C++ LayoutRect类代码示例

static void mapCaretRectToCaretPainter(LayoutItem caretLayoutItem,
                                       LayoutBlockItem caretPainterItem,
                                       LayoutRect& caretRect) {
    // FIXME: This shouldn't be called on un-rooted subtrees.
    // FIXME: This should probably just use mapLocalToAncestor.
    // Compute an offset between the caretLayoutItem and the caretPainterItem.

    DCHECK(caretLayoutItem.isDescendantOf(caretPainterItem));

    bool unrooted = false;
    while (caretLayoutItem != caretPainterItem) {
        LayoutItem containerItem = caretLayoutItem.container();
        if (containerItem.isNull()) {
            unrooted = true;
            break;
        }
        caretRect.move(caretLayoutItem.offsetFromContainer(containerItem));
        caretLayoutItem = containerItem;
    }

    if (unrooted)
        caretRect = LayoutRect();
}

void RenderMultiColumnSet::repaintFlowThreadContent(const LayoutRect& repaintRect, bool immediate) const
{
    // Figure out the start and end columns and only check within that range so that we don't walk the
    // entire column set. Put the repaint rect into flow thread coordinates by flipping it first.
    LayoutRect flowThreadRepaintRect(repaintRect);
    flowThread()->flipForWritingMode(flowThreadRepaintRect);
    
    // Now we can compare this rect with the flow thread portions owned by each column. First let's
    // just see if the repaint rect intersects our flow thread portion at all.
    LayoutRect clippedRect(flowThreadRepaintRect);
    clippedRect.intersect(RenderRegion::flowThreadPortionOverflowRect());
    if (clippedRect.isEmpty())
        return;
    
    // Now we know we intersect at least one column. Let's figure out the logical top and logical
    // bottom of the area we're repainting.
    LayoutUnit repaintLogicalTop = isHorizontalWritingMode() ? flowThreadRepaintRect.y() : flowThreadRepaintRect.x();
    LayoutUnit repaintLogicalBottom = (isHorizontalWritingMode() ? flowThreadRepaintRect.maxY() : flowThreadRepaintRect.maxX()) - 1;
    
    unsigned startColumn = columnIndexAtOffset(repaintLogicalTop);
    unsigned endColumn = columnIndexAtOffset(repaintLogicalBottom);
    
    LayoutUnit colGap = columnGap();
    unsigned colCount = columnCount();
    for (unsigned i = startColumn; i <= endColumn; i++) {
        LayoutRect colRect = columnRectAt(i);
        
        // Get the portion of the flow thread that corresponds to this column.
        LayoutRect flowThreadPortion = flowThreadPortionRectAt(i);
        
        // Now get the overflow rect that corresponds to the column.
        LayoutRect flowThreadOverflowPortion = flowThreadPortionOverflowRect(flowThreadPortion, i, colCount, colGap);

        // Do a repaint for this specific column.
        repaintFlowThreadContentRectangle(repaintRect, immediate, flowThreadPortion, flowThreadOverflowPortion, colRect.location());
    }
}

void RenderTextControlSingleLine::paint(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
{
    RenderTextControl::paint(paintInfo, paintOffset);

    if (paintInfo.phase == PaintPhaseBlockBackground && m_shouldDrawCapsLockIndicator) {
        LayoutRect contentsRect = contentBoxRect();

        // Center in the block progression direction.
        if (isHorizontalWritingMode())
            contentsRect.setY((height() - contentsRect.height()) / 2);
        else
            contentsRect.setX((width() - contentsRect.width()) / 2);

        // Convert the rect into the coords used for painting the content
        contentsRect.moveBy(paintOffset + location());
        theme().paintCapsLockIndicator(*this, paintInfo, snappedIntRect(contentsRect));
    }
}

LayoutRect RootFrameViewport::scrollIntoView(const LayoutRect& rectInContent, const ScrollAlignment& alignX, const ScrollAlignment& alignY)
{
    // We want to move the rect into the viewport that excludes the scrollbars so we intersect
    // the visual viewport with the scrollbar-excluded frameView content rect. However, we don't
    // use visibleContentRect directly since it floors the scroll position. Instead, we use
    // FrameView::scrollPositionDouble and construct a LayoutRect from that (the FrameView size
    // is always integer sized.

    LayoutRect frameRectInContent = LayoutRect(
        layoutViewport().scrollPositionDouble(),
        layoutViewport().visibleContentRect().size());
    LayoutRect visualRectInContent = LayoutRect(
        layoutViewport().scrollPositionDouble() + toDoubleSize(visualViewport().scrollPositionDouble()),
        visualViewport().visibleContentRect().size());

    LayoutRect viewRectInContent = intersection(visualRectInContent, frameRectInContent);
    LayoutRect targetViewport =
        ScrollAlignment::getRectToExpose(viewRectInContent, rectInContent, alignX, alignY);

    // visualViewport.scrollIntoView will attempt to center the given rect within the viewport
    // so to prevent it from adjusting r's coordinates the rect must match the viewport's size
    // i.e. add the subtracted scrollbars from above back in.
    // FIXME: This is hacky and required because getRectToExpose doesn't naturally account
    // for the two viewports. crbug.com/449340.
    targetViewport.setSize(LayoutSize(visualViewport().visibleContentRect().size()));

    // Snap the visible rect to layout units to match the calculated target viewport rect.
    FloatRect visible =
        LayoutRect(visualViewport().scrollPositionDouble(), visualViewport().visibleContentRect().size());

    float centeringOffsetX = (visible.width() - targetViewport.width()) / 2;
    float centeringOffsetY = (visible.height() - targetViewport.height()) / 2;

    DoublePoint targetOffset(
        targetViewport.x() - centeringOffsetX,
        targetViewport.y() - centeringOffsetY);

    setScrollPosition(targetOffset, ProgrammaticScroll);

    // RootFrameViewport only changes the viewport relative to the document so we can't change the input
    // rect's location relative to the document origin.
    return rectInContent;
}

static void adjustBubblePosition(const LayoutRect& hostRect, HTMLElement* bubble)
{
    ASSERT(bubble);
    if (hostRect.isEmpty())
        return;
    double hostX = hostRect.x();
    double hostY = hostRect.y();
    if (RenderBox* container = bubble->renderer()->containingBlock()) {
        FloatPoint containerLocation = container->localToAbsolute();
        hostX -= containerLocation.x() + container->borderLeft();
        hostY -= containerLocation.y() + container->borderTop();
    }
    bubble->getInlineStyleDecl()->setProperty(CSSPropertyTop, hostY + hostRect.height(), CSSPrimitiveValue::CSS_PX);
    // The 'left' value of ::-webkit-validation-bubble-arrow.
    const int bubbleArrowTopOffset = 32;
    double bubbleX = hostX;
    if (hostRect.width() / 2 < bubbleArrowTopOffset)
        bubbleX = max(hostX + hostRect.width() / 2 - bubbleArrowTopOffset, 0.0);
    bubble->getInlineStyleDecl()->setProperty(CSSPropertyLeft, bubbleX, CSSPrimitiveValue::CSS_PX);
}

void RenderVideo::paintReplaced(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
{
    MediaPlayer* mediaPlayer = videoElement().player();
    bool displayingPoster = videoElement().shouldDisplayPosterImage();

    Page* page = frame().page();

    if (!displayingPoster && !mediaPlayer) {
        if (page && paintInfo.phase == PaintPhaseForeground)
            page->addRelevantUnpaintedObject(this, visualOverflowRect());
        return;
    }

    LayoutRect rect = videoBox();
    if (rect.isEmpty()) {
        if (page && paintInfo.phase == PaintPhaseForeground)
            page->addRelevantUnpaintedObject(this, visualOverflowRect());
        return;
    }
    rect.moveBy(paintOffset);

    if (page && paintInfo.phase == PaintPhaseForeground)
        page->addRelevantRepaintedObject(this, rect);

    LayoutRect contentRect = contentBoxRect();
    contentRect.moveBy(paintOffset);
    GraphicsContext& context = paintInfo.context();
    bool clip = !contentRect.contains(rect);
    GraphicsContextStateSaver stateSaver(context, clip);
    if (clip)
        context.clip(contentRect);

    if (displayingPoster)
        paintIntoRect(context, rect);
    else if (!videoElement().isFullscreen() || !mediaPlayer->supportsAcceleratedRendering()) {
        if (view().frameView().paintBehavior() & PaintBehaviorFlattenCompositingLayers)
            mediaPlayer->paintCurrentFrameInContext(context, rect);
        else
            mediaPlayer->paint(context, rect);
    }
}

void BlockFlowPainter::paintSelection(const PaintInfo& paintInfo, const LayoutPoint& paintOffset)
{
    ASSERT(paintInfo.phase == PaintPhaseForeground);
    if (!m_layoutBlockFlow.shouldPaintSelectionGaps())
        return;

    LayoutUnit lastTop = 0;
    LayoutUnit lastLeft = m_layoutBlockFlow.logicalLeftSelectionOffset(&m_layoutBlockFlow, lastTop);
    LayoutUnit lastRight = m_layoutBlockFlow.logicalRightSelectionOffset(&m_layoutBlockFlow, lastTop);

    LayoutRect bounds = m_layoutBlockFlow.visualOverflowRect();
    bounds.moveBy(paintOffset);

    // Only create a DrawingRecorder and ClipScope if skipRecording is false. This logic is needed
    // because selectionGaps(...) needs to be called even when we do not record.
    bool skipRecording = LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(paintInfo.context, m_layoutBlockFlow, DisplayItem::SelectionGap, paintOffset);
    Optional<LayoutObjectDrawingRecorder> drawingRecorder;
    Optional<ClipScope> clipScope;
    if (!skipRecording) {
        drawingRecorder.emplace(paintInfo.context, m_layoutBlockFlow, DisplayItem::SelectionGap, FloatRect(bounds), paintOffset);
        clipScope.emplace(paintInfo.context);
    }

    LayoutRect gapRectsBounds = m_layoutBlockFlow.selectionGaps(&m_layoutBlockFlow, paintOffset, LayoutSize(), lastTop, lastLeft, lastRight,
        skipRecording ? nullptr : &paintInfo,
        skipRecording ? nullptr : &(*clipScope));
    // TODO(wkorman): Rework below to process paint invalidation rects during layout rather than paint.
    if (!gapRectsBounds.isEmpty()) {
        PaintLayer* layer = m_layoutBlockFlow.enclosingLayer();
        gapRectsBounds.moveBy(-paintOffset);
        if (!m_layoutBlockFlow.hasLayer()) {
            LayoutRect localBounds(gapRectsBounds);
            m_layoutBlockFlow.flipForWritingMode(localBounds);
            gapRectsBounds = LayoutRect(m_layoutBlockFlow.localToAncestorQuad(FloatRect(localBounds), layer->layoutObject()).enclosingBoundingBox());
            if (layer->layoutObject()->hasOverflowClip())
                gapRectsBounds.move(layer->layoutBox()->scrolledContentOffset());
        }
        layer->addBlockSelectionGapsBounds(gapRectsBounds);
    }
}

void LayoutTextControlSingleLine::paint(const PaintInfo& paintInfo, const LayoutPoint& paintOffset) const
{
    LayoutTextControl::paint(paintInfo, paintOffset);

    if (shouldPaintSelfBlockBackground(paintInfo.phase) && m_shouldDrawCapsLockIndicator) {
        if (LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(paintInfo.context, *this, paintInfo.phase, paintOffset))
            return;

        LayoutRect contentsRect = contentBoxRect();

        // Center in the block progression direction.
        if (isHorizontalWritingMode())
            contentsRect.setY((size().height() - contentsRect.height()) / 2);
        else
            contentsRect.setX((size().width() - contentsRect.width()) / 2);

        // Convert the rect into the coords used for painting the content
        contentsRect.moveBy(paintOffset + location());
        IntRect snappedRect = pixelSnappedIntRect(contentsRect);
        LayoutObjectDrawingRecorder recorder(paintInfo.context, *this, paintInfo.phase, snappedRect, paintOffset);
        LayoutTheme::theme().painter().paintCapsLockIndicator(*this, paintInfo, snappedRect);
    }
}

static void buildRendererHighlight(RenderObject* renderer, RenderRegion* region, const HighlightConfig& highlightConfig, Highlight* highlight, InspectorOverlay::CoordinateSystem coordinateSystem)
{
    Frame* containingFrame = renderer->document().frame();
    if (!containingFrame)
        return;

    highlight->setDataFromConfig(highlightConfig);
    FrameView* containingView = containingFrame->view();
    FrameView* mainView = containingFrame->page()->mainFrame().view();

    // RenderSVGRoot should be highlighted through the isBox() code path, all other SVG elements should just dump their absoluteQuads().
    bool isSVGRenderer = renderer->node() && renderer->node()->isSVGElement() && !renderer->isSVGRoot();

    if (isSVGRenderer) {
        highlight->type = HighlightTypeRects;
        renderer->absoluteQuads(highlight->quads);
        for (size_t i = 0; i < highlight->quads.size(); ++i)
            contentsQuadToCoordinateSystem(mainView, containingView, highlight->quads[i], coordinateSystem);
    } else if (renderer->isBox() || renderer->isRenderInline()) {
        LayoutRect contentBox;
        LayoutRect paddingBox;
        LayoutRect borderBox;
        LayoutRect marginBox;

        if (renderer->isBox()) {
            RenderBox* renderBox = toRenderBox(renderer);

            LayoutBoxExtent margins(renderBox->marginTop(), renderBox->marginRight(), renderBox->marginBottom(), renderBox->marginLeft());

            if (!renderBox->isOutOfFlowPositioned() && region) {
                RenderBox::LogicalExtentComputedValues computedValues;
                renderBox->computeLogicalWidthInRegion(computedValues, region);
                margins.mutableLogicalLeft(renderBox->style().writingMode()) = computedValues.m_margins.m_start;
                margins.mutableLogicalRight(renderBox->style().writingMode()) = computedValues.m_margins.m_end;
            }

            paddingBox = renderBox->clientBoxRectInRegion(region);
            contentBox = LayoutRect(paddingBox.x() + renderBox->paddingLeft(), paddingBox.y() + renderBox->paddingTop(),
                paddingBox.width() - renderBox->paddingLeft() - renderBox->paddingRight(), paddingBox.height() - renderBox->paddingTop() - renderBox->paddingBottom());
            borderBox = LayoutRect(paddingBox.x() - renderBox->borderLeft(), paddingBox.y() - renderBox->borderTop(),
                paddingBox.width() + renderBox->borderLeft() + renderBox->borderRight(), paddingBox.height() + renderBox->borderTop() + renderBox->borderBottom());
            marginBox = LayoutRect(borderBox.x() - margins.left(), borderBox.y() - margins.top(),
                borderBox.width() + margins.left() + margins.right(), borderBox.height() + margins.top() + margins.bottom());
        } else {
            RenderInline* renderInline = toRenderInline(renderer);

            // RenderInline's bounding box includes paddings and borders, excludes margins.
            borderBox = renderInline->linesBoundingBox();
            paddingBox = LayoutRect(borderBox.x() + renderInline->borderLeft(), borderBox.y() + renderInline->borderTop(),
                borderBox.width() - renderInline->borderLeft() - renderInline->borderRight(), borderBox.height() - renderInline->borderTop() - renderInline->borderBottom());
            contentBox = LayoutRect(paddingBox.x() + renderInline->paddingLeft(), paddingBox.y() + renderInline->paddingTop(),
                paddingBox.width() - renderInline->paddingLeft() - renderInline->paddingRight(), paddingBox.height() - renderInline->paddingTop() - renderInline->paddingBottom());
            // Ignore marginTop and marginBottom for inlines.
            marginBox = LayoutRect(borderBox.x() - renderInline->marginLeft(), borderBox.y(),
                borderBox.width() + renderInline->horizontalMarginExtent(), borderBox.height());
        }

        FloatQuad absContentQuad;
        FloatQuad absPaddingQuad;
        FloatQuad absBorderQuad;
        FloatQuad absMarginQuad;

        if (region) {
            RenderFlowThread* flowThread = region->flowThread();

            // Figure out the quads in the space of the RenderFlowThread.
            absContentQuad = renderer->localToContainerQuad(FloatRect(contentBox), flowThread);
            absPaddingQuad = renderer->localToContainerQuad(FloatRect(paddingBox), flowThread);
            absBorderQuad = renderer->localToContainerQuad(FloatRect(borderBox), flowThread);
            absMarginQuad = renderer->localToContainerQuad(FloatRect(marginBox), flowThread);

            // Move the quad relative to the space of the current region.
            LayoutRect flippedRegionRect(region->flowThreadPortionRect());
            flowThread->flipForWritingMode(flippedRegionRect);

            FloatSize delta = region->contentBoxRect().location() - flippedRegionRect.location();
            absContentQuad.move(delta);
            absPaddingQuad.move(delta);
            absBorderQuad.move(delta);
            absMarginQuad.move(delta);

            // Resolve the absolute quads starting from the current region.
            absContentQuad = region->localToAbsoluteQuad(absContentQuad);
            absPaddingQuad = region->localToAbsoluteQuad(absPaddingQuad);
            absBorderQuad = region->localToAbsoluteQuad(absBorderQuad);
            absMarginQuad = region->localToAbsoluteQuad(absMarginQuad);
        } else {
            absContentQuad = renderer->localToAbsoluteQuad(FloatRect(contentBox));
            absPaddingQuad = renderer->localToAbsoluteQuad(FloatRect(paddingBox));
            absBorderQuad = renderer->localToAbsoluteQuad(FloatRect(borderBox));
            absMarginQuad = renderer->localToAbsoluteQuad(FloatRect(marginBox));
        }

        contentsQuadToCoordinateSystem(mainView, containingView, absContentQuad, coordinateSystem);
        contentsQuadToCoordinateSystem(mainView, containingView, absPaddingQuad, coordinateSystem);
        contentsQuadToCoordinateSystem(mainView, containingView, absBorderQuad, coordinateSystem);
        contentsQuadToCoordinateSystem(mainView, containingView, absMarginQuad, coordinateSystem);

        highlight->type = HighlightTypeNode;
        highlight->quads.append(absMarginQuad);
//.........这里部分代码省略.........

static PassRefPtr<InspectorObject> buildObjectForRegionHighlight(FrameView* mainView, RenderRegion* region)
{
    FrameView* containingView = region->frame().view();
    if (!containingView)
        return nullptr;

    RenderBlockFlow* regionContainer = toRenderBlockFlow(region->parent());
    LayoutRect borderBox = regionContainer->borderBoxRect();
    borderBox.setWidth(borderBox.width() + regionContainer->verticalScrollbarWidth());
    borderBox.setHeight(borderBox.height() + regionContainer->horizontalScrollbarHeight());

    // Create incoming and outgoing boxes that we use to chain the regions toghether.
    const LayoutSize linkBoxSize(10, 10);
    const LayoutSize linkBoxMidpoint(linkBoxSize.width() / 2, linkBoxSize.height() / 2);
    
    LayoutRect incomingRectBox = LayoutRect(borderBox.location() - linkBoxMidpoint, linkBoxSize);
    LayoutRect outgoingRectBox = LayoutRect(borderBox.location() - linkBoxMidpoint + borderBox.size(), linkBoxSize);

    // Move the link boxes slightly inside the region border box.
    LayoutUnit maxUsableHeight = std::max(LayoutUnit(), borderBox.height() - linkBoxMidpoint.height());
    LayoutUnit linkBoxVerticalOffset = std::min(LayoutUnit::fromPixel(15), maxUsableHeight);
    incomingRectBox.move(0, linkBoxVerticalOffset);
    outgoingRectBox.move(0, -linkBoxVerticalOffset);

    FloatQuad borderRectQuad = regionContainer->localToAbsoluteQuad(FloatRect(borderBox));
    FloatQuad incomingRectQuad = regionContainer->localToAbsoluteQuad(FloatRect(incomingRectBox));
    FloatQuad outgoingRectQuad = regionContainer->localToAbsoluteQuad(FloatRect(outgoingRectBox));

    contentsQuadToPage(mainView, containingView, borderRectQuad);
    contentsQuadToPage(mainView, containingView, incomingRectQuad);
    contentsQuadToPage(mainView, containingView, outgoingRectQuad);

    RefPtr<InspectorObject> regionObject = InspectorObject::create();

    regionObject->setArray("borderQuad", buildArrayForQuad(borderRectQuad));
    regionObject->setArray("incomingQuad", buildArrayForQuad(incomingRectQuad));
    regionObject->setArray("outgoingQuad", buildArrayForQuad(outgoingRectQuad));

    return regionObject.release();
}

LayoutRect LayoutMultiColumnSet::overflowRectForFlowThreadPortion(const LayoutRect& flowThreadPortionRect, bool isFirstPortion, bool isLastPortion) const
{
    if (hasOverflowClip())
        return flowThreadPortionRect;

    LayoutRect flowThreadOverflow = m_flowThread->visualOverflowRect();

    // Only clip along the flow thread axis.
    LayoutRect clipRect;
    if (m_flowThread->isHorizontalWritingMode()) {
        LayoutUnit minY = isFirstPortion ? flowThreadOverflow.y() : flowThreadPortionRect.y();
        LayoutUnit maxY = isLastPortion ? std::max(flowThreadPortionRect.maxY(), flowThreadOverflow.maxY()) : flowThreadPortionRect.maxY();
        LayoutUnit minX = std::min(flowThreadPortionRect.x(), flowThreadOverflow.x());
        LayoutUnit maxX = std::max(flowThreadPortionRect.maxX(), flowThreadOverflow.maxX());
        clipRect = LayoutRect(minX, minY, maxX - minX, maxY - minY);
    } else {
        LayoutUnit minX = isFirstPortion ? flowThreadOverflow.x() : flowThreadPortionRect.x();
        LayoutUnit maxX = isLastPortion ? std::max(flowThreadPortionRect.maxX(), flowThreadOverflow.maxX()) : flowThreadPortionRect.maxX();
        LayoutUnit minY = std::min(flowThreadPortionRect.y(), (flowThreadOverflow.y()));
        LayoutUnit maxY = std::max(flowThreadPortionRect.y(), (flowThreadOverflow.maxY()));
        clipRect = LayoutRect(minX, minY, maxX - minX, maxY - minY);
    }

    return clipRect;
}

LayoutRect RenderReplaced::replacedContentRect(const LayoutSize& intrinsicSize) const
{
    LayoutRect contentRect = contentBoxRect();
    ObjectFit objectFit = style().objectFit();
    if (objectFit == ObjectFitFill)
        return contentRect;

    if (!intrinsicSize.width() || !intrinsicSize.height())
        return contentRect;

    LayoutRect finalRect = contentRect;
    switch (objectFit) {
    case ObjectFitContain:
    case ObjectFitScaleDown:
    case ObjectFitCover:
        finalRect.setSize(finalRect.size().fitToAspectRatio(intrinsicSize, objectFit == ObjectFitCover ? AspectRatioFitGrow : AspectRatioFitShrink));
        if (objectFit != ObjectFitScaleDown || finalRect.width() <= intrinsicSize.width())
            break;
        // fall through
    case ObjectFitNone:
        finalRect.setSize(intrinsicSize);
        break;
    case ObjectFitFill:
        ASSERT_NOT_REACHED();
    }

    // FIXME: This is where object-position should be taken into account, but since it's not
    // implemented yet, assume the initial value of "50% 50%".
    LayoutUnit xOffset = (contentRect.width() - finalRect.width()) / 2;
    LayoutUnit yOffset = (contentRect.height() - finalRect.height()) / 2;
    finalRect.move(xOffset, yOffset);

    return finalRect;
}

IntRect::IntRect(const LayoutRect& r)
    : m_location(r.x(), r.y())
    , m_size(r.width(), r.height())
{
}

void IntersectionObserver::applyRootMargin(LayoutRect& rect) const
{
    // TODO(szager): Make sure the spec is clear that left/right margins are resolved against
    // width and not height.
    LayoutUnit topMargin = computeMargin(m_topMargin, rect.height());
    LayoutUnit rightMargin = computeMargin(m_rightMargin, rect.width());
    LayoutUnit bottomMargin = computeMargin(m_bottomMargin, rect.height());
    LayoutUnit leftMargin = computeMargin(m_leftMargin, rect.width());

    rect.setX(rect.x() - leftMargin);
    rect.setWidth(rect.width() + leftMargin + rightMargin);
    rect.setY(rect.y() - topMargin);
    rect.setHeight(rect.height() + topMargin + bottomMargin);
}

LayoutRect RenderNamedFlowFragment::flowThreadPortionRectForClipping(bool isFirstRegionInRange, bool isLastRegionInRange) const
{
    // Elements flowed into a region should not be painted past the region's content box
    // if they continue to flow into another region in that direction.
    // If they do not continue into another region in that direction, they should be
    // painted all the way to the region's border box.
    // Regions with overflow:hidden will apply clip at the border box, not the content box.
    
    LayoutRect clippingRect = flowThreadPortionRect();
    RenderBlockFlow& container = fragmentContainer();
    if (container.style().hasPadding()) {
        if (isFirstRegionInRange) {
            if (flowThread()->isHorizontalWritingMode()) {
                clippingRect.move(0, -container.paddingBefore());
                clippingRect.expand(0, container.paddingBefore());
            } else {
                clippingRect.move(-container.paddingBefore(), 0);
                clippingRect.expand(container.paddingBefore(), 0);
            }
        }
        
        if (isLastRegionInRange) {
            if (flowThread()->isHorizontalWritingMode())
                clippingRect.expand(0, container.paddingAfter());
            else
                clippingRect.expand(container.paddingAfter(), 0);
        }
        
        if (flowThread()->isHorizontalWritingMode()) {
            clippingRect.move(-container.paddingStart(), 0);
            clippingRect.expand(container.paddingStart() + container.paddingEnd(), 0);
        } else {
            clippingRect.move(0, -container.paddingStart());
            clippingRect.expand(0, container.paddingStart() + container.paddingEnd());
        }
    }
    
    return clippingRect;
}