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

// Copyright UnexGames 2025. All Rights Reserved.
#pragma once
#include "CoreMinimal.h"
#include "ThreadTaskBase.h"
#include "HAL/ThreadManager.h"
#include "ThreadTasks.generated.h"

DECLARE_MULTICAST_DELEGATE(FThreadTaskDelegate);

UCLASS(HideDropdown, Blueprintable, hidecategories = (Object), meta = (DontUseGenericSpawnObject = "true"))
class MULTITHREADLIBRARY_API UThreadTasks : public UThreadTaskBase
{

	GENERATED_BODY()

public:

	virtual bool Start() override;

	/**
	* Called on Background Thread when the Task is executed.
	*/
	UFUNCTION(BlueprintNativeEvent, BlueprintCallable, meta = (DisplayName = "Task Body"), Category = "MultiThreadLibrary")
		void TaskBody();

	virtual void TaskBody_Implementation();

public:
	FThreadTaskDelegate TaskDelegate;

protected:


};


class MULTITHREADLIBRARY_API FThreadTaskOnly : public FTaskActionBase
{
	ETaskResultBranches& Branches;
	bool bStarted;
public:
	FThreadTaskOnly(UObject* InObject, ETaskResultBranches& InBranches, const FLatentActionInfo& LatentInfo, TSubclassOf<class UThreadTasks> TaskClass, UThreadBase*& OutTask)
		: FTaskActionBase(InObject, LatentInfo, TaskClass)
		, Branches(InBranches)
		, bStarted(false)
	{
		OutTask = Task;

		UThreadTasks* LocalTask = Cast<UThreadTasks>(Task);
		if (LocalTask)
		{
			Branches = ETaskResultBranches::OnStart;
			LocalTask->BodyFunction();

			bStarted = Task->Start();
		}
		else {
			return;
		}
	}


	virtual void UpdateOperation(FLatentResponse& Response) override
	{
		if (bStarted)
		{
			if (!IsCanceled())
			{
				if (!IsRunning())
				{
					Branches = ETaskResultBranches::OnCompleted;
					Response.FinishAndTriggerIf(true, ExecutionFunction, OutputLink, CallbackTarget);
				}
			}
			else
			{
				Branches = ETaskResultBranches::OnCanceled;
				Response.FinishAndTriggerIf(true, ExecutionFunction, OutputLink, CallbackTarget);
			}
		}
		else {
			//If we reached this point it means the task was unable to start.
			Branches = ETaskResultBranches::OnCompleted;
			Response.FinishAndTriggerIf(true, ExecutionFunction, OutputLink, CallbackTarget);
		}
	}
};

class MULTITHREADLIBRARY_API FThreadTaskWithBody : public FTaskActionBase
{
	EtaskExecutionBranches& Branches;
	bool bStarted;
public:
	FThreadTaskWithBody(UObject* InObject, EtaskExecutionBranches& InBranches, const FLatentActionInfo& LatentInfo, TSubclassOf<class UThreadTasks> TaskClass, const ETaskExecutionType& InExecutionType, UThreadBase*& OutTask)
		: FTaskActionBase(InObject, LatentInfo, TaskClass)
		, Branches(InBranches)
		, bStarted(false)
	{
		OutTask = Task;

		UThreadTasks* LocalTask = Cast<UThreadTasks>(Task);
		if (LocalTask)
		{
			Branches = EtaskExecutionBranches::OnStart;
			LocalTask->BodyFunction();

			LocalTask->TaskDelegate.AddLambda([LocalTask, &InBranches]
				{
					InBranches = EtaskExecutionBranches::OnTaskBody;
					LocalTask->BodyFunction();
				});
			LocalTask->OnCancelDelegate.AddLambda([LocalTask, &InBranches]
				{
					InBranches = EtaskExecutionBranches::OnCanceled;
					LocalTask->BodyFunction();
				});

			bStarted = Task->Start();
		}
		else {
			return;
		}
	}

	virtual ~FThreadTaskWithBody()
	{
		if (Task != nullptr && Task->IsValidLowLevel() && IsValid(Task) && !Task->IsUnreachable())
		{
			UThreadTasks* LocalTask = Cast<UThreadTasks>(Task);
			if (LocalTask)
			{
				LocalTask->TaskDelegate.RemoveAll(this);
				LocalTask->OnCancelDelegate.RemoveAll(this);
			}
		}
	}

	virtual void UpdateOperation(FLatentResponse& Response) override
	{
		if (bStarted)
		{
			if (!IsCanceled())
			{
				if (!IsRunning())
				{
					Branches = EtaskExecutionBranches::OnCompleted;
					Response.FinishAndTriggerIf(true, ExecutionFunction, OutputLink, CallbackTarget);
				}
			}
			else
			{
				Response.DoneIf(true);
			}
		}
		else {
			//If we reached this point it means the task was unable to start.
			Branches = EtaskExecutionBranches::OnCompleted;
			Response.FinishAndTriggerIf(true, ExecutionFunction, OutputLink, CallbackTarget);
		}
	}
};