RenderMathMLFraction.cpp [plain text]
#include "config.h"
#if ENABLE(MATHML)
#include "RenderMathMLFraction.h"
#include "GraphicsContext.h"
#include "MathMLNames.h"
#include "PaintInfo.h"
#include "RenderText.h"
namespace WebCore {
using namespace MathMLNames;
static const float gHorizontalPad = 0.2f;
static const float gLineThin = 0.33f;
static const float gLineMedium = 1.f;
static const float gLineThick = 3.f;
static const float gFractionBarWidth = 0.05f;
static const float gDenominatorPad = 0.1f;
RenderMathMLFraction::RenderMathMLFraction(Element* element)
: RenderMathMLBlock(element)
, m_lineThickness(gLineMedium)
{
setChildrenInline(false);
}
void RenderMathMLFraction::updateFromElement()
{
if (isEmpty())
return;
Element* fraction = static_cast<Element*>(node());
RenderObject* numeratorWrapper = firstChild();
String nalign = fraction->getAttribute(MathMLNames::numalignAttr);
if (equalIgnoringCase(nalign, "left"))
numeratorWrapper->style()->setTextAlign(LEFT);
else if (equalIgnoringCase(nalign, "right"))
numeratorWrapper->style()->setTextAlign(RIGHT);
else
numeratorWrapper->style()->setTextAlign(CENTER);
RenderObject* denominatorWrapper = numeratorWrapper->nextSibling();
if (!denominatorWrapper)
return;
String dalign = fraction->getAttribute(MathMLNames::denomalignAttr);
if (equalIgnoringCase(dalign, "left"))
denominatorWrapper->style()->setTextAlign(LEFT);
else if (equalIgnoringCase(dalign, "right"))
denominatorWrapper->style()->setTextAlign(RIGHT);
else
denominatorWrapper->style()->setTextAlign(CENTER);
String thickness = fraction->getAttribute(MathMLNames::linethicknessAttr);
m_lineThickness = gLineMedium;
if (equalIgnoringCase(thickness, "thin"))
m_lineThickness = gLineThin;
else if (equalIgnoringCase(thickness, "medium"))
m_lineThickness = gLineMedium;
else if (equalIgnoringCase(thickness, "thick"))
m_lineThickness = gLineThick;
else if (equalIgnoringCase(thickness, "0"))
m_lineThickness = 0;
lastChild()->style()->setPaddingTop(Length(static_cast<int>(m_lineThickness + style()->fontSize() * gDenominatorPad), Fixed));
}
void RenderMathMLFraction::addChild(RenderObject* child, RenderObject* beforeChild)
{
RenderBlock* row = createAlmostAnonymousBlock();
row->style()->setTextAlign(CENTER);
Length pad(static_cast<int>(style()->fontSize() * gHorizontalPad), Fixed);
row->style()->setPaddingLeft(pad);
row->style()->setPaddingRight(pad);
bool isNumerator = isEmpty();
if (!isNumerator)
row->style()->setPaddingTop(Length(2, Fixed));
RenderBlock::addChild(row, beforeChild);
row->addChild(child);
updateFromElement();
}
RenderMathMLOperator* RenderMathMLFraction::unembellishedOperator()
{
RenderObject* numeratorWrapper = firstChild();
if (!numeratorWrapper)
return 0;
RenderObject* numerator = numeratorWrapper->firstChild();
if (!numerator || !numerator->isRenderMathMLBlock())
return 0;
return toRenderMathMLBlock(numerator)->unembellishedOperator();
}
void RenderMathMLFraction::layout()
{
updateFromElement();
if (lastChild() && lastChild()->isRenderBlock())
m_lineThickness *= ceilf(gFractionBarWidth * style()->fontSize());
RenderBlock::layout();
}
void RenderMathMLFraction::paint(PaintInfo& info, const LayoutPoint& paintOffset)
{
RenderMathMLBlock::paint(info, paintOffset);
if (info.context->paintingDisabled() || info.phase != PaintPhaseForeground)
return;
if (!firstChild() ||!m_lineThickness)
return;
int verticalOffset = 0;
if (firstChild()->isRenderMathMLBlock()) {
int adjustForThickness = m_lineThickness > 1 ? int(m_lineThickness / 2) : 1;
if (int(m_lineThickness) % 2 == 1)
adjustForThickness++;
RenderMathMLBlock* numerator = toRenderMathMLBlock(firstChild());
if (numerator->isRenderMathMLRow())
verticalOffset = numerator->pixelSnappedOffsetHeight() + adjustForThickness;
else
verticalOffset = numerator->pixelSnappedOffsetHeight();
}
IntPoint adjustedPaintOffset = roundedIntPoint(paintOffset + location());
adjustedPaintOffset.setY(adjustedPaintOffset.y() + verticalOffset);
GraphicsContextStateSaver stateSaver(*info.context);
info.context->setStrokeThickness(m_lineThickness);
info.context->setStrokeStyle(SolidStroke);
info.context->setStrokeColor(style()->visitedDependentColor(CSSPropertyColor), ColorSpaceSRGB);
info.context->drawLine(adjustedPaintOffset, IntPoint(adjustedPaintOffset.x() + pixelSnappedOffsetWidth(), adjustedPaintOffset.y()));
}
LayoutUnit RenderMathMLFraction::baselinePosition(FontBaseline, bool firstLine, LineDirectionMode lineDirection, LinePositionMode linePositionMode) const
{
if (firstChild() && firstChild()->isRenderMathMLBlock()) {
RenderMathMLBlock* numeratorWrapper = toRenderMathMLBlock(firstChild());
RenderStyle* refStyle = style();
if (previousSibling())
refStyle = previousSibling()->style();
else if (nextSibling())
refStyle = nextSibling()->style();
int shift = int(ceil((refStyle->fontMetrics().xHeight() + 1) / 2));
return numeratorWrapper->pixelSnappedOffsetHeight() + shift;
}
return RenderBlock::baselinePosition(AlphabeticBaseline, firstLine, lineDirection, linePositionMode);
}
}
#endif // ENABLE(MATHML)