editor/libeditor/HTMLEditor.cpp
author Masayuki Nakano <masayuki@d-toybox.com>
Mon, 13 Aug 2018 05:16:10 +0000
changeset 486270 50e4f06ac01a1f6dc187ef6ea23226e551f6f2a0
parent 485306 260bf1050ee206a918b45ff5b0280fe1ee8e9979
child 486324 674c721d44fee8c4edd243312cbc73f81122e5d0
permissions -rw-r--r--
Bug 1482013 - Create HTMLEditor::SetInlinePropertyInternal() for internal use r=m_kato For making it possible to distinguish if SetInlineProperty() is called by outer class or the editor itself, this patch creates SetInlinePropertyInternal(). Additionally, this makes the first argument of SetInlineProperty() from nsAtom* to nsAtom& since it's not nullable. Differential Revision: https://phabricator.services.mozilla.com/D2999

/* -*- 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/HTMLEditor.h"

#include "mozilla/ComposerCommandsUpdater.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/EditAction.h"
#include "mozilla/EditorDOMPoint.h"
#include "mozilla/EventStates.h"
#include "mozilla/mozInlineSpellChecker.h"
#include "mozilla/Telemetry.h"
#include "mozilla/TextEvents.h"

#include "nsCRT.h"

#include "nsUnicharUtils.h"

#include "HTMLEditorEventListener.h"
#include "HTMLEditRules.h"
#include "HTMLEditUtils.h"
#include "HTMLURIRefObject.h"
#include "TextEditUtils.h"
#include "TypeInState.h"

#include "nsHTMLDocument.h"
#include "nsIDocumentInlines.h"
#include "nsISelectionController.h"
#include "nsILinkHandler.h"
#include "nsIInlineSpellChecker.h"

#include "mozilla/css/Loader.h"

#include "nsIContent.h"
#include "nsIContentIterator.h"
#include "nsIMutableArray.h"
#include "nsContentUtils.h"
#include "nsIDocumentEncoder.h"
#include "nsGenericHTMLElement.h"
#include "nsIPresShell.h"
#include "nsPresContext.h"
#include "nsFocusManager.h"
#include "nsPIDOMWindow.h"

// netwerk
#include "nsIURI.h"
#include "nsNetUtil.h"

// Misc
#include "mozilla/EditorUtils.h"
#include "HTMLEditorObjectResizerUtils.h"
#include "TextEditorTest.h"
#include "WSRunObject.h"
#include "nsGkAtoms.h"
#include "nsIWidget.h"

#include "nsIFrame.h"
#include "mozilla/dom/Selection.h"
#include "mozilla/dom/DocumentFragment.h"
#include "mozilla/dom/Element.h"
#include "mozilla/dom/Event.h"
#include "mozilla/dom/EventTarget.h"
#include "mozilla/dom/HTMLBodyElement.h"
#include "nsElementTable.h"
#include "nsTextFragment.h"
#include "nsContentList.h"
#include "mozilla/StyleSheet.h"
#include "mozilla/StyleSheetInlines.h"

namespace mozilla {

using namespace dom;
using namespace widget;

const char16_t kNBSP = 160;

// Some utilities to handle overloading of "A" tag for link and named anchor.
static bool
IsLinkTag(const nsString& s)
{
  return s.EqualsIgnoreCase("href");
}

static bool
IsNamedAnchorTag(const nsString& s)
{
  return s.EqualsIgnoreCase("anchor") || s.EqualsIgnoreCase("namedanchor");
}

template EditorDOMPoint
HTMLEditor::InsertNodeIntoProperAncestorWithTransaction(
              nsIContent& aNode,
              const EditorDOMPoint& aPointToInsert,
              SplitAtEdges aSplitAtEdges);
template EditorDOMPoint
HTMLEditor::InsertNodeIntoProperAncestorWithTransaction(
              nsIContent& aNode,
              const EditorRawDOMPoint& aPointToInsert,
              SplitAtEdges aSplitAtEdges);

HTMLEditor::HTMLEditor()
  : mCRInParagraphCreatesParagraph(false)
  , mCSSAware(false)
  , mSelectedCellIndex(0)
  , mHasShownResizers(false)
  , mIsObjectResizingEnabled(true)
  , mIsResizing(false)
  , mPreserveRatio(false)
  , mResizedObjectIsAnImage(false)
  , mIsAbsolutelyPositioningEnabled(true)
  , mResizedObjectIsAbsolutelyPositioned(false)
  , mHasShownGrabber(false)
  , mGrabberClicked(false)
  , mIsMoving(false)
  , mSnapToGridEnabled(false)
  , mHasShownInlineTableEditor(false)
  , mIsInlineTableEditingEnabled(true)
  , mOriginalX(0)
  , mOriginalY(0)
  , mResizedObjectX(0)
  , mResizedObjectY(0)
  , mResizedObjectWidth(0)
  , mResizedObjectHeight(0)
  , mResizedObjectMarginLeft(0)
  , mResizedObjectMarginTop(0)
  , mResizedObjectBorderLeft(0)
  , mResizedObjectBorderTop(0)
  , mXIncrementFactor(0)
  , mYIncrementFactor(0)
  , mWidthIncrementFactor(0)
  , mHeightIncrementFactor(0)
  , mResizerUsedCount(0)
  , mGrabberUsedCount(0)
  , mInlineTableEditorUsedCount(0)
  , mInfoXIncrement(20)
  , mInfoYIncrement(20)
  , mPositionedObjectX(0)
  , mPositionedObjectY(0)
  , mPositionedObjectWidth(0)
  , mPositionedObjectHeight(0)
  , mPositionedObjectMarginLeft(0)
  , mPositionedObjectMarginTop(0)
  , mPositionedObjectBorderLeft(0)
  , mPositionedObjectBorderTop(0)
  , mGridSize(0)
  , mDefaultParagraphSeparator(
      Preferences::GetBool("editor.use_div_for_default_newlines", true)
      ? ParagraphSeparator::div : ParagraphSeparator::br)
{
  mIsHTMLEditorClass = true;
}

HTMLEditor::~HTMLEditor()
{
  if (mRules && mRules->AsHTMLEditRules()) {
    mRules->AsHTMLEditRules()->EndListeningToEditSubActions();
  }

  mTypeInState = nullptr;

  if (mLinkHandler && IsInitialized()) {
    nsCOMPtr<nsIPresShell> ps = GetPresShell();

    if (ps && ps->GetPresContext()) {
      ps->GetPresContext()->SetLinkHandler(mLinkHandler);
    }
  }

  RemoveEventListeners();

  HideAnonymousEditingUIs();

  Telemetry::Accumulate(
    Telemetry::HTMLEDITORS_WITH_RESIZERS,
    mHasShownResizers ? 1 : 0);
  if (mHasShownResizers) {
    Telemetry::Accumulate(
      Telemetry::HTMLEDITORS_WHOSE_RESIZERS_USED_BY_USER,
      mResizerUsedCount);
  }
  Telemetry::Accumulate(
    Telemetry::HTMLEDITORS_WITH_ABSOLUTE_POSITIONER,
    mHasShownGrabber ? 1 : 0);
  if (mHasShownGrabber) {
    Telemetry::Accumulate(
      Telemetry::HTMLEDITORS_WHOSE_ABSOLUTE_POSITIONER_USED_BY_USER,
      mGrabberUsedCount);
  }
  Telemetry::Accumulate(
    Telemetry::HTMLEDITORS_WITH_INLINE_TABLE_EDITOR,
    mHasShownInlineTableEditor ? 1 : 0);
  if (mHasShownInlineTableEditor) {
    Telemetry::Accumulate(
      Telemetry::HTMLEDITORS_WHOSE_INLINE_TABLE_EDITOR_USED_BY_USER,
      mInlineTableEditorUsedCount);
  }
}

void
HTMLEditor::HideAnonymousEditingUIs()
{
  if (mAbsolutelyPositionedObject) {
    HideGrabber();
  }
  if (mInlineEditedCell) {
    HideInlineTableEditingUI();
  }
  if (mResizedObject) {
    HideResizers();
  }
}

NS_IMPL_CYCLE_COLLECTION_CLASS(HTMLEditor)

NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(HTMLEditor, TextEditor)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mTypeInState)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mComposerCommandsUpdater)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mStyleSheets)

  tmp->HideAnonymousEditingUIs();

  NS_IMPL_CYCLE_COLLECTION_UNLINK(mLinkHandler)
NS_IMPL_CYCLE_COLLECTION_UNLINK_END

NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(HTMLEditor, TextEditor)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mTypeInState)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mComposerCommandsUpdater)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mStyleSheets)

  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mTopLeftHandle)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mTopHandle)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mTopRightHandle)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mLeftHandle)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mRightHandle)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mBottomLeftHandle)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mBottomHandle)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mBottomRightHandle)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mActivatedHandle)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mResizingShadow)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mResizingInfo)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mResizedObject)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mMouseMotionListenerP)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mResizeEventListenerP)

  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mAbsolutelyPositionedObject)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mGrabber)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mPositioningShadow)

  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mInlineEditedCell)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mAddColumnBeforeButton)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mRemoveColumnButton)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mAddColumnAfterButton)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mAddRowBeforeButton)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mRemoveRowButton)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mAddRowAfterButton)

  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mLinkHandler)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END

NS_IMPL_ADDREF_INHERITED(HTMLEditor, EditorBase)
NS_IMPL_RELEASE_INHERITED(HTMLEditor, EditorBase)

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(HTMLEditor)
  NS_INTERFACE_MAP_ENTRY(nsIHTMLEditor)
  NS_INTERFACE_MAP_ENTRY(nsIHTMLObjectResizer)
  NS_INTERFACE_MAP_ENTRY(nsIHTMLAbsPosEditor)
  NS_INTERFACE_MAP_ENTRY(nsIHTMLInlineTableEditor)
  NS_INTERFACE_MAP_ENTRY(nsITableEditor)
  NS_INTERFACE_MAP_ENTRY(nsIEditorStyleSheets)
  NS_INTERFACE_MAP_ENTRY(nsIMutationObserver)
  NS_INTERFACE_MAP_ENTRY(nsIEditorMailSupport)
NS_INTERFACE_MAP_END_INHERITING(TextEditor)

nsresult
HTMLEditor::Init(nsIDocument& aDoc,
                 Element* aRoot,
                 nsISelectionController* aSelCon,
                 uint32_t aFlags,
                 const nsAString& aInitialValue)
{
  MOZ_ASSERT(aInitialValue.IsEmpty(), "Non-empty initial values not supported");

  nsresult rulesRv = NS_OK;

  {
    // block to scope AutoEditInitRulesTrigger
    AutoEditInitRulesTrigger rulesTrigger(this, rulesRv);

    // Init the plaintext editor
    nsresult rv = TextEditor::Init(aDoc, aRoot, nullptr, aFlags, aInitialValue);
    if (NS_FAILED(rv)) {
      return rv;
    }

    // Init mutation observer
    aDoc.AddMutationObserverUnlessExists(this);

    if (!mRootElement) {
      UpdateRootElement();
    }

    // disable Composer-only features
    if (IsMailEditor()) {
      SetAbsolutePositioningEnabled(false);
      SetSnapToGridEnabled(false);
    }

    // Init the HTML-CSS utils
    mCSSEditUtils = MakeUnique<CSSEditUtils>(this);

    // disable links
    nsCOMPtr<nsIPresShell> presShell = GetPresShell();
    NS_ENSURE_TRUE(presShell, NS_ERROR_FAILURE);
    nsPresContext *context = presShell->GetPresContext();
    NS_ENSURE_TRUE(context, NS_ERROR_NULL_POINTER);
    if (!IsPlaintextEditor() && !IsInteractionAllowed()) {
      mLinkHandler = context->GetLinkHandler();
      context->SetLinkHandler(nullptr);
    }

    // init the type-in state
    mTypeInState = new TypeInState();

    if (!IsInteractionAllowed()) {
      // ignore any errors from this in case the file is missing
      AddOverrideStyleSheet(NS_LITERAL_STRING("resource://gre/res/EditorOverride.css"));
    }
  }
  NS_ENSURE_SUCCESS(rulesRv, rulesRv);

  return NS_OK;
}

void
HTMLEditor::PreDestroy(bool aDestroyingFrames)
{
  if (mDidPreDestroy) {
    return;
  }

  nsCOMPtr<nsIDocument> document = GetDocument();
  if (document) {
    document->RemoveMutationObserver(this);
  }

  while (!mStyleSheetURLs.IsEmpty()) {
    RemoveOverrideStyleSheet(mStyleSheetURLs[0]);
  }

  // Clean up after our anonymous content -- we don't want these nodes to
  // stay around (which they would, since the frames have an owning reference).
  HideAnonymousEditingUIs();

  EditorBase::PreDestroy(aDestroyingFrames);
}

NS_IMETHODIMP
HTMLEditor::NotifySelectionChanged(nsIDocument* aDocument,
                                   Selection* aSelection,
                                   int16_t aReason)
{
  if (NS_WARN_IF(!aDocument) || NS_WARN_IF(!aSelection)) {
    return NS_ERROR_INVALID_ARG;
  }

  if (mTypeInState) {
    RefPtr<TypeInState> typeInState = mTypeInState;
    typeInState->OnSelectionChange(*aSelection);

    // We used a class which derived from nsISelectionListener to call
    // HTMLEditor::CheckSelectionStateForAnonymousButtons().  The lifetime of
    // the class was exactly same as mTypeInState.  So, call it only when
    // mTypeInState is not nullptr.
    if ((aReason & (nsISelectionListener::MOUSEDOWN_REASON |
                    nsISelectionListener::KEYPRESS_REASON |
                    nsISelectionListener::SELECTALL_REASON)) && aSelection) {
      // the selection changed and we need to check if we have to
      // hide and/or redisplay resizing handles
      // FYI: This is an XPCOM method.  So, the caller, Selection, guarantees
      //      the lifetime of this instance.  So, don't need to grab this with
      //      local variable.
      CheckSelectionStateForAnonymousButtons(aSelection);
    }
  }

  if (mComposerCommandsUpdater) {
    RefPtr<ComposerCommandsUpdater> updater = mComposerCommandsUpdater;
    updater->OnSelectionChange();
  }

  return EditorBase::NotifySelectionChanged(aDocument, aSelection, aReason);
}

void
HTMLEditor::UpdateRootElement()
{
  // Use the HTML documents body element as the editor root if we didn't
  // get a root element during initialization.

  mRootElement = GetBodyElement();
  if (!mRootElement) {
    nsCOMPtr<nsIDocument> doc = GetDocument();
    if (doc) {
      // If there is no HTML body element,
      // we should use the document root element instead.
      mRootElement = doc->GetDocumentElement();
    }
    // else leave it null, for lack of anything better.
  }
}

already_AddRefed<nsIContent>
HTMLEditor::FindSelectionRoot(nsINode* aNode)
{
  if (NS_WARN_IF(!aNode)) {
    return nullptr;
  }

  MOZ_ASSERT(aNode->IsDocument() || aNode->IsContent(),
             "aNode must be content or document node");

  nsCOMPtr<nsIDocument> doc = aNode->GetComposedDoc();
  if (!doc) {
    return nullptr;
  }

  nsCOMPtr<nsIContent> content;
  if (aNode->IsInUncomposedDoc() &&
      (doc->HasFlag(NODE_IS_EDITABLE) || !aNode->IsContent())) {
    content = doc->GetRootElement();
    return content.forget();
  }
  content = aNode->AsContent();

  // XXX If we have readonly flag, shouldn't return the element which has
  // contenteditable="true"?  However, such case isn't there without chrome
  // permission script.
  if (IsReadonly()) {
    // We still want to allow selection in a readonly editor.
    content = do_QueryInterface(GetRoot());
    return content.forget();
  }

  if (!content->HasFlag(NODE_IS_EDITABLE)) {
    // If the content is in read-write state but is not editable itself,
    // return it as the selection root.
    if (content->IsElement() &&
        content->AsElement()->State().HasState(NS_EVENT_STATE_MOZ_READWRITE)) {
      return content.forget();
    }
    return nullptr;
  }

  // For non-readonly editors we want to find the root of the editable subtree
  // containing aContent.
  content = content->GetEditingHost();
  return content.forget();
}

void
HTMLEditor::CreateEventListeners()
{
  // Don't create the handler twice
  if (!mEventListener) {
    mEventListener = new HTMLEditorEventListener();
  }
}

nsresult
HTMLEditor::InstallEventListeners()
{
  if (NS_WARN_IF(!IsInitialized()) || NS_WARN_IF(!mEventListener)) {
    return NS_ERROR_NOT_INITIALIZED;
  }

  // NOTE: HTMLEditor doesn't need to initialize mEventTarget here because
  // the target must be document node and it must be referenced as weak pointer.

  HTMLEditorEventListener* listener =
    reinterpret_cast<HTMLEditorEventListener*>(mEventListener.get());
  return listener->Connect(this);
}

void
HTMLEditor::RemoveEventListeners()
{
  if (!IsInitialized()) {
    return;
  }

  RefPtr<EventTarget> target = GetDOMEventTarget();

  if (target) {
    // Both mMouseMotionListenerP and mResizeEventListenerP can be
    // registerd with other targets than the DOM event receiver that
    // we can reach from here. But nonetheless, unregister the event
    // listeners with the DOM event reveiver (if it's registerd with
    // other targets, it'll get unregisterd once the target goes
    // away).

    if (mMouseMotionListenerP) {
      // mMouseMotionListenerP might be registerd either as bubbling or
      // capturing, unregister by both.
      target->RemoveEventListener(NS_LITERAL_STRING("mousemove"),
                                  mMouseMotionListenerP, false);
      target->RemoveEventListener(NS_LITERAL_STRING("mousemove"),
                                  mMouseMotionListenerP, true);
    }

    if (mResizeEventListenerP) {
      target->RemoveEventListener(NS_LITERAL_STRING("resize"),
                                  mResizeEventListenerP, false);
    }
  }

  mMouseMotionListenerP = nullptr;
  mResizeEventListenerP = nullptr;

  TextEditor::RemoveEventListeners();
}

NS_IMETHODIMP
HTMLEditor::SetFlags(uint32_t aFlags)
{
  nsresult rv = TextEditor::SetFlags(aFlags);
  NS_ENSURE_SUCCESS(rv, rv);

  // Sets mCSSAware to correspond to aFlags. This toggles whether CSS is
  // used to style elements in the editor. Note that the editor is only CSS
  // aware by default in Composer and in the mail editor.
  mCSSAware = !NoCSS() && !IsMailEditor();

  return NS_OK;
}

nsresult
HTMLEditor::InitRules()
{
  if (!mRules) {
    // instantiate the rules for the html editor
    mRules = new HTMLEditRules();
  }
  return mRules->Init(this);
}

NS_IMETHODIMP
HTMLEditor::BeginningOfDocument()
{
  return MaybeCollapseSelectionAtFirstEditableNode(false);
}

void
HTMLEditor::InitializeSelectionAncestorLimit(Selection& aSelection,
                                             nsIContent& aAncestorLimit)
{
  // Hack for initializing selection.
  // HTMLEditor::MaybeCollapseSelectionAtFirstEditableNode() will try to
  // collapse selection at first editable text node or inline element which
  // cannot have text nodes as its children.  However, selection has already
  // set into the new editing host by user, we should not change it.  For
  // solving this issue, we should do nothing if selection range is in active
  // editing host except it's not collapsed at start of the editing host since
  // aSelection.SetAncestorLimiter(aAncestorLimit) will collapse selection
  // at start of the new limiter if focus node of aSelection is outside of the
  // editing host.  However, we need to check here if selection is already
  // collapsed at start of the editing host because it's possible JS to do it.
  // In such case, we should not modify selection with calling
  // MaybeCollapseSelectionAtFirstEditableNode().

  // Basically, we should try to collapse selection at first editable node
  // in HTMLEditor.
  bool tryToCollapseSelectionAtFirstEditableNode = true;
  if (aSelection.RangeCount() == 1 && aSelection.IsCollapsed()) {
    Element* editingHost = GetActiveEditingHost();
    nsRange* range = aSelection.GetRangeAt(0);
    if (range->GetStartContainer() == editingHost &&
        !range->StartOffset()) {
      // JS or user operation has already collapsed selection at start of
      // the editing host.  So, we don't need to try to change selection
      // in this case.
      tryToCollapseSelectionAtFirstEditableNode = false;
    }
  }

  EditorBase::InitializeSelectionAncestorLimit(aSelection, aAncestorLimit);

  // XXX Do we need to check if we still need to change selection?  E.g.,
  //     we could have already lost focus while we're changing the ancestor
  //     limiter because it may causes "selectionchange" event.
  if (tryToCollapseSelectionAtFirstEditableNode) {
    MaybeCollapseSelectionAtFirstEditableNode(true);
  }
}

nsresult
HTMLEditor::MaybeCollapseSelectionAtFirstEditableNode(
              bool aIgnoreIfSelectionInEditingHost)
{
  // XXX Why doesn't this check if the document is alive?
  if (!IsInitialized()) {
    return NS_ERROR_NOT_INITIALIZED;
  }

  RefPtr<Selection> selection = GetSelection();
  if (NS_WARN_IF(!selection)) {
    return NS_ERROR_NOT_INITIALIZED;
  }

  // Use editing host.  If you use root element here, selection may be
  // moved to <head> element, e.g., if there is a text node in <script>
  // element.  So, we should use active editing host.
  RefPtr<Element> editingHost = GetActiveEditingHost();
  if (NS_WARN_IF(!editingHost)) {
    return NS_OK;
  }

  // If selection range is already in the editing host and the range is not
  // start of the editing host, we shouldn't reset selection.  E.g., window
  // is activated when the editor had focus before inactivated.
  if (aIgnoreIfSelectionInEditingHost && selection->RangeCount() == 1) {
    nsRange* range = selection->GetRangeAt(0);
    if (!range->Collapsed() ||
        range->GetStartContainer() != editingHost.get() ||
        range->StartOffset()) {
      return NS_OK;
    }
  }

  // Find first editable and visible node.
  EditorRawDOMPoint pointToPutCaret(editingHost, 0);
  for (;;) {
    WSRunObject wsObj(this, pointToPutCaret.GetContainer(),
                      pointToPutCaret.Offset());
    int32_t visOffset = 0;
    WSType visType;
    nsCOMPtr<nsINode> visNode;
    wsObj.NextVisibleNode(pointToPutCaret,
                          address_of(visNode), &visOffset, &visType);

    // If we meet a non-editable node first, we should move caret to start of
    // the editing host (perhaps, user may want to insert something before
    // the first non-editable node? Chromium behaves so).
    if (visNode && !visNode->IsEditable()) {
      pointToPutCaret.Set(editingHost, 0);
      break;
    }

    // WSRunObject::NextVisibleNode() returns WSType::special and the "special"
    // node when it meets empty inline element.  In this case, we should go to
    // next sibling.  For example, if current editor is:
    // <div contenteditable><span></span><b><br></b></div>
    // then, we should put caret at the <br> element.  So, let's check if
    // found node is an empty inline container element.
    if (visType == WSType::special && visNode &&
        TagCanContainTag(*visNode->NodeInfo()->NameAtom(),
                         *nsGkAtoms::textTagName)) {
      pointToPutCaret.Set(visNode);
      DebugOnly<bool> advanced = pointToPutCaret.AdvanceOffset();
      NS_WARNING_ASSERTION(advanced,
        "Failed to advance offset from found empty inline container element");
      continue;
    }

    // If there is editable and visible text node, move caret at start of it.
    if (visType == WSType::normalWS || visType == WSType::text) {
      pointToPutCaret.Set(visNode, visOffset);
      break;
    }

    // If there is editable <br> or something inline special element like
    // <img>, <input>, etc, move caret before it.
    if (visType == WSType::br || visType == WSType::special) {
      pointToPutCaret.Set(visNode);
      break;
    }

    // If there is no visible/editable node except another block element in
    // current editing host, we should move caret to very first of the editing
    // host.
    // XXX This may not make sense, but Chromium behaves so.  Therefore, the
    //     reason why we do this is just compatibility with Chromium.
    if (visType != WSType::otherBlock) {
      pointToPutCaret.Set(editingHost, 0);
      break;
    }

    // By definition of WSRunObject, a block element terminates a whitespace
    // run. That is, although we are calling a method that is named
    // "NextVisibleNode", the node returned might not be visible/editable!

    // However, we were given a block that is not a container.  Since the
    // block can not contain anything that's visible, such a block only
    // makes sense if it is visible by itself, like a <hr>.  We want to
    // place the caret in front of that block.
    if (!IsContainer(visNode)) {
      pointToPutCaret.Set(visNode);
      break;
    }

    // If the given block does not contain any visible/editable items, we want
    // to skip it and continue our search.
    bool isEmptyBlock;
    if (NS_SUCCEEDED(IsEmptyNode(visNode, &isEmptyBlock)) && isEmptyBlock) {
      // Skip the empty block
      pointToPutCaret.Set(visNode);
      DebugOnly<bool> advanced = pointToPutCaret.AdvanceOffset();
      NS_WARNING_ASSERTION(advanced,
        "Failed to advance offset from the found empty block node");
    } else {
      pointToPutCaret.Set(visNode, 0);
    }
  }
  return selection->Collapse(pointToPutCaret);
}

nsresult
HTMLEditor::HandleKeyPressEvent(WidgetKeyboardEvent* aKeyboardEvent)
{
  // NOTE: When you change this method, you should also change:
  //   * editor/libeditor/tests/test_htmleditor_keyevent_handling.html

  if (IsReadonly() || IsDisabled()) {
    // When we're not editable, the events are handled on EditorBase, so, we can
    // bypass TextEditor.
    return EditorBase::HandleKeyPressEvent(aKeyboardEvent);
  }

  if (NS_WARN_IF(!aKeyboardEvent)) {
    return NS_ERROR_UNEXPECTED;
  }
  MOZ_ASSERT(aKeyboardEvent->mMessage == eKeyPress,
             "HandleKeyPressEvent gets non-keypress event");

  switch (aKeyboardEvent->mKeyCode) {
    case NS_VK_META:
    case NS_VK_WIN:
    case NS_VK_SHIFT:
    case NS_VK_CONTROL:
    case NS_VK_ALT:
      // These keys are handled on EditorBase, so, we can bypass
      // TextEditor.
      return EditorBase::HandleKeyPressEvent(aKeyboardEvent);
    case NS_VK_BACK:
    case NS_VK_DELETE:
      // These keys are handled on TextEditor.
      return TextEditor::HandleKeyPressEvent(aKeyboardEvent);
    case NS_VK_TAB: {
      if (IsPlaintextEditor()) {
        // If this works as plain text editor, e.g., mail editor for plain
        // text, should be handled on TextEditor.
        return TextEditor::HandleKeyPressEvent(aKeyboardEvent);
      }

      if (IsTabbable()) {
        return NS_OK; // let it be used for focus switching
      }

      if (aKeyboardEvent->IsControl() || aKeyboardEvent->IsAlt() ||
          aKeyboardEvent->IsMeta() || aKeyboardEvent->IsOS()) {
        return NS_OK;
      }

      RefPtr<Selection> selection = GetSelection();
      NS_ENSURE_TRUE(selection && selection->RangeCount(), NS_ERROR_FAILURE);

      nsCOMPtr<nsINode> node = selection->GetRangeAt(0)->GetStartContainer();
      MOZ_ASSERT(node);

      nsCOMPtr<Element> blockParent = GetBlock(*node);

      if (!blockParent) {
        break;
      }

      bool handled = false;
      nsresult rv = NS_OK;
      if (HTMLEditUtils::IsTableElement(blockParent)) {
        rv = TabInTable(aKeyboardEvent->IsShift(), &handled);
        // TabInTable might cause reframe
        if (Destroyed()) {
          return NS_OK;
        }
        if (handled) {
          ScrollSelectionIntoView(false);
        }
      } else if (HTMLEditUtils::IsListItem(blockParent)) {
        rv = Indent(aKeyboardEvent->IsShift()
                    ? NS_LITERAL_STRING("outdent")
                    : NS_LITERAL_STRING("indent"));
        handled = true;
      }
      NS_ENSURE_SUCCESS(rv, rv);
      if (handled) {
        aKeyboardEvent->PreventDefault(); // consumed
        return NS_OK;
      }
      if (aKeyboardEvent->IsShift()) {
        return NS_OK; // don't type text for shift tabs
      }
      aKeyboardEvent->PreventDefault();
      return OnInputText(NS_LITERAL_STRING("\t"));
    }
    case NS_VK_RETURN:
      if (!aKeyboardEvent->IsInputtingLineBreak()) {
        return NS_OK;
      }
      aKeyboardEvent->PreventDefault(); // consumed
      if (aKeyboardEvent->IsShift()) {
        // Only inserts a <br> element.
        return OnInputLineBreak();
      }
      // uses rules to figure out what to insert
      return OnInputParagraphSeparator();
  }

  if (!aKeyboardEvent->IsInputtingText()) {
    // we don't PreventDefault() here or keybindings like control-x won't work
    return NS_OK;
  }
  aKeyboardEvent->PreventDefault();
  nsAutoString str(aKeyboardEvent->mCharCode);
  return OnInputText(str);
}

/**
 * Returns true if the id represents an element of block type.
 * Can be used to determine if a new paragraph should be started.
 */
bool
HTMLEditor::NodeIsBlockStatic(const nsINode* aElement)
{
  MOZ_ASSERT(aElement);

  // We want to treat these as block nodes even though nsHTMLElement says
  // they're not.
  if (aElement->IsAnyOfHTMLElements(nsGkAtoms::body,
                                    nsGkAtoms::head,
                                    nsGkAtoms::tbody,
                                    nsGkAtoms::thead,
                                    nsGkAtoms::tfoot,
                                    nsGkAtoms::tr,
                                    nsGkAtoms::th,
                                    nsGkAtoms::td,
                                    nsGkAtoms::dt,
                                    nsGkAtoms::dd)) {
    return true;
  }

  return nsHTMLElement::IsBlock(
    nsHTMLTags::AtomTagToId(aElement->NodeInfo()->NameAtom()));
}

NS_IMETHODIMP
HTMLEditor::NodeIsBlock(nsINode* aNode,
                        bool* aIsBlock)
{
  *aIsBlock = IsBlockNode(aNode);
  return NS_OK;
}

bool
HTMLEditor::IsBlockNode(nsINode* aNode)
{
  return aNode && NodeIsBlockStatic(aNode);
}

/**
 * GetBlockNodeParent returns enclosing block level ancestor, if any.
 */
Element*
HTMLEditor::GetBlockNodeParent(nsINode* aNode,
                               nsINode* aAncestorLimiter)
{
  MOZ_ASSERT(aNode);
  MOZ_ASSERT(!aAncestorLimiter ||
             aNode == aAncestorLimiter ||
             EditorUtils::IsDescendantOf(*aNode, *aAncestorLimiter),
             "aNode isn't in aAncestorLimiter");

  // The caller has already reached the limiter.
  if (aNode == aAncestorLimiter) {
    return nullptr;
  }

  nsCOMPtr<nsINode> p = aNode->GetParentNode();

  while (p) {
    if (NodeIsBlockStatic(p)) {
      return p->AsElement();
    }
    // Now, we have reached the limiter, there is no block in its ancestors.
    if (p == aAncestorLimiter) {
      return nullptr;
    }
    p = p->GetParentNode();
  }

  return nullptr;
}

/**
 * Returns the node if it's a block, otherwise GetBlockNodeParent
 */
Element*
HTMLEditor::GetBlock(nsINode& aNode,
                     nsINode* aAncestorLimiter)
{
  MOZ_ASSERT(!aAncestorLimiter ||
             &aNode == aAncestorLimiter ||
             EditorUtils::IsDescendantOf(aNode, *aAncestorLimiter),
             "aNode isn't in aAncestorLimiter");

  if (NodeIsBlockStatic(&aNode)) {
    return aNode.AsElement();
  }
  return GetBlockNodeParent(&aNode, aAncestorLimiter);
}

/**
 * IsNextCharInNodeWhitespace() checks the adjacent content in the same node to
 * see if following selection is whitespace or nbsp.
 */
void
HTMLEditor::IsNextCharInNodeWhitespace(nsIContent* aContent,
                                       int32_t aOffset,
                                       bool* outIsSpace,
                                       bool* outIsNBSP,
                                       nsIContent** outNode,
                                       int32_t* outOffset)
{
  MOZ_ASSERT(aContent && outIsSpace && outIsNBSP);
  MOZ_ASSERT((outNode && outOffset) || (!outNode && !outOffset));
  *outIsSpace = false;
  *outIsNBSP = false;
  if (outNode && outOffset) {
    *outNode = nullptr;
    *outOffset = -1;
  }

  if (aContent->IsText() &&
      (uint32_t)aOffset < aContent->Length()) {
    char16_t ch = aContent->GetText()->CharAt(aOffset);
    *outIsSpace = nsCRT::IsAsciiSpace(ch);
    *outIsNBSP = (ch == kNBSP);
    if (outNode && outOffset) {
      NS_IF_ADDREF(*outNode = aContent);
      // yes, this is _past_ the character
      *outOffset = aOffset + 1;
    }
  }
}


/**
 * IsPrevCharInNodeWhitespace() checks the adjacent content in the same node to
 * see if following selection is whitespace.
 */
void
HTMLEditor::IsPrevCharInNodeWhitespace(nsIContent* aContent,
                                       int32_t aOffset,
                                       bool* outIsSpace,
                                       bool* outIsNBSP,
                                       nsIContent** outNode,
                                       int32_t* outOffset)
{
  MOZ_ASSERT(aContent && outIsSpace && outIsNBSP);
  MOZ_ASSERT((outNode && outOffset) || (!outNode && !outOffset));
  *outIsSpace = false;
  *outIsNBSP = false;
  if (outNode && outOffset) {
    *outNode = nullptr;
    *outOffset = -1;
  }

  if (aContent->IsText() && aOffset > 0) {
    char16_t ch = aContent->GetText()->CharAt(aOffset - 1);
    *outIsSpace = nsCRT::IsAsciiSpace(ch);
    *outIsNBSP = (ch == kNBSP);
    if (outNode && outOffset) {
      NS_IF_ADDREF(*outNode = aContent);
      *outOffset = aOffset - 1;
    }
  }
}

bool
HTMLEditor::IsVisibleBRElement(nsINode* aNode)
{
  MOZ_ASSERT(aNode);
  if (!TextEditUtils::IsBreak(aNode)) {
    return false;
  }
  // Check if there is another element or text node in block after current
  // <br> element.
  // Note that even if following node is non-editable, it may make the
  // <br> element visible if it just exists.
  // E.g., foo<br><button contenteditable="false">button</button>
  // However, we need to ignore invisible data nodes like comment node.
  nsCOMPtr<nsINode> nextNode = GetNextHTMLElementOrTextInBlock(*aNode);
  if (nextNode && TextEditUtils::IsBreak(nextNode)) {
    return true;
  }

  // A single line break before a block boundary is not displayed, so e.g.
  // foo<p>bar<br></p> and foo<br><p>bar</p> display the same as foo<p>bar</p>.
  // But if there are multiple <br>s in a row, all but the last are visible.
  if (!nextNode) {
    // This break is trailer in block, it's not visible
    return false;
  }
  if (IsBlockNode(nextNode)) {
    // Break is right before a block, it's not visible
    return false;
  }

  // If there's an inline node after this one that's not a break, and also a
  // prior break, this break must be visible.
  // Note that even if previous node is non-editable, it may make the
  // <br> element visible if it just exists.
  // E.g., <button contenteditable="false"><br>foo
  // However, we need to ignore invisible data nodes like comment node.
  nsCOMPtr<nsINode> priorNode = GetPreviousHTMLElementOrTextInBlock(*aNode);
  if (priorNode && TextEditUtils::IsBreak(priorNode)) {
    return true;
  }

  // Sigh.  We have to use expensive whitespace calculation code to
  // determine what is going on
  int32_t selOffset;
  nsCOMPtr<nsINode> selNode = GetNodeLocation(aNode, &selOffset);
  // Let's look after the break
  selOffset++;
  WSRunObject wsObj(this, selNode, selOffset);
  nsCOMPtr<nsINode> unused;
  int32_t visOffset = 0;
  WSType visType;
  wsObj.NextVisibleNode(EditorRawDOMPoint(selNode, selOffset),
                        address_of(unused), &visOffset, &visType);
  if (visType & WSType::block) {
    return false;
  }

  return true;
}

NS_IMETHODIMP
HTMLEditor::UpdateBaseURL()
{
  nsCOMPtr<nsIDocument> doc = GetDocument();
  NS_ENSURE_TRUE(doc, NS_ERROR_FAILURE);

  // Look for an HTML <base> tag
  RefPtr<nsContentList> nodeList =
    doc->GetElementsByTagName(NS_LITERAL_STRING("base"));

  // If no base tag, then set baseURL to the document's URL.  This is very
  // important, else relative URLs for links and images are wrong
  if (!nodeList || !nodeList->Item(0)) {
    doc->SetBaseURI(doc->GetDocumentURI());
  }
  return NS_OK;
}

nsresult
HTMLEditor::OnInputLineBreak()
{
  AutoPlaceholderBatch batch(this, nsGkAtoms::TypingTxnName);
  nsresult rv = InsertBrElementAtSelectionWithTransaction();
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }
  return NS_OK;
}

nsresult
HTMLEditor::TabInTable(bool inIsShift,
                       bool* outHandled)
{
  NS_ENSURE_TRUE(outHandled, NS_ERROR_NULL_POINTER);
  *outHandled = false;

  // Find enclosing table cell from selection (cell may be selected element)
  nsCOMPtr<Element> cellElement =
    GetElementOrParentByTagName(NS_LITERAL_STRING("td"), nullptr);
  // Do nothing -- we didn't find a table cell
  NS_ENSURE_TRUE(cellElement, NS_OK);

  // find enclosing table
  nsCOMPtr<Element> table = GetEnclosingTable(cellElement);
  NS_ENSURE_TRUE(table, NS_OK);

  // advance to next cell
  // first create an iterator over the table
  nsCOMPtr<nsIContentIterator> iter = NS_NewContentIterator();
  nsresult rv = iter->Init(table);
  NS_ENSURE_SUCCESS(rv, rv);
  // position iter at block
  rv = iter->PositionAt(cellElement);
  NS_ENSURE_SUCCESS(rv, rv);

  nsCOMPtr<nsINode> node;
  do {
    if (inIsShift) {
      iter->Prev();
    } else {
      iter->Next();
    }

    node = iter->GetCurrentNode();

    if (node && HTMLEditUtils::IsTableCell(node) &&
        GetEnclosingTable(node) == table) {
      CollapseSelectionToDeepestNonTableFirstChild(nullptr, node);
      *outHandled = true;
      return NS_OK;
    }
  } while (!iter->IsDone());

  if (!(*outHandled) && !inIsShift) {
    // If we haven't handled it yet, then we must have run off the end of the
    // table.  Insert a new row.
    rv = InsertTableRow(1, true);
    NS_ENSURE_SUCCESS(rv, rv);
    *outHandled = true;
    // Put selection in right place.  Use table code to get selection and index
    // to new row...
    RefPtr<Selection> selection;
    RefPtr<Element> tblElement, cell;
    int32_t row;
    rv = GetCellContext(getter_AddRefs(selection),
                        getter_AddRefs(tblElement),
                        getter_AddRefs(cell),
                        nullptr, nullptr,
                        &row, nullptr);
    NS_ENSURE_SUCCESS(rv, rv);
    // ...so that we can ask for first cell in that row...
    rv = GetCellAt(tblElement, row, 0, getter_AddRefs(cell));
    NS_ENSURE_SUCCESS(rv, rv);
    // ...and then set selection there.  (Note that normally you should use
    // CollapseSelectionToDeepestNonTableFirstChild(), but we know cell is an
    // empty new cell, so this works fine)
    if (cell) {
      selection->Collapse(cell, 0);
    }
  }

  return NS_OK;
}

nsresult
HTMLEditor::InsertBrElementAtSelectionWithTransaction()
{
  // calling it text insertion to trigger moz br treatment by rules
  // XXX Why do we use EditSubAction::eInsertText here?  Looks like
  //     EditSubAction::eInsertParagraphSeparator or EditSubAction::eInsertNode
  //     is better.
  AutoTopLevelEditSubActionNotifier maybeTopLevelEditSubAction(
                                      *this, EditSubAction::eInsertText,
                                      nsIEditor::eNext);

  RefPtr<Selection> selection = GetSelection();
  NS_ENSURE_STATE(selection);

  if (!selection->IsCollapsed()) {
    nsresult rv = DeleteSelectionAsSubAction(eNone, eStrip);
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }
  }

  EditorRawDOMPoint atStartOfSelection(GetStartPoint(selection));
  if (NS_WARN_IF(!atStartOfSelection.IsSet())) {
    return NS_ERROR_FAILURE;
  }

  // InsertBrElementWithTransaction() will set selection after the new <br>
  // element.
  RefPtr<Element> newBrElement =
    InsertBrElementWithTransaction(*selection, atStartOfSelection, eNext);
  if (NS_WARN_IF(!newBrElement)) {
    return NS_ERROR_FAILURE;
  }
  return NS_OK;
}

void
HTMLEditor::CollapseSelectionToDeepestNonTableFirstChild(Selection* aSelection,
                                                         nsINode* aNode)
{
  MOZ_ASSERT(aNode);

  RefPtr<Selection> selection = aSelection;
  if (!selection) {
    selection = GetSelection();
  }
  if (!selection) {
    // Nothing to do
    return;
  }

  nsCOMPtr<nsINode> node = aNode;

  for (nsCOMPtr<nsIContent> child = node->GetFirstChild();
       child;
       child = child->GetFirstChild()) {
    // Stop if we find a table, don't want to go into nested tables
    if (HTMLEditUtils::IsTable(child) || !IsContainer(child)) {
      break;
    }
    node = child;
  }

  selection->Collapse(node, 0);
}

nsresult
HTMLEditor::ReplaceHeadContentsWithSourceWithTransaction(
              const nsAString& aSourceToInsert)
{
  // don't do any post processing, rules get confused
  AutoTopLevelEditSubActionNotifier
    maybeTopLevelEditSubAction(*this,
                               EditSubAction::eReplaceHeadWithHTMLSource,
                               nsIEditor::eNone);
  RefPtr<Selection> selection = GetSelection();
  NS_ENSURE_TRUE(selection, NS_ERROR_NULL_POINTER);

  CommitComposition();

  // Do not use AutoTopLevelEditSubActionNotifier -- rules code won't let us
  // insert in <head>.  Use the head node as a parent and delete/insert
  // directly.
  // XXX We're using AutoTopLevelEditSubActionNotifier above...
  nsCOMPtr<nsIDocument> document = GetDocument();
  if (NS_WARN_IF(!document)) {
    return NS_ERROR_NOT_INITIALIZED;
  }

  RefPtr<nsContentList> nodeList =
    document->GetElementsByTagName(NS_LITERAL_STRING("head"));
  if (NS_WARN_IF(!nodeList)) {
    return NS_ERROR_FAILURE;
  }

  nsCOMPtr<nsIContent> headNode = nodeList->Item(0);
  if (NS_WARN_IF(!headNode)) {
    return NS_ERROR_FAILURE;
  }

  // First, make sure there are no return chars in the source.  Bad things
  // happen if you insert returns (instead of dom newlines, \n) into an editor
  // document.
  nsAutoString inputString(aSourceToInsert);

  // Windows linebreaks: Map CRLF to LF:
  inputString.ReplaceSubstring(NS_LITERAL_STRING("\r\n"),
                               NS_LITERAL_STRING("\n"));

  // Mac linebreaks: Map any remaining CR to LF:
  inputString.ReplaceSubstring(NS_LITERAL_STRING("\r"),
                               NS_LITERAL_STRING("\n"));

  AutoPlaceholderBatch beginBatching(this);

  // Get the first range in the selection, for context:
  RefPtr<nsRange> range = selection->GetRangeAt(0);
  if (NS_WARN_IF(!range)) {
    return NS_ERROR_FAILURE;
  }

  ErrorResult err;
  RefPtr<DocumentFragment> documentFragment =
    range->CreateContextualFragment(inputString, err);

  // XXXX BUG 50965: This is not returning the text between <title>...</title>
  // Special code is needed in JS to handle title anyway, so it doesn't matter!

  if (err.Failed()) {
    return err.StealNSResult();
  }
  if (NS_WARN_IF(!documentFragment)) {
    return NS_ERROR_FAILURE;
  }

  // First delete all children in head
  while (nsCOMPtr<nsIContent> child = headNode->GetFirstChild()) {
    nsresult rv = DeleteNodeWithTransaction(*child);
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }
  }

  // Now insert the new nodes
  int32_t offsetOfNewNode = 0;

  // Loop over the contents of the fragment and move into the document
  while (nsCOMPtr<nsIContent> child = documentFragment->GetFirstChild()) {
    nsresult rv =
      InsertNodeWithTransaction(*child,
                                EditorRawDOMPoint(headNode, offsetOfNewNode++));
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }
  }

  return NS_OK;
}

NS_IMETHODIMP
HTMLEditor::RebuildDocumentFromSource(const nsAString& aSourceString)
{
  CommitComposition();

  RefPtr<Selection> selection = GetSelection();
  NS_ENSURE_TRUE(selection, NS_ERROR_NULL_POINTER);

  RefPtr<Element> rootElement = GetRoot();
  if (NS_WARN_IF(!rootElement)) {
    return NS_ERROR_NULL_POINTER;
  }

  // Find where the <body> tag starts.
  nsReadingIterator<char16_t> beginbody;
  nsReadingIterator<char16_t> endbody;
  aSourceString.BeginReading(beginbody);
  aSourceString.EndReading(endbody);
  bool foundbody = CaseInsensitiveFindInReadable(NS_LITERAL_STRING("<body"),
                                                 beginbody, endbody);

  nsReadingIterator<char16_t> beginhead;
  nsReadingIterator<char16_t> endhead;
  aSourceString.BeginReading(beginhead);
  aSourceString.EndReading(endhead);
  bool foundhead = CaseInsensitiveFindInReadable(NS_LITERAL_STRING("<head"),
                                                 beginhead, endhead);
  // a valid head appears before the body
  if (foundbody && beginhead.get() > beginbody.get()) {
    foundhead = false;
  }

  nsReadingIterator<char16_t> beginclosehead;
  nsReadingIterator<char16_t> endclosehead;
  aSourceString.BeginReading(beginclosehead);
  aSourceString.EndReading(endclosehead);

  // Find the index after "<head>"
  bool foundclosehead = CaseInsensitiveFindInReadable(
           NS_LITERAL_STRING("</head>"), beginclosehead, endclosehead);
  // a valid close head appears after a found head
  if (foundhead && beginhead.get() > beginclosehead.get()) {
    foundclosehead = false;
  }
  // a valid close head appears before a found body
  if (foundbody && beginclosehead.get() > beginbody.get()) {
    foundclosehead = false;
  }

  // Time to change the document
  AutoPlaceholderBatch beginBatching(this);

  nsReadingIterator<char16_t> endtotal;
  aSourceString.EndReading(endtotal);

  if (foundhead) {
    if (foundclosehead) {
      nsresult rv =
        ReplaceHeadContentsWithSourceWithTransaction(
          Substring(beginhead, beginclosehead));
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }
    } else if (foundbody) {
      nsresult rv =
        ReplaceHeadContentsWithSourceWithTransaction(
          Substring(beginhead, beginbody));
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }
    } else {
      // XXX Without recourse to some parser/content sink/docshell hackery we
      // don't really know where the head ends and the body begins so we assume
      // that there is no body
      nsresult rv =
        ReplaceHeadContentsWithSourceWithTransaction(
          Substring(beginhead, endtotal));
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }
    }
  } else {
    nsReadingIterator<char16_t> begintotal;
    aSourceString.BeginReading(begintotal);
    NS_NAMED_LITERAL_STRING(head, "<head>");
    if (foundclosehead) {
      nsresult rv =
        ReplaceHeadContentsWithSourceWithTransaction(
          head + Substring(begintotal, beginclosehead));
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }
    } else if (foundbody) {
      nsresult rv =
        ReplaceHeadContentsWithSourceWithTransaction(
          head + Substring(begintotal, beginbody));
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }
    } else {
      // XXX Without recourse to some parser/content sink/docshell hackery we
      // don't really know where the head ends and the body begins so we assume
      // that there is no head
      nsresult rv = ReplaceHeadContentsWithSourceWithTransaction(head);
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }
    }
  }

  nsresult rv = SelectAll();
  NS_ENSURE_SUCCESS(rv, rv);

  if (!foundbody) {
    NS_NAMED_LITERAL_STRING(body, "<body>");
    // XXX Without recourse to some parser/content sink/docshell hackery we
    // don't really know where the head ends and the body begins
    if (foundclosehead) {
      // assume body starts after the head ends
      nsresult rv = LoadHTML(body + Substring(endclosehead, endtotal));
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }
    } else if (foundhead) {
      // assume there is no body
      nsresult rv = LoadHTML(body);
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }
    } else {
      // assume there is no head, the entire source is body
      nsresult rv = LoadHTML(body + aSourceString);
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }
    }

    RefPtr<Element> divElement =
      CreateElementWithDefaults(NS_LITERAL_STRING("div"));
    if (NS_WARN_IF(!divElement)) {
      return NS_ERROR_FAILURE;
    }
    CloneAttributesWithTransaction(*rootElement, *divElement);

    return MaybeCollapseSelectionAtFirstEditableNode(false);
  }

  rv = LoadHTML(Substring(beginbody, endtotal));
  NS_ENSURE_SUCCESS(rv, rv);

  // Now we must copy attributes user might have edited on the <body> tag
  // because InsertHTML (actually, CreateContextualFragment()) will never
  // return a body node in the DOM fragment

  // We already know where "<body" begins
  nsReadingIterator<char16_t> beginclosebody = beginbody;
  nsReadingIterator<char16_t> endclosebody;
  aSourceString.EndReading(endclosebody);
  if (!FindInReadable(NS_LITERAL_STRING(">"), beginclosebody, endclosebody)) {
    return NS_ERROR_FAILURE;
  }

  // Truncate at the end of the body tag.  Kludge of the year: fool the parser
  // by replacing "body" with "div" so we get a node
  nsAutoString bodyTag;
  bodyTag.AssignLiteral("<div ");
  bodyTag.Append(Substring(endbody, endclosebody));

  RefPtr<nsRange> range = selection->GetRangeAt(0);
  NS_ENSURE_TRUE(range, NS_ERROR_FAILURE);

  ErrorResult erv;
  RefPtr<DocumentFragment> docfrag =
    range->CreateContextualFragment(bodyTag, erv);
  NS_ENSURE_TRUE(!erv.Failed(), erv.StealNSResult());
  NS_ENSURE_TRUE(docfrag, NS_ERROR_NULL_POINTER);

  nsCOMPtr<nsIContent> child = docfrag->GetFirstChild();
  NS_ENSURE_TRUE(child && child->IsElement(), NS_ERROR_NULL_POINTER);

  // Copy all attributes from the div child to current body element
  CloneAttributesWithTransaction(*rootElement, *child->AsElement());

  // place selection at first editable content
  return MaybeCollapseSelectionAtFirstEditableNode(false);
}

EditorRawDOMPoint
HTMLEditor::GetBetterInsertionPointFor(nsINode& aNodeToInsert,
                                       const EditorRawDOMPoint& aPointToInsert)
{
  if (NS_WARN_IF(!aPointToInsert.IsSet())) {
    return aPointToInsert;
  }

  EditorRawDOMPoint pointToInsert(aPointToInsert.GetNonAnonymousSubtreePoint());
  if (NS_WARN_IF(!pointToInsert.IsSet())) {
    // Cannot insert aNodeToInsert into this DOM tree.
    return EditorRawDOMPoint();
  }

  // If the node to insert is not a block level element, we can insert it
  // at any point.
  if (!IsBlockNode(&aNodeToInsert)) {
    return pointToInsert;
  }

  WSRunObject wsObj(this, pointToInsert.GetContainer(),
                    pointToInsert.Offset());

  // If the insertion position is after the last visible item in a line,
  // i.e., the insertion position is just before a visible line break <br>,
  // we want to skip to the position just after the line break (see bug 68767).
  nsCOMPtr<nsINode> nextVisibleNode;
  int32_t nextVisibleOffset = 0;
  WSType nextVisibleType;
  wsObj.NextVisibleNode(pointToInsert, address_of(nextVisibleNode),
                        &nextVisibleOffset, &nextVisibleType);
  // So, if the next visible node isn't a <br> element, we can insert the block
  // level element to the point.
  if (!nextVisibleNode ||
      !(nextVisibleType & WSType::br)) {
    return pointToInsert;
  }

  // However, we must not skip next <br> element when the caret appears to be
  // positioned at the beginning of a block, in that case skipping the <br>
  // would not insert the <br> at the caret position, but after the current
  // empty line.
  nsCOMPtr<nsINode> previousVisibleNode;
  int32_t previousVisibleOffset = 0;
  WSType previousVisibleType;
  wsObj.PriorVisibleNode(pointToInsert, address_of(previousVisibleNode),
                         &previousVisibleOffset, &previousVisibleType);
  // So, if there is no previous visible node,
  // or, if both nodes of the insertion point is <br> elements,
  // or, if the previous visible node is different block,
  // we need to skip the following <br>.  So, otherwise, we can insert the
  // block at the insertion point.
  if (!previousVisibleNode ||
      (previousVisibleType & WSType::br) ||
      (previousVisibleType & WSType::thisBlock)) {
    return pointToInsert;
  }

  EditorRawDOMPoint afterBRNode(nextVisibleNode);
  DebugOnly<bool> advanced = afterBRNode.AdvanceOffset();
  NS_WARNING_ASSERTION(advanced,
    "Failed to advance offset to after the <br> node");
  return afterBRNode;
}

NS_IMETHODIMP
HTMLEditor::InsertElementAtSelection(Element* aElement,
                                     bool aDeleteSelection)
{
  // Protect the edit rules object from dying
  RefPtr<TextEditRules> rules(mRules);

  NS_ENSURE_TRUE(aElement, NS_ERROR_NULL_POINTER);

  CommitComposition();
  AutoPlaceholderBatch beginBatching(this);
  AutoTopLevelEditSubActionNotifier maybeTopLevelEditSubAction(
                                      *this, EditSubAction::eInsertElement,
                                      nsIEditor::eNext);

  RefPtr<Selection> selection = GetSelection();
  if (!selection) {
    return NS_ERROR_FAILURE;
  }

  // hand off to the rules system, see if it has anything to say about this
  bool cancel, handled;
  EditSubActionInfo subActionInfo(EditSubAction::eInsertElement);
  nsresult rv =
    rules->WillDoAction(selection, subActionInfo, &cancel, &handled);
  if (cancel || NS_FAILED(rv)) {
    return rv;
  }

  if (!handled) {
    if (aDeleteSelection) {
      if (!IsBlockNode(aElement)) {
        // E.g., inserting an image.  In this case we don't need to delete any
        // inline wrappers before we do the insertion.  Otherwise we let
        // DeleteSelectionAndPrepareToCreateNode do the deletion for us, which
        // calls DeleteSelection with aStripWrappers = eStrip.
        rv = DeleteSelectionAsSubAction(eNone, eNoStrip);
        if (NS_WARN_IF(NS_FAILED(rv))) {
          return rv;
        }
      }

      nsresult rv = DeleteSelectionAndPrepareToCreateNode();
      NS_ENSURE_SUCCESS(rv, rv);
    }

    // If deleting, selection will be collapsed.
    // so if not, we collapse it
    if (!aDeleteSelection) {
      // Named Anchor is a special case,
      // We collapse to insert element BEFORE the selection
      // For all other tags, we insert AFTER the selection
      if (HTMLEditUtils::IsNamedAnchor(aElement)) {
        selection->CollapseToStart(IgnoreErrors());
      } else {
        selection->CollapseToEnd(IgnoreErrors());
      }
    }

    if (selection->GetAnchorNode()) {
      EditorRawDOMPoint atAnchor(selection->AnchorRef());
      // Adjust position based on the node we are going to insert.
      EditorRawDOMPoint pointToInsert =
        GetBetterInsertionPointFor(*aElement, atAnchor);
      if (NS_WARN_IF(!pointToInsert.IsSet())) {
        return NS_ERROR_FAILURE;
      }

      EditorDOMPoint insertedPoint =
        InsertNodeIntoProperAncestorWithTransaction(
          *aElement, pointToInsert, SplitAtEdges::eAllowToCreateEmptyContainer);
      if (NS_WARN_IF(!insertedPoint.IsSet())) {
        return NS_ERROR_FAILURE;
      }
      // Set caret after element, but check for special case
      //  of inserting table-related elements: set in first cell instead
      if (!SetCaretInTableCell(aElement)) {
        rv = SetCaretAfterElement(aElement);
        NS_ENSURE_SUCCESS(rv, rv);
      }
      // check for inserting a whole table at the end of a block. If so insert
      // a br after it.
      if (HTMLEditUtils::IsTable(aElement) &&
          IsLastEditableChild(aElement)) {
        DebugOnly<bool> advanced = insertedPoint.AdvanceOffset();
        NS_WARNING_ASSERTION(advanced,
          "Failed to advance offset from inserted point");
        // Collapse selection to the new <br> element node after creating it.
        RefPtr<Element> newBrElement =
          InsertBrElementWithTransaction(*selection, insertedPoint, ePrevious);
        if (NS_WARN_IF(!newBrElement)) {
          return NS_ERROR_FAILURE;
        }
      }
    }
  }
  rv = rules->DidDoAction(selection, subActionInfo, rv);
  return rv;
}

template<typename PT, typename CT>
EditorDOMPoint
HTMLEditor::InsertNodeIntoProperAncestorWithTransaction(
              nsIContent& aNode,
              const EditorDOMPointBase<PT, CT>& aPointToInsert,
              SplitAtEdges aSplitAtEdges)
{
  if (NS_WARN_IF(!aPointToInsert.IsSet())) {
    return EditorDOMPoint();
  }
  MOZ_ASSERT(aPointToInsert.IsSetAndValid());

  // Search up the parent chain to find a suitable container.
  EditorDOMPoint pointToInsert(aPointToInsert);
  MOZ_ASSERT(pointToInsert.IsSet());
  while (!CanContain(*pointToInsert.GetContainer(), aNode)) {
    // If the current parent is a root (body or table element)
    // then go no further - we can't insert.
    if (pointToInsert.IsContainerHTMLElement(nsGkAtoms::body) ||
        HTMLEditUtils::IsTableElement(pointToInsert.GetContainer())) {
      return EditorDOMPoint();
    }

    // Get the next point.
    pointToInsert.Set(pointToInsert.GetContainer());
    if (NS_WARN_IF(!pointToInsert.IsSet())) {
      return EditorDOMPoint();
    }

    if (!IsEditable(pointToInsert.GetContainer())) {
      // There's no suitable place to put the node in this editing host.  Maybe
      // someone is trying to put block content in a span.  So just put it
      // where we were originally asked.
      pointToInsert = aPointToInsert;
      break;
    }
  }

  if (pointToInsert != aPointToInsert) {
    // We need to split some levels above the original selection parent.
    MOZ_ASSERT(pointToInsert.GetChild());
    SplitNodeResult splitNodeResult =
      SplitNodeDeepWithTransaction(*pointToInsert.GetChild(),
                                   aPointToInsert, aSplitAtEdges);
    if (NS_WARN_IF(splitNodeResult.Failed())) {
      return EditorDOMPoint();
    }
    pointToInsert = splitNodeResult.SplitPoint();
    MOZ_ASSERT(pointToInsert.IsSet());
  }

  {
    // After inserting a node, pointToInsert will refer next sibling of
    // the new node but keep referring the new node's offset.
    // This method's result should be the point at insertion, it's useful
    // even if the new node is moved by mutation observer immediately.
    // So, let's lock only the offset and child node should be recomputed
    // when it's necessary.
    AutoEditorDOMPointChildInvalidator lockOffset(pointToInsert);
    // Now we can insert the new node.
    nsresult rv = InsertNodeWithTransaction(aNode, pointToInsert);
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return EditorDOMPoint();
    }
  }
  return pointToInsert;
}

NS_IMETHODIMP
HTMLEditor::SelectElement(Element* aElement)
{
  // Must be sure that element is contained in the document body
  if (!IsDescendantOfEditorRoot(aElement)) {
    return NS_ERROR_NULL_POINTER;
  }

  RefPtr<Selection> selection = GetSelection();
  NS_ENSURE_TRUE(selection, NS_ERROR_NULL_POINTER);
  nsINode* parent = aElement->GetParentNode();
  if (NS_WARN_IF(!parent)) {
    return NS_ERROR_FAILURE;
  }

  int32_t offsetInParent = parent->ComputeIndexOf(aElement);

  // Collapse selection to just before desired element,
  nsresult rv = selection->Collapse(parent, offsetInParent);
  if (NS_SUCCEEDED(rv)) {
    // then extend it to just after
    rv = selection->Extend(parent, offsetInParent + 1);
  }
  return rv;
}

NS_IMETHODIMP
HTMLEditor::SetCaretAfterElement(Element* aElement)
{
  // Be sure the element is contained in the document body
  if (!aElement || !IsDescendantOfEditorRoot(aElement)) {
    return NS_ERROR_NULL_POINTER;
  }

  RefPtr<Selection> selection = GetSelection();
  NS_ENSURE_TRUE(selection, NS_ERROR_NULL_POINTER);
  nsCOMPtr<nsINode> parent = aElement->GetParentNode();
  NS_ENSURE_TRUE(parent, NS_ERROR_NULL_POINTER);
  // Collapse selection to just after desired element,
  EditorRawDOMPoint afterElement(aElement);
  if (NS_WARN_IF(!afterElement.AdvanceOffset())) {
    return NS_ERROR_FAILURE;
  }
  return selection->Collapse(afterElement);
}

NS_IMETHODIMP
HTMLEditor::SetParagraphFormat(const nsAString& aParagraphFormat)
{
  nsAutoString lowerCaseTagName(aParagraphFormat);
  ToLowerCase(lowerCaseTagName);
  RefPtr<nsAtom> tagName = NS_Atomize(lowerCaseTagName);
  MOZ_ASSERT(tagName);
  if (tagName == nsGkAtoms::dd || tagName == nsGkAtoms::dt) {
    return MakeDefinitionListItemWithTransaction(*tagName);
  }
  return InsertBasicBlockWithTransaction(*tagName);
}

NS_IMETHODIMP
HTMLEditor::GetParagraphState(bool* aMixed,
                              nsAString& outFormat)
{
  if (!mRules) {
    return NS_ERROR_NOT_INITIALIZED;
  }
  NS_ENSURE_TRUE(aMixed, NS_ERROR_NULL_POINTER);
  RefPtr<HTMLEditRules> htmlRules(mRules->AsHTMLEditRules());
  return htmlRules->GetParagraphState(aMixed, outFormat);
}

NS_IMETHODIMP
HTMLEditor::GetBackgroundColorState(bool* aMixed,
                                    nsAString& aOutColor)
{
  if (IsCSSEnabled()) {
    // if we are in CSS mode, we have to check if the containing block defines
    // a background color
    return GetCSSBackgroundColorState(aMixed, aOutColor, true);
  }
  // in HTML mode, we look only at page's background
  return GetHTMLBackgroundColorState(aMixed, aOutColor);
}

NS_IMETHODIMP
HTMLEditor::GetHighlightColorState(bool* aMixed,
                                   nsAString& aOutColor)
{
  *aMixed = false;
  aOutColor.AssignLiteral("transparent");
  if (!IsCSSEnabled()) {
    return NS_OK;
  }

  // in CSS mode, text background can be added by the Text Highlight button
  // we need to query the background of the selection without looking for
  // the block container of the ranges in the selection
  return GetCSSBackgroundColorState(aMixed, aOutColor, false);
}

nsresult
HTMLEditor::GetCSSBackgroundColorState(bool* aMixed,
                                       nsAString& aOutColor,
                                       bool aBlockLevel)
{
  NS_ENSURE_TRUE(aMixed, NS_ERROR_NULL_POINTER);
  *aMixed = false;
  // the default background color is transparent
  aOutColor.AssignLiteral("transparent");

  // get selection
  RefPtr<Selection> selection = GetSelection();
  NS_ENSURE_STATE(selection && selection->GetRangeAt(0));

  // get selection location
  nsCOMPtr<nsINode> parent = selection->GetRangeAt(0)->GetStartContainer();
  NS_ENSURE_TRUE(parent, NS_ERROR_NULL_POINTER);

  // is the selection collapsed?
  nsCOMPtr<nsINode> nodeToExamine;
  if (selection->IsCollapsed() || IsTextNode(parent)) {
    // we want to look at the parent and ancestors
    nodeToExamine = parent;
  } else {
    // otherwise we want to look at the first editable node after
    // {parent,offset} and its ancestors for divs with alignment on them
    nodeToExamine = selection->GetRangeAt(0)->GetChildAtStartOffset();
    //GetNextNode(parent, offset, true, address_of(nodeToExamine));
  }

  NS_ENSURE_TRUE(nodeToExamine, NS_ERROR_NULL_POINTER);

  if (aBlockLevel) {
    // we are querying the block background (and not the text background), let's
    // climb to the block container
    nsCOMPtr<Element> blockParent = GetBlock(*nodeToExamine);
    NS_ENSURE_TRUE(blockParent, NS_OK);

    // Make sure to not walk off onto the Document node
    do {
      // retrieve the computed style of background-color for blockParent
      CSSEditUtils::GetComputedProperty(*blockParent,
                                        *nsGkAtoms::backgroundColor,
                                        aOutColor);
      blockParent = blockParent->GetParentElement();
      // look at parent if the queried color is transparent and if the node to
      // examine is not the root of the document
    } while (aOutColor.EqualsLiteral("transparent") && blockParent);
    if (aOutColor.EqualsLiteral("transparent")) {
      // we have hit the root of the document and the color is still transparent !
      // Grumble... Let's look at the default background color because that's the
      // color we are looking for
      CSSEditUtils::GetDefaultBackgroundColor(aOutColor);
    }
  }
  else {
    // no, we are querying the text background for the Text Highlight button
    if (IsTextNode(nodeToExamine)) {
      // if the node of interest is a text node, let's climb a level
      nodeToExamine = nodeToExamine->GetParentNode();
    }
    // Return default value due to no parent node
    if (!nodeToExamine) {
      return NS_OK;
    }
    do {
      // is the node to examine a block ?
      if (NodeIsBlockStatic(nodeToExamine)) {
        // yes it is a block; in that case, the text background color is transparent
        aOutColor.AssignLiteral("transparent");
        break;
      } else {
        // no, it's not; let's retrieve the computed style of background-color for the
        // node to examine
        CSSEditUtils::GetComputedProperty(*nodeToExamine,
                                          *nsGkAtoms::backgroundColor,
                                          aOutColor);
        if (!aOutColor.EqualsLiteral("transparent")) {
          break;
        }
      }
      nodeToExamine = nodeToExamine->GetParentNode();
    } while ( aOutColor.EqualsLiteral("transparent") && nodeToExamine );
  }
  return NS_OK;
}

nsresult
HTMLEditor::GetHTMLBackgroundColorState(bool* aMixed,
                                        nsAString& aOutColor)
{
  //TODO: We don't handle "mixed" correctly!
  NS_ENSURE_TRUE(aMixed, NS_ERROR_NULL_POINTER);
  *aMixed = false;
  aOutColor.Truncate();

  RefPtr<Element> element;
  int32_t selectedCount;
  nsAutoString tagName;
  nsresult rv = GetSelectedOrParentTableElement(tagName,
                                                &selectedCount,
                                                getter_AddRefs(element));
  NS_ENSURE_SUCCESS(rv, rv);

  while (element) {
    // We are in a cell or selected table
    element->GetAttr(kNameSpaceID_None, nsGkAtoms::bgcolor, aOutColor);

    // Done if we have a color explicitly set
    if (!aOutColor.IsEmpty()) {
      return NS_OK;
    }

    // Once we hit the body, we're done
    if (element->IsHTMLElement(nsGkAtoms::body)) {
      return NS_OK;
    }

    // No color is set, but we need to report visible color inherited
    // from nested cells/tables, so search up parent chain
    element = element->GetParentElement();
  }

  // If no table or cell found, get page body
  dom::Element* bodyElement = GetRoot();
  NS_ENSURE_TRUE(bodyElement, NS_ERROR_NULL_POINTER);

  bodyElement->GetAttr(kNameSpaceID_None, nsGkAtoms::bgcolor, aOutColor);
  return NS_OK;
}

NS_IMETHODIMP
HTMLEditor::GetListState(bool* aMixed,
                         bool* aOL,
                         bool* aUL,
                         bool* aDL)
{
  if (!mRules) {
    return NS_ERROR_NOT_INITIALIZED;
  }
  NS_ENSURE_TRUE(aMixed && aOL && aUL && aDL, NS_ERROR_NULL_POINTER);
  RefPtr<HTMLEditRules> htmlRules(mRules->AsHTMLEditRules());
  return htmlRules->GetListState(aMixed, aOL, aUL, aDL);
}

NS_IMETHODIMP
HTMLEditor::GetListItemState(bool* aMixed,
                             bool* aLI,
                             bool* aDT,
                             bool* aDD)
{
  if (!mRules) {
    return NS_ERROR_NOT_INITIALIZED;
  }
  NS_ENSURE_TRUE(aMixed && aLI && aDT && aDD, NS_ERROR_NULL_POINTER);

  RefPtr<HTMLEditRules> htmlRules(mRules->AsHTMLEditRules());
  return htmlRules->GetListItemState(aMixed, aLI, aDT, aDD);
}

NS_IMETHODIMP
HTMLEditor::GetAlignment(bool* aMixed,
                         nsIHTMLEditor::EAlignment* aAlign)
{
  if (!mRules) {
    return NS_ERROR_NOT_INITIALIZED;
  }
  NS_ENSURE_TRUE(aMixed && aAlign, NS_ERROR_NULL_POINTER);

  RefPtr<HTMLEditRules> htmlRules(mRules->AsHTMLEditRules());
  return htmlRules->GetAlignment(aMixed, aAlign);
}

NS_IMETHODIMP
HTMLEditor::MakeOrChangeList(const nsAString& aListType,
                             bool entireList,
                             const nsAString& aBulletType)
{
  if (!mRules) {
    return NS_ERROR_NOT_INITIALIZED;
  }

  // Protect the edit rules object from dying
  RefPtr<TextEditRules> rules(mRules);

  bool cancel, handled;

  AutoPlaceholderBatch beginBatching(this);
  AutoTopLevelEditSubActionNotifier maybeTopLevelEditSubAction(
                                      *this, EditSubAction::eCreateOrChangeList,
                                      nsIEditor::eNext);

  // pre-process
  RefPtr<Selection> selection = GetSelection();
  NS_ENSURE_TRUE(selection, NS_ERROR_NULL_POINTER);

  EditSubActionInfo subActionInfo(EditSubAction::eCreateOrChangeList);
  subActionInfo.blockType = &aListType;
  subActionInfo.entireList = entireList;
  subActionInfo.bulletType = &aBulletType;
  nsresult rv =
    rules->WillDoAction(selection, subActionInfo, &cancel, &handled);
  if (cancel || NS_FAILED(rv)) {
    return rv;
  }

  if (!handled && selection->IsCollapsed()) {
    nsRange* firstRange = selection->GetRangeAt(0);
    if (NS_WARN_IF(!firstRange)) {
      return NS_ERROR_FAILURE;
    }

    EditorRawDOMPoint atStartOfSelection(firstRange->StartRef());
    if (NS_WARN_IF(!atStartOfSelection.IsSet()) ||
        NS_WARN_IF(!atStartOfSelection.GetContainerAsContent())) {
      return NS_ERROR_FAILURE;
    }

    // Have to find a place to put the list.
    EditorDOMPoint pointToInsertList(atStartOfSelection);

    RefPtr<nsAtom> listAtom = NS_Atomize(aListType);
    while (!CanContainTag(*pointToInsertList.GetContainer(), *listAtom)) {
      pointToInsertList.Set(pointToInsertList.GetContainer());
      if (NS_WARN_IF(!pointToInsertList.IsSet()) ||
          NS_WARN_IF(!pointToInsertList.GetContainerAsContent())) {
        return NS_ERROR_FAILURE;
      }
    }

    if (pointToInsertList.GetContainer() != atStartOfSelection.GetContainer()) {
      // We need to split up to the child of parent.
      SplitNodeResult splitNodeResult =
        SplitNodeDeepWithTransaction(
          *pointToInsertList.GetChild(), atStartOfSelection,
          SplitAtEdges::eAllowToCreateEmptyContainer);
      if (NS_WARN_IF(splitNodeResult.Failed())) {
        return splitNodeResult.Rv();
      }
      pointToInsertList = splitNodeResult.SplitPoint();
      if (NS_WARN_IF(!pointToInsertList.IsSet())) {
        return NS_ERROR_FAILURE;
      }
    }

    // Create a list and insert it before the right node if we split some
    // parents of start of selection above, or just start of selection
    // otherwise.
    RefPtr<Element> newList =
      CreateNodeWithTransaction(*listAtom, pointToInsertList);
    if (NS_WARN_IF(!newList)) {
      return NS_ERROR_FAILURE;
    }
    // make a list item
    EditorRawDOMPoint atStartOfNewList(newList, 0);
    RefPtr<Element> newItem =
      CreateNodeWithTransaction(*nsGkAtoms::li, atStartOfNewList);
    if (NS_WARN_IF(!newItem)) {
      return NS_ERROR_FAILURE;
    }
    ErrorResult error;
    selection->Collapse(RawRangeBoundary(newItem, 0), error);
    if (NS_WARN_IF(error.Failed())) {
      return error.StealNSResult();
    }
  }

  return rules->DidDoAction(selection, subActionInfo, rv);
}

NS_IMETHODIMP
HTMLEditor::RemoveList(const nsAString& aListType)
{
  if (!mRules) {
    return NS_ERROR_NOT_INITIALIZED;
  }

  // Protect the edit rules object from dying
  RefPtr<TextEditRules> rules(mRules);

  bool cancel, handled;

  AutoPlaceholderBatch beginBatching(this);
  AutoTopLevelEditSubActionNotifier maybeTopLevelEditSubAction(
                                      *this, EditSubAction::eRemoveList,
                                      nsIEditor::eNext);

  // pre-process
  RefPtr<Selection> selection = GetSelection();
  NS_ENSURE_TRUE(selection, NS_ERROR_NULL_POINTER);

  EditSubActionInfo subActionInfo(EditSubAction::eRemoveList);
  if (aListType.LowerCaseEqualsLiteral("ol")) {
    subActionInfo.bOrdered = true;
  } else {
    subActionInfo.bOrdered = false;
  }
  nsresult rv =
    rules->WillDoAction(selection, subActionInfo, &cancel, &handled);
  if (cancel || NS_FAILED(rv)) {
    return rv;
  }

  // no default behavior for this yet.  what would it mean?

  return rules->DidDoAction(selection, subActionInfo, rv);
}

nsresult
HTMLEditor::MakeDefinitionListItemWithTransaction(nsAtom& aTagName)
{
  if (!mRules) {
    return NS_ERROR_NOT_INITIALIZED;
  }

  MOZ_ASSERT(&aTagName == nsGkAtoms::dt ||
             &aTagName == nsGkAtoms::dd);

  // Protect the edit rules object from dying
  RefPtr<TextEditRules> rules(mRules);

  bool cancel, handled;

  AutoPlaceholderBatch beginBatching(this);
  AutoTopLevelEditSubActionNotifier
    maybeTopLevelEditSubAction(*this,
                               EditSubAction::eCreateOrChangeDefinitionList,
                               nsIEditor::eNext);

  // pre-process
  RefPtr<Selection> selection = GetSelection();
  if (NS_WARN_IF(!selection)) {
    return NS_ERROR_FAILURE;
  }
  nsDependentAtomString tagName(&aTagName);
  EditSubActionInfo subActionInfo(EditSubAction::eCreateOrChangeDefinitionList);
  subActionInfo.blockType = &tagName;
  nsresult rv =
    rules->WillDoAction(selection, subActionInfo, &cancel, &handled);
  if (cancel || NS_FAILED(rv)) {
    return rv;
  }

  if (!handled) {
    // todo: no default for now.  we count on rules to handle it.
  }

  return rules->DidDoAction(selection, subActionInfo, rv);
}

nsresult
HTMLEditor::InsertBasicBlockWithTransaction(nsAtom& aTagName)
{
  if (!mRules) {
    return NS_ERROR_NOT_INITIALIZED;
  }

  MOZ_ASSERT(&aTagName != nsGkAtoms::dd &&
             &aTagName != nsGkAtoms::dt);

  // Protect the edit rules object from dying
  RefPtr<TextEditRules> rules(mRules);

  bool cancel, handled;

  AutoPlaceholderBatch beginBatching(this);
  AutoTopLevelEditSubActionNotifier maybeTopLevelEditSubAction(
                                      *this,
                                      EditSubAction::eCreateOrRemoveBlock,
                                      nsIEditor::eNext);

  // pre-process
  RefPtr<Selection> selection = GetSelection();
  NS_ENSURE_TRUE(selection, NS_ERROR_NULL_POINTER);
  nsDependentAtomString tagName(&aTagName);
  EditSubActionInfo subActionInfo(EditSubAction::eCreateOrRemoveBlock);
  subActionInfo.blockType = &tagName;
  nsresult rv =
   rules->WillDoAction(selection, subActionInfo, &cancel, &handled);
  if (cancel || NS_FAILED(rv)) {
    return rv;
  }

  if (!handled && selection->IsCollapsed()) {
    nsRange* firstRange = selection->GetRangeAt(0);
    if (NS_WARN_IF(!firstRange)) {
      return NS_ERROR_FAILURE;
    }

    EditorRawDOMPoint atStartOfSelection(firstRange->StartRef());
    if (NS_WARN_IF(!atStartOfSelection.IsSet()) ||
        NS_WARN_IF(!atStartOfSelection.GetContainerAsContent())) {
      return NS_ERROR_FAILURE;
    }

    // Have to find a place to put the block.
    EditorDOMPoint pointToInsertBlock(atStartOfSelection);

    while (!CanContainTag(*pointToInsertBlock.GetContainer(), aTagName)) {
      pointToInsertBlock.Set(pointToInsertBlock.GetContainer());
      if (NS_WARN_IF(!pointToInsertBlock.IsSet()) ||
          NS_WARN_IF(!pointToInsertBlock.GetContainerAsContent())) {
        return NS_ERROR_FAILURE;
      }
    }

    if (pointToInsertBlock.GetContainer() !=
          atStartOfSelection.GetContainer()) {
      // We need to split up to the child of the point to insert a block.
      SplitNodeResult splitBlockResult =
        SplitNodeDeepWithTransaction(
          *pointToInsertBlock.GetChild(), atStartOfSelection,
          SplitAtEdges::eAllowToCreateEmptyContainer);
      if (NS_WARN_IF(splitBlockResult.Failed())) {
        return splitBlockResult.Rv();
      }
      pointToInsertBlock = splitBlockResult.SplitPoint();
      if (NS_WARN_IF(!pointToInsertBlock.IsSet())) {
        return NS_ERROR_FAILURE;
      }
    }

    // Create a block and insert it before the right node if we split some
    // parents of start of selection above, or just start of selection
    // otherwise.
    RefPtr<Element> newBlock =
      CreateNodeWithTransaction(aTagName, pointToInsertBlock);
    if (NS_WARN_IF(!newBlock)) {
      return NS_ERROR_FAILURE;
    }

    // reposition selection to inside the block
    ErrorResult error;
    selection->Collapse(RawRangeBoundary(newBlock, 0), error);
    if (NS_WARN_IF(error.Failed())) {
      return error.StealNSResult();
    }
  }

  return rules->DidDoAction(selection, subActionInfo, rv);
}

NS_IMETHODIMP
HTMLEditor::Indent(const nsAString& aIndent)
{
  if (!mRules) {
    return NS_ERROR_NOT_INITIALIZED;
  }

  // Protect the edit rules object from dying
  RefPtr<TextEditRules> rules(mRules);

  bool cancel, handled;
  EditSubAction indentOrOutdent =
    aIndent.LowerCaseEqualsLiteral("outdent") ? EditSubAction::eOutdent :
                                                EditSubAction::eIndent;
  AutoPlaceholderBatch beginBatching(this);
  AutoTopLevelEditSubActionNotifier maybeTopLevelEditSubAction(
                                      *this, indentOrOutdent, nsIEditor::eNext);

  // pre-process
  RefPtr<Selection> selection = GetSelection();
  NS_ENSURE_TRUE(selection, NS_ERROR_NULL_POINTER);

  EditSubActionInfo subActionInfo(indentOrOutdent);
  nsresult rv =
    rules->WillDoAction(selection, subActionInfo, &cancel, &handled);
  if (cancel || NS_FAILED(rv)) {
    return rv;
  }

  if (!handled && selection->IsCollapsed() && aIndent.EqualsLiteral("indent")) {
    nsRange* firstRange = selection->GetRangeAt(0);
    if (NS_WARN_IF(!firstRange)) {
      return NS_ERROR_FAILURE;
    }

    EditorRawDOMPoint atStartOfSelection(firstRange->StartRef());
    if (NS_WARN_IF(!atStartOfSelection.IsSet()) ||
        NS_WARN_IF(!atStartOfSelection.GetContainerAsContent())) {
      return NS_ERROR_FAILURE;
    }

    // Have to find a place to put the blockquote.
    EditorDOMPoint pointToInsertBlockquote(atStartOfSelection);

    while (!CanContainTag(*pointToInsertBlockquote.GetContainer(),
                          *nsGkAtoms::blockquote)) {
      pointToInsertBlockquote.Set(pointToInsertBlockquote.GetContainer());
      if (NS_WARN_IF(!pointToInsertBlockquote.IsSet()) ||
          NS_WARN_IF(!pointToInsertBlockquote.GetContainerAsContent())) {
        return NS_ERROR_FAILURE;
      }
    }

    if (pointToInsertBlockquote.GetContainer() !=
          atStartOfSelection.GetContainer()) {
      // We need to split up to the child of parent.
      SplitNodeResult splitBlockquoteResult =
        SplitNodeDeepWithTransaction(
          *pointToInsertBlockquote.GetChild(), atStartOfSelection,
          SplitAtEdges::eAllowToCreateEmptyContainer);
      if (NS_WARN_IF(splitBlockquoteResult.Failed())) {
        return splitBlockquoteResult.Rv();
      }
      pointToInsertBlockquote = splitBlockquoteResult.SplitPoint();
      if (NS_WARN_IF(!pointToInsertBlockquote.IsSet())) {
        return NS_ERROR_FAILURE;
      }
    }

    // Create a list and insert it before the right node if we split some
    // parents of start of selection above, or just start of selection
    // otherwise.
    RefPtr<Element> newBQ =
      CreateNodeWithTransaction(*nsGkAtoms::blockquote,
                                pointToInsertBlockquote);
    if (NS_WARN_IF(!newBQ)) {
      return NS_ERROR_FAILURE;
    }
    // put a space in it so layout will draw the list item
    ErrorResult error;
    selection->Collapse(RawRangeBoundary(newBQ, 0), error);
    if (NS_WARN_IF(error.Failed())) {
      return error.StealNSResult();
    }
    rv = InsertTextAsSubAction(NS_LITERAL_STRING(" "));
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }
    // Reposition selection to before the space character.
    firstRange = selection->GetRangeAt(0);
    if (NS_WARN_IF(!firstRange)) {
      return NS_ERROR_FAILURE;
    }
    selection->Collapse(RawRangeBoundary(firstRange->GetStartContainer(), 0),
                        error);
    if (NS_WARN_IF(error.Failed())) {
      return error.StealNSResult();
    }
  }
  return rules->DidDoAction(selection, subActionInfo, rv);
}

//TODO: IMPLEMENT ALIGNMENT!

NS_IMETHODIMP
HTMLEditor::Align(const nsAString& aAlignType)
{
  // Protect the edit rules object from dying
  RefPtr<TextEditRules> rules(mRules);

  AutoPlaceholderBatch beginBatching(this);
  AutoTopLevelEditSubActionNotifier maybeTopLevelEditSubAction(
                                      *this,
                                      EditSubAction::eSetOrClearAlignment,
                                      nsIEditor::eNext);

  bool cancel, handled;

  // Find out if the selection is collapsed:
  RefPtr<Selection> selection = GetSelection();
  NS_ENSURE_TRUE(selection, NS_ERROR_NULL_POINTER);
  EditSubActionInfo subActionInfo(EditSubAction::eSetOrClearAlignment);
  subActionInfo.alignType = &aAlignType;
  nsresult rv =
   rules->WillDoAction(selection, subActionInfo, &cancel, &handled);
  if (cancel || NS_FAILED(rv)) {
    return rv;
  }

  return rules->DidDoAction(selection, subActionInfo, rv);
}

already_AddRefed<Element>
HTMLEditor::GetElementOrParentByTagName(const nsAString& aTagName,
                                        nsINode* aNode)
{
  MOZ_ASSERT(!aTagName.IsEmpty());

  nsCOMPtr<nsINode> node = aNode;
  if (!node) {
    // If no node supplied, get it from anchor node of current selection
    RefPtr<Selection> selection = GetSelection();
    if (NS_WARN_IF(!selection)) {
      return nullptr;
    }

    const EditorDOMPoint atAnchor(selection->AnchorRef());
    if (NS_WARN_IF(!atAnchor.IsSet())) {
      return nullptr;
    }

    // Try to get the actual selected node
    if (atAnchor.GetContainer()->HasChildNodes() &&
        atAnchor.GetContainerAsContent()) {
      node = atAnchor.GetChild();
    }
    // Anchor node is probably a text node - just use that
    if (!node) {
      node = atAnchor.GetContainer();
    }
  }

  nsCOMPtr<Element> current;
  if (node->IsElement()) {
    current = node->AsElement();
  } else if (node->GetParentElement()) {
    current = node->GetParentElement();
  } else {
    // Neither aNode nor its parent is an element, so no ancestor is
    MOZ_ASSERT(!node->GetParentNode() ||
               !node->GetParentNode()->GetParentNode());
    return nullptr;
  }

  nsAutoString tagName(aTagName);
  ToLowerCase(tagName);
  bool getLink = IsLinkTag(tagName);
  bool getNamedAnchor = IsNamedAnchorTag(tagName);
  if (getLink || getNamedAnchor) {
    tagName.Assign('a');
  }
  bool findTableCell = tagName.EqualsLiteral("td");
  bool findList = tagName.EqualsLiteral("list");

  for (; current; current = current->GetParentElement()) {
    // Test if we have a link (an anchor with href set)
    if ((getLink && HTMLEditUtils::IsLink(current)) ||
        (getNamedAnchor && HTMLEditUtils::IsNamedAnchor(current))) {
      return current.forget();
    }
    if (findList) {
      // Match "ol", "ul", or "dl" for lists
      if (HTMLEditUtils::IsList(current)) {
        return current.forget();
      }
    } else if (findTableCell) {
      // Table cells are another special case: match either "td" or "th"
      if (HTMLEditUtils::IsTableCell(current)) {
        return current.forget();
      }
    } else if (current->NodeName().Equals(tagName,
                   nsCaseInsensitiveStringComparator())) {
      return current.forget();
    }

    // Stop searching if parent is a body tag.  Note: Originally used IsRoot to
    // stop at table cells, but that's too messy when you are trying to find
    // the parent table
    if (current->GetParentElement() &&
        current->GetParentElement()->IsHTMLElement(nsGkAtoms::body)) {
      break;
    }
  }

  return nullptr;
}

NS_IMETHODIMP
HTMLEditor::GetElementOrParentByTagName(const nsAString& aTagName,
                                        nsINode* aNode,
                                        Element** aReturn)
{
  NS_ENSURE_TRUE(!aTagName.IsEmpty(), NS_ERROR_NULL_POINTER);
  NS_ENSURE_TRUE(aReturn, NS_ERROR_NULL_POINTER);

  RefPtr<Element> parent = GetElementOrParentByTagName(aTagName, aNode);

  if (!parent) {
    return NS_SUCCESS_EDITOR_ELEMENT_NOT_FOUND;
  }

  parent.forget(aReturn);
  return NS_OK;
}

NS_IMETHODIMP
HTMLEditor::GetSelectedElement(const nsAString& aTagName,
                               nsISupports** aReturn)
{
  NS_ENSURE_TRUE(aReturn , NS_ERROR_NULL_POINTER);

  // default is null - no element found
  *aReturn = nullptr;

  // First look for a single element in selection
  RefPtr<Selection> selection = GetSelection();
  NS_ENSURE_TRUE(selection, NS_ERROR_NULL_POINTER);

  bool isCollapsed = selection->IsCollapsed();

  nsAutoString domTagName;
  nsAutoString TagName(aTagName);
  ToLowerCase(TagName);
  // Empty string indicates we should match any element tag
  bool anyTag = (TagName.IsEmpty());
  bool isLinkTag = IsLinkTag(TagName);
  bool isNamedAnchorTag = IsNamedAnchorTag(TagName);

  RefPtr<nsRange> range = selection->GetRangeAt(0);
  NS_ENSURE_STATE(range);

  nsCOMPtr<nsINode> startContainer = range->GetStartContainer();
  nsIContent* startNode = range->GetChildAtStartOffset();

  nsCOMPtr<nsINode> endContainer = range->GetEndContainer();
  nsIContent* endNode = range->GetChildAtEndOffset();

  // Optimization for a single selected element
  if (startContainer && startContainer == endContainer &&
      startNode && endNode && startNode->GetNextSibling() == endNode) {
    nsCOMPtr<nsINode> selectedNode = startNode;
    if (selectedNode) {
      domTagName = selectedNode->NodeName();
      ToLowerCase(domTagName);

      // Test for appropriate node type requested
      if (anyTag || (TagName == domTagName) ||
          (isLinkTag && HTMLEditUtils::IsLink(selectedNode)) ||
          (isNamedAnchorTag && HTMLEditUtils::IsNamedAnchor(selectedNode))) {
        selectedNode.forget(aReturn);
        return NS_OK;
      }
    }
  }

  bool bNodeFound = false;
  nsCOMPtr<Element> selectedElement;
  if (isLinkTag) {
    // Link tag is a special case - we return the anchor node
    //  found for any selection that is totally within a link,
    //  included a collapsed selection (just a caret in a link)
    const RangeBoundary& anchor = selection->AnchorRef();
    const RangeBoundary& focus = selection->FocusRef();
    // Link node must be the same for both ends of selection
    if (anchor.IsSet()) {
      RefPtr<Element> parentLinkOfAnchor =
        GetElementOrParentByTagName(NS_LITERAL_STRING("href"),
                                    anchor.Container());
      // XXX: ERROR_HANDLING  can parentLinkOfAnchor be null?
      if (parentLinkOfAnchor) {
        if (isCollapsed) {
          // We have just a caret in the link
          bNodeFound = true;
        } else if (focus.IsSet()) {
          // Link node must be the same for both ends of selection.
          RefPtr<Element> parentLinkOfFocus =
            GetElementOrParentByTagName(NS_LITERAL_STRING("href"),
                                        focus.Container());
          if (parentLinkOfFocus == parentLinkOfAnchor) {
            bNodeFound = true;
          }
        }

        // We found a link node parent
        if (bNodeFound) {
          parentLinkOfAnchor.forget(aReturn);
          return NS_OK;
        }
      } else if (anchor.GetChildAtOffset() && focus.GetChildAtOffset()) {
        // Check if link node is the only thing selected
        if (HTMLEditUtils::IsLink(anchor.GetChildAtOffset()) &&
            anchor.Container() == focus.Container() &&
            focus.GetChildAtOffset() ==
              anchor.GetChildAtOffset()->GetNextSibling()) {
          selectedElement = do_QueryInterface(anchor.GetChildAtOffset());
          bNodeFound = true;
        }
      }
    }
  }

  if (!isCollapsed) {
    RefPtr<nsRange> currange = selection->GetRangeAt(0);
    if (currange) {
      nsresult rv;
      nsCOMPtr<nsIContentIterator> iter =
        do_CreateInstance("@mozilla.org/content/post-content-iterator;1",
                          &rv);
      NS_ENSURE_SUCCESS(rv, rv);

      iter->Init(currange);
      // loop through the content iterator for each content node
      while (!iter->IsDone()) {
        // Query interface to cast nsIContent to Element
        //  then get tagType to compare to  aTagName
        // Clone node of each desired type and append it to the aDomFrag
        selectedElement = Element::FromNodeOrNull(iter->GetCurrentNode());
        if (selectedElement) {
          // If we already found a node, then we have another element,
          //  thus there's not just one element selected
          if (bNodeFound) {
            bNodeFound = false;
            break;
          }

          domTagName = selectedElement->NodeName();
          ToLowerCase(domTagName);

          if (anyTag) {
            // Get name of first selected element
            selectedElement->GetTagName(TagName);
            ToLowerCase(TagName);
            anyTag = false;
          }

          // The "A" tag is a pain,
          //  used for both link(href is set) and "Named Anchor"
          if ((isLinkTag &&
               HTMLEditUtils::IsLink(selectedElement)) ||
              (isNamedAnchorTag &&
               HTMLEditUtils::IsNamedAnchor(selectedElement))) {
            bNodeFound = true;
          } else if (TagName == domTagName) { // All other tag names are handled here
            bNodeFound = true;
          }
          if (!bNodeFound) {
            // Check if node we have is really part of the selection???
            break;
          }
        }
        iter->Next();
      }
    } else {
      // Should never get here?
      isCollapsed = true;
      NS_WARNING("isCollapsed was FALSE, but no elements found in selection\n");
    }
  }

  selectedElement.forget(aReturn);
  return NS_OK;
}

already_AddRefed<Element>
HTMLEditor::GetSelectedElement(const nsAString& aTagName)
{
  nsCOMPtr<nsISupports> domElement;
  GetSelectedElement(aTagName, getter_AddRefs(domElement));
  nsCOMPtr<Element> element = do_QueryInterface(domElement);
  return element.forget();
}

already_AddRefed<Element>
HTMLEditor::CreateElementWithDefaults(const nsAString& aTagName)
{
  MOZ_ASSERT(!aTagName.IsEmpty());

  nsAutoString tagName(aTagName);
  ToLowerCase(tagName);
  nsAutoString realTagName;

  if (IsLinkTag(tagName) || IsNamedAnchorTag(tagName)) {
    realTagName.Assign('a');
  } else {
    realTagName = tagName;
  }
  // We don't use editor's CreateElement because we don't want to go through
  // the transaction system

  // New call to use instead to get proper HTML element, bug 39919
  RefPtr<nsAtom> realTagAtom = NS_Atomize(realTagName);
  RefPtr<Element> newElement = CreateHTMLContent(realTagAtom);
  if (!newElement) {
    return nullptr;
  }

  // Mark the new element dirty, so it will be formatted
  ErrorResult rv;
  newElement->SetAttribute(NS_LITERAL_STRING("_moz_dirty"), EmptyString(), rv);

  // Set default values for new elements
  if (tagName.EqualsLiteral("table")) {
    newElement->SetAttribute(NS_LITERAL_STRING("cellpadding"),
                             NS_LITERAL_STRING("2"), rv);
    if (NS_WARN_IF(rv.Failed())) {
      rv.SuppressException();
      return nullptr;
    }
    newElement->SetAttribute(NS_LITERAL_STRING("cellspacing"),
                             NS_LITERAL_STRING("2"), rv);
    if (NS_WARN_IF(rv.Failed())) {
      rv.SuppressException();
      return nullptr;
    }
    newElement->SetAttribute(NS_LITERAL_STRING("border"),
                             NS_LITERAL_STRING("1"), rv);
    if (NS_WARN_IF(rv.Failed())) {
      rv.SuppressException();
      return nullptr;
    }
  } else if (tagName.EqualsLiteral("td")) {
    nsresult rv =
      SetAttributeOrEquivalent(
        newElement, nsGkAtoms::valign, NS_LITERAL_STRING("top"), true);
    NS_ENSURE_SUCCESS(rv, nullptr);
  }
  // ADD OTHER TAGS HERE

  return newElement.forget();
}

NS_IMETHODIMP
HTMLEditor::CreateElementWithDefaults(const nsAString& aTagName,
                                      Element** aReturn)
{
  NS_ENSURE_TRUE(!aTagName.IsEmpty() && aReturn, NS_ERROR_NULL_POINTER);
  *aReturn = nullptr;

  nsCOMPtr<Element> newElement = CreateElementWithDefaults(aTagName);
  NS_ENSURE_TRUE(newElement, NS_ERROR_FAILURE);

  newElement.forget(aReturn);
  return NS_OK;
}

NS_IMETHODIMP
HTMLEditor::InsertLinkAroundSelection(Element* aAnchorElement)
{
  NS_ENSURE_TRUE(aAnchorElement, NS_ERROR_NULL_POINTER);

  // We must have a real selection
  RefPtr<Selection> selection = GetSelection();
  NS_ENSURE_TRUE(selection, NS_ERROR_NULL_POINTER);

  if (selection->IsCollapsed()) {
    NS_WARNING("InsertLinkAroundSelection called but there is no selection!!!");
    return NS_OK;
  }


  // Be sure we were given an anchor element
  RefPtr<HTMLAnchorElement> anchor =
    HTMLAnchorElement::FromNodeOrNull(aAnchorElement);
  if (!anchor) {
    return NS_OK;
  }

  nsAutoString href;
  anchor->GetHref(href);
  if (href.IsEmpty()) {
    return NS_OK;
  }

  nsresult rv;
  AutoPlaceholderBatch beginBatching(this);

  // Set all attributes found on the supplied anchor element
  RefPtr<nsDOMAttributeMap> attrMap = anchor->Attributes();
  NS_ENSURE_TRUE(attrMap, NS_ERROR_FAILURE);

  uint32_t count = attrMap->Length();
  nsAutoString value;

  for (uint32_t i = 0; i < count; ++i) {
    RefPtr<Attr> attribute = attrMap->Item(i);

    if (attribute) {
      // We must clear the string buffers
      //   because GetValue appends to previous string!
      value.Truncate();

      nsAtom* name = attribute->NodeInfo()->NameAtom();

      attribute->GetValue(value);

      rv = SetInlinePropertyInternal(*nsGkAtoms::a, name, value);
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }
    }
  }
  return NS_OK;
}

nsresult
HTMLEditor::SetHTMLBackgroundColorWithTransaction(const nsAString& aColor)
{
  MOZ_ASSERT(IsInitialized(), "The HTMLEditor hasn't been initialized yet");

  // Find a selected or enclosing table element to set background on
  RefPtr<Element> element;
  int32_t selectedCount;
  nsAutoString tagName;
  nsresult rv = GetSelectedOrParentTableElement(tagName, &selectedCount,
                                                getter_AddRefs(element));
  NS_ENSURE_SUCCESS(rv, rv);

  bool setColor = !aColor.IsEmpty();

  RefPtr<nsAtom> bgColorAtom = NS_Atomize("bgcolor");
  if (element) {
    if (selectedCount > 0) {
      // Traverse all selected cells
      RefPtr<Element> cell;
      rv = GetFirstSelectedCell(nullptr, getter_AddRefs(cell));
      if (NS_SUCCEEDED(rv) && cell) {
        while (cell) {
          rv = setColor ?
                 SetAttributeWithTransaction(*cell, *bgColorAtom, aColor) :
                 RemoveAttributeWithTransaction(*cell, *bgColorAtom);
          if (NS_FAILED(rv)) {
            return rv;
          }
          GetNextSelectedCell(nullptr, getter_AddRefs(cell));
        }
        return NS_OK;
      }
    }
    // If we failed to find a cell, fall through to use originally-found element
  } else {
    // No table element -- set the background color on the body tag
    element = GetRoot();
    if (NS_WARN_IF(!element)) {
      return NS_ERROR_FAILURE;
    }
  }
  // Use the editor method that goes through the transaction system
  return setColor ?
           SetAttributeWithTransaction(*element, *bgColorAtom, aColor) :
           RemoveAttributeWithTransaction(*element, *bgColorAtom);
}

NS_IMETHODIMP
HTMLEditor::GetLinkedObjects(nsIArray** aNodeList)
{
  NS_ENSURE_TRUE(aNodeList, NS_ERROR_NULL_POINTER);

  nsresult rv;
  nsCOMPtr<nsIMutableArray> nodes = do_CreateInstance(NS_ARRAY_CONTRACTID, &rv);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  nsCOMPtr<nsIContentIterator> iter =
    do_CreateInstance("@mozilla.org/content/post-content-iterator;1", &rv);
  NS_ENSURE_TRUE(iter, NS_ERROR_NULL_POINTER);
  if (NS_SUCCEEDED(rv)) {
    nsCOMPtr<nsIDocument> doc = GetDocument();
    NS_ENSURE_TRUE(doc, NS_ERROR_UNEXPECTED);

    iter->Init(doc->GetRootElement());

    // loop through the content iterator for each content node
    while (!iter->IsDone()) {
      nsCOMPtr<nsINode> node = iter->GetCurrentNode();
      if (node) {
        // Let nsURIRefObject make the hard decisions:
        nsCOMPtr<nsIURIRefObject> refObject;
        rv = NS_NewHTMLURIRefObject(getter_AddRefs(refObject), node);
        if (NS_SUCCEEDED(rv)) {
          nodes->AppendElement(refObject);
        }
      }
      iter->Next();
    }
  }

  nodes.forget(aNodeList);
  return NS_OK;
}


NS_IMETHODIMP
HTMLEditor::AddOverrideStyleSheet(const nsAString& aURL)
{
  // Enable existing sheet if already loaded.
  if (EnableExistingStyleSheet(aURL)) {
    return NS_OK;
  }

  // Make sure the pres shell doesn't disappear during the load.
  nsCOMPtr<nsIPresShell> ps = GetPresShell();
  NS_ENSURE_TRUE(ps, NS_ERROR_NOT_INITIALIZED);

  nsCOMPtr<nsIURI> uaURI;
  nsresult rv = NS_NewURI(getter_AddRefs(uaURI), aURL);
  NS_ENSURE_SUCCESS(rv, rv);

  // We MUST ONLY load synchronous local files (no @import)
  // XXXbz Except this will actually try to load remote files
  // synchronously, of course..
  RefPtr<StyleSheet> sheet;
  // Editor override style sheets may want to style Gecko anonymous boxes
  rv = ps->GetDocument()->CSSLoader()->
    LoadSheetSync(uaURI, mozilla::css::eAgentSheetFeatures, true,
                  &sheet);

  // Synchronous loads should ALWAYS return completed
  NS_ENSURE_TRUE(sheet, NS_ERROR_NULL_POINTER);

  // Add the override style sheet
  // (This checks if already exists)
  ps->AddOverrideStyleSheet(sheet);
  ps->ApplicableStylesChanged();

  // Save as the last-loaded sheet
  mLastOverrideStyleSheetURL = aURL;

  //Add URL and style sheet to our lists
  return AddNewStyleSheetToList(aURL, sheet);
}

NS_IMETHODIMP
HTMLEditor::ReplaceOverrideStyleSheet(const nsAString& aURL)
{
  // Enable existing sheet if already loaded.
  if (EnableExistingStyleSheet(aURL)) {
    // Disable last sheet if not the same as new one
    if (!mLastOverrideStyleSheetURL.IsEmpty() &&
        !mLastOverrideStyleSheetURL.Equals(aURL)) {
      return EnableStyleSheet(mLastOverrideStyleSheetURL, false);
    }
    return NS_OK;
  }
  // Remove the previous sheet
  if (!mLastOverrideStyleSheetURL.IsEmpty()) {
    RemoveOverrideStyleSheet(mLastOverrideStyleSheetURL);
  }
  return AddOverrideStyleSheet(aURL);
}

// Do NOT use transaction system for override style sheets
NS_IMETHODIMP
HTMLEditor::RemoveOverrideStyleSheet(const nsAString& aURL)
{
  RefPtr<StyleSheet> sheet = GetStyleSheetForURL(aURL);

  // Make sure we remove the stylesheet from our internal list in all
  // cases.
  nsresult rv = RemoveStyleSheetFromList(aURL);

  NS_ENSURE_TRUE(sheet, NS_OK); /// Don't fail if sheet not found

  if (NS_WARN_IF(!IsInitialized())) {
    return NS_ERROR_NOT_INITIALIZED;
  }
  nsCOMPtr<nsIPresShell> ps = GetPresShell();
  NS_ENSURE_TRUE(ps, NS_ERROR_NOT_INITIALIZED);

  ps->RemoveOverrideStyleSheet(sheet);
  ps->ApplicableStylesChanged();

  // Remove it from our internal list
  return rv;
}

NS_IMETHODIMP
HTMLEditor::EnableStyleSheet(const nsAString& aURL, bool aEnable)
{
  RefPtr<StyleSheet> sheet = GetStyleSheetForURL(aURL);
  NS_ENSURE_TRUE(sheet, NS_OK); // Don't fail if sheet not found

  // Ensure the style sheet is owned by our document.
  nsCOMPtr<nsIDocument> document = GetDocument();
  sheet->SetAssociatedDocumentOrShadowRoot(
    document, StyleSheet::NotOwnedByDocumentOrShadowRoot);

  sheet->SetDisabled(!aEnable);
  return NS_OK;
}

bool
HTMLEditor::EnableExistingStyleSheet(const nsAString& aURL)
{
  RefPtr<StyleSheet> sheet = GetStyleSheetForURL(aURL);

  // Enable sheet if already loaded.
  if (!sheet) {
    return false;
  }

  // Ensure the style sheet is owned by our document.
  nsCOMPtr<nsIDocument> document = GetDocument();
  sheet->SetAssociatedDocumentOrShadowRoot(
    document, StyleSheet::NotOwnedByDocumentOrShadowRoot);

  // FIXME: This used to do sheet->SetDisabled(false), figure out if we can
  // just remove all this code in bug 1449522, since it seems unused.
  return true;
}

nsresult
HTMLEditor::AddNewStyleSheetToList(const nsAString& aURL,
                                   StyleSheet* aStyleSheet)
{
  uint32_t countSS = mStyleSheets.Length();
  uint32_t countU = mStyleSheetURLs.Length();

  if (countSS != countU) {
    return NS_ERROR_UNEXPECTED;
  }

  if (!mStyleSheetURLs.AppendElement(aURL)) {
    return NS_ERROR_UNEXPECTED;
  }

  return mStyleSheets.AppendElement(aStyleSheet) ? NS_OK : NS_ERROR_UNEXPECTED;
}

nsresult
HTMLEditor::RemoveStyleSheetFromList(const nsAString& aURL)
{
  // is it already in the list?
  size_t foundIndex;
  foundIndex = mStyleSheetURLs.IndexOf(aURL);
  if (foundIndex == mStyleSheetURLs.NoIndex) {
    return NS_ERROR_FAILURE;
  }

  // Attempt both removals; if one fails there's not much we can do.
  mStyleSheets.RemoveElementAt(foundIndex);
  mStyleSheetURLs.RemoveElementAt(foundIndex);

  return NS_OK;
}

StyleSheet*
HTMLEditor::GetStyleSheetForURL(const nsAString& aURL)
{
  // is it already in the list?
  size_t foundIndex;
  foundIndex = mStyleSheetURLs.IndexOf(aURL);
  if (foundIndex == mStyleSheetURLs.NoIndex) {
    return nullptr;
  }

  MOZ_ASSERT(mStyleSheets[foundIndex]);
  return mStyleSheets[foundIndex];
}

void
HTMLEditor::GetURLForStyleSheet(StyleSheet* aStyleSheet,
                                nsAString& aURL)
{
  // is it already in the list?
  int32_t foundIndex = mStyleSheets.IndexOf(aStyleSheet);

  // Don't fail if we don't find it in our list
  if (foundIndex == -1) {
    return;
  }

  // Found it in the list!
  aURL = mStyleSheetURLs[foundIndex];
}

NS_IMETHODIMP
HTMLEditor::GetEmbeddedObjects(nsIArray** aNodeList)
{
  if (NS_WARN_IF(!aNodeList)) {
    return NS_ERROR_INVALID_ARG;
  }

  nsresult rv;
  nsCOMPtr<nsIMutableArray> nodes = do_CreateInstance(NS_ARRAY_CONTRACTID, &rv);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  nsCOMPtr<nsIContentIterator> iter =
    do_CreateInstance("@mozilla.org/content/post-content-iterator;1", &rv);
  if (NS_WARN_IF(!iter)) {
    return NS_ERROR_FAILURE;
  }
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  nsCOMPtr<nsIDocument> doc = GetDocument();
  if (NS_WARN_IF(!doc)) {
    return NS_ERROR_UNEXPECTED;
  }

  iter->Init(doc->GetRootElement());

  // Loop through the content iterator for each content node.
  while (!iter->IsDone()) {
    nsINode* node = iter->GetCurrentNode();
    if (node->IsElement()) {
      dom::Element* element = node->AsElement();

      // See if it's an image or an embed and also include all links.
      // Let mail decide which link to send or not
      if (element->IsAnyOfHTMLElements(nsGkAtoms::img, nsGkAtoms::embed,
                                       nsGkAtoms::a) ||
          (element->IsHTMLElement(nsGkAtoms::body) &&
           element->HasAttr(kNameSpaceID_None, nsGkAtoms::background))) {
        nodes->AppendElement(node);
       }
     }
     iter->Next();
   }

  nodes.forget(aNodeList);
  return NS_OK;
}

nsresult
HTMLEditor::DeleteSelectionWithTransaction(EDirection aAction,
                                           EStripWrappers aStripWrappers)
{
  MOZ_ASSERT(aStripWrappers == eStrip || aStripWrappers == eNoStrip);

  nsresult rv =
    TextEditor::DeleteSelectionWithTransaction(aAction, aStripWrappers);
  NS_ENSURE_SUCCESS(rv, rv);

  // If we weren't asked to strip any wrappers, we're done.
  if (aStripWrappers == eNoStrip) {
    return NS_OK;
  }

  RefPtr<Selection> selection = GetSelection();
  // Just checking that the selection itself is collapsed doesn't seem to work
  // right in the multi-range case
  NS_ENSURE_STATE(selection);
  NS_ENSURE_STATE(selection->GetAnchorFocusRange());
  NS_ENSURE_STATE(selection->GetAnchorFocusRange()->Collapsed());

  NS_ENSURE_STATE(selection->GetAnchorNode()->IsContent());
  nsCOMPtr<nsIContent> content = selection->GetAnchorNode()->AsContent();

  // Don't strip wrappers if this is the only wrapper in the block.  Then we'll
  // add a <br> later, so it won't be an empty wrapper in the end.
  nsCOMPtr<nsIContent> blockParent = content;
  while (blockParent && !IsBlockNode(blockParent)) {
    blockParent = blockParent->GetParent();
  }
  if (!blockParent) {
    return NS_OK;
  }
  bool emptyBlockParent;
  rv = IsEmptyNode(blockParent, &emptyBlockParent);
  NS_ENSURE_SUCCESS(rv, rv);
  if (emptyBlockParent) {
    return NS_OK;
  }

  if (content && !IsBlockNode(content) && !content->Length() &&
      content->IsEditable() && content != content->GetEditingHost()) {
    while (content->GetParent() && !IsBlockNode(content->GetParent()) &&
           content->GetParent()->Length() == 1 &&
           content->GetParent()->IsEditable() &&
           content->GetParent() != content->GetEditingHost()) {
      content = content->GetParent();
    }
    rv = DeleteNodeWithTransaction(*content);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  return NS_OK;
}

nsresult
HTMLEditor::DeleteNodeWithTransaction(nsINode& aNode)
{
  if (NS_WARN_IF(!aNode.IsContent())) {
    return NS_ERROR_INVALID_ARG;
  }
  // Do nothing if the node is read-only.
  // XXX This is not a override method of EditorBase's method.  This might
  //     cause not called accidentally.  We need to investigate this issue.
  if (NS_WARN_IF(!IsModifiableNode(*aNode.AsContent()) &&
                 !IsMozEditorBogusNode(aNode.AsContent()))) {
    return NS_ERROR_FAILURE;
  }
  nsresult rv = EditorBase::DeleteNodeWithTransaction(aNode);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }
  return NS_OK;
}

NS_IMETHODIMP
HTMLEditor::DeleteNode(nsINode* aNode)
{
  if (NS_WARN_IF(!aNode)) {
    return NS_ERROR_INVALID_ARG;
  }
  nsresult rv = DeleteNodeWithTransaction(*aNode);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }
  return NS_OK;
}

nsresult
HTMLEditor::DeleteTextWithTransaction(CharacterData& aCharData,
                                      uint32_t aOffset,
                                      uint32_t aLength)
{
  // Do nothing if the node is read-only
  if (!IsModifiableNode(aCharData)) {
    return NS_ERROR_FAILURE;
  }

  return EditorBase::DeleteTextWithTransaction(aCharData, aOffset, aLength);
}

nsresult
HTMLEditor::InsertTextWithTransaction(
              nsIDocument& aDocument,
              const nsAString& aStringToInsert,
              const EditorRawDOMPoint& aPointToInsert,
              EditorRawDOMPoint* aPointAfterInsertedString)
{
  if (NS_WARN_IF(!aPointToInsert.IsSet())) {
    return NS_ERROR_INVALID_ARG;
  }

  // Do nothing if the node is read-only
  if (!IsModifiableNode(*aPointToInsert.GetContainer())) {
    return NS_ERROR_FAILURE;
  }

  return EditorBase::InsertTextWithTransaction(aDocument, aStringToInsert,
                                               aPointToInsert,
                                               aPointAfterInsertedString);
}

void
HTMLEditor::ContentAppended(nsIContent* aFirstNewContent)
{
  DoContentInserted(aFirstNewContent, eAppended);
}

void
HTMLEditor::ContentInserted(nsIContent* aChild)
{
  DoContentInserted(aChild, eInserted);
}

bool
HTMLEditor::IsInObservedSubtree(nsIContent* aChild)
{
  if (!aChild) {
    return false;
  }

  Element* root = GetRoot();
  // To be super safe here, check both ChromeOnlyAccess and GetBindingParent.
  // That catches (also unbound) native anonymous content, XBL and ShadowDOM.
  if (root &&
      (root->ChromeOnlyAccess() != aChild->ChromeOnlyAccess() ||
       root->GetBindingParent() != aChild->GetBindingParent())) {
    return false;
  }

  return !aChild->ChromeOnlyAccess() && !aChild->GetBindingParent();
}

void
HTMLEditor::DoContentInserted(nsIContent* aChild,
                              InsertedOrAppended aInsertedOrAppended)
{
  MOZ_ASSERT(aChild);
  nsINode* container = aChild->GetParentNode();
  MOZ_ASSERT(container);

  if (!IsInObservedSubtree(aChild)) {
    return;
  }

  // XXX Why do we need this? This method is a helper of mutation observer.
  //     So, the callers of mutation observer should guarantee that this won't
  //     be deleted at least during the call.
  RefPtr<HTMLEditor> kungFuDeathGrip(this);

  if (ShouldReplaceRootElement()) {
    UpdateRootElement();
    nsContentUtils::AddScriptRunner(
      NewRunnableMethod("HTMLEditor::NotifyRootChanged",
                        this,
                        &HTMLEditor::NotifyRootChanged));
  }
  // We don't need to handle our own modifications
  else if (!mTopLevelEditSubAction && container->IsEditable()) {
    if (IsMozEditorBogusNode(aChild)) {
      // Ignore insertion of the bogus node
      return;
    }
    // Protect the edit rules object from dying
    RefPtr<TextEditRules> rules(mRules);
    rules->DocumentModified();

    // Update spellcheck for only the newly-inserted node (bug 743819)
    if (mInlineSpellChecker) {
      RefPtr<nsRange> range = new nsRange(aChild);
      nsIContent* endContent = aChild;
      if (aInsertedOrAppended == eAppended) {
        // Maybe more than 1 child was appended.
        endContent = container->GetLastChild();
      }
      range->SelectNodesInContainer(container, aChild, endContent);
      mInlineSpellChecker->SpellCheckRange(range);
    }
  }
}

void
HTMLEditor::ContentRemoved(nsIContent* aChild,
                           nsIContent* aPreviousSibling)
{
  if (!IsInObservedSubtree(aChild)) {
    return;
  }

  // XXX Why do we need to do this?  This method is a mutation observer's
  //     method.  Therefore, the caller should guarantee that this won't be
  //     deleted during the call.
  RefPtr<HTMLEditor> kungFuDeathGrip(this);

  if (SameCOMIdentity(aChild, mRootElement)) {
    mRootElement = nullptr;
    nsContentUtils::AddScriptRunner(
      NewRunnableMethod("HTMLEditor::NotifyRootChanged",
                        this,
                        &HTMLEditor::NotifyRootChanged));
  // We don't need to handle our own modifications
  } else if (!mTopLevelEditSubAction && aChild->GetParentNode()->IsEditable()) {
    if (aChild && IsMozEditorBogusNode(aChild)) {
      // Ignore removal of the bogus node
      return;
    }
    // Protect the edit rules object from dying
    RefPtr<TextEditRules> rules(mRules);
    rules->DocumentModified();
  }
}

NS_IMETHODIMP
HTMLEditor::DebugUnitTests(int32_t* outNumTests,
                           int32_t* outNumTestsFailed)
{
#ifdef DEBUG
  NS_ENSURE_TRUE(outNumTests && outNumTestsFailed, NS_ERROR_NULL_POINTER);

  TextEditorTest *tester = new TextEditorTest();
  NS_ENSURE_TRUE(tester, NS_ERROR_OUT_OF_MEMORY);

  tester->Run(this, outNumTests, outNumTestsFailed);
  delete tester;
  return NS_OK;
#else
  return NS_ERROR_NOT_IMPLEMENTED;
#endif
}

void
HTMLEditor::OnStartToHandleTopLevelEditSubAction(
              EditSubAction aEditSubAction,
              nsIEditor::EDirection aDirection)
{
  // Protect the edit rules object from dying
  RefPtr<TextEditRules> rules(mRules);

  EditorBase::OnStartToHandleTopLevelEditSubAction(aEditSubAction, aDirection);
  if (!rules) {
    return;
  }

  MOZ_ASSERT(mTopLevelEditSubAction == aEditSubAction);
  MOZ_ASSERT(mDirection == aDirection);
  DebugOnly<nsresult> rv =
    rules->BeforeEdit(mTopLevelEditSubAction, mDirection);
  NS_WARNING_ASSERTION(NS_SUCCEEDED(rv),
    "HTMLEditRules::BeforeEdit() failed to handle something");
}

void
HTMLEditor::OnEndHandlingTopLevelEditSubAction()
{
  // Protect the edit rules object from dying
  RefPtr<TextEditRules> rules(mRules);

  // post processing
  DebugOnly<nsresult> rv =
    rules ? rules->AfterEdit(mTopLevelEditSubAction, mDirection) : NS_OK;
  NS_WARNING_ASSERTION(NS_SUCCEEDED(rv),
    "HTMLEditRules::AfterEdit() failed to handle something");
  EditorBase::OnEndHandlingTopLevelEditSubAction();
  MOZ_ASSERT(!mTopLevelEditSubAction);
  MOZ_ASSERT(mDirection == eNone);
}

bool
HTMLEditor::TagCanContainTag(nsAtom& aParentTag,
                             nsAtom& aChildTag) const
{
  int32_t childTagEnum;
  // XXX Should this handle #cdata-section too?
  if (&aChildTag == nsGkAtoms::textTagName) {
    childTagEnum = eHTMLTag_text;
  } else {
    childTagEnum = nsHTMLTags::AtomTagToId(&aChildTag);
  }

  int32_t parentTagEnum = nsHTMLTags::AtomTagToId(&aParentTag);
  return HTMLEditUtils::CanContain(parentTagEnum, childTagEnum);
}

bool
HTMLEditor::IsContainer(nsINode* aNode)
{
  MOZ_ASSERT(aNode);

  int32_t tagEnum;
  // XXX Should this handle #cdata-section too?
  if (aNode->IsText()) {
    tagEnum = eHTMLTag_text;
  } else {
    tagEnum = nsHTMLTags::StringTagToId(aNode->NodeName());
  }

  return HTMLEditUtils::IsContainer(tagEnum);
}

nsresult
HTMLEditor::SelectEntireDocument(Selection* aSelection)
{
  if (!aSelection || !mRules) {
    return NS_ERROR_NULL_POINTER;
  }

  // Protect the edit rules object from dying
  RefPtr<TextEditRules> rules(mRules);

  // is doc empty?
  if (rules->DocumentIsEmpty()) {
    // get editor root node
    Element* rootElement = GetRoot();

    // if its empty dont select entire doc - that would select the bogus node
    return aSelection->Collapse(rootElement, 0);
  }

  return EditorBase::SelectEntireDocument(aSelection);
}

nsresult
HTMLEditor::SelectAllInternal()
{
  CommitComposition();
  if (NS_WARN_IF(Destroyed())) {
    return NS_ERROR_EDITOR_DESTROYED;
  }

  // XXX Perhaps, we should check whether we still have focus since composition
  //     event listener may have already moved focus to different editing
  //     host or other element.  So, perhaps, we need to retrieve anchor node
  //     before committing composition and check if selection is still in
  //     same editing host.

  RefPtr<Selection> selection = GetSelection();
  if (NS_WARN_IF(!selection)) {
    return NS_ERROR_FAILURE;
  }

  nsINode* anchorNode = selection->GetAnchorNode();
  if (NS_WARN_IF(!anchorNode) || NS_WARN_IF(!anchorNode->IsContent())) {
    return NS_ERROR_FAILURE;
  }

  nsIContent* anchorContent = anchorNode->AsContent();
  nsIContent* rootContent;
  if (anchorContent->HasIndependentSelection()) {
    selection->SetAncestorLimiter(nullptr);
    rootContent = mRootElement;
  } else {
    nsCOMPtr<nsIPresShell> ps = GetPresShell();
    rootContent = anchorContent->GetSelectionRootContent(ps);
  }

  if (NS_WARN_IF(!rootContent)) {
    return NS_ERROR_UNEXPECTED;
  }

  Maybe<mozilla::dom::Selection::AutoUserInitiated> userSelection;
  if (!rootContent->IsEditable()) {
    userSelection.emplace(selection);
  }
  ErrorResult errorResult;
  selection->SelectAllChildren(*rootContent, errorResult);
  NS_WARNING_ASSERTION(!errorResult.Failed(), "SelectAllChildren() failed");
  return errorResult.StealNSResult();
}

// this will NOT find aAttribute unless aAttribute has a non-null value
// so singleton attributes like <Table border> will not be matched!
bool
HTMLEditor::IsTextPropertySetByContent(nsINode* aNode,
                                       nsAtom* aProperty,
                                       nsAtom* aAttribute,
                                       const nsAString* aValue,
                                       nsAString* outValue)
{
  MOZ_ASSERT(aNode && aProperty);

  while (aNode) {
    if (aNode->IsElement()) {
      Element* element = aNode->AsElement();
      if (aProperty == element->NodeInfo()->NameAtom()) {
        if (!aAttribute) {
          return true;
        }
        nsAutoString value;
        element->GetAttr(kNameSpaceID_None, aAttribute, value);
        if (outValue) {
          *outValue = value;
        }
        if (!value.IsEmpty()) {
          if (!aValue) {
            return true;
          }
          if (aValue->Equals(value, nsCaseInsensitiveStringComparator())) {
            return true;
          }
          // We found the prop with the attribute, but the value doesn't
          // match.
          break;
        }
      }
    }
    aNode = aNode->GetParentNode();
  }
  return false;
}

bool
HTMLEditor::SetCaretInTableCell(Element* aElement)
{
  if (!aElement || !aElement->IsHTMLElement() ||
      !HTMLEditUtils::IsTableElement(aElement) ||
      !IsDescendantOfEditorRoot(aElement)) {
    return false;
  }

  nsIContent* node = aElement;
  while (node->HasChildren()) {
    node = node->GetFirstChild();
  }

  // Set selection at beginning of the found node
  RefPtr<Selection> selection = GetSelection();
  NS_ENSURE_TRUE(selection, false);

  return NS_SUCCEEDED(selection->Collapse(node, 0));
}

/**
 * GetEnclosingTable() finds ancestor who is a table, if any.
 */
Element*
HTMLEditor::GetEnclosingTable(nsINode* aNode)
{
  MOZ_ASSERT(aNode);

  for (nsCOMPtr<Element> block = GetBlockNodeParent(aNode);
       block;
       block = GetBlockNodeParent(block)) {
    if (HTMLEditUtils::IsTable(block)) {
      return block;
    }
  }
  return nullptr;
}

/**
 * This method scans the selection for adjacent text nodes
 * and collapses them into a single text node.
 * "adjacent" means literally adjacent siblings of the same parent.
 * Uses EditorBase::JoinNodesWithTransaction() so action is undoable.
 * Should be called within the context of a batch transaction.
 */
nsresult
HTMLEditor::CollapseAdjacentTextNodes(nsRange* aInRange)
{
  NS_ENSURE_TRUE(aInRange, NS_ERROR_NULL_POINTER);
  AutoTransactionsConserveSelection dontChangeMySelection(*this);
  nsTArray<nsCOMPtr<nsINode>> textNodes;
  // we can't actually do anything during iteration, so store the text nodes in an array
  // don't bother ref counting them because we know we can hold them for the
  // lifetime of this method


  // build a list of editable text nodes
  nsresult rv = NS_ERROR_UNEXPECTED;
  nsCOMPtr<nsIContentIterator> iter =
    do_CreateInstance("@mozilla.org/content/subtree-content-iterator;1", &rv);
  NS_ENSURE_SUCCESS(rv, rv);

  iter->Init(aInRange);

  while (!iter->IsDone()) {
    nsINode* node = iter->GetCurrentNode();
    if (node->NodeType() == nsINode::TEXT_NODE &&
        IsEditable(node->AsContent())) {
      textNodes.AppendElement(node);
    }

    iter->Next();
  }

  // now that I have a list of text nodes, collapse adjacent text nodes
  // NOTE: assumption that JoinNodes keeps the righthand node
  while (textNodes.Length() > 1) {
    // we assume a textNodes entry can't be nullptr
    nsINode* leftTextNode = textNodes[0];
    nsINode* rightTextNode = textNodes[1];
    NS_ASSERTION(leftTextNode && rightTextNode,"left or rightTextNode null in CollapseAdjacentTextNodes");

    // get the prev sibling of the right node, and see if its leftTextNode
    nsCOMPtr<nsINode> prevSibOfRightNode = rightTextNode->GetPreviousSibling();
    if (prevSibOfRightNode && prevSibOfRightNode == leftTextNode) {
      rv = JoinNodesWithTransaction(*leftTextNode, *rightTextNode);
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }
    }

    textNodes.RemoveElementAt(0); // remove the leftmost text node from the list
  }

  return NS_OK;
}

nsresult
HTMLEditor::SetSelectionAtDocumentStart(Selection* aSelection)
{
  dom::Element* rootElement = GetRoot();
  NS_ENSURE_TRUE(rootElement, NS_ERROR_NULL_POINTER);

  return aSelection->Collapse(rootElement, 0);
}

/**
 * Remove aNode, reparenting any children into the parent of aNode.  In
 * addition, insert any br's needed to preserve identity of removed block.
 */
nsresult
HTMLEditor::RemoveBlockContainerWithTransaction(Element& aElement)
{
  RefPtr<Selection> selection = GetSelection();
  if (NS_WARN_IF(!selection)) {
    return NS_ERROR_FAILURE;
  }

  // Two possibilities: the container could be empty of editable content.  If
  // that is the case, we need to compare what is before and after aNode to
  // determine if we need a br.
  //
  // Or it could be not empty, in which case we have to compare previous
  // sibling and first child to determine if we need a leading br, and compare
  // following sibling and last child to determine if we need a trailing br.

  nsCOMPtr<nsIContent> child = GetFirstEditableChild(aElement);

  if (child) {
    // The case of aNode not being empty.  We need a br at start unless:
    // 1) previous sibling of aNode is a block, OR
    // 2) previous sibling of aNode is a br, OR
    // 3) first child of aNode is a block OR
    // 4) either is null

    nsCOMPtr<nsIContent> sibling = GetPriorHTMLSibling(&aElement);
    if (sibling && !IsBlockNode(sibling) &&
        !sibling->IsHTMLElement(nsGkAtoms::br) && !IsBlockNode(child)) {
      // Insert br node
      RefPtr<Element> brElement =
        InsertBrElementWithTransaction(*selection,
                                       EditorRawDOMPoint(&aElement, 0));
      if (NS_WARN_IF(!brElement)) {
        return NS_ERROR_FAILURE;
      }
    }

    // We need a br at end unless:
    // 1) following sibling of aNode is a block, OR
    // 2) last child of aNode is a block, OR
    // 3) last child of aNode is a br OR
    // 4) either is null

    sibling = GetNextHTMLSibling(&aElement);
    if (sibling && !IsBlockNode(sibling)) {
      child = GetLastEditableChild(aElement);
      MOZ_ASSERT(child, "aNode has first editable child but not last?");
      if (!IsBlockNode(child) && !child->IsHTMLElement(nsGkAtoms::br)) {
        // Insert br node
        EditorRawDOMPoint endOfNode;
        endOfNode.SetToEndOf(&aElement);
        RefPtr<Element> brElement =
          InsertBrElementWithTransaction(*selection, endOfNode);
        if (NS_WARN_IF(!brElement)) {
          return NS_ERROR_FAILURE;
        }
      }
    }
  } else {
    // The case of aNode being empty.  We need a br at start unless:
    // 1) previous sibling of aNode is a block, OR
    // 2) previous sibling of aNode is a br, OR
    // 3) following sibling of aNode is a block, OR
    // 4) following sibling of aNode is a br OR
    // 5) either is null
    nsCOMPtr<nsIContent> sibling = GetPriorHTMLSibling(&aElement);
    if (sibling && !IsBlockNode(sibling) &&
        !sibling->IsHTMLElement(nsGkAtoms::br)) {
      sibling = GetNextHTMLSibling(&aElement);
      if (sibling && !IsBlockNode(sibling) &&
          !sibling->IsHTMLElement(nsGkAtoms::br)) {
        // Insert br node
        RefPtr<Element> brElement =
          InsertBrElementWithTransaction(*selection,
                                         EditorRawDOMPoint(&aElement, 0));
        if (NS_WARN_IF(!brElement)) {
          return NS_ERROR_FAILURE;
        }
      }
    }
  }

  // Now remove container
  nsresult rv = RemoveContainerWithTransaction(aElement);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }
  return NS_OK;
}

/**
 * GetPriorHTMLSibling() returns the previous editable sibling, if there is
 * one within the parent.
 */
nsIContent*
HTMLEditor::GetPriorHTMLSibling(nsINode* aNode)
{
  MOZ_ASSERT(aNode);

  nsIContent* node = aNode->GetPreviousSibling();
  while (node && !IsEditable(node)) {
    node = node->GetPreviousSibling();
  }

  return node;
}

/**
 * GetNextHTMLSibling() returns the next editable sibling, if there is
 * one within the parent.
 */
nsIContent*
HTMLEditor::GetNextHTMLSibling(nsINode* aNode)
{
  MOZ_ASSERT(aNode);

  nsIContent* node = aNode->GetNextSibling();
  while (node && !IsEditable(node)) {
    node = node->GetNextSibling();
  }

  return node;
}

nsIContent*
HTMLEditor::GetPreviousHTMLElementOrTextInternal(nsINode& aNode,
                                                 bool aNoBlockCrossing)
{
  if (!GetActiveEditingHost()) {
    return nullptr;
  }
  return aNoBlockCrossing ? GetPreviousElementOrTextInBlock(aNode) :
                            GetPreviousElementOrText(aNode);
}

template<typename PT, typename CT>
nsIContent*
HTMLEditor::GetPreviousHTMLElementOrTextInternal(
              const EditorDOMPointBase<PT, CT>& aPoint,
              bool aNoBlockCrossing)
{
  if (!GetActiveEditingHost()) {
    return nullptr;
  }
  return aNoBlockCrossing ? GetPreviousElementOrTextInBlock(aPoint) :
                            GetPreviousElementOrText(aPoint);
}

nsIContent*
HTMLEditor::GetPreviousEditableHTMLNodeInternal(nsINode& aNode,
                                                bool aNoBlockCrossing)
{
  if (!GetActiveEditingHost()) {
    return nullptr;
  }
  return aNoBlockCrossing ? GetPreviousEditableNodeInBlock(aNode) :
                            GetPreviousEditableNode(aNode);
}

template<typename PT, typename CT>
nsIContent*
HTMLEditor::GetPreviousEditableHTMLNodeInternal(
              const EditorDOMPointBase<PT, CT>& aPoint,
              bool aNoBlockCrossing)
{
  if (!GetActiveEditingHost()) {
    return nullptr;
  }
  return aNoBlockCrossing ? GetPreviousEditableNodeInBlock(aPoint) :
                            GetPreviousEditableNode(aPoint);
}

nsIContent*
HTMLEditor::GetNextHTMLElementOrTextInternal(nsINode& aNode,
                                             bool aNoBlockCrossing)
{
  if (!GetActiveEditingHost()) {
    return nullptr;
  }
  return aNoBlockCrossing ? GetNextElementOrTextInBlock(aNode) :
                            GetNextElementOrText(aNode);
}

template<typename PT, typename CT>
nsIContent*
HTMLEditor::GetNextHTMLElementOrTextInternal(
              const EditorDOMPointBase<PT, CT>& aPoint,
              bool aNoBlockCrossing)
{
  if (!GetActiveEditingHost()) {
    return nullptr;
  }
  return aNoBlockCrossing ? GetNextElementOrTextInBlock(aPoint) :
                            GetNextElementOrText(aPoint);
}

nsIContent*
HTMLEditor::GetNextEditableHTMLNodeInternal(nsINode& aNode,
                                            bool aNoBlockCrossing)
{
  if (!GetActiveEditingHost()) {
    return nullptr;
  }
  return aNoBlockCrossing ? GetNextEditableNodeInBlock(aNode) :
                            GetNextEditableNode(aNode);
}

template<typename PT, typename CT>
nsIContent*
HTMLEditor::GetNextEditableHTMLNodeInternal(
              const EditorDOMPointBase<PT, CT>& aPoint,
              bool aNoBlockCrossing)
{
  if (!GetActiveEditingHost()) {
    return nullptr;
  }
  return aNoBlockCrossing ? GetNextEditableNodeInBlock(aPoint) :
                            GetNextEditableNode(aPoint);
}

bool
HTMLEditor::IsFirstEditableChild(nsINode* aNode)
{
  MOZ_ASSERT(aNode);
  // find first editable child and compare it to aNode
  nsCOMPtr<nsINode> parent = aNode->GetParentNode();
  if (NS_WARN_IF(!parent)) {
    return false;
  }
  return (GetFirstEditableChild(*parent) == aNode);
}

bool
HTMLEditor::IsLastEditableChild(nsINode* aNode)
{
  MOZ_ASSERT(aNode);
  // find last editable child and compare it to aNode
  nsCOMPtr<nsINode> parent = aNode->GetParentNode();
  if (NS_WARN_IF(!parent)) {
    return false;
  }
  return (GetLastEditableChild(*parent) == aNode);
}

nsIContent*
HTMLEditor::GetFirstEditableChild(nsINode& aNode)
{
  nsCOMPtr<nsIContent> child = aNode.GetFirstChild();

  while (child && !IsEditable(child)) {
    child = child->GetNextSibling();
  }

  return child;
}

nsIContent*
HTMLEditor::GetLastEditableChild(nsINode& aNode)
{
  nsCOMPtr<nsIContent> child = aNode.GetLastChild();

  while (child && !IsEditable(child)) {
    child = child->GetPreviousSibling();
  }

  return child;
}

nsIContent*
HTMLEditor::GetFirstEditableLeaf(nsINode& aNode)
{
  nsCOMPtr<nsIContent> child = GetLeftmostChild(&aNode);
  while (child && (!IsEditable(child) || child->HasChildren())) {
    child = GetNextEditableHTMLNode(*child);

    // Only accept nodes that are descendants of aNode
    if (!aNode.Contains(child)) {
      return nullptr;
    }
  }

  return child;
}

nsIContent*
HTMLEditor::GetLastEditableLeaf(nsINode& aNode)
{
  nsCOMPtr<nsIContent> child = GetRightmostChild(&aNode, false);
  while (child && (!IsEditable(child) || child->HasChildren())) {
    child = GetPreviousEditableHTMLNode(*child);

    // Only accept nodes that are descendants of aNode
    if (!aNode.Contains(child)) {
      return nullptr;
    }
  }

  return child;
}

bool
HTMLEditor::IsInVisibleTextFrames(Text& aText)
{
  nsISelectionController* selectionController = GetSelectionController();
  if (NS_WARN_IF(!selectionController)) {
    return false;
  }

  if (!aText.TextDataLength()) {
    return false;
  }

  // Ask the selection controller for information about whether any of the
  // data in the node is really rendered.  This is really something that
  // frames know about, but we aren't supposed to talk to frames.  So we put
  // a call in the selection controller interface, since it's already in bed
  // with frames anyway.  (This is a fix for bug 22227, and a partial fix for
  // bug 46209.)
  bool isVisible = false;
  nsresult rv =
    selectionController->CheckVisibilityContent(&aText,
                                                0, aText.TextDataLength(),
                                                &isVisible);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return false;
  }
  return isVisible;
}

bool
HTMLEditor::IsVisibleTextNode(Text& aText)
{
  if (!aText.TextDataLength()) {
    return false;
  }

  if (!aText.TextIsOnlyWhitespace()) {
    return true;
  }

  WSRunObject wsRunObj(this, &aText, 0);
  nsCOMPtr<nsINode> nextVisibleNode;
  int32_t unused = 0;
  WSType visibleNodeType;
  wsRunObj.NextVisibleNode(EditorRawDOMPoint(&aText, 0),
                           address_of(nextVisibleNode),
                           &unused, &visibleNodeType);
  return (visibleNodeType == WSType::normalWS ||
          visibleNodeType == WSType::text) &&
         &aText == nextVisibleNode;
}

/**
 * IsEmptyNode() figures out if aNode is an empty node.  A block can have
 * children and still be considered empty, if the children are empty or
 * non-editable.
 */
nsresult
HTMLEditor::IsEmptyNode(nsINode* aNode,
                        bool* outIsEmptyNode,
                        bool aSingleBRDoesntCount,
                        bool aListOrCellNotEmpty,
                        bool aSafeToAskFrames)
{
  NS_ENSURE_TRUE(aNode && outIsEmptyNode, NS_ERROR_NULL_POINTER);
  *outIsEmptyNode = true;
  bool seenBR = false;
  return IsEmptyNodeImpl(aNode, outIsEmptyNode, aSingleBRDoesntCount,
                         aListOrCellNotEmpty, aSafeToAskFrames, &seenBR);
}

/**
 * IsEmptyNodeImpl() is workhorse for IsEmptyNode().
 */
nsresult
HTMLEditor::IsEmptyNodeImpl(nsINode* aNode,
                            bool* outIsEmptyNode,
                            bool aSingleBRDoesntCount,
                            bool aListOrCellNotEmpty,
                            bool aSafeToAskFrames,
                            bool* aSeenBR)
{
  NS_ENSURE_TRUE(aNode && outIsEmptyNode && aSeenBR, NS_ERROR_NULL_POINTER);

  if (Text* text = aNode->GetAsText()) {
    *outIsEmptyNode = aSafeToAskFrames ? !IsInVisibleTextFrames(*text) :
                                         !IsVisibleTextNode(*text);
    return NS_OK;
  }

  // if it's not a text node (handled above) and it's not a container,
  // then we don't call it empty (it's an <hr>, or <br>, etc.).
  // Also, if it's an anchor then don't treat it as empty - even though
  // anchors are containers, named anchors are "empty" but we don't
  // want to treat them as such.  Also, don't call ListItems or table
  // cells empty if caller desires.  Form Widgets not empty.
  if (!IsContainer(aNode) ||
      (HTMLEditUtils::IsNamedAnchor(aNode) ||
       HTMLEditUtils::IsFormWidget(aNode) ||
       (aListOrCellNotEmpty &&
        (HTMLEditUtils::IsListItem(aNode) ||
         HTMLEditUtils::IsTableCell(aNode))))) {
    *outIsEmptyNode = false;
    return NS_OK;
  }

  // need this for later
  bool isListItemOrCell = HTMLEditUtils::IsListItem(aNode) ||
                          HTMLEditUtils::IsTableCell(aNode);

  // loop over children of node. if no children, or all children are either
  // empty text nodes or non-editable, then node qualifies as empty
  for (nsCOMPtr<nsIContent> child = aNode->GetFirstChild();
       child;
       child = child->GetNextSibling()) {
    // Is the child editable and non-empty?  if so, return false
    if (EditorBase::IsEditable(child)) {
      if (Text* text = child->GetAsText()) {
        // break out if we find we aren't empty
        *outIsEmptyNode = aSafeToAskFrames ? !IsInVisibleTextFrames(*text) :
                                             !IsVisibleTextNode(*text);
        if (!*outIsEmptyNode){
          return NS_OK;
        }
      } else {
        // An editable, non-text node. We need to check its content.
        // Is it the node we are iterating over?
        if (child == aNode) {
          break;
        }

        if (aSingleBRDoesntCount && !*aSeenBR && child->IsHTMLElement(nsGkAtoms::br)) {
          // the first br in a block doesn't count if the caller so indicated
          *aSeenBR = true;
        } else {
          // is it an empty node of some sort?
          // note: list items or table cells are not considered empty
          // if they contain other lists or tables
          if (child->IsElement()) {
            if (isListItemOrCell) {
              if (HTMLEditUtils::IsList(child) ||
                  child->IsHTMLElement(nsGkAtoms::table)) {
                // break out if we find we aren't empty
                *outIsEmptyNode = false;
                return NS_OK;
              }
            } else if (HTMLEditUtils::IsFormWidget(child)) {
              // is it a form widget?
              // break out if we find we aren't empty
              *outIsEmptyNode = false;
              return NS_OK;
            }
          }

          bool isEmptyNode = true;
          nsresult rv = IsEmptyNodeImpl(child, &isEmptyNode,
                                        aSingleBRDoesntCount,
                                        aListOrCellNotEmpty, aSafeToAskFrames,
                                        aSeenBR);
          NS_ENSURE_SUCCESS(rv, rv);
          if (!isEmptyNode) {
            // otherwise it ain't empty
            *outIsEmptyNode = false;
            return NS_OK;
          }
        }
      }
    }
  }

  return NS_OK;
}

// add to aElement the CSS inline styles corresponding to the HTML attribute
// aAttribute with its value aValue
nsresult
HTMLEditor::SetAttributeOrEquivalent(Element* aElement,
                                     nsAtom* aAttribute,
                                     const nsAString& aValue,
                                     bool aSuppressTransaction)
{
  MOZ_ASSERT(aElement);
  MOZ_ASSERT(aAttribute);

  nsAutoScriptBlocker scriptBlocker;

  if (!IsCSSEnabled() || !mCSSEditUtils) {
    // we are not in an HTML+CSS editor; let's set the attribute the HTML way
    if (mCSSEditUtils) {
      mCSSEditUtils->RemoveCSSEquivalentToHTMLStyle(aElement, nullptr,
                                                    aAttribute, nullptr,
                                                    aSuppressTransaction);
    }
    return aSuppressTransaction ?
             aElement->SetAttr(kNameSpaceID_None, aAttribute, aValue, true) :
             SetAttributeWithTransaction(*aElement, *aAttribute, aValue);
  }

  int32_t count =
    mCSSEditUtils->SetCSSEquivalentToHTMLStyle(aElement, nullptr,
                                               aAttribute, &aValue,
                                               aSuppressTransaction);
  if (count) {
    // we found an equivalence ; let's remove the HTML attribute itself if it
    // is set
    nsAutoString existingValue;
    if (!aElement->GetAttr(kNameSpaceID_None, aAttribute, existingValue)) {
      return NS_OK;
    }

    return aSuppressTransaction ?
             aElement->UnsetAttr(kNameSpaceID_None, aAttribute, true) :
             RemoveAttributeWithTransaction(*aElement, *aAttribute);
  }

  // count is an integer that represents the number of CSS declarations applied
  // to the element. If it is zero, we found no equivalence in this
  // implementation for the attribute
  if (aAttribute == nsGkAtoms::style) {
    // if it is the style attribute, just add the new value to the existing
    // style attribute's value
    nsAutoString existingValue;
    aElement->GetAttr(kNameSpaceID_None, nsGkAtoms::style, existingValue);
    existingValue.Append(' ');
    existingValue.Append(aValue);
    return aSuppressTransaction ?
       aElement->SetAttr(kNameSpaceID_None, aAttribute, existingValue, true) :
      SetAttributeWithTransaction(*aElement, *aAttribute, existingValue);
  }

  // we have no CSS equivalence for this attribute and it is not the style
  // attribute; let's set it the good'n'old HTML way
  return aSuppressTransaction ?
           aElement->SetAttr(kNameSpaceID_None, aAttribute, aValue, true) :
           SetAttributeWithTransaction(*aElement, *aAttribute, aValue);
}

nsresult
HTMLEditor::RemoveAttributeOrEquivalent(Element* aElement,
                                        nsAtom* aAttribute,
                                        bool aSuppressTransaction)
{
  MOZ_ASSERT(aElement);
  MOZ_ASSERT(aAttribute);

  if (IsCSSEnabled() && mCSSEditUtils) {
    nsresult rv =
      mCSSEditUtils->RemoveCSSEquivalentToHTMLStyle(
        aElement, nullptr, aAttribute, nullptr, aSuppressTransaction);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  if (!aElement->HasAttr(kNameSpaceID_None, aAttribute)) {
    return NS_OK;
  }

  return aSuppressTransaction ?
    aElement->UnsetAttr(kNameSpaceID_None, aAttribute, /* aNotify = */ true) :
    RemoveAttributeWithTransaction(*aElement, *aAttribute);
}

nsresult
HTMLEditor::SetIsCSSEnabled(bool aIsCSSPrefChecked)
{
  if (!mCSSEditUtils) {
    return NS_ERROR_NOT_INITIALIZED;
  }

  mCSSEditUtils->SetCSSEnabled(aIsCSSPrefChecked);

  // Disable the eEditorNoCSSMask flag if we're enabling StyleWithCSS.
  uint32_t flags = mFlags;
  if (aIsCSSPrefChecked) {
    // Turn off NoCSS as we're enabling CSS
    flags &= ~eEditorNoCSSMask;
  } else {
    // Turn on NoCSS, as we're disabling CSS.
    flags |= eEditorNoCSSMask;
  }

  return SetFlags(flags);
}

// Set the block background color
nsresult
HTMLEditor::SetCSSBackgroundColorWithTransaction(const nsAString& aColor)
{
  NS_ENSURE_TRUE(mRules, NS_ERROR_NOT_INITIALIZED);
  CommitComposition();

  // Protect the edit rules object from dying
  RefPtr<TextEditRules> rules(mRules);

  RefPtr<Selection> selection = GetSelection();
  NS_ENSURE_STATE(selection);

  bool isCollapsed = selection->IsCollapsed();

  AutoPlaceholderBatch batchIt(this);
  AutoTopLevelEditSubActionNotifier maybeTopLevelEditSubAction(
                                      *this, EditSubAction::eInsertElement,
                                      nsIEditor::eNext);
  AutoSelectionRestorer selectionRestorer(selection, this);
  AutoTransactionsConserveSelection dontChangeMySelection(*this);

  // XXX Although, this method may set background color of ancestor block
  //     element, using EditSubAction::eSetTextProperty.
  bool cancel, handled;
  EditSubActionInfo subActionInfo(EditSubAction::eSetTextProperty);
  nsresult rv =
    rules->WillDoAction(selection, subActionInfo, &cancel, &handled);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }
  if (!cancel && !handled) {
    // Loop through the ranges in the selection
    for (uint32_t i = 0; i < selection->RangeCount(); i++) {
      RefPtr<nsRange> range = selection->GetRangeAt(i);
      NS_ENSURE_TRUE(range, NS_ERROR_FAILURE);

      nsCOMPtr<Element> cachedBlockParent;

      // Check for easy case: both range endpoints in same text node
      nsCOMPtr<nsINode> startNode = range->GetStartContainer();
      int32_t startOffset = range->StartOffset();
      nsCOMPtr<nsINode> endNode = range->GetEndContainer();
      int32_t endOffset = range->EndOffset();
      if (startNode == endNode && IsTextNode(startNode)) {
        // Let's find the block container of the text node
        nsCOMPtr<Element> blockParent = GetBlockNodeParent(startNode);
        // And apply the background color to that block container
        if (blockParent && cachedBlockParent != blockParent) {
          cachedBlockParent = blockParent;
          mCSSEditUtils->SetCSSEquivalentToHTMLStyle(blockParent, nullptr,
                                                     nsGkAtoms::bgcolor,
                                                     &aColor, false);
        }
      } else if (startNode == endNode &&
                 startNode->IsHTMLElement(nsGkAtoms::body) && isCollapsed) {
        // No block in the document, let's apply the background to the body
        mCSSEditUtils->SetCSSEquivalentToHTMLStyle(startNode->AsElement(),
                                                   nullptr, nsGkAtoms::bgcolor,
                                                   &aColor,
                                                   false);
      } else if (startNode == endNode && (endOffset - startOffset == 1 ||
                                          (!startOffset && !endOffset))) {
        // A unique node is selected, let's also apply the background color to
        // the containing block, possibly the node itself
        nsCOMPtr<nsIContent> selectedNode = range->GetChildAtStartOffset();
        nsCOMPtr<Element> blockParent = GetBlock(*selectedNode);
        if (blockParent && cachedBlockParent != blockParent) {
          cachedBlockParent = blockParent;
          mCSSEditUtils->SetCSSEquivalentToHTMLStyle(blockParent, nullptr,
                                                     nsGkAtoms::bgcolor,
                                                     &aColor, false);
        }
      } else {
        // Not the easy case.  Range not contained in single text node.  There
        // are up to three phases here.  There are all the nodes reported by
        // the subtree iterator to be processed.  And there are potentially a
        // starting textnode and an ending textnode which are only partially
        // contained by the range.

        // Let's handle the nodes reported by the iterator.  These nodes are
        // entirely contained in the selection range.  We build up a list of
        // them (since doing operations on the document during iteration would
        // perturb the iterator).

        OwningNonNull<nsIContentIterator> iter =
          NS_NewContentSubtreeIterator();

        nsTArray<OwningNonNull<nsINode>> arrayOfNodes;
        nsCOMPtr<nsINode> node;

        // Iterate range and build up array
        rv = iter->Init(range);
        // Init returns an error if no nodes in range.  This can easily happen
        // with the subtree iterator if the selection doesn't contain any
        // *whole* nodes.
        if (NS_SUCCEEDED(rv)) {
          for (; !iter->IsDone(); iter->Next()) {
            node = do_QueryInterface(iter->GetCurrentNode());
            NS_ENSURE_TRUE(node, NS_ERROR_FAILURE);

            if (IsEditable(node)) {
              arrayOfNodes.AppendElement(*node);
            }
          }
        }
        // First check the start parent of the range to see if it needs to be
        // separately handled (it does if it's a text node, due to how the
        // subtree iterator works - it will not have reported it).
        if (IsTextNode(startNode) && IsEditable(startNode)) {
          nsCOMPtr<Element> blockParent = GetBlockNodeParent(startNode);
          if (blockParent && cachedBlockParent != blockParent) {
            cachedBlockParent = blockParent;
            mCSSEditUtils->SetCSSEquivalentToHTMLStyle(blockParent, nullptr,
                                                       nsGkAtoms::bgcolor,
                                                       &aColor,
                                                       false);
          }
        }

        // Then loop through the list, set the property on each node
        for (auto& node : arrayOfNodes) {
          nsCOMPtr<Element> blockParent = GetBlock(node);
          if (blockParent && cachedBlockParent != blockParent) {
            cachedBlockParent = blockParent;
            mCSSEditUtils->SetCSSEquivalentToHTMLStyle(blockParent, nullptr,
                                                       nsGkAtoms::bgcolor,
                                                       &aColor,
                                                       false);
          }
        }
        arrayOfNodes.Clear();

        // Last, check the end parent of the range to see if it needs to be
        // separately handled (it does if it's a text node, due to how the
        // subtree iterator works - it will not have reported it).
        if (IsTextNode(endNode) && IsEditable(endNode)) {
          nsCOMPtr<Element> blockParent = GetBlockNodeParent(endNode);
          if (blockParent && cachedBlockParent != blockParent) {
            cachedBlockParent = blockParent;
            mCSSEditUtils->SetCSSEquivalentToHTMLStyle(blockParent, nullptr,
                                                       nsGkAtoms::bgcolor,
                                                       &aColor,
                                                       false);
          }
        }
      }
    }
  }
  if (!cancel) {
    // Post-process
    rv = rules->DidDoAction(selection, subActionInfo, rv);
    NS_ENSURE_SUCCESS(rv, rv);
  }
  return NS_OK;
}

NS_IMETHODIMP
HTMLEditor::SetBackgroundColor(const nsAString& aColor)
{
  if (IsCSSEnabled()) {
    // if we are in CSS mode, we have to apply the background color to the
    // containing block (or the body if we have no block-level element in
    // the document)
    return SetCSSBackgroundColorWithTransaction(aColor);
  }

  // but in HTML mode, we can only set the document's background color
  return SetHTMLBackgroundColorWithTransaction(aColor);
}

/**
 * NodesSameType() does these nodes have the same tag?
 */
bool
HTMLEditor::AreNodesSameType(nsIContent* aNode1,
                             nsIContent* aNode2)
{
  MOZ_ASSERT(aNode1);
  MOZ_ASSERT(aNode2);

  if (aNode1->NodeInfo()->NameAtom() != aNode2->NodeInfo()->NameAtom()) {
    return false;
  }

  if (!IsCSSEnabled() || !aNode1->IsHTMLElement(nsGkAtoms::span)) {
    return true;
  }

  if (!aNode1->IsElement() || !aNode2->IsElement()) {
    return false;
  }

  // If CSS is enabled, we are stricter about span nodes.
  return CSSEditUtils::ElementsSameStyle(aNode1->AsElement(),
                                         aNode2->AsElement());
}

nsresult
HTMLEditor::CopyLastEditableChildStylesWithTransaction(
              Element& aPreviousBlock,
              Element& aNewBlock,
              RefPtr<Element>* aNewBrElement)
{
  if (NS_WARN_IF(!aNewBrElement)) {
    return NS_ERROR_INVALID_ARG;
  }
  *aNewBrElement = nullptr;

  RefPtr<Element> previousBlock(&aPreviousBlock);
  RefPtr<Element> newBlock(&aNewBlock);

  // First, clear out aNewBlock.  Contract is that we want only the styles
  // from aPreviousBlock.
  for (nsCOMPtr<nsINode> child = newBlock->GetFirstChild();
       child;
       child = newBlock->GetFirstChild()) {
    nsresult rv = DeleteNodeWithTransaction(*child);
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }
  }

  // XXX aNewBlock may be moved or removed.  Even in such case, we should
  //     keep cloning the styles?

  // Look for the deepest last editable leaf node in aPreviousBlock.
  // Then, if found one is a <br> element, look for non-<br> element.
  nsIContent* deepestEditableContent = nullptr;
  for (nsCOMPtr<nsIContent> child = previousBlock.get();
       child;
       child = GetLastEditableChild(*child)) {
    deepestEditableContent = child;
  }
  while (deepestEditableContent &&
         TextEditUtils::IsBreak(deepestEditableContent)) {
    deepestEditableContent =
      GetPreviousEditableHTMLNode(*deepestEditableContent);
  }
  Element* deepestVisibleEditableElement = nullptr;
  if (deepestEditableContent) {
    deepestVisibleEditableElement =
      deepestEditableContent->IsElement() ?
        deepestEditableContent->AsElement() :
        deepestEditableContent->GetParentElement();
  }

  // Clone inline elements to keep current style in the new block.
  // XXX Looks like that this is really slow if lastEditableDescendant is
  //     far from aPreviousBlock.  Probably, we should clone inline containers
  //     from ancestor to descendants without transactions, then, insert it
  //     after that with transaction.
  RefPtr<Element> lastClonedElement, firstClonsedElement;
  for (RefPtr<Element> elementInPreviousBlock = deepestVisibleEditableElement;
       elementInPreviousBlock && elementInPreviousBlock != previousBlock;
       elementInPreviousBlock = elementInPreviousBlock->GetParentElement()) {
    if (!HTMLEditUtils::IsInlineStyle(elementInPreviousBlock) &&
        !elementInPreviousBlock->IsHTMLElement(nsGkAtoms::span)) {
      continue;
    }
    nsAtom* tagName = elementInPreviousBlock->NodeInfo()->NameAtom();
    // At first time, just create the most descendant inline container element.
    if (!firstClonsedElement) {
      EditorRawDOMPoint atStartOfNewBlock(newBlock, 0);
      firstClonsedElement = lastClonedElement =
        CreateNodeWithTransaction(*tagName, atStartOfNewBlock);
      if (NS_WARN_IF(!firstClonsedElement)) {
        return NS_ERROR_FAILURE;
      }
      // Clone all attributes.
      // XXX Looks like that this clones id attribute too.
      CloneAttributesWithTransaction(*lastClonedElement,
                                     *elementInPreviousBlock);
      continue;
    }
    // Otherwise, inserts new parent inline container to the previous inserted
    // inline container.
    lastClonedElement =
      InsertContainerWithTransaction(*lastClonedElement, *tagName);
    if (NS_WARN_IF(!lastClonedElement)) {
      return NS_ERROR_FAILURE;
    }
    CloneAttributesWithTransaction(*lastClonedElement, *elementInPreviousBlock);
  }

  if (!firstClonsedElement) {
    // XXX Even if no inline elements are cloned, shouldn't we create new
    //     <br> element for aNewBlock?
    return NS_OK;
  }

  RefPtr<Selection> selection = GetSelection();
  if (NS_WARN_IF(!selection)) {
    return NS_ERROR_FAILURE;
  }
  RefPtr<Element> brElement =
    InsertBrElementWithTransaction(*selection,
                                   EditorRawDOMPoint(firstClonsedElement, 0));
  if (NS_WARN_IF(!brElement)) {
    return NS_ERROR_FAILURE;
  }
  *aNewBrElement = brElement.forget();
  return NS_OK;
}

nsresult
HTMLEditor::GetElementOrigin(Element& aElement,
                             int32_t& aX,
                             int32_t& aY)
{
  aX = 0;
  aY = 0;

  if (NS_WARN_IF(!IsInitialized())) {
    return NS_ERROR_NOT_INITIALIZED;
  }
  nsCOMPtr<nsIPresShell> ps = GetPresShell();
  NS_ENSURE_TRUE(ps, NS_ERROR_NOT_INITIALIZED);

  nsIFrame* frame = aElement.GetPrimaryFrame();
  NS_ENSURE_TRUE(frame, NS_OK);

  nsIFrame *container = ps->GetAbsoluteContainingBlock(frame);
  NS_ENSURE_TRUE(container, NS_OK);
  nsPoint off = frame->GetOffsetTo(container);
  aX = nsPresContext::AppUnitsToIntCSSPixels(off.x);
  aY = nsPresContext::AppUnitsToIntCSSPixels(off.y);

  return NS_OK;
}

Element*
HTMLEditor::GetSelectionContainer()
{
  // If we don't get the selection, just skip this
  NS_ENSURE_TRUE(GetSelection(), nullptr);

  OwningNonNull<Selection> selection = *GetSelection();

  nsCOMPtr<nsINode> focusNode;

  if (selection->IsCollapsed()) {
    focusNode = selection->GetFocusNode();
  } else {
    int32_t rangeCount = selection->RangeCount();

    if (rangeCount == 1) {
      RefPtr<nsRange> range = selection->GetRangeAt(0);

      nsCOMPtr<nsINode> startContainer = range->GetStartContainer();
      int32_t startOffset = range->StartOffset();
      nsCOMPtr<nsINode> endContainer = range->GetEndContainer();
      int32_t endOffset = range->EndOffset();

      if (startContainer == endContainer && startOffset + 1 == endOffset) {
        MOZ_ASSERT(!focusNode, "How did it get set already?");
        focusNode = GetSelectedElement(EmptyString());
      }
      if (!focusNode) {
        focusNode = range->GetCommonAncestor();
      }
    } else {
      for (int32_t i = 0; i < rangeCount; i++) {
        RefPtr<nsRange> range = selection->GetRangeAt(i);

        nsCOMPtr<nsINode> startContainer = range->GetStartContainer();
        if (!focusNode) {
          focusNode = startContainer;
        } else if (focusNode != startContainer) {
          focusNode = startContainer->GetParentNode();
          break;
        }
      }
    }
  }

  if (focusNode && focusNode->GetAsText()) {
    focusNode = focusNode->GetParentNode();
  }

  if (focusNode && focusNode->IsElement()) {
    return focusNode->AsElement();
  }

  return nullptr;
}

NS_IMETHODIMP
HTMLEditor::IsAnonymousElement(Element* aElement,
                               bool* aReturn)
{
  NS_ENSURE_TRUE(aElement, NS_ERROR_NULL_POINTER);
  *aReturn = aElement->IsRootOfNativeAnonymousSubtree();
  return NS_OK;
}

nsresult
HTMLEditor::SetReturnInParagraphCreatesNewParagraph(bool aCreatesNewParagraph)
{
  mCRInParagraphCreatesParagraph = aCreatesNewParagraph;
  return NS_OK;
}

bool
HTMLEditor::GetReturnInParagraphCreatesNewParagraph()
{
  return mCRInParagraphCreatesParagraph;
}

nsresult
HTMLEditor::GetReturnInParagraphCreatesNewParagraph(bool* aCreatesNewParagraph)
{
  *aCreatesNewParagraph = mCRInParagraphCreatesParagraph;
  return NS_OK;
}

nsIContent*
HTMLEditor::GetFocusedContent()
{
  nsFocusManager* fm = nsFocusManager::GetFocusManager();
  NS_ENSURE_TRUE(fm, nullptr);

  nsCOMPtr<nsIContent> focusedContent = fm->GetFocusedElement();

  nsCOMPtr<nsIDocument> document = GetDocument();
  if (NS_WARN_IF(!document)) {
    return nullptr;
  }
  bool inDesignMode = document->HasFlag(NODE_IS_EDITABLE);
  if (!focusedContent) {
    // in designMode, nobody gets focus in most cases.
    if (inDesignMode && OurWindowHasFocus()) {
      return document->GetRootElement();
    }
    return nullptr;
  }

  if (inDesignMode) {
    return OurWindowHasFocus() &&
      nsContentUtils::ContentIsDescendantOf(focusedContent, document) ?
        focusedContent.get() : nullptr;
  }

  // We're HTML editor for contenteditable

  // If the focused content isn't editable, or it has independent selection,
  // we don't have focus.
  if (!focusedContent->HasFlag(NODE_IS_EDITABLE) ||
      focusedContent->HasIndependentSelection()) {
    return nullptr;
  }
  // If our window is focused, we're focused.
  return OurWindowHasFocus() ? focusedContent.get() : nullptr;
}

already_AddRefed<nsIContent>
HTMLEditor::GetFocusedContentForIME()
{
  nsCOMPtr<nsIContent> focusedContent = GetFocusedContent();
  if (!focusedContent) {
    return nullptr;
  }

  nsCOMPtr<nsIDocument> document = GetDocument();
  if (NS_WARN_IF(!document)) {
    return nullptr;
  }
  return document->HasFlag(NODE_IS_EDITABLE) ? nullptr :
                                               focusedContent.forget();
}

bool
HTMLEditor::IsActiveInDOMWindow()
{
  nsFocusManager* fm = nsFocusManager::GetFocusManager();
  NS_ENSURE_TRUE(fm, false);

  nsCOMPtr<nsIDocument> document = GetDocument();
  if (NS_WARN_IF(!document)) {
    return false;
  }
  bool inDesignMode = document->HasFlag(NODE_IS_EDITABLE);

  // If we're in designMode, we're always active in the DOM window.
  if (inDesignMode) {
    return true;
  }

  nsPIDOMWindowOuter* ourWindow = document->GetWindow();
  nsCOMPtr<nsPIDOMWindowOuter> win;
  nsIContent* content =
    nsFocusManager::GetFocusedDescendant(ourWindow,
                                         nsFocusManager::eOnlyCurrentWindow,
                                         getter_AddRefs(win));
  if (!content) {
    return false;
  }

  // We're HTML editor for contenteditable

  // If the active content isn't editable, or it has independent selection,
  // we're not active).
  if (!content->HasFlag(NODE_IS_EDITABLE) ||
      content->HasIndependentSelection()) {
    return false;
  }
  return true;
}

Element*
HTMLEditor::GetActiveEditingHost() const
{
  nsIDocument* document = GetDocument();
  if (NS_WARN_IF(!document)) {
    return nullptr;
  }
  if (document->HasFlag(NODE_IS_EDITABLE)) {
    return document->GetBodyElement();
  }

  // We're HTML editor for contenteditable
  Selection* selection = GetSelection();
  if (NS_WARN_IF(!selection)) {
    return nullptr;
  }
  nsINode* focusNode = selection->GetFocusNode();
  if (NS_WARN_IF(!focusNode) || NS_WARN_IF(!focusNode->IsContent())) {
    return nullptr;
  }
  nsIContent* content = focusNode->AsContent();

  // If the active content isn't editable, or it has independent selection,
  // we're not active.
  if (!content->HasFlag(NODE_IS_EDITABLE) ||
      content->HasIndependentSelection()) {
    return nullptr;
  }
  return content->GetEditingHost();
}

EventTarget*
HTMLEditor::GetDOMEventTarget()
{
  // Don't use getDocument here, because we have no way of knowing
  // whether Init() was ever called.  So we need to get the document
  // ourselves, if it exists.
  MOZ_ASSERT(IsInitialized(), "The HTMLEditor has not been initialized yet");
  nsCOMPtr<mozilla::dom::EventTarget> target = GetDocument();
  return target;
}

bool
HTMLEditor::ShouldReplaceRootElement()
{
  if (!mRootElement) {
    // If we don't know what is our root element, we should find our root.
    return true;
  }

  // If we temporary set document root element to mRootElement, but there is
  // body element now, we should replace the root element by the body element.
  return mRootElement != GetBodyElement();
}

void
HTMLEditor::NotifyRootChanged()
{
  nsCOMPtr<nsIMutationObserver> kungFuDeathGrip(this);

  RemoveEventListeners();
  nsresult rv = InstallEventListeners();
  if (NS_FAILED(rv)) {
    return;
  }

  UpdateRootElement();
  if (!mRootElement) {
    return;
  }

  rv = MaybeCollapseSelectionAtFirstEditableNode(false);
  if (NS_FAILED(rv)) {
    return;
  }

  // When this editor has focus, we need to reset the selection limiter to
  // new root.  Otherwise, that is going to be done when this gets focus.
  nsCOMPtr<nsINode> node = GetFocusedNode();
  if (node) {
    InitializeSelection(node);
  }

  SyncRealTimeSpell();
}

Element*
HTMLEditor::GetBodyElement()
{
  MOZ_ASSERT(IsInitialized(), "The HTMLEditor hasn't been initialized yet");
  nsCOMPtr<nsIDocument> document = GetDocument();
  if (NS_WARN_IF(!document)) {
    return nullptr;
  }
  return document->GetBody();
}

already_AddRefed<nsINode>
HTMLEditor::GetFocusedNode()
{
  nsCOMPtr<nsIContent> focusedContent = GetFocusedContent();
  if (!focusedContent) {
    return nullptr;
  }

  // focusedContent might be non-null even fm->GetFocusedContent() is
  // null.  That's the designMode case, and in that case our
  // FocusedContent() returns the root element, but we want to return
  // the document.

  nsFocusManager* fm = nsFocusManager::GetFocusManager();
  NS_ASSERTION(fm, "Focus manager is null");
  RefPtr<Element> focusedElement = fm->GetFocusedElement();
  if (focusedElement) {
    return focusedElement.forget();
  }

  nsCOMPtr<nsIDocument> document = GetDocument();
  return document.forget();
}

bool
HTMLEditor::OurWindowHasFocus()
{
  nsIFocusManager* fm = nsFocusManager::GetFocusManager();
  NS_ENSURE_TRUE(fm, false);
  nsCOMPtr<mozIDOMWindowProxy> focusedWindow;
  fm->GetFocusedWindow(getter_AddRefs(focusedWindow));
  if (!focusedWindow) {
    return false;
  }
  nsCOMPtr<nsIDocument> document = GetDocument();
  if (NS_WARN_IF(!document)) {
    return false;
  }
  nsPIDOMWindowOuter* ourWindow = document->GetWindow();
  return ourWindow == focusedWindow;
}

bool
HTMLEditor::IsAcceptableInputEvent(WidgetGUIEvent* aGUIEvent)
{
  if (!EditorBase::IsAcceptableInputEvent(aGUIEvent)) {
    return false;
  }

  // While there is composition, all composition events in its top level window
  // are always fired on the composing editor.  Therefore, if this editor has
  // composition, the composition events should be handled in this editor.
  if (mComposition && aGUIEvent->AsCompositionEvent()) {
    return true;
  }

  RefPtr<EventTarget> target = aGUIEvent->GetOriginalDOMEventTarget();
  nsCOMPtr<nsIContent> content = do_QueryInterface(target);
  if (content) {
    target = content->FindFirstNonChromeOnlyAccessContent();
  }
  NS_ENSURE_TRUE(target, false);

  nsCOMPtr<nsIDocument> document = GetDocument();
  if (NS_WARN_IF(!document)) {
    return false;
  }

  if (document->HasFlag(NODE_IS_EDITABLE)) {
    // If this editor is in designMode and the event target is the document,
    // the event is for this editor.
    nsCOMPtr<nsIDocument> targetDocument = do_QueryInterface(target);
    if (targetDocument) {
      return targetDocument == document;
    }
    // Otherwise, check whether the event target is in this document or not.
    nsCOMPtr<nsIContent> targetContent = do_QueryInterface(target);
    NS_ENSURE_TRUE(targetContent, false);
    return document == targetContent->GetUncomposedDoc();
  }

  // This HTML editor is for contenteditable.  We need to check the validity of
  // the target.
  nsCOMPtr<nsIContent> targetContent = do_QueryInterface(target);
  NS_ENSURE_TRUE(targetContent, false);

  // If the event is a mouse event, we need to check if the target content is
  // the focused editing host or its descendant.
  if (aGUIEvent->AsMouseEventBase()) {
    nsIContent* editingHost = GetActiveEditingHost();
    // If there is no active editing host, we cannot handle the mouse event
    // correctly.
    if (!editingHost) {
      return false;
    }
    // If clicked on non-editable root element but the body element is the
    // active editing host, we should assume that the click event is targetted.
    if (targetContent == document->GetRootElement() &&
        !targetContent->HasFlag(NODE_IS_EDITABLE) &&
        editingHost == document->GetBodyElement()) {
      targetContent = editingHost;
    }
    // If the target element is neither the active editing host nor a descendant
    // of it, we may not be able to handle the event.
    if (!nsContentUtils::ContentIsDescendantOf(targetContent, editingHost)) {
      return false;
    }
    // If the clicked element has an independent selection, we shouldn't
    // handle this click event.
    if (targetContent->HasIndependentSelection()) {
      return false;
    }
    // If the target content is editable, we should handle this event.
    return targetContent->HasFlag(NODE_IS_EDITABLE);
  }

  // If the target of the other events which target focused element isn't
  // editable or has an independent selection, this editor shouldn't handle the
  // event.
  if (!targetContent->HasFlag(NODE_IS_EDITABLE) ||
      targetContent->HasIndependentSelection()) {
    return false;
  }

  // Finally, check whether we're actually focused or not.  When we're not
  // focused, we should ignore the dispatched event by script (or something)
  // because content editable element needs selection in itself for editing.
  // However, when we're not focused, it's not guaranteed.
  return IsActiveInDOMWindow();
}

nsresult
HTMLEditor::GetPreferredIMEState(IMEState* aState)
{
  // HTML editor don't prefer the CSS ime-mode because IE didn't do so too.
  aState->mOpen = IMEState::DONT_CHANGE_OPEN_STATE;
  if (IsReadonly() || IsDisabled()) {
    aState->mEnabled = IMEState::DISABLED;
  } else {
    aState->mEnabled = IMEState::ENABLED;
  }
  return NS_OK;
}

already_AddRefed<nsIContent>
HTMLEditor::GetInputEventTargetContent()
{
  nsCOMPtr<nsIContent> target = GetActiveEditingHost();
  return target.forget();
}

Element*
HTMLEditor::GetEditorRoot() const
{
  return GetActiveEditingHost();
}

nsHTMLDocument*
HTMLEditor::GetHTMLDocument() const
{
  nsIDocument* doc = GetDocument();
  if (NS_WARN_IF(!doc)) {
    return nullptr;
  }
  if (!doc->IsHTMLOrXHTML()) {
    return nullptr;
  }
  return doc->AsHTMLDocument();
}

} // namespace mozilla