Cleaned unused delegates code:

- Removed code allowing to register game delegates outside of the delegates container.
- Removed unused multi-context delegate that is not part of the container.

Source/ImGui/Private/ImGuiContextManager.cpp

@@ -152,7 +152,7 @@ FImGuiContextManager::FContextData& FImGuiContextManager::GetEditorContextData()
 
 	if (UNLIKELY(!Data))
 	{
-		Data = &Contexts.Emplace(Utilities::EDITOR_CONTEXT_INDEX, FContextData{ GetEditorContextName(), Utilities::EDITOR_CONTEXT_INDEX, OnDrawMultiContext, FontAtlas, DPIScale, -1 });
+		Data = &Contexts.Emplace(Utilities::EDITOR_CONTEXT_INDEX, FContextData{ GetEditorContextName(), Utilities::EDITOR_CONTEXT_INDEX, FontAtlas, DPIScale, -1 });
 		OnContextProxyCreated.Broadcast(Utilities::EDITOR_CONTEXT_INDEX, *Data->ContextProxy);
 	}
 
@@ -167,7 +167,7 @@ FImGuiContextManager::FContextData& FImGuiContextManager::GetStandaloneWorldCont
 
 	if (UNLIKELY(!Data))
 	{
-		Data = &Contexts.Emplace(Utilities::STANDALONE_GAME_CONTEXT_INDEX, FContextData{ GetWorldContextName(), Utilities::STANDALONE_GAME_CONTEXT_INDEX, OnDrawMultiContext, FontAtlas, DPIScale });
+		Data = &Contexts.Emplace(Utilities::STANDALONE_GAME_CONTEXT_INDEX, FContextData{ GetWorldContextName(), Utilities::STANDALONE_GAME_CONTEXT_INDEX, FontAtlas, DPIScale });
 		OnContextProxyCreated.Broadcast(Utilities::STANDALONE_GAME_CONTEXT_INDEX, *Data->ContextProxy);
 	}
 
@@ -209,7 +209,7 @@ FImGuiContextManager::FContextData& FImGuiContextManager::GetWorldContextData(co
 #if WITH_EDITOR
 	if (UNLIKELY(!Data))
 	{
-		Data = &Contexts.Emplace(Index, FContextData{ GetWorldContextName(World), Index, OnDrawMultiContext, FontAtlas, DPIScale, WorldContext->PIEInstance });
+		Data = &Contexts.Emplace(Index, FContextData{ GetWorldContextName(World), Index, FontAtlas, DPIScale, WorldContext->PIEInstance });
 		OnContextProxyCreated.Broadcast(Index, *Data->ContextProxy);
 	}
 	else
@@ -220,7 +220,7 @@ FImGuiContextManager::FContextData& FImGuiContextManager::GetWorldContextData(co
 #else
 	if (UNLIKELY(!Data))
 	{
-		Data = &Contexts.Emplace(Index, FContextData{ GetWorldContextName(World), Index, OnDrawMultiContext, FontAtlas, DPIScale });
+		Data = &Contexts.Emplace(Index, FContextData{ GetWorldContextName(World), Index, FontAtlas, DPIScale });
 		OnContextProxyCreated.Broadcast(Index, *Data->ContextProxy);
 	}
 #endif

Source/ImGui/Private/ImGuiContextManager.h

@@ -58,10 +58,6 @@ public:
 		return Data ? Data->ContextProxy.Get() : nullptr;
 	}
 
-	// Delegate called for all contexts in manager, right after calling context specific draw event. Allows listeners
-	// draw the same content to multiple contexts.
-	FSimpleMulticastDelegate OnDrawMultiContext;
-
 	// Delegate called when a new context proxy is created.
 	FContextProxyCreatedDelegate OnContextProxyCreated;
 
@@ -74,9 +70,9 @@ private:
 
 	struct FContextData
 	{
-		FContextData(const FString& ContextName, int32 ContextIndex, FSimpleMulticastDelegate& SharedDrawEvent, ImFontAtlas& FontAtlas, float DPIScale, int32 InPIEInstance = -1)
+		FContextData(const FString& ContextName, int32 ContextIndex, ImFontAtlas& FontAtlas, float DPIScale, int32 InPIEInstance = -1)
 			: PIEInstance(InPIEInstance)
-			, ContextProxy(new FImGuiContextProxy(ContextName, ContextIndex, &SharedDrawEvent, &FontAtlas, DPIScale))
+			, ContextProxy(new FImGuiContextProxy(ContextName, ContextIndex, &FontAtlas, DPIScale))
 		{
 		}
 

Source/ImGui/Private/ImGuiContextProxy.cpp

@@ -73,10 +73,9 @@ namespace
 	};
 }
 
-FImGuiContextProxy::FImGuiContextProxy(const FString& InName, int32 InContextIndex, FSimpleMulticastDelegate* InSharedDrawEvent, ImFontAtlas* InFontAtlas, float InDPIScale)
+FImGuiContextProxy::FImGuiContextProxy(const FString& InName, int32 InContextIndex, ImFontAtlas* InFontAtlas, float InDPIScale)
 	: Name(InName)
 	, ContextIndex(InContextIndex)
-	, SharedDrawEvent(InSharedDrawEvent)
 	, IniFilename(TCHAR_TO_ANSI(*GetIniFile(InName)))
 {
 	// Create context.
@@ -295,11 +294,6 @@ void FImGuiContextProxy::BroadcastWorldDebug()
 
 void FImGuiContextProxy::BroadcastMultiContextDebug()
 {
-	if (SharedDrawEvent && SharedDrawEvent->IsBound())
-	{
-		SharedDrawEvent->Broadcast();
-	}
-
 	FSimpleMulticastDelegate& MultiContextDebugEvent = FImGuiDelegatesContainer::Get().OnMultiContextDebug();
 	if (MultiContextDebugEvent.IsBound())
 	{

Source/ImGui/Private/ImGuiContextProxy.h

@@ -19,7 +19,7 @@ class FImGuiContextProxy
 {
 public:
 
-	FImGuiContextProxy(const FString& Name, int32 InContextIndex, FSimpleMulticastDelegate* InSharedDrawEvent, ImFontAtlas* InFontAtlas, float InDPIScale);
+	FImGuiContextProxy(const FString& Name, int32 InContextIndex, ImFontAtlas* InFontAtlas, float InDPIScale);
 	~FImGuiContextProxy();
 
 	FImGuiContextProxy(const FImGuiContextProxy&) = delete;
@@ -68,7 +68,8 @@ public:
 	// Cursor type desired by this context (updated once per frame during context update).
 	EMouseCursor::Type GetMouseCursor() const { return MouseCursor;  }
 
-	// Delegate called right before ending the frame to allows listeners draw their controls.
+	// Internal draw event used to draw module's examples and debug widgets. Unlike the delegates container, it is not
+	// passed when the module is reloaded, so all objects that are unloaded with the module should register here.
 	FSimpleMulticastDelegate& OnDraw() { return DrawEvent; }
 
 	// Call early debug events to allow listeners draw their debug widgets.
@@ -116,7 +117,6 @@ private:
 	uint32 LastFrameNumber = 0;
 
 	FSimpleMulticastDelegate DrawEvent;
-	FSimpleMulticastDelegate* SharedDrawEvent = nullptr;
 
 	std::string IniFilename;
 };

Source/ImGui/Private/ImGuiModule.cpp

@@ -15,8 +15,6 @@
 
 #include <Interfaces/IPluginManager.h>
 
-#define IMGUI_REDIRECT_OBSOLETE_DELEGATES 1
-
 
 #define LOCTEXT_NAMESPACE "FImGuiModule"
 
@@ -44,62 +42,24 @@ static FImGuiEditor* ImGuiEditor = nullptr;
 #if WITH_EDITOR
 FImGuiDelegateHandle FImGuiModule::AddEditorImGuiDelegate(const FImGuiDelegate& Delegate)
 {
-#if IMGUI_REDIRECT_OBSOLETE_DELEGATES
 	return { FImGuiDelegatesContainer::Get().OnWorldDebug(Utilities::EDITOR_CONTEXT_INDEX).Add(Delegate),
 		EDelegateCategory::Default, Utilities::EDITOR_CONTEXT_INDEX };
-#else
-	checkf(ImGuiModuleManager, TEXT("Null pointer to internal module implementation. Is module available?"));
-
-	return { ImGuiModuleManager->GetContextManager().GetEditorContextProxy().OnDraw().Add(Delegate),
-		EDelegateCategory::Default, Utilities::EDITOR_CONTEXT_INDEX };
-#endif // IMGUI_REDIRECT_OBSOLETE_DELEGATES
 }
 #endif
 
 FImGuiDelegateHandle FImGuiModule::AddWorldImGuiDelegate(const FImGuiDelegate& Delegate)
 {
-#if IMGUI_REDIRECT_OBSOLETE_DELEGATES
 	const int32 ContextIndex = Utilities::GetWorldContextIndex((UWorld*)GWorld);
 	return { FImGuiDelegatesContainer::Get().OnWorldDebug(ContextIndex).Add(Delegate), EDelegateCategory::Default, ContextIndex };
-#else
-	checkf(ImGuiModuleManager, TEXT("Null pointer to internal module implementation. Is module available?"));
-
-#if WITH_EDITOR
-	checkf(GEngine, TEXT("Null GEngine. AddWorldImGuiDelegate should be only called with GEngine initialized."));
-
-	const FWorldContext* WorldContext = Utilities::GetWorldContext(GEngine->GameViewport);
-	if (!WorldContext)
-	{
-		WorldContext = Utilities::GetWorldContextFromNetMode(ENetMode::NM_DedicatedServer);
-	}
-
-	checkf(WorldContext, TEXT("Couldn't find current world. AddWorldImGuiDelegate should be only called from a valid world."));
-
-	int32 Index;
-	FImGuiContextProxy& Proxy = ImGuiModuleManager->GetContextManager().GetWorldContextProxy(*WorldContext->World(), Index);
-#else
-	const int32 Index = Utilities::STANDALONE_GAME_CONTEXT_INDEX;
-	FImGuiContextProxy& Proxy = ImGuiModuleManager->GetContextManager().GetWorldContextProxy();
-#endif
-
-	return{ Proxy.OnDraw().Add(Delegate), EDelegateCategory::Default, Index };
-#endif // IMGUI_REDIRECT_OBSOLETE_DELEGATES
 }
 
 FImGuiDelegateHandle FImGuiModule::AddMultiContextImGuiDelegate(const FImGuiDelegate& Delegate)
 {
-#if IMGUI_REDIRECT_OBSOLETE_DELEGATES
 	return { FImGuiDelegatesContainer::Get().OnMultiContextDebug().Add(Delegate), EDelegateCategory::MultiContext };
-#else
-	checkf(ImGuiModuleManager, TEXT("Null pointer to internal module implementation. Is module available?"));
-
-	return { ImGuiModuleManager->GetContextManager().OnDrawMultiContext.Add(Delegate), EDelegateCategory::MultiContext };
-#endif
 }
 
 void FImGuiModule::RemoveImGuiDelegate(const FImGuiDelegateHandle& Handle)
 {
-#if IMGUI_REDIRECT_OBSOLETE_DELEGATES
 	if (Handle.Category == EDelegateCategory::MultiContext)
 	{
 		FImGuiDelegatesContainer::Get().OnMultiContextDebug().Remove(Handle.Handle);
@@ -108,19 +68,6 @@ void FImGuiModule::RemoveImGuiDelegate(const FImGuiDelegateHandle& Handle)
 	{
 		FImGuiDelegatesContainer::Get().OnWorldDebug(Handle.Index).Remove(Handle.Handle);
 	}
-#else
-	if (ImGuiModuleManager)
-	{
-		if (Handle.Category == EDelegateCategory::MultiContext)
-		{
-			ImGuiModuleManager->GetContextManager().OnDrawMultiContext.Remove(Handle.Handle);
-		}
-		else if (auto* Proxy = ImGuiModuleManager->GetContextManager().GetContextProxy(Handle.Index))
-		{
-			Proxy->OnDraw().Remove(Handle.Handle);
-		}
-	}
-#endif
 }
 
 #endif // IMGUI_WITH_OBSOLETE_DELEGATES