Source/WebCore/rendering/mathml/RenderMathMLFraction.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 2009 Alex Milowski (alex@milowski.com). All rights reserved.
  * Copyright (C) 2010 François Sausset (sausset@gmail.com). All rights reserved.
  * Copyright (C) 2016 Igalia S.L.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "config.h"
 #include "RenderMathMLFraction.h"

 #if ENABLE(MATHML)

 #include "GraphicsContext.h"
 #include "MathMLFractionElement.h"
 #include "PaintInfo.h"
 #include <cmath>
 #include <wtf/IsoMallocInlines.h>

 namespace WebCore {

 WTF_MAKE_ISO_ALLOCATED_IMPL(RenderMathMLFraction);

 RenderMathMLFraction::RenderMathMLFraction(MathMLFractionElement& element, RenderStyle&& style)
     : RenderMathMLBlock(element, WTFMove(style))
 {
 }

 bool RenderMathMLFraction::isValid() const
 {
     // Verify whether the list of children is valid:
     // <mfrac> numerator denominator </mfrac>
     auto* child = firstChildBox();
     if (!child)
         return false;
     child = child->nextSiblingBox();
     return child && !child->nextSiblingBox();
 }

 RenderBox& RenderMathMLFraction::numerator() const
 {
     ASSERT(isValid());
     return *firstChildBox();
 }

 RenderBox& RenderMathMLFraction::denominator() const
 {
     ASSERT(isValid());
     return *firstChildBox()->nextSiblingBox();
 }

 LayoutUnit RenderMathMLFraction::defaultLineThickness() const
 {
     const auto& primaryFont = style().fontCascade().primaryFont();
     if (const auto* mathData = primaryFont.mathData())
         return LayoutUnit(mathData->getMathConstant(primaryFont, OpenTypeMathData::FractionRuleThickness));
     return ruleThicknessFallback();
 }

 LayoutUnit RenderMathMLFraction::lineThickness() const
 {
     return std::max<LayoutUnit>(toUserUnits(element().lineThickness(), style(), defaultLineThickness()), 0);
 }

 float RenderMathMLFraction::relativeLineThickness() const
 {
     if (LayoutUnit defaultThickness = defaultLineThickness())
         return lineThickness() / defaultThickness;
     return 0;
 }

 RenderMathMLFraction::FractionParameters RenderMathMLFraction::fractionParameters() const
 {
     // See https://mathml-refresh.github.io/mathml-core/#fraction-with-nonzero-line-thickness.

     ASSERT(lineThickness());
     FractionParameters parameters;
     LayoutUnit numeratorGapMin, denominatorGapMin, numeratorMinShiftUp, denominatorMinShiftDown;

     // We try and read constants to draw the fraction from the OpenType MATH and use fallback values otherwise.
     const auto& primaryFont = style().fontCascade().primaryFont();
     const auto* mathData = style().fontCascade().primaryFont().mathData();
     bool display = mathMLStyle().displayStyle();
     if (mathData) {
         numeratorGapMin = mathData->getMathConstant(primaryFont, display ? OpenTypeMathData::FractionNumDisplayStyleGapMin : OpenTypeMathData::FractionNumeratorGapMin);
         denominatorGapMin = mathData->getMathConstant(primaryFont, display ? OpenTypeMathData::FractionDenomDisplayStyleGapMin : OpenTypeMathData::FractionDenominatorGapMin);
         numeratorMinShiftUp = mathData->getMathConstant(primaryFont, display ? OpenTypeMathData::FractionNumeratorDisplayStyleShiftUp : OpenTypeMathData::FractionNumeratorShiftUp);
         denominatorMinShiftDown = mathData->getMathConstant(primaryFont, display ? OpenTypeMathData::FractionDenominatorDisplayStyleShiftDown : OpenTypeMathData::FractionDenominatorShiftDown);
     } else {
         // The MATH table specification suggests default rule thickness or (in displaystyle) 3 times default rule thickness for the gaps.
         numeratorGapMin = display ? 3 * ruleThicknessFallback() : ruleThicknessFallback();
         denominatorGapMin = numeratorGapMin;

         // The MATH table specification does not suggest any values for shifts, so we leave them at zero.
         numeratorMinShiftUp = 0;
         denominatorMinShiftDown = 0;
     }

     // Adjust fraction shifts to satisfy min gaps.
     LayoutUnit numeratorAscent = ascentForChild(numerator());
     LayoutUnit numeratorDescent = numerator().logicalHeight() - numeratorAscent;
     LayoutUnit denominatorAscent = ascentForChild(denominator());
     LayoutUnit thickness = lineThickness();
     parameters.numeratorShiftUp = std::max(numeratorMinShiftUp, mathAxisHeight() + thickness / 2 + numeratorGapMin + numeratorDescent);
     parameters.denominatorShiftDown = std::max(denominatorMinShiftDown, thickness / 2 + denominatorGapMin + denominatorAscent - mathAxisHeight());

     return parameters;
 }

 RenderMathMLFraction::FractionParameters RenderMathMLFraction::stackParameters() const
 {
     // See https://mathml-refresh.github.io/mathml-core/#fraction-with-zero-line-thickness.

     ASSERT(!lineThickness());
     ASSERT(isValid());
     FractionParameters parameters;
     LayoutUnit gapMin;

     // We try and read constants to draw the stack from the OpenType MATH and use fallback values otherwise.
     const auto& primaryFont = style().fontCascade().primaryFont();
     const auto* mathData = style().fontCascade().primaryFont().mathData();
     bool display = mathMLStyle().displayStyle();
     if (mathData) {
         gapMin = mathData->getMathConstant(primaryFont, display ? OpenTypeMathData::StackDisplayStyleGapMin : OpenTypeMathData::StackGapMin);
         parameters.numeratorShiftUp = mathData->getMathConstant(primaryFont, display ? OpenTypeMathData::StackTopDisplayStyleShiftUp : OpenTypeMathData::StackTopShiftUp);
         parameters.denominatorShiftDown = mathData->getMathConstant(primaryFont, display ? OpenTypeMathData::StackBottomDisplayStyleShiftDown : OpenTypeMathData::StackBottomShiftDown);
     } else {
         // We use the values suggested in the MATH table specification.
         gapMin = display ? 7 * ruleThicknessFallback() : 3 * ruleThicknessFallback();

         // The MATH table specification does not suggest any values for shifts, so we leave them at zero.
         parameters.numeratorShiftUp = 0;
         parameters.denominatorShiftDown = 0;
     }

     // Adjust fraction shifts to satisfy min gaps.
     LayoutUnit numeratorAscent = ascentForChild(numerator());
     LayoutUnit numeratorDescent = numerator().logicalHeight() - numeratorAscent;
     LayoutUnit denominatorAscent = ascentForChild(denominator());
     LayoutUnit gap = parameters.numeratorShiftUp - numeratorDescent + parameters.denominatorShiftDown - denominatorAscent;
     if (gap < gapMin) {
         LayoutUnit delta = (gapMin - gap) / 2;
         parameters.numeratorShiftUp += delta;
         parameters.denominatorShiftDown += delta;
     }

     return parameters;
 }

 RenderMathMLOperator* RenderMathMLFraction::unembellishedOperator() const
 {
     if (!isValid() || !is<RenderMathMLBlock>(numerator()))
         return nullptr;

     return downcast<RenderMathMLBlock>(numerator()).unembellishedOperator();
 }

 void RenderMathMLFraction::computePreferredLogicalWidths()
 {
     ASSERT(preferredLogicalWidthsDirty());

     m_minPreferredLogicalWidth = 0;
     m_maxPreferredLogicalWidth = 0;

     if (isValid()) {
         LayoutUnit numeratorWidth = numerator().maxPreferredLogicalWidth();
         LayoutUnit denominatorWidth = denominator().maxPreferredLogicalWidth();
         m_minPreferredLogicalWidth = m_maxPreferredLogicalWidth = std::max(numeratorWidth, denominatorWidth);
     }

     setPreferredLogicalWidthsDirty(false);
 }

 LayoutUnit RenderMathMLFraction::horizontalOffset(RenderBox& child, MathMLFractionElement::FractionAlignment align) const
 {
     switch (align) {
     case MathMLFractionElement::FractionAlignmentRight:
         return LayoutUnit(logicalWidth() - child.logicalWidth());
     case MathMLFractionElement::FractionAlignmentCenter:
         return LayoutUnit((logicalWidth() - child.logicalWidth()) / 2);
     case MathMLFractionElement::FractionAlignmentLeft:
         return 0_lu;
     }

     ASSERT_NOT_REACHED();
     return 0_lu;
 }

 LayoutUnit RenderMathMLFraction::fractionAscent() const
 {
     ASSERT(isValid());

     LayoutUnit numeratorAscent = ascentForChild(numerator());
     if (LayoutUnit thickness = lineThickness())
         return std::max(mathAxisHeight() + thickness / 2, numeratorAscent + fractionParameters().numeratorShiftUp);

     return numeratorAscent + stackParameters().numeratorShiftUp;
 }

 void RenderMathMLFraction::layoutBlock(bool relayoutChildren, LayoutUnit)
 {
     ASSERT(needsLayout());

     if (!relayoutChildren && simplifiedLayout())
         return;

     if (!isValid()) {
         layoutInvalidMarkup(relayoutChildren);
         return;
     }

     numerator().layoutIfNeeded();
     denominator().layoutIfNeeded();

     setLogicalWidth(std::max(numerator().logicalWidth(), denominator().logicalWidth()));

     LayoutUnit verticalOffset; // This is the top of the renderer.
     LayoutPoint numeratorLocation(horizontalOffset(numerator(), element().numeratorAlignment()), verticalOffset);
     numerator().setLocation(numeratorLocation);

     LayoutUnit denominatorAscent = ascentForChild(denominator());
     verticalOffset = fractionAscent();
     FractionParameters parameters = lineThickness() ? fractionParameters() : stackParameters();
     verticalOffset += parameters.denominatorShiftDown - denominatorAscent;

     LayoutPoint denominatorLocation(horizontalOffset(denominator(), element().denominatorAlignment()), verticalOffset);
     denominator().setLocation(denominatorLocation);

     verticalOffset += denominator().logicalHeight(); // This is the bottom of our renderer.
     setLogicalHeight(verticalOffset);

     layoutPositionedObjects(relayoutChildren);

     updateScrollInfoAfterLayout();

     clearNeedsLayout();
 }

 void RenderMathMLFraction::paint(PaintInfo& info, const LayoutPoint& paintOffset)
 {
     RenderMathMLBlock::paint(info, paintOffset);
     LayoutUnit thickness = lineThickness();
     if (info.context().paintingDisabled() || info.phase != PaintPhase::Foreground || style().visibility() != Visibility::Visible || !isValid() || !thickness)
         return;

     IntPoint adjustedPaintOffset = roundedIntPoint(paintOffset + location() + LayoutPoint(0_lu, fractionAscent() - mathAxisHeight()));

     GraphicsContextStateSaver stateSaver(info.context());

     info.context().setStrokeThickness(thickness);
     info.context().setStrokeStyle(SolidStroke);
     info.context().setStrokeColor(style().visitedDependentColorWithColorFilter(CSSPropertyColor));
     info.context().drawLine(adjustedPaintOffset, roundedIntPoint(LayoutPoint(adjustedPaintOffset.x() + logicalWidth(), LayoutUnit(adjustedPaintOffset.y()))));
 }

 Optional<int> RenderMathMLFraction::firstLineBaseline() const
 {
     if (isValid())
         return Optional<int>(std::lround(static_cast<float>(fractionAscent())));
     return RenderMathMLBlock::firstLineBaseline();
 }

 }

 #endif // ENABLE(MATHML)
	/*
	* Copyright (C) 2009 Alex Milowski (alex@milowski.com). All rights reserved.
	* Copyright (C) 2010 François Sausset (sausset@gmail.com). All rights reserved.
	* Copyright (C) 2016 Igalia S.L.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "config.h"
	#include "RenderMathMLFraction.h"

	#if ENABLE(MATHML)

	#include "GraphicsContext.h"
	#include "MathMLFractionElement.h"
	#include "PaintInfo.h"
	#include <cmath>
	#include <wtf/IsoMallocInlines.h>

	namespace WebCore {

	WTF_MAKE_ISO_ALLOCATED_IMPL(RenderMathMLFraction);

	RenderMathMLFraction::RenderMathMLFraction(MathMLFractionElement& element, RenderStyle&& style)
	: RenderMathMLBlock(element, WTFMove(style))
	{
	}

	bool RenderMathMLFraction::isValid() const
	{
	// Verify whether the list of children is valid:
	// <mfrac> numerator denominator </mfrac>
	auto* child = firstChildBox();
	if (!child)
	return false;
	child = child->nextSiblingBox();
	return child && !child->nextSiblingBox();
	}

	RenderBox& RenderMathMLFraction::numerator() const
	{
	ASSERT(isValid());
	return *firstChildBox();
	}

	RenderBox& RenderMathMLFraction::denominator() const
	{
	ASSERT(isValid());
	return *firstChildBox()->nextSiblingBox();
	}

	LayoutUnit RenderMathMLFraction::defaultLineThickness() const
	{
	const auto& primaryFont = style().fontCascade().primaryFont();
	if (const auto* mathData = primaryFont.mathData())
	return LayoutUnit(mathData->getMathConstant(primaryFont, OpenTypeMathData::FractionRuleThickness));
	return ruleThicknessFallback();
	}

	LayoutUnit RenderMathMLFraction::lineThickness() const
	{
	return std::max<LayoutUnit>(toUserUnits(element().lineThickness(), style(), defaultLineThickness()), 0);
	}

	float RenderMathMLFraction::relativeLineThickness() const
	{
	if (LayoutUnit defaultThickness = defaultLineThickness())
	return lineThickness() / defaultThickness;
	return 0;
	}

	RenderMathMLFraction::FractionParameters RenderMathMLFraction::fractionParameters() const
	{
	// See https://mathml-refresh.github.io/mathml-core/#fraction-with-nonzero-line-thickness.

	ASSERT(lineThickness());
	FractionParameters parameters;
	LayoutUnit numeratorGapMin, denominatorGapMin, numeratorMinShiftUp, denominatorMinShiftDown;

	// We try and read constants to draw the fraction from the OpenType MATH and use fallback values otherwise.
	const auto& primaryFont = style().fontCascade().primaryFont();
	const auto* mathData = style().fontCascade().primaryFont().mathData();
	bool display = mathMLStyle().displayStyle();
	if (mathData) {
	numeratorGapMin = mathData->getMathConstant(primaryFont, display ? OpenTypeMathData::FractionNumDisplayStyleGapMin : OpenTypeMathData::FractionNumeratorGapMin);
	denominatorGapMin = mathData->getMathConstant(primaryFont, display ? OpenTypeMathData::FractionDenomDisplayStyleGapMin : OpenTypeMathData::FractionDenominatorGapMin);
	numeratorMinShiftUp = mathData->getMathConstant(primaryFont, display ? OpenTypeMathData::FractionNumeratorDisplayStyleShiftUp : OpenTypeMathData::FractionNumeratorShiftUp);
	denominatorMinShiftDown = mathData->getMathConstant(primaryFont, display ? OpenTypeMathData::FractionDenominatorDisplayStyleShiftDown : OpenTypeMathData::FractionDenominatorShiftDown);
	} else {
	// The MATH table specification suggests default rule thickness or (in displaystyle) 3 times default rule thickness for the gaps.
	numeratorGapMin = display ? 3 * ruleThicknessFallback() : ruleThicknessFallback();
	denominatorGapMin = numeratorGapMin;

	// The MATH table specification does not suggest any values for shifts, so we leave them at zero.
	numeratorMinShiftUp = 0;
	denominatorMinShiftDown = 0;
	}

	// Adjust fraction shifts to satisfy min gaps.
	LayoutUnit numeratorAscent = ascentForChild(numerator());
	LayoutUnit numeratorDescent = numerator().logicalHeight() - numeratorAscent;
	LayoutUnit denominatorAscent = ascentForChild(denominator());
	LayoutUnit thickness = lineThickness();
	parameters.numeratorShiftUp = std::max(numeratorMinShiftUp, mathAxisHeight() + thickness / 2 + numeratorGapMin + numeratorDescent);
	parameters.denominatorShiftDown = std::max(denominatorMinShiftDown, thickness / 2 + denominatorGapMin + denominatorAscent - mathAxisHeight());

	return parameters;
	}

	RenderMathMLFraction::FractionParameters RenderMathMLFraction::stackParameters() const
	{
	// See https://mathml-refresh.github.io/mathml-core/#fraction-with-zero-line-thickness.

	ASSERT(!lineThickness());
	ASSERT(isValid());
	FractionParameters parameters;
	LayoutUnit gapMin;

	// We try and read constants to draw the stack from the OpenType MATH and use fallback values otherwise.
	const auto& primaryFont = style().fontCascade().primaryFont();
	const auto* mathData = style().fontCascade().primaryFont().mathData();
	bool display = mathMLStyle().displayStyle();
	if (mathData) {
	gapMin = mathData->getMathConstant(primaryFont, display ? OpenTypeMathData::StackDisplayStyleGapMin : OpenTypeMathData::StackGapMin);
	parameters.numeratorShiftUp = mathData->getMathConstant(primaryFont, display ? OpenTypeMathData::StackTopDisplayStyleShiftUp : OpenTypeMathData::StackTopShiftUp);
	parameters.denominatorShiftDown = mathData->getMathConstant(primaryFont, display ? OpenTypeMathData::StackBottomDisplayStyleShiftDown : OpenTypeMathData::StackBottomShiftDown);
	} else {
	// We use the values suggested in the MATH table specification.
	gapMin = display ? 7 * ruleThicknessFallback() : 3 * ruleThicknessFallback();

	// The MATH table specification does not suggest any values for shifts, so we leave them at zero.
	parameters.numeratorShiftUp = 0;
	parameters.denominatorShiftDown = 0;
	}

	// Adjust fraction shifts to satisfy min gaps.
	LayoutUnit numeratorAscent = ascentForChild(numerator());
	LayoutUnit numeratorDescent = numerator().logicalHeight() - numeratorAscent;
	LayoutUnit denominatorAscent = ascentForChild(denominator());
	LayoutUnit gap = parameters.numeratorShiftUp - numeratorDescent + parameters.denominatorShiftDown - denominatorAscent;
	if (gap < gapMin) {
	LayoutUnit delta = (gapMin - gap) / 2;
	parameters.numeratorShiftUp += delta;
	parameters.denominatorShiftDown += delta;
	}

	return parameters;
	}

	RenderMathMLOperator* RenderMathMLFraction::unembellishedOperator() const
	{
	if (!isValid() \|\| !is<RenderMathMLBlock>(numerator()))
	return nullptr;

	return downcast<RenderMathMLBlock>(numerator()).unembellishedOperator();
	}

	void RenderMathMLFraction::computePreferredLogicalWidths()
	{
	ASSERT(preferredLogicalWidthsDirty());

	m_minPreferredLogicalWidth = 0;
	m_maxPreferredLogicalWidth = 0;

	if (isValid()) {
	LayoutUnit numeratorWidth = numerator().maxPreferredLogicalWidth();
	LayoutUnit denominatorWidth = denominator().maxPreferredLogicalWidth();
	m_minPreferredLogicalWidth = m_maxPreferredLogicalWidth = std::max(numeratorWidth, denominatorWidth);
	}

	setPreferredLogicalWidthsDirty(false);
	}

	LayoutUnit RenderMathMLFraction::horizontalOffset(RenderBox& child, MathMLFractionElement::FractionAlignment align) const
	{
	switch (align) {
	case MathMLFractionElement::FractionAlignmentRight:
	return LayoutUnit(logicalWidth() - child.logicalWidth());
	case MathMLFractionElement::FractionAlignmentCenter:
	return LayoutUnit((logicalWidth() - child.logicalWidth()) / 2);
	case MathMLFractionElement::FractionAlignmentLeft:
	return 0_lu;
	}

	ASSERT_NOT_REACHED();
	return 0_lu;
	}

	LayoutUnit RenderMathMLFraction::fractionAscent() const
	{
	ASSERT(isValid());

	LayoutUnit numeratorAscent = ascentForChild(numerator());
	if (LayoutUnit thickness = lineThickness())
	return std::max(mathAxisHeight() + thickness / 2, numeratorAscent + fractionParameters().numeratorShiftUp);

	return numeratorAscent + stackParameters().numeratorShiftUp;
	}

	void RenderMathMLFraction::layoutBlock(bool relayoutChildren, LayoutUnit)
	{
	ASSERT(needsLayout());

	if (!relayoutChildren && simplifiedLayout())
	return;

	if (!isValid()) {
	layoutInvalidMarkup(relayoutChildren);
	return;
	}

	numerator().layoutIfNeeded();
	denominator().layoutIfNeeded();

	setLogicalWidth(std::max(numerator().logicalWidth(), denominator().logicalWidth()));

	LayoutUnit verticalOffset; // This is the top of the renderer.
	LayoutPoint numeratorLocation(horizontalOffset(numerator(), element().numeratorAlignment()), verticalOffset);
	numerator().setLocation(numeratorLocation);

	LayoutUnit denominatorAscent = ascentForChild(denominator());
	verticalOffset = fractionAscent();
	FractionParameters parameters = lineThickness() ? fractionParameters() : stackParameters();
	verticalOffset += parameters.denominatorShiftDown - denominatorAscent;

	LayoutPoint denominatorLocation(horizontalOffset(denominator(), element().denominatorAlignment()), verticalOffset);
	denominator().setLocation(denominatorLocation);

	verticalOffset += denominator().logicalHeight(); // This is the bottom of our renderer.
	setLogicalHeight(verticalOffset);

	layoutPositionedObjects(relayoutChildren);

	updateScrollInfoAfterLayout();

	clearNeedsLayout();
	}

	void RenderMathMLFraction::paint(PaintInfo& info, const LayoutPoint& paintOffset)
	{
	RenderMathMLBlock::paint(info, paintOffset);
	LayoutUnit thickness = lineThickness();
	if (info.context().paintingDisabled() \|\| info.phase != PaintPhase::Foreground \|\| style().visibility() != Visibility::Visible \|\| !isValid() \|\| !thickness)
	return;

	IntPoint adjustedPaintOffset = roundedIntPoint(paintOffset + location() + LayoutPoint(0_lu, fractionAscent() - mathAxisHeight()));

	GraphicsContextStateSaver stateSaver(info.context());

	info.context().setStrokeThickness(thickness);
	info.context().setStrokeStyle(SolidStroke);
	info.context().setStrokeColor(style().visitedDependentColorWithColorFilter(CSSPropertyColor));
	info.context().drawLine(adjustedPaintOffset, roundedIntPoint(LayoutPoint(adjustedPaintOffset.x() + logicalWidth(), LayoutUnit(adjustedPaintOffset.y()))));
	}

	Optional<int> RenderMathMLFraction::firstLineBaseline() const
	{
	if (isValid())
	return Optional<int>(std::lround(static_cast<float>(fractionAscent())));
	return RenderMathMLBlock::firstLineBaseline();
	}

	}

	#endif // ENABLE(MATHML)