }
+}
+
+[SupportedOSPlatform ("ios")]
+[SupportedOSPlatform ("tvos")]
+[SupportedOSPlatform ("macos")]
+[SupportedOSPlatform ("maccatalyst13.1")]
+[BindingType<Protocol>]
+public partial interface IAVAudioMixing : IAVAudio3DMixing {
 
 	[Export<Method> ("destinationForMixer:bus:")]
 	public virtual partial AVAudioMixingDestination? DestinationForMixer (AVAudioNode mixer, nuint bus);

tests/rgen/Microsoft.Macios.Generator.Tests/Protocols/ProtocolGenerationTests.cs

@@ -19,9 +19,9 @@ public class TestDataGenerator : BaseTestDataGenerator, IEnumerable<object []> {
 			(ApplePlatform.MacOSX, "IAVAudio3DMixing", "IAVAudio3DMixing.cs", "ExpectedIAVAudio3DMixing.cs", null),
 
 			(ApplePlatform.iOS, "IAVAudioMixing", "IAVAudioMixing.cs", "ExpectedIAVAudioMixing.cs", null),
-			(ApplePlatform.TVOS, "IAVAudio3DMixing", "IAVAudio3DMixing.cs", "ExpectedIAVAudio3DMixing.cs", null),
-			(ApplePlatform.MacCatalyst, "IAVAudio3DMixing", "IAVAudio3DMixing.cs", "ExpectedIAVAudio3DMixing.cs", null),
-			(ApplePlatform.MacOSX, "IAVAudio3DMixing", "IAVAudio3DMixing.cs", "ExpectedIAVAudio3DMixing.cs", null),
+			(ApplePlatform.TVOS, "IAVAudioMixing", "IAVAudioMixing.cs", "ExpectedIAVAudioMixing.cs", null),
+			(ApplePlatform.MacCatalyst, "IAVAudioMixing", "IAVAudioMixing.cs", "ExpectedIAVAudioMixing.cs", null),
+			(ApplePlatform.MacOSX, "IAVAudioMixing", "IAVAudioMixing.cs", "ExpectedIAVAudioMixing.cs", null),
 		};
 
 		public IEnumerator<object []> GetEnumerator ()