C++ documentBeingDestroyed函数代码示例

void RenderSVGText::subtreeChildWillBeRemoved(RenderObject* child, Vector<SVGTextLayoutAttributes*, 2>& affectedAttributes)
{
    ASSERT(child);
    if (!shouldHandleSubtreeMutations())
        return;

    checkLayoutAttributesConsistency(this, m_layoutAttributes);

    // The positioning elements cache depends on the size of each text renderer in the
    // subtree. If this changes, clear the cache. It's going to be rebuilt below.
    m_layoutAttributesBuilder.clearTextPositioningElements();
    if (m_layoutAttributes.isEmpty() || !child->isSVGInlineText())
        return;

    // This logic requires that the 'text' child is still inserted in the tree.
    auto& text = downcast<RenderSVGInlineText>(*child);
    bool stopAfterNext = false;
    SVGTextLayoutAttributes* previous = nullptr;
    SVGTextLayoutAttributes* next = nullptr;
    if (!documentBeingDestroyed())
        findPreviousAndNextAttributes(*this, &text, stopAfterNext, previous, next);

    if (previous)
        affectedAttributes.append(previous);
    if (next)
        affectedAttributes.append(next);

    bool removed = m_layoutAttributes.removeFirst(text.layoutAttributes());
    ASSERT_UNUSED(removed, removed);
}

void RenderSVGText::subtreeChildWillBeRemoved(RenderObject* child, Vector<SVGTextLayoutAttributes*, 2>& affectedAttributes)
{
    ASSERT(child);
    if (!shouldHandleSubtreeMutations())
        return;

    checkLayoutAttributesConsistency(this, m_layoutAttributes);

    // The positioning elements cache depends on the size of each text renderer in the
    // subtree. If this changes, clear the cache. It's going to be rebuilt below.
    m_layoutAttributesBuilder.clearTextPositioningElements();
    if (m_layoutAttributes.isEmpty() || !child->isSVGInlineText())
        return;

    // This logic requires that the 'text' child is still inserted in the tree.
    RenderSVGInlineText* text = toRenderSVGInlineText(child);
    SVGTextLayoutAttributes* previous = 0;
    SVGTextLayoutAttributes* next = 0;
    if (!documentBeingDestroyed())
        findPreviousAndNextAttributes(this, text, previous, next);

    if (previous)
        affectedAttributes.append(previous);
    if (next)
        affectedAttributes.append(next);

    size_t position = m_layoutAttributes.find(text->layoutAttributes());
    ASSERT(position != kNotFound);
    m_layoutAttributes.remove(position);
}

void LayoutCounter::invalidate()
{
    m_counterNode->removeLayoutObject(this);
    ASSERT(!m_counterNode);
    if (documentBeingDestroyed())
        return;
    setNeedsLayoutAndPrefWidthsRecalcAndFullPaintInvalidation(LayoutInvalidationReason::CountersChanged);
}

void RenderCounter::invalidate()
{
    m_counterNode->removeRenderer(this);
    ASSERT(!m_counterNode);
    if (documentBeingDestroyed())
        return;
    setNeedsLayoutAndPrefWidthsRecalc();
}

void RenderSVGInlineText::destroy()
{
    if (!documentBeingDestroyed()) {
        setNeedsLayoutAndPrefWidthsRecalc();
        repaint();
    }
    RenderText::destroy();
}

void RenderImage::imageChanged(WrappedImagePtr newImage, const IntRect* rect)
{
    if (documentBeingDestroyed())
        return;

    if (!m_imageResource)
        return;

    if (newImage != m_imageResource->imagePtr())
        return;

    // Per the spec, we let the server-sent header override srcset/other sources of dpr.
    // https://github.com/igrigorik/http-client-hints/blob/master/draft-grigorik-http-client-hints-01.txt#L255
    if (m_imageResource->cachedImage() && m_imageResource->cachedImage()->hasDevicePixelRatioHeaderValue())
        m_imageDevicePixelRatio = 1 / m_imageResource->cachedImage()->devicePixelRatioHeaderValue();

    // If the RenderImage was just created we don't have style() or a parent()
    // yet so all we can do is update our intrinsic size. Once we're inserted
    // the resulting layout will do the rest of the work.
    if (!parent()) {
        updateIntrinsicSizeIfNeeded(m_imageResource->intrinsicSize());
        return;
    }

    RenderReplaced::imageChanged(newImage, rect);

    ASSERT(isRooted());

    LayoutSize oldIntrinsicSize = intrinsicSize();
    LayoutSize newIntrinsicSize = m_imageResource->intrinsicSize();
    updateIntrinsicSizeIfNeeded(newIntrinsicSize);

    bool imageSourceHasChangedSize = oldIntrinsicSize != newIntrinsicSize;
    if (imageSourceHasChangedSize)
        setPreferredLogicalWidthsDirty();

    // If the actual area occupied by the image has changed and it is not constrained by style then a layout is required.
    bool imageSizeIsConstrained = style()->logicalWidth().isSpecified() && style()->logicalHeight().isSpecified();

    // FIXME: We only need to recompute the containing block's preferred size if the containing block's size
    // depends on the image's size (i.e., the container uses shrink-to-fit sizing).
    // There's no easy way to detect that shrink-to-fit is needed, always force a layout.
    bool containingBlockNeedsToRecomputePreferredSize = style()->logicalWidth().isPercent() || style()->logicalMaxWidth().isPercent()  || style()->logicalMinWidth().isPercent();

    if (imageSourceHasChangedSize && (!imageSizeIsConstrained || containingBlockNeedsToRecomputePreferredSize)) {
        setNeedsLayout();
        return;
    }

    // The image hasn't changed in size or its style constrains its size, so a paint invalidation will suffice.
    if (everHadLayout() && !selfNeedsLayout()) {
        // The inner content rectangle is calculated during layout, but may need an update now
        // (unless the box has already been scheduled for layout). In order to calculate it, we
        // may need values from the containing block, though, so make sure that we're not too
        // early. It may be that layout hasn't even taken place once yet.
        updateInnerContentRect();
    }
}

void RenderLineBreak::deleteInlineBoxWrapper()
{
    if (!m_inlineBoxWrapper)
        return;
    if (!documentBeingDestroyed())
        m_inlineBoxWrapper->removeFromParent();
    delete m_inlineBoxWrapper;
    m_inlineBoxWrapper = nullptr;
}

void RenderNamedFlowFragment::attachRegion()
{
    RenderRegion::attachRegion();

    if (documentBeingDestroyed() || !isValid())
        return;

    updateRegionFlags();
}

RenderObject* RenderSVGContainer::removeChildNode(RenderObject* oldChild, bool fullRemove)
{
    ASSERT(oldChild->parent() == this);

    // So that we'll get the appropriate dirty bit set (either that a normal flow child got yanked or
    // that a positioned child got yanked).  We also repaint, so that the area exposed when the child
    // disappears gets repainted properly.
    if (!documentBeingDestroyed() && fullRemove) {
        oldChild->setNeedsLayoutAndPrefWidthsRecalc();
        oldChild->repaint();
    }

    // If we have a line box wrapper, delete it.
    oldChild->deleteLineBoxWrapper();

    if (!documentBeingDestroyed() && fullRemove) {
        // If oldChild is the start or end of the selection, then clear the selection to
        // avoid problems of invalid pointers.
        // FIXME: The SelectionController should be responsible for this when it
        // is notified of DOM mutations.
        if (oldChild->isSelectionBorder())
            view()->clearSelection();
    }

    // remove the child
    if (oldChild->previousSibling())
        oldChild->previousSibling()->setNextSibling(oldChild->nextSibling());
    if (oldChild->nextSibling())
        oldChild->nextSibling()->setPreviousSibling(oldChild->previousSibling());

    if (m_firstChild == oldChild)
        m_firstChild = oldChild->nextSibling();
    if (m_lastChild == oldChild)
        m_lastChild = oldChild->previousSibling();

    oldChild->setPreviousSibling(0);
    oldChild->setNextSibling(0);
    oldChild->setParent(0);

    if (AXObjectCache::accessibilityEnabled())
        document()->axObjectCache()->childrenChanged(this);

    return oldChild;
}

RenderObject* RenderRubyRun::removeChild(RenderObject& child)
{
    // If the child is a ruby text, then merge the ruby base with the base of
    // the right sibling run, if possible.
    if (!beingDestroyed() && !documentBeingDestroyed() && child.isRubyText()) {
        RenderRubyBase* base = rubyBase();
        RenderObject* rightNeighbour = nextSibling();
        if (base && rightNeighbour && rightNeighbour->isRubyRun()) {
            // Ruby run without a base can happen only at the first run.
            RenderRubyRun* rightRun = toRenderRubyRun(rightNeighbour);
            if (rightRun->hasRubyBase()) {
                RenderRubyBase* rightBase = rightRun->rubyBaseSafe();
                // Collect all children in a single base, then swap the bases.
                rightBase->mergeChildrenWithBase(base);
                moveChildTo(rightRun, base);
                rightRun->moveChildTo(this, rightBase);
                // The now empty ruby base will be removed below.
                ASSERT(!rubyBase()->firstChild());
            }
        }
    }

    RenderObject* next = RenderBlockFlow::removeChild(child);

    if (!beingDestroyed() && !documentBeingDestroyed()) {
        // Check if our base (if any) is now empty. If so, destroy it.
        RenderBlock* base = rubyBase();
        if (base && !base->firstChild()) {
            next = RenderBlockFlow::removeChild(*base);
            base->deleteLines();
            base->destroy();
        }

        // If any of the above leaves the run empty, destroy it as well.
        if (isEmpty()) {
            parent()->removeChild(*this);
            deleteLines();
            destroy();
            next = nullptr;
        }
    }
    
    return next;
}

void LayoutMultiColumnSet::attachToFlowThread()
{
    if (documentBeingDestroyed())
        return;

    if (!m_flowThread)
        return;

    m_flowThread->addColumnSetToThread(this);
}

void RenderSVGText::subtreeChildWasAdded(RenderObject* child)
{
    ASSERT(child);
    if (!shouldHandleSubtreeMutations() || documentBeingDestroyed())
        return;

    // Always protect the cache before clearing text positioning elements when the cache will subsequently be rebuilt.
    FontCachePurgePreventer fontCachePurgePreventer;

    // The positioning elements cache doesn't include the new 'child' yet. Clear the
    // cache, as the next buildLayoutAttributesForTextRenderer() call rebuilds it.
    m_layoutAttributesBuilder.clearTextPositioningElements();

    if (!child->isSVGInlineText() && !child->isSVGInline())
        return;

    // Detect changes in layout attributes and only measure those text parts that have changed!
    Vector<SVGTextLayoutAttributes*> newLayoutAttributes;
    collectLayoutAttributes(this, newLayoutAttributes);
    if (newLayoutAttributes.isEmpty()) {
        ASSERT(m_layoutAttributes.isEmpty());
        return;
    }

    // Compare m_layoutAttributes with newLayoutAttributes to figure out which attribute got added.
    size_t size = newLayoutAttributes.size();
    SVGTextLayoutAttributes* attributes = 0;
    for (size_t i = 0; i < size; ++i) {
        attributes = newLayoutAttributes[i];
        if (m_layoutAttributes.find(attributes) == notFound) {
            // Every time this is invoked, there's only a single new entry in the newLayoutAttributes list, compared to the old in m_layoutAttributes.
            bool stopAfterNext = false;
            SVGTextLayoutAttributes* previous = 0;
            SVGTextLayoutAttributes* next = 0;
            ASSERT_UNUSED(child, &attributes->context() == child);
            findPreviousAndNextAttributes(this, &attributes->context(), stopAfterNext, previous, next);

            if (previous)
                m_layoutAttributesBuilder.buildLayoutAttributesForTextRenderer(previous->context());
            m_layoutAttributesBuilder.buildLayoutAttributesForTextRenderer(attributes->context());
            if (next)
                m_layoutAttributesBuilder.buildLayoutAttributesForTextRenderer(next->context());
            break;
        }
    }

#ifndef NDEBUG
    // Verify that m_layoutAttributes only differs by a maximum of one entry.
    for (size_t i = 0; i < size; ++i)
        ASSERT(m_layoutAttributes.find(newLayoutAttributes[i]) != notFound || newLayoutAttributes[i] == attributes);
#endif

    m_layoutAttributes = newLayoutAttributes;
}

void RenderRubyRun::removeChild(RenderObject* child)
{
    // If the child is a ruby text, then merge the ruby base with the base of
    // the right sibling run, if possible.
    if (!m_beingDestroyed && !documentBeingDestroyed() && child->isRubyText()) {
        RenderRubyBase* base = rubyBase();
        RenderObject* rightNeighbour = nextSibling();
        if (base && rightNeighbour && rightNeighbour->isRubyRun()) {
            // Ruby run without a base can happen only at the first run.
            RenderRubyRun* rightRun = static_cast<RenderRubyRun*>(rightNeighbour);
            if (rightRun->hasRubyBase()) {
                RenderRubyBase* rightBase = rightRun->rubyBaseSafe();
                // Collect all children in a single base, then swap the bases.
                rightBase->moveChildren(base);
                moveChildTo(rightRun, base);
                rightRun->moveChildTo(this, rightBase);
                // The now empty ruby base will be removed below.
            }
        }
    }

    RenderBlock::removeChild(child);

    if (!m_beingDestroyed && !documentBeingDestroyed()) {
        // Check if our base (if any) is now empty. If so, destroy it.
        RenderBlock* base = rubyBase();
        if (base && !base->firstChild()) {
            RenderBlock::removeChild(base);
            base->deleteLineBoxTree();
            base->destroy();
        }

        // If any of the above leaves the run empty, destroy it as well.
        if (isEmpty()) {
            parent()->removeChild(this);
            deleteLineBoxTree();
            destroy();
        }
    }
}

void LayoutRubyRun::removeChild(LayoutObject* child)
{
    // If the child is a ruby text, then merge the ruby base with the base of
    // the right sibling run, if possible.
    if (!beingDestroyed() && !documentBeingDestroyed() && child->isRubyText()) {
        LayoutRubyBase* base = rubyBase();
        LayoutObject* rightNeighbour = nextSibling();
        if (base && rightNeighbour && rightNeighbour->isRubyRun()) {
            // Ruby run without a base can happen only at the first run.
            LayoutRubyRun* rightRun = toLayoutRubyRun(rightNeighbour);
            if (rightRun->hasRubyBase()) {
                LayoutRubyBase* rightBase = rightRun->rubyBaseSafe();
                // Collect all children in a single base, then swap the bases.
                rightBase->moveChildren(base);
                moveChildTo(rightRun, base);
                rightRun->moveChildTo(this, rightBase);
                // The now empty ruby base will be removed below.
                ASSERT(!rubyBase()->firstChild());
            }
        }
    }

    LayoutBlockFlow::removeChild(child);

    if (!beingDestroyed() && !documentBeingDestroyed()) {
        // Check if our base (if any) is now empty. If so, destroy it.
        LayoutBlock* base = rubyBase();
        if (base && !base->firstChild()) {
            LayoutBlockFlow::removeChild(base);
            base->deleteLineBoxTree();
            base->destroy();
        }

        // If any of the above leaves the run empty, destroy it as well.
        if (!hasRubyText() && !hasRubyBase()) {
            deleteLineBoxTree();
            destroy();
        }
    }
}

void RenderSVGText::subtreeChildWasRemoved(const Vector<SVGTextLayoutAttributes*, 2>& affectedAttributes)
{
    if (!shouldHandleSubtreeMutations() || documentBeingDestroyed()) {
        ASSERT(affectedAttributes.isEmpty());
        return;
    }

    // This is called immediately after subtreeChildWillBeDestroyed, once the RenderSVGInlineText::willBeDestroyed() method
    // passes on to the base class, which removes us from the render tree. At this point we can update the layout attributes.
    unsigned size = affectedAttributes.size();
    for (unsigned i = 0; i < size; ++i)
        m_layoutAttributesBuilder.buildLayoutAttributesForTextRenderer(affectedAttributes[i]->context());
}