[RGen] Add the new added methods to smart enums. (#22250)

In order to simplify the BindAs/BindFrom code, new methods were added to
the smart enums generated by bgen. We have to do the same in rgen.

---------

Co-authored-by: GitHub Actions Autoformatter <[email protected]>

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

@@ -95,6 +95,17 @@ void EmitExtensionMethods (TabbedWriter<StringWriter> classBlock, in Binding bin
 			getValueBlock.WriteLine (
 				"throw new NotSupportedException ($\"The constant {constant} has no associated enum value on this platform.\");");
 		}
+		classBlock.WriteLine ();
+
+		// get value from a handle, this is a helper method used in the BindAs bindings.
+		using (var getValueFromHandle =
+			   classBlock.CreateBlock ($"public static {binding.Name} GetValueFromHandle (NativeHandle handle)",
+				   true)) {
+			getValueFromHandle.WriteRaw (
+@"using var str = Runtime.GetNSObject<NSString> (handle)!;
+return GetValue (str);
+");
+		}
 
 		classBlock.WriteLine ();
 		// To ConstantArray

tests/cecil-tests/Documentation.KnownFailures.txt

@@ -23150,6 +23150,7 @@ M:AVFoundation.AVCapturePhotoSettingsThumbnailFormat.#ctor
 M:AVFoundation.AVCapturePhotoSettingsThumbnailFormat.#ctor(Foundation.NSDictionary)
 M:AVFoundation.AVCaptureReactionTypeExtensions.GetConstant(AVFoundation.AVCaptureReactionType)
 M:AVFoundation.AVCaptureReactionTypeExtensions.GetValue(Foundation.NSString)
+M:AVFoundation.AVCaptureReactionTypeExtensions.GetValueFromHandle(ObjCRuntime.NativeHandle)
 M:AVFoundation.AVCaptureSessionRuntimeErrorEventArgs.#ctor(Foundation.NSNotification)
 M:AVFoundation.AVCaptureStillImageOutput.CaptureStillImageTaskAsync(AVFoundation.AVCaptureConnection)
 M:AVFoundation.AVCaptureVideoDataOutput.GetRecommendedVideoSettings(AVFoundation.AVVideoCodecType,AVFoundation.AVFileTypes,Foundation.NSUrl)

tests/rgen/Microsoft.Macios.Generator.Tests/SmartEnum/Data/ExpectedAVCaptureDeviceTypeEnum.cs

@@ -196,6 +196,12 @@ public static AVCaptureDeviceType GetValue (NSString constant)
 		throw new NotSupportedException ($"The constant {constant} has no associated enum value on this platform.");
 	}
 
+	public static AVCaptureDeviceType GetValueFromHandle (NativeHandle handle)
+	{
+		using var str = Runtime.GetNSObject<NSString> (handle)!;
+		return GetValue (str);
+	}
+
 	internal static NSString?[]? ToConstantArray (this AVCaptureDeviceType[]? values)
 	{
 		if (values is null)

tests/rgen/Microsoft.Macios.Generator.Tests/SmartEnum/Data/ExpectedAVCaptureSystemPressureLevel.cs

@@ -106,6 +106,12 @@ public static AVCaptureSystemPressureLevel GetValue (NSString constant)
 		throw new NotSupportedException ($"The constant {constant} has no associated enum value on this platform.");
 	}
 
+	public static AVCaptureSystemPressureLevel GetValueFromHandle (NativeHandle handle)
+	{
+		using var str = Runtime.GetNSObject<NSString> (handle)!;
+		return GetValue (str);
+	}
+
 	internal static NSString?[]? ToConstantArray (this AVCaptureSystemPressureLevel[]? values)
 	{
 		if (values is null)

tests/rgen/Microsoft.Macios.Generator.Tests/SmartEnum/Data/ExpectedCustomLibraryEnum.cs

@@ -77,6 +77,12 @@ public static CustomLibraryEnum GetValue (NSString constant)
 		throw new NotSupportedException ($"The constant {constant} has no associated enum value on this platform.");
 	}
 
+	public static CustomLibraryEnum GetValueFromHandle (NativeHandle handle)
+	{
+		using var str = Runtime.GetNSObject<NSString> (handle)!;
+		return GetValue (str);
+	}
+
 	internal static NSString?[]? ToConstantArray (this CustomLibraryEnum[]? values)
 	{
 		if (values is null)

tests/rgen/Microsoft.Macios.Generator.Tests/SmartEnum/Data/ExpectedCustomLibraryEnumInternal.cs

@@ -77,6 +77,12 @@ public static CustomLibraryEnumInternal GetValue (NSString constant)
 		throw new NotSupportedException ($"The constant {constant} has no associated enum value on this platform.");
 	}
 
+	public static CustomLibraryEnumInternal GetValueFromHandle (NativeHandle handle)
+	{
+		using var str = Runtime.GetNSObject<NSString> (handle)!;
+		return GetValue (str);
+	}
+
 	internal static NSString?[]? ToConstantArray (this CustomLibraryEnumInternal[]? values)
 	{
 		if (values is null)

tests/rgen/Microsoft.Macios.Generator.Tests/SmartEnum/Data/ExpectedMacOSAVMediaCharacteristics.cs

@@ -359,6 +359,12 @@ public static AVMediaCharacteristics GetValue (NSString constant)
 		throw new NotSupportedException ($"The constant {constant} has no associated enum value on this platform.");
 	}
 
+	public static AVMediaCharacteristics GetValueFromHandle (NativeHandle handle)
+	{
+		using var str = Runtime.GetNSObject<NSString> (handle)!;
+		return GetValue (str);
+	}
+
 	internal static NSString?[]? ToConstantArray (this AVMediaCharacteristics[]? values)
 	{
 		if (values is null)

tests/rgen/Microsoft.Macios.Generator.Tests/SmartEnum/Data/ExpectediOSAVMediaCharacteristics.cs

@@ -378,6 +378,12 @@ public static AVMediaCharacteristics GetValue (NSString constant)
 		throw new NotSupportedException ($"The constant {constant} has no associated enum value on this platform.");
 	}
 
+	public static AVMediaCharacteristics GetValueFromHandle (NativeHandle handle)
+	{
+		using var str = Runtime.GetNSObject<NSString> (handle)!;
+		return GetValue (str);
+	}
+
 	internal static NSString?[]? ToConstantArray (this AVMediaCharacteristics[]? values)
 	{
 		if (values is null)