dom/html/nsHTMLContentSink.cpp
author Masayuki Nakano <masayuki@d-toybox.com>
Fri, 19 May 2017 17:49:41 +0900
changeset 407399 b75c111837a802ceb953dba50a3c5a193d53ca22
parent 405203 0788c41e592b476d8261074ff8335e975a713b3a
child 412003 33b0931bbfc03c110d37ea360beec1e1d33db958
child 414672 77af189b5c493e3a4359613604592485627d16cd
permissions -rw-r--r--
Bug 1339543 part 4 Change nsIWidget::ExecuteNativeKeyBinding() to nsIWidget::GetEditCommands() which just retrieves edit commands for the type r=smaug Now, nsIWidget::ExecuteNativeKeyBinding() isn't used by anybody for executing edit commands. Instead, they need array of edit commands for the key combination. So, the method should be renamed to GetEditCommands() and just return edit commands as an array. MozReview-Commit-ID: 4G0B1lJ8Lbe

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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/. */

/**
 * This file is near-OBSOLETE. It is used for about:blank only and for the
 * HTML element factory.
 * Don't bother adding new stuff in this file.
 */

#include "mozilla/ArrayUtils.h"

#include "nsContentSink.h"
#include "nsCOMPtr.h"
#include "nsReadableUtils.h"
#include "nsUnicharUtils.h"
#include "nsIHTMLContentSink.h"
#include "nsIInterfaceRequestor.h"
#include "nsIInterfaceRequestorUtils.h"
#include "nsIURI.h"
#include "nsIContentViewer.h"
#include "mozilla/dom/NodeInfo.h"
#include "mozilla/dom/ScriptLoader.h"
#include "nsToken.h"
#include "nsIAppShell.h"
#include "nsCRT.h"
#include "prtime.h"
#include "mozilla/Logging.h"
#include "nsNodeUtils.h"
#include "nsIContent.h"
#include "mozilla/dom/Element.h"
#include "mozilla/Preferences.h"

#include "nsGenericHTMLElement.h"

#include "nsIDOMDocument.h"
#include "nsIDOMDocumentType.h"
#include "nsIScriptElement.h"

#include "nsIComponentManager.h"
#include "nsIServiceManager.h"

#include "nsGkAtoms.h"
#include "nsContentUtils.h"
#include "nsIChannel.h"
#include "nsIHttpChannel.h"
#include "nsIDocShell.h"
#include "nsIDocument.h"
#include "nsStubDocumentObserver.h"
#include "nsIHTMLDocument.h"
#include "nsIDOMHTMLMapElement.h"
#include "nsICookieService.h"
#include "nsTArray.h"
#include "nsIScriptSecurityManager.h"
#include "nsIPrincipal.h"
#include "nsTextFragment.h"
#include "nsIScriptGlobalObject.h"
#include "nsNameSpaceManager.h"

#include "nsIParserService.h"

#include "nsIStyleSheetLinkingElement.h"
#include "nsITimer.h"
#include "nsError.h"
#include "nsContentPolicyUtils.h"
#include "nsIScriptContext.h"
#include "nsStyleLinkElement.h"

#include "nsWeakReference.h" // nsHTMLElementFactory supports weak references
#include "nsIPrompt.h"
#include "nsLayoutCID.h"
#include "nsIDocShellTreeItem.h"

#include "nsEscape.h"
#include "nsNodeInfoManager.h"
#include "nsContentCreatorFunctions.h"
#include "mozAutoDocUpdate.h"
#include "nsTextNode.h"

using namespace mozilla;
using namespace mozilla::dom;

//----------------------------------------------------------------------

typedef nsGenericHTMLElement*
  (*contentCreatorCallback)(already_AddRefed<mozilla::dom::NodeInfo>&&,
                            FromParser aFromParser);

nsGenericHTMLElement*
NS_NewHTMLNOTUSEDElement(already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo,
                         FromParser aFromParser)
{
  NS_NOTREACHED("The element ctor should never be called");
  return nullptr;
}

#define HTML_TAG(_tag, _classname, _interfacename) NS_NewHTML##_classname##Element,
#define HTML_OTHER(_tag) NS_NewHTMLNOTUSEDElement,
static const contentCreatorCallback sContentCreatorCallbacks[] = {
  NS_NewHTMLUnknownElement,
#include "nsHTMLTagList.h"
#undef HTML_TAG
#undef HTML_OTHER
  NS_NewHTMLUnknownElement
};

class SinkContext;
class HTMLContentSink;

/**
 * This class is near-OBSOLETE. It is used for about:blank only.
 * Don't bother adding new stuff in this file.
 */
class HTMLContentSink : public nsContentSink,
                        public nsIHTMLContentSink
{
public:
  friend class SinkContext;

  HTMLContentSink();

  nsresult Init(nsIDocument* aDoc, nsIURI* aURI, nsISupports* aContainer,
                nsIChannel* aChannel);

  // nsISupports
  NS_DECL_ISUPPORTS_INHERITED
  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(HTMLContentSink, nsContentSink)

  // nsIContentSink
  NS_IMETHOD WillParse(void) override;
  NS_IMETHOD WillBuildModel(nsDTDMode aDTDMode) override;
  NS_IMETHOD DidBuildModel(bool aTerminated) override;
  NS_IMETHOD WillInterrupt(void) override;
  NS_IMETHOD WillResume(void) override;
  NS_IMETHOD SetParser(nsParserBase* aParser) override;
  virtual void FlushPendingNotifications(FlushType aType) override;
  NS_IMETHOD SetDocumentCharset(nsACString& aCharset) override;
  virtual nsISupports *GetTarget() override;
  virtual bool IsScriptExecuting() override;

  // nsIHTMLContentSink
  NS_IMETHOD OpenContainer(ElementType aNodeType) override;
  NS_IMETHOD CloseContainer(ElementType aTag) override;

protected:
  virtual ~HTMLContentSink();

  nsCOMPtr<nsIHTMLDocument> mHTMLDocument;

  // The maximum length of a text run
  int32_t mMaxTextRun;

  RefPtr<nsGenericHTMLElement> mRoot;
  RefPtr<nsGenericHTMLElement> mBody;
  RefPtr<nsGenericHTMLElement> mHead;

  AutoTArray<SinkContext*, 8> mContextStack;
  SinkContext* mCurrentContext;
  SinkContext* mHeadContext;

  // Boolean indicating whether we've seen a <head> tag that might have had
  // attributes once already.
  bool mHaveSeenHead;

  // Boolean indicating whether we've notified insertion of our root content
  // yet.  We want to make sure to only do this once.
  bool mNotifiedRootInsertion;

  nsresult FlushTags() override;

  // Routines for tags that require special handling
  nsresult CloseHTML();
  nsresult OpenBody();
  nsresult CloseBody();

  void CloseHeadContext();

  // nsContentSink overrides
  void UpdateChildCounts() override;

  void NotifyInsert(nsIContent* aContent,
                    nsIContent* aChildContent,
                    int32_t aIndexInContainer);
  void NotifyRootInsertion();
};

class SinkContext
{
public:
  explicit SinkContext(HTMLContentSink* aSink);
  ~SinkContext();

  nsresult Begin(nsHTMLTag aNodeType, nsGenericHTMLElement* aRoot,
                 uint32_t aNumFlushed, int32_t aInsertionPoint);
  nsresult OpenBody();
  nsresult CloseBody();
  nsresult End();

  nsresult GrowStack();
  nsresult FlushTags();

  bool     IsCurrentContainer(nsHTMLTag mType);

  void DidAddContent(nsIContent* aContent);
  void UpdateChildCounts();

private:
  // Function to check whether we've notified for the current content.
  // What this actually does is check whether we've notified for all
  // of the parent's kids.
  bool HaveNotifiedForCurrentContent() const;

public:
  HTMLContentSink* mSink;
  int32_t mNotifyLevel;

  struct Node {
    nsHTMLTag mType;
    nsGenericHTMLElement* mContent;
    uint32_t mNumFlushed;
    int32_t mInsertionPoint;

    nsIContent *Add(nsIContent *child);
  };

  Node* mStack;
  int32_t mStackSize;
  int32_t mStackPos;
};

nsresult
NS_NewHTMLElement(Element** aResult, already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo,
                  FromParser aFromParser, const nsAString* aIs)
{
  *aResult = nullptr;

  RefPtr<mozilla::dom::NodeInfo> nodeInfo = aNodeInfo;

  nsIParserService* parserService = nsContentUtils::GetParserService();
  if (!parserService)
    return NS_ERROR_OUT_OF_MEMORY;

  nsIAtom *name = nodeInfo->NameAtom();

  NS_ASSERTION(nodeInfo->NamespaceEquals(kNameSpaceID_XHTML),
               "Trying to HTML elements that don't have the XHTML namespace");

  int32_t tag = parserService->HTMLCaseSensitiveAtomTagToId(name);

  // Per the Custom Element specification, unknown tags that are valid custom
  // element names should be HTMLElement instead of HTMLUnknownElement.
  bool isCustomElementName = (tag == eHTMLTag_userdefined &&
                              nsContentUtils::IsCustomElementName(name));
  if (isCustomElementName) {
    NS_IF_ADDREF(*aResult = NS_NewHTMLElement(nodeInfo.forget(), aFromParser));
  } else {
    *aResult = CreateHTMLElement(tag, nodeInfo.forget(), aFromParser).take();
  }

  if (!*aResult) {
    return NS_ERROR_OUT_OF_MEMORY;
  }

  if (CustomElementRegistry::IsCustomElementEnabled() &&
      (isCustomElementName || aIs)) {
    nsContentUtils::SetupCustomElement(*aResult, aIs);
  }

  return NS_OK;
}

already_AddRefed<nsGenericHTMLElement>
CreateHTMLElement(uint32_t aNodeType,
                  already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo,
                  FromParser aFromParser)
{
  NS_ASSERTION(aNodeType <= NS_HTML_TAG_MAX ||
               aNodeType == eHTMLTag_userdefined,
               "aNodeType is out of bounds");

  contentCreatorCallback cb = sContentCreatorCallbacks[aNodeType];

  NS_ASSERTION(cb != NS_NewHTMLNOTUSEDElement,
               "Don't know how to construct tag element!");

  RefPtr<nsGenericHTMLElement> result = cb(Move(aNodeInfo), aFromParser);

  return result.forget();
}

//----------------------------------------------------------------------

SinkContext::SinkContext(HTMLContentSink* aSink)
  : mSink(aSink),
    mNotifyLevel(0),
    mStack(nullptr),
    mStackSize(0),
    mStackPos(0)
{
  MOZ_COUNT_CTOR(SinkContext);
}

SinkContext::~SinkContext()
{
  MOZ_COUNT_DTOR(SinkContext);

  if (mStack) {
    for (int32_t i = 0; i < mStackPos; i++) {
      NS_RELEASE(mStack[i].mContent);
    }
    delete [] mStack;
  }
}

nsresult
SinkContext::Begin(nsHTMLTag aNodeType,
                   nsGenericHTMLElement* aRoot,
                   uint32_t aNumFlushed,
                   int32_t aInsertionPoint)
{
  if (mStackSize < 1) {
    nsresult rv = GrowStack();
    if (NS_FAILED(rv)) {
      return rv;
    }
  }

  mStack[0].mType = aNodeType;
  mStack[0].mContent = aRoot;
  mStack[0].mNumFlushed = aNumFlushed;
  mStack[0].mInsertionPoint = aInsertionPoint;
  NS_ADDREF(aRoot);
  mStackPos = 1;

  return NS_OK;
}

bool
SinkContext::IsCurrentContainer(nsHTMLTag aTag)
{
  if (aTag == mStack[mStackPos - 1].mType) {
    return true;
  }

  return false;
}

void
SinkContext::DidAddContent(nsIContent* aContent)
{
  if ((mStackPos == 2) && (mSink->mBody == mStack[1].mContent)) {
    // We just finished adding something to the body
    mNotifyLevel = 0;
  }

  // If we just added content to a node for which
  // an insertion happen, we need to do an immediate
  // notification for that insertion.
  if (0 < mStackPos &&
      mStack[mStackPos - 1].mInsertionPoint != -1 &&
      mStack[mStackPos - 1].mNumFlushed <
      mStack[mStackPos - 1].mContent->GetChildCount()) {
    nsIContent* parent = mStack[mStackPos - 1].mContent;
    int32_t childIndex = mStack[mStackPos - 1].mInsertionPoint - 1;
    NS_ASSERTION(parent->GetChildAt(childIndex) == aContent,
                 "Flushing the wrong child.");
    mSink->NotifyInsert(parent, aContent, childIndex);
    mStack[mStackPos - 1].mNumFlushed = parent->GetChildCount();
  } else if (mSink->IsTimeToNotify()) {
    FlushTags();
  }
}

nsresult
SinkContext::OpenBody()
{
  if (mStackPos <= 0) {
    NS_ERROR("container w/o parent");

    return NS_ERROR_FAILURE;
  }

  nsresult rv;
  if (mStackPos + 1 > mStackSize) {
    rv = GrowStack();
    if (NS_FAILED(rv)) {
      return rv;
    }
  }

    RefPtr<mozilla::dom::NodeInfo> nodeInfo =
      mSink->mNodeInfoManager->GetNodeInfo(nsGkAtoms::body, nullptr,
                                           kNameSpaceID_XHTML,
                                           nsIDOMNode::ELEMENT_NODE);
  NS_ENSURE_TRUE(nodeInfo, NS_ERROR_UNEXPECTED);

  // Make the content object
  RefPtr<nsGenericHTMLElement> body =
    NS_NewHTMLBodyElement(nodeInfo.forget(), FROM_PARSER_NETWORK);
  if (!body) {
    return NS_ERROR_OUT_OF_MEMORY;
  }

  mStack[mStackPos].mType = eHTMLTag_body;
  body.forget(&mStack[mStackPos].mContent);
  mStack[mStackPos].mNumFlushed = 0;
  mStack[mStackPos].mInsertionPoint = -1;
  ++mStackPos;
  mStack[mStackPos - 2].Add(mStack[mStackPos - 1].mContent);

  return NS_OK;
}

bool
SinkContext::HaveNotifiedForCurrentContent() const
{
  if (0 < mStackPos) {
    nsIContent* parent = mStack[mStackPos - 1].mContent;
    return mStack[mStackPos-1].mNumFlushed == parent->GetChildCount();
  }

  return true;
}

nsIContent *
SinkContext::Node::Add(nsIContent *child)
{
  NS_ASSERTION(mContent, "No parent to insert/append into!");
  if (mInsertionPoint != -1) {
    NS_ASSERTION(mNumFlushed == mContent->GetChildCount(),
                 "Inserting multiple children without flushing.");
    mContent->InsertChildAt(child, mInsertionPoint++, false);
  } else {
    mContent->AppendChildTo(child, false);
  }
  return child;
}

nsresult
SinkContext::CloseBody()
{
  NS_ASSERTION(mStackPos > 0,
               "stack out of bounds. wrong context probably!");

  if (mStackPos <= 0) {
    return NS_OK; // Fix crash - Ref. bug 45975 or 45007
  }

  --mStackPos;
  NS_ASSERTION(mStack[mStackPos].mType == eHTMLTag_body,
               "Tag mismatch.  Closing tag on wrong context or something?");

  nsGenericHTMLElement* content = mStack[mStackPos].mContent;

  content->Compact();

  // If we're in a state where we do append notifications as
  // we go up the tree, and we're at the level where the next
  // notification needs to be done, do the notification.
  if (mNotifyLevel >= mStackPos) {
    // Check to see if new content has been added after our last
    // notification

    if (mStack[mStackPos].mNumFlushed < content->GetChildCount()) {
      mSink->NotifyAppend(content, mStack[mStackPos].mNumFlushed);
      mStack[mStackPos].mNumFlushed = content->GetChildCount();
    }

    // Indicate that notification has now happened at this level
    mNotifyLevel = mStackPos - 1;
  }

  DidAddContent(content);
  NS_IF_RELEASE(content);

  return NS_OK;
}

nsresult
SinkContext::End()
{
  for (int32_t i = 0; i < mStackPos; i++) {
    NS_RELEASE(mStack[i].mContent);
  }

  mStackPos = 0;

  return NS_OK;
}

nsresult
SinkContext::GrowStack()
{
  int32_t newSize = mStackSize * 2;
  if (newSize == 0) {
    newSize = 32;
  }

  Node* stack = new Node[newSize];

  if (mStackPos != 0) {
    memcpy(stack, mStack, sizeof(Node) * mStackPos);
    delete [] mStack;
  }

  mStack = stack;
  mStackSize = newSize;

  return NS_OK;
}

/**
 * NOTE!! Forked into nsXMLContentSink. Please keep in sync.
 *
 * Flush all elements that have been seen so far such that
 * they are visible in the tree. Specifically, make sure
 * that they are all added to their respective parents.
 * Also, do notification at the top for all content that
 * has been newly added so that the frame tree is complete.
 */
nsresult
SinkContext::FlushTags()
{
  mSink->mDeferredFlushTags = false;
  bool oldBeganUpdate = mSink->mBeganUpdate;
  uint32_t oldUpdates = mSink->mUpdatesInNotification;

  ++(mSink->mInNotification);
  mSink->mUpdatesInNotification = 0;
  {
    // Scope so we call EndUpdate before we decrease mInNotification
    mozAutoDocUpdate updateBatch(mSink->mDocument, UPDATE_CONTENT_MODEL,
                                 true);
    mSink->mBeganUpdate = true;

    // Start from the base of the stack (growing downward) and do
    // a notification from the node that is closest to the root of
    // tree for any content that has been added.

    // Note that we can start at stackPos == 0 here, because it's the caller's
    // responsibility to handle flushing interactions between contexts (see
    // HTMLContentSink::BeginContext).
    int32_t stackPos = 0;
    bool flushed = false;
    uint32_t childCount;
    nsGenericHTMLElement* content;

    while (stackPos < mStackPos) {
      content = mStack[stackPos].mContent;
      childCount = content->GetChildCount();

      if (!flushed && (mStack[stackPos].mNumFlushed < childCount)) {
        if (mStack[stackPos].mInsertionPoint != -1) {
          // We might have popped the child off our stack already
          // but not notified on it yet, which is why we have to get it
          // directly from its parent node.

          int32_t childIndex = mStack[stackPos].mInsertionPoint - 1;
          nsIContent* child = content->GetChildAt(childIndex);
          // Child not on stack anymore; can't assert it's correct
          NS_ASSERTION(!(mStackPos > (stackPos + 1)) ||
                       (child == mStack[stackPos + 1].mContent),
                       "Flushing the wrong child.");
          mSink->NotifyInsert(content, child, childIndex);
        } else {
          mSink->NotifyAppend(content, mStack[stackPos].mNumFlushed);
        }

        flushed = true;
      }

      mStack[stackPos].mNumFlushed = childCount;
      stackPos++;
    }
    mNotifyLevel = mStackPos - 1;
  }
  --(mSink->mInNotification);

  if (mSink->mUpdatesInNotification > 1) {
    UpdateChildCounts();
  }

  mSink->mUpdatesInNotification = oldUpdates;
  mSink->mBeganUpdate = oldBeganUpdate;

  return NS_OK;
}

/**
 * NOTE!! Forked into nsXMLContentSink. Please keep in sync.
 */
void
SinkContext::UpdateChildCounts()
{
  // Start from the top of the stack (growing upwards) and see if any
  // new content has been appended. If so, we recognize that reflows
  // have been generated for it and we should make sure that no
  // further reflows occur.  Note that we have to include stackPos == 0
  // to properly notify on kids of <html>.
  int32_t stackPos = mStackPos - 1;
  while (stackPos >= 0) {
    Node & node = mStack[stackPos];
    node.mNumFlushed = node.mContent->GetChildCount();

    stackPos--;
  }

  mNotifyLevel = mStackPos - 1;
}

nsresult
NS_NewHTMLContentSink(nsIHTMLContentSink** aResult,
                      nsIDocument* aDoc,
                      nsIURI* aURI,
                      nsISupports* aContainer,
                      nsIChannel* aChannel)
{
  NS_ENSURE_ARG_POINTER(aResult);

  RefPtr<HTMLContentSink> it = new HTMLContentSink();

  nsresult rv = it->Init(aDoc, aURI, aContainer, aChannel);

  NS_ENSURE_SUCCESS(rv, rv);

  *aResult = it;
  NS_ADDREF(*aResult);

  return NS_OK;
}

HTMLContentSink::HTMLContentSink()
  : mMaxTextRun(0)
  , mCurrentContext(nullptr)
  , mHeadContext(nullptr)
  , mHaveSeenHead(false)
  , mNotifiedRootInsertion(false)
{
}

HTMLContentSink::~HTMLContentSink()
{
  if (mNotificationTimer) {
    mNotificationTimer->Cancel();
  }

  int32_t numContexts = mContextStack.Length();

  if (mCurrentContext == mHeadContext && numContexts > 0) {
    // Pop off the second html context if it's not done earlier
    mContextStack.RemoveElementAt(--numContexts);
  }

  int32_t i;
  for (i = 0; i < numContexts; i++) {
    SinkContext* sc = mContextStack.ElementAt(i);
    if (sc) {
      sc->End();
      if (sc == mCurrentContext) {
        mCurrentContext = nullptr;
      }

      delete sc;
    }
  }

  if (mCurrentContext == mHeadContext) {
    mCurrentContext = nullptr;
  }

  delete mCurrentContext;

  delete mHeadContext;
}

NS_IMPL_CYCLE_COLLECTION_CLASS(HTMLContentSink)

NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(HTMLContentSink, nsContentSink)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mHTMLDocument)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mRoot)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mBody)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mHead)
NS_IMPL_CYCLE_COLLECTION_UNLINK_END
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(HTMLContentSink,
                                                  nsContentSink)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mHTMLDocument)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mRoot)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mBody)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mHead)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END

NS_INTERFACE_TABLE_HEAD_CYCLE_COLLECTION_INHERITED(HTMLContentSink)
  NS_INTERFACE_TABLE_BEGIN
    NS_INTERFACE_TABLE_ENTRY(HTMLContentSink, nsIContentSink)
    NS_INTERFACE_TABLE_ENTRY(HTMLContentSink, nsIHTMLContentSink)
  NS_INTERFACE_TABLE_END
NS_INTERFACE_TABLE_TAIL_INHERITING(nsContentSink)

NS_IMPL_ADDREF_INHERITED(HTMLContentSink, nsContentSink)
NS_IMPL_RELEASE_INHERITED(HTMLContentSink, nsContentSink)

nsresult
HTMLContentSink::Init(nsIDocument* aDoc,
                      nsIURI* aURI,
                      nsISupports* aContainer,
                      nsIChannel* aChannel)
{
  NS_ENSURE_TRUE(aContainer, NS_ERROR_NULL_POINTER);

  nsresult rv = nsContentSink::Init(aDoc, aURI, aContainer, aChannel);
  if (NS_FAILED(rv)) {
    return rv;
  }

  aDoc->AddObserver(this);
  mIsDocumentObserver = true;
  mHTMLDocument = do_QueryInterface(aDoc);

  NS_ASSERTION(mDocShell, "oops no docshell!");

  // Changed from 8192 to greatly improve page loading performance on
  // large pages.  See bugzilla bug 77540.
  mMaxTextRun = Preferences::GetInt("content.maxtextrun", 8191);

  RefPtr<mozilla::dom::NodeInfo> nodeInfo;
  nodeInfo = mNodeInfoManager->GetNodeInfo(nsGkAtoms::html, nullptr,
                                           kNameSpaceID_XHTML,
                                           nsIDOMNode::ELEMENT_NODE);

  // Make root part
  mRoot = NS_NewHTMLHtmlElement(nodeInfo.forget());
  if (!mRoot) {
    return NS_ERROR_OUT_OF_MEMORY;
  }

  NS_ASSERTION(mDocument->GetChildCount() == 0,
               "Document should have no kids here!");
  rv = mDocument->AppendChildTo(mRoot, false);
  NS_ENSURE_SUCCESS(rv, rv);

  // Make head part
  nodeInfo = mNodeInfoManager->GetNodeInfo(nsGkAtoms::head,
                                           nullptr, kNameSpaceID_XHTML,
                                           nsIDOMNode::ELEMENT_NODE);

  mHead = NS_NewHTMLHeadElement(nodeInfo.forget());
  if (NS_FAILED(rv)) {
    return NS_ERROR_OUT_OF_MEMORY;
  }

  mRoot->AppendChildTo(mHead, false);

  mCurrentContext = new SinkContext(this);
  mCurrentContext->Begin(eHTMLTag_html, mRoot, 0, -1);
  mContextStack.AppendElement(mCurrentContext);

  return NS_OK;
}

NS_IMETHODIMP
HTMLContentSink::WillParse(void)
{
  return WillParseImpl();
}

NS_IMETHODIMP
HTMLContentSink::WillBuildModel(nsDTDMode aDTDMode)
{
  WillBuildModelImpl();

  if (mHTMLDocument) {
    nsCompatibility mode = eCompatibility_NavQuirks;
    switch (aDTDMode) {
      case eDTDMode_full_standards:
        mode = eCompatibility_FullStandards;
        break;
      case eDTDMode_almost_standards:
        mode = eCompatibility_AlmostStandards;
        break;
      default:
        break;
    }
    mHTMLDocument->SetCompatibilityMode(mode);
  }

  // Notify document that the load is beginning
  mDocument->BeginLoad();

  return NS_OK;
}

NS_IMETHODIMP
HTMLContentSink::DidBuildModel(bool aTerminated)
{
  DidBuildModelImpl(aTerminated);

  // Reflow the last batch of content
  if (mBody) {
    mCurrentContext->FlushTags();
  } else if (!mLayoutStarted) {
    // We never saw the body, and layout never got started. Force
    // layout *now*, to get an initial reflow.
    // NOTE: only force the layout if we are NOT destroying the
    // docshell. If we are destroying it, then starting layout will
    // likely cause us to crash, or at best waste a lot of time as we
    // are just going to tear it down anyway.
    bool bDestroying = true;
    if (mDocShell) {
      mDocShell->IsBeingDestroyed(&bDestroying);
    }

    if (!bDestroying) {
      StartLayout(false);
    }
  }

  ScrollToRef();

  // Make sure we no longer respond to document mutations.  We've flushed all
  // our notifications out, so there's no need to do anything else here.

  // XXXbz I wonder whether we could End() our contexts here too, or something,
  // just to make sure we no longer notify...  Or is the mIsDocumentObserver
  // thing sufficient?
  mDocument->RemoveObserver(this);
  mIsDocumentObserver = false;

  mDocument->EndLoad();

  DropParserAndPerfHint();

  return NS_OK;
}

NS_IMETHODIMP
HTMLContentSink::SetParser(nsParserBase* aParser)
{
  NS_PRECONDITION(aParser, "Should have a parser here!");
  mParser = aParser;
  return NS_OK;
}

nsresult
HTMLContentSink::CloseHTML()
{
  if (mHeadContext) {
    if (mCurrentContext == mHeadContext) {
      uint32_t numContexts = mContextStack.Length();

      // Pop off the second html context if it's not done earlier
      mCurrentContext = mContextStack.ElementAt(--numContexts);
      mContextStack.RemoveElementAt(numContexts);
    }

    mHeadContext->End();

    delete mHeadContext;
    mHeadContext = nullptr;
  }

  return NS_OK;
}

nsresult
HTMLContentSink::OpenBody()
{
  CloseHeadContext();  // do this just in case if the HEAD was left open!

  // if we already have a body we're done
  if (mBody) {
    return NS_OK;
  }

  nsresult rv = mCurrentContext->OpenBody();

  if (NS_FAILED(rv)) {
    return rv;
  }

  mBody = mCurrentContext->mStack[mCurrentContext->mStackPos - 1].mContent;

  if (mCurrentContext->mStackPos > 1) {
    int32_t parentIndex    = mCurrentContext->mStackPos - 2;
    nsGenericHTMLElement *parent = mCurrentContext->mStack[parentIndex].mContent;
    int32_t numFlushed     = mCurrentContext->mStack[parentIndex].mNumFlushed;
    int32_t childCount = parent->GetChildCount();
    NS_ASSERTION(numFlushed < childCount, "Already notified on the body?");

    int32_t insertionPoint =
      mCurrentContext->mStack[parentIndex].mInsertionPoint;

    // XXX: I have yet to see a case where numFlushed is non-zero and
    // insertionPoint is not -1, but this code will try to handle
    // those cases too.

    uint32_t oldUpdates = mUpdatesInNotification;
    mUpdatesInNotification = 0;
    if (insertionPoint != -1) {
      NotifyInsert(parent, mBody, insertionPoint - 1);
    } else {
      NotifyAppend(parent, numFlushed);
    }
    mCurrentContext->mStack[parentIndex].mNumFlushed = childCount;
    if (mUpdatesInNotification > 1) {
      UpdateChildCounts();
    }
    mUpdatesInNotification = oldUpdates;
  }

  StartLayout(false);

  return NS_OK;
}

nsresult
HTMLContentSink::CloseBody()
{
  // Flush out anything that's left
  mCurrentContext->FlushTags();
  mCurrentContext->CloseBody();

  return NS_OK;
}

NS_IMETHODIMP
HTMLContentSink::OpenContainer(ElementType aElementType)
{
  nsresult rv = NS_OK;

  switch (aElementType) {
    case eBody:
      rv = OpenBody();
      break;
    case eHTML:
      if (mRoot) {
        // If we've already hit this code once, then we're done
        if (!mNotifiedRootInsertion) {
          NotifyRootInsertion();
        }
        ProcessOfflineManifest(mRoot);
      }
      break;
  }

  return rv;
}

NS_IMETHODIMP
HTMLContentSink::CloseContainer(const ElementType aTag)
{
  nsresult rv = NS_OK;

  switch (aTag) {
    case eBody:
      rv = CloseBody();
      break;
    case eHTML:
      rv = CloseHTML();
      break;
  }

  return rv;
}

NS_IMETHODIMP
HTMLContentSink::WillInterrupt()
{
  return WillInterruptImpl();
}

NS_IMETHODIMP
HTMLContentSink::WillResume()
{
  return WillResumeImpl();
}

void
HTMLContentSink::CloseHeadContext()
{
  if (mCurrentContext) {
    if (!mCurrentContext->IsCurrentContainer(eHTMLTag_head))
      return;

    mCurrentContext->FlushTags();
  }

  if (!mContextStack.IsEmpty())
  {
    uint32_t n = mContextStack.Length() - 1;
    mCurrentContext = mContextStack.ElementAt(n);
    mContextStack.RemoveElementAt(n);
  }
}

void
HTMLContentSink::NotifyInsert(nsIContent* aContent,
                              nsIContent* aChildContent,
                              int32_t aIndexInContainer)
{
  if (aContent && aContent->GetUncomposedDoc() != mDocument) {
    // aContent is not actually in our document anymore.... Just bail out of
    // here; notifying on our document for this insert would be wrong.
    return;
  }

  mInNotification++;

  {
    // Scope so we call EndUpdate before we decrease mInNotification
    MOZ_AUTO_DOC_UPDATE(mDocument, UPDATE_CONTENT_MODEL, !mBeganUpdate);
    nsNodeUtils::ContentInserted(NODE_FROM(aContent, mDocument),
                                 aChildContent, aIndexInContainer);
    mLastNotificationTime = PR_Now();
  }

  mInNotification--;
}

void
HTMLContentSink::NotifyRootInsertion()
{
  NS_PRECONDITION(!mNotifiedRootInsertion, "Double-notifying on root?");
  NS_ASSERTION(!mLayoutStarted,
               "How did we start layout without notifying on root?");
  // Now make sure to notify that we have now inserted our root.  If
  // there has been no initial reflow yet it'll be a no-op, but if
  // there has been one we need this to get its frames constructed.
  // Note that if mNotifiedRootInsertion is true we don't notify here,
  // since that just means there are multiple <html> tags in the
  // document; in those cases we just want to put all the attrs on one
  // tag.
  mNotifiedRootInsertion = true;
  int32_t index = mDocument->IndexOf(mRoot);
  NS_ASSERTION(index != -1, "mRoot not child of document?");
  NotifyInsert(nullptr, mRoot, index);

  // Now update the notification information in all our
  // contexts, since we just inserted the root and notified on
  // our whole tree
  UpdateChildCounts();
}

void
HTMLContentSink::UpdateChildCounts()
{
  uint32_t numContexts = mContextStack.Length();
  for (uint32_t i = 0; i < numContexts; i++) {
    SinkContext* sc = mContextStack.ElementAt(i);

    sc->UpdateChildCounts();
  }

  mCurrentContext->UpdateChildCounts();
}

void
HTMLContentSink::FlushPendingNotifications(FlushType aType)
{
  // Only flush tags if we're not doing the notification ourselves
  // (since we aren't reentrant)
  if (!mInNotification) {
    // Only flush if we're still a document observer (so that our child counts
    // should be correct).
    if (mIsDocumentObserver) {
      if (aType >= FlushType::ContentAndNotify) {
        FlushTags();
      }
    }
    if (aType >= FlushType::InterruptibleLayout) {
      // Make sure that layout has started so that the reflow flush
      // will actually happen.
      StartLayout(true);
    }
  }
}

nsresult
HTMLContentSink::FlushTags()
{
  if (!mNotifiedRootInsertion) {
    NotifyRootInsertion();
    return NS_OK;
  }

  return mCurrentContext ? mCurrentContext->FlushTags() : NS_OK;
}

NS_IMETHODIMP
HTMLContentSink::SetDocumentCharset(nsACString& aCharset)
{
  MOZ_ASSERT_UNREACHABLE("<meta charset> case doesn't occur with about:blank");
  return NS_ERROR_NOT_IMPLEMENTED;
}

nsISupports *
HTMLContentSink::GetTarget()
{
  return mDocument;
}

bool
HTMLContentSink::IsScriptExecuting()
{
  return IsScriptExecutingImpl();
}