Basic script responsible for duplicating [SerializeReference]-based fields [WIP]

Author: arimger

Assets/Editor Toolbox/Editor/Internal/CopySerializeReferenceUtility.cs

@@ -0,0 +1,53 @@
+using UnityEditor;
+using UnityEngine;
+
+namespace Toolbox.Editor.Internal
+{
+    [InitializeOnLoad]
+    public static class CopySerializeReferenceUtility
+    {
+        static CopySerializeReferenceUtility()
+        {
+            propertyToCopy = null;
+            EditorApplication.contextualPropertyMenu -= OnContextMenuOpening;
+            EditorApplication.contextualPropertyMenu += OnContextMenuOpening;
+        }
+
+        private static SerializedProperty propertyToCopy;
+
+        private static void OnContextMenuOpening(GenericMenu menu, SerializedProperty property)
+        {
+            if (property.propertyType != SerializedPropertyType.ManagedReference || 
+                !PropertyUtility.IsSerializableArrayElement(property))
+            {
+                return;
+            }
+
+            menu.AddItem(new GUIContent("Copy Reference"), false, () =>
+            {
+                propertyToCopy = property;
+            });
+            menu.AddItem(new GUIContent("Duplicate Reference"), false, () =>
+            {
+                var parent = property.GetParent();
+                parent.arraySize++;
+                parent.serializedObject.ApplyModifiedProperties();
+                var newProperty = parent.GetArrayElementAtIndex(parent.arraySize - 1); 
+            });
+            if (propertyToCopy != null)
+            {
+                menu.AddItem(new GUIContent("Paste Reference"), false, () =>
+                {
+                    property.serializedObject.Update();
+                    //property.managedReferenceValue = null;
+                    property.serializedObject.ApplyModifiedProperties();
+                    propertyToCopy = null;
+                });
+            }
+            else
+            {
+                menu.AddDisabledItem(new GUIContent("Paste Reference"));
+            }
+        }
+    }
+}

Assets/Editor Toolbox/Editor/Internal/CopySerializeReferenceUtility.cs.meta

@@ -141,7 +141,6 @@ private void DoDraggingAndSelection()
 
                         //don't allow arrowing through the ends of the list
                         Index = Mathf.Clamp(Index, 0, List.arraySize - 1);
-
                     }
 
                     break;
@@ -474,7 +473,8 @@ public void AppendElement()
             var property = List.GetArrayElementAtIndex(Index);
             var newValue = overrideNewElementCallback(Index);
             //update property directly by the reflection
-            property.SetProperValue(property.GetFieldInfo(), newValue, false);
+            var fieldInfo = property.GetFieldInfo();
+            property.SetProperValue(fieldInfo, newValue, false);
         }
 
         public void RemoveElement()