Make Attribute Drawers Generic

Alchemy/Assets/Alchemy/Editor/AlchemyAttributeDrawer.cs

@@ -1,22 +1,29 @@
 using System;
+using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
 using UnityEditor;
 using UnityEngine.UIElements;
 
 namespace Alchemy.Editor
 {
+    public interface IAlchemyAttributeDrawer
+    {
+        void SetContext(SerializedObject serializedObject, SerializedProperty serializedProperty, object target, MemberInfo memberInfo, Attribute attribute, VisualElement targetElement);
+        void OnCreateElement();
+    }
+
     /// <summary>
     /// Base class for extending drawing processing for fields with Alchemy attributes.
     /// </summary>
-    public abstract class AlchemyAttributeDrawer
+    public abstract class AlchemyAttributeDrawer<T> : IAlchemyAttributeDrawer where T : Attribute
     {
-        SerializedObject serializedObject;
-        SerializedProperty serializedProperty;
-        object target;
-        MemberInfo memberInfo;
-        Attribute attribute;
-        VisualElement targetElement;
+        private SerializedObject serializedObject;
+        private SerializedProperty serializedProperty;
+        private object target;
+        private MemberInfo memberInfo;
+        private T attribute;
+        private VisualElement targetElement;
 
         /// <summary>
         /// Target serialized object.
@@ -41,7 +48,7 @@ public abstract class AlchemyAttributeDrawer
         /// <summary>
         /// Target attribute.
         /// </summary>
-        public Attribute Attribute => attribute;
+        public T Attribute => attribute;
 
         /// <summary>
         /// Target visual element.
@@ -53,25 +60,14 @@ public abstract class AlchemyAttributeDrawer
         /// </summary>
         public abstract void OnCreateElement();
 
-        internal static void ExecutePropertyDrawers(SerializedObject serializedObject, SerializedProperty property, object target, MemberInfo memberInfo, VisualElement memberElement)
+        void IAlchemyAttributeDrawer.SetContext(SerializedObject serializedObject, SerializedProperty serializedProperty, object target, MemberInfo memberInfo, Attribute attribute, VisualElement targetElement)
         {
-            var attributes = memberInfo.GetCustomAttributes();
-            var processorTypes = TypeCache.GetTypesWithAttribute(typeof(CustomAttributeDrawerAttribute));
-            foreach (var attribute in attributes)
-            {
-                var processorType = processorTypes.FirstOrDefault(x => x.IsSubclassOf(typeof(AlchemyAttributeDrawer)) && x.GetCustomAttribute<CustomAttributeDrawerAttribute>().targetAttributeType == attribute.GetType());
-                if (processorType == null) continue;
-
-                var processor = (AlchemyAttributeDrawer)Activator.CreateInstance(processorType);
-                processor.serializedObject = serializedObject;
-                processor.serializedProperty = property;
-                processor.target = target;
-                processor.memberInfo = memberInfo;
-                processor.attribute = attribute;
-                processor.targetElement = memberElement;
-
-                processor.OnCreateElement();
-            }
+            this.serializedObject = serializedObject;
+            this.serializedProperty = serializedProperty;
+            this.target = target;
+            this.memberInfo = memberInfo;
+            this.attribute = attribute as T;
+            this.targetElement = targetElement;
         }
     }
 }

Alchemy/Assets/Alchemy/Editor/AlchemyAttributeDrawerHelper.cs

@@ -0,0 +1,27 @@
+using System;
+using System.Linq;
+using System.Reflection;
+using UnityEditor;
+using UnityEngine.UIElements;
+
+namespace Alchemy.Editor
+{
+    internal static class AlchemyAttributeDrawerHelper
+    {
+        internal static void ExecutePropertyDrawers(SerializedObject serializedObject, SerializedProperty property, object target, MemberInfo memberInfo, VisualElement memberElement)
+        {
+            var attributes = memberInfo.GetCustomAttributes();
+            var processorTypes = TypeCache.GetTypesWithAttribute(typeof(CustomAttributeDrawerAttribute)).Where(x => x.IsSubclassOfGeneric(typeof(AlchemyAttributeDrawer<>)));
+            foreach (var attribute in attributes)
+            {
+                var processorType = processorTypes.FirstOrDefault(x => x.GetCustomAttribute<CustomAttributeDrawerAttribute>().targetAttributeType == attribute.GetType());
+                if (processorType == null) continue;
+
+                var processor = (IAlchemyAttributeDrawer)Activator.CreateInstance(processorType);
+                processor.SetContext(serializedObject, property, target, memberInfo, attribute, memberElement);
+
+                processor.OnCreateElement();
+            }
+        }
+    }
+}

Alchemy/Assets/Alchemy/Editor/BuiltinAttributeDrawers.cs

@@ -9,7 +9,7 @@
 namespace Alchemy.Editor.Drawers
 {
     [CustomAttributeDrawer(typeof(ReadOnlyAttribute))]
-    public sealed class ReadOnlyDrawer : AlchemyAttributeDrawer
+    public sealed class ReadOnlyDrawer : AlchemyAttributeDrawer<ReadOnlyAttribute>
     {
         public override void OnCreateElement()
         {
@@ -18,7 +18,7 @@ public override void OnCreateElement()
     }
 
     [CustomAttributeDrawer(typeof(IndentAttribute))]
-    public sealed class IndentDrawer : AlchemyAttributeDrawer
+    public sealed class IndentDrawer : AlchemyAttributeDrawer<IndentAttribute>
     {
         const float IndentPadding = 15f;
 
@@ -36,7 +36,7 @@ void AddPadding()
     }
 
     [CustomAttributeDrawer(typeof(HideInPlayModeAttribute))]
-    public sealed class HideInPlayModeDrawer : AlchemyAttributeDrawer
+    public sealed class HideInPlayModeDrawer : AlchemyAttributeDrawer<HideInPlayModeAttribute>
     {
         public override void OnCreateElement()
         {
@@ -45,7 +45,7 @@ public override void OnCreateElement()
     }
 
     [CustomAttributeDrawer(typeof(HideInEditModeAttribute))]
-    public sealed class HideInEditModeDrawer : AlchemyAttributeDrawer
+    public sealed class HideInEditModeDrawer : AlchemyAttributeDrawer<HideInEditModeAttribute>
     {
         public override void OnCreateElement()
         {
@@ -54,7 +54,7 @@ public override void OnCreateElement()
     }
 
     [CustomAttributeDrawer(typeof(DisableInPlayModeAttribute))]
-    public sealed class DisableInPlayModeDrawer : AlchemyAttributeDrawer
+    public sealed class DisableInPlayModeDrawer : AlchemyAttributeDrawer<DisableInEditModeAttribute>
     {
         public override void OnCreateElement()
         {
@@ -63,7 +63,7 @@ public override void OnCreateElement()
     }
 
     [CustomAttributeDrawer(typeof(DisableInEditModeAttribute))]
-    public sealed class DisableInEditModeDrawer : AlchemyAttributeDrawer
+    public sealed class DisableInEditModeDrawer : AlchemyAttributeDrawer<DisableInEditModeAttribute>
     {
         public override void OnCreateElement()
         {
@@ -72,7 +72,7 @@ public override void OnCreateElement()
     }
 
     [CustomAttributeDrawer(typeof(HideLabelAttribute))]
-    public sealed class HideLabelDrawer : AlchemyAttributeDrawer
+    public sealed class HideLabelDrawer : AlchemyAttributeDrawer<HideLabelAttribute>
     {
         public override void OnCreateElement()
         {
@@ -89,11 +89,11 @@ public override void OnCreateElement()
     }
 
     [CustomAttributeDrawer(typeof(LabelTextAttribute))]
-    public sealed class LabelTextDrawer : AlchemyAttributeDrawer
+    public sealed class LabelTextDrawer : AlchemyAttributeDrawer<LabelTextAttribute>
     {
         public override void OnCreateElement()
         {
-            var labelTextAttribute = (LabelTextAttribute)Attribute;
+            var labelTextAttribute = Attribute;
 
             switch (TargetElement)
             {
@@ -116,11 +116,11 @@ public override void OnCreateElement()
     }
 
     [CustomAttributeDrawer(typeof(LabelWidthAttribute))]
-    public sealed class LabelWidthDrawer : AlchemyAttributeDrawer
+    public sealed class LabelWidthDrawer : AlchemyAttributeDrawer<LabelWidthAttribute>
     {
         public override void OnCreateElement()
         {
-            var width = ((LabelWidthAttribute)Attribute).Width;
+            var width = Attribute.Width;
 
             if (TargetElement is AlchemyPropertyField field && field.FieldElement is PropertyField)
             {
@@ -141,55 +141,55 @@ public override void OnCreateElement()
     }
 
     [CustomAttributeDrawer(typeof(HideIfAttribute))]
-    public sealed class HideIfDrawer : TrackSerializedObjectAttributeDrawer
+    public sealed class HideIfDrawer : TrackSerializedObjectAttributeDrawer<HideIfAttribute>
     {
         protected override void OnInspectorChanged()
         {
-            var condition = ReflectionHelper.GetValueBool(Target, ((HideIfAttribute)Attribute).Condition);
+            var condition = ReflectionHelper.GetValueBool(Target, Attribute.Condition);
             TargetElement.style.display = condition ? DisplayStyle.None : DisplayStyle.Flex;
         }
     }
 
     [CustomAttributeDrawer(typeof(ShowIfAttribute))]
-    public sealed class ShowIfDrawer : TrackSerializedObjectAttributeDrawer
+    public sealed class ShowIfDrawer : TrackSerializedObjectAttributeDrawer<ShowIfAttribute>
     {
         protected override void OnInspectorChanged()
         {
-            var condition = ReflectionHelper.GetValueBool(Target, ((ShowIfAttribute)Attribute).Condition);
+            var condition = ReflectionHelper.GetValueBool(Target, Attribute.Condition);
             TargetElement.style.display = !condition ? DisplayStyle.None : DisplayStyle.Flex;
         }
     }
 
     [CustomAttributeDrawer(typeof(DisableIfAttribute))]
-    public sealed class DisableIfDrawer : TrackSerializedObjectAttributeDrawer
+    public sealed class DisableIfDrawer : TrackSerializedObjectAttributeDrawer<DisableIfAttribute>
     {
         protected override void OnInspectorChanged()
         {
-            var condition = ReflectionHelper.GetValueBool(Target, ((DisableIfAttribute)Attribute).Condition);
+            var condition = ReflectionHelper.GetValueBool(Target, Attribute.Condition);
             TargetElement.SetEnabled(!condition);
         }
     }
 
     [CustomAttributeDrawer(typeof(EnableIfAttribute))]
-    public sealed class EnableIfDrawer : TrackSerializedObjectAttributeDrawer
+    public sealed class EnableIfDrawer : TrackSerializedObjectAttributeDrawer<EnableIfAttribute>
     {
         protected override void OnInspectorChanged()
         {
-            var condition = ReflectionHelper.GetValueBool(Target, ((EnableIfAttribute)Attribute).Condition);
+            var condition = ReflectionHelper.GetValueBool(Target, Attribute.Condition);
             TargetElement.SetEnabled(condition);
         }
     }
 
     [CustomAttributeDrawer(typeof(RequiredAttribute))]
-    public sealed class RequiredDrawer : TrackSerializedObjectAttributeDrawer
+    public sealed class RequiredDrawer : TrackSerializedObjectAttributeDrawer<RequiredAttribute>
     {
         HelpBox helpBox;
 
         public override void OnCreateElement()
         {
             if (SerializedProperty.propertyType != SerializedPropertyType.ObjectReference) return;
 
-            var message = ((RequiredAttribute)Attribute).Message ?? ObjectNames.NicifyVariableName(SerializedProperty.displayName) + " is required.";
+            var message = Attribute.Message ?? ObjectNames.NicifyVariableName(SerializedProperty.displayName) + " is required.";
             helpBox = new HelpBox(message, HelpBoxMessageType.Error);
 
             var parent = TargetElement.parent;
@@ -205,13 +205,13 @@ protected override void OnInspectorChanged()
     }
 
     [CustomAttributeDrawer(typeof(ValidateInputAttribute))]
-    public sealed class ValidateInputDrawer : TrackSerializedObjectAttributeDrawer
+    public sealed class ValidateInputDrawer : TrackSerializedObjectAttributeDrawer<ValidateInputAttribute>
     {
         HelpBox helpBox;
 
         public override void OnCreateElement()
         {
-            var message = ((ValidateInputAttribute)Attribute).Message ?? ObjectNames.NicifyVariableName(SerializedProperty.displayName) + " is not valid.";
+            var message = Attribute.Message ?? ObjectNames.NicifyVariableName(SerializedProperty.displayName) + " is not valid.";
             helpBox = new HelpBox(message, HelpBoxMessageType.Error);
 
             var parent = TargetElement.parent;
@@ -222,19 +222,19 @@ public override void OnCreateElement()
 
         protected override void OnInspectorChanged()
         {
-            var result = ReflectionHelper.Invoke(Target, ((ValidateInputAttribute)Attribute).Condition, SerializedProperty.GetValue<object>());
+            var result = ReflectionHelper.Invoke(Target, Attribute.Condition, SerializedProperty.GetValue<object>());
             helpBox.style.display = result is bool flag && flag ? DisplayStyle.None : DisplayStyle.Flex;
         }
     }
 
     [CustomAttributeDrawer(typeof(HelpBoxAttribute))]
-    public sealed class HelpBoxDrawer : AlchemyAttributeDrawer
+    public sealed class HelpBoxDrawer : AlchemyAttributeDrawer<HelpBoxAttribute>
     {
         HelpBox helpBox;
 
         public override void OnCreateElement()
         {
-            var att = (HelpBoxAttribute)Attribute;
+            var att = Attribute;
             helpBox = new HelpBox(att.Message, att.MessageType);
 
             var parent = TargetElement.parent;
@@ -243,7 +243,7 @@ public override void OnCreateElement()
     }
 
     [CustomAttributeDrawer(typeof(PreviewAttribute))]
-    public sealed class PreviewDrawer : TrackSerializedObjectAttributeDrawer
+    public sealed class PreviewDrawer : TrackSerializedObjectAttributeDrawer<PreviewAttribute>
     {
         private Image image;
         private const float BorderWidth = 1f;
@@ -253,7 +253,7 @@ public override void OnCreateElement()
         {
             if (SerializedProperty == null || SerializedProperty.propertyType != SerializedPropertyType.ObjectReference) return;
 
-            var att = (PreviewAttribute)Attribute;
+            var att = Attribute;
 
             image = new Image
             {
@@ -306,11 +306,11 @@ protected override void OnInspectorChanged()
     }
 
     [CustomAttributeDrawer(typeof(HorizontalLineAttribute))]
-    public sealed class HorizontalLineDrawer : AlchemyAttributeDrawer
+    public sealed class HorizontalLineDrawer : AlchemyAttributeDrawer<HorizontalLineAttribute>
     {
         public override void OnCreateElement()
         {
-            var att = (HorizontalLineAttribute)Attribute;
+            var att = Attribute;
             var parent = TargetElement.parent;
             var lineColor = att.Color == default ? GUIHelper.LineColor : att.Color;
             var line = GUIHelper.CreateLine(lineColor, EditorGUIUtility.standardVerticalSpacing * 4f);
@@ -319,11 +319,11 @@ public override void OnCreateElement()
     }
 
     [CustomAttributeDrawer(typeof(TitleAttribute))]
-    public sealed class TitleDrawer : AlchemyAttributeDrawer
+    public sealed class TitleDrawer : AlchemyAttributeDrawer<TitleAttribute>
     {
         public override void OnCreateElement()
         {
-            var att = (TitleAttribute)Attribute;
+            var att = Attribute;
             var parent = TargetElement.parent;
 
             var title = new Label(att.TitleText)
@@ -358,7 +358,7 @@ public override void OnCreateElement()
     }
 
     [CustomAttributeDrawer(typeof(BlockquoteAttribute))]
-    public sealed class BlockquoteDrawer : AlchemyAttributeDrawer
+    public sealed class BlockquoteDrawer : AlchemyAttributeDrawer<BlockquoteAttribute>
     {
         public BlockquoteDrawer()
         {
@@ -370,7 +370,7 @@ public BlockquoteDrawer()
 
         public override void OnCreateElement()
         {
-            var att = (BlockquoteAttribute)Attribute;
+            var att = Attribute;
             var blockquote = new IMGUIContainer(() =>
             {
                 var width = EditorGUIUtility.currentViewWidth;
@@ -397,13 +397,13 @@ public override void OnCreateElement()
     }
 
     [CustomAttributeDrawer(typeof(OnValueChangedAttribute))]
-    public sealed class OnValueChangedDrawer : AlchemyAttributeDrawer
+    public sealed class OnValueChangedDrawer : AlchemyAttributeDrawer<OnValueChangedAttribute>
     {
         public override void OnCreateElement()
         {
             TargetElement.TrackPropertyValue(SerializedProperty, property =>
             {
-                var methodName = ((OnValueChangedAttribute)Attribute).MethodName;
+                var methodName = Attribute.MethodName;
 
                 var methods = ReflectionHelper.GetAllMethodsIncludingBaseNonPublic(Target.GetType())
                     .Where(x => x.Name == methodName);

Alchemy/Assets/Alchemy/Editor/Elements/ClassField.cs

@@ -51,7 +51,7 @@ public ClassField(object obj, Type type, string label)
                     var e = node.Drawer?.GetGroupElement(member.GetCustomAttribute<PropertyGroupAttribute>());
                     if (e == null) node.VisualElement.Add(element);
                     else e.Add(element);
-                    AlchemyAttributeDrawer.ExecutePropertyDrawers(null, null, obj, member, element);
+                    AlchemyAttributeDrawerHelper.ExecutePropertyDrawers(null, null, obj, member, element);
                 }
             }