[visualstudio][cpp][UE5]UE5 Logic Nightで話題になったイベントディスパッチャーとデリゲートに関する調べものvol.02エンジンソースで見つけたUnrealEngine C++のデリゲート Oculus の例

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

#pragma once

#include "UObject/Object.h"
#include "Net/OnlineBlueprintCallProxyBase.h"
#include "Interfaces/OnlineSessionInterface.h"
#include "FindSessionsCallbackProxy.h"
#include "OculusFindSessionsCallbackProxy.generated.h"

/**
 * Exposes FindSession of the Platform SDK for blueprint use.
 */
UCLASS(MinimalAPI)
class UOculusFindSessionsCallbackProxy : public UOnlineBlueprintCallProxyBase
{
	GENERATED_UCLASS_BODY()

	// Called when there is a successful query
	UPROPERTY(BlueprintAssignable)
	FBlueprintFindSessionsResultDelegate OnSuccess;

	// Called when there is an unsuccessful query
	UPROPERTY(BlueprintAssignable)
	FBlueprintFindSessionsResultDelegate OnFailure;

	// Searches for matchmaking room sessions with the oculus online subsystem
	UFUNCTION(BlueprintCallable, Category = "Oculus|Session", meta = (BlueprintInternalUseOnly = "true"))
	static UOculusFindSessionsCallbackProxy* FindMatchmakingSessions(int32 MaxResults, FString OculusMatchmakingPool);

	// Searches for moderated room sessions with the oculus online subsystem
	UFUNCTION(BlueprintCallable, Category = "Oculus|Session", meta = (BlueprintInternalUseOnly = "true"))
	static UOculusFindSessionsCallbackProxy* FindModeratedSessions(int32 MaxResults);

	// UOnlineBlueprintCallProxyBase interface
	virtual void Activate() override;
	// End of UOnlineBlueprintCallProxyBase interface

private:
	// Internal callback when the session search completes, calls out to the public success/failure callbacks
	void OnCompleted(bool bSuccess);

private:

	// The delegate executed by the online subsystem
	FOnFindSessionsCompleteDelegate Delegate;//デリゲート宣言

	// Handle to the registered OnFindSessionsComplete delegate
	FDelegateHandle DelegateHandle;//デリゲートハンドル宣言

	// Object to track search results
	TSharedPtr<FOnlineSessionSearch> SearchObject;

	// Maximum number of results to return
	int MaxResults;

	// Optional: if searching within a matchmaking pool
	FString OculusPool;

	bool bSearchModeratedRoomsOnly;
};

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

#include "OculusFindSessionsCallbackProxy.h"
#include "OnlineSubsystemOculusPrivate.h"
#include "Online.h"
#include "OnlineSessionInterfaceOculus.h"
#include "OnlineSubsystemOculusPrivate.h"

UOculusFindSessionsCallbackProxy::UOculusFindSessionsCallbackProxy(const FObjectInitializer& ObjectInitializer)
	: Super(ObjectInitializer)
	  , Delegate(FOnFindSessionsCompleteDelegate::CreateUObject(this, &ThisClass::OnCompleted))
	  , MaxResults(0)
	  , bSearchModeratedRoomsOnly(false)
{
//デリゲートにOnComplitedをバインド
}

UOculusFindSessionsCallbackProxy* UOculusFindSessionsCallbackProxy::FindMatchmakingSessions(int32 MaxResults, FString OculusMatchmakingPool)
{
	UOculusFindSessionsCallbackProxy* Proxy = NewObject<UOculusFindSessionsCallbackProxy>();
	Proxy->SetFlags(RF_StrongRefOnFrame);
	Proxy->MaxResults = MaxResults;
	Proxy->OculusPool = MoveTemp(OculusMatchmakingPool);
	Proxy->bSearchModeratedRoomsOnly = false;
	return Proxy;
}

UOculusFindSessionsCallbackProxy* UOculusFindSessionsCallbackProxy::FindModeratedSessions(int32 MaxResults)
{
	UOculusFindSessionsCallbackProxy* Proxy = NewObject<UOculusFindSessionsCallbackProxy>();
	Proxy->SetFlags(RF_StrongRefOnFrame);
	Proxy->MaxResults = MaxResults;
	Proxy->bSearchModeratedRoomsOnly = true;
	return Proxy;
}

void UOculusFindSessionsCallbackProxy::Activate()
{
PRAGMA_DISABLE_DEPRECATION_WARNINGS
	auto OculusSessionInterface = Online::GetSessionInterface(OCULUS_SUBSYSTEM);
PRAGMA_ENABLE_DEPRECATION_WARNINGS

	if (OculusSessionInterface.IsValid())
	{
        //デリゲートハンドルにDelegateを渡してる。（コールしてる）
		DelegateHandle = OculusSessionInterface->AddOnFindSessionsCompleteDelegate_Handle(Delegate);

		SearchObject = MakeShareable(new FOnlineSessionSearch);
		SearchObject->MaxSearchResults = MaxResults;
		SearchObject->QuerySettings.Set(SEARCH_OCULUS_MODERATED_ROOMS_ONLY, bSearchModeratedRoomsOnly, EOnlineComparisonOp::Equals);

		if (!OculusPool.IsEmpty())
		{
			SearchObject->QuerySettings.Set(SETTING_OCULUS_POOL, OculusPool, EOnlineComparisonOp::Equals);
		}

		OculusSessionInterface->FindSessions(0, SearchObject.ToSharedRef());
	}
	else
	{
		UE_LOG_ONLINE_SESSION(Error, TEXT("Oculus platform service not available. Skipping FindSessions."));
		TArray<FBlueprintSessionResult> Results;
		OnFailure.Broadcast(Results);
	}
}

void UOculusFindSessionsCallbackProxy::OnCompleted(bool bSuccess)
{
PRAGMA_DISABLE_DEPRECATION_WARNINGS
	auto OculusSessionInterface = Online::GetSessionInterface(OCULUS_SUBSYSTEM);
PRAGMA_ENABLE_DEPRECATION_WARNINGS

	if (OculusSessionInterface.IsValid())
	{
		OculusSessionInterface->ClearOnFindSessionsCompleteDelegate_Handle(DelegateHandle);
	}

	TArray<FBlueprintSessionResult> Results;

	if (bSuccess && SearchObject.IsValid())
	{
		for (auto& Result : SearchObject->SearchResults)
		{
			FBlueprintSessionResult BPResult;
			BPResult.OnlineResult = Result;
			Results.Add(BPResult);
		}

		OnSuccess.Broadcast(Results);
	}
	else
	{
		OnFailure.Broadcast(Results);
	}
}