C++ LayoutRect::isEmpty方法代码示例

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 RenderReplaced::paint(PaintInfo& paintInfo, const LayoutPoint& paintOffset, Vector<RenderBox*>& layers)
{
    if (!shouldPaint(paintInfo, paintOffset))
        return;

    LayoutPoint adjustedPaintOffset = paintOffset + location();

    if (hasBoxDecorationBackground())
        paintBoxDecorationBackground(paintInfo, adjustedPaintOffset);

    LayoutRect paintRect = LayoutRect(adjustedPaintOffset, size());

    bool completelyClippedOut = false;
    if (style()->hasBorderRadius()) {
        LayoutRect borderRect = LayoutRect(adjustedPaintOffset, size());

        if (borderRect.isEmpty())
            completelyClippedOut = true;
        else {
            // Push a clip if we have a border radius, since we want to round the foreground content that gets painted.
            paintInfo.context->save();
            RoundedRect roundedInnerRect = style()->getRoundedInnerBorderFor(paintRect,
                paddingTop() + borderTop(), paddingBottom() + borderBottom(), paddingLeft() + borderLeft(), paddingRight() + borderRight(), true, true);
            clipRoundedInnerRect(paintInfo.context, paintRect, roundedInnerRect);
        }
    }

    if (!completelyClippedOut) {
        paintReplaced(paintInfo, adjustedPaintOffset);
        if (style()->hasBorderRadius())
            paintInfo.context->restore();
    }

    // The selection tint never gets clipped by border-radius rounding, since we want it to run right up to the edges of
    // surrounding content.
    if (selectionState() != SelectionNone) {
        LayoutRect selectionPaintingRect = localSelectionRect();
        selectionPaintingRect.moveBy(adjustedPaintOffset);
        paintInfo.context->fillRect(pixelSnappedIntRect(selectionPaintingRect), selectionBackgroundColor());
    }
}

LayoutRect AccessibilityObject::boundingBoxForQuads(RenderObject* obj, const Vector<FloatQuad>& quads)
{
    ASSERT(obj);
    if (!obj)
        return LayoutRect();
    
    size_t count = quads.size();
    if (!count)
        return LayoutRect();
    
    LayoutRect result;
    for (size_t i = 0; i < count; ++i) {
        LayoutRect r = quads[i].enclosingBoundingBox();
        if (!r.isEmpty()) {
            if (obj->style()->hasAppearance())
                obj->theme()->adjustRepaintRect(obj, r);
            result.unite(r);
        }
    }
    return result;
}

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);
    }
}

bool FilterEffectRendererHelper::prepareFilterEffect(RenderLayer* renderLayer, const LayoutRect& filterBoxRect, const LayoutRect& dirtyRect, const LayoutRect& layerRepaintRect)
{
    ASSERT(m_haveFilterEffect && renderLayer->filterRenderer());
    m_renderLayer = renderLayer;
    m_repaintRect = dirtyRect;

    FilterEffectRenderer* filter = renderLayer->filterRenderer();
    LayoutRect filterSourceRect = filter->computeSourceImageRectForDirtyRect(filterBoxRect, dirtyRect);

    if (filterSourceRect.isEmpty()) {
        // The dirty rect is not in view, just bail out.
        m_haveFilterEffect = false;
        return false;
    }

    // Get the zoom factor to scale the filterSourceRect input
    const RenderLayerModelObject* renderer = renderLayer->renderer();
    const RenderStyle* style = renderer ? renderer->style() : 0;
    float zoom = style ? style->effectiveZoom() : 1.0f;

    AffineTransform absoluteTransform;
    absoluteTransform.translate(filterBoxRect.x(), filterBoxRect.y());
    filter->setAbsoluteTransform(absoluteTransform);
    filter->setAbsoluteFilterRegion(AffineTransform().scale(zoom).mapRect(filterSourceRect));
    filter->setFilterRegion(absoluteTransform.inverse().mapRect(filterSourceRect));
    filter->lastEffect()->determineFilterPrimitiveSubregion();

    bool hasUpdatedBackingStore = filter->updateBackingStoreRect(filterSourceRect);
    if (filter->hasFilterThatMovesPixels()) {
        if (hasUpdatedBackingStore)
            m_repaintRect = filterSourceRect;
        else {
            m_repaintRect.unite(layerRepaintRect);
            m_repaintRect.intersect(filterSourceRect);
        }
    }
    return true;
}

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

    if (!displayingPoster) {
        if (!mediaPlayer)
            return;
        updatePlayer();
    }

    LayoutRect rect = videoBox();
    if (rect.isEmpty())
        return;
    rect.moveBy(paintOffset);

    if (displayingPoster)
        paintIntoRect(paintInfo.context, rect);
    else if (document()->view() && document()->view()->paintBehavior() & PaintBehaviorFlattenCompositingLayers)
        mediaPlayer->paintCurrentFrameInContext(paintInfo.context, rect);
    else
        mediaPlayer->paint(paintInfo.context, rect);
}

void CaretBase::paintCaret(Node* node, GraphicsContext* context, const LayoutPoint& paintOffset, const LayoutRect& clipRect) const
{
    if (m_caretVisibility == Hidden)
        return;

    LayoutRect drawingRect = localCaretRectWithoutUpdate();
    drawingRect.moveBy(roundedIntPoint(paintOffset));
    LayoutRect caret = intersection(drawingRect, clipRect);
    if (caret.isEmpty())
        return;

    Color caretColor = Color::black;

    Element* element;
    if (node->isElementNode())
        element = toElement(node);
    else
        element = node->parentElement();

    if (element && element->renderer())
        caretColor = element->renderer()->resolveColor(CSSPropertyColor);

    context->fillRect(caret, caretColor);
}

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

    Page* page = 0;
    if (Frame* frame = this->frame())
        page = frame->page();

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

    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);

    if (displayingPoster)
        paintIntoRect(paintInfo.context, rect);
    else if (document()->view() && document()->view()->paintBehavior() & PaintBehaviorFlattenCompositingLayers)
        mediaPlayer->paintCurrentFrameInContext(paintInfo.context, pixelSnappedIntRect(rect));
    else
        mediaPlayer->paint(paintInfo.context, pixelSnappedIntRect(rect));
}

bool RenderEmbeddedObject::isReplacementObscured() const
{
    // Return whether or not the replacement content for blocked plugins is accessible to the user.

    // Check the opacity of each layer containing the element or its ancestors.
    float opacity = 1.0;
    for (RenderLayer* layer = enclosingLayer(); layer; layer = layer->parent()) {
        opacity *= layer->renderer().style().opacity();
        if (opacity < 0.1)
            return true;
    }

    // Calculate the absolute rect for the blocked plugin replacement text.
    IntRect absoluteBoundingBox = absoluteBoundingBoxRect();
    LayoutPoint absoluteLocation(absoluteBoundingBox.location());
    LayoutRect rect = unavailablePluginIndicatorBounds(absoluteLocation);
    if (rect.isEmpty())
        return true;

    RenderView* rootRenderView = document().topDocument().renderView();
    ASSERT(rootRenderView);
    if (!rootRenderView)
        return true;

    IntRect rootViewRect = view().frameView().convertToRootView(snappedIntRect(rect));
    
    HitTestRequest request(HitTestRequest::ReadOnly | HitTestRequest::Active | HitTestRequest::IgnoreClipping | HitTestRequest::DisallowUserAgentShadowContent | HitTestRequest::AllowChildFrameContent);
    HitTestResult result;
    HitTestLocation location;
    
    LayoutUnit x = rootViewRect.x();
    LayoutUnit y = rootViewRect.y();
    LayoutUnit width = rootViewRect.width();
    LayoutUnit height = rootViewRect.height();
    
    // Hit test the center and near the corners of the replacement text to ensure
    // it is visible and is not masked by other elements.
    bool hit = false;
    location = LayoutPoint(x + width / 2, y + height / 2);
    hit = rootRenderView->hitTest(request, location, result);
    if (!hit || result.innerNode() != &frameOwnerElement())
        return true;
    
    location = LayoutPoint(x, y);
    hit = rootRenderView->hitTest(request, location, result);
    if (!hit || result.innerNode() != &frameOwnerElement())
        return true;
    
    location = LayoutPoint(x + width, y);
    hit = rootRenderView->hitTest(request, location, result);
    if (!hit || result.innerNode() != &frameOwnerElement())
        return true;
    
    location = LayoutPoint(x + width, y + height);
    hit = rootRenderView->hitTest(request, location, result);
    if (!hit || result.innerNode() != &frameOwnerElement())
        return true;
    
    location = LayoutPoint(x, y + height);
    hit = rootRenderView->hitTest(request, location, result);
    if (!hit || result.innerNode() != &frameOwnerElement())
        return true;

    return false;
}

bool LayoutRect::intersects(const LayoutRect& other) const {
  // Checking emptiness handles negative widths as well as zero.
  return !isEmpty() && !other.isEmpty() && x() < other.maxX() &&
         other.x() < maxX() && y() < other.maxY() && other.y() < maxY();
}

// addFocusRingRects is called from paintOutline and needs to be in the same coordinates as the paintOuline call
void RenderSVGContainer::addFocusRingRects(Vector<LayoutRect>& rects, const LayoutPoint&, const RenderLayerModelObject*) const
{
    LayoutRect paintRectInParent = LayoutRect(localToParentTransform().mapRect(paintInvalidationRectInLocalCoordinates()));
    if (!paintRectInParent.isEmpty())
        rects.append(paintRectInParent);
}

void RenderReplaced::paint(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
{
    ANNOTATE_GRAPHICS_CONTEXT(paintInfo, this);

    if (!shouldPaint(paintInfo, paintOffset))
        return;

    LayoutPoint adjustedPaintOffset = paintOffset + location();

    if (hasBoxDecorations() && (paintInfo.phase == PaintPhaseForeground || paintInfo.phase == PaintPhaseSelection))
        paintBoxDecorations(paintInfo, adjustedPaintOffset);

    if (paintInfo.phase == PaintPhaseMask) {
        paintMask(paintInfo, adjustedPaintOffset);
        return;
    }

    LayoutRect paintRect = LayoutRect(adjustedPaintOffset, size());
    if ((paintInfo.phase == PaintPhaseOutline || paintInfo.phase == PaintPhaseSelfOutline) && style()->outlineWidth())
        paintOutline(paintInfo, paintRect);

    if (paintInfo.phase != PaintPhaseForeground && paintInfo.phase != PaintPhaseSelection && !canHaveChildren())
        return;

    if (!paintInfo.shouldPaintWithinRoot(this))
        return;

    bool drawSelectionTint = selectionState() != SelectionNone && !document()->printing();
    if (paintInfo.phase == PaintPhaseSelection) {
        if (selectionState() == SelectionNone)
            return;
        drawSelectionTint = false;
    }

    bool completelyClippedOut = false;
    if (style()->hasBorderRadius()) {
        LayoutRect borderRect = LayoutRect(adjustedPaintOffset, size());

        if (borderRect.isEmpty())
            completelyClippedOut = true;
        else {
            // Push a clip if we have a border radius, since we want to round the foreground content that gets painted.
            paintInfo.context->save();
            RoundedRect roundedInnerRect = style()->getRoundedInnerBorderFor(paintRect,
                paddingTop() + borderTop(), paddingBottom() + borderBottom(), paddingLeft() + borderLeft(), paddingRight() + borderRight(), true, true);
            clipRoundedInnerRect(paintInfo.context, paintRect, roundedInnerRect);
        }
    }

    if (!completelyClippedOut) {
        paintReplaced(paintInfo, adjustedPaintOffset);

        if (style()->hasBorderRadius())
            paintInfo.context->restore();
    }

    // The selection tint never gets clipped by border-radius rounding, since we want it to run right up to the edges of
    // surrounding content.
    if (drawSelectionTint) {
        LayoutRect selectionPaintingRect = localSelectionRect();
        selectionPaintingRect.moveBy(adjustedPaintOffset);
        paintInfo.context->fillRect(pixelSnappedIntRect(selectionPaintingRect), selectionBackgroundColor());
    }
}

// This method is called from inside paintOutline() since we call paintOutline()
// while transformed to our coord system, return local coords
void RenderSVGShape::addFocusRingRects(Vector<LayoutRect>& rects, const LayoutPoint&, const RenderLayerModelObject*)
{
    LayoutRect rect = LayoutRect(repaintRectInLocalCoordinates());
    if (!rect.isEmpty())
        rects.append(rect);
}

void InlinePainter::paintOutlineForLine(GraphicsContext* graphicsContext, const LayoutPoint& paintOffset,
    const LayoutRect& lastline, const LayoutRect& thisline, const LayoutRect& nextline, const Color outlineColor)
{
    RenderStyle* styleToUse = m_renderInline.style();
    int outlineWidth = styleToUse->outlineWidth();
    EBorderStyle outlineStyle = styleToUse->outlineStyle();

    bool antialias = BoxPainter::shouldAntialiasLines(graphicsContext);

    int offset = m_renderInline.style()->outlineOffset();

    LayoutRect box(LayoutPoint(paintOffset.x() + thisline.x() - offset, paintOffset.y() + thisline.y() - offset),
        LayoutSize(thisline.width() + offset, thisline.height() + offset));

    IntRect pixelSnappedBox = pixelSnappedIntRect(box);
    if (pixelSnappedBox.width() < 0 || pixelSnappedBox.height() < 0)
        return;
    IntRect pixelSnappedLastLine = pixelSnappedIntRect(paintOffset.x() + lastline.x(), 0, lastline.width(), 0);
    IntRect pixelSnappedNextLine = pixelSnappedIntRect(paintOffset.x() + nextline.x(), 0, nextline.width(), 0);

    // left edge
    ObjectPainter::drawLineForBoxSide(graphicsContext,
        pixelSnappedBox.x() - outlineWidth,
        pixelSnappedBox.y() - (lastline.isEmpty() || thisline.x() < lastline.x() || (lastline.maxX() - 1) <= thisline.x() ? outlineWidth : 0),
        pixelSnappedBox.x(),
        pixelSnappedBox.maxY() + (nextline.isEmpty() || thisline.x() <= nextline.x() || (nextline.maxX() - 1) <= thisline.x() ? outlineWidth : 0),
        BSLeft,
        outlineColor, outlineStyle,
        (lastline.isEmpty() || thisline.x() < lastline.x() || (lastline.maxX() - 1) <= thisline.x() ? outlineWidth : -outlineWidth),
        (nextline.isEmpty() || thisline.x() <= nextline.x() || (nextline.maxX() - 1) <= thisline.x() ? outlineWidth : -outlineWidth),
        antialias);

    // right edge
    ObjectPainter::drawLineForBoxSide(graphicsContext,
        pixelSnappedBox.maxX(),
        pixelSnappedBox.y() - (lastline.isEmpty() || lastline.maxX() < thisline.maxX() || (thisline.maxX() - 1) <= lastline.x() ? outlineWidth : 0),
        pixelSnappedBox.maxX() + outlineWidth,
        pixelSnappedBox.maxY() + (nextline.isEmpty() || nextline.maxX() <= thisline.maxX() || (thisline.maxX() - 1) <= nextline.x() ? outlineWidth : 0),
        BSRight,
        outlineColor, outlineStyle,
        (lastline.isEmpty() || lastline.maxX() < thisline.maxX() || (thisline.maxX() - 1) <= lastline.x() ? outlineWidth : -outlineWidth),
        (nextline.isEmpty() || nextline.maxX() <= thisline.maxX() || (thisline.maxX() - 1) <= nextline.x() ? outlineWidth : -outlineWidth),
        antialias);
    // upper edge
    if (thisline.x() < lastline.x()) {
        ObjectPainter::drawLineForBoxSide(graphicsContext,
            pixelSnappedBox.x() - outlineWidth,
            pixelSnappedBox.y() - outlineWidth,
            std::min(pixelSnappedBox.maxX() + outlineWidth, (lastline.isEmpty() ? 1000000 : pixelSnappedLastLine.x())),
            pixelSnappedBox.y(),
            BSTop, outlineColor, outlineStyle,
            outlineWidth,
            (!lastline.isEmpty() && paintOffset.x() + lastline.x() + 1 < pixelSnappedBox.maxX() + outlineWidth) ? -outlineWidth : outlineWidth,
            antialias);
    }

    if (lastline.maxX() < thisline.maxX()) {
        ObjectPainter::drawLineForBoxSide(graphicsContext,
            std::max(lastline.isEmpty() ? -1000000 : pixelSnappedLastLine.maxX(), pixelSnappedBox.x() - outlineWidth),
            pixelSnappedBox.y() - outlineWidth,
            pixelSnappedBox.maxX() + outlineWidth,
            pixelSnappedBox.y(),
            BSTop, outlineColor, outlineStyle,
            (!lastline.isEmpty() && pixelSnappedBox.x() - outlineWidth < paintOffset.x() + lastline.maxX()) ? -outlineWidth : outlineWidth,
            outlineWidth, antialias);
    }

    if (thisline.x() == thisline.maxX()) {
        ObjectPainter::drawLineForBoxSide(graphicsContext,
            pixelSnappedBox.x() - outlineWidth,
            pixelSnappedBox.y() - outlineWidth,
            pixelSnappedBox.maxX() + outlineWidth,
            pixelSnappedBox.y(),
            BSTop, outlineColor, outlineStyle,
            outlineWidth,
            outlineWidth,
            antialias);
    }

    // lower edge
    if (thisline.x() < nextline.x()) {
        ObjectPainter::drawLineForBoxSide(graphicsContext,
            pixelSnappedBox.x() - outlineWidth,
            pixelSnappedBox.maxY(),
            std::min(pixelSnappedBox.maxX() + outlineWidth, !nextline.isEmpty() ? pixelSnappedNextLine.x() + 1 : 1000000),
            pixelSnappedBox.maxY() + outlineWidth,
            BSBottom, outlineColor, outlineStyle,
            outlineWidth,
            (!nextline.isEmpty() && paintOffset.x() + nextline.x() + 1 < pixelSnappedBox.maxX() + outlineWidth) ? -outlineWidth : outlineWidth,
            antialias);
    }

    if (nextline.maxX() < thisline.maxX()) {
        ObjectPainter::drawLineForBoxSide(graphicsContext,
            std::max(!nextline.isEmpty() ? pixelSnappedNextLine.maxX() : -1000000, pixelSnappedBox.x() - outlineWidth),
            pixelSnappedBox.maxY(),
            pixelSnappedBox.maxX() + outlineWidth,
            pixelSnappedBox.maxY() + outlineWidth,
            BSBottom, outlineColor, outlineStyle,
            (!nextline.isEmpty() && pixelSnappedBox.x() - outlineWidth < paintOffset.x() + nextline.maxX()) ? -outlineWidth : outlineWidth,
//.........这里部分代码省略.........

void InlinePainter::paintOutlineForLine(GraphicsContext* graphicsContext, const LayoutPoint& paintOffset,
    const LayoutRect& lastline, const LayoutRect& thisline, const LayoutRect& nextline, const Color outlineColor)
{
    const ComputedStyle& styleToUse = m_layoutInline.styleRef();
    int outlineWidth = styleToUse.outlineWidth();
    EBorderStyle outlineStyle = styleToUse.outlineStyle();

    bool antialias = BoxPainter::shouldAntialiasLines(graphicsContext);

    int offset = m_layoutInline.style()->outlineOffset();

    LayoutRect box(LayoutPoint(paintOffset.x() + thisline.x() - offset, paintOffset.y() + thisline.y() - offset),
        LayoutSize(thisline.width() + offset, thisline.height() + offset));

    IntRect pixelSnappedBox = pixelSnappedIntRect(box);
    if (pixelSnappedBox.width() < 0 || pixelSnappedBox.height() < 0)
        return;
    // Note that we use IntRect below for working with solely x/width values, simplifying logic at cost of a bit of memory.
    IntRect pixelSnappedLastLine = pixelSnappedIntRect(paintOffset.x() + lastline.x() - offset, 0, lastline.width() + offset, 0);
    IntRect pixelSnappedNextLine = pixelSnappedIntRect(paintOffset.x() + nextline.x() - offset, 0, nextline.width() + offset, 0);

    const int fallbackMaxOutlineX = std::numeric_limits<int>::max();
    const int fallbackMinOutlineX = std::numeric_limits<int>::min();

    // left edge
    ObjectPainter::drawLineForBoxSide(graphicsContext,
        pixelSnappedBox.x() - outlineWidth,
        pixelSnappedBox.y() - (lastline.isEmpty() || thisline.x() < lastline.x() || (lastline.maxX() - 1) <= thisline.x() ? outlineWidth : 0),
        pixelSnappedBox.x(),
        pixelSnappedBox.maxY() + (nextline.isEmpty() || thisline.x() <= nextline.x() || (nextline.maxX() - 1) <= thisline.x() ? outlineWidth : 0),
        BSLeft,
        outlineColor, outlineStyle,
        (lastline.isEmpty() || thisline.x() < lastline.x() || (lastline.maxX() - 1) <= thisline.x() ? outlineWidth : -outlineWidth),
        (nextline.isEmpty() || thisline.x() <= nextline.x() || (nextline.maxX() - 1) <= thisline.x() ? outlineWidth : -outlineWidth),
        antialias);

    // right edge
    ObjectPainter::drawLineForBoxSide(graphicsContext,
        pixelSnappedBox.maxX(),
        pixelSnappedBox.y() - (lastline.isEmpty() || lastline.maxX() < thisline.maxX() || (thisline.maxX() - 1) <= lastline.x() ? outlineWidth : 0),
        pixelSnappedBox.maxX() + outlineWidth,
        pixelSnappedBox.maxY() + (nextline.isEmpty() || nextline.maxX() <= thisline.maxX() || (thisline.maxX() - 1) <= nextline.x() ? outlineWidth : 0),
        BSRight,
        outlineColor, outlineStyle,
        (lastline.isEmpty() || lastline.maxX() < thisline.maxX() || (thisline.maxX() - 1) <= lastline.x() ? outlineWidth : -outlineWidth),
        (nextline.isEmpty() || nextline.maxX() <= thisline.maxX() || (thisline.maxX() - 1) <= nextline.x() ? outlineWidth : -outlineWidth),
        antialias);
    // upper edge
    if (thisline.x() < lastline.x()) {
        ObjectPainter::drawLineForBoxSide(graphicsContext,
            pixelSnappedBox.x() - outlineWidth,
            pixelSnappedBox.y() - outlineWidth,
            std::min(pixelSnappedBox.maxX() + outlineWidth, (lastline.isEmpty() ? fallbackMaxOutlineX : pixelSnappedLastLine.x())),
            pixelSnappedBox.y(),
            BSTop, outlineColor, outlineStyle,
            outlineWidth,
            (!lastline.isEmpty() && paintOffset.x() + lastline.x() + 1 < pixelSnappedBox.maxX() + outlineWidth) ? -outlineWidth : outlineWidth,
            antialias);
    }

    if (lastline.maxX() < thisline.maxX()) {
        ObjectPainter::drawLineForBoxSide(graphicsContext,
            std::max(lastline.isEmpty() ? fallbackMinOutlineX : pixelSnappedLastLine.maxX(), pixelSnappedBox.x() - outlineWidth),
            pixelSnappedBox.y() - outlineWidth,
            pixelSnappedBox.maxX() + outlineWidth,
            pixelSnappedBox.y(),
            BSTop, outlineColor, outlineStyle,
            (!lastline.isEmpty() && pixelSnappedBox.x() - outlineWidth < paintOffset.x() + lastline.maxX()) ? -outlineWidth : outlineWidth,
            outlineWidth, antialias);
    }

    if (thisline.x() == thisline.maxX()) {
        ObjectPainter::drawLineForBoxSide(graphicsContext,
            pixelSnappedBox.x() - outlineWidth,
            pixelSnappedBox.y() - outlineWidth,
            pixelSnappedBox.maxX() + outlineWidth,
            pixelSnappedBox.y(),
            BSTop, outlineColor, outlineStyle,
            outlineWidth,
            outlineWidth,
            antialias);
    }

    // lower edge
    if (thisline.x() < nextline.x()) {
        ObjectPainter::drawLineForBoxSide(graphicsContext,
            pixelSnappedBox.x() - outlineWidth,
            pixelSnappedBox.maxY(),
            std::min(pixelSnappedBox.maxX() + outlineWidth, !nextline.isEmpty() ? pixelSnappedNextLine.x() + 1 : fallbackMaxOutlineX),
            pixelSnappedBox.maxY() + outlineWidth,
            BSBottom, outlineColor, outlineStyle,
            outlineWidth,
            (!nextline.isEmpty() && paintOffset.x() + nextline.x() + 1 < pixelSnappedBox.maxX() + outlineWidth) ? -outlineWidth : outlineWidth,
            antialias);
    }

    if (nextline.maxX() < thisline.maxX()) {
        ObjectPainter::drawLineForBoxSide(graphicsContext,
            std::max(!nextline.isEmpty() ? pixelSnappedNextLine.maxX() : fallbackMinOutlineX, pixelSnappedBox.x() - outlineWidth),
            pixelSnappedBox.maxY(),
//.........这里部分代码省略.........