root/Source/core/rendering/InlineFlowBox.cpp

DEFINITIONS

1. getFlowSpacingLogicalWidth
2. roundedFrameRect
3. setHasTextDescendantsOnAncestors
4. addToLine
5. removeChild
6. deleteLine
7. removeLineBoxFromRenderObject
8. extractLine
9. extractLineBoxFromRenderObject
10. attachLine
11. attachLineBoxToRenderObject
12. adjustPosition
13. rendererLineBoxes
14. isLastChildForRenderer
15. isAnsectorAndWithinBlock
16. determineSpacingForFlowBoxes
17. placeBoxesInInlineDirection
18. placeBoxRangeInInlineDirection
19. requiresIdeographicBaseline
20. adjustMaxAscentAndDescent
21. computeLogicalBoxHeights
22. placeBoxesInBlockDirection
23. computeMaxLogicalTop
24. flipLinesInBlockDirection
25. addBoxShadowVisualOverflow
26. addBorderOutsetVisualOverflow
27. addOutlineVisualOverflow
28. addTextBoxVisualOverflow
29. addReplacedChildOverflow
30. computeOverflow
31. setLayoutOverflow
32. setVisualOverflow
33. setOverflowFromLogicalRects
34. nodeAtPoint
35. paint
36. paintFillLayers
37. boxShadowCanBeAppliedToBackground
38. paintFillLayer
39. paintBoxShadow
40. constrainToLineTopAndBottomIfNeeded
41. clipRectForNinePieceImageStrip
42. paintBoxDecorations
43. paintMask
44. firstLeafChild
45. lastLeafChild
46. selectionState
47. canAccommodateEllipsis
48. placeEllipsisBox
49. clearTruncation
50. computeOverAnnotationAdjustment
51. computeUnderAnnotationAdjustment
52. collectLeafBoxesInLogicalOrder
53. boxName
54. showLineTreeAndMark
55. checkConsistency

/*
 * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#include "config.h"
#include "core/rendering/InlineFlowBox.h"

#include "CSSPropertyNames.h"
#include "core/dom/Document.h"
#include "core/rendering/HitTestResult.h"
#include "core/rendering/InlineTextBox.h"
#include "core/rendering/RenderBlock.h"
#include "core/rendering/RenderInline.h"
#include "core/rendering/RenderLayer.h"
#include "core/rendering/RenderListMarker.h"
#include "core/rendering/RenderRubyBase.h"
#include "core/rendering/RenderRubyRun.h"
#include "core/rendering/RenderRubyText.h"
#include "core/rendering/RenderView.h"
#include "core/rendering/RootInlineBox.h"
#include "platform/fonts/Font.h"
#include "platform/graphics/GraphicsContextStateSaver.h"

#include <math.h>

using namespace std;

namespace WebCore {

struct SameSizeAsInlineFlowBox : public InlineBox {
    void* pointers[5];
    uint32_t bitfields : 23;
};

COMPILE_ASSERT(sizeof(InlineFlowBox) == sizeof(SameSizeAsInlineFlowBox), InlineFlowBox_should_stay_small);

#ifndef NDEBUG

InlineFlowBox::~InlineFlowBox()
{
    if (!m_hasBadChildList)
        for (InlineBox* child = firstChild(); child; child = child->nextOnLine())
            child->setHasBadParent();
}

#endif

LayoutUnit InlineFlowBox::getFlowSpacingLogicalWidth()
{
    LayoutUnit totWidth = marginBorderPaddingLogicalLeft() + marginBorderPaddingLogicalRight();
    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
        if (curr->isInlineFlowBox())
            totWidth += toInlineFlowBox(curr)->getFlowSpacingLogicalWidth();
    }
    return totWidth;
}

IntRect InlineFlowBox::roundedFrameRect() const
{
    // Begin by snapping the x and y coordinates to the nearest pixel.
    int snappedX = lroundf(x());
    int snappedY = lroundf(y());

    int snappedMaxX = lroundf(x() + width());
    int snappedMaxY = lroundf(y() + height());

    return IntRect(snappedX, snappedY, snappedMaxX - snappedX, snappedMaxY - snappedY);
}

static void setHasTextDescendantsOnAncestors(InlineFlowBox* box)
{
    while (box && !box->hasTextDescendants()) {
        box->setHasTextDescendants();
        box = box->parent();
    }
}

void InlineFlowBox::addToLine(InlineBox* child)
{
    ASSERT(!child->parent());
    ASSERT(!child->nextOnLine());
    ASSERT(!child->prevOnLine());
    checkConsistency();

    child->setParent(this);
    if (!m_firstChild) {
        m_firstChild = child;
        m_lastChild = child;
    } else {
        m_lastChild->setNextOnLine(child);
        child->setPrevOnLine(m_lastChild);
        m_lastChild = child;
    }
    child->setFirstLineStyleBit(isFirstLineStyle());
    child->setIsHorizontal(isHorizontal());
    if (child->isText()) {
        if (child->renderer().parent() == renderer())
            m_hasTextChildren = true;
        setHasTextDescendantsOnAncestors(this);
    } else if (child->isInlineFlowBox()) {
        if (toInlineFlowBox(child)->hasTextDescendants())
            setHasTextDescendantsOnAncestors(this);
    }

    if (descendantsHaveSameLineHeightAndBaseline() && !child->renderer().isOutOfFlowPositioned()) {
        RenderStyle* parentStyle = renderer().style(isFirstLineStyle());
        RenderStyle* childStyle = child->renderer().style(isFirstLineStyle());
        bool shouldClearDescendantsHaveSameLineHeightAndBaseline = false;
        if (child->renderer().isReplaced())
            shouldClearDescendantsHaveSameLineHeightAndBaseline = true;
        else if (child->isText()) {
            if (child->renderer().isBR() || child->renderer().parent() != renderer()) {
                if (!parentStyle->font().fontMetrics().hasIdenticalAscentDescentAndLineGap(childStyle->font().fontMetrics())
                    || parentStyle->lineHeight() != childStyle->lineHeight()
                    || (parentStyle->verticalAlign() != BASELINE && !isRootInlineBox()) || childStyle->verticalAlign() != BASELINE)
                    shouldClearDescendantsHaveSameLineHeightAndBaseline = true;
            }
            if (childStyle->hasTextCombine() || childStyle->textEmphasisMark() != TextEmphasisMarkNone)
                shouldClearDescendantsHaveSameLineHeightAndBaseline = true;
        } else {
            if (child->renderer().isBR()) {
                // FIXME: This is dumb. We only turn off because current layout test results expect the <br> to be 0-height on the baseline.
                // Other than making a zillion tests have to regenerate results, there's no reason to ditch the optimization here.
                shouldClearDescendantsHaveSameLineHeightAndBaseline = true;
            } else {
                ASSERT(isInlineFlowBox());
                InlineFlowBox* childFlowBox = toInlineFlowBox(child);
                // Check the child's bit, and then also check for differences in font, line-height, vertical-align
                if (!childFlowBox->descendantsHaveSameLineHeightAndBaseline()
                    || !parentStyle->font().fontMetrics().hasIdenticalAscentDescentAndLineGap(childStyle->font().fontMetrics())
                    || parentStyle->lineHeight() != childStyle->lineHeight()
                    || (parentStyle->verticalAlign() != BASELINE && !isRootInlineBox()) || childStyle->verticalAlign() != BASELINE
                    || childStyle->hasBorder() || childStyle->hasPadding() || childStyle->hasTextCombine())
                    shouldClearDescendantsHaveSameLineHeightAndBaseline = true;
            }
        }

        if (shouldClearDescendantsHaveSameLineHeightAndBaseline)
            clearDescendantsHaveSameLineHeightAndBaseline();
    }

    if (!child->renderer().isOutOfFlowPositioned()) {
        if (child->isText()) {
            RenderStyle* childStyle = child->renderer().style(isFirstLineStyle());
            if (childStyle->letterSpacing() < 0 || childStyle->textShadow() || childStyle->textEmphasisMark() != TextEmphasisMarkNone || childStyle->textStrokeWidth())
                child->clearKnownToHaveNoOverflow();
        } else if (child->renderer().isReplaced()) {
            RenderBox& box = toRenderBox(child->renderer());
            if (box.hasRenderOverflow() || box.hasSelfPaintingLayer())
                child->clearKnownToHaveNoOverflow();
        } else if (!child->renderer().isBR() && (child->renderer().style(isFirstLineStyle())->boxShadow() || child->boxModelObject()->hasSelfPaintingLayer()
            || (child->renderer().isListMarker() && !toRenderListMarker(child->renderer()).isInside())
            || child->renderer().style(isFirstLineStyle())->hasBorderImageOutsets()
            || child->renderer().style(isFirstLineStyle())->hasOutline())) {
            child->clearKnownToHaveNoOverflow();
        }

        if (knownToHaveNoOverflow() && child->isInlineFlowBox() && !toInlineFlowBox(child)->knownToHaveNoOverflow())
            clearKnownToHaveNoOverflow();
    }

    checkConsistency();
}

void InlineFlowBox::removeChild(InlineBox* child)
{
    checkConsistency();

    if (!isDirty())
        dirtyLineBoxes();

    root().childRemoved(child);

    if (child == m_firstChild)
        m_firstChild = child->nextOnLine();
    if (child == m_lastChild)
        m_lastChild = child->prevOnLine();
    if (child->nextOnLine())
        child->nextOnLine()->setPrevOnLine(child->prevOnLine());
    if (child->prevOnLine())
        child->prevOnLine()->setNextOnLine(child->nextOnLine());

    child->setParent(0);

    checkConsistency();
}

void InlineFlowBox::deleteLine()
{
    InlineBox* child = firstChild();
    InlineBox* next = 0;
    while (child) {
        ASSERT(this == child->parent());
        next = child->nextOnLine();
#ifndef NDEBUG
        child->setParent(0);
#endif
        child->deleteLine();
        child = next;
    }
#ifndef NDEBUG
    m_firstChild = 0;
    m_lastChild = 0;
#endif

    removeLineBoxFromRenderObject();
    destroy();
}

void InlineFlowBox::removeLineBoxFromRenderObject()
{
    rendererLineBoxes()->removeLineBox(this);
}

void InlineFlowBox::extractLine()
{
    if (!extracted())
        extractLineBoxFromRenderObject();
    for (InlineBox* child = firstChild(); child; child = child->nextOnLine())
        child->extractLine();
}

void InlineFlowBox::extractLineBoxFromRenderObject()
{
    rendererLineBoxes()->extractLineBox(this);
}

void InlineFlowBox::attachLine()
{
    if (extracted())
        attachLineBoxToRenderObject();
    for (InlineBox* child = firstChild(); child; child = child->nextOnLine())
        child->attachLine();
}

void InlineFlowBox::attachLineBoxToRenderObject()
{
    rendererLineBoxes()->attachLineBox(this);
}

void InlineFlowBox::adjustPosition(float dx, float dy)
{
    InlineBox::adjustPosition(dx, dy);
    for (InlineBox* child = firstChild(); child; child = child->nextOnLine())
        child->adjustPosition(dx, dy);
    if (m_overflow)
        m_overflow->move(dx, dy); // FIXME: Rounding error here since overflow was pixel snapped, but nobody other than list markers passes non-integral values here.
}

RenderLineBoxList* InlineFlowBox::rendererLineBoxes() const
{
    return toRenderInline(renderer()).lineBoxes();
}

static inline bool isLastChildForRenderer(RenderObject* ancestor, RenderObject* child)
{
    if (!child)
        return false;

    if (child == ancestor)
        return true;

    RenderObject* curr = child;
    RenderObject* parent = curr->parent();
    while (parent && (!parent->isRenderBlock() || parent->isInline())) {
        if (parent->lastChild() != curr)
            return false;
        if (parent == ancestor)
            return true;

        curr = parent;
        parent = curr->parent();
    }

    return true;
}

static bool isAnsectorAndWithinBlock(RenderObject* ancestor, RenderObject* child)
{
    RenderObject* object = child;
    while (object && (!object->isRenderBlock() || object->isInline())) {
        if (object == ancestor)
            return true;
        object = object->parent();
    }
    return false;
}

void InlineFlowBox::determineSpacingForFlowBoxes(bool lastLine, bool isLogicallyLastRunWrapped, RenderObject* logicallyLastRunRenderer)
{
    // All boxes start off open.  They will not apply any margins/border/padding on
    // any side.
    bool includeLeftEdge = false;
    bool includeRightEdge = false;

    // The root inline box never has borders/margins/padding.
    if (parent()) {
        bool ltr = renderer().style()->isLeftToRightDirection();

        // Check to see if all initial lines are unconstructed.  If so, then
        // we know the inline began on this line (unless we are a continuation).
        RenderLineBoxList* lineBoxList = rendererLineBoxes();
        if (!lineBoxList->firstLineBox()->isConstructed() && !renderer().isInlineElementContinuation()) {
            if (renderer().style()->boxDecorationBreak() == DCLONE)
                includeLeftEdge = includeRightEdge = true;
            else if (ltr && lineBoxList->firstLineBox() == this)
                includeLeftEdge = true;
            else if (!ltr && lineBoxList->lastLineBox() == this)
                includeRightEdge = true;
        }

        if (!lineBoxList->lastLineBox()->isConstructed()) {
            RenderInline& inlineFlow = toRenderInline(renderer());
            bool isLastObjectOnLine = !isAnsectorAndWithinBlock(&renderer(), logicallyLastRunRenderer) || (isLastChildForRenderer(&renderer(), logicallyLastRunRenderer) && !isLogicallyLastRunWrapped);

            // We include the border under these conditions:
            // (1) The next line was not created, or it is constructed. We check the previous line for rtl.
            // (2) The logicallyLastRun is not a descendant of this renderer.
            // (3) The logicallyLastRun is a descendant of this renderer, but it is the last child of this renderer and it does not wrap to the next line.
            // (4) The decoration break is set to clone therefore there will be borders on every sides.
            if (renderer().style()->boxDecorationBreak() == DCLONE)
                includeLeftEdge = includeRightEdge = true;
            else if (ltr) {
                if (!nextLineBox()
                    && ((lastLine || isLastObjectOnLine) && !inlineFlow.continuation()))
                    includeRightEdge = true;
            } else {
                if ((!prevLineBox() || prevLineBox()->isConstructed())
                    && ((lastLine || isLastObjectOnLine) && !inlineFlow.continuation()))
                    includeLeftEdge = true;
            }
        }
    }

    setEdges(includeLeftEdge, includeRightEdge);

    // Recur into our children.
    for (InlineBox* currChild = firstChild(); currChild; currChild = currChild->nextOnLine()) {
        if (currChild->isInlineFlowBox()) {
            InlineFlowBox* currFlow = toInlineFlowBox(currChild);
            currFlow->determineSpacingForFlowBoxes(lastLine, isLogicallyLastRunWrapped, logicallyLastRunRenderer);
        }
    }
}

float InlineFlowBox::placeBoxesInInlineDirection(float logicalLeft, bool& needsWordSpacing, GlyphOverflowAndFallbackFontsMap& textBoxDataMap)
{
    // Set our x position.
    beginPlacingBoxRangesInInlineDirection(logicalLeft);

    float startLogicalLeft = logicalLeft;
    logicalLeft += borderLogicalLeft() + paddingLogicalLeft();

    float minLogicalLeft = startLogicalLeft;
    float maxLogicalRight = logicalLeft;

    placeBoxRangeInInlineDirection(firstChild(), 0, logicalLeft, minLogicalLeft, maxLogicalRight, needsWordSpacing, textBoxDataMap);

    logicalLeft += borderLogicalRight() + paddingLogicalRight();
    endPlacingBoxRangesInInlineDirection(startLogicalLeft, logicalLeft, minLogicalLeft, maxLogicalRight);
    return logicalLeft;
}

float InlineFlowBox::placeBoxRangeInInlineDirection(InlineBox* firstChild, InlineBox* lastChild, float& logicalLeft, float& minLogicalLeft, float& maxLogicalRight, bool& needsWordSpacing, GlyphOverflowAndFallbackFontsMap& textBoxDataMap)
{
    for (InlineBox* curr = firstChild; curr && curr != lastChild; curr = curr->nextOnLine()) {
        if (curr->renderer().isText()) {
            InlineTextBox* text = toInlineTextBox(curr);
            RenderText& rt = toRenderText(text->renderer());
            if (rt.textLength()) {
                if (needsWordSpacing && isSpaceOrNewline(rt.characterAt(text->start())))
                    logicalLeft += rt.style(isFirstLineStyle())->font().fontDescription().wordSpacing();
                needsWordSpacing = !isSpaceOrNewline(rt.characterAt(text->end()));
            }
            text->setLogicalLeft(logicalLeft);
            if (knownToHaveNoOverflow())
                minLogicalLeft = min(logicalLeft, minLogicalLeft);
            logicalLeft += text->logicalWidth();
            if (knownToHaveNoOverflow())
                maxLogicalRight = max(logicalLeft, maxLogicalRight);
        } else {
            if (curr->renderer().isOutOfFlowPositioned()) {
                if (curr->renderer().parent()->style()->isLeftToRightDirection()) {
                    curr->setLogicalLeft(logicalLeft);
                } else {
                    // Our offset that we cache needs to be from the edge of the right border box and
                    // not the left border box.  We have to subtract |x| from the width of the block
                    // (which can be obtained from the root line box).
                    curr->setLogicalLeft(root().block().logicalWidth() - logicalLeft);
                }
                continue; // The positioned object has no effect on the width.
            }
            if (curr->renderer().isRenderInline()) {
                InlineFlowBox* flow = toInlineFlowBox(curr);
                logicalLeft += flow->marginLogicalLeft();
                if (knownToHaveNoOverflow())
                    minLogicalLeft = min(logicalLeft, minLogicalLeft);
                logicalLeft = flow->placeBoxesInInlineDirection(logicalLeft, needsWordSpacing, textBoxDataMap);
                if (knownToHaveNoOverflow())
                    maxLogicalRight = max(logicalLeft, maxLogicalRight);
                logicalLeft += flow->marginLogicalRight();
            } else if (!curr->renderer().isListMarker() || toRenderListMarker(curr->renderer()).isInside()) {
                // The box can have a different writing-mode than the overall line, so this is a bit complicated.
                // Just get all the physical margin and overflow values by hand based off |isVertical|.
                LayoutUnit logicalLeftMargin = isHorizontal() ? curr->boxModelObject()->marginLeft() : curr->boxModelObject()->marginTop();
                LayoutUnit logicalRightMargin = isHorizontal() ? curr->boxModelObject()->marginRight() : curr->boxModelObject()->marginBottom();

                logicalLeft += logicalLeftMargin;
                curr->setLogicalLeft(logicalLeft);
                if (knownToHaveNoOverflow())
                    minLogicalLeft = min(logicalLeft, minLogicalLeft);
                logicalLeft += curr->logicalWidth();
                if (knownToHaveNoOverflow())
                    maxLogicalRight = max(logicalLeft, maxLogicalRight);
                logicalLeft += logicalRightMargin;
                // If we encounter any space after this inline block then ensure it is treated as the space between two words.
                needsWordSpacing = true;
            }
        }
    }
    return logicalLeft;
}

bool InlineFlowBox::requiresIdeographicBaseline(const GlyphOverflowAndFallbackFontsMap& textBoxDataMap) const
{
    if (isHorizontal())
        return false;

    if (renderer().style(isFirstLineStyle())->fontDescription().nonCJKGlyphOrientation() == NonCJKGlyphOrientationUpright
        || renderer().style(isFirstLineStyle())->font().primaryFont()->hasVerticalGlyphs())
        return true;

    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
        if (curr->renderer().isOutOfFlowPositioned())
            continue; // Positioned placeholders don't affect calculations.

        if (curr->isInlineFlowBox()) {
            if (toInlineFlowBox(curr)->requiresIdeographicBaseline(textBoxDataMap))
                return true;
        } else {
            if (curr->renderer().style(isFirstLineStyle())->font().primaryFont()->hasVerticalGlyphs())
                return true;

            const Vector<const SimpleFontData*>* usedFonts = 0;
            if (curr->isInlineTextBox()) {
                GlyphOverflowAndFallbackFontsMap::const_iterator it = textBoxDataMap.find(toInlineTextBox(curr));
                usedFonts = it == textBoxDataMap.end() ? 0 : &it->value.first;
            }

            if (usedFonts) {
                for (size_t i = 0; i < usedFonts->size(); ++i) {
                    if (usedFonts->at(i)->hasVerticalGlyphs())
                        return true;
                }
            }
        }
    }

    return false;
}

void InlineFlowBox::adjustMaxAscentAndDescent(int& maxAscent, int& maxDescent, int maxPositionTop, int maxPositionBottom)
{
    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
        // The computed lineheight needs to be extended for the
        // positioned elements
        if (curr->renderer().isOutOfFlowPositioned())
            continue; // Positioned placeholders don't affect calculations.
        if (curr->verticalAlign() == TOP || curr->verticalAlign() == BOTTOM) {
            int lineHeight = curr->lineHeight();
            if (curr->verticalAlign() == TOP) {
                if (maxAscent + maxDescent < lineHeight)
                    maxDescent = lineHeight - maxAscent;
            }
            else {
                if (maxAscent + maxDescent < lineHeight)
                    maxAscent = lineHeight - maxDescent;
            }

            if (maxAscent + maxDescent >= max(maxPositionTop, maxPositionBottom))
                break;
        }

        if (curr->isInlineFlowBox())
            toInlineFlowBox(curr)->adjustMaxAscentAndDescent(maxAscent, maxDescent, maxPositionTop, maxPositionBottom);
    }
}

void InlineFlowBox::computeLogicalBoxHeights(RootInlineBox* rootBox, LayoutUnit& maxPositionTop, LayoutUnit& maxPositionBottom,
                                             int& maxAscent, int& maxDescent, bool& setMaxAscent, bool& setMaxDescent,
                                             bool strictMode, GlyphOverflowAndFallbackFontsMap& textBoxDataMap,
                                             FontBaseline baselineType, VerticalPositionCache& verticalPositionCache)
{
    // The primary purpose of this function is to compute the maximal ascent and descent values for
    // a line. These values are computed based off the block's line-box-contain property, which indicates
    // what parts of descendant boxes have to fit within the line.
    //
    // The maxAscent value represents the distance of the highest point of any box (typically including line-height) from
    // the root box's baseline. The maxDescent value represents the distance of the lowest point of any box
    // (also typically including line-height) from the root box baseline. These values can be negative.
    //
    // A secondary purpose of this function is to store the offset of every box's baseline from the root box's
    // baseline. This information is cached in the logicalTop() of every box. We're effectively just using
    // the logicalTop() as scratch space.
    //
    // Because a box can be positioned such that it ends up fully above or fully below the
    // root line box, we only consider it to affect the maxAscent and maxDescent values if some
    // part of the box (EXCLUDING leading) is above (for ascent) or below (for descent) the root box's baseline.
    bool affectsAscent = false;
    bool affectsDescent = false;
    bool checkChildren = !descendantsHaveSameLineHeightAndBaseline();

    if (isRootInlineBox()) {
        // Examine our root box.
        int ascent = 0;
        int descent = 0;
        rootBox->ascentAndDescentForBox(rootBox, textBoxDataMap, ascent, descent, affectsAscent, affectsDescent);
        if (strictMode || hasTextChildren() || (!checkChildren && hasTextDescendants())) {
            if (maxAscent < ascent || !setMaxAscent) {
                maxAscent = ascent;
                setMaxAscent = true;
            }
            if (maxDescent < descent || !setMaxDescent) {
                maxDescent = descent;
                setMaxDescent = true;
            }
        }
    }

    if (!checkChildren)
        return;

    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
        if (curr->renderer().isOutOfFlowPositioned())
            continue; // Positioned placeholders don't affect calculations.

        InlineFlowBox* inlineFlowBox = curr->isInlineFlowBox() ? toInlineFlowBox(curr) : 0;

        bool affectsAscent = false;
        bool affectsDescent = false;

        // The verticalPositionForBox function returns the distance between the child box's baseline
        // and the root box's baseline.  The value is negative if the child box's baseline is above the
        // root box's baseline, and it is positive if the child box's baseline is below the root box's baseline.
        curr->setLogicalTop(rootBox->verticalPositionForBox(curr, verticalPositionCache).toFloat());

        int ascent = 0;
        int descent = 0;
        rootBox->ascentAndDescentForBox(curr, textBoxDataMap, ascent, descent, affectsAscent, affectsDescent);

        LayoutUnit boxHeight = ascent + descent;
        if (curr->verticalAlign() == TOP) {
            if (maxPositionTop < boxHeight)
                maxPositionTop = boxHeight;
        } else if (curr->verticalAlign() == BOTTOM) {
            if (maxPositionBottom < boxHeight)
                maxPositionBottom = boxHeight;
        } else if (!inlineFlowBox || strictMode || inlineFlowBox->hasTextChildren() || (inlineFlowBox->descendantsHaveSameLineHeightAndBaseline() && inlineFlowBox->hasTextDescendants())
                   || inlineFlowBox->boxModelObject()->hasInlineDirectionBordersOrPadding()) {
            // Note that these values can be negative.  Even though we only affect the maxAscent and maxDescent values
            // if our box (excluding line-height) was above (for ascent) or below (for descent) the root baseline, once you factor in line-height
            // the final box can end up being fully above or fully below the root box's baseline!  This is ok, but what it
            // means is that ascent and descent (including leading), can end up being negative.  The setMaxAscent and
            // setMaxDescent booleans are used to ensure that we're willing to initially set maxAscent/Descent to negative
            // values.
            ascent -= curr->logicalTop();
            descent += curr->logicalTop();
            if (affectsAscent && (maxAscent < ascent || !setMaxAscent)) {
                maxAscent = ascent;
                setMaxAscent = true;
            }

            if (affectsDescent && (maxDescent < descent || !setMaxDescent)) {
                maxDescent = descent;
                setMaxDescent = true;
            }
        }

        if (inlineFlowBox)
            inlineFlowBox->computeLogicalBoxHeights(rootBox, maxPositionTop, maxPositionBottom, maxAscent, maxDescent,
                                                    setMaxAscent, setMaxDescent, strictMode, textBoxDataMap,
                                                    baselineType, verticalPositionCache);
    }
}

void InlineFlowBox::placeBoxesInBlockDirection(LayoutUnit top, LayoutUnit maxHeight, int maxAscent, bool strictMode, LayoutUnit& lineTop, LayoutUnit& lineBottom, bool& setLineTop,
                                               LayoutUnit& lineTopIncludingMargins, LayoutUnit& lineBottomIncludingMargins, bool& hasAnnotationsBefore, bool& hasAnnotationsAfter, FontBaseline baselineType)
{
    bool isRootBox = isRootInlineBox();
    if (isRootBox) {
        const FontMetrics& fontMetrics = renderer().style(isFirstLineStyle())->fontMetrics();
        // RootInlineBoxes are always placed on at pixel boundaries in their logical y direction. Not doing
        // so results in incorrect rendering of text decorations, most notably underlines.
        setLogicalTop(roundToInt(top + maxAscent - fontMetrics.ascent(baselineType)));
    }

    LayoutUnit adjustmentForChildrenWithSameLineHeightAndBaseline = 0;
    if (descendantsHaveSameLineHeightAndBaseline()) {
        adjustmentForChildrenWithSameLineHeightAndBaseline = logicalTop();
        if (parent())
            adjustmentForChildrenWithSameLineHeightAndBaseline += (boxModelObject()->borderBefore() + boxModelObject()->paddingBefore());
    }

    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
        if (curr->renderer().isOutOfFlowPositioned())
            continue; // Positioned placeholders don't affect calculations.

        if (descendantsHaveSameLineHeightAndBaseline()) {
            curr->adjustBlockDirectionPosition(adjustmentForChildrenWithSameLineHeightAndBaseline.toFloat());
            continue;
        }

        InlineFlowBox* inlineFlowBox = curr->isInlineFlowBox() ? toInlineFlowBox(curr) : 0;
        bool childAffectsTopBottomPos = true;
        if (curr->verticalAlign() == TOP)
            curr->setLogicalTop(top.toFloat());
        else if (curr->verticalAlign() == BOTTOM)
            curr->setLogicalTop((top + maxHeight - curr->lineHeight()).toFloat());
        else {
            if (!strictMode && inlineFlowBox && !inlineFlowBox->hasTextChildren() && !curr->boxModelObject()->hasInlineDirectionBordersOrPadding()
                && !(inlineFlowBox->descendantsHaveSameLineHeightAndBaseline() && inlineFlowBox->hasTextDescendants()))
                childAffectsTopBottomPos = false;
            LayoutUnit posAdjust = maxAscent - curr->baselinePosition(baselineType);
            curr->setLogicalTop(curr->logicalTop() + top + posAdjust);
        }

        LayoutUnit newLogicalTop = curr->logicalTop();
        LayoutUnit newLogicalTopIncludingMargins = newLogicalTop;
        LayoutUnit boxHeight = curr->logicalHeight();
        LayoutUnit boxHeightIncludingMargins = boxHeight;

        if (curr->isText() || curr->isInlineFlowBox()) {
            const FontMetrics& fontMetrics = curr->renderer().style(isFirstLineStyle())->fontMetrics();
            newLogicalTop += curr->baselinePosition(baselineType) - fontMetrics.ascent(baselineType);
            if (curr->isInlineFlowBox()) {
                RenderBoxModelObject& boxObject = toRenderBoxModelObject(curr->renderer());
                newLogicalTop -= boxObject.style(isFirstLineStyle())->isHorizontalWritingMode() ? boxObject.borderTop() + boxObject.paddingTop() :
                    boxObject.borderRight() + boxObject.paddingRight();
            }
            newLogicalTopIncludingMargins = newLogicalTop;
        } else if (!curr->renderer().isBR()) {
            RenderBox& box = toRenderBox(curr->renderer());
            newLogicalTopIncludingMargins = newLogicalTop;
            LayoutUnit overSideMargin = curr->isHorizontal() ? box.marginTop() : box.marginRight();
            LayoutUnit underSideMargin = curr->isHorizontal() ? box.marginBottom() : box.marginLeft();
            newLogicalTop += overSideMargin;
            boxHeightIncludingMargins += overSideMargin + underSideMargin;
        }

        curr->setLogicalTop(newLogicalTop.toFloat());

        if (childAffectsTopBottomPos) {
            if (curr->renderer().isRubyRun()) {
                // Treat the leading on the first and last lines of ruby runs as not being part of the overall lineTop/lineBottom.
                // Really this is a workaround hack for the fact that ruby should have been done as line layout and not done using
                // inline-block.
                if (renderer().style()->isFlippedLinesWritingMode() == (curr->renderer().style()->rubyPosition() == RubyPositionAfter))
                    hasAnnotationsBefore = true;
                else
                    hasAnnotationsAfter = true;

                RenderRubyRun& rubyRun = toRenderRubyRun(curr->renderer());
                if (RenderRubyBase* rubyBase = rubyRun.rubyBase()) {
                    LayoutUnit bottomRubyBaseLeading = (curr->logicalHeight() - rubyBase->logicalBottom()) + rubyBase->logicalHeight() - (rubyBase->lastRootBox() ? rubyBase->lastRootBox()->lineBottom() : LayoutUnit());
                    LayoutUnit topRubyBaseLeading = rubyBase->logicalTop() + (rubyBase->firstRootBox() ? rubyBase->firstRootBox()->lineTop() : LayoutUnit());
                    newLogicalTop += !renderer().style()->isFlippedLinesWritingMode() ? topRubyBaseLeading : bottomRubyBaseLeading;
                    boxHeight -= (topRubyBaseLeading + bottomRubyBaseLeading);
                }
            }
            if (curr->isInlineTextBox()) {
                TextEmphasisPosition emphasisMarkPosition;
                if (toInlineTextBox(curr)->getEmphasisMarkPosition(curr->renderer().style(isFirstLineStyle()), emphasisMarkPosition)) {
                    bool emphasisMarkIsOver = emphasisMarkPosition == TextEmphasisPositionOver;
                    if (emphasisMarkIsOver != curr->renderer().style(isFirstLineStyle())->isFlippedLinesWritingMode())
                        hasAnnotationsBefore = true;
                    else
                        hasAnnotationsAfter = true;
                }
            }

            if (!setLineTop) {
                setLineTop = true;
                lineTop = newLogicalTop;
                lineTopIncludingMargins = min(lineTop, newLogicalTopIncludingMargins);
            } else {
                lineTop = min(lineTop, newLogicalTop);
                lineTopIncludingMargins = min(lineTop, min(lineTopIncludingMargins, newLogicalTopIncludingMargins));
            }
            lineBottom = max(lineBottom, newLogicalTop + boxHeight);
            lineBottomIncludingMargins = max(lineBottom, max(lineBottomIncludingMargins, newLogicalTopIncludingMargins + boxHeightIncludingMargins));
        }

        // Adjust boxes to use their real box y/height and not the logical height (as dictated by
        // line-height).
        if (inlineFlowBox)
            inlineFlowBox->placeBoxesInBlockDirection(top, maxHeight, maxAscent, strictMode, lineTop, lineBottom, setLineTop,
                                                      lineTopIncludingMargins, lineBottomIncludingMargins, hasAnnotationsBefore, hasAnnotationsAfter, baselineType);
    }

    if (isRootBox) {
        if (strictMode || hasTextChildren() || (descendantsHaveSameLineHeightAndBaseline() && hasTextDescendants())) {
            if (!setLineTop) {
                setLineTop = true;
                lineTop = pixelSnappedLogicalTop();
                lineTopIncludingMargins = lineTop;
            } else {
                lineTop = min<LayoutUnit>(lineTop, pixelSnappedLogicalTop());
                lineTopIncludingMargins = min(lineTop, lineTopIncludingMargins);
            }
            lineBottom = max<LayoutUnit>(lineBottom, pixelSnappedLogicalBottom());
            lineBottomIncludingMargins = max(lineBottom, lineBottomIncludingMargins);
        }

        if (renderer().style()->isFlippedLinesWritingMode())
            flipLinesInBlockDirection(lineTopIncludingMargins, lineBottomIncludingMargins);
    }
}

void InlineFlowBox::computeMaxLogicalTop(float& maxLogicalTop) const
{
    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
        if (curr->renderer().isOutOfFlowPositioned())
            continue; // Positioned placeholders don't affect calculations.

        if (descendantsHaveSameLineHeightAndBaseline())
            continue;

        maxLogicalTop = max<float>(maxLogicalTop, curr->y());
        float localMaxLogicalTop = 0;
        if (curr->isInlineFlowBox())
            toInlineFlowBox(curr)->computeMaxLogicalTop(localMaxLogicalTop);
        maxLogicalTop = max<float>(maxLogicalTop, localMaxLogicalTop);
    }
}

void InlineFlowBox::flipLinesInBlockDirection(LayoutUnit lineTop, LayoutUnit lineBottom)
{
    // Flip the box on the line such that the top is now relative to the lineBottom instead of the lineTop.
    setLogicalTop(lineBottom - (logicalTop() - lineTop) - logicalHeight());

    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
        if (curr->renderer().isOutOfFlowPositioned())
            continue; // Positioned placeholders aren't affected here.

        if (curr->isInlineFlowBox())
            toInlineFlowBox(curr)->flipLinesInBlockDirection(lineTop, lineBottom);
        else
            curr->setLogicalTop(lineBottom - (curr->logicalTop() - lineTop) - curr->logicalHeight());
    }
}

inline void InlineFlowBox::addBoxShadowVisualOverflow(LayoutRect& logicalVisualOverflow)
{
    // box-shadow on root line boxes is applying to the block and not to the lines.
    if (!parent())
        return;

    RenderStyle* style = renderer().style(isFirstLineStyle());
    if (!style->boxShadow())
        return;

    LayoutUnit boxShadowLogicalTop;
    LayoutUnit boxShadowLogicalBottom;
    style->getBoxShadowBlockDirectionExtent(boxShadowLogicalTop, boxShadowLogicalBottom);

    // Similar to how glyph overflow works, if our lines are flipped, then it's actually the opposite shadow that applies, since
    // the line is "upside down" in terms of block coordinates.
    LayoutUnit shadowLogicalTop = style->isFlippedLinesWritingMode() ? -boxShadowLogicalBottom : boxShadowLogicalTop;
    LayoutUnit shadowLogicalBottom = style->isFlippedLinesWritingMode() ? -boxShadowLogicalTop : boxShadowLogicalBottom;

    LayoutUnit logicalTopVisualOverflow = min(pixelSnappedLogicalTop() + shadowLogicalTop, logicalVisualOverflow.y());
    LayoutUnit logicalBottomVisualOverflow = max(pixelSnappedLogicalBottom() + shadowLogicalBottom, logicalVisualOverflow.maxY());

    LayoutUnit boxShadowLogicalLeft;
    LayoutUnit boxShadowLogicalRight;
    style->getBoxShadowInlineDirectionExtent(boxShadowLogicalLeft, boxShadowLogicalRight);

    LayoutUnit logicalLeftVisualOverflow = min(pixelSnappedLogicalLeft() + boxShadowLogicalLeft, logicalVisualOverflow.x());
    LayoutUnit logicalRightVisualOverflow = max(pixelSnappedLogicalRight() + boxShadowLogicalRight, logicalVisualOverflow.maxX());

    logicalVisualOverflow = LayoutRect(logicalLeftVisualOverflow, logicalTopVisualOverflow,
                                       logicalRightVisualOverflow - logicalLeftVisualOverflow, logicalBottomVisualOverflow - logicalTopVisualOverflow);
}

inline void InlineFlowBox::addBorderOutsetVisualOverflow(LayoutRect& logicalVisualOverflow)
{
    // border-image-outset on root line boxes is applying to the block and not to the lines.
    if (!parent())
        return;

    RenderStyle* style = renderer().style(isFirstLineStyle());
    if (!style->hasBorderImageOutsets())
        return;

    LayoutBoxExtent borderOutsets = style->borderImageOutsets();

    LayoutUnit borderOutsetLogicalTop = borderOutsets.logicalTop(style->writingMode());
    LayoutUnit borderOutsetLogicalBottom = borderOutsets.logicalBottom(style->writingMode());
    LayoutUnit borderOutsetLogicalLeft = borderOutsets.logicalLeft(style->writingMode());
    LayoutUnit borderOutsetLogicalRight = borderOutsets.logicalRight(style->writingMode());

    // Similar to how glyph overflow works, if our lines are flipped, then it's actually the opposite border that applies, since
    // the line is "upside down" in terms of block coordinates. vertical-rl and horizontal-bt are the flipped line modes.
    LayoutUnit outsetLogicalTop = style->isFlippedLinesWritingMode() ? borderOutsetLogicalBottom : borderOutsetLogicalTop;
    LayoutUnit outsetLogicalBottom = style->isFlippedLinesWritingMode() ? borderOutsetLogicalTop : borderOutsetLogicalBottom;

    LayoutUnit logicalTopVisualOverflow = min(pixelSnappedLogicalTop() - outsetLogicalTop, logicalVisualOverflow.y());
    LayoutUnit logicalBottomVisualOverflow = max(pixelSnappedLogicalBottom() + outsetLogicalBottom, logicalVisualOverflow.maxY());

    LayoutUnit outsetLogicalLeft = includeLogicalLeftEdge() ? borderOutsetLogicalLeft : LayoutUnit();
    LayoutUnit outsetLogicalRight = includeLogicalRightEdge() ? borderOutsetLogicalRight : LayoutUnit();

    LayoutUnit logicalLeftVisualOverflow = min(pixelSnappedLogicalLeft() - outsetLogicalLeft, logicalVisualOverflow.x());
    LayoutUnit logicalRightVisualOverflow = max(pixelSnappedLogicalRight() + outsetLogicalRight, logicalVisualOverflow.maxX());

    logicalVisualOverflow = LayoutRect(logicalLeftVisualOverflow, logicalTopVisualOverflow,
                                       logicalRightVisualOverflow - logicalLeftVisualOverflow, logicalBottomVisualOverflow - logicalTopVisualOverflow);
}

inline void InlineFlowBox::addOutlineVisualOverflow(LayoutRect& logicalVisualOverflow)
{
    // Outline on root line boxes is applied to the block and not to the lines.
    if (!parent())
        return;

    RenderStyle* style = renderer().style(isFirstLineStyle());
    if (!style->hasOutline())
        return;

    logicalVisualOverflow.inflate(style->outlineSize());
}

inline void InlineFlowBox::addTextBoxVisualOverflow(InlineTextBox* textBox, GlyphOverflowAndFallbackFontsMap& textBoxDataMap, LayoutRect& logicalVisualOverflow)
{
    if (textBox->knownToHaveNoOverflow())
        return;

    RenderStyle* style = textBox->renderer().style(isFirstLineStyle());

    GlyphOverflowAndFallbackFontsMap::iterator it = textBoxDataMap.find(textBox);
    GlyphOverflow* glyphOverflow = it == textBoxDataMap.end() ? 0 : &it->value.second;
    bool isFlippedLine = style->isFlippedLinesWritingMode();

    int topGlyphEdge = glyphOverflow ? (isFlippedLine ? glyphOverflow->bottom : glyphOverflow->top) : 0;
    int bottomGlyphEdge = glyphOverflow ? (isFlippedLine ? glyphOverflow->top : glyphOverflow->bottom) : 0;
    int leftGlyphEdge = glyphOverflow ? glyphOverflow->left : 0;
    int rightGlyphEdge = glyphOverflow ? glyphOverflow->right : 0;

    int strokeOverflow = static_cast<int>(ceilf(style->textStrokeWidth() / 2.0f));
    int topGlyphOverflow = -strokeOverflow - topGlyphEdge;
    int bottomGlyphOverflow = strokeOverflow + bottomGlyphEdge;
    int leftGlyphOverflow = -strokeOverflow - leftGlyphEdge;
    int rightGlyphOverflow = strokeOverflow + rightGlyphEdge;

    TextEmphasisPosition emphasisMarkPosition;
    if (style->textEmphasisMark() != TextEmphasisMarkNone && textBox->getEmphasisMarkPosition(style, emphasisMarkPosition)) {
        int emphasisMarkHeight = style->font().emphasisMarkHeight(style->textEmphasisMarkString());
        if ((emphasisMarkPosition == TextEmphasisPositionOver) == (!style->isFlippedLinesWritingMode()))
            topGlyphOverflow = min(topGlyphOverflow, -emphasisMarkHeight);
        else
            bottomGlyphOverflow = max(bottomGlyphOverflow, emphasisMarkHeight);
    }

    // If letter-spacing is negative, we should factor that into right layout overflow. (Even in RTL, letter-spacing is
    // applied to the right, so this is not an issue with left overflow.
    rightGlyphOverflow -= min(0, (int)style->font().fontDescription().letterSpacing());

    LayoutUnit textShadowLogicalTop;
    LayoutUnit textShadowLogicalBottom;
    style->getTextShadowBlockDirectionExtent(textShadowLogicalTop, textShadowLogicalBottom);

    LayoutUnit childOverflowLogicalTop = min<LayoutUnit>(textShadowLogicalTop + topGlyphOverflow, topGlyphOverflow);
    LayoutUnit childOverflowLogicalBottom = max<LayoutUnit>(textShadowLogicalBottom + bottomGlyphOverflow, bottomGlyphOverflow);

    LayoutUnit textShadowLogicalLeft;
    LayoutUnit textShadowLogicalRight;
    style->getTextShadowInlineDirectionExtent(textShadowLogicalLeft, textShadowLogicalRight);

    LayoutUnit childOverflowLogicalLeft = min<LayoutUnit>(textShadowLogicalLeft + leftGlyphOverflow, leftGlyphOverflow);
    LayoutUnit childOverflowLogicalRight = max<LayoutUnit>(textShadowLogicalRight + rightGlyphOverflow, rightGlyphOverflow);

    LayoutUnit logicalTopVisualOverflow = min(textBox->pixelSnappedLogicalTop() + childOverflowLogicalTop, logicalVisualOverflow.y());
    LayoutUnit logicalBottomVisualOverflow = max(textBox->pixelSnappedLogicalBottom() + childOverflowLogicalBottom, logicalVisualOverflow.maxY());
    LayoutUnit logicalLeftVisualOverflow = min(textBox->pixelSnappedLogicalLeft() + childOverflowLogicalLeft, logicalVisualOverflow.x());
    LayoutUnit logicalRightVisualOverflow = max(textBox->pixelSnappedLogicalRight() + childOverflowLogicalRight, logicalVisualOverflow.maxX());

    logicalVisualOverflow = LayoutRect(logicalLeftVisualOverflow, logicalTopVisualOverflow,
                                       logicalRightVisualOverflow - logicalLeftVisualOverflow, logicalBottomVisualOverflow - logicalTopVisualOverflow);

    textBox->setLogicalOverflowRect(logicalVisualOverflow);
}

inline void InlineFlowBox::addReplacedChildOverflow(const InlineBox* inlineBox, LayoutRect& logicalLayoutOverflow, LayoutRect& logicalVisualOverflow)
{
    RenderBox& box = toRenderBox(inlineBox->renderer());

    // Visual overflow only propagates if the box doesn't have a self-painting layer.  This rectangle does not include
    // transforms or relative positioning (since those objects always have self-painting layers), but it does need to be adjusted
    // for writing-mode differences.
    if (!box.hasSelfPaintingLayer()) {
        LayoutRect childLogicalVisualOverflow = box.logicalVisualOverflowRectForPropagation(renderer().style());
        childLogicalVisualOverflow.move(inlineBox->logicalLeft(), inlineBox->logicalTop());
        logicalVisualOverflow.unite(childLogicalVisualOverflow);
    }

    // Layout overflow internal to the child box only propagates if the child box doesn't have overflow clip set.
    // Otherwise the child border box propagates as layout overflow.  This rectangle must include transforms and relative positioning
    // and be adjusted for writing-mode differences.
    LayoutRect childLogicalLayoutOverflow = box.logicalLayoutOverflowRectForPropagation(renderer().style());
    childLogicalLayoutOverflow.move(inlineBox->logicalLeft(), inlineBox->logicalTop());
    logicalLayoutOverflow.unite(childLogicalLayoutOverflow);
}

void InlineFlowBox::computeOverflow(LayoutUnit lineTop, LayoutUnit lineBottom, GlyphOverflowAndFallbackFontsMap& textBoxDataMap)
{
    // If we know we have no overflow, we can just bail.
    if (knownToHaveNoOverflow()) {
        ASSERT(!m_overflow);
        return;
    }

    if (m_overflow)
        m_overflow.clear();

    // Visual overflow just includes overflow for stuff we need to repaint ourselves.  Self-painting layers are ignored.
    // Layout overflow is used to determine scrolling extent, so it still includes child layers and also factors in
    // transforms, relative positioning, etc.
    LayoutRect logicalLayoutOverflow(enclosingLayoutRect(logicalFrameRectIncludingLineHeight(lineTop, lineBottom)));
    LayoutRect logicalVisualOverflow(logicalLayoutOverflow);

    addBoxShadowVisualOverflow(logicalVisualOverflow);
    addBorderOutsetVisualOverflow(logicalVisualOverflow);
    addOutlineVisualOverflow(logicalVisualOverflow);

    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
        if (curr->renderer().isOutOfFlowPositioned())
            continue; // Positioned placeholders don't affect calculations.

        if (curr->renderer().isText()) {
            InlineTextBox* text = toInlineTextBox(curr);
            RenderText& rt = toRenderText(text->renderer());
            if (rt.isBR())
                continue;
            LayoutRect textBoxOverflow(enclosingLayoutRect(text->logicalFrameRect()));
            addTextBoxVisualOverflow(text, textBoxDataMap, textBoxOverflow);
            logicalVisualOverflow.unite(textBoxOverflow);
        } else if (curr->renderer().isRenderInline()) {
            InlineFlowBox* flow = toInlineFlowBox(curr);
            flow->computeOverflow(lineTop, lineBottom, textBoxDataMap);
            if (!flow->boxModelObject()->hasSelfPaintingLayer())
                logicalVisualOverflow.unite(flow->logicalVisualOverflowRect(lineTop, lineBottom));
            LayoutRect childLayoutOverflow = flow->logicalLayoutOverflowRect(lineTop, lineBottom);
            childLayoutOverflow.move(flow->boxModelObject()->relativePositionLogicalOffset());
            logicalLayoutOverflow.unite(childLayoutOverflow);
        } else {
            addReplacedChildOverflow(curr, logicalLayoutOverflow, logicalVisualOverflow);
        }
    }

    setOverflowFromLogicalRects(logicalLayoutOverflow, logicalVisualOverflow, lineTop, lineBottom);
}

void InlineFlowBox::setLayoutOverflow(const LayoutRect& rect, const LayoutRect& frameBox)
{
    if (frameBox.contains(rect) || rect.isEmpty())
        return;

    if (!m_overflow)
        m_overflow = adoptPtr(new RenderOverflow(frameBox, frameBox));

    m_overflow->setLayoutOverflow(rect);
}

void InlineFlowBox::setVisualOverflow(const LayoutRect& rect, const LayoutRect& frameBox)
{
    if (frameBox.contains(rect) || rect.isEmpty())
        return;

    if (!m_overflow)
        m_overflow = adoptPtr(new RenderOverflow(frameBox, frameBox));

    m_overflow->setVisualOverflow(rect);
}

void InlineFlowBox::setOverflowFromLogicalRects(const LayoutRect& logicalLayoutOverflow, const LayoutRect& logicalVisualOverflow, LayoutUnit lineTop, LayoutUnit lineBottom)
{
    LayoutRect frameBox = enclosingLayoutRect(frameRectIncludingLineHeight(lineTop, lineBottom));

    LayoutRect layoutOverflow(isHorizontal() ? logicalLayoutOverflow : logicalLayoutOverflow.transposedRect());
    setLayoutOverflow(layoutOverflow, frameBox);

    LayoutRect visualOverflow(isHorizontal() ? logicalVisualOverflow : logicalVisualOverflow.transposedRect());
    setVisualOverflow(visualOverflow, frameBox);
}

bool InlineFlowBox::nodeAtPoint(const HitTestRequest& request, HitTestResult& result, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, LayoutUnit lineTop, LayoutUnit lineBottom)
{
    LayoutRect overflowRect(visualOverflowRect(lineTop, lineBottom));
    flipForWritingMode(overflowRect);
    overflowRect.moveBy(accumulatedOffset);
    if (!locationInContainer.intersects(overflowRect))
        return false;

    // Check children first.
    // We need to account for culled inline parents of the hit-tested nodes, so that they may also get included in area-based hit-tests.
    RenderObject* culledParent = 0;
    for (InlineBox* curr = lastChild(); curr; curr = curr->prevOnLine()) {
        if (curr->renderer().isText() || !curr->boxModelObject()->hasSelfPaintingLayer()) {
            RenderObject* newParent = 0;
            // Culled parents are only relevant for area-based hit-tests, so ignore it in point-based ones.
            if (locationInContainer.isRectBasedTest()) {
                newParent = curr->renderer().parent();
                if (newParent == renderer())
                    newParent = 0;
            }
            // Check the culled parent after all its children have been checked, to do this we wait until
            // we are about to test an element with a different parent.
            if (newParent != culledParent) {
                if (!newParent || !newParent->isDescendantOf(culledParent)) {
                    while (culledParent && culledParent != renderer() && culledParent != newParent) {
                        if (culledParent->isRenderInline() && toRenderInline(culledParent)->hitTestCulledInline(request, result, locationInContainer, accumulatedOffset))
                            return true;
                        culledParent = culledParent->parent();
                    }
                }
                culledParent = newParent;
            }
            if (curr->nodeAtPoint(request, result, locationInContainer, accumulatedOffset, lineTop, lineBottom)) {
                renderer().updateHitTestResult(result, locationInContainer.point() - toLayoutSize(accumulatedOffset));
                return true;
            }
        }
    }
    // Check any culled ancestor of the final children tested.
    while (culledParent && culledParent != renderer()) {
        if (culledParent->isRenderInline() && toRenderInline(culledParent)->hitTestCulledInline(request, result, locationInContainer, accumulatedOffset))
            return true;
        culledParent = culledParent->parent();
    }

    // Now check ourselves. Pixel snap hit testing.
    LayoutRect frameRect = roundedFrameRect();
    LayoutUnit minX = frameRect.x();
    LayoutUnit minY = frameRect.y();
    LayoutUnit width = frameRect.width();
    LayoutUnit height = frameRect.height();

    // Constrain our hit testing to the line top and bottom if necessary.
    bool noQuirksMode = renderer().document().inNoQuirksMode();
    if (!noQuirksMode && !hasTextChildren() && !(descendantsHaveSameLineHeightAndBaseline() && hasTextDescendants())) {
        RootInlineBox& rootBox = root();
        LayoutUnit& top = isHorizontal() ? minY : minX;
        LayoutUnit& logicalHeight = isHorizontal() ? height : width;
        LayoutUnit bottom = min(rootBox.lineBottom(), top + logicalHeight);
        top = max(rootBox.lineTop(), top);
        logicalHeight = bottom - top;
    }

    // Move x/y to our coordinates.
    LayoutRect rect(minX, minY, width, height);
    flipForWritingMode(rect);
    rect.moveBy(accumulatedOffset);

    if (visibleToHitTestRequest(request) && locationInContainer.intersects(rect)) {
        renderer().updateHitTestResult(result, flipForWritingMode(locationInContainer.point() - toLayoutSize(accumulatedOffset))); // Don't add in m_x or m_y here, we want coords in the containing block's space.
        if (!result.addNodeToRectBasedTestResult(renderer().node(), request, locationInContainer, rect))
            return true;
    }

    return false;
}

void InlineFlowBox::paint(PaintInfo& paintInfo, const LayoutPoint& paintOffset, LayoutUnit lineTop, LayoutUnit lineBottom)
{
    LayoutRect overflowRect(visualOverflowRect(lineTop, lineBottom));
    flipForWritingMode(overflowRect);
    overflowRect.moveBy(paintOffset);

    if (!paintInfo.rect.intersects(pixelSnappedIntRect(overflowRect)))
        return;

    if (paintInfo.phase != PaintPhaseChildOutlines) {
        if (paintInfo.phase == PaintPhaseOutline || paintInfo.phase == PaintPhaseSelfOutline) {
            // Add ourselves to the paint info struct's list of inlines that need to paint their
            // outlines.
            if (renderer().style()->visibility() == VISIBLE && renderer().hasOutline() && !isRootInlineBox()) {
                RenderInline& inlineFlow = toRenderInline(renderer());

                RenderBlock* cb = 0;
                bool containingBlockPaintsContinuationOutline = inlineFlow.continuation() || inlineFlow.isInlineElementContinuation();
                if (containingBlockPaintsContinuationOutline) {
                    // FIXME: See https://bugs.webkit.org/show_bug.cgi?id=54690. We currently don't reconnect inline continuations
                    // after a child removal. As a result, those merged inlines do not get seperated and hence not get enclosed by
                    // anonymous blocks. In this case, it is better to bail out and paint it ourself.
                    RenderBlock* enclosingAnonymousBlock = renderer().containingBlock();
                    if (!enclosingAnonymousBlock->isAnonymousBlock())
                        containingBlockPaintsContinuationOutline = false;
                    else {
                        cb = enclosingAnonymousBlock->containingBlock();
                        for (RenderBoxModelObject* box = boxModelObject(); box != cb; box = box->parent()->enclosingBoxModelObject()) {
                            if (box->hasSelfPaintingLayer()) {
                                containingBlockPaintsContinuationOutline = false;
                                break;
                            }
                        }
                    }
                }

                if (containingBlockPaintsContinuationOutline) {
                    // Add ourselves to the containing block of the entire continuation so that it can
                    // paint us atomically.
                    cb->addContinuationWithOutline(toRenderInline(renderer().node()->renderer()));
                } else if (!inlineFlow.isInlineElementContinuation()) {
                    paintInfo.outlineObjects()->add(&inlineFlow);
                }
            }
        } else if (paintInfo.phase == PaintPhaseMask) {
            paintMask(paintInfo, paintOffset);
            return;
        } else {
            // Paint our background, border and box-shadow.
            paintBoxDecorations(paintInfo, paintOffset);
        }
    }

    if (paintInfo.phase == PaintPhaseMask)
        return;

    PaintPhase paintPhase = paintInfo.phase == PaintPhaseChildOutlines ? PaintPhaseOutline : paintInfo.phase;
    PaintInfo childInfo(paintInfo);
    childInfo.phase = paintPhase;
    childInfo.updatePaintingRootForChildren(&renderer());

    // Paint our children.
    if (paintPhase != PaintPhaseSelfOutline) {
        for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
            if (curr->renderer().isText() || !curr->boxModelObject()->hasSelfPaintingLayer())
                curr->paint(childInfo, paintOffset, lineTop, lineBottom);
        }
    }
}

void InlineFlowBox::paintFillLayers(const PaintInfo& paintInfo, const Color& c, const FillLayer* fillLayer, const LayoutRect& rect, CompositeOperator op)
{
    if (!fillLayer)
        return;
    paintFillLayers(paintInfo, c, fillLayer->next(), rect, op);
    paintFillLayer(paintInfo, c, fillLayer, rect, op);
}

bool InlineFlowBox::boxShadowCanBeAppliedToBackground(const FillLayer& lastBackgroundLayer) const
{
    // The checks here match how paintFillLayer() decides whether to clip (if it does, the shadow
    // would be clipped out, so it has to be drawn separately).
    StyleImage* image = lastBackgroundLayer.image();
    bool hasFillImage = image && image->canRender(&renderer(), renderer().style()->effectiveZoom());
    return (!hasFillImage && !renderer().style()->hasBorderRadius()) || (!prevLineBox() && !nextLineBox()) || !parent();
}

void InlineFlowBox::paintFillLayer(const PaintInfo& paintInfo, const Color& c, const FillLayer* fillLayer, const LayoutRect& rect, CompositeOperator op)
{
    StyleImage* img = fillLayer->image();
    bool hasFillImage = img && img->canRender(&renderer(), renderer().style()->effectiveZoom());
    if ((!hasFillImage && !renderer().style()->hasBorderRadius()) || (!prevLineBox() && !nextLineBox()) || !parent()) {
        boxModelObject()->paintFillLayerExtended(paintInfo, c, fillLayer, rect, BackgroundBleedNone, this, rect.size(), op);
    } else if (renderer().style()->boxDecorationBreak() == DCLONE) {
        GraphicsContextStateSaver stateSaver(*paintInfo.context);
        paintInfo.context->clip(LayoutRect(rect.x(), rect.y(), width(), height()));
        boxModelObject()->paintFillLayerExtended(paintInfo, c, fillLayer, rect, BackgroundBleedNone, this, rect.size(), op);
    } else {
        // We have a fill image that spans multiple lines.
        // We need to adjust tx and ty by the width of all previous lines.
        // Think of background painting on inlines as though you had one long line, a single continuous
        // strip.  Even though that strip has been broken up across multiple lines, you still paint it
        // as though you had one single line.  This means each line has to pick up the background where
        // the previous line left off.
        LayoutUnit logicalOffsetOnLine = 0;
        LayoutUnit totalLogicalWidth;
        if (renderer().style()->direction() == LTR) {
            for (InlineFlowBox* curr = prevLineBox(); curr; curr = curr->prevLineBox())
                logicalOffsetOnLine += curr->logicalWidth();
            totalLogicalWidth = logicalOffsetOnLine;
            for (InlineFlowBox* curr = this; curr; curr = curr->nextLineBox())
                totalLogicalWidth += curr->logicalWidth();
        } else {
            for (InlineFlowBox* curr = nextLineBox(); curr; curr = curr->nextLineBox())
                logicalOffsetOnLine += curr->logicalWidth();
            totalLogicalWidth = logicalOffsetOnLine;
            for (InlineFlowBox* curr = this; curr; curr = curr->prevLineBox())
                totalLogicalWidth += curr->logicalWidth();
        }
        LayoutUnit stripX = rect.x() - (isHorizontal() ? logicalOffsetOnLine : LayoutUnit());
        LayoutUnit stripY = rect.y() - (isHorizontal() ? LayoutUnit() : logicalOffsetOnLine);
        LayoutUnit stripWidth = isHorizontal() ? totalLogicalWidth : static_cast<LayoutUnit>(width());
        LayoutUnit stripHeight = isHorizontal() ? static_cast<LayoutUnit>(height()) : totalLogicalWidth;

        GraphicsContextStateSaver stateSaver(*paintInfo.context);
        paintInfo.context->clip(LayoutRect(rect.x(), rect.y(), width(), height()));
        boxModelObject()->paintFillLayerExtended(paintInfo, c, fillLayer, LayoutRect(stripX, stripY, stripWidth, stripHeight), BackgroundBleedNone, this, rect.size(), op);
    }
}

void InlineFlowBox::paintBoxShadow(const PaintInfo& info, RenderStyle* s, ShadowStyle shadowStyle, const LayoutRect& paintRect)
{
    if ((!prevLineBox() && !nextLineBox()) || !parent())
        boxModelObject()->paintBoxShadow(info, paintRect, s, shadowStyle);
    else {
        // FIXME: We can do better here in the multi-line case. We want to push a clip so that the shadow doesn't
        // protrude incorrectly at the edges, and we want to possibly include shadows cast from the previous/following lines
        boxModelObject()->paintBoxShadow(info, paintRect, s, shadowStyle, includeLogicalLeftEdge(), includeLogicalRightEdge());
    }
}

void InlineFlowBox::constrainToLineTopAndBottomIfNeeded(LayoutRect& rect) const
{
    bool noQuirksMode = renderer().document().inNoQuirksMode();
    if (!noQuirksMode && !hasTextChildren() && !(descendantsHaveSameLineHeightAndBaseline() && hasTextDescendants())) {
        const RootInlineBox& rootBox = root();
        LayoutUnit logicalTop = isHorizontal() ? rect.y() : rect.x();
        LayoutUnit logicalHeight = isHorizontal() ? rect.height() : rect.width();
        LayoutUnit bottom = min(rootBox.lineBottom(), logicalTop + logicalHeight);
        logicalTop = max(rootBox.lineTop(), logicalTop);
        logicalHeight = bottom - logicalTop;
        if (isHorizontal()) {
            rect.setY(logicalTop);
            rect.setHeight(logicalHeight);
        } else {
            rect.setX(logicalTop);
            rect.setWidth(logicalHeight);
        }
    }
}

static LayoutRect clipRectForNinePieceImageStrip(InlineFlowBox* box, const NinePieceImage& image, const LayoutRect& paintRect)
{
    LayoutRect clipRect(paintRect);
    RenderStyle* style = box->renderer().style();
    LayoutBoxExtent outsets = style->imageOutsets(image);
    if (box->isHorizontal()) {
        clipRect.setY(paintRect.y() - outsets.top());
        clipRect.setHeight(paintRect.height() + outsets.top() + outsets.bottom());
        if (box->includeLogicalLeftEdge()) {
            clipRect.setX(paintRect.x() - outsets.left());
            clipRect.setWidth(paintRect.width() + outsets.left());
        }
        if (box->includeLogicalRightEdge())
            clipRect.setWidth(clipRect.width() + outsets.right());
    } else {
        clipRect.setX(paintRect.x() - outsets.left());
        clipRect.setWidth(paintRect.width() + outsets.left() + outsets.right());
        if (box->includeLogicalLeftEdge()) {
            clipRect.setY(paintRect.y() - outsets.top());
            clipRect.setHeight(paintRect.height() + outsets.top());
        }
        if (box->includeLogicalRightEdge())
            clipRect.setHeight(clipRect.height() + outsets.bottom());
    }
    return clipRect;
}

void InlineFlowBox::paintBoxDecorations(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
{
    if (!paintInfo.shouldPaintWithinRoot(&renderer()) || renderer().style()->visibility() != VISIBLE || paintInfo.phase != PaintPhaseForeground)
        return;

    // Pixel snap background/border painting.
    LayoutRect frameRect = roundedFrameRect();

    constrainToLineTopAndBottomIfNeeded(frameRect);

    // Move x/y to our coordinates.
    LayoutRect localRect(frameRect);
    flipForWritingMode(localRect);
    LayoutPoint adjustedPaintoffset = paintOffset + localRect.location();

    GraphicsContext* context = paintInfo.context;

    // You can use p::first-line to specify a background. If so, the root line boxes for
    // a line may actually have to paint a background.
    RenderStyle* styleToUse = renderer().style(isFirstLineStyle());
    if ((!parent() && isFirstLineStyle() && styleToUse != renderer().style()) || (parent() && renderer().hasBoxDecorations())) {
        LayoutRect paintRect = LayoutRect(adjustedPaintoffset, frameRect.size());
        // Shadow comes first and is behind the background and border.
        if (!boxModelObject()->boxShadowShouldBeAppliedToBackground(BackgroundBleedNone, this))
            paintBoxShadow(paintInfo, styleToUse, Normal, paintRect);

        Color c = renderer().resolveColor(styleToUse, CSSPropertyBackgroundColor);
        paintFillLayers(paintInfo, c, styleToUse->backgroundLayers(), paintRect);
        paintBoxShadow(paintInfo, styleToUse, Inset, paintRect);

        // :first-line cannot be used to put borders on a line. Always paint borders with our
        // non-first-line style.
        if (parent() && renderer().style()->hasBorder()) {
            const NinePieceImage& borderImage = renderer().style()->borderImage();
            StyleImage* borderImageSource = borderImage.image();
            bool hasBorderImage = borderImageSource && borderImageSource->canRender(&renderer(), styleToUse->effectiveZoom());
            if (hasBorderImage && !borderImageSource->isLoaded())
                return; // Don't paint anything while we wait for the image to load.

            // The simple case is where we either have no border image or we are the only box for this object.  In those
            // cases only a single call to draw is required.
            if (!hasBorderImage || (!prevLineBox() && !nextLineBox()))
                boxModelObject()->paintBorder(paintInfo, paintRect, renderer().style(isFirstLineStyle()), BackgroundBleedNone, includeLogicalLeftEdge(), includeLogicalRightEdge());
            else {
                // We have a border image that spans multiple lines.
                // We need to adjust tx and ty by the width of all previous lines.
                // Think of border image painting on inlines as though you had one long line, a single continuous
                // strip.  Even though that strip has been broken up across multiple lines, you still paint it
                // as though you had one single line.  This means each line has to pick up the image where
                // the previous line left off.
                // FIXME: What the heck do we do with RTL here? The math we're using is obviously not right,
                // but it isn't even clear how this should work at all.
                LayoutUnit logicalOffsetOnLine = 0;
                for (InlineFlowBox* curr = prevLineBox(); curr; curr = curr->prevLineBox())
                    logicalOffsetOnLine += curr->logicalWidth();
                LayoutUnit totalLogicalWidth = logicalOffsetOnLine;
                for (InlineFlowBox* curr = this; curr; curr = curr->nextLineBox())
                    totalLogicalWidth += curr->logicalWidth();
                LayoutUnit stripX = adjustedPaintoffset.x() - (isHorizontal() ? logicalOffsetOnLine : LayoutUnit());
                LayoutUnit stripY = adjustedPaintoffset.y() - (isHorizontal() ? LayoutUnit() : logicalOffsetOnLine);
                LayoutUnit stripWidth = isHorizontal() ? totalLogicalWidth : frameRect.width();
                LayoutUnit stripHeight = isHorizontal() ? frameRect.height() : totalLogicalWidth;

                LayoutRect clipRect = clipRectForNinePieceImageStrip(this, borderImage, paintRect);
                GraphicsContextStateSaver stateSaver(*context);
                context->clip(clipRect);
                boxModelObject()->paintBorder(paintInfo, LayoutRect(stripX, stripY, stripWidth, stripHeight), renderer().style(isFirstLineStyle()));
            }
        }
    }
}

void InlineFlowBox::paintMask(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
{
    if (!paintInfo.shouldPaintWithinRoot(&renderer()) || renderer().style()->visibility() != VISIBLE || paintInfo.phase != PaintPhaseMask)
        return;

    // Pixel snap mask painting.
    LayoutRect frameRect = roundedFrameRect();

    constrainToLineTopAndBottomIfNeeded(frameRect);

    // Move x/y to our coordinates.
    LayoutRect localRect(frameRect);
    flipForWritingMode(localRect);
    LayoutPoint adjustedPaintOffset = paintOffset + localRect.location();

    const NinePieceImage& maskNinePieceImage = renderer().style()->maskBoxImage();
    StyleImage* maskBoxImage = renderer().style()->maskBoxImage().image();

    // Figure out if we need to push a transparency layer to render our mask.
    bool pushTransparencyLayer = false;
    bool compositedMask = renderer().hasLayer() && boxModelObject()->layer()->hasCompositedMask();
    bool flattenCompositingLayers = renderer().view()->frameView() && renderer().view()->frameView()->paintBehavior() & PaintBehaviorFlattenCompositingLayers;
    CompositeOperator compositeOp = CompositeSourceOver;
    if (!compositedMask || flattenCompositingLayers) {
        if ((maskBoxImage && renderer().style()->maskLayers()->hasImage()) || renderer().style()->maskLayers()->next())
            pushTransparencyLayer = true;

        compositeOp = CompositeDestinationIn;
        if (pushTransparencyLayer) {
            paintInfo.context->setCompositeOperation(CompositeDestinationIn);
            paintInfo.context->beginTransparencyLayer(1.0f);
            compositeOp = CompositeSourceOver;
        }
    }

    LayoutRect paintRect = LayoutRect(adjustedPaintOffset, frameRect.size());
    paintFillLayers(paintInfo, Color::transparent, renderer().style()->maskLayers(), paintRect, compositeOp);

    bool hasBoxImage = maskBoxImage && maskBoxImage->canRender(&renderer(), renderer().style()->effectiveZoom());
    if (!hasBoxImage || !maskBoxImage->isLoaded()) {
        if (pushTransparencyLayer)
            paintInfo.context->endLayer();
        return; // Don't paint anything while we wait for the image to load.
    }

    // The simple case is where we are the only box for this object.  In those
    // cases only a single call to draw is required.
    if (!prevLineBox() && !nextLineBox()) {
        boxModelObject()->paintNinePieceImage(paintInfo.context, LayoutRect(adjustedPaintOffset, frameRect.size()), renderer().style(), maskNinePieceImage, compositeOp);
    } else {
        // We have a mask image that spans multiple lines.
        // We need to adjust _tx and _ty by the width of all previous lines.
        LayoutUnit logicalOffsetOnLine = 0;
        for (InlineFlowBox* curr = prevLineBox(); curr; curr = curr->prevLineBox())
            logicalOffsetOnLine += curr->logicalWidth();
        LayoutUnit totalLogicalWidth = logicalOffsetOnLine;
        for (InlineFlowBox* curr = this; curr; curr = curr->nextLineBox())
            totalLogicalWidth += curr->logicalWidth();
        LayoutUnit stripX = adjustedPaintOffset.x() - (isHorizontal() ? logicalOffsetOnLine : LayoutUnit());
        LayoutUnit stripY = adjustedPaintOffset.y() - (isHorizontal() ? LayoutUnit() : logicalOffsetOnLine);
        LayoutUnit stripWidth = isHorizontal() ? totalLogicalWidth : frameRect.width();
        LayoutUnit stripHeight = isHorizontal() ? frameRect.height() : totalLogicalWidth;

        LayoutRect clipRect = clipRectForNinePieceImageStrip(this, maskNinePieceImage, paintRect);
        GraphicsContextStateSaver stateSaver(*paintInfo.context);
        paintInfo.context->clip(clipRect);
        boxModelObject()->paintNinePieceImage(paintInfo.context, LayoutRect(stripX, stripY, stripWidth, stripHeight), renderer().style(), maskNinePieceImage, compositeOp);
    }

    if (pushTransparencyLayer)
        paintInfo.context->endLayer();
}

InlineBox* InlineFlowBox::firstLeafChild() const
{
    InlineBox* leaf = 0;
    for (InlineBox* child = firstChild(); child && !leaf; child = child->nextOnLine())
        leaf = child->isLeaf() ? child : toInlineFlowBox(child)->firstLeafChild();
    return leaf;
}

InlineBox* InlineFlowBox::lastLeafChild() const
{
    InlineBox* leaf = 0;
    for (InlineBox* child = lastChild(); child && !leaf; child = child->prevOnLine())
        leaf = child->isLeaf() ? child : toInlineFlowBox(child)->lastLeafChild();
    return leaf;
}

RenderObject::SelectionState InlineFlowBox::selectionState()
{
    return RenderObject::SelectionNone;
}

bool InlineFlowBox::canAccommodateEllipsis(bool ltr, int blockEdge, int ellipsisWidth) const
{
    for (InlineBox *box = firstChild(); box; box = box->nextOnLine()) {
        if (!box->canAccommodateEllipsis(ltr, blockEdge, ellipsisWidth))
            return false;
    }
    return true;
}

float InlineFlowBox::placeEllipsisBox(bool ltr, float blockLeftEdge, float blockRightEdge, float ellipsisWidth, float &truncatedWidth, bool& foundBox)
{
    float result = -1;
    // We iterate over all children, the foundBox variable tells us when we've found the
    // box containing the ellipsis.  All boxes after that one in the flow are hidden.
    // If our flow is ltr then iterate over the boxes from left to right, otherwise iterate
    // from right to left. Varying the order allows us to correctly hide the boxes following the ellipsis.
    InlineBox* box = ltr ? firstChild() : lastChild();

    // NOTE: these will cross after foundBox = true.
    int visibleLeftEdge = blockLeftEdge;
    int visibleRightEdge = blockRightEdge;

    while (box) {
        int currResult = box->placeEllipsisBox(ltr, visibleLeftEdge, visibleRightEdge, ellipsisWidth, truncatedWidth, foundBox);
        if (currResult != -1 && result == -1)
            result = currResult;

        if (ltr) {
            visibleLeftEdge += box->logicalWidth();
            box = box->nextOnLine();
        }
        else {
            visibleRightEdge -= box->logicalWidth();
            box = box->prevOnLine();
        }
    }
    return result;
}

void InlineFlowBox::clearTruncation()
{
    for (InlineBox *box = firstChild(); box; box = box->nextOnLine())
        box->clearTruncation();
}

LayoutUnit InlineFlowBox::computeOverAnnotationAdjustment(LayoutUnit allowedPosition) const
{
    LayoutUnit result = 0;
    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
        if (curr->renderer().isOutOfFlowPositioned())
            continue; // Positioned placeholders don't affect calculations.

        if (curr->isInlineFlowBox())
            result = max(result, toInlineFlowBox(curr)->computeOverAnnotationAdjustment(allowedPosition));

        if (curr->renderer().isReplaced() && curr->renderer().isRubyRun() && curr->renderer().style()->rubyPosition() == RubyPositionBefore) {
            RenderRubyRun& rubyRun = toRenderRubyRun(curr->renderer());
            RenderRubyText* rubyText = rubyRun.rubyText();
            if (!rubyText)
                continue;

            if (!rubyRun.style()->isFlippedLinesWritingMode()) {
                LayoutUnit topOfFirstRubyTextLine = rubyText->logicalTop() + (rubyText->firstRootBox() ? rubyText->firstRootBox()->lineTop() : LayoutUnit());
                if (topOfFirstRubyTextLine >= 0)
                    continue;
                topOfFirstRubyTextLine += curr->logicalTop();
                result = max(result, allowedPosition - topOfFirstRubyTextLine);
            } else {
                LayoutUnit bottomOfLastRubyTextLine = rubyText->logicalTop() + (rubyText->lastRootBox() ? rubyText->lastRootBox()->lineBottom() : rubyText->logicalHeight());
                if (bottomOfLastRubyTextLine <= curr->logicalHeight())
                    continue;
                bottomOfLastRubyTextLine += curr->logicalTop();
                result = max(result, bottomOfLastRubyTextLine - allowedPosition);
            }
        }

        if (curr->isInlineTextBox()) {
            RenderStyle* style = curr->renderer().style(isFirstLineStyle());
            TextEmphasisPosition emphasisMarkPosition;
            if (style->textEmphasisMark() != TextEmphasisMarkNone && toInlineTextBox(curr)->getEmphasisMarkPosition(style, emphasisMarkPosition) && emphasisMarkPosition == TextEmphasisPositionOver) {
                if (!style->isFlippedLinesWritingMode()) {
                    int topOfEmphasisMark = curr->logicalTop() - style->font().emphasisMarkHeight(style->textEmphasisMarkString());
                    result = max(result, allowedPosition - topOfEmphasisMark);
                } else {
                    int bottomOfEmphasisMark = curr->logicalBottom() + style->font().emphasisMarkHeight(style->textEmphasisMarkString());
                    result = max(result, bottomOfEmphasisMark - allowedPosition);
                }
            }
        }
    }
    return result;
}

LayoutUnit InlineFlowBox::computeUnderAnnotationAdjustment(LayoutUnit allowedPosition) const
{
    LayoutUnit result = 0;
    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
        if (curr->renderer().isOutOfFlowPositioned())
            continue; // Positioned placeholders don't affect calculations.

        if (curr->isInlineFlowBox())
            result = max(result, toInlineFlowBox(curr)->computeUnderAnnotationAdjustment(allowedPosition));

        if (curr->renderer().isReplaced() && curr->renderer().isRubyRun() && curr->renderer().style()->rubyPosition() == RubyPositionAfter) {
            RenderRubyRun& rubyRun = toRenderRubyRun(curr->renderer());
            RenderRubyText* rubyText = rubyRun.rubyText();
            if (!rubyText)
                continue;

            if (rubyRun.style()->isFlippedLinesWritingMode()) {
                LayoutUnit topOfFirstRubyTextLine = rubyText->logicalTop() + (rubyText->firstRootBox() ? rubyText->firstRootBox()->lineTop() : LayoutUnit());
                if (topOfFirstRubyTextLine >= 0)
                    continue;
                topOfFirstRubyTextLine += curr->logicalTop();
                result = max(result, allowedPosition - topOfFirstRubyTextLine);
            } else {
                LayoutUnit bottomOfLastRubyTextLine = rubyText->logicalTop() + (rubyText->lastRootBox() ? rubyText->lastRootBox()->lineBottom() : rubyText->logicalHeight());
                if (bottomOfLastRubyTextLine <= curr->logicalHeight())
                    continue;
                bottomOfLastRubyTextLine += curr->logicalTop();
                result = max(result, bottomOfLastRubyTextLine - allowedPosition);
            }
        }

        if (curr->isInlineTextBox()) {
            RenderStyle* style = curr->renderer().style(isFirstLineStyle());
            if (style->textEmphasisMark() != TextEmphasisMarkNone && style->textEmphasisPosition() == TextEmphasisPositionUnder) {
                if (!style->isFlippedLinesWritingMode()) {
                    LayoutUnit bottomOfEmphasisMark = curr->logicalBottom() + style->font().emphasisMarkHeight(style->textEmphasisMarkString());
                    result = max(result, bottomOfEmphasisMark - allowedPosition);
                } else {
                    LayoutUnit topOfEmphasisMark = curr->logicalTop() - style->font().emphasisMarkHeight(style->textEmphasisMarkString());
                    result = max(result, allowedPosition - topOfEmphasisMark);
                }
            }
        }
    }
    return result;
}

void InlineFlowBox::collectLeafBoxesInLogicalOrder(Vector<InlineBox*>& leafBoxesInLogicalOrder, CustomInlineBoxRangeReverse customReverseImplementation, void* userData) const
{
    InlineBox* leaf = firstLeafChild();

    // FIXME: The reordering code is a copy of parts from BidiResolver::createBidiRunsForLine, operating directly on InlineBoxes, instead of BidiRuns.
    // Investigate on how this code could possibly be shared.
    unsigned char minLevel = 128;
    unsigned char maxLevel = 0;

    // First find highest and lowest levels, and initialize leafBoxesInLogicalOrder with the leaf boxes in visual order.
    for (; leaf; leaf = leaf->nextLeafChild()) {
        minLevel = min(minLevel, leaf->bidiLevel());
        maxLevel = max(maxLevel, leaf->bidiLevel());
        leafBoxesInLogicalOrder.append(leaf);
    }

    if (renderer().style()->rtlOrdering() == VisualOrder)
        return;

    // Reverse of reordering of the line (L2 according to Bidi spec):
    // L2. From the highest level found in the text to the lowest odd level on each line,
    // reverse any contiguous sequence of characters that are at that level or higher.

    // Reversing the reordering of the line is only done up to the lowest odd level.
    if (!(minLevel % 2))
        ++minLevel;

    Vector<InlineBox*>::iterator end = leafBoxesInLogicalOrder.end();
    while (minLevel <= maxLevel) {
        Vector<InlineBox*>::iterator it = leafBoxesInLogicalOrder.begin();
        while (it != end) {
            while (it != end) {
                if ((*it)->bidiLevel() >= minLevel)
                    break;
                ++it;
            }
            Vector<InlineBox*>::iterator first = it;
            while (it != end) {
                if ((*it)->bidiLevel() < minLevel)
                    break;
                ++it;
            }
            Vector<InlineBox*>::iterator last = it;
            if (customReverseImplementation) {
                ASSERT(userData);
                (*customReverseImplementation)(userData, first, last);
            } else
                std::reverse(first, last);
        }
        ++minLevel;
    }
}

#ifndef NDEBUG

const char* InlineFlowBox::boxName() const
{
    return "InlineFlowBox";
}

void InlineFlowBox::showLineTreeAndMark(const InlineBox* markedBox1, const char* markedLabel1, const InlineBox* markedBox2, const char* markedLabel2, const RenderObject* obj, int depth) const
{
    InlineBox::showLineTreeAndMark(markedBox1, markedLabel1, markedBox2, markedLabel2, obj, depth);
    for (const InlineBox* box = firstChild(); box; box = box->nextOnLine())
        box->showLineTreeAndMark(markedBox1, markedLabel1, markedBox2, markedLabel2, obj, depth + 1);
}

void InlineFlowBox::checkConsistency() const
{
#ifdef CHECK_CONSISTENCY
    ASSERT(!m_hasBadChildList);
    const InlineBox* prev = 0;
    for (const InlineBox* child = m_firstChild; child; child = child->nextOnLine()) {
        ASSERT(child->parent() == this);
        ASSERT(child->prevOnLine() == prev);
        prev = child;
    }
    ASSERT(prev == m_lastChild);
#endif
}

#endif

} // namespace WebCore