added some stuff

Assets/Editor/OptionalPropertyDrawer.cs

@@ -0,0 +1,39 @@
+using UnityEditor;
+using UnityEngine;
+using Lemon.GenericLib.Generics;
+
+namespace Lemon.GenericLib.Editor {
+    [CustomPropertyDrawer(typeof(Optional<>))]
+    public class OptionalPropertyDrawer : PropertyDrawer
+    {
+        public override float GetPropertyHeight(SerializedProperty property, GUIContent label)
+        {
+            var valueProperty = property.FindPropertyRelative("value");
+            return EditorGUI.GetPropertyHeight(valueProperty);
+        }
+
+        public override void OnGUI(
+            Rect position,
+            SerializedProperty property,
+            GUIContent label
+        )
+        {
+            var valueProperty = property.FindPropertyRelative("value");
+            var enabledProperty = property.FindPropertyRelative("enabled");
+
+            EditorGUI.BeginProperty(position, label, property);
+            position.width -= 24;
+            EditorGUI.BeginDisabledGroup(!enabledProperty.boolValue);
+            EditorGUI.PropertyField(position, valueProperty, label, true);
+            EditorGUI.EndDisabledGroup();
+
+            position.x += position.width + 24;
+            position.width = position.height = EditorGUI.GetPropertyHeight(enabledProperty);
+            position.x -= position.width;
+            EditorGUI.PropertyField(position, enabledProperty, GUIContent.none);
+            EditorGUI.EndProperty();
+        }
+    }
+}
+
+

Assets/Editor/OptionalPropertyDrawer.cs.meta

@@ -0,0 +1,11 @@
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+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
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