UnrealEngineUWP/Engine/Plugins/Runtime/StateTree/Source/StateTreeModule/Public/Blueprint/StateTreeNodeBlueprintBase.h

// Copyright Epic Games, Inc. All Rights Reserved.

#pragma once

#include "StateTreeTypes.h"
#include "StateTreeEvents.h"
#include "StateTreeNodeBlueprintBase.generated.h"

struct FStateTreeLinker;
struct FStateTreeExecutionContext;

UENUM()
enum class EStateTreeBlueprintPropertyCategory : uint8
{
	NotSet,
	Input,	
	Parameter,
	Output,
	ContextObject,
};


/** Struct use to copy external data to the Blueprint item instance, resolved during StateTree linking. */
struct STATETREEMODULE_API FStateTreeBlueprintExternalDataHandle
{
	const FProperty* Property = nullptr;
	FStateTreeExternalDataHandle Handle;
};


UCLASS(Abstract)
class STATETREEMODULE_API UStateTreeNodeBlueprintBase : public UObject
{
	GENERATED_BODY()

public:
	/** Sends event to the StateTree */
	UFUNCTION(BlueprintCallable, Category = "StateTree", meta = (HideSelfPin = "true", DisplayName = "StateTree Send Event"))
	void SendEvent(const FStateTreeEvent& Event);
	
protected:
	virtual UWorld* GetWorld() const override;
	AActor* GetOwnerActor(const FStateTreeExecutionContext& Context) const;

	struct FScopedCurrentContext
	{
		FScopedCurrentContext(const UStateTreeNodeBlueprintBase& InNode, FStateTreeExecutionContext& Context) :
			Node(InNode)
		{
			Node.CurrentContext = &Context;
		}

		~FScopedCurrentContext()
		{
			Node.CurrentContext = nullptr;
		}
		const UStateTreeNodeBlueprintBase& Node;
	};
	
	/** Cached execution context during Tick() and other functions. */
	mutable FStateTreeExecutionContext* CurrentContext = nullptr;
};