int ScrollbarThemeOverlay::thumbPosition(const ScrollbarThemeClient& scrollbar)
{
if (!scrollbar.totalSize())
return 0;
int trackLen = trackLength(scrollbar);
float proportion = static_cast<float>(scrollbar.currentPos()) / scrollbar.totalSize();
return round(proportion * trackLen);
}
void ScrollbarThemeAura::paintButton(GraphicsContext& gc, const ScrollbarThemeClient& scrollbar, const IntRect& rect, ScrollbarPart part)
{
DisplayItem::Type displayItemType = buttonPartToDisplayItemType(part);
if (DrawingRecorder::useCachedDrawingIfPossible(gc, scrollbar, displayItemType))
return;
PartPaintingParams params = buttonPartPaintingParams(scrollbar, scrollbar.currentPos(), part);
if (!params.shouldPaint)
return;
DrawingRecorder recorder(gc, scrollbar, displayItemType, rect);
Platform::current()->themeEngine()->paint(gc.canvas(), params.part, params.state, WebRect(rect), 0);
}
