int32 SInvalidationPanel::OnPaint( const FPaintArgs& Args, const FGeometry& AllottedGeometry, const FSlateRect& MyClippingRect, FSlateWindowElementList& OutDrawElements, int32 LayerId, const FWidgetStyle& InWidgetStyle, bool bParentEnabled ) const
{
if ( GetCanCache() )
{
const bool bWasCachingNeeded = bNeedsCaching;
if ( bNeedsCaching )
{
SInvalidationPanel* MutableThis = const_cast<SInvalidationPanel*>( this );
// Always set the caching flag to false first, during the paint / tick pass we may change something
// to volatile and need to re-cache.
bNeedsCaching = false;
bIsInvalidating = true;
if ( !CachedWindowElements.IsValid() || CachedWindowElements->GetWindow() != OutDrawElements.GetWindow() )
{
CachedWindowElements = MakeShareable(new FSlateWindowElementList(OutDrawElements.GetWindow()));
}
else
{
CachedWindowElements->Reset();
}
// Reset the cached node pool index so that we effectively reset the pool.
LastUsedCachedNodeIndex = 0;
RootCacheNode = CreateCacheNode();
RootCacheNode->Initialize(Args, SharedThis(MutableThis), AllottedGeometry, MyClippingRect);
//TODO: When SWidget::Paint is called don't drag self if volatile, and we're doing a cache pass.
CachedMaxChildLayer = SCompoundWidget::OnPaint(
Args.EnableCaching(SharedThis(MutableThis), RootCacheNode, true, false),
AllottedGeometry,
MyClippingRect,
*CachedWindowElements.Get(),
LayerId,
InWidgetStyle,
bParentEnabled);
if ( bCacheRelativeTransforms )
{
CachedAbsolutePosition = AllottedGeometry.Position;
}
LastLayerId = LayerId;
LastHitTestIndex = Args.GetLastHitTestIndex();
bIsInvalidating = false;
}
// The hit test grid is actually populated during the initial cache phase, so don't bother
// recording the hit test geometry on the same frame that we regenerate the cache.
if ( bWasCachingNeeded == false )
{
RootCacheNode->RecordHittestGeometry(Args.GetGrid(), Args.GetLastHitTestIndex());
}
if ( bCacheRelativeTransforms )
{
FVector2D DeltaPosition = AllottedGeometry.Position - CachedAbsolutePosition;
const TArray<FSlateDrawElement>& CachedElements = CachedWindowElements->GetDrawElements();
const int32 CachedElementCount = CachedElements.Num();
for ( int32 Index = 0; Index < CachedElementCount; Index++ )
{
const FSlateDrawElement& LocalElement = CachedElements[Index];
FSlateDrawElement AbsElement = LocalElement;
AbsElement.SetPosition(LocalElement.GetPosition() + DeltaPosition);
AbsElement.SetClippingRect(LocalElement.GetClippingRect().OffsetBy(DeltaPosition));
OutDrawElements.AddItem(AbsElement);
}
}
else
{
OutDrawElements.AppendDrawElements(CachedWindowElements->GetDrawElements());
}
int32 OutMaxChildLayer = CachedMaxChildLayer;
// Paint the volatile elements
if ( CachedWindowElements.IsValid() )
{
OutMaxChildLayer = FMath::Max(CachedMaxChildLayer, CachedWindowElements->PaintVolatile(OutDrawElements));
}
#if !UE_BUILD_SHIPPING
if ( IsInvalidationDebuggingEnabled() )
{
// Draw a green or red border depending on if we were invalidated this frame.
{
check(Args.IsCaching() == false);
//const bool bShowOutlineAsCached = Args.IsCaching() || bWasCachingNeeded == false;
const FLinearColor DebugTint = bWasCachingNeeded ? FLinearColor::Red : FLinearColor::Green;
FGeometry ScaledOutline = AllottedGeometry.MakeChild(FVector2D(0, 0), AllottedGeometry.GetLocalSize() * AllottedGeometry.Scale, Inverse(AllottedGeometry.Scale));
FSlateDrawElement::MakeBox(
OutDrawElements,
++OutMaxChildLayer,
ScaledOutline.ToPaintGeometry(),
FCoreStyle::Get().GetBrush(TEXT("Debug.Border")),
MyClippingRect,
ESlateDrawEffect::None,
DebugTint
);
}
// Draw a yellow outline around any volatile elements.
const TArray< TSharedRef<FSlateWindowElementList::FVolatilePaint> >& VolatileElements = CachedWindowElements->GetVolatileElements();
for ( const TSharedRef<FSlateWindowElementList::FVolatilePaint>& VolatileElement : VolatileElements )
{
FSlateDrawElement::MakeBox(
OutDrawElements,
++OutMaxChildLayer,
VolatileElement->GetGeometry().ToPaintGeometry(),
FCoreStyle::Get().GetBrush(TEXT("FocusRectangle")),
MyClippingRect,
ESlateDrawEffect::None,
FLinearColor::Yellow
);
}
// Draw a white flash for any widget that invalidated us this frame.
for ( TWeakPtr<SWidget> Invalidator : InvalidatorWidgets )
{
TSharedPtr<SWidget> SafeInvalidator = Invalidator.Pin();
if ( SafeInvalidator.IsValid() )
{
FWidgetPath WidgetPath;
if ( FSlateApplication::Get().GeneratePathToWidgetUnchecked(SafeInvalidator.ToSharedRef(), WidgetPath, EVisibility::All) )
{
FArrangedWidget ArrangedWidget = WidgetPath.FindArrangedWidget(SafeInvalidator.ToSharedRef()).Get(FArrangedWidget::NullWidget);
ArrangedWidget.Geometry.AppendTransform( FSlateLayoutTransform(Inverse(Args.GetWindowToDesktopTransform())) );
FSlateDrawElement::MakeBox(
OutDrawElements,
++OutMaxChildLayer,
ArrangedWidget.Geometry.ToPaintGeometry(),
FCoreStyle::Get().GetBrush(TEXT("WhiteBrush")),
MyClippingRect,
ESlateDrawEffect::None,
FLinearColor::White.CopyWithNewOpacity(0.6f)
);
}
}
}
InvalidatorWidgets.Reset();
}
#endif
return OutMaxChildLayer;
}
else
{
return SCompoundWidget::OnPaint(Args, AllottedGeometry, MyClippingRect, OutDrawElements, LayerId, InWidgetStyle, bParentEnabled);
}
}
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;
}