RenderMathMLRoot.cpp [plain text]
#include "config.h"
#if ENABLE(MATHML)
#include "RenderMathMLRoot.h"
#include "GraphicsContext.h"
#include "MathMLNames.h"
#include "PaintInfo.h"
namespace WebCore {
using namespace MathMLNames;
const int gRadicalLeftMargin = 3;
const int gRadicalBasePad = 3;
const float gThresholdBaseHeight = 1.5f;
const float gRadicalWidth = 0.75f;
const float gRadicalBottomPointXPos= 0.5f;
const float gRadicalTopLeftPointXPos = 0.8f;
const float gRadicalTopLeftPointYPos = 0.625f;
const float gRadicalLeftEndYShift = 0.05f;
const float gRootPadding = 0.2f;
const float gRootBottomPadding = 0.2f;
const float gRadicalLineThickness = 0.02f;
const float gRadicalThickLineThickness = 0.1f;
RenderMathMLRoot::RenderMathMLRoot(Node *expression)
: RenderMathMLBlock(expression)
{
}
void RenderMathMLRoot::addChild(RenderObject* child, RenderObject* )
{
if (isEmpty()) {
RenderBlock* block = new (renderArena()) RenderBlock(node());
RefPtr<RenderStyle> indexStyle = makeBlockStyle();
indexStyle->setDisplay(INLINE_BLOCK);
block->setStyle(indexStyle.release());
RenderBlock::addChild(block);
block = new (renderArena()) RenderBlock(node());
RefPtr<RenderStyle> baseStyle = makeBlockStyle();
baseStyle->setDisplay(INLINE_BLOCK);
baseStyle->setPaddingLeft(Length(5 * gRadicalWidth , Percent));
block->setStyle(baseStyle.release());
RenderBlock::addChild(block);
block->addChild(child);
} else {
firstChild()->addChild(child);
}
}
void RenderMathMLRoot::paint(PaintInfo& info, int tx, int ty)
{
RenderMathMLBlock::paint(info , tx , ty);
if (info.context->paintingDisabled())
return;
if (!firstChild() || !lastChild())
return;
tx += x();
ty += y();
RenderBoxModelObject* indexBox = toRenderBoxModelObject(lastChild());
int maxHeight = indexBox->offsetHeight();
if (!maxHeight)
maxHeight = style()->fontSize();
int width = indexBox->offsetWidth();
int indexWidth = 0;
RenderObject* current = firstChild();
while (current != lastChild()) {
if (current->isBoxModelObject()) {
RenderBoxModelObject* box = toRenderBoxModelObject(current);
indexWidth += box->offsetWidth();
}
current = current->nextSibling();
}
int frontWidth = static_cast<int>(style()->fontSize() * gRadicalWidth);
int topStartShift = 0;
int thresholdHeight = static_cast<int>(gThresholdBaseHeight * style()->fontSize());
if (maxHeight > thresholdHeight && thresholdHeight) {
float shift = (maxHeight - thresholdHeight) / static_cast<float>(thresholdHeight);
if (shift > 1.)
shift = 1.0f;
topStartShift = static_cast<int>(gRadicalBottomPointXPos * frontWidth * shift);
}
width += topStartShift;
int rootPad = static_cast<int>(gRootPadding * style()->fontSize());
int start = tx + indexWidth + gRadicalLeftMargin + style()->paddingLeft().value() - rootPad;
ty += style()->paddingTop().value() - rootPad;
FloatPoint topStart(start - topStartShift, ty);
FloatPoint bottomLeft(start - gRadicalBottomPointXPos * frontWidth , ty + maxHeight + gRadicalBasePad);
FloatPoint topLeft(start - gRadicalTopLeftPointXPos * frontWidth , ty + gRadicalTopLeftPointYPos * maxHeight);
FloatPoint leftEnd(start - frontWidth , topLeft.y() + gRadicalLeftEndYShift * style()->fontSize());
GraphicsContextStateSaver stateSaver(*info.context);
info.context->setStrokeThickness(gRadicalLineThickness * style()->fontSize());
info.context->setStrokeStyle(SolidStroke);
info.context->setStrokeColor(style()->visitedDependentColor(CSSPropertyColor), ColorSpaceDeviceRGB);
info.context->setLineJoin(MiterJoin);
info.context->setMiterLimit(style()->fontSize());
Path root;
root.moveTo(FloatPoint(topStart.x() + width, ty));
root.addLineTo(topStart);
root.addLineTo(bottomLeft);
root.addLineTo(topLeft);
root.addLineTo(leftEnd);
info.context->strokePath(root);
GraphicsContextStateSaver maskStateSaver(*info.context);
Path mask;
mask.moveTo(topStart);
mask.addLineTo(bottomLeft);
mask.addLineTo(topLeft);
mask.addLineTo(FloatPoint(2 * topLeft.x() - leftEnd.x(), 2 * topLeft.y() - leftEnd.y()));
info.context->clip(mask);
info.context->setStrokeThickness(gRadicalThickLineThickness * style()->fontSize());
info.context->setLineCap(SquareCap);
Path line;
line.moveTo(bottomLeft);
line.addLineTo(topLeft);
info.context->strokePath(line);
}
void RenderMathMLRoot::layout()
{
RenderBlock::layout();
if (!firstChild() || !lastChild())
return;
int maxHeight = toRenderBoxModelObject(lastChild())->offsetHeight();
RenderObject* current = lastChild()->firstChild();
if (current)
current->style()->setVerticalAlign(BASELINE);
if (!maxHeight)
maxHeight = style()->fontSize();
int thresholdHeight = static_cast<int>(gThresholdBaseHeight * style()->fontSize());
int topStartShift = 0;
if (maxHeight > thresholdHeight && thresholdHeight) {
float shift = (maxHeight - thresholdHeight) / static_cast<float>(thresholdHeight);
if (shift > 1.)
shift = 1.0f;
int frontWidth = static_cast<int>(style()->fontSize() * gRadicalWidth);
topStartShift = static_cast<int>(gRadicalBottomPointXPos * frontWidth * shift);
style()->setPaddingBottom(Length(static_cast<int>(gRootBottomPadding * style()->fontSize()), Fixed));
}
RenderObject* possibleIndex = firstChild()->firstChild();
while (possibleIndex && !possibleIndex->isBoxModelObject())
possibleIndex = possibleIndex->nextSibling();
RenderBoxModelObject* indexBox = toRenderBoxModelObject(possibleIndex);
if (!indexBox)
return;
int indexShift = indexBox->offsetWidth() + topStartShift;
int radicalHeight = static_cast<int>((1 - gRadicalTopLeftPointYPos) * maxHeight);
int rootMarginTop = radicalHeight + style()->paddingBottom().value() + indexBox->offsetHeight() - (maxHeight + static_cast<int>(gRootPadding * style()->fontSize()));
style()->setPaddingLeft(Length(indexShift, Fixed));
if (rootMarginTop > 0)
style()->setPaddingTop(Length(rootMarginTop + static_cast<int>(gRootPadding * style()->fontSize()), Fixed));
setNeedsLayout(true);
setPreferredLogicalWidthsDirty(true, false);
RenderBlock::layout();
indexBox->style()->setBottom(Length(radicalHeight + style()->paddingBottom().value(), Fixed));
indexBox->setNeedsLayout(true);
indexBox->layout();
}
}
#endif // ENABLE(MATHML)