Files
UnrealEngine/Engine/Source/Runtime/SlateCore/Private/SlotBase.cpp
2025-05-18 13:04:45 +08:00

101 lines
2.1 KiB
C++

// Copyright Epic Games, Inc. All Rights Reserved.
#include "SlotBase.h"
#include "Layout/Children.h"
#include "Widgets/SWidget.h"
#include "Widgets/SNullWidget.h"
FSlotBase::FSlotBase()
: Owner(nullptr)
, Widget(SNullWidget::NullWidget)
{
}
FSlotBase::FSlotBase(const FChildren& Children)
: Owner(&Children)
, Widget(SNullWidget::NullWidget)
{
}
FSlotBase::FSlotBase( const TSharedRef<SWidget>& InWidget )
: Owner(nullptr)
, Widget(InWidget)
{
}
SWidget* FSlotBase::GetOwnerWidget() const
{
return GetOwner() ? &(GetOwner()->GetOwner()) : nullptr;
}
void FSlotBase::SetOwner(const FChildren& InChildren)
{
if (Owner != &InChildren)
{
if (ensureMsgf(Owner == nullptr, TEXT("Slots should not be reassigned to different parents.")))
{
Owner = &InChildren;
AfterContentOrOwnerAssigned();
}
}
}
const TSharedPtr<SWidget> FSlotBase::DetachWidget()
{
if (Widget != SNullWidget::NullWidget)
{
Widget->ConditionallyDetatchParentWidget(GetOwnerWidget());
// Invalidate Prepass?
const TSharedRef<SWidget> MyExWidget = Widget;
Widget = SNullWidget::NullWidget;
return MyExWidget;
}
else
{
// Nothing to detach!
return TSharedPtr<SWidget>();
}
}
void FSlotBase::Invalidate(EInvalidateWidgetReason InvalidateReason)
{
// If a slot invalidates it needs to invalidate the parent of widget of its content.
if (SWidget* OwnerWidget = GetOwnerWidget())
{
OwnerWidget->Invalidate(InvalidateReason);
}
}
void FSlotBase::DetatchParentFromContent()
{
if (Widget != SNullWidget::NullWidget)
{
Widget->ConditionallyDetatchParentWidget(GetOwnerWidget());
}
}
void FSlotBase::AfterContentOrOwnerAssigned()
{
if (SWidget* OwnerWidget = GetOwnerWidget())
{
if (Widget != SNullWidget::NullWidget)
{
// TODO NDarnell I want to enable this, but too many places in the codebase
// have made assumptions about being able to freely reparent widgets, while they're
// still connected to an existing hierarchy.
//ensure(!Widget->IsParentValid());
Widget->AssignParentWidget(OwnerWidget->AsShared());
}
}
}
FSlotBase::~FSlotBase()
{
DetatchParentFromContent();
}