C++ TAttribute::IsSet方法代码示例

void SWidget::Construct(
	const TAttribute<FText> & InToolTipText ,
	const TSharedPtr<IToolTip> & InToolTip ,
	const TAttribute< TOptional<EMouseCursor::Type> > & InCursor ,
	const TAttribute<bool> & InEnabledState ,
	const TAttribute<EVisibility> & InVisibility,
	const TAttribute<TOptional<FSlateRenderTransform>>& InTransform,
	const TAttribute<FVector2D>& InTransformPivot,
	const FName& InTag,
	const bool InForceVolatile,
	const TArray<TSharedRef<ISlateMetaData>>& InMetaData
)
{
	if ( InToolTip.IsValid() )
	{
		// If someone specified a fancy widget tooltip, use it.
		ToolTip = InToolTip;
	}
	else if ( InToolTipText.IsSet() )
	{
		// If someone specified a text binding, make a tooltip out of it
		ToolTip = FSlateApplicationBase::Get().MakeToolTip(InToolTipText);
	}
	else if( !ToolTip.IsValid() || (ToolTip.IsValid() && ToolTip->IsEmpty()) )
	{	
		// We don't have a tooltip.
		ToolTip.Reset();
	}

	Cursor = InCursor;
	EnabledState = InEnabledState;
	Visibility = InVisibility;
	RenderTransform = InTransform;
	RenderTransformPivot = InTransformPivot;
	Tag = InTag;
	bForceVolatile = InForceVolatile;
	MetaData = InMetaData;
}

void FFoliageTypePaintingCustomization::ShowFoliagePropertiesForCategory(IDetailLayoutBuilder& DetailLayoutBuilder, const FName CategoryName, TMap<const FName, IDetailPropertyRow*>& OutDetailRowsByPropertyName)
{
    // Properties that have a ReapplyCondition should be disabled behind the specified property when in reapply mode
    static const FName ReapplyConditionKey("ReapplyCondition");

    // Properties with a HideBehind property specified should only be shown if that property is true, non-zero, or not empty
    static const FName HideBehindKey("HideBehind");

    IDetailCategoryBuilder& CategoryBuilder = DetailLayoutBuilder.EditCategory(CategoryName);
    TArray<TSharedRef<IPropertyHandle>> CategoryProperties;
    CategoryBuilder.GetDefaultProperties(CategoryProperties, true, true);

    // Determine whether each property should be shown and how
    for (auto& PropertyHandle : CategoryProperties)
    {
        bool bShowingProperty = false;
        if (UProperty* Property = PropertyHandle->GetProperty())
        {
            // Check to see if this property can be reapplied
            TSharedPtr<IPropertyHandle> ReapplyConditionPropertyHandle = DetailLayoutBuilder.GetProperty(*Property->GetMetaData(ReapplyConditionKey));
            if (ReapplyConditionPropertyHandle.IsValid() && ReapplyConditionPropertyHandle->IsValidHandle())
            {
                // Create a custom entry that allows explicit enabling/disabling of the property when reapplying
                TSharedPtr<IPropertyHandle> PropertyHandlePtr = PropertyHandle;
                OutDetailRowsByPropertyName.FindOrAdd(PropertyHandle->GetProperty()->GetFName()) =
                    &AddFoliageProperty(CategoryBuilder, PropertyHandlePtr, ReapplyConditionPropertyHandle, TAttribute<EVisibility>(), TAttribute<bool>());
            }
            else
            {
                TSharedPtr<IPropertyHandle> InvalidProperty;
                TSharedPtr<IPropertyHandle> PropertyHandlePtr = PropertyHandle;

                // Check to see if this property is hidden behind another
                TSharedPtr<IPropertyHandle> HiddenBehindPropertyHandle = DetailLayoutBuilder.GetProperty(*Property->GetMetaData(HideBehindKey));
                if (HiddenBehindPropertyHandle.IsValid() && HiddenBehindPropertyHandle->IsValidHandle())
                {
                    TAttribute<bool> IsEnabledAttribute;
                    ReapplyConditionPropertyHandle = DetailLayoutBuilder.GetProperty(*HiddenBehindPropertyHandle->GetProperty()->GetMetaData(ReapplyConditionKey));
                    if (ReapplyConditionPropertyHandle.IsValid() && ReapplyConditionPropertyHandle->IsValidHandle())
                    {
                        // If the property this is hidden behind has a reapply condition, disable this when the condition is false
                        IsEnabledAttribute = TAttribute<bool>::Create(TAttribute<bool>::FGetter::CreateSP(this, &FFoliageTypePaintingCustomization::IsReapplyPropertyEnabled, ReapplyConditionPropertyHandle));
                    }

                    TAttribute<EVisibility> VisibilityAttribute;
                    GetHiddenPropertyVisibility(HiddenBehindPropertyHandle, !IsEnabledAttribute.IsSet(), VisibilityAttribute);

                    OutDetailRowsByPropertyName.FindOrAdd(PropertyHandle->GetProperty()->GetFName()) =
                        &AddFoliageProperty(CategoryBuilder, PropertyHandlePtr, InvalidProperty, VisibilityAttribute, IsEnabledAttribute);
                }
                else
                {
                    // This property cannot be reapplied and isn't hidden behind anything, so show it whenever the reapply tool isn't active
                    OutDetailRowsByPropertyName.FindOrAdd(PropertyHandle->GetProperty()->GetFName()) =
                        &AddFoliageProperty(CategoryBuilder, PropertyHandlePtr, InvalidProperty,
                                            TAttribute<EVisibility>::Create(TAttribute<EVisibility>::FGetter::CreateSP(this, &FFoliageTypePaintingCustomization::GetNonReapplyPropertyVisibility)),
                                            TAttribute<bool>());
                }
            }
        }
    }
}