Refactor type search logic into TypeCandiateService

Replaces TypeSearch with TypeCandiateService and TypeSearchService for improved modularity and extensibility. Updates SubclassSelectorDrawer to use the new service. Removes obsolete TypeSearch and related files.

Author: mackysoft

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

@@ -150,8 +150,9 @@ TypePopupCache GetTypePopup (SerializedProperty property) {
 				var state = new AdvancedDropdownState();
 
 				Type baseType = ManagedReferenceUtility.GetType(managedReferenceFieldTypename);
-				var popup = new AdvancedTypePopup(
-					TypeSearch.GetTypes(baseType),
+				var types = TypeSearchService.TypeCandiateService.GetDisplayableTypes(baseType);
+                var popup = new AdvancedTypePopup(
+                    types,
 					k_MaxTypePopupLineCount,
 					state
 				);

Assets/MackySoft/MackySoft.SerializeReferenceExtensions/Editor/TypeCandiateService.cs

@@ -0,0 +1,45 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace MackySoft.SerializeReferenceExtensions.Editor
+{
+    public sealed class TypeCandiateService
+    {
+
+        private readonly ITypeCandiateProvider typeCandiateProvider;
+        private readonly IIntrinsicTypePolicy intrinsicTypePolicy;
+        private readonly ITypeCompatibilityPolicy typeCompatibilityPolicy;
+
+        private readonly Dictionary<Type, Type[]> typeCache = new Dictionary<Type, Type[]>();
+
+        public TypeCandiateService (ITypeCandiateProvider typeCandiateProvider, IIntrinsicTypePolicy intrinsicTypePolicy, ITypeCompatibilityPolicy typeCompatibilityPolicy)
+        {
+            this.typeCandiateProvider = typeCandiateProvider ?? throw new ArgumentNullException(nameof(typeCandiateProvider));
+            this.intrinsicTypePolicy = intrinsicTypePolicy ?? throw new ArgumentNullException(nameof(intrinsicTypePolicy));
+            this.typeCompatibilityPolicy = typeCompatibilityPolicy ?? throw new ArgumentNullException(nameof(typeCompatibilityPolicy));
+        }
+
+        public IReadOnlyList<Type> GetDisplayableTypes (Type baseType)
+        {
+            if (baseType == null)
+            {
+                throw new ArgumentNullException(nameof(baseType));
+            }
+            if (typeCache.TryGetValue(baseType, out Type[] cachedTypes))
+            {
+                return cachedTypes;
+            }
+
+            var candiateTypes = typeCandiateProvider.GetTypeCandidates(baseType);
+            var result = candiateTypes
+                .Where(intrinsicTypePolicy.IsAllowed)
+                .Where(t => typeCompatibilityPolicy.IsCompatible(baseType, t))
+                .Distinct()
+                .ToArray();
+
+            typeCache.Add(baseType, result);
+            return result;
+        }
+    }
+}

Assets/MackySoft/MackySoft.SerializeReferenceExtensions/Editor/TypeCandiateService.cs.meta

@@ -0,0 +1,26 @@
+namespace MackySoft.SerializeReferenceExtensions.Editor
+{
+    public static class TypeSearchService
+    {
+
+        public static readonly IIntrinsicTypePolicy IntrinsicTypePolicy;
+        public static readonly ITypeCompatibilityPolicy TypeCompatibilityPolicy;
+        public static readonly ITypeCandiateProvider TypeCandiateProvider;
+        public static readonly TypeCandiateService TypeCandiateService;
+
+        static TypeSearchService ()
+        {
+            IntrinsicTypePolicy = DefaultIntrinsicTypePolicy.Instance;
+
+#if UNITY_2023_2_OR_NEWER
+            TypeCompatibilityPolicy = Unity_2023_2_OrNewer_GenericVarianceTypeCompatibilityPolicy.Instance;
+            TypeCandiateProvider = Unity_2023_2_OrNewer_TypeCandiateProvider.Instance;
+#else
+            TypeCompatibilityPolicy = DefaultTypeCompatibilityPolicy.Instance;
+            TypeCandiateProvider = DefaultTypeCandiateProvider.Instance;
+#endif
+
+            TypeCandiateService = new TypeCandiateService(TypeCandiateProvider, IntrinsicTypePolicy, TypeCompatibilityPolicy);
+        }
+    }
+}