/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * The contents of this file are subject to the Netscape Public
 * License Version 1.1 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.mozilla.org/NPL/
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is Netscape
 * Communications Corporation.  Portions created by Netscape are
 * Copyright (C) 1998 Netscape Communications Corporation. All
 * Rights Reserved.
 *
 * Contributor(s): 
 *   Pierre Phaneuf <pp@ludusdesign.com>
 */
#include "nsICaret.h"


#include "nsHTMLEditor.h"
#include "nsHTMLEditRules.h"
#include "nsHTMLEditUtils.h"

#include "nsEditorEventListeners.h"

#include "nsIDOMText.h"
#include "nsIDOMNodeList.h"
#include "nsIDOMDocument.h"
#include "nsIDOMAttr.h"
#include "nsIDocument.h"
#include "nsIDOMEventReceiver.h" 
#include "nsIDOMKeyEvent.h"
#include "nsIDOMKeyListener.h" 
#include "nsIDOMMouseListener.h"
#include "nsIDOMMouseEvent.h"
#include "nsISelection.h"
#include "nsISelectionPrivate.h"
#include "nsIDOMHTMLAnchorElement.h"
#include "nsIDOMHTMLImageElement.h"
#include "nsISelectionController.h"

#include "nsIIndependentSelection.h" //domselections answer to frameselection

#include "nsICSSLoader.h"
#include "nsICSSStyleSheet.h"
#include "nsIHTMLContentContainer.h"
#include "nsIDocumentObserver.h"
#include "nsIDocumentStateListener.h"

#include "nsIStyleContext.h"

#include "nsIEnumerator.h"
#include "nsIContent.h"
#include "nsIContentIterator.h"
#include "nsEditorCID.h"
#include "nsLayoutCID.h"
#include "nsIDOMRange.h"
#include "nsIDOMNSRange.h"
#include "nsISupportsArray.h"
#include "nsVoidArray.h"
#include "nsFileSpec.h"
#include "nsIFile.h"
#include "nsIURL.h"
#include "nsIComponentManager.h"
#include "nsIServiceManager.h"
#include "nsWidgetsCID.h"
#include "nsIDocumentEncoder.h"
#include "nsIDOMDocumentFragment.h"
#include "nsIPresShell.h"
#include "nsIPresContext.h"
#include "nsIParser.h"
#include "nsParserCIID.h"
#include "nsIImage.h"
#include "nsAOLCiter.h"
#include "nsInternetCiter.h"
#include "nsISupportsPrimitives.h"
#include "InsertTextTxn.h"
#include "SetDocTitleTxn.h"

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

// Drag & Drop, Clipboard
#include "nsWidgetsCID.h"
#include "nsIClipboard.h"
#include "nsITransferable.h"
#include "nsIDragService.h"
#include "nsIDOMNSUIEvent.h"

// Transactionas
#include "PlaceholderTxn.h"
#include "nsStyleSheetTxns.h"

// Misc
#include "TextEditorTest.h"
#include "nsEditorUtils.h"
#include "nsIPref.h"

const PRUnichar nbsp = 160;

// HACK - CID for NS_CTRANSITIONAL_DTD_CID so that we can get at transitional dtd
#define NS_CTRANSITIONAL_DTD_CID \
{ 0x4611d482, 0x960a, 0x11d4, { 0x8e, 0xb0, 0xb6, 0x17, 0x66, 0x1b, 0x6f, 0x7c } }


static NS_DEFINE_CID(kHTMLEditorCID,  NS_HTMLEDITOR_CID);
static NS_DEFINE_CID(kCContentIteratorCID, NS_CONTENTITERATOR_CID);
static NS_DEFINE_IID(kSubtreeIteratorCID, NS_SUBTREEITERATOR_CID);
static NS_DEFINE_CID(kCRangeCID,      NS_RANGE_CID);
static NS_DEFINE_CID(kCDOMSelectionCID,      NS_DOMSELECTION_CID);
static NS_DEFINE_CID(kPrefServiceCID, NS_PREF_CID);
static NS_DEFINE_IID(kCParserIID, NS_IPARSER_IID); 
static NS_DEFINE_CID(kCParserCID, NS_PARSER_CID); 
static NS_DEFINE_CID(kCTransitionalDTDCID,  NS_CTRANSITIONAL_DTD_CID);

#if defined(NS_DEBUG) && defined(DEBUG_buster)
static PRBool gNoisy = PR_FALSE;
#else
static const PRBool gNoisy = PR_FALSE;
#endif

// Some utilities to handle annoying overloading of "A" tag for link and named anchor
static char hrefText[] = "href";
static char anchorTxt[] = "anchor";
static char namedanchorText[] = "namedanchor";

// some prototypes for rules creation shortcuts
nsresult NS_NewTextEditRules(nsIEditRules** aInstancePtrResult);
nsresult NS_NewHTMLEditRules(nsIEditRules** aInstancePtrResult);

#define IsLinkTag(s) (s.EqualsIgnoreCase(hrefText))
#define IsNamedAnchorTag(s) (s.EqualsIgnoreCase(anchorTxt) || s.EqualsIgnoreCase(namedanchorText))

nsHTMLEditor::nsHTMLEditor()
: nsPlaintextEditor()
, mIgnoreSpuriousDragEvent(PR_FALSE)
, mTypeInState(nsnull)
, mSelectedCellIndex(0)
{
// Done in nsEditor
// NS_INIT_REFCNT();
  mBoldAtom = getter_AddRefs(NS_NewAtom("b"));
  mItalicAtom = getter_AddRefs(NS_NewAtom("i"));
  mUnderlineAtom = getter_AddRefs(NS_NewAtom("u"));
  mFontAtom = getter_AddRefs(NS_NewAtom("font"));
  mLinkAtom = getter_AddRefs(NS_NewAtom("a"));
} 

nsHTMLEditor::~nsHTMLEditor()
{
  // remove the rules as an action listener.  Else we get a bad ownership loop later on.
  // it's ok if the rules aren't a listener; we ignore the error.
  nsCOMPtr<nsIEditActionListener> mListener = do_QueryInterface(mRules);
  RemoveEditActionListener(mListener);
  
  //the autopointers will clear themselves up. 
  //but we need to also remove the listeners or we have a leak
  nsCOMPtr<nsISelection>selection;
  nsresult result = GetSelection(getter_AddRefs(selection));
  // if we don't get the selection, just skip this
  if (NS_SUCCEEDED(result) && selection) 
  {
    nsCOMPtr<nsISelectionPrivate> selPriv(do_QueryInterface(selection));
    nsCOMPtr<nsISelectionListener>listener;
    listener = do_QueryInterface(mTypeInState);
    if (listener) {
      selPriv->RemoveSelectionListener(listener); 
    }
  }

  NS_IF_RELEASE(mTypeInState);
}

NS_IMPL_ADDREF_INHERITED(nsHTMLEditor, nsEditor)
NS_IMPL_RELEASE_INHERITED(nsHTMLEditor, nsEditor)


NS_IMETHODIMP nsHTMLEditor::QueryInterface(REFNSIID aIID, void** aInstancePtr)
{
  if (!aInstancePtr)
    return NS_ERROR_NULL_POINTER;
 
  *aInstancePtr = nsnull;
  
  if (aIID.Equals(NS_GET_IID(nsIPlaintextEditor))) {
    *aInstancePtr = NS_STATIC_CAST(nsIPlaintextEditor*, this);
    NS_ADDREF_THIS();
    return NS_OK;
  }
  if (aIID.Equals(NS_GET_IID(nsIHTMLEditor))) {
    *aInstancePtr = NS_STATIC_CAST(nsIHTMLEditor*, this);
    NS_ADDREF_THIS();
    return NS_OK;
  }
  if (aIID.Equals(NS_GET_IID(nsIEditorMailSupport))) {
    *aInstancePtr = NS_STATIC_CAST(nsIEditorMailSupport*, this);
    NS_ADDREF_THIS();
    return NS_OK;
  }
  if (aIID.Equals(NS_GET_IID(nsITableEditor))) {
    *aInstancePtr = NS_STATIC_CAST(nsITableEditor*, this);
    NS_ADDREF_THIS();
    return NS_OK;
  }
  if (aIID.Equals(NS_GET_IID(nsIEditorStyleSheets))) {
    *aInstancePtr = NS_STATIC_CAST(nsIEditorStyleSheets*, this);
    NS_ADDREF_THIS();
    return NS_OK;
  }
  if (aIID.Equals(NS_GET_IID(nsICSSLoaderObserver))) {
    *aInstancePtr = NS_STATIC_CAST(nsICSSLoaderObserver*, this);
    NS_ADDREF_THIS();
    return NS_OK;
  }

  return nsEditor::QueryInterface(aIID, aInstancePtr);
}


NS_IMETHODIMP nsHTMLEditor::Init(nsIDOMDocument *aDoc, 
                                 nsIPresShell   *aPresShell, nsIContent *aRoot, nsISelectionController *aSelCon, PRUint32 aFlags)
{
  NS_PRECONDITION(aDoc && aPresShell, "bad arg");
  if (!aDoc || !aPresShell)
    return NS_ERROR_NULL_POINTER;

  nsresult result = NS_OK, rulesRes = NS_OK;
  
  if (1)
  {
    // block to scope nsAutoEditInitRulesTrigger
    nsAutoEditInitRulesTrigger rulesTrigger(NS_STATIC_CAST(nsPlaintextEditor*,this), rulesRes);

    // Init the plaintext editor
    result = nsPlaintextEditor::Init(aDoc, aPresShell, aRoot, aSelCon, aFlags);
    if (NS_FAILED(result)) { return result; }

    // disable links
    nsCOMPtr<nsIPresContext> context;
    aPresShell->GetPresContext(getter_AddRefs(context));
    if (!context) return NS_ERROR_NULL_POINTER;
    if (!(mFlags & eEditorPlaintextMask))
      context->SetLinkHandler(0);  

    nsCOMPtr<nsIDOMElement> bodyElement;
    result = nsEditor::GetRootElement(getter_AddRefs(bodyElement));
    if (NS_FAILED(result)) { return result; }
    if (!bodyElement) { return NS_ERROR_NULL_POINTER; }

    // init the type-in state
    mTypeInState = new TypeInState();
    if (!mTypeInState) {return NS_ERROR_NULL_POINTER;}
    NS_ADDREF(mTypeInState);

    nsCOMPtr<nsISelection>selection;
    result = GetSelection(getter_AddRefs(selection));
    if (NS_FAILED(result)) { return result; }
    if (selection) 
    {
      nsCOMPtr<nsISelectionPrivate> selPriv(do_QueryInterface(selection));
      nsCOMPtr<nsISelectionListener>listener;
      listener = do_QueryInterface(mTypeInState);
      if (listener) {
        selPriv->AddSelectionListener(listener); 
      }
    }

    // Set up a DTD   
    mDTD = do_CreateInstance(kCTransitionalDTDCID);
    if (!mDTD) result = NS_ERROR_FAILURE;
  }

  if (NS_FAILED(rulesRes)) return rulesRes;
  return result;
}

NS_IMETHODIMP 
nsHTMLEditor::PostCreate()
{
  nsresult result = InstallEventListeners();
  if (NS_FAILED(result)) return result;

  result = nsEditor::PostCreate();
  return result;
}

NS_IMETHODIMP 
nsHTMLEditor::InstallEventListeners()
{
  NS_ASSERTION(mDocWeak, "no document set on this editor");
  if (!mDocWeak) return NS_ERROR_NOT_INITIALIZED;

  nsresult result;
  // get a key listener
  result = NS_NewEditorKeyListener(getter_AddRefs(mKeyListenerP), this);
  if (NS_FAILED(result)) {
    HandleEventListenerError();
    return result;
  }
  
  // get a mouse listener
  result = NS_NewEditorMouseListener(getter_AddRefs(mMouseListenerP), this);
  if (NS_FAILED(result)) {
    HandleEventListenerError();
    return result;
  }

  // get a text listener
  result = NS_NewEditorTextListener(getter_AddRefs(mTextListenerP),this);
  if (NS_FAILED(result)) { 
#ifdef DEBUG_TAGUE
printf("nsTextEditor.cpp: failed to get TextEvent Listener\n");
#endif
    HandleEventListenerError();
    return result;
  }

  // get a composition listener
  result = NS_NewEditorCompositionListener(getter_AddRefs(mCompositionListenerP),this);
  if (NS_FAILED(result)) { 
#ifdef DEBUG_TAGUE
printf("nsTextEditor.cpp: failed to get TextEvent Listener\n");
#endif
    HandleEventListenerError();
    return result;
  }

  // get a drag listener
  result = NS_NewEditorDragListener(getter_AddRefs(mDragListenerP), this);
  if (NS_FAILED(result)) {
    HandleEventListenerError();
    return result;
  }

  // get a focus listener
  result = NS_NewEditorFocusListener(getter_AddRefs(mFocusListenerP), this);
  if (NS_FAILED(result)) {
    HandleEventListenerError();
    return result;
  }

  nsCOMPtr<nsIDOMEventReceiver> erP;
  result = GetDOMEventReceiver(getter_AddRefs(erP));

  //end hack
  if (NS_FAILED(result)) {
    HandleEventListenerError();
    return result;
  }

  // register the event listeners with the DOM event reveiver
  result = erP->AddEventListenerByIID(mKeyListenerP, NS_GET_IID(nsIDOMKeyListener));
  NS_ASSERTION(NS_SUCCEEDED(result), "failed to register key listener");
  if (NS_SUCCEEDED(result))
  {
    result = erP->AddEventListenerByIID(mMouseListenerP, NS_GET_IID(nsIDOMMouseListener));
    NS_ASSERTION(NS_SUCCEEDED(result), "failed to register mouse listener");
    if (NS_SUCCEEDED(result))
    {
      result = erP->AddEventListenerByIID(mFocusListenerP, NS_GET_IID(nsIDOMFocusListener));
      NS_ASSERTION(NS_SUCCEEDED(result), "failed to register focus listener");
      if (NS_SUCCEEDED(result))
      {
        result = erP->AddEventListenerByIID(mTextListenerP, NS_GET_IID(nsIDOMTextListener));
        NS_ASSERTION(NS_SUCCEEDED(result), "failed to register text listener");
        if (NS_SUCCEEDED(result))
        {
          result = erP->AddEventListenerByIID(mCompositionListenerP, NS_GET_IID(nsIDOMCompositionListener));
          NS_ASSERTION(NS_SUCCEEDED(result), "failed to register composition listener");
          if (NS_SUCCEEDED(result))
          {
            result = erP->AddEventListenerByIID(mDragListenerP, NS_GET_IID(nsIDOMDragListener));
            NS_ASSERTION(NS_SUCCEEDED(result), "failed to register drag listener");
          }
        }
      }
    }
  }
  if (NS_FAILED(result)) {
    HandleEventListenerError();
  }
  return result;
}

NS_IMETHODIMP 
nsHTMLEditor::GetFlags(PRUint32 *aFlags)
{
  if (!mRules || !aFlags) { return NS_ERROR_NULL_POINTER; }
  return mRules->GetFlags(aFlags);
}


NS_IMETHODIMP 
nsHTMLEditor::SetFlags(PRUint32 aFlags)
{
  if (!mRules) { return NS_ERROR_NULL_POINTER; }
  return mRules->SetFlags(aFlags);
}


NS_IMETHODIMP nsHTMLEditor::InitRules()
{
  // instantiate the rules for the html editor
  nsresult res = NS_NewHTMLEditRules(getter_AddRefs(mRules));
  if (NS_FAILED(res)) return res;
  if (!mRules) return NS_ERROR_UNEXPECTED;
  res = mRules->Init(NS_STATIC_CAST(nsPlaintextEditor*,this), mFlags);
  
  return res;
}

NS_IMETHODIMP 
nsHTMLEditor::SetDocumentTitle(const PRUnichar *aTitle)
{
  SetDocTitleTxn *txn;
  nsresult result = TransactionFactory::GetNewTransaction(SetDocTitleTxn::GetCID(), (EditTxn **)&txn);
  if (NS_SUCCEEDED(result))  
  {
    nsAutoString title(aTitle);
    result = txn->Init(this, &title);

    if (NS_SUCCEEDED(result)) 
    {
      result = nsEditor::Do(txn);  
    }
    // The transaction system (if any) has taken ownwership of txn
    NS_IF_RELEASE(txn);
  }
  return result;
}

PRBool nsHTMLEditor::IsModifiable()
{
  PRUint32 flags;
  if (NS_SUCCEEDED(GetFlags(&flags)))
    return ((flags & eEditorReadonlyMask) == 0);
  else
    return PR_FALSE;
}


#ifdef XP_MAC
#pragma mark -
#pragma mark  nsIHTMLEditor methods 
#pragma mark -
#endif

NS_IMETHODIMP nsHTMLEditor::HandleKeyPress(nsIDOMKeyEvent* aKeyEvent)
{
  PRUint32 keyCode, character;
  PRBool   isShift, ctrlKey, altKey, metaKey;
  nsresult res;

  if (!aKeyEvent) return NS_ERROR_NULL_POINTER;

  if (NS_SUCCEEDED(aKeyEvent->GetKeyCode(&keyCode)) && 
      NS_SUCCEEDED(aKeyEvent->GetShiftKey(&isShift)) &&
      NS_SUCCEEDED(aKeyEvent->GetCtrlKey(&ctrlKey)) &&
      NS_SUCCEEDED(aKeyEvent->GetAltKey(&altKey)) &&
      NS_SUCCEEDED(aKeyEvent->GetMetaKey(&metaKey)))
  {
    // this royally blows: because tabs come in from keyDowns instead
    // of keyPress, and because GetCharCode refuses to work for keyDown
    // i have to play games.
    if (keyCode == nsIDOMKeyEvent::DOM_VK_TAB) character = '\t';
    else aKeyEvent->GetCharCode(&character);
    
    if (keyCode == nsIDOMKeyEvent::DOM_VK_TAB && !(mFlags&eEditorPlaintextBit))
    {
      nsCOMPtr<nsISelection>selection;
      res = GetSelection(getter_AddRefs(selection));
      if (NS_FAILED(res)) return res;
      PRInt32 offset;
      nsCOMPtr<nsIDOMNode> node, blockParent;
      res = GetStartNodeAndOffset(selection, address_of(node), &offset);
      if (NS_FAILED(res)) return res;
      if (!node) return NS_ERROR_FAILURE;
  
      if (IsBlockNode(node)) blockParent = node;
      else blockParent = GetBlockNodeParent(node);
      
      if (blockParent)
      {
        PRBool bHandled = PR_FALSE;
        
        if (nsHTMLEditUtils::IsTableElement(blockParent))
          res = TabInTable(isShift, &bHandled);
        else if (nsHTMLEditUtils::IsListItem(blockParent))
        {
          nsAutoString indentstr;
          if (isShift) indentstr.AssignWithConversion("outdent");
          else         indentstr.AssignWithConversion("indent");
          res = Indent(indentstr);
          bHandled = PR_TRUE;
        }
        if (NS_FAILED(res)) return res;
        if (bHandled) return res;
      }
    }
    else if (keyCode == nsIDOMKeyEvent::DOM_VK_RETURN
             || keyCode == nsIDOMKeyEvent::DOM_VK_ENTER)
    {
      nsString empty;
      if (isShift && !(mFlags&eEditorPlaintextBit))
      {
        return TypedText(empty.GetUnicode(), eTypedBR);  // only inserts a br node
      }
      else 
      {
        return TypedText(empty.GetUnicode(), eTypedBreak);  // uses rules to figure out what to insert
      }
    }
    else if (keyCode == nsIDOMKeyEvent::DOM_VK_ESCAPE)
    {
      // pass escape keypresses through as empty strings: needed forime support
      nsString empty;
      return TypedText(empty.GetUnicode(), eTypedText);
    }
    
    // if we got here we either fell out of the tab case or have a normal character.
    // Either way, treat as normal character.
    if (character && !altKey && !ctrlKey && !isShift && !metaKey)
    {
      nsAutoString key(character);
      return TypedText(key.GetUnicode(), eTypedText);
    }
  }
  return NS_ERROR_FAILURE;
}

/* This routine is needed to provide a bottleneck for typing for logging
   purposes.  Can't use EditorKeyPress() (above) for that since it takes
   a nsIDOMUIEvent* parameter.  So instead we pass enough info through
   to TypedText() to determine what action to take, but without passing
   an event.
   */
NS_IMETHODIMP nsHTMLEditor::TypedText(const PRUnichar* aString,
                                      PRInt32 aAction)
{
  nsAutoPlaceHolderBatch batch(this, gTypingTxnName);

  switch (aAction)
  {
    case eTypedText:
    case eTypedBreak:
      {
        return nsPlaintextEditor::TypedText(aString, aAction);
      }
    case eTypedBR:
      {
        nsCOMPtr<nsIDOMNode> brNode;
        return InsertBR(address_of(brNode));  // only inserts a br node
      }
  } 
  return NS_ERROR_FAILURE; 
}

NS_IMETHODIMP nsHTMLEditor::TabInTable(PRBool inIsShift, PRBool *outHandled)
{
  if (!outHandled) return NS_ERROR_NULL_POINTER;
  *outHandled = PR_FALSE;

  // Find enclosing table cell from the selection (cell may be the selected element)
  nsCOMPtr<nsIDOMElement> cellElement;
    // can't use |NS_LITERAL_STRING| here until |GetElementOrParentByTagName| is fixed to accept readables
  nsresult res = GetElementOrParentByTagName(NS_ConvertASCIItoUCS2("td"), nsnull, getter_AddRefs(cellElement));
  if (NS_FAILED(res)) return res;
  // Do nothing -- we didn't find a table cell
  if (!cellElement) return NS_OK;

  // find enclosing table
  nsCOMPtr<nsIDOMNode> tbl = GetEnclosingTable(cellElement);
  if (!tbl) return res;

  // advance to next cell
  // first create an iterator over the table
  nsCOMPtr<nsIContentIterator> iter;
  res = nsComponentManager::CreateInstance(kCContentIteratorCID, nsnull,
                                           NS_GET_IID(nsIContentIterator), 
                                           getter_AddRefs(iter));
  if (NS_FAILED(res)) return res;
  if (!iter) return NS_ERROR_NULL_POINTER;
  nsCOMPtr<nsIContent> cTbl = do_QueryInterface(tbl);
  nsCOMPtr<nsIContent> cBlock = do_QueryInterface(cellElement);
  res = iter->Init(cTbl);
  if (NS_FAILED(res)) return res;
  // position iter at block
  res = iter->PositionAt(cBlock);
  if (NS_FAILED(res)) return res;
  nsCOMPtr<nsIDOMNode> node;
  nsCOMPtr<nsIContent> cNode;
  do
  {
    if (inIsShift) res = iter->Prev();
    else res = iter->Next();
    if (NS_FAILED(res)) break;
    res = iter->CurrentNode(getter_AddRefs(cNode));
    if (NS_FAILED(res)) break;
    node = do_QueryInterface(cNode);
    if (nsHTMLEditUtils::IsTableCell(node) && (GetEnclosingTable(node) == tbl))
    {
      res = CollapseSelectionToDeepestNonTableFirstChild(nsnull, node);
      if (NS_FAILED(res)) return res;
      *outHandled = PR_TRUE;
      return NS_OK;
    }
  } while (iter->IsDone() == NS_ENUMERATOR_FALSE);
  
  if (!(*outHandled) && !inIsShift)
  {
    // if we havent handled it yet then we must have run off the end of
    // the table.  Insert a new row.
    res = InsertTableRow(1, PR_TRUE);
    if (NS_FAILED(res)) return res;
    *outHandled = PR_TRUE;
    // put selection in right place
    // Use table code to get selection and index to new row...
    nsCOMPtr<nsISelection>selection;
    nsCOMPtr<nsIDOMElement> tblElement;
    nsCOMPtr<nsIDOMElement> cell;
    PRInt32 row;
    res = GetCellContext(getter_AddRefs(selection), 
                         getter_AddRefs(tblElement),
                         getter_AddRefs(cell), 
                         nsnull, nsnull,
                         &row, nsnull);
    if (NS_FAILED(res)) return res;
    // ...so that we can ask for first cell in that row...
    res = GetCellAt(tblElement, row, 0, getter_AddRefs(cell));
    if (NS_FAILED(res)) return res;
    // ...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)
    node = do_QueryInterface(cell);
    if (node) selection->Collapse(node,0);
    return NS_OK;
  }
  
  return res;
}

NS_IMETHODIMP nsHTMLEditor::CreateBRImpl(nsCOMPtr<nsIDOMNode> *aInOutParent, PRInt32 *aInOutOffset, nsCOMPtr<nsIDOMNode> *outBRNode, EDirection aSelect)
{
  if (!aInOutParent || !*aInOutParent || !aInOutOffset || !outBRNode) return NS_ERROR_NULL_POINTER;
  *outBRNode = nsnull;
  nsresult res;
  
  // we need to insert a br.  unfortunately, we may have to split a text node to do it.
  nsCOMPtr<nsIDOMNode> node = *aInOutParent;
  PRInt32 theOffset = *aInOutOffset;
  nsCOMPtr<nsIDOMCharacterData> nodeAsText = do_QueryInterface(node);
  nsAutoString brType; brType.AssignWithConversion("br");
  nsCOMPtr<nsIDOMNode> brNode;
  if (nodeAsText)  
  {
    nsCOMPtr<nsIDOMNode> tmp;
    PRInt32 offset;
    PRUint32 len;
    nodeAsText->GetLength(&len);
    GetNodeLocation(node, address_of(tmp), &offset);
    if (!tmp) return NS_ERROR_FAILURE;
    if (!theOffset)
    {
      // we are already set to go
    }
    else if (theOffset == (PRInt32)len)
    {
      // update offset to point AFTER the text node
      offset++;
    }
    else
    {
      // split the text node
      res = SplitNode(node, theOffset, getter_AddRefs(tmp));
      if (NS_FAILED(res)) return res;
      res = GetNodeLocation(node, address_of(tmp), &offset);
      if (NS_FAILED(res)) return res;
    }
    // create br
    res = CreateNode(brType, tmp, offset, getter_AddRefs(brNode));
    if (NS_FAILED(res)) return res;
    *aInOutParent = tmp;
    *aInOutOffset = offset+1;
  }
  else
  {
    res = CreateNode(brType, node, theOffset, getter_AddRefs(brNode));
    if (NS_FAILED(res)) return res;
    (*aInOutOffset)++;
  }

  *outBRNode = brNode;
  if (*outBRNode && (aSelect != eNone))
  {
    nsCOMPtr<nsISelection> selection;
    nsCOMPtr<nsIDOMNode> parent;
    PRInt32 offset;
    res = GetSelection(getter_AddRefs(selection));
    if (NS_FAILED(res)) return res;
    nsCOMPtr<nsISelectionPrivate> selPriv(do_QueryInterface(selection));
    res = GetNodeLocation(*outBRNode, address_of(parent), &offset);
    if (NS_FAILED(res)) return res;
    if (aSelect == eNext)
    {
      // position selection after br
      selPriv->SetInterlinePosition(PR_TRUE);
      res = selection->Collapse(parent, offset+1);
    }
    else if (aSelect == ePrevious)
    {
      // position selection before br
      selPriv->SetInterlinePosition(PR_TRUE);
      res = selection->Collapse(parent, offset);
    }
  }
  return NS_OK;
}


NS_IMETHODIMP nsHTMLEditor::CreateBR(nsIDOMNode *aNode, PRInt32 aOffset, nsCOMPtr<nsIDOMNode> *outBRNode, EDirection aSelect)
{
  nsCOMPtr<nsIDOMNode> parent = aNode;
  PRInt32 offset = aOffset;
  return CreateBRImpl(address_of(parent), &offset, outBRNode, aSelect);
}

NS_IMETHODIMP nsHTMLEditor::InsertBR(nsCOMPtr<nsIDOMNode> *outBRNode)
{
  PRBool bCollapsed;
  nsCOMPtr<nsISelection> selection;

  if (!outBRNode) return NS_ERROR_NULL_POINTER;
  *outBRNode = nsnull;

  // calling it text insertion to trigger moz br treatment by rules
  nsAutoRules beginRulesSniffing(this, kOpInsertText, nsIEditor::eNext);

  nsresult res = GetSelection(getter_AddRefs(selection));
  if (NS_FAILED(res)) return res;
  nsCOMPtr<nsISelectionPrivate> selPriv(do_QueryInterface(selection));
  res = selection->GetIsCollapsed(&bCollapsed);
  if (NS_FAILED(res)) return res;
  if (!bCollapsed)
  {
    res = DeleteSelection(nsIEditor::eNone);
    if (NS_FAILED(res)) return res;
  }
  nsCOMPtr<nsIDOMNode> selNode;
  PRInt32 selOffset;
  res = GetStartNodeAndOffset(selection, address_of(selNode), &selOffset);
  if (NS_FAILED(res)) return res;
  
  res = CreateBR(selNode, selOffset, outBRNode);
  if (NS_FAILED(res)) return res;
    
  // position selection after br
  res = GetNodeLocation(*outBRNode, address_of(selNode), &selOffset);
  if (NS_FAILED(res)) return res;
  selPriv->SetInterlinePosition(PR_TRUE);
  res = selection->Collapse(selNode, selOffset+1);
  
  return res;
}

nsresult 
nsHTMLEditor::GetDOMEventReceiver(nsIDOMEventReceiver **aEventReceiver) 
{ 
  if (!aEventReceiver) 
    return NS_ERROR_NULL_POINTER; 

  *aEventReceiver = 0; 

  nsCOMPtr<nsIDOMElement> rootElement; 

  nsresult result = GetRootElement(getter_AddRefs(rootElement)); 

  if (NS_FAILED(result)) 
    return result; 

  if (!rootElement) 
    return NS_ERROR_FAILURE; 

  // Now hack to make sure we are not anonymous content. 
  // If we are grab the parent of root element for our observer. 

  nsCOMPtr<nsIContent> content = do_QueryInterface(rootElement); 

  if (content) 
  { 
    nsCOMPtr<nsIContent> parent; 
    if (NS_SUCCEEDED(content->GetParent(*getter_AddRefs(parent))) && parent) 
    { 
      PRInt32 index; 
      if (NS_FAILED(parent->IndexOf(content, index)) || index < 0 ) 
      { 
        rootElement = do_QueryInterface(parent); //this will put listener on the form element basically 
        result = rootElement->QueryInterface(NS_GET_IID(nsIDOMEventReceiver), (void **)aEventReceiver); 
      } 
      else 
        rootElement = 0; // Let the event receiver work on the document instead of the root element 
    } 
  } 
  else 
    rootElement = 0; 

  if (!rootElement && mDocWeak) 
  { 
    // Don't use getDocument here, because we have no way of knowing if 
    // Init() was ever called.  So we need to get the document ourselves, 
    // if it exists. 

    nsCOMPtr<nsIDOMDocument> domdoc = do_QueryReferent(mDocWeak); 

    if (!domdoc) 
      return NS_ERROR_FAILURE; 

    result = domdoc->QueryInterface(NS_GET_IID(nsIDOMEventReceiver), (void **)aEventReceiver); 
  } 

  return result; 
} 
  
NS_IMETHODIMP 
nsHTMLEditor::CollapseSelectionToStart()
{
  nsCOMPtr<nsIDOMElement> bodyElement;
  nsresult res = nsEditor::GetRootElement(getter_AddRefs(bodyElement));
  if (NS_FAILED(res)) return res;
  if (!bodyElement)   return NS_ERROR_NULL_POINTER;
  nsCOMPtr<nsIDOMNode> bodyNode = do_QueryInterface(bodyElement);
  return CollapseSelectionToDeepestNonTableFirstChild(nsnull, bodyNode);  
}

nsresult 
nsHTMLEditor::CollapseSelectionToDeepestNonTableFirstChild(nsISelection *aSelection, nsIDOMNode *aNode)
{
  if (!aNode) return NS_ERROR_NULL_POINTER;
  nsresult res;

  nsCOMPtr<nsISelection> selection;
  if (aSelection)
  {
    selection = aSelection;
  } else {
    res = GetSelection(getter_AddRefs(selection));
    if (NS_FAILED(res)) return res;
    if (!selection) return NS_ERROR_FAILURE;
  }
  nsCOMPtr<nsIDOMNode> node = aNode;
  nsCOMPtr<nsIDOMNode> child;
  
  do {
    node->GetFirstChild(getter_AddRefs(child));
    
    if (child)
    {
      // Stop if we find a table
      // don't want to go into nested tables
      if (nsHTMLEditUtils::IsTable(child)) break;
      // hey, it'g gotta be a container too!
      if (!IsContainer(child)) break;
      node = child;
    }
  }
  while (child);

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


// This is mostly like InsertHTMLWithCharset, 
//  but we can't use that because it is selection-based and 
//  the rules code won't let us edit under the <head> node
NS_IMETHODIMP
nsHTMLEditor::ReplaceHeadContentsWithHTML(const nsString &aSourceToInsert)
{
  nsCOMPtr<nsISelection> selection;
  nsresult res = GetSelection(getter_AddRefs(selection));
  if (NS_FAILED(res)) return res;
  if (!selection) return NS_ERROR_NULL_POINTER;

  ForceCompositionEnd();

  // Do not use nsAutoRules -- rules code won't let us insert in <head>
  // Use the head node as a parent and delete/insert directly
  nsCOMPtr<nsIDOMNodeList>nodeList; 
  nsAutoString headTag; headTag.AssignWithConversion("head"); 

  nsCOMPtr<nsIDOMDocument> doc = do_QueryReferent(mDocWeak);
  if (!doc) return NS_ERROR_NOT_INITIALIZED;
  res = doc->GetElementsByTagName(headTag, getter_AddRefs(nodeList));
  if (NS_FAILED(res)) return res;
  if (!nodeList) return NS_ERROR_NULL_POINTER;

  PRUint32 count; 
  nodeList->GetLength(&count);
  if (count < 1) return NS_ERROR_FAILURE;

  nsCOMPtr<nsIDOMNode> headNode;
  res = nodeList->Item(0, getter_AddRefs(headNode)); 
  if (NS_FAILED(res)) return res;
  if (!headNode) return NS_ERROR_NULL_POINTER;

  // 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);  // hope this does copy-on-write
 
  // Windows linebreaks: Map CRLF to LF:
  inputString.ReplaceSubstring(NS_ConvertASCIItoUCS2("\r\n"),
                               NS_ConvertASCIItoUCS2("\n"));
 
  // Mac linebreaks: Map any remaining CR to LF:
  inputString.ReplaceSubstring(NS_ConvertASCIItoUCS2("\r"),
                               NS_ConvertASCIItoUCS2("\n"));

  nsAutoEditBatch beginBatching(this);

  res = GetSelection(getter_AddRefs(selection));
  if (NS_FAILED(res)) return res;
  if (!selection) return NS_ERROR_NULL_POINTER;

  // Get the first range in the selection, for context:
  nsCOMPtr<nsIDOMRange> range;
  res = selection->GetRangeAt(0, getter_AddRefs(range));
  if (NS_FAILED(res))
    return res;

  nsCOMPtr<nsIDOMNSRange> nsrange (do_QueryInterface(range));
  if (!nsrange)
    return NS_ERROR_NO_INTERFACE;
  nsCOMPtr<nsIDOMDocumentFragment> docfrag;
  res = nsrange->CreateContextualFragment(inputString,
                                          getter_AddRefs(docfrag));

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

  if (NS_FAILED(res))
  {
#ifdef DEBUG
    printf("Couldn't create contextual fragment: error was %d\n", res);
#endif
    return res;
  }
  if (!docfrag) return NS_ERROR_NULL_POINTER;

  nsCOMPtr<nsIDOMNode> child;

  // First delete all children in head
  do {
    res = headNode->GetFirstChild(getter_AddRefs(child));
    if (NS_FAILED(res)) return res;
    if (child)
    {
      res = DeleteNode(child);
      if (NS_FAILED(res)) return res;
    }
  } while (child);

  // Now insert the new nodes
  PRInt32 offsetOfNewNode = 0;
  nsCOMPtr<nsIDOMNode> fragmentAsNode (do_QueryInterface(docfrag));

  // Loop over the contents of the fragment and move into the document
  do {
    res = fragmentAsNode->GetFirstChild(getter_AddRefs(child));
    if (NS_FAILED(res)) return res;
    if (child)
    {
      res = InsertNode(child, headNode, offsetOfNewNode++);
      if (NS_FAILED(res)) return res;
    }
  } while (child);

  return res;
}

NS_IMETHODIMP
nsHTMLEditor::RebuildDocumentFromSource(const nsString& aSourceString)
{
  ForceCompositionEnd();

  nsCOMPtr<nsISelection>selection;
  nsresult res = GetSelection(getter_AddRefs(selection));
  if (NS_FAILED(res)) return res;

  nsCOMPtr<nsIDOMElement> bodyElement;
  res = GetRootElement(getter_AddRefs(bodyElement));
  if (NS_FAILED(res)) return res;
  if (!bodyElement) return NS_ERROR_NULL_POINTER;

  // Find where the <body> tag starts.
  // If user mangled that, then abort
  PRInt32 bodyStart = aSourceString.Find(NS_ConvertASCIItoUCS2("<body"), PR_TRUE);
  if (bodyStart == -1) return NS_ERROR_FAILURE;

  PRInt32 headStart = aSourceString.Find(NS_ConvertASCIItoUCS2("<head"), PR_TRUE);
  if (headStart == -1) return NS_ERROR_FAILURE;

  // Find the index after "<head>"
  PRInt32 headEnd = aSourceString.Find(NS_ConvertASCIItoUCS2("</head"), PR_TRUE);

  // We'll be forgiving and assume head ends before body
  if (headEnd == -1) headEnd = bodyStart;
  nsAutoString headString;
  aSourceString.Mid(headString, headStart, (headEnd - headStart));
  
  nsAutoString bodyString;
  aSourceString.Mid(bodyString, bodyStart, (aSourceString.Length() - bodyStart - 1));
  
  // Time to change the document
  nsAutoEditBatch beginBatching(this);

  // Try to replace body contents first
  res = SelectAll();
  if (NS_FAILED(res)) return res;

  res = InsertHTML(bodyString);
  if (NS_FAILED(res)) return res;
  selection->Collapse(bodyElement, 0);

  res = ReplaceHeadContentsWithHTML(headString);
  if (NS_FAILED(res)) return res;

  // 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
  nsAutoString bodyTag;
  // Truncate at the end of the body tag
  PRInt32 bodyTagEnd = bodyString.FindChar((PRUnichar)'>', PR_FALSE, 5);
  if (bodyTagEnd == -1) return NS_ERROR_FAILURE;
  bodyString.Truncate(bodyTagEnd+1);
  
  // Kludge of the year: fool the parser by replacing "body" with "div" so we get a node
  bodyString.ToLowerCase();
  bodyString.ReplaceSubstring(NS_ConvertASCIItoUCS2("body"), NS_ConvertASCIItoUCS2("div"));

  nsCOMPtr<nsIDOMRange> range;
  res = selection->GetRangeAt(0, getter_AddRefs(range));
  if (NS_FAILED(res)) return res;

  nsCOMPtr<nsIDOMNSRange> nsrange (do_QueryInterface(range));
  if (!nsrange) return NS_ERROR_NO_INTERFACE;

  nsCOMPtr<nsIDOMDocumentFragment> docfrag;
  res = nsrange->CreateContextualFragment(bodyString, getter_AddRefs(docfrag));
  if (NS_FAILED(res)) return res;

  nsCOMPtr<nsIDOMNode> fragmentAsNode (do_QueryInterface(docfrag));
  if (!fragmentAsNode) return NS_ERROR_NULL_POINTER;
  
  nsCOMPtr<nsIDOMNode> child;
  res = fragmentAsNode->GetFirstChild(getter_AddRefs(child));
  if (NS_FAILED(res)) return res;
  if (!child) return NS_ERROR_NULL_POINTER;
  
  // Copy all attributes from the div child to current body element
  return CloneAttributes(bodyElement, child);
}

NS_IMETHODIMP
nsHTMLEditor::InsertElementAtSelection(nsIDOMElement* aElement, PRBool aDeleteSelection)
{
  nsresult res = NS_ERROR_NOT_INITIALIZED;
  
  if (!aElement)
    return NS_ERROR_NULL_POINTER;
  
  nsCOMPtr<nsIDOMNode> node = do_QueryInterface(aElement);
  
  ForceCompositionEnd();
  nsAutoEditBatch beginBatching(this);
  nsAutoRules beginRulesSniffing(this, kOpInsertElement, nsIEditor::eNext);

  nsCOMPtr<nsISelection>selection;
  res = GetSelection(getter_AddRefs(selection));
  if (!NS_SUCCEEDED(res) || !selection)
    return NS_ERROR_FAILURE;

  // hand off to the rules system, see if it has anything to say about this
  PRBool cancel, handled;
  nsTextRulesInfo ruleInfo(nsTextEditRules::kInsertElement);
  ruleInfo.insertElement = aElement;
  res = mRules->WillDoAction(selection, &ruleInfo, &cancel, &handled);
  if (cancel || (NS_FAILED(res))) return res;

  if (!handled)
  {
    if (aDeleteSelection)
    {
      nsCOMPtr<nsIDOMNode> tempNode;
      PRInt32 tempOffset;
      nsresult result = DeleteSelectionAndPrepareToCreateNode(tempNode,tempOffset);
      if (!NS_SUCCEEDED(result))
        return result;
    }

    // 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 (nsHTMLEditUtils::IsNamedAnchor(node))
      {
        selection->CollapseToStart();
      } else {
        selection->CollapseToEnd();
      }
    }

    nsCOMPtr<nsIDOMNode> parentSelectedNode;
    PRInt32 offsetForInsert;
    res = selection->GetAnchorNode(getter_AddRefs(parentSelectedNode));
    // XXX: ERROR_HANDLING bad XPCOM usage
    if (NS_SUCCEEDED(res) && NS_SUCCEEDED(selection->GetAnchorOffset(&offsetForInsert)) && parentSelectedNode)
    {
#ifdef DEBUG_cmanske
      {
      nsAutoString name;
      parentSelectedNode->GetNodeName(name);
      printf("InsertElement: Anchor node of selection: ");
      wprintf(name.GetUnicode());
      printf(" Offset: %d\n", offsetForInsert);
      }
#endif

      res = InsertNodeAtPoint(node, parentSelectedNode, offsetForInsert, PR_FALSE);
      NS_ENSURE_SUCCESS(res, res);
      // Set caret after element, but check for special case 
      //  of inserting table-related elements: set in first cell instead
      if (!SetCaretInTableCell(aElement))
        res = SetCaretAfterElement(aElement);

    }
  }
  res = mRules->DidDoAction(selection, &ruleInfo, res);
  return res;
}

nsresult
nsHTMLEditor::InsertNodeAtPoint(nsIDOMNode *aNode, 
                                nsIDOMNode *aParent, 
                                PRInt32 aOffset, 
                                PRBool aNoEmptyNodes)
{
  NS_ENSURE_TRUE(aNode, NS_ERROR_NULL_POINTER);
  NS_ENSURE_TRUE(aParent, NS_ERROR_NULL_POINTER);
  
  nsresult res = NS_OK;
  nsAutoString tagName;
  aNode->GetNodeName(tagName);
  tagName.ToLowerCase();
  nsCOMPtr<nsIDOMNode> parent = aParent;
  nsCOMPtr<nsIDOMNode> topChild = aParent;
  nsCOMPtr<nsIDOMNode> tmp;
  PRInt32 offsetOfInsert = aOffset;
   
  // Search up the parent chain to find a suitable container      
  while (!CanContainTag(parent, tagName))
  {
    // If the current parent is a root (body or table element)
    // then go no further - we can't insert
    if (nsHTMLEditUtils::IsBody(parent) || nsHTMLEditUtils::IsTableElement(parent))
      return NS_ERROR_FAILURE;
    // Get the next parent
    parent->GetParentNode(getter_AddRefs(tmp));
    NS_ENSURE_TRUE(tmp, NS_ERROR_FAILURE);
    topChild = parent;
    parent = tmp;
  }
  if (parent != topChild)
  {
    // we need to split some levels above the original selection parent
    res = SplitNodeDeep(topChild, aParent, aOffset, &offsetOfInsert, aNoEmptyNodes);
    if (NS_FAILED(res))
      return res;
  }
  // Now we can insert the new node
  res = InsertNode(aNode, parent, offsetOfInsert);
  return res;
}

NS_IMETHODIMP
nsHTMLEditor::SelectElement(nsIDOMElement* aElement)
{
  nsresult res = NS_ERROR_NULL_POINTER;

  // Must be sure that element is contained in the document body
  if (IsElementInBody(aElement))
  {
    nsCOMPtr<nsISelection> selection;
    res = GetSelection(getter_AddRefs(selection));
    if (NS_FAILED(res)) return res;
    if (!selection) return NS_ERROR_NULL_POINTER;
    nsCOMPtr<nsIDOMNode>parent;
    res = aElement->GetParentNode(getter_AddRefs(parent));
    if (NS_SUCCEEDED(res) && parent)
    {
      PRInt32 offsetInParent;
      res = GetChildOffset(aElement, parent, offsetInParent);

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

NS_IMETHODIMP
nsHTMLEditor::SetCaretAfterElement(nsIDOMElement* aElement)
{
  nsresult res = NS_ERROR_NULL_POINTER;

  // Be sure the element is contained in the document body
  if (aElement && IsElementInBody(aElement))
  {
    nsCOMPtr<nsISelection> selection;
    res = GetSelection(getter_AddRefs(selection));
    if (NS_FAILED(res)) return res;
    if (!selection) return NS_ERROR_NULL_POINTER;
    nsCOMPtr<nsIDOMNode>parent;
    res = aElement->GetParentNode(getter_AddRefs(parent));
    if (NS_FAILED(res)) return res;
    if (!parent) return NS_ERROR_NULL_POINTER;
    PRInt32 offsetInParent;
    res = GetChildOffset(aElement, parent, offsetInParent);
    if (NS_SUCCEEDED(res))
    {
      // Collapse selection to just after desired element,
      res = selection->Collapse(parent, offsetInParent+1);
#if 0 //def DEBUG_cmanske
      {
      nsAutoString name;
      parent->GetNodeName(name);
      printf("SetCaretAfterElement: Parent node: ");
      wprintf(name.GetUnicode());
      printf(" Offset: %d\n\nHTML:\n", offsetInParent+1);
      nsAutoString Format("text/html");
      nsAutoString ContentsAs;
      OutputToString(ContentsAs, Format, 2);
      wprintf(ContentsAs.GetUnicode());
      }
#endif
    }
  }
  return res;
}

NS_IMETHODIMP 
nsHTMLEditor::SetParagraphFormat(const nsString& aParagraphFormat)
{
  nsAutoString tag; tag.Assign(aParagraphFormat);
  tag.ToLowerCase();
  if (tag.EqualsWithConversion("dd") || tag.EqualsWithConversion("dt"))
    return MakeDefinitionItem(tag);
  else
    return InsertBasicBlock(tag);
}

// XXX: ERROR_HANDLING -- this method needs a little work to ensure all error codes are 
//                        checked properly, all null pointers are checked, and no memory leaks occur
NS_IMETHODIMP 
nsHTMLEditor::GetParentBlockTags(nsStringArray *aTagList, PRBool aGetLists)
{
  if (!aTagList) { return NS_ERROR_NULL_POINTER; }

  nsresult res;
  nsCOMPtr<nsISelection>selection;
  res = GetSelection(getter_AddRefs(selection));
  if (NS_FAILED(res)) return res;
  if (!selection) return NS_ERROR_NULL_POINTER;
  nsCOMPtr<nsISelectionPrivate> selPriv(do_QueryInterface(selection));

  // Find out if the selection is collapsed:
  PRBool isCollapsed;
  res = selection->GetIsCollapsed(&isCollapsed);
  if (NS_FAILED(res)) return res;
  if (isCollapsed)
  {
    nsCOMPtr<nsIDOMNode> node, blockParent;
    PRInt32 offset;
  
    res = GetStartNodeAndOffset(selection, address_of(node), &offset);
    if (!node) res = NS_ERROR_FAILURE;
    if (NS_FAILED(res)) return res;
  
    nsCOMPtr<nsIDOMElement> blockParentElem;
    if (aGetLists)
    {
      // Get the "ol", "ul", or "dl" parent element
      res = GetElementOrParentByTagName(NS_ConvertASCIItoUCS2("list"), node, getter_AddRefs(blockParentElem));
      if (NS_FAILED(res)) return res;
    } 
    else 
    {
      if (IsBlockNode(node)) blockParent = node;
      else blockParent = GetBlockNodeParent(node);
      blockParentElem = do_QueryInterface(blockParent);
    }
    if (blockParentElem)
    {
      nsAutoString blockParentTag;
      blockParentElem->GetTagName(blockParentTag);
      aTagList->AppendString(blockParentTag);
    }
    
    return res;
  }

  // else non-collapsed selection
  nsCOMPtr<nsIEnumerator> enumerator;
  res = selPriv->GetEnumerator(getter_AddRefs(enumerator));
  if (NS_FAILED(res)) return res;
  if (!enumerator) return NS_ERROR_NULL_POINTER;

  enumerator->First(); 
  nsCOMPtr<nsISupports> currentItem;
  res = enumerator->CurrentItem(getter_AddRefs(currentItem));
  if (NS_FAILED(res)) return res;
  //XXX: should be while loop?
  if (currentItem)
  {
    nsCOMPtr<nsIDOMRange> range( do_QueryInterface(currentItem) );
    // scan the range for all the independent block content blockSections
    // and get the block parent of each
    nsISupportsArray *blockSections;
    res = NS_NewISupportsArray(&blockSections);
    if (NS_FAILED(res)) return res;
    if (!blockSections) return NS_ERROR_NULL_POINTER;
    res = GetBlockSectionsForRange(range, blockSections);
    if (NS_SUCCEEDED(res))
    {
      nsIDOMRange *subRange;
      subRange = (nsIDOMRange *)(blockSections->ElementAt(0));
      while (subRange)
      {
        nsCOMPtr<nsIDOMNode>startParent;
        res = subRange->GetStartContainer(getter_AddRefs(startParent));
        if (NS_SUCCEEDED(res) && startParent) 
        {
          nsCOMPtr<nsIDOMElement> blockParent;
          if (aGetLists)
          {
            // Get the "ol", "ul", or "dl" parent element
            res = GetElementOrParentByTagName(NS_ConvertASCIItoUCS2("list"), startParent, getter_AddRefs(blockParent));
          } 
          else 
          {
            blockParent = do_QueryInterface(GetBlockNodeParent(startParent));
          }
          if (NS_SUCCEEDED(res) && blockParent)
          {
            nsAutoString blockParentTag;
            blockParent->GetTagName(blockParentTag);
            PRBool isRoot;
            IsRootTag(blockParentTag, isRoot);
            if ((!isRoot) && (-1==aTagList->IndexOf(blockParentTag))) {
              aTagList->AppendString(blockParentTag);
            }
          }
        }
        NS_RELEASE(subRange);
        if (NS_FAILED(res))
          break;  // don't return here, need to release blockSections
        blockSections->RemoveElementAt(0);
        subRange = (nsIDOMRange *)(blockSections->ElementAt(0));
      }
    }
    NS_RELEASE(blockSections);
  }
  return res;
}


NS_IMETHODIMP 
nsHTMLEditor::GetParagraphState(PRBool &aMixed, nsString &outFormat)
{
  if (!mRules) { return NS_ERROR_NOT_INITIALIZED; }

  nsCOMPtr<nsIHTMLEditRules> htmlRules = do_QueryInterface(mRules);
  if (!htmlRules) return NS_ERROR_FAILURE;
  
  return htmlRules->GetParagraphState(aMixed, outFormat);
}

NS_IMETHODIMP 
nsHTMLEditor::GetBackgroundColorState(PRBool &aMixed, nsString &aOutColor)
{
  //TODO: We don't handle "mixed" correctly!
  aMixed = PR_FALSE;
  aOutColor.AssignWithConversion("");
  
  nsCOMPtr<nsIDOMElement> element;
  PRInt32 selectedCount;
  nsAutoString tagName;
  nsresult res = GetSelectedOrParentTableElement(*getter_AddRefs(element), tagName, selectedCount);
  if (NS_FAILED(res)) return res;

  nsAutoString styleName; styleName.AssignWithConversion("bgcolor");

  while (element)
  {
    // We are in a cell or selected table
    res = element->GetAttribute(styleName, aOutColor);
    if (NS_FAILED(res)) return res;

    // Done if we have a color explicitly set
    if (aOutColor.Length() > 0)
      return NS_OK;

    // Once we hit the body, we're done
    if(nsHTMLEditUtils::IsBody(element)) return NS_OK;

    // No color is set, but we need to report visible color inherited 
    // from nested cells/tables, so search up parent chain
    nsCOMPtr<nsIDOMNode> parentNode;
    res = element->GetParentNode(getter_AddRefs(parentNode));
    if (NS_FAILED(res)) return res;
    element = do_QueryInterface(parentNode);
  }

  // If no table or cell found, get page body
  res = nsEditor::GetRootElement(getter_AddRefs(element));
  if (NS_FAILED(res)) return res;
  if (!element) return NS_ERROR_NULL_POINTER;

  return element->GetAttribute(styleName, aOutColor);
}

NS_IMETHODIMP 
nsHTMLEditor::GetListState(PRBool &aMixed, PRBool &aOL, PRBool &aUL, PRBool &aDL)
{
  if (!mRules) { return NS_ERROR_NOT_INITIALIZED; }

  nsCOMPtr<nsIHTMLEditRules> htmlRules = do_QueryInterface(mRules);
  if (!htmlRules) return NS_ERROR_FAILURE;
  
  return htmlRules->GetListState(aMixed, aOL, aUL, aDL);
}

NS_IMETHODIMP 
nsHTMLEditor::GetListItemState(PRBool &aMixed, PRBool &aLI, PRBool &aDT, PRBool &aDD)
{
  if (!mRules) { return NS_ERROR_NOT_INITIALIZED; }

  nsCOMPtr<nsIHTMLEditRules> htmlRules = do_QueryInterface(mRules);
  if (!htmlRules) return NS_ERROR_FAILURE;
  
  return htmlRules->GetListItemState(aMixed, aLI, aDT, aDD);
}

NS_IMETHODIMP
nsHTMLEditor::GetAlignment(PRBool &aMixed, nsIHTMLEditor::EAlignment &aAlign)
{
  if (!mRules) { return NS_ERROR_NOT_INITIALIZED; }

  nsCOMPtr<nsIHTMLEditRules> htmlRules = do_QueryInterface(mRules);
  if (!htmlRules) return NS_ERROR_FAILURE;
  
  return htmlRules->GetAlignment(aMixed, aAlign);
}


NS_IMETHODIMP 
nsHTMLEditor::GetIndentState(PRBool &aCanIndent, PRBool &aCanOutdent)
{
  if (!mRules) { return NS_ERROR_NOT_INITIALIZED; }

  nsCOMPtr<nsIHTMLEditRules> htmlRules = do_QueryInterface(mRules);
  if (!htmlRules) return NS_ERROR_FAILURE;
  
  return htmlRules->GetIndentState(aCanIndent, aCanOutdent);
}

NS_IMETHODIMP
nsHTMLEditor::MakeOrChangeList(const nsString& aListType, PRBool entireList)
{
  nsresult res;
  if (!mRules) { return NS_ERROR_NOT_INITIALIZED; }

  nsCOMPtr<nsISelection> selection;
  PRBool cancel, handled;

  nsAutoEditBatch beginBatching(this);
  nsAutoRules beginRulesSniffing(this, kOpMakeList, nsIEditor::eNext);
  
  // pre-process
  res = GetSelection(getter_AddRefs(selection));
  if (NS_FAILED(res)) return res;
  if (!selection) return NS_ERROR_NULL_POINTER;

  nsTextRulesInfo ruleInfo(nsTextEditRules::kMakeList);
  ruleInfo.blockType = &aListType;
  ruleInfo.entireList = entireList;
  res = mRules->WillDoAction(selection, &ruleInfo, &cancel, &handled);
  if (cancel || (NS_FAILED(res))) return res;

  if (!handled)
  {
    // Find out if the selection is collapsed:
    PRBool isCollapsed;
    res = selection->GetIsCollapsed(&isCollapsed);
    if (NS_FAILED(res)) return res;

    nsCOMPtr<nsIDOMNode> node;
    PRInt32 offset;
  
    res = GetStartNodeAndOffset(selection, address_of(node), &offset);
    if (!node) res = NS_ERROR_FAILURE;
    if (NS_FAILED(res)) return res;
  
    if (isCollapsed)
    {
      // have to find a place to put the list
      nsCOMPtr<nsIDOMNode> parent = node;
      nsCOMPtr<nsIDOMNode> topChild = node;
      nsCOMPtr<nsIDOMNode> tmp;
    
      while ( !CanContainTag(parent, aListType))
      {
        parent->GetParentNode(getter_AddRefs(tmp));
        if (!tmp) return NS_ERROR_FAILURE;
        topChild = parent;
        parent = tmp;
      }
    
      if (parent != node)
      {
        // we need to split up to the child of parent
        res = SplitNodeDeep(topChild, node, offset, &offset);
        if (NS_FAILED(res)) return res;
      }

      // make a list
      nsCOMPtr<nsIDOMNode> newList;
      res = CreateNode(aListType, parent, offset, getter_AddRefs(newList));
      if (NS_FAILED(res)) return res;
      // make a list item
      nsAutoString tag; tag.AssignWithConversion("li");
      nsCOMPtr<nsIDOMNode> newItem;
      res = CreateNode(tag, newList, 0, getter_AddRefs(newItem));
      if (NS_FAILED(res)) return res;
      res = selection->Collapse(newItem,0);
      if (NS_FAILED(res)) return res;
    }
  }
  
  res = mRules->DidDoAction(selection, &ruleInfo, res);
  return res;
}


NS_IMETHODIMP
nsHTMLEditor::RemoveList(const nsString& aListType)
{
  nsresult res;
  if (!mRules) { return NS_ERROR_NOT_INITIALIZED; }

  nsCOMPtr<nsISelection> selection;
  PRBool cancel, handled;

  nsAutoEditBatch beginBatching(this);
  nsAutoRules beginRulesSniffing(this, kOpRemoveList, nsIEditor::eNext);
  
  // pre-process
  res = GetSelection(getter_AddRefs(selection));
  if (NS_FAILED(res)) return res;
  if (!selection) return NS_ERROR_NULL_POINTER;

  nsTextRulesInfo ruleInfo(nsTextEditRules::kRemoveList);
  if (aListType.EqualsWithConversion("ol")) ruleInfo.bOrdered = PR_TRUE;
  else  ruleInfo.bOrdered = PR_FALSE;
  res = mRules->WillDoAction(selection, &ruleInfo, &cancel, &handled);
  if (cancel || (NS_FAILED(res))) return res;

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

  res = mRules->DidDoAction(selection, &ruleInfo, res);
  return res;
}

nsresult
nsHTMLEditor::MakeDefinitionItem(const nsString& aItemType)
{
  nsresult res;
  if (!mRules) { return NS_ERROR_NOT_INITIALIZED; }

  nsCOMPtr<nsISelection> selection;
  PRBool cancel, handled;

  nsAutoEditBatch beginBatching(this);
  nsAutoRules beginRulesSniffing(this, kOpMakeDefListItem, nsIEditor::eNext);
  
  // pre-process
  res = GetSelection(getter_AddRefs(selection));
  if (NS_FAILED(res)) return res;
  if (!selection) return NS_ERROR_NULL_POINTER;
  nsTextRulesInfo ruleInfo(nsTextEditRules::kMakeDefListItem);
  ruleInfo.blockType = &aItemType;
  res = mRules->WillDoAction(selection, &ruleInfo, &cancel, &handled);
  if (cancel || (NS_FAILED(res))) return res;

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

  res = mRules->DidDoAction(selection, &ruleInfo, res);
  return res;
}

nsresult
nsHTMLEditor::InsertBasicBlock(const nsString& aBlockType)
{
  nsresult res;
  if (!mRules) { return NS_ERROR_NOT_INITIALIZED; }

  nsCOMPtr<nsISelection> selection;
  PRBool cancel, handled;

  nsAutoEditBatch beginBatching(this);
  nsAutoRules beginRulesSniffing(this, kOpMakeBasicBlock, nsIEditor::eNext);
  
  // pre-process
  res = GetSelection(getter_AddRefs(selection));
  if (NS_FAILED(res)) return res;
  if (!selection) return NS_ERROR_NULL_POINTER;
  nsTextRulesInfo ruleInfo(nsTextEditRules::kMakeBasicBlock);
  ruleInfo.blockType = &aBlockType;
  res = mRules->WillDoAction(selection, &ruleInfo, &cancel, &handled);
  if (cancel || (NS_FAILED(res))) return res;

  if (!handled)
  {
    // Find out if the selection is collapsed:
    PRBool isCollapsed;
    res = selection->GetIsCollapsed(&isCollapsed);
    if (NS_FAILED(res)) return res;

    nsCOMPtr<nsIDOMNode> node;
    PRInt32 offset;
  
    res = GetStartNodeAndOffset(selection, address_of(node), &offset);
    if (!node) res = NS_ERROR_FAILURE;
    if (NS_FAILED(res)) return res;
  
    if (isCollapsed)
    {
      // have to find a place to put the block
      nsCOMPtr<nsIDOMNode> parent = node;
      nsCOMPtr<nsIDOMNode> topChild = node;
      nsCOMPtr<nsIDOMNode> tmp;
    
      while ( !CanContainTag(parent, aBlockType))
      {
        parent->GetParentNode(getter_AddRefs(tmp));
        if (!tmp) return NS_ERROR_FAILURE;
        topChild = parent;
        parent = tmp;
      }
    
      if (parent != node)
      {
        // we need to split up to the child of parent
        res = SplitNodeDeep(topChild, node, offset, &offset);
        if (NS_FAILED(res)) return res;
      }

      // make a block
      nsCOMPtr<nsIDOMNode> newBlock;
      res = CreateNode(aBlockType, parent, offset, getter_AddRefs(newBlock));
      if (NS_FAILED(res)) return res;
    
      // reposition selection to inside the block
      res = selection->Collapse(newBlock,0);
      if (NS_FAILED(res)) return res;  
    }
  }

  res = mRules->DidDoAction(selection, &ruleInfo, res);
  return res;
}

NS_IMETHODIMP
nsHTMLEditor::Indent(const nsString& aIndent)
{
  nsresult res;
  if (!mRules) { return NS_ERROR_NOT_INITIALIZED; }

  PRBool cancel, handled;
  PRInt32 theAction = nsTextEditRules::kIndent;
  PRInt32 opID = kOpIndent;
  if (aIndent.EqualsWithConversion("outdent"))
  {
    theAction = nsTextEditRules::kOutdent;
    opID = kOpOutdent;
  }
  nsAutoEditBatch beginBatching(this);
  nsAutoRules beginRulesSniffing(this, opID, nsIEditor::eNext);
  
  // pre-process
  nsCOMPtr<nsISelection> selection;
  res = GetSelection(getter_AddRefs(selection));
  if (NS_FAILED(res)) return res;
  if (!selection) return NS_ERROR_NULL_POINTER;

  nsTextRulesInfo ruleInfo(theAction);
  res = mRules->WillDoAction(selection, &ruleInfo, &cancel, &handled);
  if (cancel || (NS_FAILED(res))) return res;
  
  if (!handled)
  {
    // Do default - insert a blockquote node if selection collapsed
    nsCOMPtr<nsIDOMNode> node;
    PRInt32 offset;
    PRBool isCollapsed;
    res = selection->GetIsCollapsed(&isCollapsed);
    if (NS_FAILED(res)) return res;

    res = GetStartNodeAndOffset(selection, address_of(node), &offset);
    if (!node) res = NS_ERROR_FAILURE;
    if (NS_FAILED(res)) return res;
  
    nsAutoString inward; inward.AssignWithConversion("indent");
    if (aIndent == inward)
    {
      if (isCollapsed)
      {
        // have to find a place to put the blockquote
        nsCOMPtr<nsIDOMNode> parent = node;
        nsCOMPtr<nsIDOMNode> topChild = node;
        nsCOMPtr<nsIDOMNode> tmp;
        nsAutoString bq(NS_LITERAL_STRING("blockquote"));
        while ( !CanContainTag(parent, bq))
        {
          parent->GetParentNode(getter_AddRefs(tmp));
          if (!tmp) return NS_ERROR_FAILURE;
          topChild = parent;
          parent = tmp;
        }
    
        if (parent != node)
        {
          // we need to split up to the child of parent
          res = SplitNodeDeep(topChild, node, offset, &offset);
          if (NS_FAILED(res)) return res;
        }

        // make a blockquote
        nsCOMPtr<nsIDOMNode> newBQ;
        res = CreateNode(bq, parent, offset, getter_AddRefs(newBQ));
        if (NS_FAILED(res)) return res;
        // put a space in it so layout will draw the list item
        res = selection->Collapse(newBQ,0);
        if (NS_FAILED(res)) return res;
        res = InsertText(NS_LITERAL_STRING(" ").get());
        if (NS_FAILED(res)) return res;
        // reposition selection to before the space character
        res = GetStartNodeAndOffset(selection, address_of(node), &offset);
        if (NS_FAILED(res)) return res;
        res = selection->Collapse(node,0);
        if (NS_FAILED(res)) return res;
      }
    }
  }
  res = mRules->DidDoAction(selection, &ruleInfo, res);
  return res;
}

//TODO: IMPLEMENT ALIGNMENT!

NS_IMETHODIMP
nsHTMLEditor::Align(const nsString& aAlignType)
{
  nsAutoEditBatch beginBatching(this);
  nsAutoRules beginRulesSniffing(this, kOpAlign, nsIEditor::eNext);

  nsCOMPtr<nsIDOMNode> node;
  PRBool cancel, handled;
  
  // Find out if the selection is collapsed:
  nsCOMPtr<nsISelection> selection;
  nsresult res = GetSelection(getter_AddRefs(selection));
  if (NS_FAILED(res)) return res;
  if (!selection) return NS_ERROR_NULL_POINTER;
  nsTextRulesInfo ruleInfo(nsTextEditRules::kAlign);
  ruleInfo.alignType = &aAlignType;
  res = mRules->WillDoAction(selection, &ruleInfo, &cancel, &handled);
  if (cancel || NS_FAILED(res))
    return res;
  
  res = mRules->DidDoAction(selection, &ruleInfo, res);
  return res;
}

NS_IMETHODIMP
nsHTMLEditor::GetElementOrParentByTagName(const nsAReadableString& aTagName, nsIDOMNode *aNode, nsIDOMElement** aReturn)
{
  if (aTagName.Length() == 0 || !aReturn )
    return NS_ERROR_NULL_POINTER;
  
  nsresult res = NS_OK;
  nsCOMPtr<nsIDOMNode> currentNode;

  if (aNode)
    currentNode = aNode;
  else
  {
    // If no node supplied, get it from anchor node of current selection
    nsCOMPtr<nsISelection>selection;
    res = GetSelection(getter_AddRefs(selection));
    if (NS_FAILED(res)) return res;
    if (!selection) return NS_ERROR_NULL_POINTER;

    nsCOMPtr<nsIDOMNode> anchorNode;
    res = selection->GetAnchorNode(getter_AddRefs(anchorNode));
    if(NS_FAILED(res)) return res;
    if (!anchorNode)  return NS_ERROR_FAILURE;

    // Try to get the actual selected node
    PRBool hasChildren = PR_FALSE;
    anchorNode->HasChildNodes(&hasChildren);
    if (hasChildren)
    {
      PRInt32 offset;
      res = selection->GetAnchorOffset(&offset);
      if(NS_FAILED(res)) return res;
      currentNode = nsEditor::GetChildAt(anchorNode, offset);
    }
    // anchor node is probably a text node - just use that
    if (!currentNode)
      currentNode = anchorNode;
  }
   
  nsAutoString TagName(aTagName);
  TagName.ToLowerCase();
  PRBool getLink = IsLinkTag(TagName);
  PRBool getNamedAnchor = IsNamedAnchorTag(TagName);
  if ( getLink || getNamedAnchor)
  {
    TagName.AssignWithConversion("a");  
  }
  PRBool findTableCell = TagName.EqualsWithConversion("td");
  PRBool findList = TagName.EqualsWithConversion("list");

  // default is null - no element found
  *aReturn = nsnull;
  
  nsCOMPtr<nsIDOMNode> parent;
  PRBool bNodeFound = PR_FALSE;

  while (PR_TRUE)
  {
    nsAutoString currentTagName; 
    // Test if we have a link (an anchor with href set)
    if ( (getLink && nsHTMLEditUtils::IsLink(currentNode)) ||
         (getNamedAnchor && nsHTMLEditUtils::IsNamedAnchor(currentNode)) )
    {
      bNodeFound = PR_TRUE;
      break;
    } else {
      if (findList)
      {
        // Match "ol", "ul", or "dl" for lists
        if (nsHTMLEditUtils::IsList(currentNode))
          goto NODE_FOUND;

      } else if (findTableCell)
      {
        // Table cells are another special case:
        // Match either "td" or "th" for them
        if (nsHTMLEditUtils::IsTableCell(currentNode))
          goto NODE_FOUND;

      } else {
        currentNode->GetNodeName(currentTagName);
        if (currentTagName.EqualsIgnoreCase(TagName))
        {
NODE_FOUND:
          bNodeFound = PR_TRUE;
          break;
        } 
      }
    }
    // Search up the parent chain
    // We should never fail because of root test below, but lets be safe
    // XXX: ERROR_HANDLING error return code lost
    if (!NS_SUCCEEDED(currentNode->GetParentNode(getter_AddRefs(parent))) || !parent)
      break;

    // Stop searching if parent is a body tag
    nsAutoString parentTagName;
    parent->GetNodeName(parentTagName);
    // Note: Originally used IsRoot to stop at table cells,
    //  but that's too messy when you are trying to find the parent table
    //PRBool isRoot;
    //if (!NS_SUCCEEDED(IsRootTag(parentTagName, isRoot)) || isRoot)
    if(parentTagName.EqualsIgnoreCase("body"))
      break;

    currentNode = parent;
  }
  if (bNodeFound)
  {
    nsCOMPtr<nsIDOMElement> currentElement = do_QueryInterface(currentNode);
    if (currentElement)
    {
      *aReturn = currentElement;
      // Getters must addref
      NS_ADDREF(*aReturn);
    }
  }
  else res = NS_EDITOR_ELEMENT_NOT_FOUND;

  return res;
}

NS_IMETHODIMP
nsHTMLEditor::GetSelectedElement(const nsString& aTagName, nsIDOMElement** aReturn)
{
  if (!aReturn )
    return NS_ERROR_NULL_POINTER;
  
  // default is null - no element found
  *aReturn = nsnull;
  
  // First look for a single element in selection
  nsCOMPtr<nsISelection>selection;
  nsresult res = GetSelection(getter_AddRefs(selection));
  if (NS_FAILED(res)) return res;
  if (!selection) return NS_ERROR_NULL_POINTER;
  nsCOMPtr<nsISelectionPrivate> selPriv(do_QueryInterface(selection));

  PRBool bNodeFound = PR_FALSE;
  res=NS_ERROR_NOT_INITIALIZED;
  PRBool isCollapsed;
  selection->GetIsCollapsed(&isCollapsed);

  nsAutoString domTagName;
  nsAutoString TagName(aTagName);
  TagName.ToLowerCase();
  // Empty string indicates we should match any element tag
  PRBool anyTag = (TagName.IsEmpty());
  PRBool isLinkTag = IsLinkTag(TagName);
  PRBool isNamedAnchorTag = IsNamedAnchorTag(TagName);
  
  nsCOMPtr<nsIDOMElement> selectedElement;
  nsCOMPtr<nsIDOMRange> range;
  res = selection->GetRangeAt(0, getter_AddRefs(range));
  if (NS_FAILED(res)) return res;

  nsCOMPtr<nsIDOMNode> startParent;
  PRInt32 startOffset, endOffset;
  res = range->GetStartContainer(getter_AddRefs(startParent));
  if (NS_FAILED(res)) return res;
  res = range->GetStartOffset(&startOffset);
  if (NS_FAILED(res)) return res;

  nsCOMPtr<nsIDOMNode> endParent;
  res = range->GetEndContainer(getter_AddRefs(endParent));
  if (NS_FAILED(res)) return res;
  res = range->GetEndOffset(&endOffset);
  if (NS_FAILED(res)) return res;

  // Optimization for a single selected element
  if (startParent && startParent == endParent && (endOffset-startOffset) == 1)
  {
    nsCOMPtr<nsIDOMNode> selectedNode = GetChildAt(startParent, startOffset);
    if (NS_FAILED(res)) return NS_OK;
    if (selectedNode)
    {
      selectedNode->GetNodeName(domTagName);
      domTagName.ToLowerCase();

      // Test for appropriate node type requested
      if (anyTag || (TagName == domTagName) ||
          (isLinkTag && nsHTMLEditUtils::IsLink(selectedNode)) ||
          (isNamedAnchorTag && nsHTMLEditUtils::IsNamedAnchor(selectedNode)))
      {
        bNodeFound = PR_TRUE;
        selectedElement = do_QueryInterface(selectedNode);
      }
    }
  }

  if (!bNodeFound)
  {
    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)
      nsCOMPtr<nsIDOMNode> anchorNode;
      res = selection->GetAnchorNode(getter_AddRefs(anchorNode));
      if (NS_FAILED(res)) return res;
      PRInt32 anchorOffset = -1;
      if (anchorNode)
        selection->GetAnchorOffset(&anchorOffset);
    
      nsCOMPtr<nsIDOMNode> focusNode;
      res = selection->GetFocusNode(getter_AddRefs(focusNode));
      if (NS_FAILED(res)) return res;
      PRInt32 focusOffset = -1;
      if (focusNode)
        selection->GetFocusOffset(&focusOffset);

      // Link node must be the same for both ends of selection
      if (NS_SUCCEEDED(res) && anchorNode)
      {
  #ifdef DEBUG_cmanske
        {
        nsAutoString name;
        anchorNode->GetNodeName(name);
        printf("GetSelectedElement: Anchor node of selection: ");
        wprintf(name.GetUnicode());
        printf(" Offset: %d\n", anchorOffset);
        focusNode->GetNodeName(name);
        printf("Focus node of selection: ");
        wprintf(name.GetUnicode());
        printf(" Offset: %d\n", focusOffset);
        }
  #endif
        nsCOMPtr<nsIDOMElement> parentLinkOfAnchor;
        res = GetElementOrParentByTagName(NS_ConvertASCIItoUCS2("href"), anchorNode, getter_AddRefs(parentLinkOfAnchor));
        // XXX: ERROR_HANDLING  can parentLinkOfAnchor be null?
        if (NS_SUCCEEDED(res) && parentLinkOfAnchor)
        {
          if (isCollapsed)
          {
            // We have just a caret in the link
            bNodeFound = PR_TRUE;
          } else if(focusNode) 
          {  // Link node must be the same for both ends of selection
            nsCOMPtr<nsIDOMElement> parentLinkOfFocus;
            res = GetElementOrParentByTagName(NS_ConvertASCIItoUCS2("href"), focusNode, getter_AddRefs(parentLinkOfFocus));
            if (NS_SUCCEEDED(res) && parentLinkOfFocus == parentLinkOfAnchor)
              bNodeFound = PR_TRUE;
          }
      
          // We found a link node parent
          if (bNodeFound) {
            // GetElementOrParentByTagName addref'd this, so we don't need to do it here
            *aReturn = parentLinkOfAnchor;
            NS_IF_ADDREF(*aReturn);
            return NS_OK;
          }
        }
        else if (anchorOffset >= 0)  // Check if link node is the only thing selected
        {
          nsCOMPtr<nsIDOMNode> anchorChild;
          anchorChild = GetChildAt(anchorNode,anchorOffset);
          if (anchorChild && nsHTMLEditUtils::IsLink(anchorChild) && 
              (anchorNode == focusNode) && focusOffset == (anchorOffset+1))
          {
            selectedElement = do_QueryInterface(anchorChild);
            bNodeFound = PR_TRUE;
          }
        }
      }
    } 

    if (!isCollapsed)   // Don't bother to examine selection if it is collapsed
    {
      nsCOMPtr<nsIEnumerator> enumerator;
      res = selPriv->GetEnumerator(getter_AddRefs(enumerator));
      if (NS_SUCCEEDED(res))
      {
        if(!enumerator)
          return NS_ERROR_NULL_POINTER;

        enumerator->First(); 
        nsCOMPtr<nsISupports> currentItem;
        res = enumerator->CurrentItem(getter_AddRefs(currentItem));
        if ((NS_SUCCEEDED(res)) && currentItem)
        {
          nsCOMPtr<nsIDOMRange> currange( do_QueryInterface(currentItem) );
          nsCOMPtr<nsIContentIterator> iter;
          res = nsComponentManager::CreateInstance(kCContentIteratorCID, nsnull,
                                                      NS_GET_IID(nsIContentIterator), 
                                                      getter_AddRefs(iter));
          if (NS_FAILED(res)) return res;
          if (iter)
          {
            iter->Init(currange);
            // loop through the content iterator for each content node
            nsCOMPtr<nsIContent> content;
            while (NS_ENUMERATOR_FALSE == iter->IsDone())
            {
              res = iter->CurrentNode(getter_AddRefs(content));
              // Note likely!
              if (NS_FAILED(res))
                return NS_ERROR_FAILURE;

               // Query interface to cast nsIContent to nsIDOMNode
               //  then get tagType to compare to  aTagName
               // Clone node of each desired type and append it to the aDomFrag
              selectedElement = do_QueryInterface(content);
              if (selectedElement)
              {
                // If we already found a node, then we have another element,
                //  thus there's not just one element selected
                if (bNodeFound)
                {
                  bNodeFound = PR_FALSE;
                  break;
                }

                selectedElement->GetNodeName(domTagName);
                domTagName.ToLowerCase();

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

                // The "A" tag is a pain,
                //  used for both link(href is set) and "Named Anchor"
                nsCOMPtr<nsIDOMNode> selectedNode = do_QueryInterface(selectedElement);
                if ( (isLinkTag && nsHTMLEditUtils::IsLink(selectedNode)) ||
                     (isNamedAnchorTag && nsHTMLEditUtils::IsNamedAnchor(selectedNode)) )
                {
                  bNodeFound = PR_TRUE;
                } else if (TagName == domTagName) { // All other tag names are handled here
                  bNodeFound = PR_TRUE;
                }
                if (!bNodeFound)
                {
                  // Check if node we have is really part of the selection???
                  break;
                }
              }
              iter->Next();
            }
          }
        } else {
          // Should never get here?
          isCollapsed = PR_TRUE;
          printf("isCollapsed was FALSE, but no elements found in selection\n");
        }
      } else {
        printf("Could not create enumerator for GetSelectionProperties\n");
      }
    }
  }
  if (bNodeFound)
  {
    
    *aReturn = selectedElement;
    if (selectedElement)
    {  
      // Getters must addref
      NS_ADDREF(*aReturn);
    }
  } 
  else res = NS_EDITOR_ELEMENT_NOT_FOUND;

  return res;
}

NS_IMETHODIMP
nsHTMLEditor::CreateElementWithDefaults(const nsAReadableString& aTagName, nsIDOMElement** aReturn)
{
  nsresult res=NS_ERROR_NOT_INITIALIZED;
  if (aReturn)
    *aReturn = nsnull;

  if (aTagName.IsEmpty() || !aReturn)
//  if (!aTagName || !aReturn)
    return NS_ERROR_NULL_POINTER;
    
  nsAutoString TagName(aTagName);
  TagName.ToLowerCase();
  nsAutoString realTagName;

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

  nsCOMPtr<nsIDOMElement>newElement;
  nsCOMPtr<nsIContent> newContent;
  nsCOMPtr<nsIDOMDocument> doc = do_QueryReferent(mDocWeak);
  if (!doc) return NS_ERROR_NOT_INITIALIZED;

  //new call to use instead to get proper HTML element, bug# 39919
  res = CreateHTMLContent(realTagName, getter_AddRefs(newContent));
  newElement = do_QueryInterface(newContent);
  if (NS_FAILED(res) || !newElement)
    return NS_ERROR_FAILURE;

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

  // Set default values for new elements
  if (TagName.EqualsWithConversion("hr"))
  {
    // Note that we read the user's attributes for these from prefs (in InsertHLine JS)
    newElement->SetAttribute(NS_LITERAL_STRING("align"),NS_LITERAL_STRING("center"));
    newElement->SetAttribute(NS_LITERAL_STRING("width"),NS_LITERAL_STRING("100%"));
    newElement->SetAttribute(NS_LITERAL_STRING("size"),NS_LITERAL_STRING("2"));
  } else if (TagName.EqualsWithConversion("table"))
  {
    newElement->SetAttribute(NS_LITERAL_STRING("cellpadding"),NS_LITERAL_STRING("2"));
    newElement->SetAttribute(NS_LITERAL_STRING("cellspacing"),NS_LITERAL_STRING("2"));
    newElement->SetAttribute(NS_LITERAL_STRING("border"),NS_LITERAL_STRING("1"));
  } else if (TagName.EqualsWithConversion("td"))
  {
    newElement->SetAttribute(NS_LITERAL_STRING("valign"),NS_LITERAL_STRING("top"));
  }
  // ADD OTHER TAGS HERE

  if (NS_SUCCEEDED(res))
  {
    *aReturn = newElement;
    // Getters must addref
    NS_ADDREF(*aReturn);
  }

  return res;
}

NS_IMETHODIMP
nsHTMLEditor::InsertLinkAroundSelection(nsIDOMElement* aAnchorElement)
{
  nsresult res=NS_ERROR_NULL_POINTER;
  nsCOMPtr<nsISelection> selection;

  if (!aAnchorElement) return NS_ERROR_NULL_POINTER; 


  // We must have a real selection
  res = GetSelection(getter_AddRefs(selection));
  if (!selection)
  {
    res = NS_ERROR_NULL_POINTER;
  }
  if (NS_FAILED(res)) return res;
  if (!selection) return NS_ERROR_NULL_POINTER;

  PRBool isCollapsed;
  res = selection->GetIsCollapsed(&isCollapsed);
  if (NS_FAILED(res))
    isCollapsed = PR_TRUE;
  
  if (isCollapsed)
  {
    printf("InsertLinkAroundSelection called but there is no selection!!!\n");     
    res = NS_OK;
  } else {
    // Be sure we were given an anchor element
    nsCOMPtr<nsIDOMHTMLAnchorElement> anchor = do_QueryInterface(aAnchorElement);
    if (anchor)
    {
      nsAutoString href;
      res = anchor->GetHref(href);
      if (NS_FAILED(res)) return res;
      if (href.GetUnicode() && href.Length() > 0)      
      {
        nsAutoEditBatch beginBatching(this);
        nsString attribute; attribute.AssignWithConversion("href");
        SetInlineProperty(nsIEditProperty::a, &attribute, &href);
        //TODO: Enumerate through other properties of the anchor tag
        // and set those as well. 
        // Optimization: Modify SetTextProperty to set all attributes at once?
      }
    }
  }
  return res;
}

NS_IMETHODIMP 
nsHTMLEditor::SetBackgroundColor(const nsString& aColor)
{
  NS_PRECONDITION(mDocWeak, "Missing Editor DOM Document");
  
  // Find a selected or enclosing table element to set background on
  nsCOMPtr<nsIDOMElement> element;
  PRInt32 selectedCount;
  nsAutoString tagName;
  nsresult res = GetSelectedOrParentTableElement(*getter_AddRefs(element), tagName, selectedCount);
  if (NS_FAILED(res)) return res;

  PRBool setColor = (aColor.Length() > 0);

  if (element)
  {
    if (selectedCount > 0)
    {
      // Traverse all selected cells
      nsCOMPtr<nsIDOMElement> cell;
      res = GetFirstSelectedCell(getter_AddRefs(cell), nsnull);
      if (NS_SUCCEEDED(res) && cell)
      {
        while(cell)
        {
          if (setColor)
            res = SetAttribute(cell, NS_ConvertASCIItoUCS2("bgcolor"), aColor);
          else
            res = RemoveAttribute(cell, NS_ConvertASCIItoUCS2("bgcolor"));
          if (NS_FAILED(res)) break;

          GetNextSelectedCell(getter_AddRefs(cell), nsnull);
        };
        return res;
      }
    }
    // 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
    res = nsEditor::GetRootElement(getter_AddRefs(element));
    if (NS_FAILED(res)) return res;
    if (!element)       return NS_ERROR_NULL_POINTER;
  }
  // Use the editor method that goes through the transaction system
  if (setColor)
    res = SetAttribute(element, NS_ConvertASCIItoUCS2("bgcolor"), aColor);
  else
    res = RemoveAttribute(element, NS_ConvertASCIItoUCS2("bgcolor"));

  return res;
}

NS_IMETHODIMP nsHTMLEditor::SetBodyAttribute(const nsString& aAttribute, const nsString& aValue)
{
  nsresult res;
  // TODO: Check selection for Cell, Row, Column or table and do color on appropriate level

  NS_ASSERTION(mDocWeak, "Missing Editor DOM Document");
  
  // Set the background color attribute on the body tag
  nsCOMPtr<nsIDOMElement> bodyElement;

  res = nsEditor::GetRootElement(getter_AddRefs(bodyElement));
  if (!bodyElement) res = NS_ERROR_NULL_POINTER;
  if (NS_SUCCEEDED(res))
  {
    // Use the editor method that goes through the transaction system
    res = SetAttribute(bodyElement, aAttribute, aValue);
  }
  return res;
}

#ifdef XP_MAC
#pragma mark -
#pragma mark  nsIEditorStyleSheets methods 
#pragma mark -
#endif


NS_IMETHODIMP
nsHTMLEditor::AddStyleSheet(nsICSSStyleSheet* aSheet)
{
  AddStyleSheetTxn* txn;
  nsresult rv = CreateTxnForAddStyleSheet(aSheet, &txn);
  if (!txn) rv = NS_ERROR_NULL_POINTER;
  if (NS_SUCCEEDED(rv))
  {
    rv = Do(txn);
    if (NS_SUCCEEDED(rv))
    {
      mLastStyleSheet = do_QueryInterface(aSheet);    // save it so we can remove before applying the next one
    }
  }
  // The transaction system (if any) has taken ownwership of txns
  NS_IF_RELEASE(txn);
  
  return rv;
}


NS_IMETHODIMP
nsHTMLEditor::RemoveStyleSheet(nsICSSStyleSheet* aSheet)
{
  RemoveStyleSheetTxn* txn;
  nsresult rv = CreateTxnForRemoveStyleSheet(aSheet, &txn);
  if (!txn) rv = NS_ERROR_NULL_POINTER;
  if (NS_SUCCEEDED(rv))
  {
    rv = Do(txn);
    if (NS_SUCCEEDED(rv))
    {
      mLastStyleSheet = nsnull;        // forget it
    }
  }
  // The transaction system (if any) has taken ownwership of txns
  NS_IF_RELEASE(txn);
  
  return rv;
}

// Do NOT use transaction system for override style sheets
NS_IMETHODIMP
nsHTMLEditor::RemoveOverrideStyleSheet(nsICSSStyleSheet* aSheet)
{
  if (!mPresShellWeak) return NS_ERROR_NOT_INITIALIZED;
  nsCOMPtr<nsIPresShell> ps = do_QueryReferent(mPresShellWeak);
  if (!ps) return NS_ERROR_NOT_INITIALIZED;

  nsCOMPtr<nsIDocument> document;
  nsresult rv = ps->GetDocument(getter_AddRefs(document));
  if (NS_FAILED(rv)) return rv;
  if (!document)     return NS_ERROR_NULL_POINTER;

  nsCOMPtr<nsIStyleSet> styleSet;
  rv = ps->GetStyleSet(getter_AddRefs(styleSet));

  if (NS_FAILED(rv)) return rv;
  if (!styleSet) return NS_ERROR_NULL_POINTER;
  nsCOMPtr<nsIStyleSheet> styleSheet = do_QueryInterface(aSheet);
  if (!styleSheet) return NS_ERROR_NULL_POINTER;
  styleSet->RemoveOverrideStyleSheet(styleSheet);

  // This notifies document observers to rebuild all frames
  // (this doesn't affect style sheet because it is not a doc sheet)
  document->SetStyleSheetDisabledState(styleSheet, PR_FALSE);

  return NS_OK;
}

NS_IMETHODIMP 
nsHTMLEditor::ApplyOverrideStyleSheet(const nsString& aURL, nsICSSStyleSheet **aStyleSheet)
{
  return ApplyDocumentOrOverrideStyleSheet(aURL, PR_TRUE, aStyleSheet);
}

NS_IMETHODIMP 
nsHTMLEditor::ApplyStyleSheet(const nsString& aURL, nsICSSStyleSheet **aStyleSheet)
{
  return ApplyDocumentOrOverrideStyleSheet(aURL, PR_FALSE, aStyleSheet);
}

//Note: Loading a document style sheet is undoable, loading an override sheet is not
nsresult 
nsHTMLEditor::ApplyDocumentOrOverrideStyleSheet(const nsString& aURL, PRBool aOverride, nsICSSStyleSheet **aStyleSheet)
{
  nsresult rv   = NS_OK;
  nsCOMPtr<nsIURI> uaURL;

  rv = NS_NewURI(getter_AddRefs(uaURL), aURL);

  if (NS_SUCCEEDED(rv)) {
    nsCOMPtr<nsIDocument> document;

    if (!mPresShellWeak) return NS_ERROR_NOT_INITIALIZED;
    nsCOMPtr<nsIPresShell> ps = do_QueryReferent(mPresShellWeak);
    if (!ps) return NS_ERROR_NOT_INITIALIZED;
    rv = ps->GetDocument(getter_AddRefs(document));
    if (NS_FAILED(rv)) return rv;
    if (!document)     return NS_ERROR_NULL_POINTER;

    nsCOMPtr<nsIHTMLContentContainer> container = do_QueryInterface(document);
    if (!container) return NS_ERROR_NULL_POINTER;
      
    nsCOMPtr<nsICSSLoader> cssLoader;
    nsCOMPtr<nsICSSStyleSheet> cssStyleSheet;

    rv = container->GetCSSLoader(*getter_AddRefs(cssLoader));
    if (NS_FAILED(rv)) return rv;
    if (!cssLoader)    return NS_ERROR_NULL_POINTER;

    PRBool complete;

    if (aOverride)
    {
      // We use null for the callback and data pointer because
      //  we MUST ONLY load synchronous local files (no @import)
      rv = cssLoader->LoadAgentSheet(uaURL, *getter_AddRefs(cssStyleSheet), complete,
                                     nsnull);

      // Synchronous loads should ALWAYS return completed
      if (!complete || !cssStyleSheet)
        return NS_ERROR_NULL_POINTER;

      nsCOMPtr<nsIStyleSheet> styleSheet;
      styleSheet = do_QueryInterface(cssStyleSheet);
      nsCOMPtr<nsIStyleSet> styleSet;
      rv = ps->GetStyleSet(getter_AddRefs(styleSet));
      if (NS_FAILED(rv)) return rv;
      if (!styleSet)     return NS_ERROR_NULL_POINTER;

      // Add the override style sheet
      // (This checks if already exists)
      styleSet->AppendOverrideStyleSheet(styleSheet);
      // Save doc pointer to be able to use nsIStyleSheet::SetEnabled()
      styleSheet->SetOwningDocument(document);

      // This notifies document observers to rebuild all frames
      // (this doesn't affect style sheet because it is not a doc sheet)
      document->SetStyleSheetDisabledState(styleSheet, PR_FALSE);
    }
    else 
    {
      rv = cssLoader->LoadAgentSheet(uaURL, *getter_AddRefs(cssStyleSheet), complete,
                                     this);
      if (NS_FAILED(rv)) return rv;
      if (complete)
        ApplyStyleSheetToPresShellDocument(cssStyleSheet,this);

      //
      // If not complete, we will be notified later
      // with a call to ApplyStyleSheetToPresShellDocument().
      //
    }
    if (aStyleSheet)
    {
      *aStyleSheet = cssStyleSheet;
      NS_ADDREF(*aStyleSheet);
    }
  }
  return rv;
}

#ifdef XP_MAC
#pragma mark -
#pragma mark  nsIEditorMailSupport methods 
#pragma mark -
#endif

NS_IMETHODIMP
nsHTMLEditor::GetEmbeddedObjects(nsISupportsArray** aNodeList)
{
  if (!aNodeList)
    return NS_ERROR_NULL_POINTER;

  nsresult res;

  res = NS_NewISupportsArray(aNodeList);
  if (NS_FAILED(res)) return res;
  if (!*aNodeList) return NS_ERROR_NULL_POINTER;

  nsCOMPtr<nsIContentIterator> iter;
  res = nsComponentManager::CreateInstance(kCContentIteratorCID, nsnull,
                                           NS_GET_IID(nsIContentIterator), 
                                           getter_AddRefs(iter));
  if (!iter) return NS_ERROR_NULL_POINTER;
  if ((NS_SUCCEEDED(res)))
  {
    // get the root content
    nsCOMPtr<nsIContent> rootContent;

    nsCOMPtr<nsIDOMDocument> domdoc;
    nsEditor::GetDocument(getter_AddRefs(domdoc));
    if (!domdoc)
      return NS_ERROR_UNEXPECTED;

    nsCOMPtr<nsIDocument> doc (do_QueryInterface(domdoc));
    if (!doc)
      return NS_ERROR_UNEXPECTED;

    rootContent = doc->GetRootContent();

    iter->Init(rootContent);

    // loop through the content iterator for each content node
    while (NS_ENUMERATOR_FALSE == iter->IsDone())
    {
      nsCOMPtr<nsIContent> content;
      res = iter->CurrentNode(getter_AddRefs(content));
      if (NS_FAILED(res))
        break;
      nsCOMPtr<nsIDOMNode> node (do_QueryInterface(content));
      if (node)
      {
        nsAutoString tagName;
        node->GetNodeName(tagName);
        tagName.ToLowerCase();

        // See if it's an image or an embed
        if (tagName.EqualsWithConversion("img") || tagName.EqualsWithConversion("embed"))
          (*aNodeList)->AppendElement(node);
        else if (tagName.EqualsWithConversion("a"))
        {
          // XXX Only include links if they're links to file: URLs
          nsCOMPtr<nsIDOMHTMLAnchorElement> anchor (do_QueryInterface(content));
          if (anchor)
          {
            nsAutoString href;
            if (NS_SUCCEEDED(anchor->GetHref(href)))
              if (href.CompareWithConversion("file:", PR_TRUE, 5) == 0)
                (*aNodeList)->AppendElement(node);
          }
        }
      }
      iter->Next();
    }
  }

  return res;
}


#ifdef XP_MAC
#pragma mark -
#pragma mark  nsIEditor overrides 
#pragma mark -
#endif

// Undo, Redo, Cut, CanCut, Copy, CanCopy, all inherited from nsPlaintextEditor

static nsresult SetSelectionAroundHeadChildren(nsCOMPtr<nsISelection> aSelection, nsWeakPtr aDocWeak)
{
  nsresult res = NS_OK;
  // Set selection around <head> node
  nsCOMPtr<nsIDOMNodeList>nodeList; 
  nsAutoString headTag; headTag.AssignWithConversion("head"); 

  nsCOMPtr<nsIDOMDocument> doc = do_QueryReferent(aDocWeak);
  if (!doc) return NS_ERROR_NOT_INITIALIZED;
  res = doc->GetElementsByTagName(headTag, getter_AddRefs(nodeList));
  if (NS_FAILED(res)) return res;
  if (!nodeList) return NS_ERROR_NULL_POINTER;

  PRUint32 count; 
  nodeList->GetLength(&count);
  if (count < 1) return NS_ERROR_FAILURE;

  nsCOMPtr<nsIDOMNode> headNode;
  res = nodeList->Item(0, getter_AddRefs(headNode)); 
  if (NS_FAILED(res)) return res;
  if (!headNode) return NS_ERROR_NULL_POINTER;

  // Collapse selection to before first child of the head,
  res = aSelection->Collapse(headNode, 0);
  if (NS_FAILED(res)) return res;

  //  then extend it to just after
  nsCOMPtr<nsIDOMNodeList> childNodes;
  res = headNode->GetChildNodes(getter_AddRefs(childNodes));
  if (NS_FAILED(res)) return res;
  if (!childNodes) return NS_ERROR_NULL_POINTER;
  PRUint32 childCount;
  childNodes->GetLength(&childCount);

  return aSelection->Extend(headNode, childCount+1);
}

NS_IMETHODIMP
nsHTMLEditor::GetHeadContentsAsHTML(nsString& aOutputString)
{
  nsCOMPtr<nsISelection> selection;
  nsresult res = GetSelection(getter_AddRefs(selection));
  if (NS_FAILED(res)) return res;
  if (!selection) return NS_ERROR_NULL_POINTER;

  // Save current selection
  nsAutoSelectionReset selectionResetter(selection, this);

  res = SetSelectionAroundHeadChildren(selection, mDocWeak);
  if (NS_FAILED(res)) return res;

  res = OutputToString(aOutputString, NS_ConvertASCIItoUCS2("text/html"),
                       nsIDocumentEncoder::OutputSelectionOnly);
  if (NS_SUCCEEDED(res))
  {
    // Selection always includes <body></body>,
    //  so terminate there
    PRInt32 offset = aOutputString.Find(NS_ConvertASCIItoUCS2("<body"), PR_TRUE);
    if (offset > 0)
    {
      // Ensure the string ends in a newline
      PRUnichar newline ('\n');
      if (aOutputString.CharAt(offset-1) != newline)
        aOutputString.SetCharAt(newline, offset++);

      aOutputString.Truncate(offset);
    }
  }
  return res;
}

NS_IMETHODIMP
nsHTMLEditor::DebugUnitTests(PRInt32 *outNumTests, PRInt32 *outNumTestsFailed)
{
#ifdef DEBUG
  if (!outNumTests || !outNumTestsFailed)
    return NS_ERROR_NULL_POINTER;

  TextEditorTest *tester = new TextEditorTest();
  if (!tester)
    return NS_ERROR_OUT_OF_MEMORY;
   
  tester->Run(this, outNumTests, outNumTestsFailed);
  delete tester;
  return NS_OK;
#else
  return NS_ERROR_NOT_IMPLEMENTED;
#endif
}

#ifdef XP_MAC
#pragma mark -
#pragma mark  nsIEditorIMESupport overrides 
#pragma mark -
#endif

NS_IMETHODIMP
nsHTMLEditor::SetCompositionString(const nsString& aCompositionString, nsIPrivateTextRangeList* aTextRangeList,nsTextEventReply* aReply)
{
  NS_ASSERTION(aTextRangeList, "null ptr");
  if(nsnull == aTextRangeList)
        return NS_ERROR_NULL_POINTER;
  nsCOMPtr<nsICaret>  caretP;
  
  // workaround for windows ime bug 23558: we get every ime event twice. 
  // for escape keypress, this causes an empty string to be passed
  // twice, which freaks out the editor.  This is to detect and aviod that
  // situation:
  if (aCompositionString.IsEmpty() && !mIMETextNode) 
  {
    return NS_OK;
  }
  
  nsCOMPtr<nsISelection> selection;
  nsresult result = GetSelection(getter_AddRefs(selection));
  if (NS_FAILED(result)) return result;

  mIMETextRangeList = aTextRangeList;
  nsAutoPlaceHolderBatch batch(this, gIMETxnName);

  result = InsertText(aCompositionString.GetUnicode());

  mIMEBufferLength = aCompositionString.Length();

  if (!mPresShellWeak) return NS_ERROR_NOT_INITIALIZED;
  nsCOMPtr<nsIPresShell> ps = do_QueryReferent(mPresShellWeak);
  if (!ps) return NS_ERROR_NOT_INITIALIZED;
  ps->GetCaret(getter_AddRefs(caretP));
  caretP->SetCaretDOMSelection(selection);
  result = caretP->GetCaretCoordinates(nsICaret::eTopLevelWindowCoordinates, selection,
              &(aReply->mCursorPosition), &(aReply->mCursorIsCollapsed));

  // second part of 23558 fix:
  if (aCompositionString.IsEmpty()) 
  {
    mIMETextNode = nsnull;
  }
  
  return result;
}

NS_IMETHODIMP 
nsHTMLEditor::GetReconversionString(nsReconversionEventReply* aReply)
{
  nsresult res;

  nsCOMPtr<nsISelection> selection;
  res = GetSelection(getter_AddRefs(selection));
  if (NS_FAILED(res) || !selection)
    return (res == NS_OK) ? NS_ERROR_FAILURE : res;

  // get the first range in the selection.  Since it is
  // unclear what to do if reconversion happens with a 
  // multirange selection, we will ignore any additional ranges.
  
  nsCOMPtr<nsIDOMRange> range;
  res = selection->GetRangeAt(0, getter_AddRefs(range));
  if (NS_FAILED(res) || !range)
    return (res == NS_OK) ? NS_ERROR_FAILURE : res;
  
  nsAutoString textValue;
  res = range->ToString(textValue);
  if (NS_FAILED(res))
    return res;
  
  aReply->mReconversionString = (PRUnichar*) nsMemory::Clone(textValue.GetUnicode(),
                                                                (textValue.Length() + 1) * sizeof(PRUnichar));
  if (!aReply->mReconversionString)
    return NS_ERROR_OUT_OF_MEMORY;

  // delete the selection
  res = DeleteSelection(eNone);
  
  return res;
}

#ifdef XP_MAC
#pragma mark -
#pragma mark  StyleSheet utils 
#pragma mark -
#endif


NS_IMETHODIMP
nsHTMLEditor::ReplaceStyleSheet(nsICSSStyleSheet *aNewSheet)
{
  nsresult  rv = NS_OK;
  
  nsAutoEditBatch batchIt(this);

  if (mLastStyleSheet)
  {
    rv = RemoveStyleSheet(mLastStyleSheet);
    //XXX: rv is ignored here, why?
  }

  rv = AddStyleSheet(aNewSheet);
  
  return rv;
}

NS_IMETHODIMP 
nsHTMLEditor::StyleSheetLoaded(nsICSSStyleSheet*aSheet, PRBool aNotify)
{
  ApplyStyleSheetToPresShellDocument(aSheet, this);
  return NS_OK;
}

/* static callback */
void nsHTMLEditor::ApplyStyleSheetToPresShellDocument(nsICSSStyleSheet* aSheet, void *aData)
{
  nsresult rv = NS_OK;

  nsHTMLEditor *editor = NS_STATIC_CAST(nsHTMLEditor*, aData);
  if (editor)
  {
    rv = editor->ReplaceStyleSheet(aSheet);
  }
  // XXX: we lose the return value here. Set a flag in the editor?
}


#ifdef XP_MAC
#pragma mark -
#pragma mark  nsEditor overrides 
#pragma mark -
#endif


/** All editor operations which alter the doc should be prefaced
 *  with a call to StartOperation, naming the action and direction */
NS_IMETHODIMP
nsHTMLEditor::StartOperation(PRInt32 opID, nsIEditor::EDirection aDirection)
{
  nsEditor::StartOperation(opID, aDirection);  // will set mAction, mDirection
  if (! ((mAction==kOpInsertText) || (mAction==kOpInsertIMEText)) )
    ClearInlineStylesCache();
  if (mRules) return mRules->BeforeEdit(mAction, mDirection);
  return NS_OK;
}


/** All editor operations which alter the doc should be followed
 *  with a call to EndOperation */
NS_IMETHODIMP
nsHTMLEditor::EndOperation()
{
  // post processing
  if (! ((mAction==kOpInsertText) || (mAction==kOpInsertIMEText) || (mAction==kOpIgnore)) )
    ClearInlineStylesCache();
  nsresult res = NS_OK;
  if (mRules) res = mRules->AfterEdit(mAction, mDirection);
  nsEditor::EndOperation();  // will clear mAction, mDirection
  return res;
}  


PRBool 
nsHTMLEditor::TagCanContainTag(const nsString &aParentTag, const nsString &aChildTag)
{
  // COtherDTD gives some unwanted results.  We override them here.
  nsAutoString olStr, ulStr, liStr;
  olStr = NS_LITERAL_STRING("ol");
  ulStr = NS_LITERAL_STRING("ul");
  liStr = NS_LITERAL_STRING("li");
  
  if ( aParentTag.EqualsIgnoreCase(olStr) ||
       aParentTag.EqualsIgnoreCase(ulStr) )
  {
    // if parent is a list and tag is also a list, say "yes".
    // This is because the editor does sublists illegally for now. 
    if (aChildTag.EqualsIgnoreCase(olStr) ||
        aChildTag.EqualsIgnoreCase(ulStr) ) 
      return PR_TRUE;
  }

  if ( aParentTag.EqualsIgnoreCase(liStr) )
  {
    // list items cant contain list items
    if (aChildTag.EqualsIgnoreCase(liStr) ) 
      return PR_FALSE;
  }

/*  
  // if parent is a pre, and child is not inline, say "no"
  if ( aParentTag.EqualsWithConversion("pre") )
  {
    if (aChildTag.EqualsWithConversion("__moz_text"))
      return PR_TRUE;
    PRInt32 childTagEnum, parentTagEnum;
    nsAutoString non_const_childTag(aChildTag);
    nsAutoString non_const_parentTag(aParentTag);
    nsresult res = mDTD->StringTagToIntTag(non_const_childTag,&childTagEnum);
    if (NS_FAILED(res)) return PR_FALSE;
    res = mDTD->StringTagToIntTag(non_const_parentTag,&parentTagEnum);
    if (NS_FAILED(res)) return PR_FALSE;
    if (!mDTD->IsInlineElement(childTagEnum,parentTagEnum))
      return PR_FALSE;
  }
*/
  // else fall thru
  return nsEditor::TagCanContainTag(aParentTag, aChildTag);
}


NS_IMETHODIMP 
nsHTMLEditor::SelectEntireDocument(nsISelection *aSelection)
{
  nsresult res;
  if (!aSelection || !mRules) { return NS_ERROR_NULL_POINTER; }
  
  // get body node
  nsCOMPtr<nsIDOMElement>bodyElement;
  res = GetRootElement(getter_AddRefs(bodyElement));
  if (NS_FAILED(res)) return res;
  nsCOMPtr<nsIDOMNode>bodyNode = do_QueryInterface(bodyElement);
  if (!bodyNode) return NS_ERROR_FAILURE;
  
  // is doc empty?
  PRBool bDocIsEmpty;
  res = mRules->DocumentIsEmpty(&bDocIsEmpty);
  if (NS_FAILED(res)) return res;
    
  if (bDocIsEmpty)
  {
    // if its empty dont select entire doc - that would select the bogus node
    return aSelection->Collapse(bodyNode, 0);
  }
  else
  {
    return nsEditor::SelectEntireDocument(aSelection);
  }
  return res;
}



#ifdef XP_MAC
#pragma mark -
#pragma mark  Random methods 
#pragma mark -
#endif


NS_IMETHODIMP nsHTMLEditor::GetLayoutObject(nsIDOMNode *aNode, nsISupports **aLayoutObject)
{
  nsresult result = NS_ERROR_FAILURE;  // we return an error unless we get the index
  if (!mPresShellWeak) return NS_ERROR_NOT_INITIALIZED;
  nsCOMPtr<nsIPresShell> ps = do_QueryReferent(mPresShellWeak);
  if (!ps) return NS_ERROR_NOT_INITIALIZED;

  if ((nsnull!=aNode))
  { // get the content interface
    nsCOMPtr<nsIContent> nodeAsContent( do_QueryInterface(aNode) );
    if (nodeAsContent)
    { // get the frame from the content interface
      //Note: frames are not ref counted, so don't use an nsCOMPtr
      *aLayoutObject = nsnull;
      result = ps->GetLayoutObjectFor(nodeAsContent, aLayoutObject);
    }
  }
  else {
    result = NS_ERROR_NULL_POINTER;
  }

  return result;
}


// this will NOT find aAttribute unless aAttribute has a non-null value
// so singleton attributes like <Table border> will not be matched!
void nsHTMLEditor::IsTextPropertySetByContent(nsIDOMNode     *aNode,
                                              nsIAtom        *aProperty, 
                                              const nsString *aAttribute, 
                                              const nsString *aValue, 
                                              PRBool         &aIsSet,
                                              nsIDOMNode    **aStyleNode,
                                              nsString       *outValue) const
{
  nsresult result;
  aIsSet = PR_FALSE;  // must be initialized to false for code below to work
  nsAutoString propName;
  aProperty->ToString(propName);
  nsCOMPtr<nsIDOMNode>node = aNode;

  while (node)
  {
    nsCOMPtr<nsIDOMElement>element;
    element = do_QueryInterface(node);
    if (element)
    {
      nsAutoString tag, value;
      element->GetTagName(tag);
      if (propName.EqualsIgnoreCase(tag))
      {
        PRBool found = PR_FALSE;
        if (aAttribute && 0!=aAttribute->Length())
        {
          element->GetAttribute(*aAttribute, value);
          if (outValue) *outValue = value;
          if (value.Length())
          {
            if (!aValue) {
              found = PR_TRUE;
            }
            else if (aValue->EqualsIgnoreCase(value)) {
              found = PR_TRUE;
            }
            else {  // we found the prop with the attribute, but the value doesn't match
              break;
            }
          }
        }
        else { 
          found = PR_TRUE;
        }
        if (found)
        {
          aIsSet = PR_TRUE;
          break;
        }
      }
    }
    nsCOMPtr<nsIDOMNode>temp;
    result = node->GetParentNode(getter_AddRefs(temp));
    if (NS_SUCCEEDED(result) && temp) {
      node = do_QueryInterface(temp);
    }
    else {
      node = do_QueryInterface(nsnull);
    }
  }
}

void nsHTMLEditor::IsTextStyleSet(nsIStyleContext *aSC, 
                                  nsIAtom *aProperty, 
                                  const nsString *aAttribute,  
                                  PRBool &aIsSet) const
{
  aIsSet = PR_FALSE;
  if (aSC && aProperty)
  {
    nsStyleFont* font = (nsStyleFont*)aSC->GetStyleData(eStyleStruct_Font);
    if (nsIEditProperty::i==aProperty)
    {
      aIsSet = PRBool(font->mFont.style & NS_FONT_STYLE_ITALIC);
    }
    else if (nsIEditProperty::b==aProperty)
    { // XXX: check this logic with Peter
      aIsSet = PRBool(font->mFont.weight > NS_FONT_WEIGHT_NORMAL);
    }
  }
}


#ifdef XP_MAC
#pragma mark -
#endif

//================================================================
// HTML Editor methods
//
// Note: Table Editing methods are implemented in nsTableEditor.cpp
//


PRBool nsHTMLEditor::IsElementInBody(nsIDOMElement* aElement)
{
  return nsHTMLEditUtils::InBody(aElement, this);
}

PRBool
nsHTMLEditor::SetCaretInTableCell(nsIDOMElement* aElement)
{
  PRBool caretIsSet = PR_FALSE;

  if (aElement && IsElementInBody(aElement))
  {
    nsresult res = NS_OK;
    nsCOMPtr<nsIContent> content = do_QueryInterface(aElement);
    if (content)
    {
      nsCOMPtr<nsIAtom> atom;
      content->GetTag(*getter_AddRefs(atom));
      if (atom.get() == nsIEditProperty::table ||
          atom.get() == nsIEditProperty::tbody ||
          atom.get() == nsIEditProperty::thead ||
          atom.get() == nsIEditProperty::tfoot ||
          atom.get() == nsIEditProperty::caption ||
          atom.get() == nsIEditProperty::tr ||
          atom.get() == nsIEditProperty::td )
      {
        nsCOMPtr<nsIDOMNode> node = do_QueryInterface(aElement);
        nsCOMPtr<nsIDOMNode> parent;
        // This MUST succeed if IsElementInBody was TRUE
        node->GetParentNode(getter_AddRefs(parent));
        nsCOMPtr<nsIDOMNode>firstChild;
        // Find deepest child
        PRBool hasChild;
        while (NS_SUCCEEDED(node->HasChildNodes(&hasChild)) && hasChild)
        {
          if (NS_SUCCEEDED(node->GetFirstChild(getter_AddRefs(firstChild))))
          {
            parent = node;
            node = firstChild;
          }
        }
        // Set selection at beginning of deepest node
        nsCOMPtr<nsISelection> selection;
        res = GetSelection(getter_AddRefs(selection));
        if (NS_SUCCEEDED(res) && selection && firstChild)
        {
          res = selection->Collapse(firstChild, 0);
          if (NS_SUCCEEDED(res))
            caretIsSet = PR_TRUE;
        }
      }
    }
  }
  return caretIsSet;
}            



NS_IMETHODIMP
nsHTMLEditor::IsRootTag(nsString &aTag, PRBool &aIsTag)
{
  static char bodyTag[] = "body";
  static char tdTag[] = "td";
  static char thTag[] = "th";
  static char captionTag[] = "caption";
  if (aTag.EqualsIgnoreCase(bodyTag) ||
      aTag.EqualsIgnoreCase(tdTag) ||
      aTag.EqualsIgnoreCase(thTag) ||
      aTag.EqualsIgnoreCase(captionTag) )
  {
    aIsTag = PR_TRUE;
  }
  else {
    aIsTag = PR_FALSE;
  }
  return NS_OK;
}

NS_IMETHODIMP
nsHTMLEditor::IsSubordinateBlock(nsString &aTag, PRBool &aIsTag)
{
  static char p[] = "p";
  static char h1[] = "h1";
  static char h2[] = "h2";
  static char h3[] = "h3";
  static char h4[] = "h4";
  static char h5[] = "h5";
  static char h6[] = "h6";
  static char address[] = "address";
  static char pre[] = "pre";
  static char li[] = "li";
  static char dt[] = "dt";
  static char dd[] = "dd";
  if (aTag.EqualsIgnoreCase(p)  ||
      aTag.EqualsIgnoreCase(h1) ||
      aTag.EqualsIgnoreCase(h2) ||
      aTag.EqualsIgnoreCase(h3) ||
      aTag.EqualsIgnoreCase(h4) ||
      aTag.EqualsIgnoreCase(h5) ||
      aTag.EqualsIgnoreCase(h6) ||
      aTag.EqualsIgnoreCase(address) ||
      aTag.EqualsIgnoreCase(pre) ||
      aTag.EqualsIgnoreCase(li) ||
      aTag.EqualsIgnoreCase(dt) ||
      aTag.EqualsIgnoreCase(dd) )
  {
    aIsTag = PR_TRUE;
  }
  else {
    aIsTag = PR_FALSE;
  }
  return NS_OK;
}



///////////////////////////////////////////////////////////////////////////
// GetEnclosingTable: find ancestor who is a table, if any
//                  
nsCOMPtr<nsIDOMNode> 
nsHTMLEditor::GetEnclosingTable(nsIDOMNode *aNode)
{
  NS_PRECONDITION(aNode, "null node passed to nsHTMLEditor::GetEnclosingTable");
  nsCOMPtr<nsIDOMNode> tbl, tmp, node = aNode;

  while (!tbl)
  {
    tmp = GetBlockNodeParent(node);
    if (!tmp) break;
    if (nsHTMLEditUtils::IsTable(tmp)) tbl = tmp;
    node = tmp;
  }
  return tbl;
}

#ifdef XP_MAC
#pragma mark -
#endif

void nsHTMLEditor::CacheInlineStyles(nsIDOMNode *aNode)
{
  if (!aNode) return;
  nsCOMPtr<nsIDOMNode> resultNode;
  mCachedNode = do_QueryInterface(aNode);
  IsTextPropertySetByContent(aNode, mBoldAtom, 0, 0, mCachedBoldStyle, getter_AddRefs(resultNode));
  IsTextPropertySetByContent(aNode, mItalicAtom, 0, 0, mCachedItalicStyle, getter_AddRefs(resultNode));
  IsTextPropertySetByContent(aNode, mUnderlineAtom, 0, 0, mCachedUnderlineStyle, getter_AddRefs(resultNode));
  
}

void nsHTMLEditor::ClearInlineStylesCache()
{
  mCachedNode = nsnull;
}

#ifdef PRE_NODE_IN_BODY
nsCOMPtr<nsIDOMElement> nsHTMLEditor::FindPreElement()
{
  nsCOMPtr<nsIDOMDocument> domdoc;
  nsEditor::GetDocument(getter_AddRefs(domdoc));
  if (!domdoc)
    return 0;

  nsCOMPtr<nsIDocument> doc (do_QueryInterface(domdoc));
  if (!doc)
    return 0;

  nsIContent* rootContent = doc->GetRootContent();
  if (!rootContent)
    return 0;

  nsCOMPtr<nsIDOMNode> rootNode (do_QueryInterface(rootContent));
  if (!rootNode)
    return 0;

  nsString prestr ("PRE");  // GetFirstNodeOfType requires capitals
  nsCOMPtr<nsIDOMNode> preNode;
  if (!NS_SUCCEEDED(nsEditor::GetFirstNodeOfType(rootNode, prestr,
                                                 getter_AddRefs(preNode))))
    return 0;

  return do_QueryInterface(preNode);
}
#endif /* PRE_NODE_IN_BODY */

void nsHTMLEditor::HandleEventListenerError()
{
  if (gNoisy) { printf("failed to add event listener\n"); }
  // null out the nsCOMPtrs
  mKeyListenerP = nsnull;
  mMouseListenerP = nsnull;
  mTextListenerP = nsnull;
  mDragListenerP = nsnull;
  mCompositionListenerP = nsnull;
  mFocusListenerP = nsnull;
}

/* 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 nsEditor::JoinNodes so action is undoable. 
 * Should be called within the context of a batch transaction.
 */
NS_IMETHODIMP
nsHTMLEditor::CollapseAdjacentTextNodes(nsIDOMRange *aInRange)
{
  if (!aInRange) return NS_ERROR_NULL_POINTER;
  nsAutoTxnsConserveSelection dontSpazMySelection(this);
  nsVoidArray 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
  nsCOMPtr<nsIContentIterator> iter;
  nsresult result = nsComponentManager::CreateInstance(kSubtreeIteratorCID, nsnull,
                                              NS_GET_IID(nsIContentIterator), 
                                              getter_AddRefs(iter));
  if (NS_FAILED(result)) return result;
  if (!iter) return NS_ERROR_NULL_POINTER;

  iter->Init(aInRange);
  nsCOMPtr<nsIContent> content;
  result = iter->CurrentNode(getter_AddRefs(content));  
  if (!content) return NS_OK;
  
  while (NS_ENUMERATOR_FALSE == iter->IsDone())
  {
    nsCOMPtr<nsIDOMCharacterData> text = do_QueryInterface(content);
    nsCOMPtr<nsIDOMNode>          node = do_QueryInterface(content);
    if (text && node && IsEditable(node))
    {
      textNodes.AppendElement((void*)(node.get()));
    }
    iter->Next();
    iter->CurrentNode(getter_AddRefs(content));
  }

  // now that I have a list of text nodes, collapse adjacent text nodes
  // NOTE: assumption that JoinNodes keeps the righthand node
  nsIDOMNode *leftTextNode = (nsIDOMNode *)(textNodes.ElementAt(0));
  nsIDOMNode *rightTextNode = (nsIDOMNode *)(textNodes.ElementAt(1));

  while (leftTextNode && rightTextNode)
  {
    // get the prev sibling of the right node, and see if it's leftTextNode
    nsCOMPtr<nsIDOMNode> prevSibOfRightNode;
    result = GetPriorHTMLSibling(rightTextNode, address_of(prevSibOfRightNode));
    if (NS_FAILED(result)) return result;
    if (prevSibOfRightNode && (prevSibOfRightNode.get() == leftTextNode))
    {
      nsCOMPtr<nsIDOMNode> parent;
      result = rightTextNode->GetParentNode(getter_AddRefs(parent));
      if (NS_FAILED(result)) return result;
      if (!parent) return NS_ERROR_NULL_POINTER;
      result = JoinNodes(leftTextNode, rightTextNode, parent);
      if (NS_FAILED(result)) return result;
    }

    textNodes.RemoveElementAt(0); // remove the leftmost text node from the list
    leftTextNode = (nsIDOMNode *)(textNodes.ElementAt(0));
    rightTextNode = (nsIDOMNode *)(textNodes.ElementAt(1));
  }

  return result;
}

NS_IMETHODIMP
nsHTMLEditor::GetNextElementByTagName(nsIDOMElement    *aCurrentElement,
                                      const nsString   *aTagName,
                                      nsIDOMElement   **aReturn)
{
  nsresult res = NS_OK;
  if (!aCurrentElement || !aTagName || !aReturn)
    return NS_ERROR_NULL_POINTER;

  nsIAtom *tagAtom = NS_NewAtom(*aTagName);
  if (!tagAtom) { return NS_ERROR_NULL_POINTER; }
  if (tagAtom==nsIEditProperty::th)
    tagAtom=nsIEditProperty::td;

  nsCOMPtr<nsIDOMNode> currentNode = do_QueryInterface(aCurrentElement);
  if (!currentNode)
    return NS_ERROR_FAILURE;

  *aReturn = nsnull;

  nsCOMPtr<nsIDOMNode> nextNode;
  PRBool done = PR_FALSE;

  do {
    res = GetNextNode(currentNode, PR_TRUE, getter_AddRefs(nextNode));
    if (NS_FAILED(res)) return res;
    if (!nextNode) break;

    nsCOMPtr<nsIAtom> atom = GetTag(currentNode);

    if (tagAtom==atom.get())
    {
      nsCOMPtr<nsIDOMElement> element = do_QueryInterface(currentNode);
      if (!element) return NS_ERROR_NULL_POINTER;

      *aReturn = element;
      NS_ADDREF(*aReturn);
      done = PR_TRUE;
      return NS_OK;
    }
    currentNode = nextNode;
  } while (!done);

  return res;
}

NS_IMETHODIMP 
nsHTMLEditor::SetSelectionAtDocumentStart(nsISelection *aSelection)
{
  nsCOMPtr<nsIDOMElement> bodyElement;
  nsresult res = GetRootElement(getter_AddRefs(bodyElement));  
  if (NS_SUCCEEDED(res))
  {
  	if (!bodyElement) return NS_ERROR_NULL_POINTER;
    res = aSelection->Collapse(bodyElement,0);
  }
  return res;
}

#ifdef XP_MAC
#pragma mark -
#endif

///////////////////////////////////////////////////////////////////////////
// GetPriorHTMLSibling: returns the previous editable sibling, if there is
//                   one within the parent
//                       
nsresult
nsHTMLEditor::GetPriorHTMLSibling(nsIDOMNode *inNode, nsCOMPtr<nsIDOMNode> *outNode)
{
  if (!outNode || !inNode) return NS_ERROR_NULL_POINTER;
  nsresult res = NS_OK;
  *outNode = nsnull;
  nsCOMPtr<nsIDOMNode> temp, node = do_QueryInterface(inNode);
  
  while (1)
  {
    res = node->GetPreviousSibling(getter_AddRefs(temp));
    if (NS_FAILED(res)) return res;
    if (!temp) return NS_OK;  // return null sibling
    // if it's editable, we're done
    if (IsEditable(temp)) break;
    // otherwise try again
    node = temp;
  }
  *outNode = temp;
  return res;
}



///////////////////////////////////////////////////////////////////////////
// GetPriorHTMLSibling: returns the previous editable sibling, if there is
//                   one within the parent.  just like above routine but
//                   takes a parent/offset instead of a node.
//                       
nsresult
nsHTMLEditor::GetPriorHTMLSibling(nsIDOMNode *inParent, PRInt32 inOffset, nsCOMPtr<nsIDOMNode> *outNode)
{
  if (!outNode || !inParent) return NS_ERROR_NULL_POINTER;
  nsresult res = NS_OK;
  *outNode = nsnull;
  if (!inOffset) return NS_OK;  // return null sibling if at offset zero
  nsCOMPtr<nsIDOMNode> node = nsEditor::GetChildAt(inParent,inOffset-1);
  if (IsEditable(node)) 
  {
    *outNode = node;
    return res;
  }
  // else
  return GetPriorHTMLSibling(node, outNode);
}



///////////////////////////////////////////////////////////////////////////
// GetNextHTMLSibling: returns the next editable sibling, if there is
//                   one within the parent
//                       
nsresult
nsHTMLEditor::GetNextHTMLSibling(nsIDOMNode *inNode, nsCOMPtr<nsIDOMNode> *outNode)
{
  if (!outNode) return NS_ERROR_NULL_POINTER;
  nsresult res = NS_OK;
  *outNode = nsnull;
  nsCOMPtr<nsIDOMNode> temp, node = do_QueryInterface(inNode);
  
  while (1)
  {
    res = node->GetNextSibling(getter_AddRefs(temp));
    if (NS_FAILED(res)) return res;
    if (!temp) return NS_ERROR_FAILURE;
    // if it's editable, we're done
    if (IsEditable(temp)) break;
    // otherwise try again
    node = temp;
  }
  *outNode = temp;
  return res;
}



///////////////////////////////////////////////////////////////////////////
// GetNextHTMLSibling: returns the next editable sibling, if there is
//                   one within the parent.  just like above routine but
//                   takes a parent/offset instead of a node.
//                       
nsresult
nsHTMLEditor::GetNextHTMLSibling(nsIDOMNode *inParent, PRInt32 inOffset, nsCOMPtr<nsIDOMNode> *outNode)
{
  if (!outNode || !inParent) return NS_ERROR_NULL_POINTER;
  nsresult res = NS_OK;
  *outNode = nsnull;
  nsCOMPtr<nsIDOMNode> node = nsEditor::GetChildAt(inParent,inOffset);
  if (!node) return NS_OK; // return null sibling if no sibling
  if (IsEditable(node)) 
  {
    *outNode = node;
    return res;
  }
  // else
  return GetPriorHTMLSibling(node, outNode);
}



///////////////////////////////////////////////////////////////////////////
// GetPriorHTMLNode: returns the previous editable leaf node, if there is
//                   one within the <body>
//                       
nsresult
nsHTMLEditor::GetPriorHTMLNode(nsIDOMNode *inNode, nsCOMPtr<nsIDOMNode> *outNode)
{
  if (!outNode) return NS_ERROR_NULL_POINTER;
  nsresult res = GetPriorNode(inNode, PR_TRUE, getter_AddRefs(*outNode));
  if (NS_FAILED(res)) return res;
  
  // if it's not in the body, then zero it out
  if (*outNode && !nsHTMLEditUtils::InBody(*outNode, this))
  {
    *outNode = nsnull;
  }
  return res;
}


///////////////////////////////////////////////////////////////////////////
// GetPriorHTMLNode: same as above but takes {parent,offset} instead of node
//                       
nsresult
nsHTMLEditor::GetPriorHTMLNode(nsIDOMNode *inParent, PRInt32 inOffset, nsCOMPtr<nsIDOMNode> *outNode)
{
  if (!outNode) return NS_ERROR_NULL_POINTER;
  nsresult res = GetPriorNode(inParent, inOffset, PR_TRUE, getter_AddRefs(*outNode));
  if (NS_FAILED(res)) return res;
  
  // if it's not in the body, then zero it out
  if (*outNode && !nsHTMLEditUtils::InBody(*outNode, this))
  {
    *outNode = nsnull;
  }
  return res;
}


///////////////////////////////////////////////////////////////////////////
// GetNextHTMLNode: returns the next editable leaf node, if there is
//                   one within the <body>
//                       
nsresult
nsHTMLEditor::GetNextHTMLNode(nsIDOMNode *inNode, nsCOMPtr<nsIDOMNode> *outNode)
{
  if (!outNode) return NS_ERROR_NULL_POINTER;
  nsresult res = GetNextNode(inNode, PR_TRUE, getter_AddRefs(*outNode));
  if (NS_FAILED(res)) return res;
  
  // if it's not in the body, then zero it out
  if (*outNode && !nsHTMLEditUtils::InBody(*outNode, this))
  {
    *outNode = nsnull;
  }
  return res;
}


///////////////////////////////////////////////////////////////////////////
// GetNHTMLextNode: same as above but takes {parent,offset} instead of node
//                       
nsresult
nsHTMLEditor::GetNextHTMLNode(nsIDOMNode *inParent, PRInt32 inOffset, nsCOMPtr<nsIDOMNode> *outNode)
{
  if (!outNode) return NS_ERROR_NULL_POINTER;
  nsresult res = GetNextNode(inParent, inOffset, PR_TRUE, getter_AddRefs(*outNode));
  if (NS_FAILED(res)) return res;
  
  // if it's not in the body, then zero it out
  if (*outNode && !nsHTMLEditUtils::InBody(*outNode, this))
  {
    *outNode = nsnull;
  }
  return res;
}


nsresult 
nsHTMLEditor::IsFirstEditableChild( nsIDOMNode *aNode, PRBool *aOutIsFirst)
{
  // check parms
  if (!aOutIsFirst || !aNode) return NS_ERROR_NULL_POINTER;
  
  // init out parms
  *aOutIsFirst = PR_FALSE;
  
  // find first editable child and compare it to aNode
  nsCOMPtr<nsIDOMNode> parent, firstChild;
  nsresult res = aNode->GetParentNode(getter_AddRefs(parent));
  if (NS_FAILED(res)) return res;
  if (!parent) return NS_ERROR_FAILURE;
  res = GetFirstEditableChild(parent, address_of(firstChild));
  if (NS_FAILED(res)) return res;
  
  *aOutIsFirst = (firstChild.get() == aNode);
  return res;
}


nsresult 
nsHTMLEditor::IsLastEditableChild( nsIDOMNode *aNode, PRBool *aOutIsLast)
{
  // check parms
  if (!aOutIsLast || !aNode) return NS_ERROR_NULL_POINTER;
  
  // init out parms
  *aOutIsLast = PR_FALSE;
  
  // find last editable child and compare it to aNode
  nsCOMPtr<nsIDOMNode> parent, lastChild;
  nsresult res = aNode->GetParentNode(getter_AddRefs(parent));
  if (NS_FAILED(res)) return res;
  if (!parent) return NS_ERROR_FAILURE;
  res = GetLastEditableChild(parent, address_of(lastChild));
  if (NS_FAILED(res)) return res;
  
  *aOutIsLast = (lastChild.get() == aNode);
  return res;
}


nsresult 
nsHTMLEditor::GetFirstEditableChild( nsIDOMNode *aNode, nsCOMPtr<nsIDOMNode> *aOutFirstChild)
{
  // check parms
  if (!aOutFirstChild || !aNode) return NS_ERROR_NULL_POINTER;
  
  // init out parms
  *aOutFirstChild = nsnull;
  
  // find first editable child
  nsCOMPtr<nsIDOMNode> child;
  nsresult res = aNode->GetFirstChild(getter_AddRefs(child));
  if (NS_FAILED(res)) return res;
  
  while (child && !IsEditable(child))
  {
    nsCOMPtr<nsIDOMNode> tmp;
    res = child->GetNextSibling(getter_AddRefs(tmp));
    if (NS_FAILED(res)) return res;
    if (!tmp) return NS_ERROR_FAILURE;
    child = tmp;
  }
  
  *aOutFirstChild = child;
  return res;
}


nsresult 
nsHTMLEditor::GetLastEditableChild( nsIDOMNode *aNode, nsCOMPtr<nsIDOMNode> *aOutLastChild)
{
  // check parms
  if (!aOutLastChild || !aNode) return NS_ERROR_NULL_POINTER;
  
  // init out parms
  *aOutLastChild = nsnull;
  
  // find last editable child
  nsCOMPtr<nsIDOMNode> child;
  nsresult res = aNode->GetLastChild(getter_AddRefs(child));
  if (NS_FAILED(res)) return res;
  
  while (child && !IsEditable(child))
  {
    nsCOMPtr<nsIDOMNode> tmp;
    res = child->GetPreviousSibling(getter_AddRefs(tmp));
    if (NS_FAILED(res)) return res;
    if (!tmp) return NS_ERROR_FAILURE;
    child = tmp;
  }
  
  *aOutLastChild = child;
  return res;
}

nsresult 
nsHTMLEditor::GetFirstEditableLeaf( nsIDOMNode *aNode, nsCOMPtr<nsIDOMNode> *aOutFirstLeaf)
{
  // check parms
  if (!aOutFirstLeaf || !aNode) return NS_ERROR_NULL_POINTER;
  
  // init out parms
  *aOutFirstLeaf = nsnull;
  
  // find leftmost leaf
  nsCOMPtr<nsIDOMNode> child;
  nsresult res = GetLeftmostChild(aNode, getter_AddRefs(child));
  if (NS_FAILED(res)) return res;
  
  while (child && (!IsEditable(child) || !nsHTMLEditUtils::IsLeafNode(child)))
  {
    nsCOMPtr<nsIDOMNode> tmp;
    res = GetNextHTMLNode(child, address_of(tmp));
    if (NS_FAILED(res)) return res;
    if (!tmp) return NS_ERROR_FAILURE;
    
    // only accept nodes that are descendants of aNode
    if (nsHTMLEditUtils::IsDescendantOf(tmp, aNode))
      child = tmp;
    else
    {
      child = nsnull;  // this will abort the loop
    }
  }
  
  *aOutFirstLeaf = child;
  return res;
}


nsresult 
nsHTMLEditor::GetLastEditableLeaf( nsIDOMNode *aNode, nsCOMPtr<nsIDOMNode> *aOutLastLeaf)
{
  // check parms
  if (!aOutLastLeaf || !aNode) return NS_ERROR_NULL_POINTER;
  
  // init out parms
  *aOutLastLeaf = nsnull;
  
  // find leftmost leaf
  nsCOMPtr<nsIDOMNode> child;
  nsresult res = GetRightmostChild(aNode, getter_AddRefs(child));
  if (NS_FAILED(res)) return res;
  
  while (child && (!IsEditable(child) || !nsHTMLEditUtils::IsLeafNode(child)))
  {
    nsCOMPtr<nsIDOMNode> tmp;
    res = GetPriorHTMLNode(child, address_of(tmp));
    if (NS_FAILED(res)) return res;
    if (!tmp) return NS_ERROR_FAILURE;
    
    // only accept nodes that are descendants of aNode
    if (nsHTMLEditUtils::IsDescendantOf(tmp, aNode))
      child = tmp;
    else
    {
      child = nsnull;
    }
  }
  
  *aOutLastLeaf = child;
  return res;
}

///////////////////////////////////////////////////////////////////////////
// IsEmptyNode: figure 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
nsHTMLEditor::IsEmptyNode( nsIDOMNode *aNode, 
                           PRBool *outIsEmptyNode, 
                           PRBool aMozBRDoesntCount,
                           PRBool aListOrCellNotEmpty,
                           PRBool aSafeToAskFrames)
{
  if (!aNode || !outIsEmptyNode) return NS_ERROR_NULL_POINTER;
  *outIsEmptyNode = PR_TRUE;
  
  // effeciency hack - special case if it's a text node
  if (nsEditor::IsTextNode(aNode))
  {
    PRUint32 length = 0;
    nsCOMPtr<nsIDOMCharacterData>nodeAsText;
    nodeAsText = do_QueryInterface(aNode);
    nodeAsText->GetLength(&length);
    if (length) *outIsEmptyNode = PR_FALSE;
    return NS_OK;
  }

  // if it's not a text node (handled above) and it's not a container,
  // then we dont call it empty (it's an <hr>, or <br>, etc).
  // Also, if it's an anchor then dont 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.
  if (!IsContainer(aNode) || nsHTMLEditUtils::IsAnchor(aNode) ||
       nsHTMLEditUtils::IsTextarea(aNode) || nsHTMLEditUtils::IsMap(aNode) ||
       (aListOrCellNotEmpty && nsHTMLEditUtils::IsListItem(aNode)) ||
       (aListOrCellNotEmpty && nsHTMLEditUtils::IsTableCell(aNode)) ) 
  {
    *outIsEmptyNode = PR_FALSE;
    return NS_OK;
  }
  
  // iterate over node. if no children, or all children are either 
  // empty text nodes or non-editable, then node qualifies as empty
  nsCOMPtr<nsIContentIterator> iter;
  nsCOMPtr<nsIContent> nodeAsContent = do_QueryInterface(aNode);
  if (!nodeAsContent) return NS_ERROR_FAILURE;
  nsresult res = nsComponentManager::CreateInstance(kCContentIteratorCID,
                                        nsnull,
                                        NS_GET_IID(nsIContentIterator), 
                                        getter_AddRefs(iter));
  if (NS_FAILED(res)) return res;
  res = iter->Init(nodeAsContent);
  if (NS_FAILED(res)) return res;
    
  while (NS_ENUMERATOR_FALSE == iter->IsDone())
  {
    nsCOMPtr<nsIDOMNode> node;
    nsCOMPtr<nsIContent> content;
    res = iter->CurrentNode(getter_AddRefs(content));
    if (NS_FAILED(res)) return res;
    node = do_QueryInterface(content);
    if (!node) return NS_ERROR_FAILURE;
 
    // is the node editable and non-empty?  if so, return false
    if (nsEditor::IsEditable(node))
    {
      if (nsEditor::IsTextNode(node))
      {
        PRUint32 length = 0;
        nsCOMPtr<nsIDOMCharacterData>nodeAsText;
        nodeAsText = do_QueryInterface(node);
        nodeAsText->GetLength(&length);
        if (aSafeToAskFrames)
        {
          nsCOMPtr<nsISelectionController> selCon;
          res = GetSelectionController(getter_AddRefs(selCon));
          if (NS_FAILED(res)) return res;
          if (!selCon) return NS_ERROR_FAILURE;
          PRBool isVisible = PR_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)
          res = selCon->CheckVisibility(node, 0, length, &isVisible);
          if (NS_FAILED(res)) return res;
          if (isVisible) 
          {
            *outIsEmptyNode = PR_FALSE;
            break;
          }
        }
        else if (length)
        {
          *outIsEmptyNode = PR_FALSE;
          break;
        }
      }
      else  // an editable, non-text node. we aren't an empty block 
      {
        // is it the node we are iterating over?
        if (node.get() == aNode) break;
        // is it a moz-BR and did the caller ask us not to consider those relevant?
        if (!(aMozBRDoesntCount && nsHTMLEditUtils::IsMozBR(node))) 
        {
          // is it an empty node of some sort?
          PRBool isEmptyNode;
          res = IsEmptyNode(node, &isEmptyNode, aMozBRDoesntCount, aListOrCellNotEmpty);
          if (NS_FAILED(res)) return res;
          if (!isEmptyNode) 
          {
            // otherwise it ain't empty
            *outIsEmptyNode = PR_FALSE;
            break;
          }
        }
      }
    }
    res = iter->Next();
    if (NS_FAILED(res)) return res;
  }
  
  return NS_OK;
}