fix: set label text before BeginProperty call

Author: jhodk

Assets/Example/Example.cs

@@ -9,6 +9,8 @@ public abstract class Food
     public string name;
 
     public float kcal;
+
+    public override string ToString () => $"{name} ({kcal} kcal)";
 }
 
 [Serializable]
@@ -89,6 +91,15 @@ public class Example : MonoBehaviour
         new Peach(),
         new Grape()
     };
+    
+    // UseToStringAsLabel support on UNITY_2021_3_OR_NEWER
+    [SerializeReference, SubclassSelector(UseToStringAsLabel = true)]
+    public List<Food> foodsThree = new List<Food>
+    {
+        new Apple(),
+        new Peach(),
+        new Grape()
+    };
 }
 
 #if UNITY_EDITOR

Assets/Example/Example.unity

@@ -260,9 +260,28 @@ MonoBehaviour:
   - rid: 9020349853700980772
   - rid: 9020349853700980773
   - rid: 9020349853700980774
+  foodsThree:
+  - rid: 7418200600248058228
+  - rid: 7418200600248058229
+  - rid: 7418200600248058230
   references:
     version: 2
     RefIds:
+    - rid: 7418200600248058228
+      type: {class: Apple, ns: , asm: Assembly-CSharp}
+      data:
+        name: Apple
+        kcal: 100
+    - rid: 7418200600248058229
+      type: {class: Peach, ns: , asm: Assembly-CSharp}
+      data:
+        name: Peach
+        kcal: 100
+    - rid: 7418200600248058230
+      type: {class: Grape, ns: , asm: Assembly-CSharp}
+      data:
+        name: Grape
+        kcal: 100
     - rid: 9020349853700980763
       type: {class: Apple, ns: , asm: Assembly-CSharp}
       data:

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

@@ -35,20 +35,12 @@ public TypePopupCache (AdvancedTypePopup typePopup, AdvancedDropdownState state)
 
         public override void OnGUI (Rect position, SerializedProperty property, GUIContent label)
         {
-            EditorGUI.BeginProperty(position, label, property);
 
             if (property.propertyType == SerializedPropertyType.ManagedReference)
             {
-                // Render label first to avoid label overlap for lists
-                Rect foldoutLabelRect = new Rect(position);
-                foldoutLabelRect.height = EditorGUIUtility.singleLineHeight;
-
-                // NOTE: IndentedRect should be disabled as it causes extra indentation.
-                //foldoutLabelRect = EditorGUI.IndentedRect(foldoutLabelRect);
-                Rect popupPosition = EditorGUI.PrefixLabel(foldoutLabelRect, label);
-
 #if UNITY_2021_3_OR_NEWER
                 // Override the label text with the ToString() of the managed reference.
+                // Must be called before EditorGUI.BeginProperty
                 var subclassSelectorAttribute = (SubclassSelectorAttribute)attribute;
                 if (subclassSelectorAttribute.UseToStringAsLabel && !property.hasMultipleDifferentValues)
                 {
@@ -59,6 +51,15 @@ public override void OnGUI (Rect position, SerializedProperty property, GUIConte
                     }
                 }
 #endif
+                
+                EditorGUI.BeginProperty(position, label, property);
+                // Render label first to avoid label overlap for lists
+                Rect foldoutLabelRect = new Rect(position);
+                foldoutLabelRect.height = EditorGUIUtility.singleLineHeight;
+
+                // NOTE: IndentedRect should be disabled as it causes extra indentation.
+                //foldoutLabelRect = EditorGUI.IndentedRect(foldoutLabelRect);
+                Rect popupPosition = EditorGUI.PrefixLabel(foldoutLabelRect, label);
 
                 // Draw the subclass selector popup.
                 if (EditorGUI.DropdownButton(popupPosition, GetTypeName(property), FocusType.Keyboard))
@@ -129,6 +130,7 @@ public override void OnGUI (Rect position, SerializedProperty property, GUIConte
             }
             else
             {
+                EditorGUI.BeginProperty(position, label, property);
                 EditorGUI.LabelField(position, label, IsNotManagedReferenceLabel);
             }