bool FComponentKey::RefreshVariableName()
{
	if (IsValid() && IsSCSKey())
	{
		USCS_Node* SCSNode = FindSCSNode();
		const FName UpdatedName = SCSNode ? SCSNode->GetVariableName() : NAME_None;

		if (UpdatedName != SCSVariableName)
		{
			SCSVariableName = UpdatedName;
			return true;
		}
	}
	return false;
}
void USimpleConstructionScript::FixupRootNodeParentReferences()
{
	// Get the BlueprintGeneratedClass that owns the SCS
	UClass* BPGeneratedClass = GetOwnerClass();
	if(BPGeneratedClass == NULL)
	{
		UE_LOG(LogBlueprint, Warning, TEXT("USimpleConstructionScript::FixupRootNodeParentReferences() - owner class is NULL; skipping."));
		// cannot do the rest of fixup without a BPGC
		return;
	}

	for (int32 NodeIndex=0; NodeIndex < RootNodes.Num(); ++NodeIndex)
	{
		// If this root node is parented to a native/inherited component template
		USCS_Node* RootNode = RootNodes[NodeIndex];
		if(RootNode->ParentComponentOrVariableName != NAME_None)
		{
			bool bWasFound = false;

			// If the node is parented to a native component
			if(RootNode->bIsParentComponentNative)
			{
				// Get the Blueprint class default object
				AActor* CDO = Cast<AActor>(BPGeneratedClass->GetDefaultObject(false));
				if(CDO != NULL)
				{
					// Look for the parent component in the CDO's components array
					TInlineComponentArray<UActorComponent*> Components;
					CDO->GetComponents(Components);

					for (auto CompIter = Components.CreateConstIterator(); CompIter && !bWasFound; ++CompIter)
					{
						UActorComponent* ComponentTemplate = *CompIter;
						bWasFound = ComponentTemplate->GetFName() == RootNode->ParentComponentOrVariableName;
					}
				}
				else 
				{ 
					// SCS and BGClass depends on each other (while their construction).
					// Class is not ready, so one have to break the dependency circle.
					continue;
				}
			}
			// Otherwise the node is parented to an inherited SCS node from a parent Blueprint
			else
			{
				// Get the Blueprint hierarchy
				TArray<const UBlueprintGeneratedClass*> ParentBPClassStack;
				const bool bErrorFree = UBlueprintGeneratedClass::GetGeneratedClassesHierarchy(BPGeneratedClass, ParentBPClassStack);

				// Find the parent Blueprint in the hierarchy
				for(int32 StackIndex = ParentBPClassStack.Num() - 1; StackIndex > 0; --StackIndex)
				{
					const UBlueprintGeneratedClass* ParentClass = ParentBPClassStack[StackIndex];
					if( ParentClass != NULL
						&& ParentClass->SimpleConstructionScript != NULL
						&& ParentClass->GetFName() == RootNode->ParentComponentOwnerClassName)
					{
						// Attempt to locate a match by searching all the nodes that belong to the parent Blueprint's SCS
						for (USCS_Node* ParentNode : ParentClass->SimpleConstructionScript->GetAllNodes())
						{
							if (ParentNode != nullptr && ParentNode->VariableName == RootNode->ParentComponentOrVariableName)
							{
								bWasFound = true;
								break;
							}
						}

						// We found a match; no need to continue searching the hierarchy
						break;
					}
				}
			}

			// Clear parent info if we couldn't find the parent component instance
			if(!bWasFound)
			{
				UE_LOG(LogBlueprint, Warning, TEXT("USimpleConstructionScript::FixupRootNodeParentReferences() - Couldn't find %s parent component '%s' for '%s' in BlueprintGeneratedClass '%s' (it may have been removed)"), RootNode->bIsParentComponentNative ? TEXT("native") : TEXT("inherited"), *RootNode->ParentComponentOrVariableName.ToString(), *RootNode->GetVariableName().ToString(), *BPGeneratedClass->GetName());

				RootNode->bIsParentComponentNative = false;
				RootNode->ParentComponentOrVariableName = NAME_None;
				RootNode->ParentComponentOwnerClassName = NAME_None;
			}
		}
	}

	// call this after we do the above ParentComponentOrVariableName fixup, 
	// because this operates differently for root nodes that have their 
	// ParentComponentOrVariableName field cleared
	//
	// repairs invalid scene hierarchies (like when this Blueprint has been 
	// reparented and there is no longer an inherited scene root... meaning one
	// of the scene component nodes here needs to be promoted)
	FixupSceneNodeHierarchy();
}
void USimpleConstructionScript::PostLoad()
{
	Super::PostLoad();

	int32 NodeIndex;
	TArray<USCS_Node*> Nodes = GetAllNodes();

#if WITH_EDITOR
	// Get the Blueprint that owns the SCS
	UBlueprint* Blueprint = GetBlueprint();
	if (!Blueprint)
	{
		// sometimes the PostLoad can be called, after the object was trashed, we dont want this
		UE_LOG(LogBlueprint, Warning, TEXT("USimpleConstructionScript::PostLoad() '%s' cannot find its owner blueprint"), *GetPathName());
		return;
	}

	for (NodeIndex=0; NodeIndex < Nodes.Num(); ++NodeIndex)
	{
		USCS_Node* Node = Nodes[NodeIndex];

		// Fix up any uninitialized category names
		if(Node->CategoryName == NAME_None)
		{
			Node->CategoryName = TEXT("Default");
		}

		// Fix up components that may have switched from scene to non-scene type and vice-versa
		if(Node->ComponentTemplate != nullptr)
		{
			// Check to see if switched from scene to a non-scene component type
			if (!Node->ComponentTemplate->IsA<USceneComponent>())
			{
				// Otherwise, check to see if switched from scene to non-scene component type
				int32 RootNodeIndex = INDEX_NONE;
				if(!RootNodes.Find(Node, RootNodeIndex))
				{
					// Move the node into the root set if it's currently in the scene hierarchy
					USCS_Node* ParentNode = FindParentNode(Node);
					if(ParentNode != nullptr)
					{
						ParentNode->ChildNodes.Remove(Node);
					}

					RootNodes.Add(Node);
				}
				else
				{
					// Otherwise, if it's a root node, promote one of its children (if any) to take its place
					int32 PromoteIndex = FindPromotableChildNodeIndex(Node);
					if(PromoteIndex != INDEX_NONE)
					{
						// Remove it as a child node
						USCS_Node* ChildToPromote = Node->ChildNodes[PromoteIndex];
						Node->ChildNodes.RemoveAt(PromoteIndex);

						// Insert it as a root node just before its prior parent node; this way if it switches back to a scene type it won't supplant the new root we've just created
						RootNodes.Insert(ChildToPromote, RootNodeIndex);

						// Append previous root node's children to the new root
						ChildToPromote->ChildNodes.Append(Node->ChildNodes);

						// Clear all child nodes from the old root (because it's now a non-scene type and no longer supports attached components)
						Node->ChildNodes.Empty();

						// Copy any previous external attachment info from the previous root node
						ChildToPromote->bIsParentComponentNative = Node->bIsParentComponentNative;
						ChildToPromote->ParentComponentOrVariableName = Node->ParentComponentOrVariableName;
						ChildToPromote->ParentComponentOwnerClassName = Node->ParentComponentOwnerClassName;
					}

					// Clear info for any previous external attachment if set
					if(Node->ParentComponentOrVariableName != NAME_None)
					{
						Node->bIsParentComponentNative = false;
						Node->ParentComponentOrVariableName = NAME_None;
						Node->ParentComponentOwnerClassName = NAME_None;
					}
				}
			}
		}
	}
#endif // WITH_EDITOR

	// Fix up native/inherited parent attachments, in case anything has changed
	FixupRootNodeParentReferences();

	// Ensure that we have a valid scene root
	ValidateSceneRootNodes();

	// Reset non-native "root" scene component scale values, prior to the change in which
	// we began applying custom scale values to root components at construction time. This
	// way older, existing Blueprint actor instances won't start unexpectedly getting scaled.
	if(GetLinkerUE4Version() < VER_UE4_BLUEPRINT_USE_SCS_ROOTCOMPONENT_SCALE)
	{
		// Get the BlueprintGeneratedClass that owns the SCS
		UClass* BPGeneratedClass = GetOwnerClass();
		if(BPGeneratedClass != nullptr)
		{
			// Get the Blueprint class default object
			AActor* CDO = Cast<AActor>(BPGeneratedClass->GetDefaultObject(false));
			if(CDO != NULL)
			{
				// Check for a native root component
				USceneComponent* NativeRootComponent = CDO->GetRootComponent();
				if(NativeRootComponent == nullptr)
				{
					// If no native root component exists, find the first non-native, non-parented SCS node with a
					// scene component template. This will be designated as the root component at construction time.
					for(NodeIndex = 0; NodeIndex < RootNodes.Num(); ++NodeIndex)
					{
						USCS_Node* Node = RootNodes[NodeIndex];
						if(Node->ParentComponentOrVariableName == NAME_None)
						{
							// Note that we have to check for nullptr here, because it may be an ActorComponent type
							USceneComponent* SceneComponentTemplate = Cast<USceneComponent>(Node->ComponentTemplate);
							if(SceneComponentTemplate != nullptr
								&& SceneComponentTemplate->RelativeScale3D != FVector(1.0f, 1.0f, 1.0f))
							{
								UE_LOG(LogBlueprint, Warning, TEXT("%s: Found non-native root component custom scale for %s (%s) saved prior to being usable; reverting to default scale."), *BPGeneratedClass->GetName(), *Node->GetVariableName().ToString(), *SceneComponentTemplate->RelativeScale3D.ToString());
								SceneComponentTemplate->RelativeScale3D = FVector(1.0f, 1.0f, 1.0f);
							}

							// Done - no need to fix up any other nodes.
							break;
						}
					}
				}
			}
		}
	}
}