C++ LayoutObject::destroy方法代码示例

void PseudoElement::attach(const AttachContext& context)
{
    ASSERT(!layoutObject());

    Element::attach(context);

    LayoutObject* renderer = this->layoutObject();
    if (!renderer)
        return;

    ComputedStyle& style = renderer->mutableStyleRef();
    if (style.styleType() != BEFORE && style.styleType() != AFTER)
        return;
    ASSERT(style.contentData());

    for (const ContentData* content = style.contentData(); content; content = content->next()) {
        LayoutObject* child = content->createLayoutObject(document(), style);
        if (renderer->isChildAllowed(child, style)) {
            renderer->addChild(child);
            if (child->isQuote())
                toLayoutQuote(child)->attachQuote();
        } else
            child->destroy();
    }
}

bool LayoutListItem::updateMarkerLocation()
{
    ASSERT(m_marker);

    LayoutObject* markerParent = m_marker->parent();
    LayoutObject* lineBoxParent = getParentOfFirstLineBox(this, m_marker);
    if (!lineBoxParent) {
        // If the marker is currently contained inside an anonymous box, then we
        // are the only item in that anonymous box (since no line box parent was
        // found). It's ok to just leave the marker where it is in this case.
        if (markerParent && markerParent->isAnonymousBlock())
            lineBoxParent = markerParent;
        else
            lineBoxParent = this;
    }

    if (markerParent != lineBoxParent) {
        m_marker->remove();
        lineBoxParent->addChild(m_marker, firstNonMarkerChild(lineBoxParent));
        m_marker->updateMarginsAndContent();
        // If markerParent is an anonymous block with no children, destroy it.
        if (markerParent && markerParent->isAnonymousBlock() && !toLayoutBlock(markerParent)->firstChild() && !toLayoutBlock(markerParent)->continuation())
            markerParent->destroy();
        return true;
    }

    return false;
}

void LayoutTreeBuilderForElement::createLayoutObject()
{
    ComputedStyle& style = this->style();

    LayoutObject* newLayoutObject = m_node->createLayoutObject(style);
    if (!newLayoutObject)
        return;

    LayoutObject* parentLayoutObject = this->parentLayoutObject();

    if (!parentLayoutObject->isChildAllowed(newLayoutObject, style)) {
        newLayoutObject->destroy();
        return;
    }

    // Make sure the LayoutObject already knows it is going to be added to a LayoutFlowThread before we set the style
    // for the first time. Otherwise code using inLayoutFlowThread() in the styleWillChange and styleDidChange will fail.
    newLayoutObject->setIsInsideFlowThread(parentLayoutObject->isInsideFlowThread());

    LayoutObject* nextLayoutObject = this->nextLayoutObject();
    m_node->setLayoutObject(newLayoutObject);
    newLayoutObject->setStyle(&style); // setStyle() can depend on layoutObject() already being set.

    if (Fullscreen::isActiveFullScreenElement(*m_node)) {
        newLayoutObject = LayoutFullScreen::wrapLayoutObject(newLayoutObject, parentLayoutObject, &m_node->document());
        if (!newLayoutObject)
            return;
    }

    // Note: Adding newLayoutObject instead of layoutObject(). layoutObject() may be a child of newLayoutObject.
    parentLayoutObject->addChild(newLayoutObject, nextLayoutObject);
}

void PseudoElement::attachLayoutTree(const AttachContext& context) {
  DCHECK(!layoutObject());

  Element::attachLayoutTree(context);

  LayoutObject* layoutObject = this->layoutObject();
  if (!layoutObject)
    return;

  ComputedStyle& style = layoutObject->mutableStyleRef();
  if (style.styleType() != PseudoIdBefore && style.styleType() != PseudoIdAfter)
    return;
  DCHECK(style.contentData());

  for (const ContentData* content = style.contentData(); content;
       content = content->next()) {
    LayoutObject* child = content->createLayoutObject(document(), style);
    if (layoutObject->isChildAllowed(child, style)) {
      layoutObject->addChild(child);
      if (child->isQuote())
        toLayoutQuote(child)->attachQuote();
    } else {
      child->destroy();
    }
  }
}

TEST_F(LayoutPartTest, DestroyUpdatesImageQualityController)
{
    RawPtr<Element> element = HTMLElement::create(HTMLNames::divTag, document());
    LayoutObject* part = new OverriddenLayoutPart(element.get());
    // The third and forth arguments are not important in this test.
    ImageQualityController::imageQualityController()->set(*part, 0, this, LayoutSize(1, 1), false);
    EXPECT_TRUE(ImageQualityController::has(*part));
    part->destroy();
    EXPECT_FALSE(ImageQualityController::has(*part));
}

void FirstLetterPseudoElement::attachFirstLetterTextLayoutObjects()
{
    LayoutObject* nextLayoutObject = FirstLetterPseudoElement::firstLetterTextLayoutObject(*this);
    ASSERT(nextLayoutObject);
    ASSERT(nextLayoutObject->isText());

    // The original string is going to be either a generated content string or a DOM node's
    // string. We want the original string before it got transformed in case first-letter has
    // no text-transform or a different text-transform applied to it.
    String oldText = toLayoutText(nextLayoutObject)->isTextFragment() ? toLayoutTextFragment(nextLayoutObject)->completeText() : toLayoutText(nextLayoutObject)->originalText();
    ASSERT(oldText.impl());

    ComputedStyle* pseudoStyle = styleForFirstLetter(nextLayoutObject->parent());
    layoutObject()->setStyle(pseudoStyle);

    // FIXME: This would already have been calculated in firstLetterLayoutObject. Can we pass the length through?
    unsigned length = FirstLetterPseudoElement::firstLetterLength(oldText);

    // Construct a text fragment for the text after the first letter.
    // This text fragment might be empty.
    LayoutTextFragment* remainingText =
        new LayoutTextFragment(nextLayoutObject->node() ? nextLayoutObject->node() : &nextLayoutObject->document(), oldText.impl(), length, oldText.length() - length);
    remainingText->setFirstLetterPseudoElement(this);
    remainingText->setIsRemainingTextLayoutObject(true);
    remainingText->setStyle(nextLayoutObject->mutableStyle());

    if (remainingText->node())
        remainingText->node()->setLayoutObject(remainingText);

    m_remainingTextLayoutObject = remainingText;

    LayoutObject* nextSibling = layoutObject()->nextSibling();
    layoutObject()->parent()->addChild(remainingText, nextSibling);

    // Construct text fragment for the first letter.
    LayoutTextFragment* letter = new LayoutTextFragment(&nextLayoutObject->document(), oldText.impl(), 0, length);
    letter->setFirstLetterPseudoElement(this);
    letter->setStyle(pseudoStyle);
    layoutObject()->addChild(letter);

    nextLayoutObject->destroy();
}