1 files changed, 111 insertions, 5 deletions

diff --git a/modules/mono/glue/Managed/Files/MarshalUtils.cs b/modules/mono/glue/Managed/Files/MarshalUtils.cs
index 7e72b0edb5..730a1e1585 100644
--- a/modules/mono/glue/Managed/Files/MarshalUtils.cs
+++ b/modules/mono/glue/Managed/Files/MarshalUtils.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Collections;
+using System.Collections.Generic;
 
 namespace Godot
 {
@@ -8,29 +9,113 @@ namespace Godot
 
     static class MarshalUtils
     {
+        /// <summary>
+        /// Returns <see langword="true"/> if the generic type definition of <paramref name="type"/>
+        /// is <see cref="Godot.Collections.Array{T}"/>; otherwise returns <see langword="false"/>.
+        /// </summary>
+        /// <exception cref="System.InvalidOperationException">
+        /// <paramref name="type"/> is not a generic type. That is, IsGenericType returns false.
+        /// </exception>
         static bool TypeIsGenericArray(Type type)
         {
             return type.GetGenericTypeDefinition() == typeof(Godot.Collections.Array<>);
         }
 
+        /// <summary>
+        /// Returns <see langword="true"/> if the generic type definition of <paramref name="type"/>
+        /// is <see cref="Godot.Collections.Dictionary{T}"/>; otherwise returns <see langword="false"/>.
+        /// </summary>
+        /// <exception cref="System.InvalidOperationException">
+        /// <paramref name="type"/> is not a generic type. That is, IsGenericType returns false.
+        /// </exception>
         static bool TypeIsGenericDictionary(Type type)
         {
             return type.GetGenericTypeDefinition() == typeof(Godot.Collections.Dictionary<,>);
         }
 
-        static void ArrayGetElementType(Type type, out Type elementType)
+        static void ArrayGetElementType(Type arrayType, out Type elementType)
         {
-            elementType = type.GetGenericArguments()[0];
+            elementType = arrayType.GetGenericArguments()[0];
         }
 
-        static void DictionaryGetKeyValueTypes(Type type, out Type keyType, out Type valueType)
+        static void DictionaryGetKeyValueTypes(Type dictionaryType, out Type keyType, out Type valueType)
         {
-            var genericArgs = type.GetGenericArguments();
-
+            var genericArgs = dictionaryType.GetGenericArguments();
             keyType = genericArgs[0];
             valueType = genericArgs[1];
         }
 
+        static bool GenericIEnumerableIsAssignableFromType(Type type, out Type elementType)
+        {
+            if (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(IEnumerable<>))
+            {
+                elementType = type.GetGenericArguments()[0];
+                return true;
+            }
+
+            foreach (var interfaceType in type.GetInterfaces())
+            {
+                if (interfaceType.IsGenericType && interfaceType.GetGenericTypeDefinition() == typeof(IEnumerable<>))
+                {
+                    elementType = interfaceType.GetGenericArguments()[0];
+                    return true;
+                }
+            }
+
+            Type baseType = type.BaseType;
+
+            if (baseType == null)
+            {
+                elementType = null;
+                return false;
+            }
+
+            return GenericIEnumerableIsAssignableFromType(baseType, out elementType);
+        }
+
+        static bool GenericIDictionaryIsAssignableFromType(Type type, out Type keyType, out Type valueType)
+        {
+            if (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(IDictionary<,>))
+            {
+                var genericArgs = type.GetGenericArguments();
+                keyType = genericArgs[0];
+                valueType = genericArgs[1];
+                return true;
+            }
+
+            foreach (var interfaceType in type.GetInterfaces())
+            {
+                if (interfaceType.IsGenericType && interfaceType.GetGenericTypeDefinition() == typeof(IDictionary<,>))
+                {
+                    var genericArgs = interfaceType.GetGenericArguments();
+                    keyType = genericArgs[0];
+                    valueType = genericArgs[1];
+                    return true;
+                }
+            }
+
+            Type baseType = type.BaseType;
+
+            if (baseType == null)
+            {
+                keyType = null;
+                valueType = null;
+                return false;
+            }
+
+            return GenericIDictionaryIsAssignableFromType(baseType, out keyType, out valueType);
+        }
+
+        static Type MakeGenericArrayType(Type elemType)
+        {
+            return typeof(Godot.Collections.Array<>).MakeGenericType(elemType);
+        }
+
+        static Type MakeGenericDictionaryType(Type keyType, Type valueType)
+        {
+            return typeof(Godot.Collections.Dictionary<,>).MakeGenericType(keyType, valueType);
+        }
+
         // TODO Add support for IEnumerable<T> and IDictionary<TKey, TValue>
         // TODO: EnumerableToArray and IDictionaryToDictionary can be optimized
 
@@ -64,5 +149,26 @@ namespace Godot
                 Dictionary.godot_icall_Dictionary_Add(godotDictionaryPtr, entry.Key, entry.Value);
             }
         }
+
+        internal static void GenericIDictionaryToDictionary(object dictionary, IntPtr godotDictionaryPtr)
+        {
+#if DEBUG
+            if (!GenericIDictionaryIsAssignableFromType(dictionary.GetType()))
+                throw new InvalidOperationException("The type does not implement IDictionary<,>");
+#endif
+
+            // TODO: Can we optimize this?
+
+            var keys = ((IEnumerable)dictionary.GetType().GetProperty("Keys").GetValue(dictionary)).GetEnumerator();
+            var values = ((IEnumerable)dictionary.GetType().GetProperty("Values").GetValue(dictionary)).GetEnumerator();
+
+            while (keys.MoveNext() && values.MoveNext())
+            {
+                object key = keys.Current;
+                object value = values.Current;
+
+                Dictionary.godot_icall_Dictionary_Add(godotDictionaryPtr, key, value);
+            }
+        }
     }
 }