int32 SWidget::Paint(const FPaintArgs& Args, const FGeometry& AllottedGeometry, const FSlateRect& MyClippingRect, FSlateWindowElementList& OutDrawElements, int32 LayerId, const FWidgetStyle& InWidgetStyle, bool bParentEnabled) const
{
INC_DWORD_STAT(STAT_SlateNumPaintedWidgets);
SLATE_CYCLE_COUNTER_SCOPE_CUSTOM_DETAILED(SLATE_STATS_DETAIL_LEVEL_MED, GSlateOnPaint, GetType());
// Save the current layout cache we're associated with (if any)
LayoutCache = Args.GetLayoutCache();
// Record if we're part of a volatility pass, this is critical for ensuring we don't report a child
// of a volatile widget as non-volatile, causing the invalidation panel to do work that's not required.
bInheritedVolatility = Args.IsVolatilityPass();
// If this paint pass is to cache off our geometry, but we're a volatile widget,
// record this widget as volatile in the draw elements so that we get our own tick/paint
// pass later when the layout cache draws.
if ( Args.IsCaching() && IsVolatile() )
{
const int32 VolatileLayerId = LayerId + 1;
OutDrawElements.QueueVolatilePainting(
FSlateWindowElementList::FVolatilePaint(SharedThis(this), Args, AllottedGeometry, MyClippingRect, VolatileLayerId, InWidgetStyle, bParentEnabled));
return VolatileLayerId;
}
if ( bFoldTick && bCanTick )
{
FGeometry TickGeometry = AllottedGeometry;
TickGeometry.AppendTransform( FSlateLayoutTransform(Args.GetWindowToDesktopTransform()) );
SWidget* MutableThis = const_cast<SWidget*>(this);
MutableThis->ExecuteActiveTimers( Args.GetCurrentTime(), Args.GetDeltaTime() );
MutableThis->Tick( TickGeometry, Args.GetCurrentTime(), Args.GetDeltaTime() );
}
// Record hit test geometry, but only if we're not caching.
const FPaintArgs UpdatedArgs = Args.RecordHittestGeometry(this, AllottedGeometry, MyClippingRect);
// Paint the geometry of this widget.
int32 NewLayerID = OnPaint(UpdatedArgs, AllottedGeometry, MyClippingRect, OutDrawElements, LayerId, InWidgetStyle, bParentEnabled);
// Check if we need to show the keyboard focus ring, this is only necessary if the widget could be focused.
if ( bCanSupportFocus && SupportsKeyboardFocus() )
{
bool bShowUserFocus = FSlateApplicationBase::Get().ShowUserFocus(SharedThis(this));
if (bShowUserFocus)
{
const FSlateBrush* BrushResource = GetFocusBrush();
if (BrushResource != nullptr)
{
FSlateDrawElement::MakeBox(
OutDrawElements,
NewLayerID,
AllottedGeometry.ToPaintGeometry(),
BrushResource,
MyClippingRect,
ESlateDrawEffect::None,
BrushResource->GetTint(InWidgetStyle)
);
}
}
}
return NewLayerID;
}
