Avoid Reflection

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

@@ -8,34 +8,7 @@ public class BoxedWrapper
 {
     public static object WrapHandle(IntPtr handle, bool ownsHandle, Type gtype)
     {
-        System.Type trueType = TypeDictionary.GetSystemType(gtype);
-
-        if (handle == IntPtr.Zero)
-            throw new NullReferenceException($"Failed to wrap handle as type <{trueType}>. Null handle passed to WrapHandle.");
-
-        // Get constructor for the true type
-        var ctr = GetBoxedConstructor(trueType);
-
-        if (ctr is null)
-            throw new Exception($"Type {trueType} does not define an IntPtr constructor. This could mean improperly defined bindings");
-
-        var result = ctr.Invoke(new object[] { handle, ownsHandle });
-
-        if (result == null)
-            throw new Exception($"Type {trueType}'s factory method returned a null object. This could mean improperly defined bindings");
-
-        return result;
-    }
-
-    private static ConstructorInfo? GetBoxedConstructor(System.Type type)
-    {
-        // Create using 'IntPtr, ownsHandle' constructor
-        ConstructorInfo? ctor = type.GetConstructor(
-            System.Reflection.BindingFlags.NonPublic
-            | System.Reflection.BindingFlags.Public
-            | System.Reflection.BindingFlags.Instance,
-            null, new[] { typeof(IntPtr), typeof(bool) }, null
-        );
-        return ctor;
+        //TODO: REMOVE BOXED WRAPPER
+        return InstanceFactory.Create(handle, ownsHandle);
     }
 }

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 +1,47 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Runtime.CompilerServices;
+
+namespace GObject.Internal;
+
+/// <summary>
+/// Creates new instances of classes and records
+/// </summary>
+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");
+
+        //TODO: What happens if type is not registered. Original TypeDirectory had a fallback until a parent was found?!
+
+        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 gclass = Unsafe.AsRef<TypeInstanceData>((void*) handle).GClass;
+        var gtype = Unsafe.AsRef<TypeClassData>((void*) gclass).GType;
+
+        if (gtype == 0)
+            throw new Exception("Could not retrieve type from class struct - is the struct valid?");
+
+        return new Type(gtype);
+    }
+}

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
@@ -78,17 +57,6 @@ public static class ObjectWrapper
         return (T) ctor.Invoke(new object[] { handle, ownedRef });
     }
 
-    private static unsafe Type GetTypeFromInstance(IntPtr handle)
-    {
-        var gclass = Unsafe.AsRef<TypeInstanceData>((void*) handle).GClass;
-        var gtype = Unsafe.AsRef<TypeClassData>((void*) gclass).GType;
-
-        if (gtype == 0)
-            throw new Exception("Could not retrieve type from class struct - is the struct valid?");
-
-        return new Type(gtype);
-    }
-
     private static ConstructorInfo? GetObjectConstructor(System.Type type)
     {
         // Create using 'IntPtr' constructor

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

@@ -47,7 +47,6 @@ public enum BasicType
 public static class TypeDictionary
 {
     private static readonly Dictionary<System.Type, Type> _systemTypeDict = new();
-    private static readonly Dictionary<Type, System.Type> _reverseTypeDict = new();
 
     /// <summary>
     /// Add a new mapping of (System.Type, GObject.Type) to the type dictionary. 
@@ -63,7 +62,6 @@ public static void Add(System.Type systemType, Type type)
         );
 
         _systemTypeDict[systemType] = type;
-        _reverseTypeDict[type] = systemType;
     }
 
     /// <summary>
@@ -87,39 +85,7 @@ internal static Type GetGType(System.Type type)
         return _systemTypeDict[type];
     }
 
-    /// <summary>
-    /// For a given gtype, retrieve the corresponding managed type.  
-    /// </summary>
-    /// <param name="gtype">A type from the GType type system</param>
-    /// <returns>The equivalent managed type</returns>
-    internal static System.Type GetSystemType(Type gtype)
-    {
-        if (_reverseTypeDict.TryGetValue(gtype, out System.Type? sysType))
-            return sysType;
-
-        // If gtype is not in the type dictionary, walk up the
-        // tree until we find a type that is. As all objects are
-        // descended from GObject, we will eventually find a parent
-        // type that is registered.
-
-        while (!_reverseTypeDict.TryGetValue(gtype, out sysType))
-        {
-            gtype = new Type(Functions.TypeParent(gtype.Value));
-            if (gtype.Value == (nuint) BasicType.Invalid ||
-                gtype.Value == (nuint) BasicType.None)
-                throw new Exception("Could not retrieve parent type - is the typeid valid?");
-        }
-
-        // Store for future lookups
-        _reverseTypeDict[gtype] = sysType;
-
-        return sysType;
-    }
-
     // These may be unneeded - keep for now 
-    internal static bool ContainsGType(Type gtype)
-        => _reverseTypeDict.ContainsKey(gtype);
-
     internal static bool ContainsSystemType(System.Type type)
         => _systemTypeDict.ContainsKey(type);
 }