ExternalDataLayerEngineSubsystem.h

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// Copyright Epic Games, Inc. All Rights Reserved.
#pragma once
 
#include "CoreFwd.h"
#include "UObject/ObjectMacros.h"
#include "UObject/ObjectKey.h"
#include "Templates/SubclassOf.h"
#include "Subsystems/EngineSubsystem.h"
#include "Tickable.h"
#include "WorldPartition/DataLayer/ExternalDataLayerInjectionPolicy.h"
 
#include "ExternalDataLayerEngineSubsystem.generated.h"
 
struct FAssetData;
class UExternalDataLayerAsset;
 
enum class EExternalDataLayerRegistrationState : uint8
{
    Unregistered,
    Registered,
    Active
};
 
UCLASS(Config = Engine, MinimalAPI)
class UExternalDataLayerEngineSubsystem : public UEngineSubsystem, public FTickableGameObject
{
    GENERATED_BODY()
 
public:
    ENGINE_API static UExternalDataLayerEngineSubsystem& Get();
 
#if WITH_EDITOR
    ENGINE_API virtual void Initialize(FSubsystemCollectionBase& Collection) override;
    ENGINE_API virtual void Deinitialize() override;
 
    virtual bool IsTickableInEditor() const override { return true; }
    virtual UWorld* GetTickableGameObjectWorld() const override;
#endif
    virtual bool IsTickable() const override;
    virtual void Tick(float DeltaTime) override;
    virtual ETickableTickType GetTickableTickType() const override { return (IsTemplate() ? ETickableTickType::Never : ETickableTickType::Conditional); }
    virtual TStatId GetStatId() const override;
 
    ENGINE_API void RegisterExternalDataLayerAsset(const UExternalDataLayerAsset* InExternalDataLayerAsset, const UObject* InClient);
    ENGINE_API void UnregisterExternalDataLayerAsset(const UExternalDataLayerAsset* InExternalDataLayerAsset, const UObject* InClient);
    ENGINE_API void ActivateExternalDataLayerAsset(const UExternalDataLayerAsset* InExternalDataLayerAsset, const UObject* InClient);
    ENGINE_API void DeactivateExternalDataLayerAsset(const UExternalDataLayerAsset* InExternalDataLayerAsset, const UObject* InClient);
    ENGINE_API bool IsExternalDataLayerAssetRegistered(const UExternalDataLayerAsset* InExternalDataLayerAsset, const UObject* InClient = nullptr) const;
    ENGINE_API bool IsExternalDataLayerAssetActive(const UExternalDataLayerAsset* InExternalDataLayerAsset, const UObject* InClient = nullptr) const;
    ENGINE_API EExternalDataLayerRegistrationState GetExternalDataLayerAssetRegistrationState(const UExternalDataLayerAsset* InExternalDataLayerAsset) const;
    ENGINE_API TArray<UObject*> GetClientsForExternalDataLayerAsset(const UExternalDataLayerAsset* InExternalDataLayerAsset) const;
 
    DECLARE_MULTICAST_DELEGATE_ThreeParams(FExternalDataLayerAssetRegistrationStateChangedEventDelegate, const UExternalDataLayerAsset* ExternalDataLayerAsset, EExternalDataLayerRegistrationState OldState, EExternalDataLayerRegistrationState NewState);
    FExternalDataLayerAssetRegistrationStateChangedEventDelegate OnExternalDataLayerAssetRegistrationStateChanged;
 
    DECLARE_MULTICAST_DELEGATE_ThreeParams(FExternalDataLayerOverrideInjectionDelegate, const UWorld* InWorld, const UExternalDataLayerAsset* InExternalDataLayerAsset, bool& bOutOverrideValue);
    FExternalDataLayerOverrideInjectionDelegate OnExternalDataLayerOverrideInjection;
    ENGINE_API bool CanInjectOverride(const UWorld* InWorld, const UExternalDataLayerAsset* InExternalDataLayerAsset, bool& bOutOverrideValue) const;
 
private:
#if WITH_EDITOR
    void OnAssetsPreDelete(const TArray<UObject*>& Objects);
    void OnGetLevelExternalActorsPaths(const FString& InLevelPackageName, const FString& InPackageShortName, TArray<FString>& OutExternalActorsPaths);
    bool OnResolveLevelMountPoint(const FString& InLevelPackageName, const UObject* InLevelMountPointContext, FString& OutResolvedLevelMountPoint);
#endif
    ENGINE_API bool CanWorldInjectExternalDataLayerAsset(const UWorld* InWorld, const UExternalDataLayerAsset* InExternalDataLayerAsset, FText* OutFailureReason = nullptr) const;
 
#if WITH_EDITORONLY_DATA
    UPROPERTY(Config)
    TSubclassOf<UExternalDataLayerInjectionPolicy> InjectionPolicyClass;
 
    UPROPERTY(Transient)
    TObjectPtr<UExternalDataLayerInjectionPolicy> InjectionPolicy;
#endif
 
    struct FRegisteredExternalDataLayers
    {
        TSet<FObjectKey> RegisteredClients;
        TSet<FObjectKey> ActiveClients;
        EExternalDataLayerRegistrationState State = EExternalDataLayerRegistrationState::Registered;
    };
 
    using FRegisteredExternalDataLayerAssetMap = TMap<TObjectPtr<const UExternalDataLayerAsset>, FRegisteredExternalDataLayers>;
    const FRegisteredExternalDataLayerAssetMap& GetRegisteredExternalDataLayerAssets() const { return ExternalDataLayerAssets; }
 
    FRegisteredExternalDataLayerAssetMap ExternalDataLayerAssets;
 
#if WITH_EDITOR
    TMap<TWeakObjectPtr<const UExternalDataLayerAsset>, FRegisteredExternalDataLayers> PreDeletedExternalDataLayerAssets;
 
    using FForcedExternalDataLayerInjectionKey = TPair<const UWorld*, const UExternalDataLayerAsset*>;
    TSet<FForcedExternalDataLayerInjectionKey> ForcedAllowInjection;
 
    FDelegateHandle LevelExternalActorsPathsProviderDelegateHandle;
    FDelegateHandle LevelMountPointResolverDelegateHandle;
#endif
 
    friend class UExternalDataLayerManager;
    friend class UGameFeatureActionConvertContentBundleWorldPartitionBuilder;
};