void UChildActorComponent::CreateChildActor()
{
// Kill spawned actor if we have one
DestroyChildActor();
// This is no longer needed
if (CachedInstanceData)
{
delete CachedInstanceData;
CachedInstanceData = nullptr;
}
// If we have a class to spawn.
if(ChildActorClass != nullptr)
{
UWorld* World = GetWorld();
if(World != nullptr)
{
// Before we spawn let's try and prevent cyclic disaster
bool bSpawn = true;
AActor* Actor = GetOwner();
while (Actor && bSpawn)
{
if (Actor->GetClass() == ChildActorClass)
{
bSpawn = false;
UE_LOG(LogChildActorComponent, Error, TEXT("Found cycle in child actor component '%s'. Not spawning Actor of class '%s' to break."), *GetPathName(), *ChildActorClass->GetName());
}
Actor = Actor->ParentComponentActor.Get();
}
if (bSpawn)
{
FActorSpawnParameters Params;
Params.bNoCollisionFail = true;
Params.bDeferConstruction = true; // We defer construction so that we set ParentComponentActor prior to component registration so they appear selected
Params.bAllowDuringConstructionScript = true;
Params.OverrideLevel = GetOwner()->GetLevel();
Params.Name = ChildActorName;
if (!HasAllFlags(RF_Transactional))
{
Params.ObjectFlags &= ~RF_Transactional;
}
// Spawn actor of desired class
FVector Location = GetComponentLocation();
FRotator Rotation = GetComponentRotation();
ChildActor = World->SpawnActor(ChildActorClass, &Location, &Rotation, Params);
// If spawn was successful,
if(ChildActor != nullptr)
{
ChildActorName = ChildActor->GetFName();
// Remember which actor spawned it (for selection in editor etc)
ChildActor->ParentComponentActor = GetOwner();
ChildActor->AttachRootComponentTo(this);
// Parts that we deferred from SpawnActor
ChildActor->FinishSpawning(ComponentToWorld);
}
}
}
}
}
void UChildActorComponent::OnRegister()
{
Super::OnRegister();
if (ChildActor)
{
if (ChildActor->GetClass() != ChildActorClass)
{
DestroyChildActor();
CreateChildActor();
}
else
{
ChildActorName = ChildActor->GetFName();
USceneComponent* ChildRoot = ChildActor->GetRootComponent();
if (ChildRoot && ChildRoot->GetAttachParent() != this)
{
// attach new actor to this component
// we can't attach in CreateChildActor since it has intermediate Mobility set up
// causing spam with inconsistent mobility set up
// so moving Attach to happen in Register
ChildRoot->AttachToComponent(this, FAttachmentTransformRules::SnapToTargetNotIncludingScale);
}
// Ensure the components replication is correctly initialized
SetIsReplicated(ChildActor->GetIsReplicated());
}
}
else if (ChildActorClass)
{
CreateChildActor();
}
}
void UChildActorComponent::OnComponentDestroyed(bool bDestroyingHierarchy)
{
Super::OnComponentDestroyed(bDestroyingHierarchy);
const UWorld* const MyWorld = GetWorld();
DestroyChildActor(MyWorld && !MyWorld->IsGameWorld());
}
void UChildActorComponent::OnRegister()
{
Super::OnRegister();
if (ChildActor)
{
if (ChildActor->GetClass() != ChildActorClass)
{
DestroyChildActor();
CreateChildActor();
}
else
{
ChildActorName = ChildActor->GetFName();
USceneComponent* ChildRoot = ChildActor->GetRootComponent();
if (ChildRoot && ChildRoot->GetAttachParent() != this)
{
// attach new actor to this component
// we can't attach in CreateChildActor since it has intermediate Mobility set up
// causing spam with inconsistent mobility set up
// so moving Attach to happen in Register
ChildRoot->AttachTo(this, NAME_None, EAttachLocation::SnapToTarget);
}
}
}
else if (ChildActorClass)
{
CreateChildActor();
}
}
void UChildActorComponent::OnUnregister()
{
Super::OnUnregister();
const UWorld* const MyWorld = GetWorld();
DestroyChildActor(MyWorld && !MyWorld->IsGameWorld());
}
void UChildActorComponent::SetChildActorClass(TSubclassOf<AActor> Class)
{
ChildActorClass = Class;
if (IsRegistered())
{
DestroyChildActor();
CreateChildActor();
}
}
void UChildActorComponent::PostEditChangeProperty(FPropertyChangedEvent& PropertyChangedEvent)
{
Super::PostEditChangeProperty(PropertyChangedEvent);
static const FName NAME_ChildActorClass = GET_MEMBER_NAME_CHECKED(UChildActorComponent, ChildActorClass);
if (PropertyChangedEvent.Property && PropertyChangedEvent.Property->GetFName() == NAME_ChildActorClass)
{
DestroyChildActor();
CreateChildActor();
}
}
void UChildActorComponent::PostLoad()
{
Super::PostLoad();
// For a period of time the parent component property on Actor was not a UPROPERTY so this value was not set
if (ChildActor)
{
FActorParentComponentSetter::Set(ChildActor, this);
}
// Since the template could have been changed we need to respawn the child actor
// Don't do this if there is no linker which implies component was created via duplication
if (ChildActorTemplate && GetLinker())
{
DestroyChildActor();
}
}
void UChildActorComponent::PostEditChangeProperty(FPropertyChangedEvent& PropertyChangedEvent)
{
static const FName NAME_ChildActorClass = GET_MEMBER_NAME_CHECKED(UChildActorComponent, ChildActorClass);
if (PropertyChangedEvent.Property && PropertyChangedEvent.Property->GetFName() == NAME_ChildActorClass)
{
ChildActorName = NAME_None;
// If this was created by construction script, the post edit change super call will destroy it anyways
if (!IsCreatedByConstructionScript())
{
DestroyChildActor();
CreateChildActor();
}
}
Super::PostEditChangeProperty(PropertyChangedEvent);
}
void UChildActorComponent::PostEditChangeProperty(FPropertyChangedEvent& PropertyChangedEvent)
{
if (PropertyChangedEvent.Property && PropertyChangedEvent.Property->GetFName() == GET_MEMBER_NAME_CHECKED(UChildActorComponent, ChildActorClass))
{
ChildActorName = NAME_None;
if (!IsTemplate())
{
UChildActorComponent* Archetype = CastChecked<UChildActorComponent>(GetArchetype());
ChildActorTemplate = (Archetype->ChildActorClass == ChildActorClass ? Archetype->ChildActorTemplate : nullptr);
}
// If this was created by construction script, the post edit change super call will destroy it anyways
if (!IsCreatedByConstructionScript())
{
DestroyChildActor();
CreateChildActor();
}
}
Super::PostEditChangeProperty(PropertyChangedEvent);
}
void UChildActorComponent::OnUnregister()
{
Super::OnUnregister();
DestroyChildActor();
}
void UChildActorComponent::OnComponentDestroyed(bool bDestroyingHierarchy)
{
Super::OnComponentDestroyed(bDestroyingHierarchy);
DestroyChildActor();
}
void UChildActorComponent::OnComponentDestroyed()
{
Super::OnComponentDestroyed();
DestroyChildActor();
}
void UChildActorComponent::CreateChildActor()
{
// Kill spawned actor if we have one
DestroyChildActor();
// If we have a class to spawn.
if(ChildActorClass != nullptr)
{
UWorld* World = GetWorld();
if(World != nullptr)
{
// Before we spawn let's try and prevent cyclic disaster
bool bSpawn = true;
AActor* MyOwner = GetOwner();
AActor* Actor = MyOwner;
while (Actor && bSpawn)
{
if (Actor->GetClass() == ChildActorClass)
{
bSpawn = false;
UE_LOG(LogChildActorComponent, Error, TEXT("Found cycle in child actor component '%s'. Not spawning Actor of class '%s' to break."), *GetPathName(), *ChildActorClass->GetName());
}
if (UChildActorComponent* ParentComponent = Actor->GetParentComponent())
{
Actor = ParentComponent->GetOwner();
}
else
{
Actor = nullptr;
}
}
if (bSpawn)
{
FActorSpawnParameters Params;
Params.SpawnCollisionHandlingOverride = ESpawnActorCollisionHandlingMethod::AlwaysSpawn;
Params.bDeferConstruction = true; // We defer construction so that we set ParentComponent prior to component registration so they appear selected
Params.bAllowDuringConstructionScript = true;
Params.OverrideLevel = (MyOwner ? MyOwner->GetLevel() : nullptr);
Params.Name = ChildActorName;
if (!HasAllFlags(RF_Transactional))
{
Params.ObjectFlags &= ~RF_Transactional;
}
// Spawn actor of desired class
FVector Location = GetComponentLocation();
FRotator Rotation = GetComponentRotation();
ChildActor = World->SpawnActor(ChildActorClass, &Location, &Rotation, Params);
// If spawn was successful,
if(ChildActor != nullptr)
{
ChildActorName = ChildActor->GetFName();
// Remember which component spawned it (for selection in editor etc)
FActorParentComponentSetter::Set(ChildActor, this);
// Parts that we deferred from SpawnActor
const FComponentInstanceDataCache* ComponentInstanceData = (CachedInstanceData ? CachedInstanceData->ComponentInstanceData : nullptr);
ChildActor->FinishSpawning(ComponentToWorld, false, ComponentInstanceData);
ChildActor->AttachRootComponentTo(this, NAME_None, EAttachLocation::SnapToTarget);
}
}
}
}
// This is no longer needed
if (CachedInstanceData)
{
delete CachedInstanceData;
CachedInstanceData = nullptr;
}
}
void UChildActorComponent::CreateChildActor()
{
AActor* MyOwner = GetOwner();
if (MyOwner && !MyOwner->HasAuthority())
{
AActor* ChildClassCDO = (ChildActorClass ? ChildActorClass->GetDefaultObject<AActor>() : nullptr);
if (ChildClassCDO && ChildClassCDO->GetIsReplicated())
{
// If we belong to an actor that is not authoritative and the child class is replicated then we expect that Actor will be replicated across so don't spawn one
return;
}
}
// Kill spawned actor if we have one
DestroyChildActor();
// If we have a class to spawn.
if(ChildActorClass != nullptr)
{
UWorld* World = GetWorld();
if(World != nullptr)
{
// Before we spawn let's try and prevent cyclic disaster
bool bSpawn = true;
AActor* Actor = MyOwner;
while (Actor && bSpawn)
{
if (Actor->GetClass() == ChildActorClass)
{
bSpawn = false;
UE_LOG(LogChildActorComponent, Error, TEXT("Found cycle in child actor component '%s'. Not spawning Actor of class '%s' to break."), *GetPathName(), *ChildActorClass->GetName());
}
Actor = Actor->GetParentActor();
}
if (bSpawn)
{
FActorSpawnParameters Params;
Params.SpawnCollisionHandlingOverride = ESpawnActorCollisionHandlingMethod::AlwaysSpawn;
Params.bDeferConstruction = true; // We defer construction so that we set ParentComponent prior to component registration so they appear selected
Params.bAllowDuringConstructionScript = true;
Params.OverrideLevel = (MyOwner ? MyOwner->GetLevel() : nullptr);
Params.Name = ChildActorName;
Params.Template = ChildActorTemplate;
if (!HasAllFlags(RF_Transactional))
{
Params.ObjectFlags &= ~RF_Transactional;
}
// Spawn actor of desired class
ConditionalUpdateComponentToWorld();
FVector Location = GetComponentLocation();
FRotator Rotation = GetComponentRotation();
ChildActor = World->SpawnActor(ChildActorClass, &Location, &Rotation, Params);
// If spawn was successful,
if(ChildActor != nullptr)
{
ChildActorName = ChildActor->GetFName();
// Remember which component spawned it (for selection in editor etc)
FActorParentComponentSetter::Set(ChildActor, this);
// Parts that we deferred from SpawnActor
const FComponentInstanceDataCache* ComponentInstanceData = (CachedInstanceData ? CachedInstanceData->ComponentInstanceData : nullptr);
ChildActor->FinishSpawning(ComponentToWorld, false, ComponentInstanceData);
ChildActor->AttachToComponent(this, FAttachmentTransformRules::SnapToTargetNotIncludingScale);
SetIsReplicated(ChildActor->GetIsReplicated());
}
}
}
}
// This is no longer needed
if (CachedInstanceData)
{
delete CachedInstanceData;
CachedInstanceData = nullptr;
}
}
