C++ RenderBoxModelObject::style方法代码示例

void RenderMathMLSquareRoot::layout()
{
    int maxHeight = 0;
    
    RenderObject* current = firstChild();
    while (current) {
        if (current->isBoxModelObject()) {
            RenderBoxModelObject* box = toRenderBoxModelObject(current);
            
            if (box->pixelSnappedOffsetHeight() > maxHeight)
                maxHeight = box->pixelSnappedOffsetHeight();
            
            box->style()->setVerticalAlign(BASELINE);
        }
        current = current->nextSibling();
    }
    
    if (!maxHeight)
        maxHeight = style()->fontSize();

    
    if (maxHeight > static_cast<int>(gThresholdBaseHeight * style()->fontSize()))
        style()->setPaddingBottom(Length(static_cast<int>(gRootBottomPadding * style()->fontSize()), Fixed));

    
    RenderBlock::layout();
}

void RenderMathMLRoot::layout()
{
    RenderBlock::layout();

    if (!firstChild() || !lastChild())
        return;

    int baseHeight = toRenderBoxModelObject(lastChild())->pixelSnappedOffsetHeight();
    if (!baseHeight)
        baseHeight = style()->fontSize();
    
    RenderObject* base = lastChild()->firstChild();
    if (base)
        base->style()->setVerticalAlign(BASELINE); // FIXME: Can this style be modified?
    
    // Base height above which the shape of the root changes
    int thresholdHeight = static_cast<int>(gThresholdBaseHeightEms * style()->fontSize());
    int overbarLeftPointShift = 0;
    
    // FIXME: Can style() and indexBox->style() be modified (4 times below)?
    if (baseHeight > thresholdHeight && thresholdHeight) {
        float shift = (baseHeight - thresholdHeight) / static_cast<float>(thresholdHeight);
        if (shift > 1.)
            shift = 1.0f;
        int frontWidth = static_cast<int>(style()->fontSize() * gFrontWidthEms);
        overbarLeftPointShift = static_cast<int>(gRadicalBottomPointXFront * frontWidth * shift);
        
        style()->setPaddingBottom(Length(static_cast<int>(gBigRootBottomPaddingEms * style()->fontSize()), Fixed));
    }
    
    // Positioning of the index
    RenderObject* possibleIndex = firstChild()->firstChild();
    while (possibleIndex && !possibleIndex->isBoxModelObject())
        possibleIndex = possibleIndex->nextSibling();
    RenderBoxModelObject* indexBox = toRenderBoxModelObject(possibleIndex);
    if (!indexBox)
        return;
    
    int shiftForIndex = indexBox->pixelSnappedOffsetWidth() + overbarLeftPointShift;
    int partDipHeight = static_cast<int>((1 - gRadicalDipLeftPointYPos) * baseHeight);
    int rootExtraTop = partDipHeight + style()->paddingBottom().value() + indexBox->pixelSnappedOffsetHeight()
        - (baseHeight + static_cast<int>(gRootPaddingEms * style()->fontSize()));
    
    style()->setPaddingLeft(Length(shiftForIndex, Fixed));
    if (rootExtraTop > 0)
        style()->setPaddingTop(Length(rootExtraTop + static_cast<int>(gRootPaddingEms * style()->fontSize()), Fixed));
    
    setNeedsLayout(true);
    setPreferredLogicalWidthsDirty(true, MarkOnlyThis); // FIXME: Can this really be right?
    RenderBlock::layout();

    indexBox->style()->setBottom(Length(partDipHeight + style()->paddingBottom().value(), Fixed));

    // Now that we've potentially changed its position, we need layout the index again.
    indexBox->setNeedsLayout(true);
    indexBox->layout();
}

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();
    
    // Base height above which the shape of the root changes
    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));
    }
    
    // Positioning of the index
    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));

    // Now that we've potentially changed its position, we need layout the index again.
    indexBox->setNeedsLayout(true);
    indexBox->layout();
}

static inline RenderBoxModelObject& findRendererDefininingTextDecoration(InlineFlowBox* parentBox)
{
    // Lookup first render object in parent hierarchy which has text-decoration set.
    RenderBoxModelObject* renderer = nullptr;
    while (parentBox) {
        renderer = &parentBox->renderer();

        if (renderer->style()->textDecoration() != TextDecorationNone)
            break;

        parentBox = parentBox->parent();
    }

    ASSERT(renderer);
    return *renderer;
}

void SVGInlineTextBox::paintDecorationWithStyle(GraphicsContext* context, TextDecoration decoration, const SVGTextFragment& fragment, RenderBoxModelObject& decorationRenderer)
{
    ASSERT(!m_paintingResource);
    ASSERT(m_paintingResourceMode != ApplyToDefaultMode);

    RenderStyle* decorationStyle = decorationRenderer.style();
    ASSERT(decorationStyle);

    float scalingFactor = 1;
    Font scaledFont;
    RenderSVGInlineText::computeNewScaledFontForStyle(&decorationRenderer, decorationStyle, scalingFactor, scaledFont);
    ASSERT(scalingFactor);

    // The initial y value refers to overline position.
    float thickness = thicknessForDecoration(decoration, scaledFont);

    if (fragment.width <= 0 && thickness <= 0)
        return;

    FloatPoint decorationOrigin(fragment.x, fragment.y);
    float width = fragment.width;
    const FontMetrics& scaledFontMetrics = scaledFont.fontMetrics();

    GraphicsContextStateSaver stateSaver(*context);
    if (scalingFactor != 1) {
        width *= scalingFactor;
        decorationOrigin.scale(scalingFactor, scalingFactor);
        context->scale(FloatSize(1 / scalingFactor, 1 / scalingFactor));
    }

    decorationOrigin.move(0, -scaledFontMetrics.floatAscent() + positionOffsetForDecoration(decoration, scaledFontMetrics, thickness));

    Path path;
    path.addRect(FloatRect(decorationOrigin, FloatSize(width, thickness)));

    if (acquirePaintingResource(context, scalingFactor, decorationRenderer, decorationStyle))
        releasePaintingResource(context, &path);
}

//.........这里部分代码省略.........
        affectsAscent = glyphOverflow->top - box->logicalTop() > 0;
        affectsDescent = glyphOverflow->bottom + box->logicalTop() > 0; 
        glyphOverflow->top = std::min(glyphOverflow->top, std::max(0, glyphOverflow->top - boxLineStyle.fontMetrics().ascent(baselineType())));
        glyphOverflow->bottom = std::min(glyphOverflow->bottom, std::max(0, glyphOverflow->bottom - boxLineStyle.fontMetrics().descent(baselineType())));
    }

    if (includeMarginForBox(box)) {
        LayoutUnit ascentWithMargin = boxLineStyle.fontMetrics().ascent(baselineType());
        LayoutUnit descentWithMargin = boxLineStyle.fontMetrics().descent(baselineType());
        if (box->parent() && !box->renderer().isTextOrLineBreak()) {
            ascentWithMargin += box->boxModelObject()->borderAndPaddingBefore() + box->boxModelObject()->marginBefore();
            descentWithMargin += box->boxModelObject()->borderAndPaddingAfter() + box->boxModelObject()->marginAfter();
        }
        setAscentAndDescent(ascent, descent, ascentWithMargin, descentWithMargin, ascentDescentSet);
        
        // Treat like a replaced element, since we're using the margin box.
        affectsAscent = true;
        affectsDescent = true;
    }
}

LayoutUnit RootInlineBox::verticalPositionForBox(InlineBox* box, VerticalPositionCache& verticalPositionCache)
{
    if (box->renderer().isTextOrLineBreak())
        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.
    bool firstLine = isFirstLine();
    if (firstLine && !renderer->document().styleSheetCollection().usesFirstLineRules())
        firstLine = false;

    // Check the cache.
    bool isRenderInline = renderer->isRenderInline();
    if (isRenderInline && !firstLine) {
        LayoutUnit verticalPosition = verticalPositionCache.get(renderer, baselineType());
        if (verticalPosition != PositionUndefined)
            return verticalPosition;
    }

    LayoutUnit verticalPosition = 0;
    EVerticalAlign verticalAlign = renderer->style().verticalAlign();
    if (verticalAlign == TOP || verticalAlign == BOTTOM)
        return 0;
   
    RenderElement* parent = renderer->parent();
    if (parent->isRenderInline() && parent->style().verticalAlign() != TOP && parent->style().verticalAlign() != BOTTOM)
        verticalPosition = box->parent()->logicalTop();
    
    if (verticalAlign != BASELINE) {
        const RenderStyle& parentLineStyle = firstLine ? parent->firstLineStyle() : parent->style();
        const Font& font = parentLineStyle.font();
        const FontMetrics& fontMetrics = font.fontMetrics();
        int fontSize = font.pixelSize();

        LineDirectionMode lineDirection = parent->isHorizontalWritingMode() ? HorizontalLine : VerticalLine;

        if (verticalAlign == SUB)
            verticalPosition += fontSize / 5 + 1;
        else if (verticalAlign == SUPER)
            verticalPosition -= fontSize / 3 + 1;
        else if (verticalAlign == TEXT_TOP)