public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
{
EditorGUI.BeginProperty(position, label, property);
if (property.propertyType == SerializedPropertyType.ManagedReference)
{
TypePopupCache popup = GetTypePopup(property);
// Draw the subclass selector popup.
Rect popupPosition = new Rect(position);
popupPosition.width -= EditorGUIUtility.labelWidth;
popupPosition.x += EditorGUIUtility.labelWidth;
popupPosition.height = EditorGUIUtility.singleLineHeight;
if (EditorGUI.DropdownButton(popupPosition, new GUIContent(GetTypeName(property)), FocusType.Keyboard))
{
m_TargetProperty = property;
popup.TypePopup.Show(popupPosition);
}
// Draw the managed reference property.
EditorGUI.PropertyField(position, property, label, true);
}
else
{
EditorGUI.LabelField(position, label, k_IsNotManagedReferenceLabel);
}
EditorGUI.EndProperty();
}
TypePopupCache GetTypePopup(SerializedProperty property)
{
// Cache this string. This property internally call Assembly.GetName, which result in a large allocation.
string managedReferenceFieldTypename = property.managedReferenceFieldTypename;
if (!m_TypePopups.TryGetValue(managedReferenceFieldTypename, out TypePopupCache result))
{
var state = new AdvancedDropdownState();
Type baseType = ManagedReferenceUtility.GetType(managedReferenceFieldTypename);
var popup = new AdvancedTypePopup(
TypeCache.GetTypesDerivedFrom(baseType).Append(baseType).Where(p =>
(p.IsPublic || p.IsNestedPublic) &&
!p.IsAbstract &&
!p.IsGenericType &&
!k_UnityObjectType.IsAssignableFrom(p) &&
Attribute.IsDefined(p, typeof(SerializableAttribute))
),
k_MaxTypePopupLineCount,
state
);
popup.OnItemSelected += item => {
Type type = item.Type;
object obj = m_TargetProperty.SetManagedReference(type);
m_TargetProperty.isExpanded = (obj != null);
m_TargetProperty.serializedObject.ApplyModifiedProperties();
m_TargetProperty.serializedObject.Update();
};
result = new TypePopupCache(popup, state);
m_TypePopups.Add(managedReferenceFieldTypename, result);
}
return(result);
}
