Unity UITK Auto Drawer

AutoDrawer.cs

    public static class FieldFactory
    {
        private delegate VisualElement CreationDelegate(Type t, object o);
        
        private static readonly Dictionary<Type, CreationDelegate> creationDictionary =
            new Dictionary<Type, CreationDelegate>();
        private static readonly List<Type> creationTypes = new List<Type>();
        
        private static bool initialized = false;

        private static void Register<T>(CreationDelegate creationAction)
        {
            creationTypes.Add(typeof(T));
            creationDictionary.Add(typeof(T), creationAction);
        }

        private static void FastRegister<ArgType, FieldType>()
        where FieldType: BaseField<ArgType>, new()
        {
            Register<ArgType>(ConstructField<ArgType, FieldType>);
        }

        private static FieldType ConstructField<ArgType, FieldType>(Type t, object o)
        where FieldType: BaseField<ArgType>, new()
        {
            var m = new FieldType();
            if(o != null)
                m.SetValueWithoutNotify((ArgType)o);
            return m;
        }

        private static void RegisterAll()
        {
            FastRegister<float, FloatField>();
            FastRegister<int, IntegerField>();
            FastRegister<string, TextField>();
            FastRegister<Vector2, Vector2Field>();
            FastRegister<Vector3, Vector3Field>();
            FastRegister<Vector4, Vector4Field>();
            FastRegister<Vector2Int, Vector2IntField>();
            FastRegister<Vector3Int, Vector3IntField>();
            FastRegister<Bounds, BoundsField>();
            FastRegister<BoundsInt, BoundsIntField>();
            FastRegister<Color, ColorField>();
            FastRegister<AnimationCurve, CurveField>();
            FastRegister<Gradient, GradientField>();
            FastRegister<Rect, RectField>();
            FastRegister<RectInt, RectIntField>();
            FastRegister<bool, Toggle>();
            Register<UnityEngine.Object>((t, o) =>
            {
                var m = new ObjectField {objectType = t, allowSceneObjects = true};
                if (o != null)
                {
                    m.SetValueWithoutNotify((UnityEngine.Object) o);
                }
                return m;
            });
            Register<Enum>(CreateEnum);
        }
        
        private static VisualElement CreateEnum(Type t, object o)
        {
            if (o == null)
                return null;
            
            var en = (Enum)o;
            bool isFlags = t.GetCustomAttributes<FlagsAttribute>().Any();

            static EnumFlagsField CreateFlagsEnums(Enum someEnum)
            {
                EnumFlagsField ff = new EnumFlagsField(someEnum);
                return ff;
            }

            static PopupField<string> CreateNormalEnumField(Enum someEnum, Type t)
            {
                Array vals = Enum.GetValues(t);
                List<string> strings = new List<string>();
                foreach (var item in vals)
                {
                    strings.Add(item.ToString());
                }

                if (strings.Count == 0)
                    return null;

                PopupField<string> pf = new PopupField<string>(strings, someEnum.ToString());
                pf.SetValueWithoutNotify(someEnum.ToString());
                return pf;
            }

            return isFlags ? CreateFlagsEnums(en) as VisualElement : CreateNormalEnumField(en, t);
        }

        private static CreationDelegate CheckIfRegistered(Type t)
        {
            if (!initialized)
            {
                RegisterAll();
                initialized = true;
            }

            //Check for exact matches
            if (creationDictionary.TryGetValue(t, out var creationFunc)) 
                return creationFunc;
            
            //We found no exact match, our fall back is checking the entire inheritance tree.
            return (from item 
                in creationTypes 
                where item.IsAssignableFrom(t)
                select creationDictionary[item]).FirstOrDefault();
        }
        
        public static VisualElement Create(Type t, object someObject)
        {
            CreationDelegate func = CheckIfRegistered(t);
            return func?.Invoke(t, someObject);
        }

        public static VisualElement Create<T>(object someObject = null)
        {
            CreationDelegate func = CheckIfRegistered(typeof(T));
            return func?.Invoke(typeof(T), someObject);
        }

        public static VisualElement Create<T>(T someObject)
        {
            CreationDelegate func = CheckIfRegistered(typeof(T));
            return func?.Invoke(typeof(T), someObject);
        }
     }