BindJoinableSpaces - Unreal

- Declaration

static FCavrnusBinding BindJoinableSpaces(FCavrnusSpaceInfoEvent SpaceAdded, FCavrnusSpaceInfoEvent SpaceUpdated, FCavrnusSpaceInfoEvent SpaceRemoved);

- Description

Triggers when spaces become available to you that you can join, or when their metadata changes.

When called, you will immediately get SpaceAdded events for all spaces currently in your list.

- Blueprint Sample

- Code Sample

SpaceListWidget.h:

#pragma once

#include "CoreMinimal.h"
#include "Types/CavrnusCallbackTypes.h"
#include "Blueprint/UserWidget.h"
#incldue "SpaceWidget.h"
#include "SpaceListWidget.generated.h"

UCLASS()
class MODULE_API USpaceListWidget: public UUserWidget
{
  GENERATED_BODY()

public:
  void NativeConstruct();

private:
  void OnSpaceAdded(FCavrnusSpaceInfo& SpaceInfo);
  void OnSpaceUpdated(FCavrnusSpaceInfo& SpaceInfo);
  void OnSpaceRemoved(FCavrnusSpaceInfo& SpaceInfo);
  
  FCavrnusBinding JoinableSpacesBinding;
  
  FCavrnusSpaceInfoEvent SpaceAdded;
  FCavrnusSpaceInfoEvent SpaceUpdated;
  FCavrnusSpaceInfoEvent SpaceRemoved;
  
  // USpaceWidget - theoretical list item or button that displays one joinable space
  TMap<FString, USpaceWidget*> SpaceWidgets;
};

SpaceListWidget.cpp

#include "SpaceListWidget.h"
#include "CavrnusFunctionLibrary.h"

USpaceListWidget::NativeConstruct()
{
  Super::NativeConstruct();
  
  SpaceAdded.BindUFunction(this, GET_FUNCTION_NAME_CHECKED(USpaceListWidget, OnSpaceAdded));
  SpaceUpdated.BindUFunction(this, GET_FUNCTION_NAME_CHECKED(USpaceListWidget, OnSpaceUpdated));
  SpaceRemoved.BindUFunction(this, GET_FUNCTION_NAME_CHECKED(USpaceListWidget, OnSpaceRemoved));
  
  JoinableSpacesBinding = UCavrnusFunctionLibrary::BindJoinableSpaces(OnSpaceAdded, OnSpaceUpdated, OnSpaceRemoved);
}

void USpaceListWidget::OnSpaceAdded(FCavrnusSpaceInfo& SpaceInfo)
{
  if (!SpaceWidgets.Contains(SpaceInfo.SpaceId))
  {
    // Received a new space ID. Create a new widget and add it to the list.
    USpaceWidget* NewWidget = CreateWidget<USpaceWidget>();
    NewWidget->Initialize(SpaceInfo);
    SpaceWidgets.Add(SpaceInfo.SpaceId, NewWidget);
  }
}

void USpaceListWidget::OnSpaceUpdated(FCavrnusSpaceInfo& SpaceInfo)
{
  if (SpaceWidgets.Contains(SpaceInfo.SpaceId))
  {
    // Update this listing.
    SpaceWidgets[SpaceInfo.SpaceId]->UpdateSpaceInfo(SpaceInfo);
  }
}

void USpaceListWidget::OnSpaceRemoved(FCavrnusSpaceInfo& SpaceInfo)
{
  if (SpaceWidgets.Contains(SpaceInfo.SpaceId))
  {
    // This widget is no longer necessary.
    SpaceWidgets[SpaceInfo.SpaceId]->BeginDestroy();
    SpaceWidgets.Remove(SpaceInfo.SpaceId);
  }
}