C++ RenderBoxModelObject::parent方法代码示例

void RenderLineBoxList::dirtyLinesFromChangedChild(RenderBoxModelObject& container, RenderObject& child)
{
    ASSERT(is<RenderInline>(container) || is<RenderBlockFlow>(container));
    if (!container.parent() || (is<RenderBlockFlow>(container) && container.selfNeedsLayout()))
        return;

    RenderInline* inlineContainer = is<RenderInline>(container) ? &downcast<RenderInline>(container) : nullptr;
    InlineBox* firstBox = inlineContainer ? inlineContainer->firstLineBoxIncludingCulling() : firstLineBox();

    // If we have no first line box, then just bail early.
    if (!firstBox) {
        // For an empty inline, propagate the check up to our parent, unless the parent is already dirty.
        if (container.isInline() && !container.ancestorLineBoxDirty()) {
            container.parent()->dirtyLinesFromChangedChild(container);
            container.setAncestorLineBoxDirty(); // Mark the container to avoid dirtying the same lines again across multiple destroy() calls of the same subtree.
        }
        return;
    }

    // Try to figure out which line box we belong in. First try to find a previous
    // line box by examining our siblings. If we didn't find a line box, then use our
    // parent's first line box.
    RootInlineBox* box = nullptr;
    RenderObject* current;
    for (current = child.previousSibling(); current; current = current->previousSibling()) {
        if (current->isFloatingOrOutOfFlowPositioned())
            continue;

        if (current->isReplaced()) {
            if (auto wrapper = downcast<RenderBox>(*current).inlineBoxWrapper())
                box = &wrapper->root();
        } if (is<RenderLineBreak>(*current)) {
            if (auto wrapper = downcast<RenderLineBreak>(*current).inlineBoxWrapper())
                box = &wrapper->root();
        } else if (is<RenderText>(*current)) {
            if (InlineTextBox* textBox = downcast<RenderText>(*current).lastTextBox())
                box = &textBox->root();
        } else if (is<RenderInline>(*current)) {
            InlineBox* lastSiblingBox = downcast<RenderInline>(*current).lastLineBoxIncludingCulling();
            if (lastSiblingBox)
                box = &lastSiblingBox->root();
        }

        if (box)
            break;
    }
    if (!box) {
        if (inlineContainer && !inlineContainer->alwaysCreateLineBoxes()) {
            // https://bugs.webkit.org/show_bug.cgi?id=60778
            // We may have just removed a <br> with no line box that was our first child. In this case
            // we won't find a previous sibling, but firstBox can be pointing to a following sibling.
            // This isn't good enough, since we won't locate the root line box that encloses the removed
            // <br>. We have to just over-invalidate a bit and go up to our parent.
            if (!inlineContainer->ancestorLineBoxDirty()) {
                inlineContainer->parent()->dirtyLinesFromChangedChild(*inlineContainer);
                inlineContainer->setAncestorLineBoxDirty(); // Mark the container to avoid dirtying the same lines again across multiple destroy() calls of the same subtree.
            }
            return;
        }
        box = &firstBox->root();
    }

    // If we found a line box, then dirty it.
    if (box) {
        box->markDirty();

        // Dirty the adjacent lines that might be affected.
        // NOTE: we dirty the previous line because RootInlineBox objects cache
        // the address of the first object on the next line after a BR, which we may be
        // invalidating here. For more info, see how RenderBlock::layoutInlineChildren
        // calls setLineBreakInfo with the result of findNextLineBreak. findNextLineBreak,
        // despite the name, actually returns the first RenderObject after the BR.
        // <rdar://problem/3849947> "Typing after pasting line does not appear until after window resize."
        if (RootInlineBox* prevBox = box->prevRootBox())
            prevBox->markDirty();

        // FIXME: We shouldn't need to always dirty the next line. This is only strictly 
        // necessary some of the time, in situations involving BRs.
        if (RootInlineBox* nextBox = box->nextRootBox()) {
            nextBox->markDirty();
            // Dedicated linebox for floats may be added as the last rootbox. If this occurs with BRs inside inlines that propagte their lineboxes to
            // the parent flow, we need to invalidate it explicitly.
            // FIXME: We should be able to figure out the actual "changed child" even when we are calling through empty inlines recursively.
            if (is<RenderInline>(child) && !downcast<RenderInline>(child).firstLineBoxIncludingCulling()) {
                auto* lastRootBox = nextBox->blockFlow().lastRootBox();
                if (lastRootBox->isTrailingFloatsRootInlineBox() && !lastRootBox->isDirty())
                    lastRootBox->markDirty();
            }
        }
    }
}

void RootInlineBox::ascentAndDescentForBox(InlineBox* box, GlyphOverflowAndFallbackFontsMap& textBoxDataMap, int& ascent, int& descent,
                                           bool& affectsAscent, bool& affectsDescent) const
{
    bool ascentDescentSet = false;

    // Replaced boxes will return 0 for the line-height if line-box-contain says they are
    // not to be included.
    if (box->renderer().isReplaced()) {
        if (lineStyle().lineBoxContain() & LineBoxContainReplaced) {
            ascent = box->baselinePosition(baselineType());
            descent = box->lineHeight() - ascent;
            
            // Replaced elements always affect both the ascent and descent.
            affectsAscent = true;
            affectsDescent = true;
        }
        return;
    }

    Vector<const SimpleFontData*>* usedFonts = 0;
    GlyphOverflow* glyphOverflow = 0;
    if (box->isInlineTextBox()) {
        GlyphOverflowAndFallbackFontsMap::iterator it = textBoxDataMap.find(toInlineTextBox(box));
        usedFonts = it == textBoxDataMap.end() ? 0 : &it->value.first;
        glyphOverflow = it == textBoxDataMap.end() ? 0 : &it->value.second;
    }
        
    bool includeLeading = includeLeadingForBox(box);
    bool includeFont = includeFontForBox(box);
    
    bool setUsedFont = false;
    bool setUsedFontWithLeading = false;

    const RenderStyle& boxLineStyle = box->lineStyle();
#if PLATFORM(IOS)
    if (usedFonts && !usedFonts->isEmpty() && (includeFont || (boxLineStyle.lineHeight().isNegative() && includeLeading)) && !box->renderer().document().settings()->alwaysUseBaselineOfPrimaryFont()) {
#else
    if (usedFonts && !usedFonts->isEmpty() && (includeFont || (boxLineStyle.lineHeight().isNegative() && includeLeading))) {
#endif
        usedFonts->append(boxLineStyle.font().primaryFont());
        for (size_t i = 0; i < usedFonts->size(); ++i) {
            const FontMetrics& fontMetrics = usedFonts->at(i)->fontMetrics();
            int usedFontAscent = fontMetrics.ascent(baselineType());
            int usedFontDescent = fontMetrics.descent(baselineType());
            int halfLeading = (fontMetrics.lineSpacing() - fontMetrics.height()) / 2;
            int usedFontAscentAndLeading = usedFontAscent + halfLeading;
            int usedFontDescentAndLeading = fontMetrics.lineSpacing() - usedFontAscentAndLeading;
            if (includeFont) {
                setAscentAndDescent(ascent, descent, usedFontAscent, usedFontDescent, ascentDescentSet);
                setUsedFont = true;
            }
            if (includeLeading) {
                setAscentAndDescent(ascent, descent, usedFontAscentAndLeading, usedFontDescentAndLeading, ascentDescentSet);
                setUsedFontWithLeading = true;
            }
            if (!affectsAscent)
                affectsAscent = usedFontAscent - box->logicalTop() > 0;
            if (!affectsDescent)
                affectsDescent = usedFontDescent + box->logicalTop() > 0;
        }
    }

    // If leading is included for the box, then we compute that box.
    if (includeLeading && !setUsedFontWithLeading) {
        int ascentWithLeading = box->baselinePosition(baselineType());
        int descentWithLeading = box->lineHeight() - ascentWithLeading;
        setAscentAndDescent(ascent, descent, ascentWithLeading, descentWithLeading, ascentDescentSet);
        
        // 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. Descent is similar. If any part of our font box is below
        // the root box's baseline, then we contribute to the maxDescent value.
        affectsAscent = ascentWithLeading - box->logicalTop() > 0;
        affectsDescent = descentWithLeading + box->logicalTop() > 0; 
    }
    
    if (includeFontForBox(box) && !setUsedFont) {
        int fontAscent = boxLineStyle.fontMetrics().ascent(baselineType());
        int fontDescent = boxLineStyle.fontMetrics().descent(baselineType());
        setAscentAndDescent(ascent, descent, fontAscent, fontDescent, ascentDescentSet);
        affectsAscent = fontAscent - box->logicalTop() > 0;
        affectsDescent = fontDescent + box->logicalTop() > 0; 
    }

    if (includeGlyphsForBox(box) && glyphOverflow && glyphOverflow->computeBounds) {
        setAscentAndDescent(ascent, descent, glyphOverflow->top, glyphOverflow->bottom, ascentDescentSet);
        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);
//.........这里部分代码省略.........