FQuickTweenLatentAction.h

// Copyright 2025 Juan Pablo Hernandez Mosti. All Rights Reserved.
 
#pragma once
 
#include "CoreMinimal.h"
#include "LatentActions.h"
#include "Engine/LatentActionManager.h"
#include "FQuickTweenLatentAction.generated.h"
 
struct FLatentResponse;

UENUM()
enum class EQuickTweenLatentSteps : uint8
{
    Default,
    OnStart,
    OnUpdate,
    OnLoop,
    OnComplete,
    OnKilled
};

class FQuickTweenLatentAction : public FPendingLatentAction
{
public:
    template<typename T>
    FQuickTweenLatentAction(const FLatentActionInfo& latentInfo, T* tweenObj, EQuickTweenLatentSteps& outLatentStep);

    virtual void UpdateOperation(FLatentResponse& Response) override;
 
private:
    FName ExecutionFunction;

    int32 OutputLink;

    FWeakObjectPtr CallbackTarget;

    bool bIsFirstUpdate;

    EQuickTweenLatentSteps* StepPtr = nullptr;

    TArray<EQuickTweenLatentSteps> Buffer;

    void HandleStep(EQuickTweenLatentSteps NewStep);
};
 
template <typename T>
FQuickTweenLatentAction::FQuickTweenLatentAction(
    const FLatentActionInfo& latentInfo,
    T* tweenObj,
    EQuickTweenLatentSteps& outLatentStep)
    :   ExecutionFunction(latentInfo.ExecutionFunction),
        OutputLink(latentInfo.Linkage),
        CallbackTarget(latentInfo.CallbackTarget),
        bIsFirstUpdate(true),
        StepPtr(&outLatentStep)
{
    Buffer.Reserve(50);
 
    HandleStep(EQuickTweenLatentSteps::Default);
 
    tweenObj->OnStart.AddLambda([this](T*)
    {
        HandleStep(EQuickTweenLatentSteps::OnStart);
    });
 
    tweenObj->OnUpdate.AddLambda([this](T*)
    {
        HandleStep(EQuickTweenLatentSteps::OnUpdate);
    });
 
    tweenObj->OnComplete.AddLambda([this](T*)
    {
        HandleStep(EQuickTweenLatentSteps::OnComplete);
    });
 
    tweenObj->OnKilled.AddLambda([this](T*)
    {
        HandleStep(EQuickTweenLatentSteps::OnKilled);
    });
 
    tweenObj->OnLoop.AddLambda([this](T*)
    {
        HandleStep(EQuickTweenLatentSteps::OnLoop);
    });
}