Fix dropdown overlap in Unity 2023.2

Assets/MackySoft/MackySoft.SerializeReferenceExtensions/Editor/ManagedReferenceUtility.cs

@@ -4,15 +4,17 @@
 using UnityEditor;
 using UnityEngine;
 
-namespace MackySoft.SerializeReferenceExtensions.Editor {
+namespace MackySoft.SerializeReferenceExtensions.Editor
+{
+
 	public static class ManagedReferenceUtility {
 
 		public static object SetManagedReference (this SerializedProperty property,Type type) {
 			object result = null;
 
 #if UNITY_2021_3_OR_NEWER
 			// NOTE: managedReferenceValue getter is available only in Unity 2021.3 or later.
-			if (property.managedReferenceValue != null && type != null)
+			if ((type != null) && (property.managedReferenceValue != null))
 			{
 				// Restore an previous values from json.
 				string json = JsonUtility.ToJson(property.managedReferenceValue);

Assets/MackySoft/MackySoft.SerializeReferenceExtensions/Editor/SerializedPropertyExtensions.cs

@@ -0,0 +1,31 @@
+#if UNITY_2019_3_OR_NEWER
+using System.Collections.Generic;
+using UnityEditor;
+
+namespace MackySoft.SerializeReferenceExtensions.Editor
+{
+	public static class SerializedPropertyExtensions
+	{
+		public static IEnumerable<SerializedProperty> GetChildProperties (this SerializedProperty parent, int depth = 1)
+		{
+			parent = parent.Copy();
+
+			int depthOfParent = parent.depth;
+			var enumerator = parent.GetEnumerator();
+
+			while (enumerator.MoveNext())
+			{
+				if (enumerator.Current is not SerializedProperty childProperty)
+				{
+					continue;
+				}
+				if (childProperty.depth > (depthOfParent + depth))
+				{
+					continue;
+				}
+				yield return childProperty.Copy();
+			}
+		}
+	}
+}
+#endif

Assets/MackySoft/MackySoft.SerializeReferenceExtensions/Editor/SubclassSelectorDrawer.cs

@@ -31,51 +31,74 @@ struct TypePopupCache {
 
 		SerializedProperty m_TargetProperty;
 
-		public override void OnGUI (Rect position,SerializedProperty property,GUIContent label) {
-			EditorGUI.BeginProperty(position,label,property);
-
-			if (property.propertyType == SerializedPropertyType.ManagedReference) {
+		public override void OnGUI (Rect position, SerializedProperty property, GUIContent label)
+		{
+			EditorGUI.BeginProperty(position, label, property);
 
-				// render label first to avoid label overlap for lists
+			if (property.propertyType == SerializedPropertyType.ManagedReference)
+			{
+				// Render label first to avoid label overlap for lists
 				Rect foldoutLabelRect = new Rect(position);
 				foldoutLabelRect.height = EditorGUIUtility.singleLineHeight;
-				foldoutLabelRect.x += EditorGUI.indentLevel * 12;
+				foldoutLabelRect = EditorGUI.IndentedRect(foldoutLabelRect);
 				Rect popupPosition = EditorGUI.PrefixLabel(foldoutLabelRect, label);
 
 				// Draw the subclass selector popup.
-				if (EditorGUI.DropdownButton(popupPosition,GetTypeName(property),FocusType.Keyboard)) {
+				if (EditorGUI.DropdownButton(popupPosition, GetTypeName(property), FocusType.Keyboard))
+				{
 					TypePopupCache popup = GetTypePopup(property);
 					m_TargetProperty = property;
 					popup.TypePopup.Show(popupPosition);
 				}
 
-				// Check if a custom property drawer exists for this type.
-				PropertyDrawer customDrawer = GetCustomPropertyDrawer(property);
-				if (customDrawer != null)
+				// Draw the foldout.
+				if (!string.IsNullOrEmpty(property.managedReferenceFullTypename))
 				{
-					// Draw the property with custom property drawer.
 					Rect foldoutRect = new Rect(position);
 					foldoutRect.height = EditorGUIUtility.singleLineHeight;
+					foldoutRect.x -= 12;
 					property.isExpanded = EditorGUI.Foldout(foldoutRect, property.isExpanded, GUIContent.none, true);
+				}
 
-					if (property.isExpanded)
+				// Draw property if expanded.
+				if (property.isExpanded)
+				{
+					using (new EditorGUI.IndentLevelScope())
 					{
-						using (new EditorGUI.IndentLevelScope())
+						// Check if a custom property drawer exists for this type.
+						PropertyDrawer customDrawer = GetCustomPropertyDrawer(property);
+						if (customDrawer != null)
 						{
+							// Draw the property with custom property drawer.
 							Rect indentedRect = position;
 							float foldoutDifference = EditorGUIUtility.singleLineHeight + EditorGUIUtility.standardVerticalSpacing;
 							indentedRect.height = customDrawer.GetPropertyHeight(property, label);
 							indentedRect.y += foldoutDifference;
 							customDrawer.OnGUI(indentedRect, property, label);
 						}
+						else
+						{
+							// Draw the properties of the child elements.
+							// NOTE: In the following code, since the foldout layout isn't working properly, I'll iterate through the properties of the child elements myself.
+							// EditorGUI.PropertyField(position, property, GUIContent.none, true);
+
+							Rect childPosition = position;
+							childPosition.y += EditorGUIUtility.singleLineHeight + EditorGUIUtility.standardVerticalSpacing;
+							foreach (SerializedProperty childProperty in property.GetChildProperties())
+							{
+								float height = EditorGUI.GetPropertyHeight(childProperty, new GUIContent(childProperty.displayName, childProperty.tooltip), true);
+								childPosition.height = height;
+								EditorGUI.PropertyField(childPosition, childProperty, true);
+
+								childPosition.y += height + EditorGUIUtility.standardVerticalSpacing;
+							}
+						}
 					}
 				}
-				else
-				{
-					EditorGUI.PropertyField(position, property, GUIContent.none, true);
-				}
-			} else {
-				EditorGUI.LabelField(position,label,k_IsNotManagedReferenceLabel);
+			}
+			else
+			{
+				EditorGUI.LabelField(position, label, k_IsNotManagedReferenceLabel);
 			}
 
 			EditorGUI.EndProperty();
@@ -117,7 +140,6 @@ PropertyDrawer GetCustomPropertyDrawer (SerializedProperty property)
 					foreach (var targetObject in m_TargetProperty.serializedObject.targetObjects) {
 						SerializedObject individualObject = new SerializedObject(targetObject);
 						SerializedProperty individualProperty = individualObject.FindProperty(m_TargetProperty.propertyPath);
-
 						object obj = individualProperty.SetManagedReference(type);
 						individualProperty.isExpanded = (obj != null);