EnableIfDrawer.cs

#if UNITY_EDITOR
using UnityEditor;
using UnityEngine;
 
#pragma warning disable IDE0130
namespace SCG.Editor
#pragma warning restore IDE0130
{
    [CustomPropertyDrawer(typeof(EnableIfAttribute))]
    internal sealed class EnableIfDrawer : PropertyDrawer
    {
        public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
        {
            if (property == null)
                return;
 
            var isEnabled = attribute is not EnableIfAttribute enableIf ||
                            ConditionalMemberEvaluator.ShouldEnable(property, enableIf);
 
            EditorGUI.BeginProperty(position, label, property);
            using (new EditorGUI.DisabledScope(!isEnabled))
            {
                if (ConditionalMemberEvaluator.TryGetBuiltInDrawer(property, fieldInfo, out var builtInDrawer))
                {
                    ConditionalMemberEvaluator.DrawBuiltInDrawer(builtInDrawer, position, property, label);
                }
                else
                {
                    EditorGUI.PropertyField(position, property, label, true);
                }
            }
 
            EditorGUI.EndProperty();
        }
 
        public override float GetPropertyHeight(SerializedProperty property, GUIContent label) =>
            ConditionalMemberEvaluator.TryGetBuiltInDrawer(property, fieldInfo, out var builtInDrawer)
                ? ConditionalMemberEvaluator.GetBuiltInDrawerHeight(builtInDrawer, property, label)
                : EditorGUI.GetPropertyHeight(property, label, true);
    }
}
#endif