Avoid Reflection

src/Libs/GObject-2.0/Internal/BoxedWrapper.cs

@@ -8,6 +8,8 @@ public class BoxedWrapper
 {
     public static object WrapHandle(IntPtr handle, bool ownsHandle, Type gtype)
     {
+        return InstanceFactory.Create(handle, ownsHandle);
+
         System.Type trueType = TypeDictionary.GetSystemType(gtype);
 
         if (handle == IntPtr.Zero)

src/Libs/GObject-2.0/Internal/DemoTypeRegistration.cs

@@ -0,0 +1,27 @@
+using System;
+using System.Diagnostics;
+using System.Linq;
+using System.Runtime.InteropServices;
+
+namespace GObject.Internal;
+
+internal class DemoTypeRegistration
+{
+    internal static void RegisterTypes()
+    {
+        Register<GObject.Binding>(Binding.GetGType, (ptr, ownedRef) => new GObject.Binding(ptr, ownedRef), OSPlatform.Linux, OSPlatform.OSX, OSPlatform.Windows);
+    }
+
+    private static void Register<T>(Func<nuint> getType, Func<IntPtr, bool, GObject.Object> factory, params OSPlatform[] supportedPlatforms) where T : class
+    {
+        try
+        {
+            if (supportedPlatforms.Any(RuntimeInformation.IsOSPlatform))
+                InstanceFactory.AddFactoryForType(getType(), factory);
+        }
+        catch (System.Exception e)
+        {
+            Debug.WriteLine($"Could not register type '{nameof(T)}': {e.Message}");
+        }
+    }
+}

src/Libs/GObject-2.0/Internal/InstanceFactory.cs

@@ -0,0 +1,48 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+namespace GObject.Internal;
+
+internal class InstanceFactory
+{
+    private static readonly Dictionary<Type, Func<IntPtr, bool, object>> Factories = new();
+
+    public static object Create(IntPtr handle, bool ownedRef)
+    {
+        var gtype = GetTypeFromInstance(handle);
+
+        Debug.Assert(
+            condition: Functions.TypeName(gtype.Value).ConvertToString() == Functions.TypeNameFromInstance(new TypeInstanceUnownedHandle(handle)).ConvertToString(),
+            message: "GType name of instance and class do not match"
+        );
+
+        if (!Factories.TryGetValue(gtype, out var handleFactory))
+            throw new Exception("Cant create handle for unknown type");
+
+        return handleFactory(handle, ownedRef);
+    }
+
+    public static void AddFactoryForType(Type type, Func<IntPtr, bool, GObject.Object> factory)
+    {
+        Factories[type] = factory;
+    }
+
+    private static unsafe Type GetTypeFromInstance(IntPtr handle)
+    {
+        var klassPtr = Unsafe.AsRef<TypeInstanceData>((void*) handle).GClass;
+        var typeId = Unsafe.AsRef<TypeClassData>((void*) klassPtr).GType;
+
+
+        TypeInstanceData instance = Marshal.PtrToStructure<TypeInstanceData>(handle);
+        TypeClassData klass = Marshal.PtrToStructure<TypeClassData>(instance.GClass);
+        var typeid = klass.GType;
+
+        if (typeid == 0)
+            throw new Exception("Could not retrieve type from class struct - is the struct valid?");
+
+        return new Type(typeid);
+    }
+}

src/Libs/GObject-2.0/Internal/ObjectWrapper.cs

@@ -8,43 +8,22 @@ namespace GObject.Internal;
 
 public static class ObjectWrapper
 {
-    public static T? WrapNullableHandle<T>(IntPtr handle, bool ownedRef) where T : class, IHandle
+    public static T? WrapNullableHandle<T>(IntPtr handle, bool ownedRef) where T : GObject.Object, IHandle
     {
         return handle == IntPtr.Zero
             ? null
             : WrapHandle<T>(handle, ownedRef);
     }
 
-    public static T WrapHandle<T>(IntPtr handle, bool ownedRef) where T : class, IHandle
+    public static T WrapHandle<T>(IntPtr handle, bool ownedRef) where T : GObject.Object, IHandle
     {
-        Debug.Assert(
-            condition: typeof(T).IsClass && typeof(T).IsAssignableTo(typeof(GObject.Object)),
-            message: "Type 'T' must be a GObject-based class"
-        );
-
         if (handle == IntPtr.Zero)
             throw new NullReferenceException($"Failed to wrap handle as type <{typeof(T).FullName}>. Null handle passed to WrapHandle.");
 
         if (ObjectMapper.TryGetObject(handle, out T? obj))
             return obj;
 
-        //In case of classes prefer the type reported by the gobject type system over
-        //the expected type as often an API returns a less derived class in it's public
-        //API then the actual one.
-        Type gtype = GetTypeFromInstance(handle);
-
-        Debug.Assert(
-            condition: Functions.TypeName(gtype.Value).ConvertToString() == Functions.TypeNameFromInstance(new TypeInstanceUnownedHandle(handle)).ConvertToString(),
-            message: "GType name of instance and class do not match"
-        );
-
-        System.Type trueType = TypeDictionary.GetSystemType(gtype);
-        ConstructorInfo? ctor = GetObjectConstructor(trueType);
-
-        if (ctor == null)
-            throw new Exception($"Type {typeof(T).FullName} does not define an IntPtr constructor. This could mean improperly defined bindings");
-
-        return (T) ctor.Invoke(new object[] { handle, ownedRef });
+        return (T) InstanceFactory.Create(handle, ownedRef);
     }
 
     public static T? WrapNullableInterfaceHandle<T>(IntPtr handle, bool ownedRef) where T : class, IHandle
@@ -78,18 +57,6 @@ public static T WrapInterfaceHandle<T>(IntPtr handle, bool ownedRef) where T : c
         return (T) ctor.Invoke(new object[] { handle, ownedRef });
     }
 
-    private static Type GetTypeFromInstance(IntPtr handle)
-    {
-        TypeInstanceData instance = Marshal.PtrToStructure<TypeInstanceData>(handle);
-        TypeClassData klass = Marshal.PtrToStructure<TypeClassData>(instance.GClass);
-        var typeid = klass.GType;
-
-        if (typeid == 0)
-            throw new Exception("Could not retrieve type from class struct - is the struct valid?");
-
-        return new Type(typeid);
-    }
-
     private static ConstructorInfo? GetObjectConstructor(System.Type type)
     {
         // Create using 'IntPtr' constructor