升级水插件

Packages/com.waveharmonic.crest/Editor/Scripts/Utility/Shared/Attributes/Attributes.cs

@@ -147,6 +147,21 @@ namespace WaveHarmonic.Crest
     /// </summary>
     sealed class Stripped : DecoratedProperty
     {
+        public enum Style
+        {
+            None,
+            PlatformTab,
+        }
+
+        readonly bool _KeepIndent;
+        readonly Style _Style;
+
+        public Stripped(Style style = Style.None, bool indent = false)
+        {
+            _KeepIndent = indent;
+            _Style = style;
+        }
+
         internal override bool NeedsControlRectangle(SerializedProperty property) => false;
 
         internal override void OnGUI(Rect position, SerializedProperty property, GUIContent label, DecoratedDrawer drawer)
@@ -155,11 +170,33 @@ namespace WaveHarmonic.Crest
             DecoratedDrawer.s_TemporaryColor = true;
             DecoratedDrawer.s_PreviousColor = GUI.color;
 
+            if (_Style == Style.PlatformTab)
+            {
+                EditorGUI.indentLevel += 1;
+                EditorGUILayout.LabelField(label);
+                EditorGUI.indentLevel -= 1;
+            }
+
             GUI.color = new(0, 0, 0, 0);
 
-            EditorGUI.indentLevel -= 1;
+            if (!_KeepIndent) EditorGUI.indentLevel -= 1;
             EditorGUI.PropertyField(position, property, label, true);
-            EditorGUI.indentLevel += 1;
+            if (!_KeepIndent) EditorGUI.indentLevel += 1;
+
+            if (_Style == Style.PlatformTab)
+            {
+                EditorGUILayout.Space(4);
+                EditorGUILayout.EndBuildTargetSelectionGrouping();
+            }
+        }
+    }
+
+    sealed class PlatformTabs : DecoratedProperty
+    {
+        static readonly GUIContent s_DefaultTab = new(EditorGUIUtility.IconContent("d_Settings").image, "Default");
+        internal override void OnGUI(Rect position, SerializedProperty property, GUIContent label, DecoratedDrawer drawer)
+        {
+            property.intValue = Editor.Reflected.EditorGUILayout.BeginBuildTargetSelectionGrouping(s_DefaultTab);
         }
     }
 
@@ -621,29 +658,15 @@ namespace WaveHarmonic.Crest
 
     sealed class InlineToggle : DecoratedProperty
     {
-        // Add extra y offset. Needed for foldouts in foldouts so far.
-        readonly bool _Fix;
-
-        public InlineToggle(bool fix = false)
-        {
-            _Fix = fix;
-        }
-
-        internal override bool NeedsControlRectangle(SerializedProperty property)
-        {
-            return false;
-        }
-
         internal override void OnGUI(Rect position, SerializedProperty property, GUIContent label, DecoratedDrawer drawer)
         {
             var r = position;
             r.x -= 16f;
-            // Align with Space offset.
-            if (drawer.Space > 0) r.y += drawer.Space + 2f;
-            if (_Fix) r.y += EditorGUIUtility.singleLineHeight + 2f;
-            // Seems to be needed.
+
+            // Prevent click events blocking next property.
             r.width = 16f * (1f + EditorGUI.indentLevel);
-            r.height = EditorGUIUtility.singleLineHeight;
+
+            // Hide text.
             label.text = "";
 
             using (new EditorGUI.PropertyScope(r, label, property))
@@ -654,6 +677,9 @@ namespace WaveHarmonic.Crest
                 property.boolValue = EditorGUI.Toggle(r, property.boolValue);
                 EditorGUI.EndProperty();
             }
+
+            // Pull up next property. Extra space might be margin/padding.
+            GUILayout.Space(-(EditorGUIUtility.singleLineHeight + 2f));
         }
     }
 

Packages/com.waveharmonic.crest/Editor/Scripts/Utility/Shared/DecoratedDrawer.cs

@@ -11,6 +11,7 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
 using UnityEditor;
+using UnityEditorInternal;
 using UnityEngine;
 using UnityEngine.Events;
 using WaveHarmonic.Crest.Attributes;
@@ -23,19 +24,29 @@ namespace WaveHarmonic.Crest.Editor
         internal static bool s_HideInInspector = false;
         public static bool s_IsFoldout = false;
         public static bool s_IsFoldoutOpen = false;
+        public static bool s_IsList = false;
 
         public static bool s_TemporaryColor;
         public static Color s_PreviousColor;
 
+        // If instantiating ourselves. Avoids reflection.
+        public PropertyAttribute _Attribute;
+        public FieldInfo _Field;
+        PropertyAttribute Attribute => _Attribute ?? attribute;
+        FieldInfo Field => _Field ?? fieldInfo;
+
         public float Space { get; private set; }
 
+        UnityEditor.Editor _Editor;
+        Inspector _Inspector;
+
         List<object> _Decorators = null;
         List<object> Decorators
         {
             get
             {
                 // Populate list with decorators.
-                _Decorators ??= fieldInfo
+                _Decorators ??= Field
                     .GetCustomAttributes(typeof(Decorator), false)
                     .ToList();
 
@@ -44,7 +55,7 @@ namespace WaveHarmonic.Crest.Editor
         }
 
         List<Attributes.Validator> _Validators = null;
-        List<Attributes.Validator> Validators => _Validators ??= fieldInfo
+        List<Attributes.Validator> Validators => _Validators ??= Field
             .GetCustomAttributes(typeof(Attributes.Validator), false)
             .Cast<Attributes.Validator>()
             .ToList();
@@ -63,14 +74,39 @@ namespace WaveHarmonic.Crest.Editor
 
         public override float GetPropertyHeight(SerializedProperty property, GUIContent label)
         {
+            var height = base.GetPropertyHeight(property, label);
+
+            if (property.isArray)
+            {
+                // Constructor caches value and this call retrieves it.
+                var list = ReorderableList.GetReorderableListFromSerializedProperty(property);
+                list ??= new ReorderableList(property.serializedObject, property);
+                // GetHeight does not include bottom buttons height.
+                height = property.isExpanded ? list.GetHeight() + list.footerHeight : height;
+            }
+
             // Make original control rectangle be invisible because we always create our own. Zero still adds a little
             // height which becomes noticeable once multiple properties are hidden. This could be some GUI style
             // property but could not find which one.
-            return -2f;
+            return s_IsList ? height : -2f;
         }
 
         public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
         {
+            // Get the owning editor.
+            if (_Editor == null)
+            {
+                foreach (var editor in ActiveEditorTracker.sharedTracker?.activeEditors)
+                {
+                    if (editor.serializedObject == property.serializedObject)
+                    {
+                        _Editor = editor;
+                        _Inspector = editor as Inspector;
+                        break;
+                    }
+                }
+            }
+
             // Store the original GUI state so it can be reset later.
             var originalColor = GUI.color;
             var originalEnabled = GUI.enabled;
@@ -106,8 +142,8 @@ namespace WaveHarmonic.Crest.Editor
                     attribute.Decorate(position, property, label, this);
                 }
 
-                var a = (DecoratedProperty)attribute;
-                position = a.NeedsControlRectangle(property)
+                var a = (DecoratedProperty)Attribute;
+                position = a.NeedsControlRectangle(property) && (!s_IsList || property.isArray)
                     ? EditorGUILayout.GetControlRect(true, EditorGUI.GetPropertyHeight(property, label, true))
                     : position;
 
@@ -120,11 +156,15 @@ namespace WaveHarmonic.Crest.Editor
                     label = attribute.BuildLabel(label);
                 }
 
-                var skipChange = fieldInfo.FieldType == typeof(UnityEvent);
+                var skipChange = Field.FieldType == typeof(UnityEvent) || property.isArray;
+
+                var isExpanded = property.isExpanded;
+                var isUndoRedo = false;
 
                 if (!skipChange)
                 {
                     EditorGUI.BeginChangeCheck();
+                    isUndoRedo = _Inspector != null && _Inspector._UndoRedo;
                 }
 
                 var oldValue = skipChange ? null : property.boxedValue;
@@ -135,13 +175,19 @@ namespace WaveHarmonic.Crest.Editor
                     Validators[index].Validate(position, property, label, this, oldValue);
                 }
 
-                // Guard against foldouts triggering change check due to changing isExpanded.
-                if (!skipChange && EditorGUI.EndChangeCheck() && oldValue != property.boxedValue)
+                if (!skipChange && (EditorGUI.EndChangeCheck() || isUndoRedo))
                 {
                     // Apply any changes.
-                    property.serializedObject.ApplyModifiedProperties();
+                    if (!isUndoRedo)
+                    {
+                        property.serializedObject.ApplyModifiedProperties();
+                    }
 
-                    OnChange(property, oldValue);
+                    // Guard against foldouts triggering change check due to changing isExpanded.
+                    if (property.isExpanded == isExpanded)
+                    {
+                        OnChange(property, oldValue);
+                    }
                 }
 
                 for (var index = 0; index < Decorators.Count; index++)
@@ -206,6 +252,7 @@ namespace WaveHarmonic.Crest.Editor
                 var relativePath = string.Join(".", chunks[(i + 1)..]);
 
                 var nestedTarget = nestedProperty.managedReferenceValue;
+                if (nestedTarget == null) continue;
                 var nestedTargetType = nestedTarget.GetType();
 
                 foreach (var (method, attribute) in OnChangeHandlers)

Packages/com.waveharmonic.crest/Editor/Scripts/Utility/Shared/Helpers.cs

@@ -294,7 +294,13 @@ namespace WaveHarmonic.Crest.Editor
                 width = Mathf.Max(width, minimumWidth);
                 // TODO: Add option to disable this (consistent width).
                 if (!hasDropDown && minimumWidth > 0) width += k_ButtonDropDownWidth;
-                if (centerLabel && hasDropDown) style.padding.left += k_ButtonDropDownWidth;
+
+                // TODO: eyeballed based on Fix button but likely specific to it.
+                if (centerLabel && hasDropDown)
+                {
+                    style.padding.left += k_ButtonDropDownWidth / 2;
+                    width += k_ButtonDropDownWidth / 3;
+                }
 
                 if (GUILayout.Button(label, style, expandWidth ? GUILayout.ExpandWidth(true) : GUILayout.Width(width)))
                 {

Packages/com.waveharmonic.crest/Editor/Scripts/Utility/Shared/Inspector.cs

@@ -9,6 +9,7 @@ using UnityEditor;
 using UnityEngine;
 using WaveHarmonic.Crest.Editor.Internal;
 using WaveHarmonic.Crest.Internal;
+using WaveHarmonic.Crest.Internal.Compatibility;
 
 namespace WaveHarmonic.Crest.Editor
 {
@@ -25,6 +26,7 @@ namespace WaveHarmonic.Crest.Editor
 
         readonly Dictionary<FieldInfo, object> _MaterialOwners = new();
         readonly Dictionary<Material, MaterialEditor> _MaterialEditors = new();
+        readonly Dictionary<string, DecoratedDrawer> _Lists = new();
 
         public override bool RequiresConstantRepaint() => TexturePreview.s_ActiveInstance?.Open == true;
 
@@ -38,6 +40,9 @@ namespace WaveHarmonic.Crest.Editor
         {
             _MaterialOwners.Clear();
 
+            Undo.undoRedoPerformed -= OnUndoRedo;
+            Undo.undoRedoPerformed += OnUndoRedo;
+
             foreach (var field in s_AttachMaterialEditors)
             {
                 var target = (object)this.target;
@@ -74,12 +79,19 @@ namespace WaveHarmonic.Crest.Editor
 
         protected virtual void OnDisable()
         {
+            Undo.undoRedoPerformed -= OnUndoRedo;
+
             foreach (var (_, editor) in _MaterialEditors)
             {
                 Helpers.Destroy(editor);
             }
         }
 
+        protected virtual void OnChange()
+        {
+
+        }
+
         protected virtual void RenderBeforeInspectorGUI()
         {
             if (this.target is EditorBehaviour target && target._IsPrefabStageInstance)
@@ -99,6 +111,8 @@ namespace WaveHarmonic.Crest.Editor
 
             serializedObject.Update();
 
+            EditorGUI.BeginChangeCheck();
+
             using var iterator = serializedObject.GetIterator();
             if (iterator.NextVisible(true))
             {
@@ -140,6 +154,33 @@ namespace WaveHarmonic.Crest.Editor
                 using (new EditorGUI.DisabledGroupScope(property.name == "m_Script"))
 #endif
                 {
+                    // Handle lists as PropertyDrawer is not called on the list itself.
+                    if (property.isArray)
+                    {
+                        var field = property.GetFieldInfo(out var _);
+                        var attribute = field?.GetCustomAttribute<Attributes.DecoratedProperty>();
+
+                        if (field != null && attribute != null)
+                        {
+                            var id = GetPropertyIdentifier(property);
+
+                            if (!_Lists.ContainsKey(id))
+                            {
+                                _Lists[id] = new DecoratedDrawer()
+                                {
+                                    _Attribute = attribute,
+                                    _Field = field,
+                                };
+                            }
+
+                            DecoratedDrawer.s_IsList = true;
+                            var label = new GUIContent(property.displayName);
+                            _Lists[id].OnGUI(Rect.zero, property, label);
+                            DecoratedDrawer.s_IsList = false;
+                            continue;
+                        }
+                    }
+
                     // Only support top level ordering for now.
                     EditorGUILayout.PropertyField(property, includeChildren: true);
                 }
@@ -148,11 +189,18 @@ namespace WaveHarmonic.Crest.Editor
             // Need to call just in case there is no decorated property.
             serializedObject.ApplyModifiedProperties();
 
+            if (EditorGUI.EndChangeCheck())
+            {
+                OnChange();
+            }
+
             // Restore previous in case this is a nested editor.
             Current = previous;
 
             // Fixes indented validation etc.
             EditorGUI.indentLevel = 0;
+
+            _UndoRedo = false;
         }
 
         protected virtual void RenderBottomButtons()
@@ -214,6 +262,45 @@ namespace WaveHarmonic.Crest.Editor
         }
     }
 
+    // Reflection
+    partial class Inspector
+    {
+        static readonly PropertyInfo s_GUIViewCurrent = typeof(UnityEditor.Editor).Assembly.GetType("UnityEditor.GUIView").GetProperty("current", BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic);
+        static readonly PropertyInfo s_GUIViewNativeHandle = typeof(UnityEditor.Editor).Assembly.GetType("UnityEditor.GUIView").GetProperty("nativeHandle", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
+
+        // Adapted from:
+        // https://github.com/Unity-Technologies/UnityCsReference/blob/59b03b8a0f179c0b7e038178c90b6c80b340aa9f/Editor/Mono/Inspector/ReorderableListWrapper.cs#L77-L88
+        static string GetPropertyIdentifier(SerializedProperty serializedProperty)
+        {
+            // Property may be disposed.
+            try
+            {
+                var handle = -1;
+                var current = s_GUIViewCurrent.GetValue(null);
+
+                if (current != null)
+                {
+                    handle = ((IntPtr)s_GUIViewNativeHandle.GetValue(current)).ToInt32();
+                }
+
+                return serializedProperty?.propertyPath + serializedProperty.serializedObject.targetObject.GetEntityId() + handle;
+            }
+            catch (NullReferenceException)
+            {
+                return string.Empty;
+            }
+        }
+    }
+
+    partial class Inspector
+    {
+        internal bool _UndoRedo;
+        void OnUndoRedo()
+        {
+            _UndoRedo = true;
+        }
+    }
+
     // Adapted from:
     // https://gist.github.com/thebeardphantom/1ad9aee0ef8de6271fff39f1a6a3d66d
     static partial class Extensions

Packages/com.waveharmonic.crest/Editor/Scripts/Utility/Shared/Reflected.cs

@@ -0,0 +1,106 @@
+// Crest Water System
+// Copyright © 2024 Wave Harmonic. All rights reserved.
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+using UnityEditor.Build;
+using UnityEngine;
+
+namespace WaveHarmonic.Crest.Editor.Reflected
+{
+    static class BuildTargetGroup
+    {
+        public const int k_Server = -2;
+    }
+
+    static class BuildPlatform
+    {
+        internal static readonly Type s_BuildPlatformType = Type.GetType("UnityEditor.Build.BuildPlatform,UnityEditor.CoreModule");
+        internal static readonly Type s_BuildPlatformArrayType = s_BuildPlatformType.MakeArrayType();
+
+        static readonly FieldInfo s_NamedBuildTargetField = s_BuildPlatformType.GetField
+        (
+            "namedBuildTarget",
+            BindingFlags.Instance | BindingFlags.Public
+        );
+
+        public static NamedBuildTarget GetNamedBuildTarget(object platform)
+        {
+            return (NamedBuildTarget)s_NamedBuildTargetField.GetValue(platform);
+        }
+    }
+
+    static class BuildPlatforms
+    {
+        static readonly Type s_BuildPlatformsType = Type.GetType("UnityEditor.Build.BuildPlatforms,UnityEditor.CoreModule");
+        static readonly PropertyInfo s_BuildPlatformsInstanceProperty = s_BuildPlatformsType.GetProperty("instance", BindingFlags.Static | BindingFlags.Public);
+        static readonly MethodInfo s_GetValidPlatformsMethod = s_BuildPlatformsType.GetMethod("GetValidPlatforms", new Type[] { });
+        static Array s_Platforms; // Should be safe to cache.
+
+        public static Array GetValidPlatforms()
+        {
+            if (s_Platforms == null)
+            {
+                var instance = s_BuildPlatformsInstanceProperty.GetValue(null);
+
+                // We cannot just cast to the type we want it seems.
+                var enumerable = ((IEnumerable<object>)s_GetValidPlatformsMethod.Invoke(instance, null)).ToList();
+
+                s_Platforms = Array.CreateInstance(BuildPlatform.s_BuildPlatformType, enumerable.Count);
+
+                for (var i = 0; i < enumerable.Count; i++)
+                {
+                    s_Platforms.SetValue(enumerable[i], i);
+                }
+            }
+
+            return s_Platforms;
+        }
+    }
+
+    static class EditorGUILayout
+    {
+        static readonly MethodInfo s_BeginPlatformGroupingMethod = typeof(UnityEditor.EditorGUILayout).GetMethod
+        (
+            "BeginPlatformGrouping",
+            BindingFlags.Static | BindingFlags.NonPublic,
+            null,
+            new Type[]
+            {
+                BuildPlatform.s_BuildPlatformArrayType,
+                typeof(GUIContent),
+            },
+            null
+        );
+
+        static readonly object[] s_Parameters = new object[2];
+
+        public static int BeginBuildTargetSelectionGrouping(GUIContent defaultTab)
+        {
+            var platforms = BuildPlatforms.GetValidPlatforms();
+
+            s_Parameters[0] = platforms;
+            s_Parameters[1] = defaultTab;
+
+            var index = (int)s_BeginPlatformGroupingMethod.Invoke(null, s_Parameters);
+
+            if (index < 0)
+            {
+                // Default
+                return (int)UnityEditor.BuildTargetGroup.Unknown;
+            }
+
+            var target = BuildPlatform.GetNamedBuildTarget(platforms.GetValue(index));
+
+            if (target == NamedBuildTarget.Server)
+            {
+                // Server
+                return BuildTargetGroup.k_Server;
+            }
+
+            return (int)target.ToBuildTargetGroup();
+        }
+    }
+}

Packages/com.waveharmonic.crest/Editor/Scripts/Utility/Shared/Reflected.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: cd362a01f52cc4002857e9f549c641be
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Packages/com.waveharmonic.crest/Editor/Scripts/Utility/Shared/ScriptingSymbols.cs

@@ -10,7 +10,7 @@ namespace WaveHarmonic.Crest.Editor.Settings
 {
     static class ScriptingSymbols
     {
-        static NamedBuildTarget CurrentNamedBuildTarget
+        internal static NamedBuildTarget CurrentNamedBuildTarget
         {
             get
             {

Packages/com.waveharmonic.crest/Editor/Scripts/Utility/Shared/TexturePreview.cs

@@ -10,6 +10,10 @@ namespace WaveHarmonic.Crest.Editor
 {
     abstract class TexturePreview : ObjectPreview
     {
+        static readonly System.Reflection.MethodInfo s_DrawPreview = typeof(ObjectPreview).GetMethod("DrawPreview", System.Reflection.BindingFlags.Static | System.Reflection.BindingFlags.NonPublic);
+        static readonly object[] s_DrawPreviewArguments = new object[3];
+        static readonly Object[] s_DrawPreviewTargets = new Object[1];
+
         public static TexturePreview s_ActiveInstance;
         public bool Open { get; private set; }
 
@@ -101,6 +105,9 @@ namespace WaveHarmonic.Crest.Editor
                 Helpers.SafeCreateRenderTexture(ref _RenderTexture, descriptor);
                 _RenderTexture.Create();
                 Object.DestroyImmediate(_Editor);
+                // Raises both, but no way to avoid it:
+                // | The targets array should not be used inside OnSceneGUI or OnPreviewGUI. Use the single target property instead.
+                // | The serializedObject should not be used inside OnSceneGUI or OnPreviewGUI. Use the target property directly instead.
                 _Editor = UnityEditor.Editor.CreateEditor(_RenderTexture);
                 // Reset for incompatible copy.
                 descriptor = _OriginalDescriptor;
@@ -121,7 +128,13 @@ namespace WaveHarmonic.Crest.Editor
                 Graphics.CopyTexture(Texture, _RenderTexture);
             }
 
-            _Editor.DrawPreview(rect);
+            s_DrawPreviewTargets[0] = _Editor.target;
+            s_DrawPreviewArguments[0] = _Editor;
+            s_DrawPreviewArguments[1] = rect;
+            s_DrawPreviewArguments[2] = s_DrawPreviewTargets;
+
+            // Use to be _Editor.DrawPreview(rect) but spammed errors with multiple selected.
+            s_DrawPreview?.Invoke(null, s_DrawPreviewArguments);
         }
 
 #if CREST_DEBUG

Packages/com.waveharmonic.crest/Editor/Scripts/Utility/Shared/Validation.cs

@@ -9,6 +9,7 @@ using System.Collections.Generic;
 using System.Reflection;
 using UnityEditor;
 using UnityEngine;
+using WaveHarmonic.Crest.Editor;
 using WaveHarmonic.Crest.Internal;
 
 namespace WaveHarmonic.Crest.Editor
@@ -54,9 +55,9 @@ namespace WaveHarmonic.Crest.Editor
             new(),
         };
 
-        public delegate void ShowMessage(string message, string fixDescription, MessageType type, Object @object = null, FixValidation action = null, string property = null);
+        public delegate void ShowMessage(string message, string fixDescription, MessageType type, Object @object = null, FixValidation action = null, string property = null, Object caller = null);
 
-        public static void DebugLog(string message, string fixDescription, MessageType type, Object @object = null, FixValidation action = null, string property = null)
+        public static void DebugLog(string message, string fixDescription, MessageType type, Object @object = null, FixValidation action = null, string property = null, Object caller = null)
         {
             // Never log info validation to console.
             if (type == MessageType.Info)
@@ -64,22 +65,27 @@ namespace WaveHarmonic.Crest.Editor
                 return;
             }
 
-            message = $"Crest Validation: {message} {fixDescription} Click this message to highlight the problem object.";
+            // Always link back to the caller so developers know the origin. They can always
+            // use the help box "Inspect" once there to get to the object to fix. Even better,
+            // they can use any available fix buttons too.
+            var context = caller != null ? caller : @object;
+
+            message = $"<b>Crest Validation:</b> {message} {fixDescription} Click this message to highlight the problem object.";
 
             switch (type)
             {
-                case MessageType.Error: Debug.LogError(message, @object); break;
-                case MessageType.Warning: Debug.LogWarning(message, @object); break;
-                default: Debug.Log(message, @object); break;
+                case MessageType.Error: Debug.LogError(message, context); break;
+                case MessageType.Warning: Debug.LogWarning(message, context); break;
+                default: Debug.Log(message, context); break;
             }
         }
 
-        public static void HelpBox(string message, string fixDescription, MessageType type, Object @object = null, FixValidation action = null, string property = null)
+        public static void HelpBox(string message, string fixDescription, MessageType type, Object @object = null, FixValidation action = null, string property = null, Object caller = null)
         {
             s_Messages[(int)type].Add(new() { _Message = message, _FixDescription = fixDescription, _Object = @object, _Action = action, _PropertyPath = property });
         }
 
-        public static void Suppressed(string _0, string _1, MessageType _2, Object _3 = null, FixValidation _4 = null, string _5 = null)
+        public static void Suppressed(string _0, string _1, MessageType _2, Object _3 = null, FixValidation _4 = null, string _5 = null, Object _6 = null)
         {
         }
 
@@ -291,6 +297,24 @@ namespace WaveHarmonic.Crest.Editor
                 }
             }
 
+            // NOTE: Nested components do not descend from Object, but they could and this
+            // would work for them.
+            if (target is Object @object)
+            {
+                foreach (var field in TypeCache.GetFieldsWithAttribute<Validated>())
+                {
+                    if (field.DeclaringType != type)
+                    {
+                        continue;
+                    }
+
+                    foreach (var attribute in field.GetCustomAttributes<Validated>())
+                    {
+                        isValid &= attribute.Validate(@object, field, messenger);
+                    }
+                }
+            }
+
             return isValid;
         }
 
@@ -299,4 +323,89 @@ namespace WaveHarmonic.Crest.Editor
             return ExecuteValidators(target, DebugLog);
         }
     }
+
+    abstract class Validated : System.Attribute
+    {
+        public abstract bool Validate(Object target, FieldInfo property, ValidatedHelper.ShowMessage messenger);
+    }
+}
+
+namespace WaveHarmonic.Crest
+{
+    /// <summary>
+    /// Validates that field is not null.
+    /// </summary>
+    [System.AttributeUsage(System.AttributeTargets.Field, AllowMultiple = false)]
+    sealed class Required : Validated
+    {
+        public override bool Validate(Object target, FieldInfo field, ValidatedHelper.ShowMessage messenger)
+        {
+            var isValid = true;
+
+            if ((Object)field.GetValue(target) == null)
+            {
+                var typeName = EditorHelpers.Pretty(target.GetType().Name);
+                var fieldName = EditorHelpers.Pretty(field.Name);
+
+                messenger
+                (
+                    $"<i>{fieldName}</i> is required for the <i>{typeName}</i> component to function.",
+                    $"Please set <i>{fieldName}</i>.",
+                    ValidatedHelper.MessageType.Error,
+                    target
+                );
+
+                isValid = false;
+            }
+
+            return isValid;
+        }
+    }
+
+    /// <summary>
+    /// Shows a info message if field is null.
+    /// </summary>
+    [System.AttributeUsage(System.AttributeTargets.Field, AllowMultiple = false)]
+    sealed class Optional : Validated
+    {
+        readonly string _Message;
+
+        public Optional(string message)
+        {
+            _Message = message;
+        }
+
+        public override bool Validate(Object target, FieldInfo field, ValidatedHelper.ShowMessage messenger)
+        {
+            var value = field.GetValue(target);
+
+            if (value is ICollection<Object> list)
+            {
+                if (list != null && list.Count > 0)
+                {
+                    return true;
+                }
+            }
+            else
+            {
+                if (value is Object @object && @object != null)
+                {
+                    return true;
+                }
+            }
+
+            var typeName = EditorHelpers.Pretty(target.GetType().Name);
+            var fieldName = EditorHelpers.Pretty(field.Name);
+
+            messenger
+            (
+                $"<i>{fieldName}</i> is not set for the <i>{typeName}</i> component. " + _Message,
+                string.Empty,
+                ValidatedHelper.MessageType.Info,
+                target
+            );
+
+            return true;
+        }
+    }
 }