UHorizontalBoxSlot C++ bugged?

Development Programming & Scripting C++
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1

Hi! When creating a UHorizontalBox in c++ and adding another widget to it, e.g. UOverlay widget, then you CANNOT set the VerticalAlignment or HorizontalAlignment on the resulting UHorizontalBoxSlot object… :frowning:

Below is a snippet of my code:

// Create HorizontalBox
WidgetTree->RootWidget = WidgetTree->ConstructWidget<UHorizontalBox>();
UHorizontalBox* HBox= (UHorizontalBox*)WidgetTree->RootWidget;

// Create Overlay
UOverlay* Overlay = WidgetTree->ConstructWidget<UOverlay>();

// Add Overlay to the HBox and set alignments
UHorizontalBoxSlot* HBoxSlot = HBox->AddChildToHorizontalBox(Overlay);

// These next two lines never work... There's a BUG in the implementation.
HBoxSlot->SetHorizontalAlignment(EHorizontalAlignment::HAlign_Fill);
HBoxSlot->SetVerticalAlignment(EVerticalAlignment::VAlign_Fill);

Here is source code from the Engine UMG module:

//Engine\Source\Runtime\UMG\Private\Components\HorizontalBoxSlot.cpp
void UHorizontalBoxSlot::SetHorizontalAlignment(EHorizontalAlignment InHorizontalAlignment)
{
	HorizontalAlignment = InHorizontalAlignment;
	if ( Slot ) // THIS CONDITION IS NEVER TRUE? 
	{
		Slot->SetHorizontalAlignment(InHorizontalAlignment); 
	}
}

Slot is never true in this case. It is always a Nullptr, and therefore calling SetHorizontalAlignment() or SetVerticalAlignment() doesn’t work in c++.

Is it a bug or am I simply misusing these functions?