// RenderBox methods will expect coordinates w/o any transforms in coordinates
// relative to our borderBox origin.  This method gives us exactly that.
void RenderSVGRoot::buildLocalToBorderBoxTransform()
{
    SVGSVGElement* svg = toSVGSVGElement(node());
    ASSERT(svg);
    float scale = style()->effectiveZoom();
    FloatPoint translate = svg->currentTranslate();
    LayoutSize borderAndPadding(borderLeft() + paddingLeft(), borderTop() + paddingTop());
    m_localToBorderBoxTransform = svg->viewBoxToViewTransform(contentWidth() / scale, contentHeight() / scale);
    if (borderAndPadding.isEmpty() && scale == 1 && translate == FloatPoint::zero())
        return;
    m_localToBorderBoxTransform = AffineTransform(scale, 0, 0, scale, borderAndPadding.width() + translate.x(), borderAndPadding.height() + translate.y()) * m_localToBorderBoxTransform;
}

void RenderWidget::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;
    }

    if ((paintInfo.phase == PaintPhaseOutline || paintInfo.phase == PaintPhaseSelfOutline) && hasOutline())
        paintOutline(paintInfo, LayoutRect(adjustedPaintOffset, size()));

    if (paintInfo.phase != PaintPhaseForeground)
        return;

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

        if (borderRect.isEmpty())
            return;

        // 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(borderRect,
            paddingTop() + borderTop(), paddingBottom() + borderBottom(), paddingLeft() + borderLeft(), paddingRight() + borderRight(), true, true);
        clipRoundedInnerRect(paintInfo.context, borderRect, roundedInnerRect);
    }

    Widget* widget = this->widget();
    if (widget)
        paintContents(paintInfo, paintOffset);

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

    // Paint a partially transparent wash over selected widgets.
    if (isSelected() && !document().printing()) {
        // FIXME: selectionRect() is in absolute, not painting coordinates.
        paintInfo.context->fillRect(pixelSnappedIntRect(selectionRect()), selectionBackgroundColor());
    }

    if (canResize())
        layer()->scrollableArea()->paintResizer(paintInfo.context, roundedIntPoint(adjustedPaintOffset), paintInfo.rect);
}

void RenderReplaced::calcMinMaxWidth()
{
    ASSERT(!minMaxKnown());

    int width = calcReplacedWidth() + paddingLeft() + paddingRight() + borderLeft() + borderRight();
    if (style()->width().isPercent() || (style()->width().isAuto() && style()->height().isPercent())) {
        m_minWidth = 0;
        m_maxWidth = width;
    } else
        m_minWidth = m_maxWidth = width;

    setMinMaxKnown();
}

void RenderReplaced::calcPrefWidths()
{
    ASSERT(prefWidthsDirty());

    int width = calcReplacedWidth() + paddingLeft() + paddingRight() + borderLeft() + borderRight();
    if (style()->width().isPercent() || (style()->width().isAuto() && style()->height().isPercent())) {
        m_minPrefWidth = 0;
        m_maxPrefWidth = width;
    } else
        m_minPrefWidth = m_maxPrefWidth = width;

    setPrefWidthsDirty(false);
}

LayoutObject* LayoutTextControlMultiLine::layoutSpecialExcludedChild(bool relayoutChildren, SubtreeLayoutScope& layoutScope)
{
    LayoutObject* placeholderLayoutObject = LayoutTextControl::layoutSpecialExcludedChild(relayoutChildren, layoutScope);
    if (!placeholderLayoutObject)
        return nullptr;
    if (!placeholderLayoutObject->isBox())
        return placeholderLayoutObject;
    LayoutBox* placeholderBox = toLayoutBox(placeholderLayoutObject);
    placeholderBox->mutableStyleRef().setLogicalWidth(Length(contentLogicalWidth() - placeholderBox->borderAndPaddingLogicalWidth(), Fixed));
    placeholderBox->layoutIfNeeded();
    placeholderBox->setX(borderLeft() + paddingLeft());
    placeholderBox->setY(borderTop() + paddingTop());
    return placeholderLayoutObject;
}

// Hit Testing
bool RenderRegion::hitTestFlowThreadContents(const HitTestRequest& request, HitTestResult& result, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction action)
{
    if (!isValid() || action != HitTestForeground)
        return false;

    LayoutRect boundsRect = borderBoxRectInRegion(locationInContainer.region());
    boundsRect.moveBy(accumulatedOffset);
    if (visibleToHitTesting() && locationInContainer.intersects(boundsRect)) {
        if (m_flowThread->hitTestFlowThreadPortionInRegion(this, flowThreadPortionRect(), flowThreadPortionOverflowRect(), request, result,
            locationInContainer, LayoutPoint(accumulatedOffset.x() + borderLeft() + paddingLeft(), accumulatedOffset.y() + borderTop() + paddingTop())))
            return true;
    }

    return false;
}

void RenderSVGRoot::calcPrefWidths()
{
    ASSERT(prefWidthsDirty());

    int paddingAndBorders = paddingLeft() + paddingRight() + borderLeft() + borderRight();
    int width = calcReplacedWidth(false) + paddingAndBorders;

    if (style()->maxWidth().isFixed() && style()->maxWidth().value() != undefinedLength)
        width = min(width, style()->maxWidth().value() + (style()->boxSizing() == CONTENT_BOX ? paddingAndBorders : 0));

    if (style()->width().isPercent() || (style()->width().isAuto() && style()->height().isPercent())) {
        m_minPrefWidth = 0;
        m_maxPrefWidth = width;
    } else
        m_minPrefWidth = m_maxPrefWidth = width;

    setPrefWidthsDirty(false);
}

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());
    if (style()->outlineWidth())
        paintOutline(paintInfo, paintRect);

    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());
    }
}

void RenderWidget::paint(PaintInfo& paintInfo, int tx, int ty)
{
    if (!shouldPaint(paintInfo, tx, ty))
        return;

    tx += x();
    ty += y();

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

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

    if (!m_view || paintInfo.phase != PaintPhaseForeground || style()->visibility() != VISIBLE)
        return;

#if PLATFORM(MAC)
    if (style()->highlight() != nullAtom && !paintInfo.context->paintingDisabled())
        paintCustomHighlight(tx - x(), ty - y(), style()->highlight(), true);
#endif

    if (m_widget) {
        // Move the widget if necessary.  We normally move and resize widgets during layout, but sometimes
        // widgets can move without layout occurring (most notably when you scroll a document that
        // contains fixed positioned elements).
        m_widget->move(tx + borderLeft() + paddingLeft(), ty + borderTop() + paddingTop());

        // Tell the widget to paint now.  This is the only time the widget is allowed
        // to paint itself.  That way it will composite properly with z-indexed layers.
        m_widget->paint(paintInfo.context, paintInfo.rect);
    }

    // Paint a partially transparent wash over selected widgets.
    if (isSelected() && !document()->printing()) {
        // FIXME: selectionRect() is in absolute, not painting coordinates.
        paintInfo.context->fillRect(selectionRect(), selectionBackgroundColor());
    }
}

bool RenderPart::nodeAtPoint(const HitTestRequest& request, HitTestResult& result, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction action)
{
    if (!widget() || !widget()->isFrameView() || !request.allowsChildFrameContent())
        return RenderWidget::nodeAtPoint(request, result, locationInContainer, accumulatedOffset, action);

    FrameView* childFrameView = toFrameView(widget());
    RenderView* childRoot = childFrameView->renderView();

    if (childRoot) {
        LayoutPoint adjustedLocation = accumulatedOffset + location();
        LayoutPoint contentOffset = LayoutPoint(borderLeft() + paddingLeft(), borderTop() + paddingTop()) - childFrameView->scrollOffset();
        HitTestLocation newHitTestLocation(locationInContainer, -adjustedLocation - contentOffset);
        HitTestRequest newHitTestRequest(request.type() | HitTestRequest::ChildFrameHitTest);
        HitTestResult childFrameResult(newHitTestLocation);

        bool isInsideChildFrame = childRoot->hitTest(newHitTestRequest, newHitTestLocation, childFrameResult);

        if (newHitTestLocation.isRectBasedTest())
            result.append(childFrameResult);
        else if (isInsideChildFrame)
            result = childFrameResult;

        if (isInsideChildFrame)
            return true;

        if (request.allowsFrameScrollbars()) {
            // ScrollView scrollbars are not the same as RenderLayer scrollbars tested by RenderLayer::hitTestOverflowControls,
            // so we need to test ScrollView scrollbars separately here.
            // FIXME: Consider if this test could be done unconditionally.
            Scrollbar* frameScrollbar = childFrameView->scrollbarAtPoint(newHitTestLocation.roundedPoint());
            if (frameScrollbar)
                result.setScrollbar(frameScrollbar);
        }
    }

    return RenderWidget::nodeAtPoint(request, result, locationInContainer, accumulatedOffset, action);
}

// Hit Testing
bool RenderRegion::nodeAtPoint(const HitTestRequest& request, HitTestResult& result, const LayoutPoint& pointInContainer, const LayoutPoint& accumulatedOffset, HitTestAction action)
{
    if (!isValid())
        return false;

    LayoutPoint adjustedLocation = accumulatedOffset + location();

    // Check our bounds next. For this purpose always assume that we can only be hit in the
    // foreground phase (which is true for replaced elements like images).
    LayoutRect boundsRect(adjustedLocation, size());
    if (visibleToHitTesting() && action == HitTestForeground && boundsRect.intersects(result.rectForPoint(pointInContainer))) {
        // Check the contents of the RenderFlowThread.
        if (m_flowThread && m_flowThread->hitTestRegion(this, request, result, pointInContainer, LayoutPoint(adjustedLocation.x() + borderLeft() + paddingLeft(), adjustedLocation.y() + borderTop() + paddingTop())))
            return true;
        updateHitTestResult(result, pointInContainer - toLayoutSize(adjustedLocation));
        if (!result.addNodeToRectBasedTestResult(node(), pointInContainer, boundsRect))
            return true;
    }

    return false;
}

void RenderRegion::paintReplaced(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
{
    // Delegate painting of content in region to RenderFlowThread.
    if (!m_flowThread || !isValid())
        return;
    m_flowThread->paintIntoRegion(paintInfo, this, LayoutPoint(paintOffset.x() + borderLeft() + paddingLeft(), paintOffset.y() + borderTop() + paddingTop()));
}

void RenderSVGContainer::paint(PaintInfo& paintInfo, int parentX, int parentY)
{
    if (paintInfo.context->paintingDisabled())
        return;

    // This should only exist for <svg> renderers
    if (hasBoxDecorations() && (paintInfo.phase == PaintPhaseForeground || paintInfo.phase == PaintPhaseSelection)) 
        paintBoxDecorations(paintInfo, m_x + parentX, m_y + parentY);

    if ((paintInfo.phase == PaintPhaseOutline || paintInfo.phase == PaintPhaseSelfOutline) && style()->outlineWidth() && style()->visibility() == VISIBLE)
        paintOutline(paintInfo.context, parentX, parentY, width(), height(), style());
    
    if (paintInfo.phase != PaintPhaseForeground || !drawsContents())
        return;

    const SVGRenderStyle* svgStyle = style()->svgStyle();
    AtomicString filterId(SVGURIReference::getTarget(svgStyle->filter()));

#if ENABLE(SVG_EXPERIMENTAL_FEATURES) 
    SVGResourceFilter* filter = getFilterById(document(), filterId);
#endif

    if (!firstChild()
#if ENABLE(SVG_EXPERIMENTAL_FEATURES) 
        && !filter
#endif
        )
        return; // Spec: groups w/o children still may render filter content.
    
    paintInfo.context->save();

    if (!parent()->isSVGContainer()) {
        // Translate from parent offsets (html renderers) to a relative transform (svg renderers)
        IntPoint origin;
        origin.move(parentX, parentY);
        origin.move(m_x, m_y);
        origin.move(borderLeft(), borderTop());
        origin.move(paddingLeft(), paddingTop());
        if (origin.x() || origin.y()) {
            paintInfo.context->concatCTM(AffineTransform().translate(origin.x(), origin.y()));
            paintInfo.rect.move(-origin.x(), -origin.y());
        }
        parentX = parentY = 0;
        SVGSVGElement* svg = static_cast<SVGSVGElement*>(element());
        paintInfo.context->concatCTM(AffineTransform().scale(svg->currentScale()));
    } else {
        // Only the root <svg> element should need any translations using the HTML/CSS system
        // parentX, parentY are also non-zero for first-level kids of these
        // CSS-transformed <svg> root-elements (due to RenderBox::paint) for any other element
        // they should be 0.   m_x, m_y should always be 0 for non-root svg containers
        ASSERT(m_x == 0);
        ASSERT(m_y == 0);
    }

    if (!viewport().isEmpty()) {
        if (style()->overflowX() != OVISIBLE)
            paintInfo.context->clip(enclosingIntRect(viewport())); // FIXME: Eventually we'll want float-precision clipping

        paintInfo.context->concatCTM(AffineTransform().translate(viewport().x(), viewport().y()));
    }
    if (!localTransform().isIdentity())
        paintInfo.context->concatCTM(localTransform());
    if (!parent()->isSVGContainer()) {
        SVGSVGElement* svg = static_cast<SVGSVGElement*>(element());
        paintInfo.context->concatCTM(AffineTransform().translate(svg->currentTranslate().x(), svg->currentTranslate().y()));
    }

    FloatRect strokeBBox = relativeBBox(true);

    SVGElement* svgElement = static_cast<SVGElement*>(element());
    ASSERT(svgElement && svgElement->document() && svgElement->isStyled());

    SVGStyledElement* styledElement = static_cast<SVGStyledElement*>(svgElement);
 
    AtomicString clipperId(SVGURIReference::getTarget(svgStyle->clipPath()));
    AtomicString maskerId(SVGURIReference::getTarget(svgStyle->maskElement()));

    SVGResourceClipper* clipper = getClipperById(document(), clipperId);
    SVGResourceMasker* masker = getMaskerById(document(), maskerId);

    if (clipper) {
        clipper->addClient(styledElement);
        clipper->applyClip(paintInfo.context, strokeBBox);
    } else if (!clipperId.isEmpty())
        svgElement->document()->accessSVGExtensions()->addPendingResource(clipperId, styledElement);

    if (masker) {
        masker->addClient(styledElement);
        masker->applyMask(paintInfo.context, strokeBBox);
    } else if (!maskerId.isEmpty())
        svgElement->document()->accessSVGExtensions()->addPendingResource(maskerId, styledElement);

    float opacity = style()->opacity();
    if (opacity < 1.0f) {
        paintInfo.context->clip(enclosingIntRect(strokeBBox));
        paintInfo.context->beginTransparencyLayer(opacity);
    }

#if ENABLE(SVG_EXPERIMENTAL_FEATURES)
    if (filter)
//.........这里部分代码省略.........

void RenderMedia::layout()
{
    StackStats::LayoutCheckPoint layoutCheckPoint;
    LayoutSize oldSize = contentBoxRect().size();

    RenderImage::layout();

    RenderBox* controlsRenderer = toRenderBox(m_children.firstChild());
    if (!controlsRenderer)
        return;

    bool controlsNeedLayout = controlsRenderer->needsLayout();
    // If the region chain has changed we also need to relayout the controls to update the region box info.
    // FIXME: We can do better once we compute region box info for RenderReplaced, not only for RenderBlock.
    const RenderFlowThread* flowThread = flowThreadContainingBlock();
    if (flowThread && !controlsNeedLayout) {
        if (flowThread->pageLogicalSizeChanged())
            controlsNeedLayout = true;
    }

    LayoutSize newSize = contentBoxRect().size();
    if (newSize == oldSize && !controlsNeedLayout)
        return;

    // When calling layout() on a child node, a parent must either push a LayoutStateMaintainter, or 
    // instantiate LayoutStateDisabler. Since using a LayoutStateMaintainer is slightly more efficient,
    // and this method will be called many times per second during playback, use a LayoutStateMaintainer:
    LayoutStateMaintainer statePusher(view(), this, locationOffset(), hasTransform() || hasReflection() || style()->isFlippedBlocksWritingMode());

    controlsRenderer->setLocation(LayoutPoint(borderLeft(), borderTop()) + LayoutSize(paddingLeft(), paddingTop()));
    controlsRenderer->style()->setHeight(Length(newSize.height(), Fixed));
    controlsRenderer->style()->setWidth(Length(newSize.width(), Fixed));
    controlsRenderer->setNeedsLayout(true, MarkOnlyThis);
    controlsRenderer->layout();
    setChildNeedsLayout(false);

    statePusher.pop();
}

// Hit Testing
bool RenderRegion::nodeAtPoint(const HitTestRequest& request, HitTestResult& result, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction action)
{
    if (!isValid())
        return false;

    LayoutPoint adjustedLocation = accumulatedOffset + location();

    // Check our bounds next. For this purpose always assume that we can only be hit in the
    // foreground phase (which is true for replaced elements like images).
    // FIXME: Once we support overflow, we need to intersect with that and not with the bounds rect.
    LayoutRect boundsRect = borderBoxRectInRegion(locationInContainer.region());
    boundsRect.moveBy(adjustedLocation);
    if (visibleToHitTestRequest(request) && action == HitTestForeground && locationInContainer.intersects(boundsRect)) {
        // Check the contents of the RenderFlowThread.
        if (m_flowThread->hitTestFlowThreadPortionInRegion(this, flowThreadPortionRect(), flowThreadPortionOverflowRect(), request, result, locationInContainer, LayoutPoint(adjustedLocation.x() + borderLeft() + paddingLeft(), adjustedLocation.y() + borderTop() + paddingTop())))
            return true;
        updateHitTestResult(result, locationInContainer.point() - toLayoutSize(adjustedLocation));
        if (!result.addNodeToRectBasedTestResult(generatingNode(), request, locationInContainer, boundsRect))
            return true;
    }

    return false;
}

void RenderMultiColumnSet::paintColumnRules(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
{
    if (paintInfo.context->paintingDisabled())
        return;

    RenderStyle* blockStyle = toRenderMultiColumnBlock(parent())->style();
    const Color& ruleColor = blockStyle->visitedDependentColor(CSSPropertyWebkitColumnRuleColor);
    bool ruleTransparent = blockStyle->columnRuleIsTransparent();
    EBorderStyle ruleStyle = blockStyle->columnRuleStyle();
    LayoutUnit ruleThickness = blockStyle->columnRuleWidth();
    LayoutUnit colGap = columnGap();
    bool renderRule = ruleStyle > BHIDDEN && !ruleTransparent && ruleThickness <= colGap;
    if (!renderRule)
        return;

    unsigned colCount = columnCount();
    if (colCount <= 1)
        return;

    bool antialias = shouldAntialiasLines(paintInfo.context);

    bool leftToRight = style()->isLeftToRightDirection();
    LayoutUnit currLogicalLeftOffset = leftToRight ? ZERO_LAYOUT_UNIT : contentLogicalWidth();
    LayoutUnit ruleAdd = borderAndPaddingLogicalLeft();
    LayoutUnit ruleLogicalLeft = leftToRight ? ZERO_LAYOUT_UNIT : contentLogicalWidth();
    LayoutUnit inlineDirectionSize = computedColumnWidth();
    BoxSide boxSide = isHorizontalWritingMode()
        ? leftToRight ? BSLeft : BSRight
        : leftToRight ? BSTop : BSBottom;

    for (unsigned i = 0; i < colCount; i++) {
        // Move to the next position.
        if (leftToRight) {
            ruleLogicalLeft += inlineDirectionSize + colGap / 2;
            currLogicalLeftOffset += inlineDirectionSize + colGap;
        } else {
            ruleLogicalLeft -= (inlineDirectionSize + colGap / 2);
            currLogicalLeftOffset -= (inlineDirectionSize + colGap);
        }
       
        // Now paint the column rule.
        if (i < colCount - 1) {
            LayoutUnit ruleLeft = isHorizontalWritingMode() ? paintOffset.x() + ruleLogicalLeft - ruleThickness / 2 + ruleAdd : paintOffset.x() + borderLeft() + paddingLeft();
            LayoutUnit ruleRight = isHorizontalWritingMode() ? ruleLeft + ruleThickness : ruleLeft + contentWidth();
            LayoutUnit ruleTop = isHorizontalWritingMode() ? paintOffset.y() + borderTop() + paddingTop() : paintOffset.y() + ruleLogicalLeft - ruleThickness / 2 + ruleAdd;
            LayoutUnit ruleBottom = isHorizontalWritingMode() ? ruleTop + contentHeight() : ruleTop + ruleThickness;
            IntRect pixelSnappedRuleRect = pixelSnappedIntRectFromEdges(ruleLeft, ruleTop, ruleRight, ruleBottom);
            drawLineForBoxSide(paintInfo.context, pixelSnappedRuleRect.x(), pixelSnappedRuleRect.y(), pixelSnappedRuleRect.maxX(), pixelSnappedRuleRect.maxY(), boxSide, ruleColor, ruleStyle, 0, 0, antialias);
        }
        
        ruleLogicalLeft = currLogicalLeftOffset;
    }
}

LayoutRect RenderBoxModelObject::localCaretRectForEmptyElement(LayoutUnit width, LayoutUnit textIndentOffset)
{
    ASSERT(!slowFirstChild());

    // FIXME: This does not take into account either :first-line or :first-letter
    // However, as soon as some content is entered, the line boxes will be
    // constructed and this kludge is not called any more. So only the caret size
    // of an empty :first-line'd block is wrong. I think we can live with that.
    RenderStyle* currentStyle = firstLineStyle();

    enum CaretAlignment { alignLeft, alignRight, alignCenter };

    CaretAlignment alignment = alignLeft;

    switch (currentStyle->textAlign()) {
    case LEFT:
    case WEBKIT_LEFT:
        break;
    case CENTER:
    case WEBKIT_CENTER:
        alignment = alignCenter;
        break;
    case RIGHT:
    case WEBKIT_RIGHT:
        alignment = alignRight;
        break;
    case JUSTIFY:
    case TASTART:
        if (!currentStyle->isLeftToRightDirection())
            alignment = alignRight;
        break;
    case TAEND:
        if (currentStyle->isLeftToRightDirection())
            alignment = alignRight;
        break;
    }

    LayoutUnit x = borderLeft() + paddingLeft();
    LayoutUnit maxX = width - borderRight() - paddingRight();

    switch (alignment) {
    case alignLeft:
        if (currentStyle->isLeftToRightDirection())
            x += textIndentOffset;
        break;
    case alignCenter:
        x = (x + maxX) / 2;
        if (currentStyle->isLeftToRightDirection())
            x += textIndentOffset / 2;
        else
            x -= textIndentOffset / 2;
        break;
    case alignRight:
        x = maxX - caretWidth;
        if (!currentStyle->isLeftToRightDirection())
            x -= textIndentOffset;
        break;
    }
    x = std::min(x, std::max<LayoutUnit>(maxX - caretWidth, 0));

    LayoutUnit height = style()->fontMetrics().height();
    LayoutUnit verticalSpace = lineHeight(true, currentStyle->isHorizontalWritingMode() ? HorizontalLine : VerticalLine,  PositionOfInteriorLineBoxes) - height;
    LayoutUnit y = paddingTop() + borderTop() + (verticalSpace / 2);
    return currentStyle->isHorizontalWritingMode() ? LayoutRect(x, y, caretWidth, height) : LayoutRect(y, x, height, caretWidth);
}

IntSize RenderSVGRoot::borderOriginToContentBox() const
{
    return IntSize(borderLeft() + paddingLeft(), borderTop() + paddingTop());
}

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());
    }
}

void RenderRegion::paintReplaced(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
{
    // Delegate painting of content in region to RenderFlowThread.
    if (!m_flowThread || !isValid())
        return;

    if (Frame* frame = this->frame()) {
        if (Page* page = frame->page())
            page->addRelevantRepaintedObject(this, paintInfo.rect);
    }

    setRegionBoxesRegionStyle();
    m_flowThread->paintIntoRegion(paintInfo, this, LayoutPoint(paintOffset.x() + borderLeft() + paddingLeft(), paintOffset.y() + borderTop() + paddingTop()));
    restoreRegionBoxesOriginalStyle();
}