C++ PaintLayer::setContainsDirtyOverlayScrollbars方法代码示例

void ScrollableAreaPainter::paintOverflowControls(
    GraphicsContext& context,
    const IntPoint& paintOffset,
    const CullRect& cullRect,
    bool paintingOverlayControls) {
  // Don't do anything if we have no overflow.
  if (!getScrollableArea().box().hasOverflowClip())
    return;

  IntPoint adjustedPaintOffset = paintOffset;
  if (paintingOverlayControls)
    adjustedPaintOffset = getScrollableArea().cachedOverlayScrollbarOffset();

  CullRect adjustedCullRect(cullRect, -adjustedPaintOffset);

  // Overlay scrollbars paint in a second pass through the layer tree so that
  // they will paint on top of everything else. If this is the normal painting
  // pass, paintingOverlayControls will be false, and we should just tell the
  // root layer that there are overlay scrollbars that need to be painted. That
  // will cause the second pass through the layer tree to run, and we'll paint
  // the scrollbars then. In the meantime, cache tx and ty so that the second
  // pass doesn't need to re-enter the LayoutTree to get it right.
  if (getScrollableArea().hasOverlayScrollbars() && !paintingOverlayControls) {
    getScrollableArea().setCachedOverlayScrollbarOffset(paintOffset);
    // It's not necessary to do the second pass if the scrollbars paint into
    // layers.
    if ((getScrollableArea().horizontalScrollbar() &&
         getScrollableArea().layerForHorizontalScrollbar()) ||
        (getScrollableArea().verticalScrollbar() &&
         getScrollableArea().layerForVerticalScrollbar()))
      return;
    if (!overflowControlsIntersectRect(adjustedCullRect))
      return;

    LayoutView* layoutView = getScrollableArea().box().view();

    PaintLayer* paintingRoot =
        getScrollableArea().layer()->enclosingLayerWithCompositedLayerMapping(
            IncludeSelf);
    if (!paintingRoot)
      paintingRoot = layoutView->layer();

    paintingRoot->setContainsDirtyOverlayScrollbars(true);
    return;
  }

  // This check is required to avoid painting custom CSS scrollbars twice.
  if (paintingOverlayControls && !getScrollableArea().hasOverlayScrollbars())
    return;

  {
    Optional<ScopedPaintChunkProperties> scopedTransformProperty;
    if (RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
      const auto* objectProperties =
          getScrollableArea().box().paintProperties();
      if (objectProperties && objectProperties->scrollbarPaintOffset()) {
        PaintChunkProperties properties(
            context.getPaintController().currentPaintChunkProperties());
        properties.transform = objectProperties->scrollbarPaintOffset();
        scopedTransformProperty.emplace(
            context.getPaintController(), getScrollableArea().box(),
            DisplayItem::kScrollOverflowControls, properties);
      }
    }
    if (getScrollableArea().horizontalScrollbar() &&
        !getScrollableArea().layerForHorizontalScrollbar()) {
      TransformRecorder translateRecorder(
          context, *getScrollableArea().horizontalScrollbar(),
          AffineTransform::translation(adjustedPaintOffset.x(),
                                       adjustedPaintOffset.y()));
      getScrollableArea().horizontalScrollbar()->paint(context,
                                                       adjustedCullRect);
    }
    if (getScrollableArea().verticalScrollbar() &&
        !getScrollableArea().layerForVerticalScrollbar()) {
      TransformRecorder translateRecorder(
          context, *getScrollableArea().verticalScrollbar(),
          AffineTransform::translation(adjustedPaintOffset.x(),
                                       adjustedPaintOffset.y()));
      getScrollableArea().verticalScrollbar()->paint(context, adjustedCullRect);
    }
  }

  if (getScrollableArea().layerForScrollCorner())
    return;

  // We fill our scroll corner with white if we have a scrollbar that doesn't
  // run all the way up to the edge of the box.
  paintScrollCorner(context, adjustedPaintOffset, cullRect);

  // Paint our resizer last, since it sits on top of the scroll corner.
  paintResizer(context, adjustedPaintOffset, cullRect);
}

void ScrollableAreaPainter::paintOverflowControls(GraphicsContext* context, const IntPoint& paintOffset, const IntRect& damageRect, bool paintingOverlayControls)
{
    // Don't do anything if we have no overflow.
    if (!scrollableArea().box().hasOverflowClip())
        return;

    IntPoint adjustedPaintOffset = paintOffset;
    if (paintingOverlayControls)
        adjustedPaintOffset = scrollableArea().cachedOverlayScrollbarOffset();

    IntRect localDamageRect = damageRect;
    localDamageRect.moveBy(-adjustedPaintOffset);

    // Overlay scrollbars paint in a second pass through the layer tree so that they will paint
    // on top of everything else. If this is the normal painting pass, paintingOverlayControls
    // will be false, and we should just tell the root layer that there are overlay scrollbars
    // that need to be painted. That will cause the second pass through the layer tree to run,
    // and we'll paint the scrollbars then. In the meantime, cache tx and ty so that the
    // second pass doesn't need to re-enter the LayoutTree to get it right.
    if (scrollableArea().hasOverlayScrollbars() && !paintingOverlayControls) {
        scrollableArea().setCachedOverlayScrollbarOffset(paintOffset);
        // It's not necessary to do the second pass if the scrollbars paint into layers.
        if ((scrollableArea().horizontalScrollbar() && scrollableArea().layerForHorizontalScrollbar()) || (scrollableArea().verticalScrollbar() && scrollableArea().layerForVerticalScrollbar()))
            return;
        if (!overflowControlsIntersectRect(localDamageRect))
            return;

        LayoutView* layoutView = scrollableArea().box().view();

        PaintLayer* paintingRoot = scrollableArea().layer()->enclosingLayerWithCompositedLayerMapping(IncludeSelf);
        if (!paintingRoot)
            paintingRoot = layoutView->layer();

        paintingRoot->setContainsDirtyOverlayScrollbars(true);
        return;
    }

    // This check is required to avoid painting custom CSS scrollbars twice.
    if (paintingOverlayControls && !scrollableArea().hasOverlayScrollbars())
        return;

    {
        if (scrollableArea().horizontalScrollbar() && !scrollableArea().layerForHorizontalScrollbar()) {
            TransformRecorder translateRecorder(*context, *scrollableArea().horizontalScrollbar(), AffineTransform::translation(adjustedPaintOffset.x(), adjustedPaintOffset.y()));
            scrollableArea().horizontalScrollbar()->paint(context, localDamageRect);
        }
        if (scrollableArea().verticalScrollbar() && !scrollableArea().layerForVerticalScrollbar()) {
            TransformRecorder translateRecorder(*context, *scrollableArea().verticalScrollbar(), AffineTransform::translation(adjustedPaintOffset.x(), adjustedPaintOffset.y()));
            scrollableArea().verticalScrollbar()->paint(context, localDamageRect);
        }
    }

    if (scrollableArea().layerForScrollCorner())
        return;

    // We fill our scroll corner with white if we have a scrollbar that doesn't run all the way up to the
    // edge of the box.
    paintScrollCorner(context, adjustedPaintOffset, damageRect);

    // Paint our resizer last, since it sits on top of the scroll corner.
    paintResizer(context, adjustedPaintOffset, damageRect);
}