C++ ShadowRoot::RemoveSheet方法代码示例

void
nsStyleLinkElement::UpdateStyleSheetScopedness(bool aIsNowScoped)
{
  if (!mStyleSheet) {
    return;
  }

  if (mStyleSheet->IsServo()) {
    // XXXheycam ServoStyleSheets don't support <style scoped>.
    NS_ERROR("stylo: ServoStyleSheets don't support <style scoped>");
    return;
  }

  CSSStyleSheet* sheet = mStyleSheet->AsGecko();

  nsCOMPtr<nsIContent> thisContent;
  CallQueryInterface(this, getter_AddRefs(thisContent));

  Element* oldScopeElement = sheet->GetScopeElement();
  Element* newScopeElement = aIsNowScoped ?
                               thisContent->GetParentElement() :
                               nullptr;

  if (oldScopeElement == newScopeElement) {
    return;
  }

  nsIDocument* document = thisContent->GetOwnerDocument();

  if (thisContent->IsInShadowTree()) {
    ShadowRoot* containingShadow = thisContent->GetContainingShadow();
    containingShadow->RemoveSheet(mStyleSheet);

    sheet->SetScopeElement(newScopeElement);

    containingShadow->InsertSheet(mStyleSheet, thisContent);
  } else {
    document->BeginUpdate(UPDATE_STYLE);
    document->RemoveStyleSheet(mStyleSheet);

    sheet->SetScopeElement(newScopeElement);

    document->AddStyleSheet(mStyleSheet);
    document->EndUpdate(UPDATE_STYLE);
  }

  if (oldScopeElement) {
    UpdateIsElementInStyleScopeFlagOnSubtree(oldScopeElement);
  }
  if (newScopeElement) {
    newScopeElement->SetIsElementInStyleScopeFlagOnSubtree(true);
  }
}

void
nsStyleLinkElement::UpdateStyleSheetScopedness(bool aIsNowScoped)
{
  if (!mStyleSheet) {
    return;
  }

  nsCOMPtr<nsIContent> thisContent;
  CallQueryInterface(this, getter_AddRefs(thisContent));

  Element* oldScopeElement = mStyleSheet->GetScopeElement();
  Element* newScopeElement = aIsNowScoped ?
                               thisContent->GetParentElement() :
                               nullptr;

  if (oldScopeElement == newScopeElement) {
    return;
  }

  nsIDocument* document = thisContent->GetOwnerDocument();

  if (thisContent->HasFlag(NODE_IS_IN_SHADOW_TREE)) {
    ShadowRoot* containingShadow = thisContent->GetContainingShadow();
    containingShadow->RemoveSheet(mStyleSheet);

    mStyleSheet->SetScopeElement(newScopeElement);

    containingShadow->InsertSheet(mStyleSheet, thisContent);
  } else {
    document->BeginUpdate(UPDATE_STYLE);
    document->RemoveStyleSheet(mStyleSheet);

    mStyleSheet->SetScopeElement(newScopeElement);

    document->AddStyleSheet(mStyleSheet);
    document->EndUpdate(UPDATE_STYLE);
  }

  if (oldScopeElement) {
    UpdateIsElementInStyleScopeFlagOnSubtree(oldScopeElement);
  }
  if (newScopeElement) {
    SetIsElementInStyleScopeFlagOnSubtree(newScopeElement);
  }
}

nsresult
nsStyleLinkElement::DoUpdateStyleSheet(nsIDocument* aOldDocument,
                                       ShadowRoot* aOldShadowRoot,
                                       nsICSSLoaderObserver* aObserver,
                                       bool* aWillNotify,
                                       bool* aIsAlternate,
                                       bool aForceUpdate)
{
  *aWillNotify = false;

  nsCOMPtr<nsIContent> thisContent;
  CallQueryInterface(this, getter_AddRefs(thisContent));

  // All instances of nsStyleLinkElement should implement nsIContent.
  NS_ENSURE_TRUE(thisContent, NS_ERROR_FAILURE);

  if (thisContent->IsInAnonymousSubtree() &&
      thisContent->IsAnonymousContentInSVGUseSubtree()) {
    // Stylesheets in <use>-cloned subtrees are disabled until we figure out
    // how they should behave.
    return NS_OK;
  }

  // Check for a ShadowRoot because link elements are inert in a
  // ShadowRoot.
  ShadowRoot* containingShadow = thisContent->GetContainingShadow();
  if (thisContent->IsHTMLElement(nsGkAtoms::link) &&
      (aOldShadowRoot || containingShadow)) {
    return NS_OK;
  }

  Element* oldScopeElement = GetScopeElement(mStyleSheet);

  if (mStyleSheet && (aOldDocument || aOldShadowRoot)) {
    MOZ_ASSERT(!(aOldDocument && aOldShadowRoot),
               "ShadowRoot content is never in document, thus "
               "there should not be a old document and old "
               "ShadowRoot simultaneously.");

    // We're removing the link element from the document or shadow tree,
    // unload the stylesheet.  We want to do this even if updates are
    // disabled, since otherwise a sheet with a stale linking element pointer
    // will be hanging around -- not good!
    if (aOldShadowRoot) {
      aOldShadowRoot->RemoveSheet(mStyleSheet);
    } else {
      aOldDocument->BeginUpdate(UPDATE_STYLE);
      aOldDocument->RemoveStyleSheet(mStyleSheet);
      aOldDocument->EndUpdate(UPDATE_STYLE);
    }

    nsStyleLinkElement::SetStyleSheet(nullptr);
    if (oldScopeElement) {
      UpdateIsElementInStyleScopeFlagOnSubtree(oldScopeElement);
    }
  }

  // When static documents are created, stylesheets are cloned manually.
  if (mDontLoadStyle || !mUpdatesEnabled ||
      thisContent->OwnerDoc()->IsStaticDocument()) {
    return NS_OK;
  }

  nsCOMPtr<nsIDocument> doc = thisContent->IsInShadowTree() ?
    thisContent->OwnerDoc() : thisContent->GetUncomposedDoc();
  if (!doc || !doc->CSSLoader()->GetEnabled()) {
    return NS_OK;
  }

  bool isInline;
  nsCOMPtr<nsIURI> uri = GetStyleSheetURL(&isInline);

  if (!aForceUpdate && mStyleSheet && !isInline && uri) {
    nsIURI* oldURI = mStyleSheet->GetSheetURI();
    if (oldURI) {
      bool equal;
      nsresult rv = oldURI->Equals(uri, &equal);
      if (NS_SUCCEEDED(rv) && equal) {
        return NS_OK; // We already loaded this stylesheet
      }
    }
  }

  if (mStyleSheet) {
    if (thisContent->IsInShadowTree()) {
      ShadowRoot* containingShadow = thisContent->GetContainingShadow();
      containingShadow->RemoveSheet(mStyleSheet);
    } else {
      doc->BeginUpdate(UPDATE_STYLE);
      doc->RemoveStyleSheet(mStyleSheet);
      doc->EndUpdate(UPDATE_STYLE);
    }

    nsStyleLinkElement::SetStyleSheet(nullptr);
  }

  if (!uri && !isInline) {
    return NS_OK; // If href is empty and this is not inline style then just bail
  }

//.........这里部分代码省略.........