C++ ContainerNode::renderer方法代码示例

bool HTMLEmbedElement::rendererIsNeeded(const NodeRenderingContext& context)
{
    if (isImageType())
        return HTMLPlugInImageElement::rendererIsNeeded(context);

    Frame* frame = document()->frame();
    if (!frame)
        return false;

    // If my parent is an <object> and is not set to use fallback content, I
    // should be ignored and not get a renderer.
    ContainerNode* p = parentNode();
    if (p && p->hasTagName(objectTag)) {
        ASSERT(p->renderer());
        if (!static_cast<HTMLObjectElement*>(p)->useFallbackContent()) {
            ASSERT(!p->renderer()->isEmbeddedObject());
            return false;
        }
    }

#if ENABLE(DASHBOARD_SUPPORT)
    // Workaround for <rdar://problem/6642221>. 
    if (Settings* settings = frame->settings()) {
        if (settings->usesDashboardBackwardCompatibilityMode())
            return true;
    }
#endif

    return HTMLPlugInImageElement::rendererIsNeeded(context);
}

void Text::reattachIfNeeded(const AttachContext& context)
{
    bool rendererIsNeeded = false;
    ContainerNode* renderingParent = NodeRenderingTraversal::parent(*this);
    if (renderingParent) {
        if (RenderObject* parentRenderer = renderingParent->renderer()) {
            if (textRendererIsNeeded(*parentRenderer->style(), *parentRenderer))
                rendererIsNeeded = true;
        }
    }

    if (rendererIsNeeded == !!renderer())
        return;

    // The following is almost the same as Node::reattach() except that we create renderer only if needed.
    // Not calling reattach() to avoid repeated calls to Text::textRendererIsNeeded().
    AttachContext reattachContext(context);
    reattachContext.performingReattach = true;

    if (styleChangeType() < NeedsReattachStyleChange)
        detach(reattachContext);
    if (rendererIsNeeded)
        RenderTreeBuilderForText(*this, renderingParent->renderer()).createRenderer();
    CharacterData::attach(reattachContext);
}

bool HTMLEmbedElement::rendererIsNeeded(const RenderStyle& style)
{
    if (isImageType())
        return HTMLPlugInImageElement::rendererIsNeeded(style);

    // If my parent is an <object> and is not set to use fallback content, I
    // should be ignored and not get a renderer.
    ContainerNode* p = parentNode();
    if (p && p->hasTagName(objectTag)) {
        if (!p->renderer())
            return false;
        if (!toHTMLObjectElement(p)->useFallbackContent()) {
            ASSERT(!p->renderer()->isEmbeddedObject());
            return false;
        }
    }

#if ENABLE(DASHBOARD_SUPPORT)
    // Workaround for <rdar://problem/6642221>.
    if (document().frame()->settings().usesDashboardBackwardCompatibilityMode())
        return true;
#endif

    return HTMLPlugInImageElement::rendererIsNeeded(style);
}

void SimplifyMarkupCommand::doApply()
{
    ContainerNode* rootNode = m_firstNode->parentNode();
    WillBeHeapVector<RefPtrWillBeMember<ContainerNode>> nodesToRemove;

    // Walk through the inserted nodes, to see if there are elements that could be removed
    // without affecting the style. The goal is to produce leaner markup even when starting
    // from a verbose fragment.
    // We look at inline elements as well as non top level divs that don't have attributes.
    for (Node* node = m_firstNode.get(); node && node != m_nodeAfterLast; node = NodeTraversal::next(*node)) {
        if (node->hasChildren() || (node->isTextNode() && node->nextSibling()))
            continue;

        ContainerNode* startingNode = node->parentNode();
        if (!startingNode)
            continue;
        RenderStyle* startingStyle = startingNode->renderStyle();
        if (!startingStyle)
            continue;
        ContainerNode* currentNode = startingNode;
        ContainerNode* topNodeWithStartingStyle = nullptr;
        while (currentNode != rootNode) {
            if (currentNode->parentNode() != rootNode && isRemovableBlock(currentNode))
                nodesToRemove.append(currentNode);

            currentNode = currentNode->parentNode();
            if (!currentNode)
                break;

            if (!currentNode->renderer() || !currentNode->renderer()->isRenderInline() || toRenderInline(currentNode->renderer())->alwaysCreateLineBoxes())
                continue;

            if (currentNode->firstChild() != currentNode->lastChild()) {
                topNodeWithStartingStyle = 0;
                break;
            }

            if (!currentNode->renderStyle()->visualInvalidationDiff(*startingStyle).hasDifference())
                topNodeWithStartingStyle = currentNode;

        }
        if (topNodeWithStartingStyle) {
            for (ContainerNode* node = startingNode; node != topNodeWithStartingStyle; node = node->parentNode())
                nodesToRemove.append(node);
        }
    }

    // we perform all the DOM mutations at once.
    for (size_t i = 0; i < nodesToRemove.size(); ++i) {
        // FIXME: We can do better by directly moving children from nodesToRemove[i].
        int numPrunedAncestors = pruneSubsequentAncestorsToRemove(nodesToRemove, i);
        if (numPrunedAncestors < 0)
            continue;
        removeNodePreservingChildren(nodesToRemove[i], AssumeContentIsAlwaysEditable);
        i += numPrunedAncestors;
    }
}

void RemoveNodeCommand::doApply()
{
    ContainerNode* parent = m_node->parentNode();
    if (!parent || (m_shouldAssumeContentIsAlwaysEditable == DoNotAssumeContentIsAlwaysEditable
        && !parent->isContentEditable(Node::UserSelectAllIsAlwaysNonEditable) && parent->renderer()))
        return;
    ASSERT(parent->isContentEditable(Node::UserSelectAllIsAlwaysNonEditable) || !parent->renderer());

    m_parent = parent;
    m_refChild = m_node->nextSibling();

    m_node->remove(IGNORE_EXCEPTION);
}

void SVGFELightElement::svgAttributeChanged(const QualifiedName& attrName)
{
    SVGElement::svgAttributeChanged(attrName);

    if (attrName == SVGNames::azimuthAttr
        || attrName == SVGNames::elevationAttr
        || attrName == SVGNames::xAttr
        || attrName == SVGNames::yAttr
        || attrName == SVGNames::zAttr
        || attrName == SVGNames::pointsAtXAttr
        || attrName == SVGNames::pointsAtYAttr
        || attrName == SVGNames::pointsAtZAttr
        || attrName == SVGNames::specularExponentAttr
        || attrName == SVGNames::limitingConeAngleAttr) {
        ContainerNode* parent = parentNode();
        if (!parent)
            return;

        RenderObject* renderer = parent->renderer();
        if (!renderer || !renderer->isSVGResourceFilterPrimitive())
            return;

        if (parent->hasTagName(SVGNames::feDiffuseLightingTag)) {
            SVGFEDiffuseLightingElement* diffuseLighting = static_cast<SVGFEDiffuseLightingElement*>(parent);
            diffuseLighting->lightElementAttributeChanged(this, attrName);
            return;
        }
        // Handler for SpecularLighting has not implemented yet.
        RenderSVGResource::markForLayoutAndParentResourceInvalidation(renderer);
    }
}

static void createRendererIfNeeded(Element& element, RenderStyle* resolvedStyle)
{
    ASSERT(!element.renderer());

    Document& document = element.document();
    ContainerNode* renderingParentNode = NodeRenderingTraversal::parent(&element);

    RefPtr<RenderStyle> style = resolvedStyle;

    element.setIsInsideRegion(false);

    if (!shouldCreateRenderer(element, renderingParentNode) && !elementInsideRegionNeedsRenderer(element, renderingParentNode, style))
        return;

    if (!style)
        style = element.styleForRenderer();

    RenderNamedFlowThread* parentFlowRenderer = 0;
#if ENABLE(CSS_REGIONS)
    parentFlowRenderer = moveToFlowThreadIfNeeded(element, *style);
#endif

    if (!element.rendererIsNeeded(*style))
        return;

    RenderObject* parentRenderer;
    RenderObject* nextRenderer;
    if (parentFlowRenderer) {
        parentRenderer = parentFlowRenderer;
        nextRenderer = parentFlowRenderer->nextRendererForNode(&element);
    } else {
        parentRenderer = renderingParentNode->renderer();
        nextRenderer = nextSiblingRenderer(element, renderingParentNode);
    }

    RenderObject* newRenderer = element.createRenderer(document.renderArena(), style.get());
    if (!newRenderer)
        return;
    if (!parentRenderer->isChildAllowed(newRenderer, style.get())) {
        newRenderer->destroy();
        return;
    }

    // Make sure the RenderObject already knows it is going to be added to a RenderFlowThread before we set the style
    // for the first time. Otherwise code using inRenderFlowThread() in the styleWillChange and styleDidChange will fail.
    newRenderer->setFlowThreadState(parentRenderer->flowThreadState());

    element.setRenderer(newRenderer);
    newRenderer->setAnimatableStyle(style.release()); // setAnimatableStyle() can depend on renderer() already being set.

#if ENABLE(FULLSCREEN_API)
    if (document.webkitIsFullScreen() && document.webkitCurrentFullScreenElement() == &element) {
        newRenderer = RenderFullScreen::wrapRenderer(newRenderer, parentRenderer, &document);
        if (!newRenderer)
            return;
    }
#endif
    // Note: Adding newRenderer instead of renderer(). renderer() may be a child of newRenderer.
    parentRenderer->addChild(newRenderer, nextRenderer);
}

void RenderTreeUpdater::updateRenderTree(ContainerNode& root)
{
    ASSERT(root.renderer());
    ASSERT(m_parentStack.isEmpty());

    m_parentStack.append(Parent(root));

    auto descendants = composedTreeDescendants(root);
    auto it = descendants.begin();
    auto end = descendants.end();

    // FIXME: https://bugs.webkit.org/show_bug.cgi?id=156172
    it.dropAssertions();

    while (it != end) {
        popParentsToDepth(it.depth());

        auto& node = *it;

        if (auto* renderer = node.renderer())
            renderTreePosition().invalidateNextSibling(*renderer);

        if (is<Text>(node)) {
            auto& text = downcast<Text>(node);
            if (parent().styleChange == Style::Detach || m_styleUpdate->textUpdate(text) || m_invalidatedWhitespaceOnlyTextSiblings.contains(&text))
                updateTextRenderer(text);

            it.traverseNextSkippingChildren();
            continue;
        }

        auto& element = downcast<Element>(node);

        auto* elementUpdate = m_styleUpdate->elementUpdate(element);
        if (!elementUpdate) {
            it.traverseNextSkippingChildren();
            continue;
        }

        updateElementRenderer(element, *elementUpdate);

        bool mayHaveRenderedDescendants = element.renderer() || (element.hasDisplayContents() && shouldCreateRenderer(element, renderTreePosition().parent()));
        if (!mayHaveRenderedDescendants) {
            it.traverseNextSkippingChildren();
            continue;
        }

        pushParent(element, elementUpdate ? elementUpdate->change : Style::NoChange);

        it.traverseNext();
    }

    popParentsToDepth(0);

    m_invalidatedWhitespaceOnlyTextSiblings.clear();
}

bool HTMLEmbedElement::rendererIsNeeded(const RenderStyle& style)
{
    if (isImageType())
        return HTMLPlugInImageElement::rendererIsNeeded(style);

    Frame* frame = document().frame();
    if (!frame)
        return false;

    // If my parent is an <object> and is not set to use fallback content, I
    // should be ignored and not get a renderer.
    ContainerNode* p = parentNode();
    if (p && p->hasTagName(objectTag)) {
        ASSERT(p->renderer());
        if (!toHTMLObjectElement(p)->useFallbackContent()) {
            ASSERT(!p->renderer()->isEmbeddedObject());
            return false;
        }
    }
    return HTMLPlugInImageElement::rendererIsNeeded(style);
}

void SVGFELightElement::childrenChanged(const ChildChange& change)
{
    SVGElement::childrenChanged(change);

    if (change.source == ChildChangeSourceParser)
        return;
    ContainerNode* parent = parentNode();
    if (!parent)
        return;
    RenderElement* renderer = parent->renderer();
    if (renderer && renderer->isSVGResourceFilterPrimitive())
        RenderSVGResource::markForLayoutAndParentResourceInvalidation(*renderer);
}

void invalidateFilterPrimitiveParent(SVGElement* element)
{
    if (!element)
        return;

    ContainerNode* parent = element->parentNode();

    if (!parent)
        return;

    RenderElement* renderer = parent->renderer();
    if (!renderer || !renderer->isSVGResourceFilterPrimitive())
        return;

    RenderSVGResource::markForLayoutAndParentResourceInvalidation(*renderer, false);
}

static void createTextRendererIfNeeded(Text& textNode)
{
    ASSERT(!textNode.renderer());

    ContainerNode* renderingParentNode = NodeRenderingTraversal::parent(&textNode);
    if (!renderingParentNode)
        return;
    RenderObject* parentRenderer = renderingParentNode->renderer();
    if (!parentRenderer || !parentRenderer->canHaveChildren())
        return;
    if (!renderingParentNode->childShouldCreateRenderer(&textNode))
        return;

    Document& document = textNode.document();
    RefPtr<RenderStyle> style;
    bool resetStyleInheritance = textNode.parentNode()->isShadowRoot() && toShadowRoot(textNode.parentNode())->resetStyleInheritance();
    if (resetStyleInheritance)
        style = document.ensureStyleResolver().defaultStyleForElement();
    else
        style = parentRenderer->style();

    if (!textRendererIsNeeded(textNode, *parentRenderer, *style))
        return;
    RenderText* newRenderer = textNode.createTextRenderer(document.renderArena(), style.get());
    if (!newRenderer)
        return;
    if (!parentRenderer->isChildAllowed(newRenderer, style.get())) {
        newRenderer->destroy();
        return;
    }

    // Make sure the RenderObject already knows it is going to be added to a RenderFlowThread before we set the style
    // for the first time. Otherwise code using inRenderFlowThread() in the styleWillChange and styleDidChange will fail.
    newRenderer->setFlowThreadState(parentRenderer->flowThreadState());

    RenderObject* nextRenderer = nextSiblingRenderer(textNode);
    textNode.setRenderer(newRenderer);
    // Parent takes care of the animations, no need to call setAnimatableStyle.
    newRenderer->setStyle(style.release());
    parentRenderer->addChild(newRenderer, nextRenderer);

    Node* sibling = textNode.nextSibling();
    if (sibling && !sibling->renderer() && sibling->attached())
        createTextRenderersForSiblingsAfterAttachIfNeeded(sibling);
}

void SVGFELightElement::svgAttributeChanged(const QualifiedName& attrName)
{
    if (!isSupportedAttribute(attrName)) {
        SVGElement::svgAttributeChanged(attrName);
        return;
    }

    SVGElementInstance::InvalidationGuard invalidationGuard(this);
    
    if (attrName == SVGNames::azimuthAttr
        || attrName == SVGNames::elevationAttr
        || attrName == SVGNames::xAttr
        || attrName == SVGNames::yAttr
        || attrName == SVGNames::zAttr
        || attrName == SVGNames::pointsAtXAttr
        || attrName == SVGNames::pointsAtYAttr
        || attrName == SVGNames::pointsAtZAttr
        || attrName == SVGNames::specularExponentAttr
        || attrName == SVGNames::limitingConeAngleAttr) {
        ContainerNode* parent = parentNode();
        if (!parent)
            return;

        RenderObject* renderer = parent->renderer();
        if (!renderer || !renderer->isSVGResourceFilterPrimitive())
            return;

        if (parent->hasTagName(SVGNames::feDiffuseLightingTag)) {
            SVGFEDiffuseLightingElement* diffuseLighting = static_cast<SVGFEDiffuseLightingElement*>(parent);
            diffuseLighting->lightElementAttributeChanged(this, attrName);
            return;
        } else if (parent->hasTagName(SVGNames::feSpecularLightingTag)) {
            SVGFESpecularLightingElement* specularLighting = static_cast<SVGFESpecularLightingElement*>(parent);
            specularLighting->lightElementAttributeChanged(this, attrName);
            return;
        }
    }

    ASSERT_NOT_REACHED();
}

static bool isDeletableElement(const Node* node)
{
    if (!node || !node->isHTMLElement() || !node->inDocument() || !node->rendererIsEditable())
        return false;

    // In general we want to only draw the UI around object of a certain area, but we still keep the min width/height to
    // make sure we don't end up with very thin or very short elements getting the UI.
    const int minimumArea = 2500;
    const int minimumWidth = 48;
    const int minimumHeight = 16;
    const unsigned minimumVisibleBorders = 1;

    RenderObject* renderer = node->renderer();
    if (!renderer || !renderer->isBox())
        return false;

    // Disallow the body element since it isn't practical to delete, and the deletion UI would be clipped.
    if (node->hasTagName(bodyTag))
        return false;

    // Disallow elements with any overflow clip, since the deletion UI would be clipped as well. <rdar://problem/6840161>
    if (renderer->hasOverflowClip())
        return false;

    // Disallow Mail blockquotes since the deletion UI would get in the way of editing for these.
    if (isMailBlockquote(node))
        return false;

    RenderBox* box = toRenderBox(renderer);
    IntRect borderBoundingBox = box->borderBoundingBox();
    if (borderBoundingBox.width() < minimumWidth || borderBoundingBox.height() < minimumHeight)
        return false;

    if ((borderBoundingBox.width() * borderBoundingBox.height()) < minimumArea)
        return false;

    if (renderer->isTable())
        return true;

    if (node->hasTagName(ulTag) || node->hasTagName(olTag) || node->hasTagName(iframeTag))
        return true;

    if (renderer->isOutOfFlowPositioned())
        return true;

    if (renderer->isRenderBlock() && !renderer->isTableCell()) {
        RenderStyle* style = renderer->style();
        if (!style)
            return false;

        // Allow blocks that have background images
        if (style->hasBackgroundImage()) {
            for (const FillLayer* background = style->backgroundLayers(); background; background = background->next()) {
                if (background->image() && background->image()->canRender(renderer, 1))
                    return true;
            }
        }

        // Allow blocks with a minimum number of non-transparent borders
        unsigned visibleBorders = style->borderTop().isVisible() + style->borderBottom().isVisible() + style->borderLeft().isVisible() + style->borderRight().isVisible();
        if (visibleBorders >= minimumVisibleBorders)
            return true;

        // Allow blocks that have a different background from it's parent
        ContainerNode* parentNode = node->parentNode();
        if (!parentNode)
            return false;

        RenderObject* parentRenderer = parentNode->renderer();
        if (!parentRenderer)
            return false;

        RenderStyle* parentStyle = parentRenderer->style();
        if (!parentStyle)
            return false;

        if (renderer->hasBackground() && (!parentRenderer->hasBackground() || style->visitedDependentColor(CSSPropertyBackgroundColor) != parentStyle->visitedDependentColor(CSSPropertyBackgroundColor)))
            return true;
    }

    return false;
}

Node* StyledMarkupAccumulator::traverseNodesForSerialization(Node* startNode, Node* pastEnd, NodeTraversalMode traversalMode)
{
    const bool shouldEmit = traversalMode == EmitString;
    Vector<Node*> ancestorsToClose;
    Node* next;
    Node* lastClosed = 0;
    for (Node* n = startNode; n != pastEnd; n = next) {
        // According to <rdar://problem/5730668>, it is possible for n to blow
        // past pastEnd and become null here. This shouldn't be possible.
        // This null check will prevent crashes (but create too much markup)
        // and the ASSERT will hopefully lead us to understanding the problem.
        ASSERT(n);
        if (!n)
            break;
        
        next = NodeTraversal::next(n);
        bool openedTag = false;

        if (isBlock(n) && canHaveChildrenForEditing(n) && next == pastEnd)
            // Don't write out empty block containers that aren't fully selected.
            continue;

        if (!n->renderer() && !enclosingNodeWithTag(firstPositionInOrBeforeNode(n), selectTag)) {
            next = NodeTraversal::nextSkippingChildren(n);
            // Don't skip over pastEnd.
            if (pastEnd && pastEnd->isDescendantOf(n))
                next = pastEnd;
        } else {
            // Add the node to the markup if we're not skipping the descendants
            if (shouldEmit)
                appendStartTag(n);

            // If node has no children, close the tag now.
            if (!n->childNodeCount()) {
                if (shouldEmit)
                    appendEndTag(n);
                lastClosed = n;
            } else {
                openedTag = true;
                ancestorsToClose.append(n);
            }
        }

        // If we didn't insert open tag and there's no more siblings or we're at the end of the traversal, take care of ancestors.
        // FIXME: What happens if we just inserted open tag and reached the end?
        if (!openedTag && (!n->nextSibling() || next == pastEnd)) {
            // Close up the ancestors.
            while (!ancestorsToClose.isEmpty()) {
                Node* ancestor = ancestorsToClose.last();
                if (next != pastEnd && next->isDescendantOf(ancestor))
                    break;
                // Not at the end of the range, close ancestors up to sibling of next node.
                if (shouldEmit)
                    appendEndTag(ancestor);
                lastClosed = ancestor;
                ancestorsToClose.removeLast();
            }

            // Surround the currently accumulated markup with markup for ancestors we never opened as we leave the subtree(s) rooted at those ancestors.
            ContainerNode* nextParent = next ? next->parentNode() : 0;
            if (next != pastEnd && n != nextParent) {
                Node* lastAncestorClosedOrSelf = n->isDescendantOf(lastClosed) ? lastClosed : n;
                for (ContainerNode* parent = lastAncestorClosedOrSelf->parentNode(); parent && parent != nextParent; parent = parent->parentNode()) {
                    // All ancestors that aren't in the ancestorsToClose list should either be a) unrendered:
                    if (!parent->renderer())
                        continue;
                    // or b) ancestors that we never encountered during a pre-order traversal starting at startNode:
                    ASSERT(startNode->isDescendantOf(parent));
                    if (shouldEmit)
                        wrapWithNode(parent);
                    lastClosed = parent;
                }
            }
        }
    }

    return lastClosed;
}