October3d55/M/MultiThread/Source/MultiThreadLibrary/Public/ThreadBase.h

// Copyright UnexGames 2025. All Rights Reserved.
#pragma once

#include "CoreMinimal.h"
#include "UObject/Object.h"
#include "UObject/UObjectBaseUtility.h"
#include "LatentActions.h"
#include "Engine/LatentActionManager.h"
#include "Templates/SubclassOf.h"
#include "UObject/Package.h"
#include "ThreadUtility.h"
#include "ThreadBase.generated.h"

DECLARE_MULTICAST_DELEGATE(FTaskOnCancelDelegate);

UCLASS(HideDropdown, BlueprintType, hidecategories = (Object), meta = (DontUseGenericSpawnObject = "true"))
class MULTITHREADLIBRARY_API UThreadBase : public UObject
{
    GENERATED_BODY()

public:
    UThreadBase();
    ~UThreadBase();

    /**
    * Attempts to start the Task.
    * @return Return False if Task already running.
    */
    virtual bool Start();

    /**
    * Attempts to Cancel the Task.
    */
    virtual void Cancel();

    /**
    * Check whether the task is in progress.
    */
    virtual bool IsRunning();

    /**
    * Check whether the task is canceled.
    */
    virtual bool IsCanceled();

    /**
    * Called immediately on Game Thread when the Task is cancelled.
    */
    UFUNCTION(BlueprintNativeEvent, BlueprintCallable, meta = (DisplayName = "On Cancel"), Category = "MultiThreadLibrary")
        void OnCancel();
    virtual void OnCancel_Implementation();



    /**
    * Wait for work work to complete.
    */
        virtual void WaitToFinish();



    /**
    * Called immediately on Game Thread when the Task is completed.
    */
    UFUNCTION(BlueprintNativeEvent, BlueprintCallable, meta = (DisplayName = "On Complete"), Category = "MultiThreadLibrary")
        void OnComplete();
    virtual void OnComplete_Implementation();



public:
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "MultiThreadLibrary")
        bool bIsTickable = false;
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "MultiThreadLibrary")
        bool bIsTickableInEditor = false;
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "MultiThreadLibrary")
        bool bIsTickableWhenPaused = false;

    FTaskOnCancelDelegate OnCancelDelegate;
    TFunction<void()> BodyFunction;
protected:
    
    virtual UWorld* GetWorld() const override;

private:
    


protected:
    FThreadSafeBool bCanceled = false;

};


UENUM(BlueprintType)
enum class ETaskResultBranches : uint8
{
    OnStart,
    OnCompleted,
    OnCanceled,
};

UENUM(BlueprintType)
enum class EtaskExecutionBranches : uint8
{
    OnStart,
    OnTaskBody,
    OnCompleted,
    OnCanceled,
};

UENUM(BlueprintType)
enum class ETaskResultBranchesNoCancel : uint8
{
    OnStart,
    OnCompleted,
};

UENUM(BlueprintType)
enum class ETaskResultBranchesNoComplete : uint8
{
    OnStart,
    OnCanceled,
};

UENUM(BlueprintType)
enum class ETaskResultBranchesNoCompleteWithBody : uint8
{
    OnStart,
    OnTaskBody,
    OnCanceled,
};


class MULTITHREADLIBRARY_API FTaskActionBase : public FPendingLatentAction
{
protected:
    UObject* Object;
    FName ExecutionFunction;
    int32 OutputLink;
    FWeakObjectPtr CallbackTarget;
    UThreadBase* Task = nullptr;
public:
    FTaskActionBase(UObject* InObject, const FLatentActionInfo& LatentInfo, TSubclassOf<class UThreadBase> TaskClass)
        : Object(InObject)
        , ExecutionFunction(LatentInfo.ExecutionFunction)
        , OutputLink(LatentInfo.Linkage)
        , CallbackTarget(LatentInfo.CallbackTarget)
    {
        UThreadUtility::TaskIndex++;
        const FString Name = "Task Work" + FString::FromInt(UThreadUtility::TaskIndex);
        Task = NewObject<UThreadBase>(InObject, TaskClass, FName(*Name), RF_Transient);

        if (UObject* CallbackObject = CallbackTarget.Get())
        {
            if (UFunction* Function = CallbackObject->FindFunction(ExecutionFunction))
            {
                checkf(CallbackObject && Function, TEXT("Can't find Task Functions."));
                int32 LocalOutputLink = OutputLink;
                Task->BodyFunction = [CallbackObject, Function, LocalOutputLink]()
                {
                    int32 FinalOutputLink = LocalOutputLink;
                    if (CallbackObject && Function)
                    {
                        CallbackObject->ProcessEvent(Function, &(FinalOutputLink));
                    }
                };
            }
        }
    }

    virtual ~FTaskActionBase()
    {
        if (Task != nullptr && Task->IsValidLowLevel() && IsValid(Task) && !Task->IsUnreachable())
        {
            Task->Cancel();
        }
    }

    virtual bool IsRunning()
    {
        if (Task != nullptr && Task->IsValidLowLevel() && IsValid(Task) && !Task->IsUnreachable())
        {
            return Task->IsRunning();
        }
        return false;
    }

    virtual bool IsCanceled()
    {
        if (Task != nullptr && Task->IsValidLowLevel() && IsValid(Task) && !Task->IsUnreachable())
        {
            return Task->IsCanceled();
        }
        return true;
    }
};