gecko/content/base/src/ShadowRoot.cpp

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "mozilla/Preferences.h"
#include "mozilla/dom/ShadowRoot.h"
#include "mozilla/dom/ShadowRootBinding.h"
#include "mozilla/dom/DocumentFragment.h"
#include "nsContentUtils.h"
#include "nsDOMClassInfoID.h"
#include "nsIDOMHTMLElement.h"
#include "mozilla/dom/Element.h"
#include "nsXBLPrototypeBinding.h"

using namespace mozilla;
using namespace mozilla::dom;

static PLDHashOperator
IdentifierMapEntryTraverse(nsIdentifierMapEntry *aEntry, void *aArg)
{
  nsCycleCollectionTraversalCallback *cb =
    static_cast<nsCycleCollectionTraversalCallback*>(aArg);
  aEntry->Traverse(cb);
  return PL_DHASH_NEXT;
}

NS_IMPL_CYCLE_COLLECTION_CLASS(ShadowRoot)

NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(ShadowRoot,
                                                  DocumentFragment)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mHost)
  tmp->mIdentifierMap.EnumerateEntries(IdentifierMapEntryTraverse, &cb);
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END

NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(ShadowRoot,
                                                DocumentFragment)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mHost)
  tmp->mIdentifierMap.Clear();
NS_IMPL_CYCLE_COLLECTION_UNLINK_END

DOMCI_DATA(ShadowRoot, ShadowRoot)

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(ShadowRoot)
  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIContent)
NS_INTERFACE_MAP_END_INHERITING(DocumentFragment)

NS_IMPL_ADDREF_INHERITED(ShadowRoot, DocumentFragment)
NS_IMPL_RELEASE_INHERITED(ShadowRoot, DocumentFragment)

ShadowRoot::ShadowRoot(nsIContent* aContent,
                       already_AddRefed<nsINodeInfo> aNodeInfo)
  : DocumentFragment(aNodeInfo), mHost(aContent)
{
  SetHost(aContent);
  SetFlags(NODE_IS_IN_SHADOW_TREE);
  // ShadowRoot isn't really in the document but it behaves like it is.
  SetInDocument();
  DOMSlots()->mBindingParent = aContent;
  DOMSlots()->mContainingShadow = this;
}

ShadowRoot::~ShadowRoot()
{
  ClearInDocument();
  SetHost(nullptr);
}

JSObject*
ShadowRoot::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aScope)
{
  return mozilla::dom::ShadowRootBinding::Wrap(aCx, aScope, this);
}

ShadowRoot*
ShadowRoot::FromNode(nsINode* aNode)
{
  if (aNode->HasFlag(NODE_IS_IN_SHADOW_TREE) && !aNode->GetParentNode()) {
    MOZ_ASSERT(aNode->NodeType() == nsIDOMNode::DOCUMENT_FRAGMENT_NODE,
               "ShadowRoot is a document fragment.");
    return static_cast<ShadowRoot*>(aNode);
  }

  return nullptr;
}

Element*
ShadowRoot::GetElementById(const nsAString& aElementId)
{
  nsIdentifierMapEntry *entry = mIdentifierMap.GetEntry(aElementId);
  return entry ? entry->GetIdElement() : nullptr;
}

already_AddRefed<nsContentList>
ShadowRoot::GetElementsByTagName(const nsAString& aTagName)
{
  return NS_GetContentList(this, kNameSpaceID_Unknown, aTagName);
}

already_AddRefed<nsContentList>
ShadowRoot::GetElementsByTagNameNS(const nsAString& aNamespaceURI,
                                   const nsAString& aLocalName)
{
  int32_t nameSpaceId = kNameSpaceID_Wildcard;

  if (!aNamespaceURI.EqualsLiteral("*")) {
    nsresult rv =
      nsContentUtils::NameSpaceManager()->RegisterNameSpace(aNamespaceURI,
                                                            nameSpaceId);
    NS_ENSURE_SUCCESS(rv, nullptr);
  }

  NS_ASSERTION(nameSpaceId != kNameSpaceID_Unknown, "Unexpected namespace ID!");

  return NS_GetContentList(this, nameSpaceId, aLocalName);
}

void
ShadowRoot::AddToIdTable(Element* aElement, nsIAtom* aId)
{
  nsIdentifierMapEntry *entry =
    mIdentifierMap.PutEntry(nsDependentAtomString(aId));
  if (entry) {
    entry->AddIdElement(aElement);
  }
}

void
ShadowRoot::RemoveFromIdTable(Element* aElement, nsIAtom* aId)
{
  nsIdentifierMapEntry *entry =
    mIdentifierMap.GetEntry(nsDependentAtomString(aId));
  if (entry) {
    entry->RemoveIdElement(aElement);
    if (entry->IsEmpty()) {
      mIdentifierMap.RawRemoveEntry(entry);
    }
  }
}

already_AddRefed<nsContentList>
ShadowRoot::GetElementsByClassName(const nsAString& aClasses)
{
  return nsContentUtils::GetElementsByClassName(this, aClasses);
}

bool
ShadowRoot::PrefEnabled()
{
  return Preferences::GetBool("dom.webcomponents.enabled", false);
}