gecko-dev/docshell/base/nsDocShell.cpp

/* -*- Mode: C++; tab-width: 3; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * The contents of this file are subject to the Mozilla 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/MPL/
 * 
 * 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 the Mozilla browser.
 * 
 * The Initial Developer of the Original Code is Netscape
 * Communications, Inc.  Portions created by Netscape are
 * Copyright (C) 1999, Mozilla.  All Rights Reserved.
 * 
 * Contributor(s):
 *   Travis Bogard <travis@netscape.com>
 *   Pierre Phaneuf <pp@ludusdesign.com>
 */

#include "nsDocShell.h"
#include "nsIComponentManager.h"
#include "nsIContent.h"
#include "nsIDocument.h"
#include "nsIDOMDocument.h"
#include "nsIDOMElement.h"
#include "nsIDocumentViewer.h"
#include "nsIDeviceContext.h"
#include "nsCURILoader.h"
#include "nsLayoutCID.h"
#include "nsNetUtil.h"
#include "nsRect.h"
#include "prprf.h"
#include "nsIFrame.h"
#include "nsIMarkupDocumentViewer.h"
#include "nsXPIDLString.h"
#include "nsIChromeEventHandler.h"

#ifdef XXX_NS_DEBUG       // XXX: we'll need a logging facility for debugging
#define WEB_TRACE(_bit,_args)            \
  PR_BEGIN_MACRO                         \
    if (WEB_LOG_TEST(gLogModule,_bit)) { \
      PR_LogPrint _args;                 \
    }                                    \
  PR_END_MACRO
#else
#define WEB_TRACE(_bit,_args)
#endif




//*****************************************************************************
//***    nsDocShell: Object Management
//*****************************************************************************

nsDocShell::nsDocShell() : 
  mCreated(PR_FALSE),
  mContentListener(nsnull),
  mInitInfo(nsnull), 
  mMarginWidth(0), 
  mMarginHeight(0),
  mItemType(typeContent),
  mParent(nsnull),
  mTreeOwner(nsnull),
  mChromeEventHandler(nsnull)
{
  NS_INIT_REFCNT();
}

nsDocShell::~nsDocShell()
{
   if(mInitInfo)
      {
      delete mInitInfo;
      mInitInfo = nsnull;
      }

   if(mContentListener)
      {
      mContentListener->DocShell(nsnull);
      mContentListener->Release();
      mContentListener = nsnull;
      }
}

NS_IMETHODIMP nsDocShell::Create(nsISupports* aOuter, const nsIID& aIID, 
  void** ppv)
{
  NS_ENSURE_ARG_POINTER(ppv);
  NS_ENSURE_NO_AGGREGATION(aOuter);

  nsDocShell* docShell = new  nsDocShell();
  NS_ENSURE_TRUE(docShell, NS_ERROR_OUT_OF_MEMORY);

  NS_ADDREF(docShell);
  nsresult rv = docShell->QueryInterface(aIID, ppv);
  NS_RELEASE(docShell);  
  return rv;
}

//*****************************************************************************
// nsDocShell::nsISupports
//*****************************************************************************   

NS_IMPL_ADDREF(nsDocShell)
NS_IMPL_RELEASE(nsDocShell)

NS_INTERFACE_MAP_BEGIN(nsDocShell)
   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIDocShell)
   NS_INTERFACE_MAP_ENTRY(nsIDocShell)
   NS_INTERFACE_MAP_ENTRY(nsIDocShellTreeItem)
   NS_INTERFACE_MAP_ENTRY(nsIDocShellTreeNode)
   NS_INTERFACE_MAP_ENTRY(nsIBaseWindow)
   NS_INTERFACE_MAP_ENTRY(nsIScrollable)
   NS_INTERFACE_MAP_ENTRY(nsITextScroll)
   NS_INTERFACE_MAP_ENTRY(nsIInterfaceRequestor)
   NS_INTERFACE_MAP_ENTRY(nsIScriptGlobalObjectOwner)
NS_INTERFACE_MAP_END

//*****************************************************************************
// nsDocShell::nsIDocShell
//*****************************************************************************   

NS_IMETHODIMP nsDocShell::LoadURI(nsIURI* aUri, 
   nsIPresContext* presContext)
{
   //NS_ENSURE_ARG(aUri);  // Done in LoadURIVia for us.

   return LoadURIVia(aUri, presContext, 0);
}

NS_IMETHODIMP nsDocShell::LoadURIVia(nsIURI* aUri, 
   nsIPresContext* aPresContext, PRUint32 aAdapterBinding)
{
   NS_ENSURE_ARG(aUri);

   nsCOMPtr<nsIURILoader> uriLoader = do_CreateInstance(NS_URI_LOADER_PROGID);
   NS_ENSURE_TRUE(uriLoader, NS_ERROR_FAILURE);

   NS_ENSURE_SUCCESS(EnsureContentListener(), NS_ERROR_FAILURE);
   mContentListener->SetPresContext(aPresContext);

   NS_ENSURE_SUCCESS(uriLoader->OpenURIVia(aUri, nsIURILoader::viewNormal, nsnull, 
      NS_STATIC_CAST(nsIDocShell*, this), nsnull, mLoadCookie, 
      getter_AddRefs(mLoadCookie), aAdapterBinding), NS_ERROR_FAILURE);

   return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetDocument(nsIDOMDocument** aDocument)
{
  NS_ENSURE_ARG_POINTER(aDocument);
  NS_ENSURE_STATE(mContentViewer);

  nsCOMPtr<nsIPresShell> presShell;
  NS_ENSURE_SUCCESS(GetPresShell(getter_AddRefs(presShell)), NS_ERROR_FAILURE);

  nsCOMPtr<nsIDocument>doc;
  NS_ENSURE_SUCCESS(presShell->GetDocument(getter_AddRefs(doc)), NS_ERROR_FAILURE);
  NS_ENSURE_TRUE(doc, NS_ERROR_NULL_POINTER);

  // the result's addref comes from this QueryInterface call
  NS_ENSURE_SUCCESS(CallQueryInterface(doc.get(), aDocument), NS_ERROR_FAILURE);

  return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetCurrentURI(nsIURI** aURI)
{
   NS_ENSURE_ARG_POINTER(aURI);
   
   *aURI = mCurrentURI;
   NS_IF_ADDREF(*aURI);

   return NS_OK;
}

// SetDocument is only meaningful for doc shells that support DOM documents.  Not all do.
NS_IMETHODIMP
nsDocShell::SetDocument(nsIDOMDocument *aDOMDoc, nsIDOMElement *aRootNode)
{

   // The tricky part is bypassing the normal load process and just putting a document into
   // the webshell.  This is particularly nasty, since webshells don't normally even know
   // about their documents

   // (1) Create a document viewer 
   nsCOMPtr<nsIContentViewer> documentViewer;
   nsCOMPtr<nsIDocumentLoaderFactory> docFactory;
   static NS_DEFINE_CID(kLayoutDocumentLoaderFactoryCID, NS_LAYOUT_DOCUMENT_LOADER_FACTORY_CID);
   NS_ENSURE_SUCCESS(nsComponentManager::CreateInstance(kLayoutDocumentLoaderFactoryCID, nsnull, 
                                                       NS_GET_IID(nsIDocumentLoaderFactory),
                                                       (void**)getter_AddRefs(docFactory)),
                    NS_ERROR_FAILURE);

   nsCOMPtr<nsIDocument> doc = do_QueryInterface(aDOMDoc);
   NS_ENSURE_TRUE(doc, NS_ERROR_FAILURE);
   NS_ENSURE_SUCCESS(docFactory->CreateInstanceForDocument(NS_STATIC_CAST(nsIContentViewerContainer*, this),
                                                          doc,
                                                          "view",
                                                          getter_AddRefs(documentViewer)),
                    NS_ERROR_FAILURE); 

   // (2) Feed the docshell to the content viewer
   NS_ENSURE_SUCCESS(documentViewer->SetContainer((nsIDocShell*)this), 
      NS_ERROR_FAILURE);

   // (3) Tell the content viewer container to embed the content viewer.
   //     (This step causes everything to be set up for an initial flow.)
   NS_ENSURE_SUCCESS(Embed(documentViewer, "view", nsnull), NS_ERROR_FAILURE);

   // XXX: It would be great to get rid of this dummy channel!
   const nsAutoString uriString = "about:blank";
   nsCOMPtr<nsIURI> uri;
   NS_ENSURE_SUCCESS(NS_NewURI(getter_AddRefs(uri), uriString), NS_ERROR_FAILURE);
   NS_ENSURE_TRUE(uri, NS_ERROR_OUT_OF_MEMORY);

   nsCOMPtr<nsIChannel> dummyChannel;
   NS_ENSURE_SUCCESS(NS_OpenURI(getter_AddRefs(dummyChannel), uri, nsnull), NS_ERROR_FAILURE);

   // (4) fire start document load notification
   nsCOMPtr<nsIStreamListener> outStreamListener;
   NS_ENSURE_SUCCESS(doc->StartDocumentLoad("view", dummyChannel, nsnull, 
      NS_STATIC_CAST(nsIContentViewerContainer*, this), 
      getter_AddRefs(outStreamListener)), NS_ERROR_FAILURE);
   NS_ENSURE_SUCCESS(FireStartDocumentLoad(mDocLoader, uri, "load"), NS_ERROR_FAILURE);

   // (5) hook up the document and its content
   nsCOMPtr<nsIContent> rootContent = do_QueryInterface(aRootNode);
   NS_ENSURE_TRUE(doc, NS_ERROR_OUT_OF_MEMORY);
   NS_ENSURE_SUCCESS(rootContent->SetDocument(doc, PR_FALSE), NS_ERROR_FAILURE);
   doc->SetRootContent(rootContent);

   // (6) reflow the document
   //XXX: SetScrolling doesn't make any sense
   //SetScrolling(-1, PR_FALSE);
   PRInt32 i;
   PRInt32 ns = doc->GetNumberOfShells();
   for (i = 0; i < ns; i++) 
   {
    nsCOMPtr<nsIPresShell> shell(dont_AddRef(doc->GetShellAt(i)));
    if (shell) 
    {
      // Make shell an observer for next time
      NS_ENSURE_SUCCESS(shell->BeginObservingDocument(), NS_ERROR_FAILURE);

      // Resize-reflow this time
      nsCOMPtr<nsIDocumentViewer> docViewer = do_QueryInterface(documentViewer);
      NS_ENSURE_TRUE(docViewer, NS_ERROR_OUT_OF_MEMORY);
      nsCOMPtr<nsIPresContext> presContext;
      NS_ENSURE_SUCCESS(docViewer->GetPresContext(*(getter_AddRefs(presContext))), NS_ERROR_FAILURE);
      NS_ENSURE_TRUE(presContext, NS_ERROR_OUT_OF_MEMORY);
      float p2t;
      presContext->GetScaledPixelsToTwips(&p2t);

      nsRect r;
      NS_ENSURE_SUCCESS(GetPosition(&r.x, &r.y), NS_ERROR_FAILURE);;
      NS_ENSURE_SUCCESS(GetSize(&r.width, &r.height), NS_ERROR_FAILURE);;
      NS_ENSURE_SUCCESS(shell->InitialReflow(NSToCoordRound(r.width * p2t), NSToCoordRound(r.height * p2t)), NS_ERROR_FAILURE);

      // Now trigger a refresh
      nsCOMPtr<nsIViewManager> vm;
      NS_ENSURE_SUCCESS(shell->GetViewManager(getter_AddRefs(vm)), NS_ERROR_FAILURE);
      if (vm) 
      {
        PRBool enabled;
        documentViewer->GetEnableRendering(&enabled);
        if (enabled) {
          vm->EnableRefresh();
        }
        NS_ENSURE_SUCCESS(vm->SetWindowDimensions(NSToCoordRound(r.width * p2t), 
                                                  NSToCoordRound(r.height * p2t)), 
                          NS_ERROR_FAILURE);
      }
    }
   }

   // (7) fire end document load notification
   nsresult rv = NS_OK;
   NS_ENSURE_SUCCESS(FireEndDocumentLoad(mDocLoader, dummyChannel, rv), NS_ERROR_FAILURE);
   NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);  // test the resulting out-param separately

   return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetPresContext(nsIPresContext** aPresContext)
{
   NS_ENSURE_ARG_POINTER(aPresContext);

   if(!mContentViewer)
      {
      *aPresContext = nsnull;
      return NS_OK;
      }

   nsCOMPtr<nsIDocumentViewer> docv(do_QueryInterface(mContentViewer));
   NS_ENSURE_TRUE(docv, NS_ERROR_FAILURE);

   NS_ENSURE_SUCCESS(docv->GetPresContext(*aPresContext), NS_ERROR_FAILURE);

   return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetPresShell(nsIPresShell** aPresShell)
{
   NS_ENSURE_ARG_POINTER(aPresShell);
   
   nsCOMPtr<nsIPresContext> presContext;
   NS_ENSURE_SUCCESS(GetPresContext(getter_AddRefs(presContext)), 
      NS_ERROR_FAILURE);

   NS_ENSURE_SUCCESS(presContext->GetShell(aPresShell), NS_ERROR_FAILURE);

   return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetContentViewer(nsIContentViewer** aContentViewer)
{
   NS_ENSURE_ARG_POINTER(aContentViewer);

   *aContentViewer = mContentViewer;
   NS_IF_ADDREF(*aContentViewer);
   return NS_OK;
}

NS_IMETHODIMP nsDocShell::SetChromeEventHandler(nsIChromeEventHandler* aChromeEventHandler)
{
   // Weak reference. Don't addref.
   mChromeEventHandler = aChromeEventHandler;
   return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetChromeEventHandler(nsIChromeEventHandler** aChromeEventHandler)
{
   NS_ENSURE_ARG_POINTER(aChromeEventHandler);

   *aChromeEventHandler = mChromeEventHandler;
   NS_IF_ADDREF(*aChromeEventHandler);
   return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetParentURIContentListener(nsIURIContentListener**
   aParent)
{
   NS_ENSURE_ARG_POINTER(aParent);
   NS_ENSURE_SUCCESS(EnsureContentListener(), NS_ERROR_FAILURE);

   mContentListener->GetParentContentListener(aParent);
   return NS_OK;
}

NS_IMETHODIMP nsDocShell::SetParentURIContentListener(nsIURIContentListener*
   aParent)
{
   NS_ENSURE_SUCCESS(EnsureContentListener(), NS_ERROR_FAILURE);

   mContentListener->SetParentContentListener(aParent);
   return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetPrefs(nsIPref** aPrefs)
{
   NS_ENSURE_ARG_POINTER(aPrefs);

   *aPrefs = mPrefs;
   NS_IF_ADDREF(*aPrefs);

   return NS_OK;
}

NS_IMETHODIMP nsDocShell::SetPrefs(nsIPref* aPrefs)
{
  // null aPrefs is ok
  mPrefs = aPrefs;    // this assignment does an addref
  return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetZoom(float* zoom)
{
   NS_ENSURE_ARG_POINTER(zoom);
   NS_ENSURE_STATE(mContentViewer);

   nsCOMPtr<nsIPresContext> presContext;
   NS_ENSURE_SUCCESS(GetPresContext(getter_AddRefs(presContext)), 
      NS_ERROR_FAILURE);

   nsCOMPtr<nsIDeviceContext> deviceContext;
   NS_ENSURE_SUCCESS(presContext->GetDeviceContext(getter_AddRefs(deviceContext)),
      NS_ERROR_FAILURE);

   NS_ENSURE_SUCCESS(deviceContext->GetZoom(*zoom), NS_ERROR_FAILURE);

   return NS_OK;
}

NS_IMETHODIMP nsDocShell::SetZoom(float zoom)
{
   NS_ENSURE_STATE(mContentViewer);

   nsCOMPtr<nsIPresContext> presContext;
   NS_ENSURE_SUCCESS(GetPresContext(getter_AddRefs(presContext)), 
      NS_ERROR_FAILURE);

   nsCOMPtr<nsIDeviceContext> deviceContext;
   NS_ENSURE_SUCCESS(presContext->GetDeviceContext(getter_AddRefs(deviceContext)),
      NS_ERROR_FAILURE);

   NS_ENSURE_SUCCESS(deviceContext->SetZoom(zoom), NS_ERROR_FAILURE);

   return NS_OK;
}

NS_IMETHODIMP 
nsDocShell::GetDocLoaderObserver(nsIDocumentLoaderObserver * *aDocLoaderObserver)
{
  NS_ENSURE_ARG_POINTER(aDocLoaderObserver);

  *aDocLoaderObserver = mDocLoaderObserver;
  NS_IF_ADDREF(*aDocLoaderObserver);
  return NS_OK;
}

NS_IMETHODIMP 
nsDocShell::SetDocLoaderObserver(nsIDocumentLoaderObserver * aDocLoaderObserver)
{
  // it's legal for aDocLoaderObserver to be null.  
  mDocLoaderObserver = aDocLoaderObserver;
  return NS_OK;
}

NS_IMETHODIMP
nsDocShell::GetMarginWidth(PRInt32* aWidth)
{
  NS_ENSURE_ARG_POINTER(aWidth);

  *aWidth = mMarginWidth;
  return NS_OK;
}

NS_IMETHODIMP
nsDocShell::SetMarginWidth(PRInt32 aWidth)
{
  mMarginWidth = aWidth;
  return NS_OK;
}

NS_IMETHODIMP
nsDocShell::GetMarginHeight(PRInt32* aHeight)
{
  NS_ENSURE_ARG_POINTER(aHeight);

  *aHeight = mMarginHeight;
  return NS_OK;
}

NS_IMETHODIMP
nsDocShell::SetMarginHeight(PRInt32 aHeight)
{
  mMarginHeight = aHeight;
  return NS_OK;
}

//*****************************************************************************
// nsDocShell::nsIDocShellTreeItem
//*****************************************************************************   

NS_IMETHODIMP nsDocShell::GetName(PRUnichar** aName)
{
   NS_ENSURE_ARG_POINTER(aName);
   *aName = mName.ToNewUnicode();
   return NS_OK;
}

NS_IMETHODIMP nsDocShell::SetName(const PRUnichar* aName)
{
   mName = aName;  // this does a copy of aName
   return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetItemType(PRInt32* aItemType)
{
   NS_ENSURE_ARG_POINTER(aItemType);

   *aItemType = mItemType;
   return NS_OK;
}

NS_IMETHODIMP nsDocShell::SetItemType(PRInt32 aItemType)
{
   NS_ENSURE_ARG((aItemType == typeChrome) || (typeContent == aItemType));
   mItemType = aItemType;
   return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetParent(nsIDocShellTreeItem** aParent)
{
   NS_ENSURE_ARG_POINTER(aParent);

   *aParent = mParent;
   NS_IF_ADDREF(*aParent);

   return NS_OK;
}

NS_IMETHODIMP nsDocShell::SetParent(nsIDocShellTreeItem* aParent)
{
  // null aParent is ok
   /*
   Note this doesn't do an addref on purpose.  This is because the parent
   is an implied lifetime.  We don't want to create a cycle by refcounting
   the parent.
   */
   mParent = aParent;
  return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetSameTypeParent(nsIDocShellTreeItem** aParent)
{
   NS_ENSURE_ARG_POINTER(aParent);
   *aParent = nsnull;

   if(!mParent)
      return NS_OK;
      
   PRInt32  parentType;
   NS_ENSURE_SUCCESS(mParent->GetItemType(&parentType), NS_ERROR_FAILURE);

   if(parentType == mItemType)
      {
      *aParent = mParent;
      NS_ADDREF(*aParent);
      }
   return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetRootTreeItem(nsIDocShellTreeItem** aRootTreeItem)
{
   NS_ENSURE_ARG_POINTER(aRootTreeItem);
   *aRootTreeItem = NS_STATIC_CAST(nsIDocShellTreeItem*, this);

   nsCOMPtr<nsIDocShellTreeItem> parent;
   NS_ENSURE_SUCCESS(GetParent(getter_AddRefs(parent)), NS_ERROR_FAILURE);
   while(parent)
      {
      *aRootTreeItem = parent;
      NS_ENSURE_SUCCESS((*aRootTreeItem)->GetParent(getter_AddRefs(parent)), NS_ERROR_FAILURE);
      }
   NS_ADDREF(*aRootTreeItem);
   return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetSameTypeRootTreeItem(nsIDocShellTreeItem** aRootTreeItem)
{
   NS_ENSURE_ARG_POINTER(aRootTreeItem);
   *aRootTreeItem = NS_STATIC_CAST(nsIDocShellTreeItem*, this);

   nsCOMPtr<nsIDocShellTreeItem> parent;
   NS_ENSURE_SUCCESS(GetSameTypeParent(getter_AddRefs(parent)), NS_ERROR_FAILURE);
   while(parent)
      {
      *aRootTreeItem = parent;
      NS_ENSURE_SUCCESS((*aRootTreeItem)->GetSameTypeParent(getter_AddRefs(parent)), 
         NS_ERROR_FAILURE);
      }
   NS_ADDREF(*aRootTreeItem);
   return NS_OK;
}

NS_IMETHODIMP nsDocShell::FindItemWithName(const PRUnichar *aName, 
   nsISupports* aRequestor, nsIDocShellTreeItem **_retval)
{
   NS_ENSURE_ARG(aName);
   NS_ENSURE_ARG_POINTER(_retval);
  
   *_retval = nsnull;  // if we don't find one, we return NS_OK and a null result 
   
   // This QI may fail, but the places where we want to compare, comparing
   // against nsnull serves the same purpose.
   nsCOMPtr<nsIDocShellTreeItem> reqAsTreeItem(do_QueryInterface(aRequestor));

   // First we check our name.
   if(mName.Equals(aName))
      {
      *_retval = NS_STATIC_CAST(nsIDocShellTreeItem*, this);
      NS_ADDREF(*_retval);
      }

   // Second we check our children making sure not to ask a child if it
   // is the aRequestor.
   NS_ENSURE_SUCCESS(FindChildWithName(aName, PR_TRUE, reqAsTreeItem, _retval), 
      NS_ERROR_FAILURE);
   if(*_retval)
      return NS_OK;

   // Third if we have a parent and it isn't the requestor then we should ask
   // it to do the search.  If it is the requestor we should just stop here
   // and let the parent do the rest.
   // If we don't have a parent, then we should ask the docShellTreeOwner to do
   // the search.
   if(mParent)
      {
      if(mParent == reqAsTreeItem.get())
         return NS_OK;

      PRInt32 parentType;
      mParent->GetItemType(&parentType);
      if(parentType == mItemType)
         {
         NS_ENSURE_SUCCESS(mParent->FindItemWithName(aName,
            NS_STATIC_CAST(nsIDocShellTreeItem*, this), _retval), 
            NS_ERROR_FAILURE);
         return NS_OK;
         }
      // If the parent isn't of the same type fall through and ask tree owner.
      }

   // This QI may fail, but comparing against null serves the same purpose
   nsCOMPtr<nsIDocShellTreeOwner> reqAsTreeOwner(do_QueryInterface(aRequestor));

   if(mTreeOwner && (mTreeOwner != reqAsTreeOwner.get()))
      {
      NS_ENSURE_SUCCESS(mTreeOwner->FindItemWithName(aName, 
         NS_STATIC_CAST(nsIDocShellTreeItem*, this), _retval),
         NS_ERROR_FAILURE);
      }

  return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetTreeOwner(nsIDocShellTreeOwner** aTreeOwner)
{
   NS_ENSURE_ARG_POINTER(aTreeOwner);

   *aTreeOwner = mTreeOwner;
   NS_IF_ADDREF(*aTreeOwner);
   return NS_OK;
}

NS_IMETHODIMP nsDocShell::SetTreeOwner(nsIDocShellTreeOwner* aTreeOwner)
{
   mTreeOwner = aTreeOwner; // Weak reference per API

   PRInt32 i, n = mChildren.Count();
   for(i = 0; i < n; i++)
      {
      nsIDocShellTreeItem* child = (nsIDocShellTreeItem*) mChildren.ElementAt(i); // doesn't addref the result
      NS_ENSURE_TRUE(child, NS_ERROR_FAILURE);
      PRInt32 childType = ~mItemType; // Set it to not us in case the get fails
      child->GetItemType(&childType); // We don't care if this fails, if it does we won't set the owner
      if(childType == mItemType)
         child->SetTreeOwner(aTreeOwner);
      }

   return NS_OK;
}

//*****************************************************************************
// nsDocShell::nsIDocShellTreeNode
//*****************************************************************************   

NS_IMETHODIMP nsDocShell::GetChildCount(PRInt32 *aChildCount)
{
  NS_ENSURE_ARG_POINTER(aChildCount);
  *aChildCount = mChildren.Count();
  return NS_OK;
}

NS_IMETHODIMP nsDocShell::AddChild(nsIDocShellTreeItem *aChild)
{
   NS_ENSURE_ARG_POINTER(aChild);

   NS_ENSURE_SUCCESS(aChild->SetParent(this), NS_ERROR_FAILURE);
   mChildren.AppendElement(aChild);
   NS_ADDREF(aChild);

   PRInt32 childType = ~mItemType; // Set it to not us in case the get fails
   aChild->GetItemType(&childType);
   if(childType != mItemType)
      return NS_OK;    
   // Everything below here is only done when the child is the same type.

   aChild->SetTreeOwner(mTreeOwner);

   nsCOMPtr<nsIDocShell> childAsDocShell(do_QueryInterface(aChild));
   if(!childAsDocShell)
      return NS_OK;

   // Do some docShell Specific stuff.
   nsXPIDLString defaultCharset;
   nsXPIDLString forceCharset;
   NS_ENSURE_TRUE(mContentViewer, NS_ERROR_FAILURE);

   nsCOMPtr<nsIMarkupDocumentViewer> muDV = do_QueryInterface(mContentViewer);
   if(muDV)
      {
      NS_ENSURE_SUCCESS(muDV->GetDefaultCharacterSet(getter_Copies(defaultCharset)),
         NS_ERROR_FAILURE);
      NS_ENSURE_SUCCESS(muDV->GetForceCharacterSet(getter_Copies(forceCharset)),
         NS_ERROR_FAILURE);
      }
   nsCOMPtr<nsIContentViewer> childCV;
   NS_ENSURE_SUCCESS(childAsDocShell->GetContentViewer(getter_AddRefs(childCV)),
      NS_ERROR_FAILURE);
   if(childCV)
      {
      nsCOMPtr<nsIMarkupDocumentViewer> childmuDV = do_QueryInterface(childCV);
      if(childmuDV)
         {
         NS_ENSURE_SUCCESS(childmuDV->SetDefaultCharacterSet(defaultCharset), 
            NS_ERROR_FAILURE);
         NS_ENSURE_SUCCESS(childmuDV->SetForceCharacterSet(forceCharset), 
            NS_ERROR_FAILURE);
         }
      }

  return NS_OK;
}

NS_IMETHODIMP nsDocShell::RemoveChild(nsIDocShellTreeItem *aChild)
{
   NS_ENSURE_ARG_POINTER(aChild);

   if(mChildren.RemoveElement(aChild))
      {
      aChild->SetParent(nsnull);
      aChild->SetTreeOwner(nsnull);
      NS_RELEASE(aChild);
      }
   else
      NS_ENSURE_TRUE(PR_FALSE, NS_ERROR_INVALID_ARG);

   return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetChildAt(PRInt32 aIndex, nsIDocShellTreeItem** aChild)
{
   NS_ENSURE_ARG_POINTER(aChild);
   NS_ENSURE_ARG_RANGE(aIndex, 0, mChildren.Count() - 1);

   *aChild = (nsIDocShellTreeItem*) mChildren.ElementAt(aIndex);
   NS_IF_ADDREF(*aChild);

   return NS_OK;
}

NS_IMETHODIMP nsDocShell::FindChildWithName(const PRUnichar *aName, 
   PRBool aRecurse, nsIDocShellTreeItem* aRequestor, 
   nsIDocShellTreeItem **_retval)
{
   NS_ENSURE_ARG(aName);
   NS_ENSURE_ARG_POINTER(_retval);
  
   *_retval = nsnull;  // if we don't find one, we return NS_OK and a null result 

   nsAutoString name(aName);
   nsXPIDLString childName;
   PRInt32 i, n = mChildren.Count();
   for(i = 0; i < n; i++) 
      {
      nsIDocShellTreeItem* child = (nsIDocShellTreeItem*) mChildren.ElementAt(i); // doesn't addref the result
      NS_ENSURE_TRUE(child, NS_ERROR_FAILURE);
      child->GetName(getter_Copies(childName));
      if(name.Equals(childName))
         {
         *_retval = child;
         NS_ADDREF(*_retval);
         break;
         }

      if(aRecurse && (aRequestor != child)) // Only ask the child if it isn't the requestor
         {
         PRInt32 childType;
         child->GetItemType(&childType);

         if(childType == mItemType) //Only ask it to check children if it is same type
            {
            // See if child contains the shell with the given name
            nsCOMPtr<nsIDocShellTreeNode> childAsNode(do_QueryInterface(child));
            if(child)
               {
               NS_ENSURE_SUCCESS(childAsNode->FindChildWithName(aName, PR_TRUE,
                  NS_STATIC_CAST(nsIDocShellTreeItem*, this), _retval),
                  NS_ERROR_FAILURE);
               }
            }
         }
      if(*_retval)   // found it
         return NS_OK;
      }
   return NS_OK;
}

//*****************************************************************************
// nsDocShell::nsIBaseWindow
//*****************************************************************************   

NS_IMETHODIMP nsDocShell::InitWindow(nativeWindow parentNativeWindow,
   nsIWidget* parentWidget, PRInt32 x, PRInt32 y, PRInt32 cx, PRInt32 cy)   
{
   NS_ENSURE_ARG(parentWidget);  // DocShells must get a widget for a parent
   NS_ENSURE_STATE(!mCreated && InitInfo());

   mParentWidget = parentWidget;
   mInitInfo->x = x;
   mInitInfo->y = y;
   mInitInfo->cx = cx;
   mInitInfo->cy = cy;

   return NS_OK;
}

NS_IMETHODIMP nsDocShell::Create()
{
   NS_ENSURE_STATE(!mCreated);

   // Use mBaseInitInfo to do create
   // Then delete mBaseInitInfo
   //XXX First Check
  /*
  Tells the window that intialization and setup is complete.  When this is
  called the window can actually create itself based on the setup
  information handed to it.
  */
   return NS_ERROR_FAILURE;
}

NS_IMETHODIMP nsDocShell::Destroy()
{
   // We don't support the dynamic destroy and recreate on the object.  Just
   // create a new object!
   return NS_ERROR_NOT_IMPLEMENTED;
}

NS_IMETHODIMP nsDocShell::SetPosition(PRInt32 x, PRInt32 y)
{
   if(mContentViewer)
      NS_ENSURE_SUCCESS(mContentViewer->Move(x, y), NS_ERROR_FAILURE);
   else if(InitInfo())
      {
      mInitInfo->x = x;
      mInitInfo->y = y;
      }
   else
      NS_ENSURE_TRUE(PR_FALSE, NS_ERROR_FAILURE);

   return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetPosition(PRInt32* aX, PRInt32* aY)
{
   PRInt32 dummyHolder;
   return GetPositionAndSize(aX, aY, &dummyHolder, &dummyHolder);
}

NS_IMETHODIMP nsDocShell::SetSize(PRInt32 cx, PRInt32 cy, PRBool fRepaint)
{
   if(mContentViewer)
      {
      PRInt32 x;
      PRInt32 y;

      NS_ENSURE_SUCCESS(GetPosition(&x, &y), NS_ERROR_FAILURE);

      //XXX Border figured in here or is that handled elsewhere?
      nsRect bounds(x, y, cx, cy);

      NS_ENSURE_SUCCESS(mContentViewer->SetBounds(bounds), NS_ERROR_FAILURE);
      }
   else if(InitInfo())
      {
      mInitInfo->cx = cx;
      mInitInfo->cy = cy;
      }
   else
      NS_ENSURE_TRUE(PR_FALSE, NS_ERROR_FAILURE);

   return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetSize(PRInt32* aCX, PRInt32* aCY)
{
   PRInt32 dummyHolder;
   return GetPositionAndSize(&dummyHolder, &dummyHolder, aCX, aCY);
}

NS_IMETHODIMP nsDocShell::SetPositionAndSize(PRInt32 x, PRInt32 y, PRInt32 cx,
   PRInt32 cy, PRBool fRepaint)
{
   if(mContentViewer)
      {
      //XXX Border figured in here or is that handled elsewhere?
      nsRect bounds(x, y, cx, cy);

      NS_ENSURE_SUCCESS(mContentViewer->SetBounds(bounds), NS_ERROR_FAILURE);
      }
   else if(InitInfo())
      {
      mInitInfo->x = x;
      mInitInfo->y = y;
      mInitInfo->cx = cx;
      mInitInfo->cy = cy;
      }
   else
      NS_ENSURE_TRUE(PR_FALSE, NS_ERROR_FAILURE);

   return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetPositionAndSize(PRInt32* x, PRInt32* y, PRInt32* cx,
   PRInt32* cy)
{
   NS_ENSURE_ARG_POINTER(x && y && cx && cy);

   if(mContentViewer)
      {
      nsRect bounds;

      NS_ENSURE_SUCCESS(mContentViewer->GetBounds(bounds), NS_ERROR_FAILURE);

      *x = bounds.x;
      *y = bounds.y;
      *cx = bounds.width;
      *cy = bounds.height;
      }
   else if(InitInfo())
      {
      *x = mInitInfo->x;
      *y = mInitInfo->y;
      *cx = mInitInfo->cx;
      *cy = mInitInfo->cy;
      }
   else
      NS_ENSURE_TRUE(PR_FALSE, NS_ERROR_FAILURE);

   return NS_OK;
}

NS_IMETHODIMP nsDocShell::Repaint(PRBool aForce)
{
   
   //XXX First Check
  /** 
   * Tell the window to repaint itself
   * @param aForce - if true, repaint immediately
   *                 if false, the window may defer repainting as it sees fit.
   */

   /* XXX Implement Tell our view to repaint

     if (mWindow) {
    mWindow->Invalidate(aForce);
  }

  nsresult rv;
  nsCOMPtr<nsIViewManager> viewManager;
  rv = GetViewManager(getter_AddRefs(viewManager));
  if (NS_FAILED(rv)) { return rv; }
  if (!viewManager) { return NS_ERROR_NULL_POINTER; }

  //XXX: what about aForce?
  rv = viewManager->UpdateAllViews(0);
  return rv;

   */
   return NS_ERROR_FAILURE;
}

NS_IMETHODIMP nsDocShell::GetParentWidget(nsIWidget** parentWidget)
{
   NS_ENSURE_ARG_POINTER(parentWidget);

   *parentWidget = mParentWidget;
   NS_IF_ADDREF(*parentWidget);

   return NS_OK;
}

NS_IMETHODIMP nsDocShell::SetParentWidget(nsIWidget* parentWidget)
{
   NS_ENSURE_STATE(!mCreated);

   mParentWidget = parentWidget;

   return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetParentNativeWindow(nativeWindow* parentNativeWindow)
{
   NS_ENSURE_ARG_POINTER(parentNativeWindow);

   if(mParentWidget)
      *parentNativeWindow = mParentWidget->GetNativeData(NS_NATIVE_WIDGET);
   else
      *parentNativeWindow = nsnull;

   return NS_OK;
}

NS_IMETHODIMP nsDocShell::SetParentNativeWindow(nativeWindow parentNativeWindow)
{
   return NS_ERROR_NOT_IMPLEMENTED;
}

NS_IMETHODIMP nsDocShell::GetVisibility(PRBool* aVisibility)
{
  NS_ENSURE_ARG_POINTER(aVisibility);

  if(!mCreated) {
    *aVisibility = mInitInfo->visible;
  }
  else
  {
    // get the pres shell
    nsCOMPtr<nsIPresShell> presShell;
    NS_ENSURE_SUCCESS(GetPresShell(getter_AddRefs(presShell)), NS_ERROR_FAILURE);
    NS_ENSURE_TRUE(presShell, NS_ERROR_FAILURE);

    // get the view manager
    nsCOMPtr<nsIViewManager> vm;
    NS_ENSURE_SUCCESS(presShell->GetViewManager(getter_AddRefs(vm)), NS_ERROR_FAILURE);
    NS_ENSURE_TRUE(vm, NS_ERROR_FAILURE);

    // get the root view
    nsIView *rootView=nsnull; // views are not ref counted
    NS_ENSURE_SUCCESS(vm->GetRootView(rootView), NS_ERROR_FAILURE);
    NS_ENSURE_TRUE(rootView, NS_ERROR_FAILURE);

    // convert the view's visibility attribute to a bool
    nsViewVisibility vis;
    NS_ENSURE_TRUE(rootView->GetVisibility(vis), NS_ERROR_FAILURE); 
    if (nsViewVisibility_kHide==vis) {
      *aVisibility = PR_FALSE;
    }
    else {
      *aVisibility = PR_TRUE;
    }
  }

  return NS_OK;
}

NS_IMETHODIMP nsDocShell::SetVisibility(PRBool visibility)
{
   if(!mCreated)
      mInitInfo->visible = visibility;
   else
      {

     // NS_ENSURE_SUCCESS(mContentViewer->
      // XXX Set underlying control visibility
      }

   return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetMainWidget(nsIWidget** mainWidget)
{
   NS_ENSURE_ARG_POINTER(mainWidget);

   // For now we don't create our own widget, so simply return the parent one. 
   *mainWidget = mParentWidget;
   NS_IF_ADDREF(*mainWidget);

   return NS_OK;
}

NS_IMETHODIMP nsDocShell::SetFocus()
{
   //XXX First Check
  /**
  * Give the window focus.
  */

   /* XXX implement

     if (mWindow) {
    mWindow->SetFocus();
  }

  return NS_OK;

   */
   return NS_ERROR_FAILURE;
}

NS_IMETHODIMP nsDocShell::FocusAvailable(nsIBaseWindow* aCurrentFocus, 
   PRBool* aTookFocus)
{
   NS_ENSURE_ARG_POINTER(aTookFocus);

   // Next person we should call is first the parent otherwise the 
   // docshell tree owner.
   nsCOMPtr<nsIBaseWindow> nextCallWin(do_QueryInterface(mParent));
   if(!nextCallWin)
      {//XXX Enable this when docShellTreeOwner is added
      //nextCallWin = do_QueryInterface(mDocShellTreeOwner);
      }

   //If the current focus is us, offer it to the next owner.
   if(aCurrentFocus == NS_STATIC_CAST(nsIBaseWindow*, this))
      {
      if(nextCallWin)
         return nextCallWin->FocusAvailable(aCurrentFocus, aTookFocus);
      return NS_OK;
      }

   //Otherwise, check the chilren and offer it to the next sibling.
   PRInt32 i;
   PRInt32 n = mChildren.Count();
   for(i = 0; i < n; i++)
      {
      nsCOMPtr<nsIBaseWindow> 
         child(do_QueryInterface((nsISupports*)mChildren.ElementAt(i)));
      if(child.get() == aCurrentFocus)
         {
         while(++i < n)
            {
            child = do_QueryInterface((nsISupports*)mChildren.ElementAt(i));
            if(NS_SUCCEEDED(child->SetFocus()))
               {
               *aTookFocus = PR_TRUE;
               return NS_OK;
               }
            }
         }
      }
   if(nextCallWin)
      return nextCallWin->FocusAvailable(aCurrentFocus, aTookFocus);
   return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetTitle(PRUnichar** aTitle)
{
   NS_ENSURE_ARG_POINTER(aTitle);

   *aTitle = mTitle.ToNewUnicode();
   return NS_OK;
}

NS_IMETHODIMP nsDocShell::SetTitle(const PRUnichar* aTitle)
{
   // Store local title
   mTitle = aTitle;

   nsCOMPtr<nsIDocShellTreeItem> parent;
   GetSameTypeParent(getter_AddRefs(parent));

   // When title is set on the top object it should then be passed to the 
   // tree owner.
   if(!parent)
      {
      nsCOMPtr<nsIBaseWindow> treeOwnerAsWin(do_QueryInterface(mTreeOwner));
      if(!treeOwnerAsWin)
         return NS_OK;

      treeOwnerAsWin->SetTitle(aTitle);
      }

   return NS_OK;
}

//*****************************************************************************
// nsDocShell::nsIScrollable
//*****************************************************************************   

NS_IMETHODIMP nsDocShell::GetCurScrollPos(PRInt32 scrollOrientation, 
   PRInt32* curPos)
{
   NS_ENSURE_ARG_POINTER(curPos);

   nsCOMPtr<nsIScrollableView> scrollView;
   NS_ENSURE_SUCCESS(GetRootScrollableView(getter_AddRefs(scrollView)), 
      NS_ERROR_FAILURE);

   nscoord x, y;
   NS_ENSURE_SUCCESS(scrollView->GetScrollPosition(x, y), NS_ERROR_FAILURE);

   switch(scrollOrientation)
      {
      case ScrollOrientation_X:
         *curPos = x;
         return NS_OK;

      case ScrollOrientation_Y:
         *curPos = y;
         return NS_OK;

      default:
         NS_ENSURE_TRUE(PR_FALSE, NS_ERROR_INVALID_ARG);
      }
   return NS_ERROR_FAILURE;
}

NS_IMETHODIMP nsDocShell::SetCurScrollPos(PRInt32 scrollOrientation, 
   PRInt32 curPos)
{
   nsCOMPtr<nsIScrollableView> scrollView;
   NS_ENSURE_SUCCESS(GetRootScrollableView(getter_AddRefs(scrollView)), 
      NS_ERROR_FAILURE);

   PRInt32 other;
   PRInt32 x;
   PRInt32 y;

   GetCurScrollPos(scrollOrientation, &other);

   switch(scrollOrientation)
      {
      case ScrollOrientation_X:
         x = curPos;
         y = other;
         break;

      case ScrollOrientation_Y:
         x = other;
         y = curPos;
         break;

      default:
         NS_ENSURE_TRUE(PR_FALSE, NS_ERROR_INVALID_ARG);
      }

   NS_ENSURE_SUCCESS(scrollView->ScrollTo(x, y, NS_VMREFRESH_IMMEDIATE),
      NS_ERROR_FAILURE);
   return NS_OK;
}

NS_IMETHODIMP nsDocShell::SetCurScrollPosEx(PRInt32 curHorizontalPos, 
   PRInt32 curVerticalPos)
{
   nsCOMPtr<nsIScrollableView> scrollView;
   NS_ENSURE_SUCCESS(GetRootScrollableView(getter_AddRefs(scrollView)), 
      NS_ERROR_FAILURE);

   NS_ENSURE_SUCCESS(scrollView->ScrollTo(curHorizontalPos, curVerticalPos, 
      NS_VMREFRESH_IMMEDIATE), NS_ERROR_FAILURE);
   return NS_OK;
}

// XXX This is wrong
NS_IMETHODIMP nsDocShell::GetScrollRange(PRInt32 scrollOrientation,
   PRInt32* minPos, PRInt32* maxPos)
{
   NS_ENSURE_ARG_POINTER(minPos && maxPos);

   nsCOMPtr<nsIScrollableView> scrollView;
   NS_ENSURE_SUCCESS(GetRootScrollableView(getter_AddRefs(scrollView)), 
      NS_ERROR_FAILURE);

   PRInt32 cx;
   PRInt32 cy;
   
   NS_ENSURE_SUCCESS(scrollView->GetContainerSize(&cx, &cy), NS_ERROR_FAILURE);
   *minPos = 0;
   
   switch(scrollOrientation)
      {
      case ScrollOrientation_X:
         *maxPos = cx;
         return NS_OK;

      case ScrollOrientation_Y:
         *maxPos = cy;
         return NS_OK;

      default:
         NS_ENSURE_TRUE(PR_FALSE, NS_ERROR_INVALID_ARG);
      }

   return NS_ERROR_FAILURE;
}

NS_IMETHODIMP nsDocShell::SetScrollRange(PRInt32 scrollOrientation,
   PRInt32 minPos, PRInt32 maxPos)
{
   //XXX First Check
  /*
  Retrieves or Sets the valid ranges for the thumb.  When maxPos is set to 
  something less than the current thumb position, curPos is set = to maxPos.

  @return NS_OK - Setting or Getting completed successfully.
        NS_ERROR_INVALID_ARG - returned when curPos is not within the
          minPos and maxPos.
  */
   return NS_ERROR_FAILURE;
}

NS_IMETHODIMP nsDocShell::SetScrollRangeEx(PRInt32 minHorizontalPos,
   PRInt32 maxHorizontalPos, PRInt32 minVerticalPos, PRInt32 maxVerticalPos)
{
   //XXX First Check
  /*
  Retrieves or Sets the valid ranges for the thumb.  When maxPos is set to 
  something less than the current thumb position, curPos is set = to maxPos.

  @return NS_OK - Setting or Getting completed successfully.
        NS_ERROR_INVALID_ARG - returned when curPos is not within the
          minPos and maxPos.
  */
   return NS_ERROR_FAILURE;
}

NS_IMETHODIMP nsDocShell::GetScrollbarPreferences(PRInt32 scrollOrientation,
   PRInt32* scrollbarPref)
{
   NS_ENSURE_ARG_POINTER(scrollbarPref);

   nsCOMPtr<nsIScrollableView> scrollView;
   NS_ENSURE_SUCCESS(GetRootScrollableView(getter_AddRefs(scrollView)), 
      NS_ERROR_FAILURE);

   // XXX This is all evil, we need to convert.  We don't know our prefs
   // are the same as this interfaces.
 /*  nsScrollPreference scrollPref;

   NS_ENSURE_SUCCESS(scrollView->GetScrollPreference(scrollPref), 
      NS_ERROR_FAILURE);

   *scrollbarPref = scrollPref; */

   return NS_OK;
}

NS_IMETHODIMP nsDocShell::SetScrollbarPreferences(PRInt32 scrollOrientation,
   PRInt32 scrollbarPref)
{
   nsCOMPtr<nsIScrollableView> scrollView;
   NS_ENSURE_SUCCESS(GetRootScrollableView(getter_AddRefs(scrollView)), 
      NS_ERROR_FAILURE);

   // XXX This is evil.  We should do a mapping, we don't know our prefs
   // are the same as this interface.  In fact it doesn't compile
  /* nsScrollPreference scrollPref = scrollbarPref;
   NS_ENSURE_SUCCESS(scrollView->SetScrollPreference(scrollPref), 
      NS_ERROR_FAILURE);  */

   return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetScrollbarVisibility(PRBool* verticalVisible,
   PRBool* horizontalVisible)
{
   nsCOMPtr<nsIScrollableView> scrollView;
   NS_ENSURE_SUCCESS(GetRootScrollableView(getter_AddRefs(scrollView)), 
      NS_ERROR_FAILURE);

   PRBool vertVisible;
   PRBool horizVisible;

   NS_ENSURE_SUCCESS(scrollView->GetScrollbarVisibility(&vertVisible,
      &horizVisible), NS_ERROR_FAILURE);

   if(verticalVisible)
      *verticalVisible = vertVisible;
   if(horizontalVisible)
      *horizontalVisible = horizVisible;

   return NS_OK;
}

//*****************************************************************************
// nsDocShell::nsITextScroll
//*****************************************************************************   

NS_IMETHODIMP nsDocShell::ScrollByLines(PRInt32 numLines)
{
   nsCOMPtr<nsIScrollableView> scrollView;

   NS_ENSURE_SUCCESS(GetRootScrollableView(getter_AddRefs(scrollView)),
      NS_ERROR_FAILURE);

   NS_ENSURE_SUCCESS(scrollView->ScrollByLines(numLines), NS_ERROR_FAILURE);

   return NS_OK;
}

NS_IMETHODIMP nsDocShell::ScrollByPages(PRInt32 numPages)
{
   nsCOMPtr<nsIScrollableView> scrollView;

   NS_ENSURE_SUCCESS(GetRootScrollableView(getter_AddRefs(scrollView)),
      NS_ERROR_FAILURE);

   NS_ENSURE_SUCCESS(scrollView->ScrollByPages(numPages), NS_ERROR_FAILURE);

   return NS_OK;
}

///*****************************************************************************
// nsDocShell::nsIInterfaceRequestor
//*****************************************************************************   

NS_IMETHODIMP nsDocShell::GetInterface(const nsIID& aIID, void** aSink)
{
   NS_ENSURE_ARG_POINTER(aSink);

   if(aIID.Equals(NS_GET_IID(nsIURIContentListener)) &&
      NS_SUCCEEDED(EnsureContentListener()))
      *aSink = mContentListener;
   if(aIID.Equals(NS_GET_IID(nsIScriptGlobalObject)) &&
      NS_SUCCEEDED(EnsureScriptEnvironment()))
      *aSink = mScriptGlobal;
   else
      return QueryInterface(aIID, aSink);

   NS_IF_ADDREF(((nsISupports*)*aSink));
   return NS_OK;   
}

//*****************************************************************************
// nsDocShell::nsIScriptGlobalObjectOwner
//*****************************************************************************   

NS_IMETHODIMP nsDocShell::GetScriptGlobalObject(nsIScriptGlobalObject** aGlobal)
{
   NS_ENSURE_ARG_POINTER(aGlobal);
   NS_ENSURE_SUCCESS(EnsureScriptEnvironment(), NS_ERROR_FAILURE);

   *aGlobal = mScriptContext->GetGlobalObject(); // this returns an addrefed object..
   // NS_IF_ADDREF(*aGlobal);
   return NS_OK;
}

NS_IMETHODIMP nsDocShell::ReportScriptError(const char* aErrorString, 
   const char* aFileName, PRInt32 aLineNo, const char* aLineBuf)
{
   //XXX Needs some international work.
   nsAutoString error;
   error.SetString("JavaScript Error: ");
   error.Append(aErrorString);
   error += "\n";

   if(aFileName)
      {
      error += "URL: ";
      error += aFileName;
      error += "\n";
      }

   if(aLineNo)
      {
      error += "LineNo: ";
      error.Append(aLineNo, 10);
      error += "\n";
      }

   if(aLineBuf)
      {
      error += "Line text: '";
      error += aLineBuf;
      error += "'\n";
      }

   // XXX Should not do a printf
   char* errorStr = error.ToNewCString();
   if(errorStr)
      {
      printf("%s\n", errorStr);
      nsCRT::free(errorStr);
      }

   //XXXEMBEDDING Call embedding app with the error.

   // XXX Turn it off for now...there should be an Error method too
   //Alert(error.GetUnicode());

   return NS_OK;
}

//*****************************************************************************
// nsDocShell::nsIContentViewerContainer
//*****************************************************************************   

NS_IMETHODIMP nsDocShell::Embed(nsIContentViewer* aContentViewer, 
                                    const char      * aCommand,
                                    nsISupports     * aExtraInfo)
{
  NS_ENSURE_ARG_POINTER(aContentViewer);
  // null aCommand is ok
  // null aExtraInfo is ok

  WEB_TRACE(WEB_TRACE_CALLS,
      ("nsWebShell::Embed: this=%p aDocViewer=%p aCommand=%s aExtraInfo=%p",
       this, aContentViewer, aCommand ? aCommand : "", aExtraInfo));

  // (1) reset state, clean up any left-over data from previous embedding
  mContentViewer = nsnull;
  if (nsnull != mScriptContext) {
    mScriptContext->GC();
  }
  
  // (2) set the new content viewer
  mContentViewer = aContentViewer;

  // XXX: comment from webshell code --
  // check to see if we have a window to embed into --dwc0001
  /* Note we also need to check for the presence of a native widget. If the
     webshell is hidden before it's embedded, which can happen in an onload
     handler, the native widget is destroyed before this code is run.  This
     appears to be mostly harmless except on Windows, where the subsequent
     attempt to create a child window without a parent is met with disdain
     by the OS. It's handy, then, that GetNativeData on Windows returns
     null in this case. */
  /* XXX native window
  nsRect bounds;
  if(mWindow && mWindow->GetNativeData(NS_NATIVE_WIDGET)) 
  {
    mWindow->GetClientBounds(bounds);
    bounds.x = bounds.y = 0;
    rv = mContentViewer->Init(mWindow->GetNativeData(NS_NATIVE_WIDGET),
                              mDeviceContext,
                              mPrefs,
                              bounds,
                              mScrollPref);

    // If the history state has been set by session history,
    // set it on the pres shell now that we have a content
    // viewer.

    //XXX: history, should be removed
    if (mContentViewer && mHistoryState) {
      nsCOMPtr<nsIDocumentViewer> docv = do_QueryInterface(mContentViewer);
      if (nsnull != docv) {
        nsCOMPtr<nsIPresShell> shell;
        rv = docv->GetPresShell(*getter_AddRefs(shell));
        if (NS_SUCCEEDED(rv)) {
          rv = shell->SetHistoryState((nsILayoutHistoryState*) mHistoryState);
        }
      }
    }

    if (NS_SUCCEEDED(rv)) {
      mContentViewer->Show();
    }
  } else {
    mContentViewer = nsnull;
  }
  */

  // Now that we have switched documents, forget all of our children
  DestroyChildren();

  return NS_OK;
}

NS_IMETHODIMP nsDocShell::HandleUnknownContentType(nsIDocumentLoader* aLoader,
                                      nsIChannel* channel,
                                      const char *aContentType,
                                      const char *aCommand)
{
  NS_ENSURE_SUCCESS(PR_FALSE, NS_ERROR_NOT_IMPLEMENTED);
  return NS_OK;
}
  
//*****************************************************************************
// nsDocShell: Helper Routines
//*****************************************************************************   

nsDocShellInitInfo* nsDocShell::InitInfo()
{
   if(mInitInfo)
      return mInitInfo;
   return mInitInfo = new nsDocShellInitInfo();
}

nsresult nsDocShell::GetChildOffset(nsIDOMNode *aChild, nsIDOMNode* aParent,
   PRInt32* aOffset)
{
   NS_ENSURE_ARG_POINTER(aChild || aParent);
   
   nsCOMPtr<nsIDOMNodeList> childNodes;
   NS_ENSURE_SUCCESS(aParent->GetChildNodes(getter_AddRefs(childNodes)),
      NS_ERROR_FAILURE);
   NS_ENSURE_TRUE(childNodes, NS_ERROR_FAILURE);

   PRInt32 i=0;

   for( ; PR_TRUE; i++)
      {
      nsCOMPtr<nsIDOMNode> childNode;
      NS_ENSURE_SUCCESS(childNodes->Item(i, getter_AddRefs(childNode)), 
         NS_ERROR_FAILURE);
      NS_ENSURE_TRUE(childNode, NS_ERROR_FAILURE);

      if(childNode.get() == aChild)
         {
         *aOffset = i;
         return NS_OK;
         }
      }

   return NS_ERROR_FAILURE;
}

nsresult nsDocShell::GetRootScrollableView(nsIScrollableView** aOutScrollView)
{
   NS_ENSURE_ARG_POINTER(aOutScrollView);
   
   nsCOMPtr<nsIPresShell> shell;
   NS_ENSURE_SUCCESS(GetPresShell(getter_AddRefs(shell)), NS_ERROR_FAILURE);

   nsCOMPtr<nsIViewManager> viewManager;
   NS_ENSURE_SUCCESS(shell->GetViewManager(getter_AddRefs(viewManager)),
      NS_ERROR_FAILURE);

   NS_ENSURE_SUCCESS(viewManager->GetRootScrollableView(aOutScrollView),
      NS_ERROR_FAILURE);

   return NS_OK;
} 

nsresult nsDocShell::EnsureContentListener()
{
   if(mContentListener)
      return NS_OK;
   
   mContentListener = new nsDSURIContentListener();
   NS_ENSURE_TRUE(mContentListener, NS_ERROR_OUT_OF_MEMORY);

   mContentListener->AddRef();
   mContentListener->DocShell(this);

   return NS_OK;
}

nsresult nsDocShell::EnsureScriptEnvironment()
{
   if(mScriptContext)
      return NS_OK;

   nsCOMPtr<nsIScriptGlobalObject> scriptGlobalObject;

   NS_ENSURE_SUCCESS(NS_NewScriptGlobalObject(getter_AddRefs(scriptGlobalObject)), 
      NS_ERROR_FAILURE);

   //XXXWEBSHELL
   //mScriptGlobal->SetDocShell(NS_STATIC_CAST(nsIDocShell*, this));
   mScriptGlobal->SetGlobalObjectOwner(
      NS_STATIC_CAST(nsIScriptGlobalObjectOwner*, this));

   NS_ENSURE_SUCCESS(NS_CreateScriptContext(scriptGlobalObject, 
      getter_AddRefs(mScriptContext)), NS_ERROR_FAILURE);

   return NS_OK;
}

void nsDocShell::SetCurrentURI(nsIURI* aUri)
{
   mCurrentURI = aUri; //This assignment addrefs
}

nsresult nsDocShell::CreateContentViewer(const char* aContentType, 
   nsURILoadCommand aCommand, nsIChannel* aOpenedChannel, 
   nsIStreamListener** aContentHandler)
{
   NS_ENSURE_STATE(mCreated);

   //XXX We should return NS_ERROR_FAILURE if we can't create a new 
   // one and then leave our window in tact....
   //XXXQ Can we check the content type of the current content viewer
   // and reuse it without destroying it and re-creating it?

   // XXXIMPL Do cleanup....

   // Instantiate the content viewer object
   NS_ENSURE_SUCCESS(NewContentViewerObj(aContentType, aCommand, aOpenedChannel,
      aContentHandler), NS_ERROR_FAILURE);

   //XXXIMPL Do stuff found in embed here.  Don't call embed it is going away.

   return NS_ERROR_FAILURE;
}

nsresult nsDocShell::NewContentViewerObj(const char* aContentType,
   nsURILoadCommand aCommand, nsIChannel* aOpenedChannel, 
   nsIStreamListener** aContentHandler)
{
   //XXX This should probably be some category thing....
   char id[256];
   PR_snprintf(id, sizeof(id), NS_DOCUMENT_LOADER_FACTORY_PROGID_PREFIX "%s/%s",
      aCommand , aContentType);

   // Create an instance of the document-loader-factory
   nsCOMPtr<nsIDocumentLoaderFactory> docLoaderFactory(do_CreateInstance(id));
   NS_ENSURE_TRUE(docLoaderFactory, NS_ERROR_FAILURE);

   nsCOMPtr<nsILoadGroup> loadGroup(do_QueryInterface(mLoadCookie));
   // Now create an instance of the content viewer
   nsXPIDLCString strCommand;
   // go to the uri loader and ask it to convert the uri load command into a old
   // world style string
   nsresult rv = NS_OK;
   NS_WITH_SERVICE(nsIURILoader, pURILoader, NS_URI_LOADER_PROGID, &rv);
   if (NS_SUCCEEDED(rv))
    NS_ENSURE_SUCCESS(pURILoader->GetStringForCommand(aCommand, getter_Copies(strCommand)), NS_ERROR_FAILURE);
   
   NS_ENSURE_SUCCESS(docLoaderFactory->CreateInstance(strCommand, aOpenedChannel,
      loadGroup, aContentType, NS_STATIC_CAST(nsIContentViewerContainer*, this),
      nsnull /*XXXQ Need ExtraInfo???*/,
      aContentHandler, getter_AddRefs(mContentViewer)), NS_ERROR_FAILURE);

   return rv;
}

NS_IMETHODIMP
nsDocShell::FireStartDocumentLoad(nsIDocumentLoader* aLoader,
                                      nsIURI           * aURL,  //XXX: should be the channel?
                                      const char       * aCommand)
{
  NS_ENSURE_ARG_POINTER(aLoader);
  NS_ENSURE_ARG_POINTER(aURL);
  NS_ENSURE_ARG_POINTER(aCommand);

  nsCOMPtr<nsIDocumentViewer> docViewer;
  if (mScriptGlobal && (aLoader == mDocLoader.get())) 
  {
    docViewer = do_QueryInterface(mContentViewer);
    if (docViewer)
    {
      nsCOMPtr<nsIPresContext> presContext;
      NS_ENSURE_SUCCESS(docViewer->GetPresContext(*(getter_AddRefs(presContext))), NS_ERROR_FAILURE);
      if (presContext)
      {
        nsEventStatus status = nsEventStatus_eIgnore;
        nsMouseEvent event;
        event.eventStructType = NS_EVENT;
        event.message = NS_PAGE_UNLOAD;
        NS_ENSURE_SUCCESS(mScriptGlobal->HandleDOMEvent(presContext, 
                                                        &event, 
                                                        nsnull, 
                                                        NS_EVENT_FLAG_INIT, 
                                                        &status),
                          NS_ERROR_FAILURE);
      }
    }
  }

  if (aLoader == mDocLoader.get()) 
  {
    nsCOMPtr<nsIDocumentLoaderObserver> dlObserver;

    if (!mDocLoaderObserver && mParent) 
    {
      /* If this is a frame (in which case it would have a parent && doesn't
       * have a documentloaderObserver, get it from the rootWebShell
       */
      nsCOMPtr<nsIDocShellTreeItem> rootTreeItem;
      NS_ENSURE_SUCCESS(GetSameTypeRootTreeItem(getter_AddRefs(rootTreeItem)), 
         NS_ERROR_FAILURE);

      nsCOMPtr<nsIDocShell> rootAsDocShell(do_QueryInterface(rootTreeItem));
      if(rootAsDocShell)
         NS_ENSURE_SUCCESS(rootAsDocShell->GetDocLoaderObserver(getter_AddRefs(dlObserver)), 
            NS_ERROR_FAILURE);
    }
    else
    {
      dlObserver = do_QueryInterface(mDocLoaderObserver);  // we need this to addref
    }
    /*
     * Fire the OnStartDocumentLoad of the webshell observer
     */
    /* XXX This code means "notify dlObserver only if we're the top level webshell.
           I don't know why that would be, can't subdocument have doc loader observers?
     */
    if (/*(nsnull != mContainer) && */(nsnull != dlObserver))
    {
       NS_ENSURE_SUCCESS(dlObserver->OnStartDocumentLoad(mDocLoader, aURL, aCommand), 
                         NS_ERROR_FAILURE);
    }
  }

  return NS_OK;
}



NS_IMETHODIMP
nsDocShell::FireEndDocumentLoad(nsIDocumentLoader* aLoader,
                                    nsIChannel       * aChannel,
                                    nsresult           aStatus)
{
  NS_ENSURE_ARG_POINTER(aLoader);
  NS_ENSURE_ARG_POINTER(aChannel);

  nsCOMPtr<nsIURI> aURL;
  NS_ENSURE_SUCCESS(aChannel->GetURI(getter_AddRefs(aURL)), NS_ERROR_FAILURE);

  if (aLoader == mDocLoader.get())
  {
    if (mScriptGlobal && mContentViewer)
    {
      nsCOMPtr<nsIDocumentViewer> docViewer;
      docViewer = do_QueryInterface(mContentViewer);
      if (docViewer)
      {
        nsCOMPtr<nsIPresContext> presContext;
        NS_ENSURE_SUCCESS(docViewer->GetPresContext(*(getter_AddRefs(presContext))), NS_ERROR_FAILURE);
        if (presContext)
        {
          nsEventStatus status = nsEventStatus_eIgnore;
          nsMouseEvent event;
          event.eventStructType = NS_EVENT;
          event.message = NS_PAGE_LOAD;
          NS_ENSURE_SUCCESS(mScriptGlobal->HandleDOMEvent(presContext, 
                                                          &event, 
                                                          nsnull, 
                                                          NS_EVENT_FLAG_INIT, 
                                                          &status),
                            NS_ERROR_FAILURE);
        }
      }
    }

    // Fire the EndLoadURL of the web shell container
    /* XXX: what replaces mContainer?
    if (nsnull != aURL) 
    {
      nsAutoString urlString;
      char* spec;
      rv = aURL->GetSpec(&spec);
      if (NS_SUCCEEDED(rv)) 
      {
        urlString = spec;
        if (nsnull != mContainer) {
          rv = mContainer->EndLoadURL(this, urlString.GetUnicode(), 0);
        }
        nsCRT::free(spec);
      }
    }
    */

    nsCOMPtr<nsIDocumentLoaderObserver> dlObserver;
    if (!mDocLoaderObserver && mParent) 
    {
      // If this is a frame (in which case it would have a parent && doesn't
      // have a documentloaderObserver, get it from the rootWebShell
      nsCOMPtr<nsIDocShellTreeItem> rootTreeItem;
      NS_ENSURE_SUCCESS(GetSameTypeRootTreeItem(getter_AddRefs(rootTreeItem)), 
         NS_ERROR_FAILURE);

      nsCOMPtr<nsIDocShell> rootAsDocShell(do_QueryInterface(rootTreeItem));
      if(rootAsDocShell)
         NS_ENSURE_SUCCESS(rootAsDocShell->GetDocLoaderObserver(getter_AddRefs(dlObserver)),
            NS_ERROR_FAILURE);
    }
    else
    {
      /* Take care of the Trailing slash situation */
/* XXX: session history stuff, should be taken care of external to the docshell
      if (mSHist)
        CheckForTrailingSlash(aURL);
*/
      dlObserver = do_QueryInterface(mDocLoaderObserver);  // we need this to addref
    }

    /*
     * Fire the OnEndDocumentLoad of the DocLoaderobserver
     */
    if (dlObserver && aURL) {
       NS_ENSURE_SUCCESS(dlObserver->OnEndDocumentLoad(mDocLoader, aChannel, aStatus), 
                         NS_ERROR_FAILURE);
    }

    /* put the new document in the doc tree */
    NS_ENSURE_SUCCESS(InsertDocumentInDocTree(), NS_ERROR_FAILURE);
  }

  return NS_OK;
}

NS_IMETHODIMP nsDocShell::InsertDocumentInDocTree()
{
   nsCOMPtr<nsIDocShell> parent(do_QueryInterface(mParent));
  if(parent)
  {
    // Get the document object for the parent
    nsCOMPtr<nsIContentViewer> parentContentViewer;
    NS_ENSURE_SUCCESS(parent->GetContentViewer(getter_AddRefs(parentContentViewer)), 
                      NS_ERROR_FAILURE);
    NS_ENSURE_TRUE(parentContentViewer, NS_ERROR_FAILURE);
    nsCOMPtr<nsIDocumentViewer> parentDocViewer;
    parentDocViewer = do_QueryInterface(parentContentViewer);
    NS_ENSURE_TRUE(parentDocViewer, NS_ERROR_FAILURE);

    nsCOMPtr<nsIDocument> parentDoc;
    NS_ENSURE_SUCCESS(parentDocViewer->GetDocument(*getter_AddRefs(parentDoc)), NS_ERROR_FAILURE);
    NS_ENSURE_TRUE(parentDoc, NS_ERROR_FAILURE);

    // Get the document object for this
    nsCOMPtr<nsIDocumentViewer> docViewer;
    docViewer = do_QueryInterface(mContentViewer);
    NS_ENSURE_TRUE(docViewer, NS_ERROR_FAILURE);

    nsCOMPtr<nsIDocument> doc;
    NS_ENSURE_SUCCESS(docViewer->GetDocument(*getter_AddRefs(doc)), NS_ERROR_FAILURE);
    NS_ENSURE_TRUE(doc, NS_ERROR_FAILURE);

    doc->SetParentDocument(parentDoc);
    parentDoc->AddSubDocument(doc);
  }
  return NS_OK;
}

NS_IMETHODIMP nsDocShell::DestroyChildren()
{
   PRInt32 i, n = mChildren.Count();
   nsCOMPtr<nsIDocShellTreeItem>   shell;
   for (i = 0; i < n; i++) 
      {
      shell = dont_AddRef((nsIDocShellTreeItem*)mChildren.ElementAt(i));
      if(!NS_WARN_IF_FALSE(shell, "docshell has null child"))
         shell->SetParent(nsnull);
      }
   mChildren.Clear();
   return NS_OK;
}

nsresult nsDocShell::GetPrimaryFrameFor(nsIContent* content, nsIFrame** frame)
{
   //XXX Implement
   return NS_ERROR_FAILURE;
}