Fix creating prefabs directly from prefab objects

#1432

Source/Editor/Modules/PrefabsModule.cs

@@ -37,11 +37,6 @@ namespace FlaxEditor.Modules
         /// </summary>
         public event Action<Prefab, Actor> PrefabApplied;
 
-        /// <summary>
-        /// Locally cached actor for prefab creation.
-        /// </summary>
-        private Actor _prefabCreationActor;
-
         internal PrefabsModule(Editor editor)
         : base(editor)
         {
@@ -65,13 +60,14 @@ namespace FlaxEditor.Modules
         /// To create prefab manually (from code) use <see cref="PrefabManager.CreatePrefab"/> method.
         /// </remarks>
         /// <param name="selection">The scene selection to use.</param>
-        public void CreatePrefab(List<SceneGraphNode> selection)
+        /// <param name="prefabWindow">The prefab window that creates it.</param>
+        public void CreatePrefab(List<SceneGraphNode> selection, Windows.Assets.PrefabWindow prefabWindow = null)
         {
             if (selection == null)
                 selection = Editor.SceneEditing.Selection;
             if (selection.Count == 1 && selection[0] is ActorNode actorNode && actorNode.CanCreatePrefab)
             {
-                CreatePrefab(actorNode.Actor);
+                CreatePrefab(actorNode.Actor, true, prefabWindow);
             }
         }
 
@@ -92,7 +88,8 @@ namespace FlaxEditor.Modules
         /// </summary>
         /// <param name="actor">The root prefab actor.</param>
         /// <param name="rename">Allow renaming or not</param>
-        public void CreatePrefab(Actor actor, bool rename)
+        /// <param name="prefabWindow">The prefab window that creates it.</param>
+        public void CreatePrefab(Actor actor, bool rename, Windows.Assets.PrefabWindow prefabWindow = null)
         {
             // Skip in invalid states
             if (!Editor.StateMachine.CurrentState.CanEditContent)
@@ -105,42 +102,47 @@ namespace FlaxEditor.Modules
             PrefabCreating?.Invoke(actor);
 
             var proxy = Editor.ContentDatabase.GetProxy<Prefab>();
-            _prefabCreationActor = actor;
-            Editor.Windows.ContentWin.NewItem(proxy, actor, OnPrefabCreated, actor.Name, rename);
+            Editor.Windows.ContentWin.NewItem(proxy, actor, contentItem => OnPrefabCreated(contentItem, actor, prefabWindow), actor.Name, rename);
         }
 
-        private void OnPrefabCreated(ContentItem contentItem)
+        private void OnPrefabCreated(ContentItem contentItem, Actor actor, Windows.Assets.PrefabWindow prefabWindow)
         {
             if (contentItem is PrefabItem prefabItem)
             {
                 PrefabCreated?.Invoke(prefabItem);
             }
 
-            // Skip in invalid states
-            if (!Editor.StateMachine.CurrentState.CanEditScene)
-                return;
+            Undo undo = null;
+            if (prefabWindow != null)
+            {
+                prefabWindow.MarkAsEdited();
+                undo = prefabWindow.Undo;
+            }
+            else
+            {
+                // Skip in invalid states
+                if (!Editor.StateMachine.CurrentState.CanEditScene)
+                    return;
+                undo = Editor.Undo;
+            }
 
             // Record undo for prefab creating (backend links the target instance with the prefab)
-            if (Editor.Undo.Enabled)
+            if (undo.Enabled)
             {
-                if (!_prefabCreationActor)
+                if (!actor)
                     return;
-
                 var actorsList = new List<Actor>();
-                Utilities.Utils.GetActorsTree(actorsList, _prefabCreationActor);
+                Utilities.Utils.GetActorsTree(actorsList, actor);
                 
                 var actions = new IUndoAction[actorsList.Count];
                 for (int i = 0; i < actorsList.Count; i++)
-                {
-                    var action = BreakPrefabLinkAction.Linked(actorsList[i]);
-                    actions[i] = action;
-                }
-                Undo.AddAction(new MultiUndoAction(actions));
-
-                _prefabCreationActor = null;
+                    actions[i] = BreakPrefabLinkAction.Linked(actorsList[i]);
+                undo.AddAction(new MultiUndoAction(actions));
             }
 
-            Editor.Instance.Windows.PropertiesWin.Presenter.BuildLayout();
+            Editor.Windows.PropertiesWin.Presenter.BuildLayout();
+            if (prefabWindow != null)
+                prefabWindow.Presenter.BuildLayout();
         }
 
         /// <summary>

Source/Editor/Windows/Assets/PrefabWindow.Hierarchy.cs

@@ -233,7 +233,7 @@ namespace FlaxEditor.Windows.Assets
 
             contextMenu.AddSeparator();
 
-            b = contextMenu.AddButton("Create Prefab", () => Editor.Prefabs.CreatePrefab(Selection));
+            b = contextMenu.AddButton("Create Prefab", () => Editor.Prefabs.CreatePrefab(Selection, this));
             b.Enabled = isSingleActorSelected &&
                         (Selection[0] as ActorNode).CanCreatePrefab &&
                         Editor.Windows.ContentWin.CurrentViewFolder.CanHaveAssets;

Source/Editor/Windows/Assets/PrefabWindow.cs

@@ -53,6 +53,11 @@ namespace FlaxEditor.Windows.Assets
         /// </summary>
         public PrefabWindowViewport Viewport => _viewport;
 
+        /// <summary>
+        /// Gets the prefab objects properties editor.
+        /// </summary>
+        public CustomEditorPresenter Presenter => _propertiesEditor;
+
         /// <summary>
         /// Gets the undo system used by this window for changes tracking.
         /// </summary>

Source/Engine/Level/Prefabs/PrefabManager.cpp

@@ -321,6 +321,8 @@ bool PrefabManager::CreatePrefab(Actor* targetActor, const StringView& outputPat
     // Serialize to json data
     ASSERT(!IsCreatingPrefab);
     IsCreatingPrefab = true;
+    const Guid targetPrefabId = targetActor->GetPrefabID();
+    const bool hasTargetPrefabId = targetPrefabId.IsValid();
     rapidjson_flax::StringBuffer actorsDataBuffer;
     {
         CompactJsonWriter writerObj(actorsDataBuffer);
@@ -329,7 +331,27 @@ bool PrefabManager::CreatePrefab(Actor* targetActor, const StringView& outputPat
         for (int32 i = 0; i < sceneObjects->Count(); i++)
         {
             SceneObject* obj = sceneObjects->At(i);
+
+            // Detect when creating prefab from object that is already part of prefab then serialize it as unlinked
+            const Guid prefabId = obj->GetPrefabID();
+            const Guid prefabObjectId = obj->GetPrefabObjectID();
+            bool isObjectFromPrefab = targetPrefabId == prefabId && prefabId.IsValid(); // Allow to use other nested prefabs properly (ignore only root object's prefab link)
+            if (isObjectFromPrefab)
+            {
+                //obj->BreakPrefabLink();
+                obj->_prefabID = Guid::Empty;
+                obj->_prefabObjectID = Guid::Empty;
+            }
+
             writer.SceneObject(obj);
+
+            // Restore broken link
+            if (hasTargetPrefabId)
+            {
+                //obj->LinkPrefab(prefabId, prefabObjectId);
+                obj->_prefabID = prefabId;
+                obj->_prefabObjectID = prefabObjectId;
+            }
         }
         writer.EndArray();
     }
@@ -395,7 +417,6 @@ bool PrefabManager::CreatePrefab(Actor* targetActor, const StringView& outputPat
         {
             SceneObject* obj = sceneObjects->At(i);
             Guid prefabObjectId;
-
             if (objectInstanceIdToPrefabObjectId.TryGet(obj->GetSceneObjectId(), prefabObjectId))
             {
                 obj->LinkPrefab(assetInfo.ID, prefabObjectId);

Source/Engine/Serialization/JsonTools.cpp

@@ -81,7 +81,6 @@ void JsonTools::ChangeIds(Document& doc, const Dictionary<Guid, Guid>& mapping)
     ::ChangeIds(doc, doc, mapping);
 }
 
-
 Float2 JsonTools::GetFloat2(const Value& value)
 {
     Float2 result;