Merge WebKit at r75315: Initial merge by git.

Change-Id: I570314b346ce101c935ed22a626b48c2af266b84

1 files changed, 1358 insertions, 0 deletions

diff --git a/Source/WebCore/rendering/InlineFlowBox.cpp b/Source/WebCore/rendering/InlineFlowBox.cpp
new file mode 100644
index 0000000..75b23c5
--- /dev/null
+++ b/Source/WebCore/rendering/InlineFlowBox.cpp
@@ -0,0 +1,1358 @@
+/*
+ * 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 "InlineFlowBox.h"
+
+#include "CachedImage.h"
+#include "CSSPropertyNames.h"
+#include "Document.h"
+#include "EllipsisBox.h"
+#include "GraphicsContext.h"
+#include "InlineTextBox.h"
+#include "HitTestResult.h"
+#include "RootInlineBox.h"
+#include "RenderBlock.h"
+#include "RenderInline.h"
+#include "RenderLayer.h"
+#include "RenderListMarker.h"
+#include "RenderRubyBase.h"
+#include "RenderRubyRun.h"
+#include "RenderRubyText.h"
+#include "RenderTableCell.h"
+#include "RootInlineBox.h"
+#include "Text.h"
+#include "VerticalPositionCache.h"
+
+#include <math.h>
+
+using namespace std;
+
+namespace WebCore {
+
+#ifndef NDEBUG
+
+InlineFlowBox::~InlineFlowBox()
+{
+    if (!m_hasBadChildList)
+        for (InlineBox* child = firstChild(); child; child = child->nextOnLine())
+            child->setHasBadParent();
+}
+
+#endif
+
+int InlineFlowBox::getFlowSpacingLogicalWidth()
+{
+    int totWidth = marginBorderPaddingLogicalLeft() + marginBorderPaddingLogicalRight();
+    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
+        if (curr->isInlineFlowBox())
+            totWidth += static_cast<InlineFlowBox*>(curr)->getFlowSpacingLogicalWidth();
+    }
+    return totWidth;
+}
+
+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(m_firstLine);
+    child->setIsHorizontal(isHorizontal());
+    if (child->isText())
+        m_hasTextChildren = true;
+
+    checkConsistency();
+}
+
+void InlineFlowBox::removeChild(InlineBox* child)
+{
+    checkConsistency();
+
+    if (!m_dirty)
+        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(RenderArena* arena)
+{
+    InlineBox* child = firstChild();
+    InlineBox* next = 0;
+    while (child) {
+        ASSERT(this == child->parent());
+        next = child->nextOnLine();
+#ifndef NDEBUG
+        child->setParent(0);
+#endif
+        child->deleteLine(arena);
+        child = next;
+    }
+#ifndef NDEBUG
+    m_firstChild = 0;
+    m_lastChild = 0;
+#endif
+
+    removeLineBoxFromRenderObject();
+    destroy(arena);
+}
+
+void InlineFlowBox::removeLineBoxFromRenderObject()
+{
+    toRenderInline(renderer())->lineBoxes()->removeLineBox(this);
+}
+
+void InlineFlowBox::extractLine()
+{
+    if (!m_extracted)
+        extractLineBoxFromRenderObject();
+    for (InlineBox* child = firstChild(); child; child = child->nextOnLine())
+        child->extractLine();
+}
+
+void InlineFlowBox::extractLineBoxFromRenderObject()
+{
+    toRenderInline(renderer())->lineBoxes()->extractLineBox(this);
+}
+
+void InlineFlowBox::attachLine()
+{
+    if (m_extracted)
+        attachLineBoxToRenderObject();
+    for (InlineBox* child = firstChild(); child; child = child->nextOnLine())
+        child->attachLine();
+}
+
+void InlineFlowBox::attachLineBoxToRenderObject()
+{
+    toRenderInline(renderer())->lineBoxes()->attachLineBox(this);
+}
+
+void InlineFlowBox::adjustPosition(int dx, int 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);
+}
+
+RenderLineBoxList* InlineFlowBox::rendererLineBoxes() const
+{
+    return toRenderInline(renderer())->lineBoxes();
+}
+
+bool InlineFlowBox::onEndChain(RenderObject* endObject)
+{
+    if (!endObject)
+        return false;
+    
+    if (endObject == renderer())
+        return true;
+
+    RenderObject* curr = endObject;
+    RenderObject* parent = curr->parent();
+    while (parent && !parent->isRenderBlock()) {
+        if (parent->lastChild() != curr || parent == renderer())
+            return false;
+            
+        curr = parent;
+        parent = curr->parent();
+    }
+
+    return true;
+}
+
+void InlineFlowBox::determineSpacingForFlowBoxes(bool lastLine, RenderObject* endObject)
+{
+    // 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 (ltr && lineBoxList->firstLineBox() == this)
+                includeLeftEdge = true;
+            else if (!ltr && lineBoxList->lastLineBox() == this)
+                includeRightEdge = true;
+        }
+    
+        // In order to determine if the inline ends on this line, we check three things:
+        // (1) If we are the last line and we don't have a continuation(), then we can
+        // close up.
+        // (2) If the last line box for the flow has an object following it on the line (ltr,
+        // reverse for rtl), then the inline has closed.
+        // (3) The line may end on the inline.  If we are the last child (climbing up
+        // the end object's chain), then we just closed as well.
+        if (!lineBoxList->lastLineBox()->isConstructed()) {
+            RenderInline* inlineFlow = toRenderInline(renderer());
+            if (ltr) {
+                if (!nextLineBox() &&
+                    ((lastLine && !inlineFlow->continuation()) || nextOnLineExists() || onEndChain(endObject)))
+                    includeRightEdge = true;
+            } else {
+                if ((!prevLineBox() || prevLineBox()->isConstructed()) &&
+                    ((lastLine && !inlineFlow->continuation()) || prevOnLineExists() || onEndChain(endObject)))
+                    includeLeftEdge = true;
+            }
+        }
+    }
+
+    setEdges(includeLeftEdge, includeRightEdge);
+
+    // Recur into our children.
+    for (InlineBox* currChild = firstChild(); currChild; currChild = currChild->nextOnLine()) {
+        if (currChild->isInlineFlowBox()) {
+            InlineFlowBox* currFlow = static_cast<InlineFlowBox*>(currChild);
+            currFlow->determineSpacingForFlowBoxes(lastLine, endObject);
+        }
+    }
+}
+
+int InlineFlowBox::placeBoxesInInlineDirection(int logicalLeft, bool& needsWordSpacing, GlyphOverflowAndFallbackFontsMap& textBoxDataMap)
+{
+    // Set our x position.
+    setLogicalLeft(logicalLeft);
+  
+    int startLogicalLeft = logicalLeft;
+    logicalLeft += borderLogicalLeft() + paddingLogicalLeft();
+    
+    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
+        if (curr->renderer()->isText()) {
+            InlineTextBox* text = static_cast<InlineTextBox*>(curr);
+            RenderText* rt = toRenderText(text->renderer());
+            if (rt->textLength()) {
+                if (needsWordSpacing && isSpaceOrNewline(rt->characters()[text->start()]))
+                    logicalLeft += rt->style(m_firstLine)->font().wordSpacing();
+                needsWordSpacing = !isSpaceOrNewline(rt->characters()[text->end()]);
+            }
+            text->setLogicalLeft(logicalLeft);
+            logicalLeft += text->logicalWidth();
+        } else {
+            if (curr->renderer()->isPositioned()) {
+                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 = static_cast<InlineFlowBox*>(curr);
+                logicalLeft += flow->marginLogicalLeft();
+                logicalLeft = flow->placeBoxesInInlineDirection(logicalLeft, needsWordSpacing, textBoxDataMap);
+                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|.
+                int logicalLeftMargin = isHorizontal() ? curr->boxModelObject()->marginLeft() : curr->boxModelObject()->marginTop();
+                int logicalRightMargin = isHorizontal() ? curr->boxModelObject()->marginRight() : curr->boxModelObject()->marginBottom();
+                
+                logicalLeft += logicalLeftMargin;
+                curr->setLogicalLeft(logicalLeft);
+                logicalLeft += curr->logicalWidth() + logicalRightMargin;
+            }
+        }
+    }
+
+    logicalLeft += borderLogicalRight() + paddingLogicalRight();
+    setLogicalWidth(logicalLeft - startLogicalLeft);
+    return logicalLeft;
+}
+
+bool InlineFlowBox::requiresIdeographicBaseline(const GlyphOverflowAndFallbackFontsMap& textBoxDataMap) const
+{
+    if (isHorizontal())
+        return false;
+    
+    if (renderer()->style(m_firstLine)->font().primaryFont()->orientation() == Vertical)
+        return true;
+
+    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
+        if (curr->renderer()->isPositioned())
+            continue; // Positioned placeholders don't affect calculations.
+        
+        if (curr->isInlineFlowBox()) {
+            if (static_cast<InlineFlowBox*>(curr)->requiresIdeographicBaseline(textBoxDataMap))
+                return true;
+        } else {
+            if (curr->renderer()->style(m_firstLine)->font().primaryFont()->orientation() == Vertical)
+                return true;
+            
+            const Vector<const SimpleFontData*>* usedFonts = 0;
+            if (curr->isInlineTextBox()) {
+                GlyphOverflowAndFallbackFontsMap::const_iterator it = textBoxDataMap.find(static_cast<InlineTextBox*>(curr));
+                usedFonts = it == textBoxDataMap.end() ? 0 : &it->second.first;
+            }
+
+            if (usedFonts) {
+                for (size_t i = 0; i < usedFonts->size(); ++i) {
+                    if (usedFonts->at(i)->orientation() == Vertical)
+                        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()->isPositioned())
+            continue; // Positioned placeholders don't affect calculations.
+        if (curr->logicalTop() == PositionTop || curr->logicalTop() == PositionBottom) {
+            int lineHeight = curr->lineHeight();
+            if (curr->logicalTop() == PositionTop) {
+                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())
+            static_cast<InlineFlowBox*>(curr)->adjustMaxAscentAndDescent(maxAscent, maxDescent, maxPositionTop, maxPositionBottom);
+    }
+}
+
+static int verticalPositionForBox(InlineBox* box, FontBaseline baselineType, bool firstLine, VerticalPositionCache& verticalPositionCache)
+{
+    if (box->renderer()->isText())
+        return box->parent()->logicalTop();
+    
+    RenderBoxModelObject* renderer = box->boxModelObject();
+    ASSERT(renderer->isInline());
+    if (!renderer->isInline())
+        return 0;
+
+    // This method determines the vertical position for inline elements.
+    if (firstLine && !renderer->document()->usesFirstLineRules())
+        firstLine = false;
+
+    // Check the cache.
+    bool isRenderInline = renderer->isRenderInline();
+    if (isRenderInline && !firstLine) {
+        int verticalPosition = verticalPositionCache.get(renderer, baselineType);
+        if (verticalPosition != PositionUndefined)
+            return verticalPosition;
+    }
+
+    int verticalPosition = 0;
+    EVerticalAlign verticalAlign = renderer->style()->verticalAlign();
+    if (verticalAlign == TOP)
+        verticalPosition = PositionTop;
+    else if (verticalAlign == BOTTOM)
+        verticalPosition = PositionBottom;
+    else {
+        RenderObject* parent = renderer->parent();
+        if (parent->isRenderInline() && parent->style()->verticalAlign() != TOP && parent->style()->verticalAlign() != BOTTOM)
+            verticalPosition = box->parent()->logicalTop();
+        
+        if (verticalAlign != BASELINE) {
+            const Font& font = parent->style(firstLine)->font();
+            int fontSize = font.pixelSize();
+
+            LineDirectionMode lineDirection = parent->style()->isHorizontalWritingMode() ? HorizontalLine : VerticalLine;
+
+            if (verticalAlign == SUB)
+                verticalPosition += fontSize / 5 + 1;
+            else if (verticalAlign == SUPER)
+                verticalPosition -= fontSize / 3 + 1;
+            else if (verticalAlign == TEXT_TOP)
+                verticalPosition += renderer->baselinePosition(baselineType, firstLine, lineDirection) - font.ascent(baselineType);
+            else if (verticalAlign == MIDDLE)
+                verticalPosition += -static_cast<int>(font.xHeight() / 2) - renderer->lineHeight(firstLine, lineDirection) / 2 + renderer->baselinePosition(baselineType, firstLine, lineDirection);
+            else if (verticalAlign == TEXT_BOTTOM) {
+                verticalPosition += font.descent(baselineType);
+                // lineHeight - baselinePosition is always 0 for replaced elements (except inline blocks), so don't bother wasting time in that case.
+                if (!renderer->isReplaced() || renderer->isInlineBlockOrInlineTable())
+                    verticalPosition -= (renderer->lineHeight(firstLine, lineDirection) - renderer->baselinePosition(baselineType, firstLine, lineDirection));
+            } else if (verticalAlign == BASELINE_MIDDLE)
+                verticalPosition += -renderer->lineHeight(firstLine, lineDirection) / 2 + renderer->baselinePosition(baselineType, firstLine, lineDirection);
+            else if (verticalAlign == LENGTH)
+                verticalPosition -= renderer->style()->verticalAlignLength().calcValue(renderer->lineHeight(firstLine, lineDirection));
+        }
+    }
+
+    // Store the cached value.
+    if (isRenderInline && !firstLine)
+        verticalPositionCache.set(renderer, baselineType, verticalPosition);
+
+    return verticalPosition;
+}
+
+void InlineFlowBox::computeLogicalBoxHeights(int& maxPositionTop, int& 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.
+    //
+    // The maxAscent value represents the distance of the highest point of any box (including line-height) from
+    // the root box's baseline.  The maxDescent value represents the distance of the lowest point of any box
+    // (also 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 very 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. 
+    if (isRootInlineBox()) {
+        // Examine our root box.
+        int height = lineHeight();
+        int baseline = baselinePosition(baselineType);
+        if (hasTextChildren() || strictMode) {
+            int ascent = baseline;
+            int descent = height - ascent;
+            if (maxAscent < ascent || !setMaxAscent) {
+                maxAscent = ascent;
+                setMaxAscent = true;
+            }
+            if (maxDescent < descent || !setMaxDescent) {
+                maxDescent = descent;
+                setMaxDescent = true;
+            }
+        }
+    }
+
+    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
+        if (curr->renderer()->isPositioned())
+            continue; // Positioned placeholders don't affect calculations.
+        
+        bool isInlineFlow = curr->isInlineFlowBox();
+        
+        // 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 line-height) is above (for ascent) or below (for descent) the root box's baseline.
+        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(verticalPositionForBox(curr, baselineType, m_firstLine, verticalPositionCache));
+        
+        int lineHeight;
+        int baseline;
+        Vector<const SimpleFontData*>* usedFonts = 0;
+        if (curr->isInlineTextBox()) {
+            GlyphOverflowAndFallbackFontsMap::iterator it = textBoxDataMap.find(static_cast<InlineTextBox*>(curr));
+            usedFonts = it == textBoxDataMap.end() ? 0 : &it->second.first;
+        }
+
+        if (usedFonts && !usedFonts->isEmpty() && curr->renderer()->style(m_firstLine)->lineHeight().isNegative()) {
+            usedFonts->append(curr->renderer()->style(m_firstLine)->font().primaryFont());
+            bool baselineSet = false;
+            baseline = 0;
+            int baselineToBottom = 0;
+            for (size_t i = 0; i < usedFonts->size(); ++i) {
+                int halfLeading = (usedFonts->at(i)->lineSpacing() - usedFonts->at(i)->height()) / 2;
+                int usedFontBaseline = halfLeading + usedFonts->at(i)->ascent(baselineType);
+                int usedFontBaselineToBottom = usedFonts->at(i)->lineSpacing() - usedFontBaseline;
+                if (!baselineSet) {
+                    baselineSet = true;
+                    baseline = usedFontBaseline;
+                    baselineToBottom = usedFontBaselineToBottom;
+                } else {
+                    baseline = max(baseline, usedFontBaseline);
+                    baselineToBottom = max(baselineToBottom, usedFontBaselineToBottom);
+                }
+                if (!affectsAscent)
+                    affectsAscent = usedFonts->at(i)->ascent() - curr->logicalTop() > 0;
+                if (!affectsDescent)
+                    affectsDescent = usedFonts->at(i)->descent() + curr->logicalTop() > 0;
+            }
+            lineHeight = baseline + baselineToBottom;
+        } else {
+            lineHeight = curr->lineHeight();
+            baseline = curr->baselinePosition(baselineType);
+            if (curr->isText() || isInlineFlow) {
+                // Examine the font box for inline flows and text boxes to see if any part of it is above the baseline.
+                // If the top of our font box relative to the root box baseline is above the root box baseline, then
+                // we are contributing to the maxAscent value.
+                affectsAscent = curr->renderer()->style(m_firstLine)->font().ascent(baselineType) - curr->logicalTop() > 0;
+                
+                // Descent is similar.  If any part of our font box is below the root box's baseline, then
+                // we contribute to the maxDescent value.
+                affectsDescent = curr->renderer()->style(m_firstLine)->font().descent(baselineType) + curr->logicalTop() > 0;
+            } else {
+                // Replaced elements always affect both the ascent and descent.
+                affectsAscent = true;
+                affectsDescent = true;
+            }
+        }
+
+        if (curr->logicalTop() == PositionTop) {
+            if (maxPositionTop < lineHeight)
+                maxPositionTop = lineHeight;
+        } else if (curr->logicalTop() == PositionBottom) {
+            if (maxPositionBottom < lineHeight)
+                maxPositionBottom = lineHeight;
+        } else if ((!isInlineFlow || static_cast<InlineFlowBox*>(curr)->hasTextChildren()) || curr->boxModelObject()->hasInlineDirectionBordersOrPadding() || strictMode) {
+            // 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.
+            int ascent = baseline - curr->logicalTop();
+            int descent = lineHeight - ascent;
+            if (affectsAscent && (maxAscent < ascent || !setMaxAscent)) {
+                maxAscent = ascent;
+                setMaxAscent = true;
+            }
+            if (affectsDescent && (maxDescent < descent || !setMaxDescent)) {
+                maxDescent = descent;
+                setMaxDescent = true;
+            }
+        }
+
+        if (curr->isInlineFlowBox())
+            static_cast<InlineFlowBox*>(curr)->computeLogicalBoxHeights(maxPositionTop, maxPositionBottom, maxAscent, maxDescent,
+                                                                        setMaxAscent, setMaxDescent, strictMode, textBoxDataMap,
+                                                                        baselineType, verticalPositionCache);
+    }
+}
+
+void InlineFlowBox::placeBoxesInBlockDirection(int top, int maxHeight, int maxAscent, bool strictMode, int& lineTop, int& lineBottom, bool& setLineTop,
+                                               int& lineTopIncludingMargins, int& lineBottomIncludingMargins, bool& hasAnnotationsBefore, bool& hasAnnotationsAfter, FontBaseline baselineType)
+{
+    if (isRootInlineBox())
+        setLogicalTop(top + maxAscent - baselinePosition(baselineType)); // Place our root box.
+
+    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
+        if (curr->renderer()->isPositioned())
+            continue; // Positioned placeholders don't affect calculations.
+        
+        // Adjust boxes to use their real box y/height and not the logical height (as dictated by
+        // line-height).
+        bool isInlineFlow = curr->isInlineFlowBox();
+        if (isInlineFlow)
+            static_cast<InlineFlowBox*>(curr)->placeBoxesInBlockDirection(top, maxHeight, maxAscent, strictMode, lineTop, lineBottom, setLineTop,
+                                                                          lineTopIncludingMargins, lineBottomIncludingMargins, hasAnnotationsBefore, hasAnnotationsAfter, baselineType);
+
+        bool childAffectsTopBottomPos = true;
+        if (curr->logicalTop() == PositionTop)
+            curr->setLogicalTop(top);
+        else if (curr->logicalTop() == PositionBottom)
+            curr->setLogicalTop(top + maxHeight - curr->lineHeight());
+        else {
+            if ((isInlineFlow && !static_cast<InlineFlowBox*>(curr)->hasTextChildren()) && !curr->boxModelObject()->hasInlineDirectionBordersOrPadding() && !strictMode)
+                childAffectsTopBottomPos = false;
+            int posAdjust = maxAscent - curr->baselinePosition(baselineType);
+            curr->setLogicalTop(curr->logicalTop() + top + posAdjust);
+        }
+        
+        int newLogicalTop = curr->logicalTop();
+        int newLogicalTopIncludingMargins;
+        int boxHeight = curr->logicalHeight();
+        int boxHeightIncludingMargins = boxHeight;
+            
+        if (curr->isText() || curr->isInlineFlowBox()) {
+            const Font& font = curr->renderer()->style(m_firstLine)->font();
+            newLogicalTop += curr->baselinePosition(baselineType) - font.ascent(baselineType);
+            if (curr->isInlineFlowBox()) {
+                RenderBoxModelObject* boxObject = toRenderBoxModelObject(curr->renderer());
+                newLogicalTop -= boxObject->style(m_firstLine)->isHorizontalWritingMode() ? boxObject->borderTop() + boxObject->paddingTop() : 
+                                 boxObject->borderRight() + boxObject->paddingRight();
+            }
+            newLogicalTopIncludingMargins = newLogicalTop;
+        } else if (!curr->renderer()->isBR()) {
+            RenderBox* box = toRenderBox(curr->renderer());
+            newLogicalTopIncludingMargins = newLogicalTop;
+            int overSideMargin = curr->isHorizontal() ? box->marginTop() : box->marginRight();
+            int underSideMargin = curr->isHorizontal() ? box->marginBottom() : box->marginLeft();
+            newLogicalTop += overSideMargin;
+            boxHeightIncludingMargins += overSideMargin + underSideMargin;
+        }
+
+        curr->setLogicalTop(newLogicalTop);
+
+        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())
+                    hasAnnotationsBefore = true;
+                else
+                    hasAnnotationsAfter = true;
+
+                RenderRubyRun* rubyRun = static_cast<RenderRubyRun*>(curr->renderer());
+                if (RenderRubyBase* rubyBase = rubyRun->rubyBase()) {
+                    int bottomRubyBaseLeading = (curr->logicalHeight() - rubyBase->logicalBottom()) + rubyBase->logicalHeight() - (rubyBase->lastRootBox() ? rubyBase->lastRootBox()->lineBottom() : 0);
+                    int topRubyBaseLeading = rubyBase->logicalTop() + (rubyBase->firstRootBox() ? rubyBase->firstRootBox()->lineTop() : 0);
+                    newLogicalTop += !renderer()->style()->isFlippedLinesWritingMode() ? topRubyBaseLeading : bottomRubyBaseLeading;
+                    boxHeight -= (topRubyBaseLeading + bottomRubyBaseLeading);
+                }
+            }
+            if (curr->isInlineTextBox()) {
+                TextEmphasisPosition emphasisMarkPosition;
+                if (static_cast<InlineTextBox*>(curr)->getEmphasisMarkPosition(curr->renderer()->style(m_firstLine), emphasisMarkPosition)) {
+                    bool emphasisMarkIsOver = emphasisMarkPosition == TextEmphasisPositionOver;
+                    if (emphasisMarkIsOver != curr->renderer()->style(m_firstLine)->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));
+        }
+    }
+
+    if (isRootInlineBox()) {
+        const Font& font = renderer()->style(m_firstLine)->font();
+        setLogicalTop(logicalTop() + baselinePosition(baselineType) - font.ascent(baselineType));
+        
+        if (hasTextChildren() || strictMode) {
+            if (!setLineTop) {
+                setLineTop = true;
+                lineTop = logicalTop();
+                lineTopIncludingMargins = lineTop;
+            } else {
+                lineTop = min(lineTop, logicalTop());
+                lineTopIncludingMargins = min(lineTop, lineTopIncludingMargins);
+            }
+            lineBottom = max(lineBottom, logicalTop() + logicalHeight());
+            lineBottomIncludingMargins = max(lineBottom, lineBottomIncludingMargins);
+        }
+        
+        if (renderer()->style()->isFlippedLinesWritingMode())
+            flipLinesInBlockDirection(lineTopIncludingMargins, lineBottomIncludingMargins);
+    }
+}
+
+void InlineFlowBox::flipLinesInBlockDirection(int lineTop, int 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()->isPositioned())
+            continue; // Positioned placeholders aren't affected here.
+        
+        if (curr->isInlineFlowBox())
+            static_cast<InlineFlowBox*>(curr)->flipLinesInBlockDirection(lineTop, lineBottom);
+        else
+            curr->setLogicalTop(lineBottom - (curr->logicalTop() - lineTop) - curr->logicalHeight());
+    }
+}
+
+void InlineFlowBox::addBoxShadowVisualOverflow(IntRect& logicalVisualOverflow)
+{
+    if (!parent())
+        return; // Box-shadow doesn't apply to root line boxes.
+
+    int boxShadowLogicalTop;
+    int boxShadowLogicalBottom;
+    renderer()->style(m_firstLine)->getBoxShadowBlockDirectionExtent(boxShadowLogicalTop, boxShadowLogicalBottom);
+    
+    int logicalTopVisualOverflow = min(logicalTop() + boxShadowLogicalTop, logicalVisualOverflow.y());
+    int logicalBottomVisualOverflow = max(logicalBottom() + boxShadowLogicalBottom, logicalVisualOverflow.bottom());
+    
+    int boxShadowLogicalLeft;
+    int boxShadowLogicalRight;
+    renderer()->style(m_firstLine)->getBoxShadowInlineDirectionExtent(boxShadowLogicalLeft, boxShadowLogicalRight);
+
+    int logicalLeftVisualOverflow = min(logicalLeft() + boxShadowLogicalLeft, logicalVisualOverflow.x());
+    int logicalRightVisualOverflow = max(logicalRight() + boxShadowLogicalRight, logicalVisualOverflow.right());
+    
+    logicalVisualOverflow = IntRect(logicalLeftVisualOverflow, logicalTopVisualOverflow,
+                                    logicalRightVisualOverflow - logicalLeftVisualOverflow, logicalBottomVisualOverflow - logicalTopVisualOverflow);
+}
+
+void InlineFlowBox::addTextBoxVisualOverflow(const InlineTextBox* textBox, GlyphOverflowAndFallbackFontsMap& textBoxDataMap, IntRect& logicalVisualOverflow)
+{
+    RenderStyle* style = renderer()->style(m_firstLine);
+    int strokeOverflow = static_cast<int>(ceilf(style->textStrokeWidth() / 2.0f));
+
+    GlyphOverflowAndFallbackFontsMap::iterator it = textBoxDataMap.find(textBox);
+    GlyphOverflow* glyphOverflow = it == textBoxDataMap.end() ? 0 : &it->second.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 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.
+    int letterSpacing = min(0, (int)style->font().letterSpacing());
+    rightGlyphOverflow -= letterSpacing;
+
+    int textShadowLogicalTop;
+    int textShadowLogicalBottom;
+    style->getTextShadowBlockDirectionExtent(textShadowLogicalTop, textShadowLogicalBottom);
+    
+    int childOverflowLogicalTop = min(textShadowLogicalTop + topGlyphOverflow, topGlyphOverflow);
+    int childOverflowLogicalBottom = max(textShadowLogicalBottom + bottomGlyphOverflow, bottomGlyphOverflow);
+   
+    int textShadowLogicalLeft;
+    int textShadowLogicalRight;
+    style->getTextShadowInlineDirectionExtent(textShadowLogicalLeft, textShadowLogicalRight);
+   
+    int childOverflowLogicalLeft = min(textShadowLogicalLeft + leftGlyphOverflow, leftGlyphOverflow);
+    int childOverflowLogicalRight = max(textShadowLogicalRight + rightGlyphOverflow, rightGlyphOverflow);
+
+    int logicalTopVisualOverflow = min(textBox->logicalTop() + childOverflowLogicalTop, logicalVisualOverflow.y());
+    int logicalBottomVisualOverflow = max(textBox->logicalBottom() + childOverflowLogicalBottom, logicalVisualOverflow.bottom());
+    int logicalLeftVisualOverflow = min(textBox->logicalLeft() + childOverflowLogicalLeft, logicalVisualOverflow.x());
+    int logicalRightVisualOverflow = max(textBox->logicalRight() + childOverflowLogicalRight, logicalVisualOverflow.right());
+    
+    logicalVisualOverflow = IntRect(logicalLeftVisualOverflow, logicalTopVisualOverflow,
+                                    logicalRightVisualOverflow - logicalLeftVisualOverflow, logicalBottomVisualOverflow - logicalTopVisualOverflow);
+}
+
+void InlineFlowBox::addReplacedChildOverflow(const InlineBox* inlineBox, IntRect& logicalLayoutOverflow, IntRect& 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()) {
+        IntRect 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.
+    IntRect childLogicalLayoutOverflow = box->logicalLayoutOverflowRectForPropagation(renderer()->style());
+    childLogicalLayoutOverflow.move(inlineBox->logicalLeft(), inlineBox->logicalTop());
+    logicalLayoutOverflow.unite(childLogicalLayoutOverflow);
+}
+
+void InlineFlowBox::computeOverflow(int lineTop, int lineBottom, bool strictMode, GlyphOverflowAndFallbackFontsMap& textBoxDataMap)
+{
+    // Any spillage outside of the line top and bottom is not considered overflow.  We just ignore this, since it only happens
+    // from the "your ascent/descent don't affect the line" quirk.
+    int topOverflow = max(logicalTop(), lineTop);
+    int bottomOverflow = min(logicalBottom(), lineBottom);
+    
+    // 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.
+    IntRect logicalLayoutOverflow(logicalLeft(), topOverflow, logicalWidth(), bottomOverflow - topOverflow);
+    IntRect logicalVisualOverflow(logicalLayoutOverflow);
+  
+    // box-shadow on root line boxes is applying to the block and not to the lines.
+    addBoxShadowVisualOverflow(logicalVisualOverflow);
+
+    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
+        if (curr->renderer()->isPositioned())
+            continue; // Positioned placeholders don't affect calculations.
+        
+        if (curr->renderer()->isText()) {
+            InlineTextBox* text = static_cast<InlineTextBox*>(curr);
+            RenderText* rt = toRenderText(text->renderer());
+            if (rt->isBR())
+                continue;
+            addTextBoxVisualOverflow(text, textBoxDataMap, logicalVisualOverflow);
+        } else  if (curr->renderer()->isRenderInline()) {
+            InlineFlowBox* flow = static_cast<InlineFlowBox*>(curr);
+            flow->computeOverflow(lineTop, lineBottom, strictMode, textBoxDataMap);
+            if (!flow->boxModelObject()->hasSelfPaintingLayer())
+                logicalVisualOverflow.unite(flow->logicalVisualOverflowRect());
+            IntRect childLayoutOverflow = flow->logicalLayoutOverflowRect();
+            childLayoutOverflow.move(flow->boxModelObject()->relativePositionLogicalOffset());
+            logicalLayoutOverflow.unite(childLayoutOverflow);
+        } else
+            addReplacedChildOverflow(curr, logicalLayoutOverflow, logicalVisualOverflow);
+    }
+    
+    setOverflowFromLogicalRects(logicalLayoutOverflow, logicalVisualOverflow);
+}
+
+// FIXME: You will notice there is no contains() check here.  If the rect is smaller than the frame box it actually
+// becomes the new overflow.  The reason for this is that in quirks mode we don't let inline flow boxes paint
+// outside of the root line box's lineTop and lineBottom values.  We accomplish this visual clamping by actually
+// insetting the overflow rect so that it's smaller than the frame rect.
+//
+// The reason we don't just mutate the frameRect in quirks mode is that we'd have to put the m_height member variable
+// back into InlineBox.  Basically the tradeoff is 4 bytes in all modes (for m_height) added to InlineFlowBox, or
+// the allocation of a RenderOverflow struct for InlineFlowBoxes in quirks mode only.  For now, we're opting to award
+// the smaller memory consumption to strict mode pages.
+//
+// It might be possible to hash a custom height, or to require that lineTop and lineBottom be passed in to
+// all functions that query overflow.   
+void InlineFlowBox::setLayoutOverflow(const IntRect& rect)
+{
+    IntRect frameBox = frameRect();
+    if (frameBox == rect || rect.isEmpty())
+        return;
+        
+    if (!m_overflow)
+        m_overflow.set(new RenderOverflow(frameBox, frameBox));
+    
+    m_overflow->setLayoutOverflow(rect);
+}
+
+void InlineFlowBox::setVisualOverflow(const IntRect& rect)
+{
+    IntRect frameBox = frameRect();
+    if (frameBox == rect || rect.isEmpty())
+        return;
+        
+    if (!m_overflow)
+        m_overflow.set(new RenderOverflow(frameBox, frameBox));
+    
+    m_overflow->setVisualOverflow(rect);
+}
+
+void InlineFlowBox::setOverflowFromLogicalRects(const IntRect& logicalLayoutOverflow, const IntRect& logicalVisualOverflow)
+{
+    IntRect layoutOverflow(isHorizontal() ? logicalLayoutOverflow : logicalLayoutOverflow.transposedRect());
+    setLayoutOverflow(layoutOverflow);
+    
+    IntRect visualOverflow(isHorizontal() ? logicalVisualOverflow : logicalVisualOverflow.transposedRect());
+    setVisualOverflow(visualOverflow);
+}
+
+bool InlineFlowBox::nodeAtPoint(const HitTestRequest& request, HitTestResult& result, int x, int y, int tx, int ty)
+{
+    IntRect overflowRect(visualOverflowRect());
+    flipForWritingMode(overflowRect);
+    overflowRect.move(tx, ty);
+    if (!overflowRect.intersects(result.rectForPoint(x, y)))
+        return false;
+
+    // Check children first.
+    for (InlineBox* curr = lastChild(); curr; curr = curr->prevOnLine()) {
+        if ((curr->renderer()->isText() || !curr->boxModelObject()->hasSelfPaintingLayer()) && curr->nodeAtPoint(request, result, x, y, tx, ty)) {
+            renderer()->updateHitTestResult(result, IntPoint(x - tx, y - ty));
+            return true;
+        }
+    }
+
+    // Now check ourselves.
+    IntPoint boxOrigin = locationIncludingFlipping();
+    boxOrigin.move(tx, ty);
+    IntRect rect(boxOrigin, IntSize(width(), height()));
+    if (visibleToHitTesting() && rect.intersects(result.rectForPoint(x, y))) {
+        renderer()->updateHitTestResult(result, flipForWritingMode(IntPoint(x - tx, y - ty))); // Don't add in m_x or m_y here, we want coords in the containing block's space.
+        if (!result.addNodeToRectBasedTestResult(renderer()->node(), x, y, rect))
+            return true;
+    }
+    
+    return false;
+}
+
+void InlineFlowBox::paint(PaintInfo& paintInfo, int tx, int ty)
+{
+    IntRect overflowRect(visualOverflowRect());
+    overflowRect.inflate(renderer()->maximalOutlineSize(paintInfo.phase));
+    flipForWritingMode(overflowRect);
+    overflowRect.move(tx, ty);
+    
+    if (!paintInfo.rect.intersects(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) {
+                    cb = renderer()->containingBlock()->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, tx, ty);
+            return;
+        } else {
+            // Paint our background, border and box-shadow.
+            paintBoxDecorations(paintInfo, tx, ty);
+        }
+    }
+
+    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, tx, ty);
+        }
+    }
+}
+
+void InlineFlowBox::paintFillLayers(const PaintInfo& paintInfo, const Color& c, const FillLayer* fillLayer, int _tx, int _ty, int w, int h, CompositeOperator op)
+{
+    if (!fillLayer)
+        return;
+    paintFillLayers(paintInfo, c, fillLayer->next(), _tx, _ty, w, h, op);
+    paintFillLayer(paintInfo, c, fillLayer, _tx, _ty, w, h, op);
+}
+
+void InlineFlowBox::paintFillLayer(const PaintInfo& paintInfo, const Color& c, const FillLayer* fillLayer, int tx, int ty, int w, int h, CompositeOperator op)
+{
+    StyleImage* img = fillLayer->image();
+    bool hasFillImage = img && img->canRender(renderer()->style()->effectiveZoom());
+    if ((!hasFillImage && !renderer()->style()->hasBorderRadius()) || (!prevLineBox() && !nextLineBox()) || !parent())
+        boxModelObject()->paintFillLayerExtended(paintInfo, c, fillLayer, tx, ty, w, h, this, 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.
+        // 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.
+        int logicalOffsetOnLine = 0;
+        for (InlineFlowBox* curr = prevLineBox(); curr; curr = curr->prevLineBox())
+            logicalOffsetOnLine += curr->logicalWidth();
+        int totalLogicalWidth = logicalOffsetOnLine;
+        for (InlineFlowBox* curr = this; curr; curr = curr->nextLineBox())
+            totalLogicalWidth += curr->logicalWidth();
+        int stripX = tx - (isHorizontal() ? logicalOffsetOnLine : 0);
+        int stripY = ty - (isHorizontal() ? 0 : logicalOffsetOnLine);
+        int stripWidth = isHorizontal() ? totalLogicalWidth : width();
+        int stripHeight = isHorizontal() ? height() : totalLogicalWidth;
+        paintInfo.context->save();
+        paintInfo.context->clip(IntRect(tx, ty, width(), height()));
+        boxModelObject()->paintFillLayerExtended(paintInfo, c, fillLayer, stripX, stripY, stripWidth, stripHeight, this, op);
+        paintInfo.context->restore();
+    }
+}
+
+void InlineFlowBox::paintBoxShadow(GraphicsContext* context, RenderStyle* s, ShadowStyle shadowStyle, int tx, int ty, int w, int h)
+{
+    if ((!prevLineBox() && !nextLineBox()) || !parent())
+        boxModelObject()->paintBoxShadow(context, tx, ty, w, h, 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(context, tx, ty, w, h, s, shadowStyle, includeLogicalLeftEdge(), includeLogicalRightEdge());
+    }
+}
+
+void InlineFlowBox::paintBoxDecorations(PaintInfo& paintInfo, int tx, int ty)
+{
+    if (!paintInfo.shouldPaintWithinRoot(renderer()) || renderer()->style()->visibility() != VISIBLE || paintInfo.phase != PaintPhaseForeground)
+        return;
+
+    int x = m_x;
+    int y = m_y;
+    int w = width();
+    int h = height();
+
+    // Constrain our background/border painting to the line top and bottom if necessary.
+    bool noQuirksMode = renderer()->document()->inNoQuirksMode();
+    if (!hasTextChildren() && !noQuirksMode) {
+        RootInlineBox* rootBox = root();
+        int& top = isHorizontal() ? y : x;
+        int& logicalHeight = isHorizontal() ? h : w;
+        int bottom = min(rootBox->lineBottom(), top + logicalHeight);
+        top = max(rootBox->lineTop(), top);
+        logicalHeight = bottom - top;
+    }
+    
+    // Move x/y to our coordinates.
+    IntRect localRect(x, y, w, h);
+    flipForWritingMode(localRect);
+    tx += localRect.x();
+    ty += localRect.y();
+    
+    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(m_firstLine);
+    if ((!parent() && m_firstLine && styleToUse != renderer()->style()) || (parent() && renderer()->hasBoxDecorations())) {
+        // Shadow comes first and is behind the background and border.
+        if (styleToUse->boxShadow())
+            paintBoxShadow(context, styleToUse, Normal, tx, ty, w, h);
+
+        Color c = styleToUse->visitedDependentColor(CSSPropertyBackgroundColor);
+        paintFillLayers(paintInfo, c, styleToUse->backgroundLayers(), tx, ty, w, h);
+
+        if (styleToUse->boxShadow())
+            paintBoxShadow(context, styleToUse, Inset, tx, ty, w, h);
+
+        // :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()) {
+            StyleImage* borderImage = renderer()->style()->borderImage().image();
+            bool hasBorderImage = borderImage && borderImage->canRender(styleToUse->effectiveZoom());
+            if (hasBorderImage && !borderImage->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(context, tx, ty, w, h, renderer()->style(), 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.
+                int logicalOffsetOnLine = 0;
+                for (InlineFlowBox* curr = prevLineBox(); curr; curr = curr->prevLineBox())
+                    logicalOffsetOnLine += curr->logicalWidth();
+                int totalLogicalWidth = logicalOffsetOnLine;
+                for (InlineFlowBox* curr = this; curr; curr = curr->nextLineBox())
+                    totalLogicalWidth += curr->logicalWidth();
+                int stripX = tx - (isHorizontal() ? logicalOffsetOnLine : 0);
+                int stripY = ty - (isHorizontal() ? 0 : logicalOffsetOnLine);
+                int stripWidth = isHorizontal() ? totalLogicalWidth : w;
+                int stripHeight = isHorizontal() ? h : totalLogicalWidth;
+                context->save();
+                context->clip(IntRect(tx, ty, w, h));
+                boxModelObject()->paintBorder(context, stripX, stripY, stripWidth, stripHeight, renderer()->style());
+                context->restore();
+            }
+        }
+    }
+}
+
+void InlineFlowBox::paintMask(PaintInfo& paintInfo, int tx, int ty)
+{
+    if (!paintInfo.shouldPaintWithinRoot(renderer()) || renderer()->style()->visibility() != VISIBLE || paintInfo.phase != PaintPhaseMask)
+        return;
+
+    int x = m_x;
+    int y = m_y;
+    int w = width();
+    int h = height();
+
+    // Constrain our background/border painting to the line top and bottom if necessary.
+    bool noQuirksMode = renderer()->document()->inNoQuirksMode();
+    if (!hasTextChildren() && !noQuirksMode) {
+        RootInlineBox* rootBox = root();
+        int& top = isHorizontal() ? y : x;
+        int& logicalHeight = isHorizontal() ? h : w;
+        int bottom = min(rootBox->lineBottom(), top + logicalHeight);
+        top = max(rootBox->lineTop(), top);
+        logicalHeight = bottom - top;
+    }
+    
+    // Move x/y to our coordinates.
+    IntRect localRect(x, y, w, h);
+    flipForWritingMode(localRect);
+    tx += localRect.x();
+    ty += localRect.y();
+
+    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();
+    CompositeOperator compositeOp = CompositeSourceOver;
+    if (!compositedMask) {
+        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;
+        }
+    }
+
+    paintFillLayers(paintInfo, Color(), renderer()->style()->maskLayers(), tx, ty, w, h, compositeOp);
+    
+    bool hasBoxImage = maskBoxImage && maskBoxImage->canRender(renderer()->style()->effectiveZoom());
+    if (!hasBoxImage || !maskBoxImage->isLoaded())
+        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, tx, ty, w, h, 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.
+        int logicalOffsetOnLine = 0;
+        for (InlineFlowBox* curr = prevLineBox(); curr; curr = curr->prevLineBox())
+            logicalOffsetOnLine += curr->logicalWidth();
+        int totalLogicalWidth = logicalOffsetOnLine;
+        for (InlineFlowBox* curr = this; curr; curr = curr->nextLineBox())
+            totalLogicalWidth += curr->logicalWidth();
+        int stripX = tx - (isHorizontal() ? logicalOffsetOnLine : 0);
+        int stripY = ty - (isHorizontal() ? 0 : logicalOffsetOnLine);
+        int stripWidth = isHorizontal() ? totalLogicalWidth : w;
+        int stripHeight = isHorizontal() ? h : totalLogicalWidth;
+        paintInfo.context->save();
+        paintInfo.context->clip(IntRect(tx, ty, w, h));
+        boxModelObject()->paintNinePieceImage(paintInfo.context, stripX, stripY, stripWidth, stripHeight, renderer()->style(), maskNinePieceImage, compositeOp);
+        paintInfo.context->restore();
+    }
+    
+    if (pushTransparencyLayer)
+        paintInfo.context->endTransparencyLayer();
+}
+
+InlineBox* InlineFlowBox::firstLeafChild() const
+{
+    InlineBox* leaf = 0;
+    for (InlineBox* child = firstChild(); child && !leaf; child = child->nextOnLine())
+        leaf = child->isLeaf() ? child : static_cast<InlineFlowBox*>(child)->firstLeafChild();
+    return leaf;
+}
+
+InlineBox* InlineFlowBox::lastLeafChild() const
+{
+    InlineBox* leaf = 0;
+    for (InlineBox* child = lastChild(); child && !leaf; child = child->prevOnLine())
+        leaf = child->isLeaf() ? child : static_cast<InlineFlowBox*>(child)->lastLeafChild();
+    return leaf;
+}
+
+RenderObject::SelectionState InlineFlowBox::selectionState()
+{
+    return RenderObject::SelectionNone;
+}
+
+bool InlineFlowBox::canAccommodateEllipsis(bool ltr, int blockEdge, int ellipsisWidth)
+{
+    for (InlineBox *box = firstChild(); box; box = box->nextOnLine()) {
+        if (!box->canAccommodateEllipsis(ltr, blockEdge, ellipsisWidth))
+            return false;
+    }
+    return true;
+}
+
+int InlineFlowBox::placeEllipsisBox(bool ltr, int blockLeftEdge, int blockRightEdge, int ellipsisWidth, bool& foundBox)
+{
+    int 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, 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();
+}
+
+int InlineFlowBox::computeOverAnnotationAdjustment(int allowedPosition) const
+{
+    int result = 0;
+    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
+        if (curr->renderer()->isPositioned())
+            continue; // Positioned placeholders don't affect calculations.
+        
+        if (curr->isInlineFlowBox())
+            result = max(result, static_cast<InlineFlowBox*>(curr)->computeOverAnnotationAdjustment(allowedPosition));
+        
+        if (curr->renderer()->isReplaced() && curr->renderer()->isRubyRun()) {
+            RenderRubyRun* rubyRun = static_cast<RenderRubyRun*>(curr->renderer());
+            RenderRubyText* rubyText = rubyRun->rubyText();
+            if (!rubyText)
+                continue;
+            
+            if (!rubyRun->style()->isFlippedLinesWritingMode()) {
+                int topOfFirstRubyTextLine = rubyText->logicalTop() + (rubyText->firstRootBox() ? rubyText->firstRootBox()->lineTop() : 0);
+                if (topOfFirstRubyTextLine >= 0)
+                    continue;
+                topOfFirstRubyTextLine += curr->logicalTop();
+                result = max(result, allowedPosition - topOfFirstRubyTextLine);
+            } else {
+                int 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(m_firstLine);
+            TextEmphasisPosition emphasisMarkPosition;
+            if (style->textEmphasisMark() != TextEmphasisMarkNone && static_cast<InlineTextBox*>(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;
+}
+
+int InlineFlowBox::computeUnderAnnotationAdjustment(int allowedPosition) const
+{
+    int result = 0;
+    for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
+        if (curr->renderer()->isPositioned())
+            continue; // Positioned placeholders don't affect calculations.
+
+        if (curr->isInlineFlowBox())
+            result = max(result, static_cast<InlineFlowBox*>(curr)->computeUnderAnnotationAdjustment(allowedPosition));
+
+        if (curr->isInlineTextBox()) {
+            RenderStyle* style = curr->renderer()->style(m_firstLine);
+            if (style->textEmphasisMark() != TextEmphasisMarkNone && style->textEmphasisPosition() == TextEmphasisPositionUnder) {
+                if (!style->isFlippedLinesWritingMode()) {
+                    int bottomOfEmphasisMark = curr->logicalBottom() + style->font().emphasisMarkHeight(style->textEmphasisMarkString());
+                    result = max(result, bottomOfEmphasisMark - allowedPosition);
+                } else {
+                    int topOfEmphasisMark = curr->logicalTop() - style->font().emphasisMarkHeight(style->textEmphasisMarkString());
+                    result = max(result, allowedPosition - topOfEmphasisMark);
+                }
+            }
+        }
+    }
+    return result;
+}
+
+#ifndef NDEBUG
+
+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