pjs/docshell/base/nsDocShell.cpp

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * 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>
 *   Peter Annema <disttsc@bart.nl>
 *   Dan Rosen <dr@netscape.com>
 */

#include "nsIComponentManager.h"
#include "nsIContent.h"
#include "nsIDocument.h"
#include "nsIDOMDocument.h"
#include "nsIDOMElement.h"
#include "nsIDocumentViewer.h"
#include "nsIDocumentLoaderFactory.h"
#include "nsIPluginHost.h"
#include "nsCURILoader.h"
#include "nsLayoutCID.h"
#include "nsNetUtil.h"
#include "nsRect.h"
#include "prprf.h"
#include "nsIMarkupDocumentViewer.h"
#include "nsXPIDLString.h"
#include "nsIChromeEventHandler.h"
#include "nsIDOMWindowInternal.h"
#include "nsIWebBrowserChrome.h"
#include "nsPoint.h"
#include "nsGfxCIID.h"
#include "nsIPrompt.h"
#include "nsIAuthPrompt.h"
#include "nsTextFormatter.h"
#include "nsIHTTPEventSink.h"
#include "nsISecurityEventSink.h"
#include "nsScriptSecurityManager.h"
#include "nsDocumentCharsetInfoCID.h"

// Local Includes
#include "nsDocShell.h"
#include "nsDocShellLoadInfo.h"
#include "nsCDefaultURIFixup.h"
#include "nsDocShellEnumerator.h"

// Helper Classes
#include "nsDOMError.h"
#include "nsEscape.h"
#include "nsHTTPEnums.h"

// Interfaces Needed
#include "nsIHTTPChannel.h"
#include "nsIDataChannel.h"
#include "nsIProgressEventSink.h"
#include "nsIWebProgress.h"
#include "nsILayoutHistoryState.h"
#include "nsITimer.h"
#include "nsIFileStream.h"
#include "nsISHistoryInternal.h"
#include "nsIPrincipal.h"

#include "nsPIDOMWindow.h"
#include "nsIDOMDocument.h"
#include "nsICachingChannel.h"

// For reporting errors with the console service.
// These can go away if error reporting is propagated up past nsDocShell.
#include "nsIConsoleService.h"
#include "nsIScriptError.h"

// used to dispatch urls to default protocol handlers
#include "nsCExternalHandlerService.h"
#include "nsIExternalProtocolService.h"

#include "nsIFocusController.h"

#include "nsITextToSubURI.h"

#include "prlog.h"

// this is going away - see
// http://bugzilla.mozilla.org/show_bug.cgi?id=71482
#include "nsIBrowserHistory.h"

#include "nsIEventStateManager.h"

#ifdef IBMBIDI
#include "nsIUBidiUtils.h"
#endif

#include "nsIFrame.h"
#include "nsIStyleContext.h"

// for embedding
#include "nsIEmbeddingSiteWindow.h"
#include "nsIWebBrowserChromeFocus.h"

static NS_DEFINE_IID(kDeviceContextCID, NS_DEVICE_CONTEXT_CID);
static NS_DEFINE_CID(kSimpleURICID, NS_SIMPLEURI_CID);
static NS_DEFINE_CID(kDocumentCharsetInfoCID, NS_DOCUMENTCHARSETINFO_CID);
static NS_DEFINE_CID(kPluginManagerCID, NS_PLUGINMANAGER_CID);
static NS_DEFINE_CID(kSecurityManagerCID, NS_SCRIPTSECURITYMANAGER_CID);

//
// Local function prototypes
//

/**

 * Used in AddHeadersToChannel

 */

static NS_METHOD AHTC_WriteFunc(nsIInputStream * in,
                                void *closure,
                                const char *fromRawSegment,
                                PRUint32 toOffset,
                                PRUint32 count, PRUint32 * writeCount);

#ifdef PR_LOGGING
static PRLogModuleInfo* gDocShellLog;
#endif

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

nsDocShell::nsDocShell():
    mContentListener(nsnull),
    mInitInfo(nsnull),
    mMarginWidth(0),
    mMarginHeight(0),
    mItemType(typeContent),
    mCurrentScrollbarPref(-1, -1),
    mDefaultScrollbarPref(-1, -1),
    mInitialPageLoad(PR_TRUE),
    mAllowPlugins(PR_TRUE),
    mAllowJavascript(PR_TRUE),
    mAllowMetaRedirects(PR_TRUE),
    mAllowSubframes(PR_TRUE),
    mAppType(nsIDocShell::APP_TYPE_UNKNOWN),
    mBusyFlags(BUSY_FLAGS_NONE),
    mEODForCurrentDocument(PR_FALSE),
    mURIResultedInDocument(PR_FALSE),
    mUseExternalProtocolHandler(PR_FALSE),
    mDisallowPopupWindows(PR_FALSE),
    mParent(nsnull),
    mTreeOwner(nsnull),
    mChromeEventHandler(nsnull)
{
    NS_INIT_REFCNT();
#ifdef PR_LOGGING
    if (! gDocShellLog)
        gDocShellLog = PR_NewLogModule("nsDocShell");
#endif
}

nsDocShell::~nsDocShell()
{
    Destroy();
}

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);
        nsCOMPtr<nsIBaseWindow> shellWin(do_QueryInterface(shell));
        if (shellWin)
            shellWin->Destroy();
    }
    mChildren.Clear();
    return NS_OK;
}

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

NS_IMPL_THREADSAFE_ADDREF(nsDocShell)
NS_IMPL_THREADSAFE_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(nsIDocShellHistory)
    NS_INTERFACE_MAP_ENTRY(nsIWebNavigation)
    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_ENTRY(nsIRefreshURI)
    NS_INTERFACE_MAP_ENTRY(nsIWebProgressListener)
    NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
NS_INTERFACE_MAP_END_THREADSAFE

///*****************************************************************************
// 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;
    }
    else if (aIID.Equals(NS_GET_IID(nsIScriptGlobalObject)) &&
             NS_SUCCEEDED(EnsureScriptEnvironment())) {
        *aSink = mScriptGlobal;
    }
    else if (aIID.Equals(NS_GET_IID(nsIDOMWindowInternal)) &&
             NS_SUCCEEDED(EnsureScriptEnvironment())) {
        NS_ENSURE_SUCCESS(mScriptGlobal->
                          QueryInterface(NS_GET_IID(nsIDOMWindowInternal),
                                         aSink), NS_ERROR_FAILURE);
        return NS_OK;
    }
    else if (aIID.Equals(NS_GET_IID(nsIDOMWindow)) &&
             NS_SUCCEEDED(EnsureScriptEnvironment())) {
        NS_ENSURE_SUCCESS(mScriptGlobal->
                          QueryInterface(NS_GET_IID(nsIDOMWindow), aSink),
                          NS_ERROR_FAILURE);
        return NS_OK;
    }
    else if (aIID.Equals(NS_GET_IID(nsIDOMDocument)) &&
             NS_SUCCEEDED(EnsureContentViewer())) {
        mContentViewer->GetDOMDocument((nsIDOMDocument **) aSink);
    }
    else if (aIID.Equals(NS_GET_IID(nsIPrompt))) {
        nsCOMPtr<nsIPrompt> prompter(do_GetInterface(mTreeOwner));
        if (prompter) {
            *aSink = prompter;
            NS_ADDREF((nsISupports *) * aSink);
            return NS_OK;
        }
        else
            return NS_NOINTERFACE;
    }
    else if (aIID.Equals(NS_GET_IID(nsIAuthPrompt))) {
        nsCOMPtr<nsIAuthPrompt> authPrompter(do_GetInterface(mTreeOwner));
        if (authPrompter) {
            *aSink = authPrompter;
            NS_ADDREF((nsISupports *) * aSink);
            return NS_OK;
        }
        else
            return NS_NOINTERFACE;
    }
    else if (aIID.Equals(NS_GET_IID(nsIProgressEventSink))
             || aIID.Equals(NS_GET_IID(nsIHTTPEventSink))
             || aIID.Equals(NS_GET_IID(nsIWebProgress))
             || aIID.Equals(NS_GET_IID(nsISecurityEventSink))) {
        nsCOMPtr<nsIURILoader>
            uriLoader(do_GetService(NS_URI_LOADER_CONTRACTID));
        NS_ENSURE_TRUE(uriLoader, NS_ERROR_FAILURE);
        nsCOMPtr<nsIDocumentLoader> docLoader;
        NS_ENSURE_SUCCESS(uriLoader->
                          GetDocumentLoaderForContext(NS_STATIC_CAST
                                                      (nsIDocShell *, this),
                                                      getter_AddRefs
                                                      (docLoader)),
                          NS_ERROR_FAILURE);
        if (docLoader) {
            nsCOMPtr<nsIInterfaceRequestor>
                requestor(do_QueryInterface(docLoader));
            return requestor->GetInterface(aIID, aSink);
        }
        else
            return NS_ERROR_FAILURE;
    }
    else if (aIID.Equals(NS_GET_IID(nsISHistory))) {
        nsCOMPtr<nsISHistory> shistory;
        nsresult
            rv =
            GetSessionHistory(getter_AddRefs(shistory));
        if (NS_SUCCEEDED(rv) && shistory) {
            *aSink = shistory;
            NS_ADDREF((nsISupports *) * aSink);
            return NS_OK;
        }
        return NS_NOINTERFACE;
    }
    else if (aIID.Equals(NS_GET_IID(nsIWebBrowserFind))) {
        nsresult rv = EnsureFind();
        if (NS_FAILED(rv)) return rv;

        *aSink = mFind;
        NS_ADDREF((nsISupports*)*aSink);
        return NS_OK;
    }
    else {
        return QueryInterface(aIID, aSink);
    }

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

PRUint32
nsDocShell::
ConvertDocShellLoadInfoToLoadType(nsDocShellInfoLoadType aDocShellLoadType)
{
    PRUint32 loadType = LOAD_NORMAL;

    switch (aDocShellLoadType) {
    case nsIDocShellLoadInfo::loadNormal:
        loadType = LOAD_NORMAL;
        break;
    case nsIDocShellLoadInfo::loadNormalReplace:
        loadType = LOAD_NORMAL_REPLACE;
        break;
    case nsIDocShellLoadInfo::loadHistory:
        loadType = LOAD_HISTORY;
        break;
    case nsIDocShellLoadInfo::loadReloadNormal:
        loadType = LOAD_RELOAD_NORMAL;
        break;
    case nsIDocShellLoadInfo::loadReloadBypassCache:
        loadType = LOAD_RELOAD_BYPASS_CACHE;
        break;
    case nsIDocShellLoadInfo::loadReloadBypassProxy:
        loadType = LOAD_RELOAD_BYPASS_PROXY;
        break;
    case nsIDocShellLoadInfo::loadReloadBypassProxyAndCache:
        loadType = LOAD_RELOAD_BYPASS_PROXY_AND_CACHE;
        break;
    case nsIDocShellLoadInfo::loadLink:
        loadType = LOAD_LINK;
        break;
    case nsIDocShellLoadInfo::loadRefresh:
        loadType = LOAD_REFRESH;
        break;
    }

    return loadType;
}

nsDocShellInfoLoadType
nsDocShell::ConvertLoadTypeToDocShellLoadInfo(PRUint32 aLoadType)
{
    nsDocShellInfoLoadType docShellLoadType = nsIDocShellLoadInfo::loadNormal;
    switch (aLoadType) {
    case LOAD_NORMAL:
        docShellLoadType = nsIDocShellLoadInfo::loadNormal;
        break;
    case LOAD_NORMAL_REPLACE:
        docShellLoadType = nsIDocShellLoadInfo::loadNormalReplace;
        break;
    case LOAD_HISTORY:
        docShellLoadType = nsIDocShellLoadInfo::loadHistory;
        break;
    case LOAD_RELOAD_NORMAL:
        docShellLoadType = nsIDocShellLoadInfo::loadReloadNormal;
        break;
    case LOAD_RELOAD_BYPASS_CACHE:
        docShellLoadType = nsIDocShellLoadInfo::loadReloadBypassCache;
        break;
    case LOAD_RELOAD_BYPASS_PROXY:
        docShellLoadType = nsIDocShellLoadInfo::loadReloadBypassProxy;
        break;
    case LOAD_RELOAD_BYPASS_PROXY_AND_CACHE:
        docShellLoadType = nsIDocShellLoadInfo::loadReloadBypassProxyAndCache;
        break;
    case LOAD_LINK:
        docShellLoadType = nsIDocShellLoadInfo::loadLink;
        break;
    case LOAD_REFRESH:
        docShellLoadType = nsIDocShellLoadInfo::loadRefresh;
        break;
    }

    return docShellLoadType;
}

//*****************************************************************************
// nsDocShell::nsIDocShell
//*****************************************************************************   
NS_IMETHODIMP
nsDocShell::LoadURI(nsIURI * aURI, nsIDocShellLoadInfo * aLoadInfo,
                        PRUint32 aLoadFlags)
{
    nsresult rv;
    nsCOMPtr<nsIURI> referrer;
    nsCOMPtr<nsISupports> owner;
    PRBool inheritOwner = PR_FALSE;
    PRBool stopActiveDoc = PR_FALSE;
    nsCOMPtr<nsISHEntry> shEntry;
    nsXPIDLCString target;
    PRUint32 loadType = MAKE_LOAD_TYPE(LOAD_NORMAL, aLoadFlags);

    NS_ENSURE_ARG(aURI);

    // Extract the info from the DocShellLoadInfo struct...
    if (aLoadInfo) {
        aLoadInfo->GetReferrer(getter_AddRefs(referrer));

        nsDocShellInfoLoadType lt = nsIDocShellLoadInfo::loadNormal;
        aLoadInfo->GetLoadType(&lt);
        switch (lt) {
        case nsIDocShellLoadInfo::loadNormal:
            loadType = LOAD_NORMAL;
            break;
        case nsIDocShellLoadInfo::loadNormalReplace:
            loadType = LOAD_NORMAL_REPLACE;
            break;
        case nsIDocShellLoadInfo::loadHistory:
            loadType = LOAD_HISTORY;
            break;
        case nsIDocShellLoadInfo::loadReloadNormal:
            loadType = LOAD_RELOAD_NORMAL;
            break;
        case nsIDocShellLoadInfo::loadReloadBypassCache:
            loadType = LOAD_RELOAD_BYPASS_CACHE;
            break;
        case nsIDocShellLoadInfo::loadReloadBypassProxy:
            loadType = LOAD_RELOAD_BYPASS_PROXY;
            break;
        case nsIDocShellLoadInfo::loadReloadBypassProxyAndCache:
            loadType = LOAD_RELOAD_BYPASS_PROXY_AND_CACHE;
            break;
        case nsIDocShellLoadInfo::loadLink:
            loadType = LOAD_LINK;
            break;
        case nsIDocShellLoadInfo::loadRefresh:
            loadType = LOAD_REFRESH;
            break;
        }

        aLoadInfo->GetOwner(getter_AddRefs(owner));
        aLoadInfo->GetInheritOwner(&inheritOwner);
        aLoadInfo->GetStopActiveDocument(&stopActiveDoc);
        aLoadInfo->GetSHEntry(getter_AddRefs(shEntry));
        aLoadInfo->GetTarget(getter_Copies(target));
    }

#ifdef PR_LOGGING
    if (PR_LOG_TEST(gDocShellLog, PR_LOG_DEBUG)) {
        nsXPIDLCString uristr;
        aURI->GetSpec(getter_Copies(uristr));
        PR_LOG(gDocShellLog, PR_LOG_DEBUG,
               ("nsDocShell[%p]: loading %s with flags 0x%08x",
                this, uristr.get(), aLoadFlags));
    }
#endif

    if (!shEntry && loadType != LOAD_NORMAL_REPLACE && mCurrentURI == nsnull) {
        /* Check if we are in the middle of loading a subframe whose parent
         * was originally loaded thro' Session History. ie., you were in a frameset
         * page, went somewhere else and clicked 'back'. The loading of the root page
         * is done and we are currently loading one of its children or sub-children.
         */
        nsCOMPtr<nsIDocShellTreeItem> parentAsItem;
        GetSameTypeParent(getter_AddRefs(parentAsItem));

        // Try to get your SHEntry from your parent
        if (parentAsItem) {
            nsCOMPtr<nsIDocShellHistory>
                parent(do_QueryInterface(parentAsItem));

            // XXX: Should we care if this QI fails?
            if (parent) {
                parent->GetChildSHEntry(mChildOffset, getter_AddRefs(shEntry));
                if (shEntry) {
                    //Get the proper loadType from the SHEntry.
                    PRUint32 lt;
                    shEntry->GetLoadType(&lt);
                    // Convert the DocShellInfoLoadType returned by the 
                    // previous function to loadType
                    loadType =
                        ConvertDocShellLoadInfoToLoadType((nsDocShellInfoLoadType) lt);
                }
            }
        }
    }
    if (shEntry) {
        // Load is from SH. SH does normal load only
        PR_LOG(gDocShellLog, PR_LOG_DEBUG,
               ("nsDocShell[%p]: loading from session history", this));

        rv = LoadHistoryEntry(shEntry, loadType);
    }
    else {
        rv = InternalLoad(aURI, referrer, owner, inheritOwner, stopActiveDoc,
                          (const char *) target, nsnull, nsnull, loadType,
                          nsnull);
    }

    return rv;
}

NS_IMETHODIMP
nsDocShell::LoadStream(nsIInputStream * aStream, nsIURI * aURI,
                       const char *aContentType, PRInt32 aContentLen,
                       nsIDocShellLoadInfo * aLoadInfo)
{
    NS_ENSURE_ARG(aStream);
    NS_ENSURE_ARG(aContentType);
    NS_ENSURE_ARG(aContentLen);

    // if the caller doesn't pass in a URI we need to create a dummy URI. necko
    // currently requires a URI in various places during the load. Some consumers
    // do as well.
    nsCOMPtr<nsIURI> uri = aURI;
    if (!uri) {
        // HACK ALERT
        nsresult rv = NS_OK;
        uri = do_CreateInstance(kSimpleURICID, &rv);
        if (NS_FAILED(rv))
            return rv;
        // Make sure that the URI spec "looks" like a protocol and path...
        // For now, just use a bogus protocol called "internal"
        rv = uri->SetSpec("internal:load-stream");
        if (NS_FAILED(rv))
            return rv;
    }

    LoadType loadType = LOAD_NORMAL;
    if (aLoadInfo) {
        nsDocShellInfoLoadType lt = nsIDocShellLoadInfo::loadNormal;
        (void) aLoadInfo->GetLoadType(&lt);
        switch (lt) {
        case nsIDocShellLoadInfo::loadNormal:
            loadType = LOAD_NORMAL;
            break;
        case nsIDocShellLoadInfo::loadNormalReplace:
            loadType = LOAD_NORMAL_REPLACE;
            break;
        case nsIDocShellLoadInfo::loadHistory:
            loadType = LOAD_HISTORY;
            break;
        case nsIDocShellLoadInfo::loadReloadNormal:
            loadType = LOAD_RELOAD_NORMAL;
            break;
        case nsIDocShellLoadInfo::loadReloadBypassCache:
            loadType = LOAD_RELOAD_BYPASS_CACHE;
            break;
        case nsIDocShellLoadInfo::loadReloadBypassProxy:
            loadType = LOAD_RELOAD_BYPASS_PROXY;
            break;
        case nsIDocShellLoadInfo::loadReloadBypassProxyAndCache:
            loadType = LOAD_RELOAD_BYPASS_PROXY_AND_CACHE;
            break;
        case nsIDocShellLoadInfo::loadLink:
            loadType = LOAD_LINK;
            break;
        case nsIDocShellLoadInfo::loadRefresh:
            loadType = LOAD_REFRESH;
            break;
        }
    }

    NS_ENSURE_SUCCESS(StopLoad(), NS_ERROR_FAILURE);
    // Cancel any timers that were set for this loader.
    (void) CancelRefreshURITimers();

    mLoadType = loadType;

    // build up a channel for this stream.
    nsCOMPtr<nsIChannel> channel;
    NS_ENSURE_SUCCESS(NS_NewInputStreamChannel
                      (getter_AddRefs(channel), uri, aStream, aContentType,
                       aContentLen), NS_ERROR_FAILURE);

    nsCOMPtr<nsIURILoader>
        uriLoader(do_GetService(NS_URI_LOADER_CONTRACTID));
    NS_ENSURE_TRUE(uriLoader, NS_ERROR_FAILURE);

    NS_ENSURE_SUCCESS(DoChannelLoad
                      (channel, nsIURILoader::viewNormal, nsnull, uriLoader),
                      NS_ERROR_FAILURE);
    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::CreateLoadInfo(nsIDocShellLoadInfo ** aLoadInfo)
{
    nsDocShellLoadInfo *loadInfo = new nsDocShellLoadInfo();
    NS_ENSURE_TRUE(loadInfo, NS_ERROR_OUT_OF_MEMORY);
    nsCOMPtr<nsIDocShellLoadInfo> localRef(loadInfo);

    *aLoadInfo = localRef;
    NS_ADDREF(*aLoadInfo);
    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::StopLoad()
{
    // Cancel any timers that were set for this loader.
    CancelRefreshURITimers();

    if (mLoadCookie) {
        nsCOMPtr<nsIURILoader> uriLoader =
            do_GetService(NS_URI_LOADER_CONTRACTID);
        if (uriLoader)
            uriLoader->Stop(mLoadCookie);
    }

    PRInt32 n;
    PRInt32 count = mChildren.Count();
    for (n = 0; n < count; n++) {
        nsIDocShellTreeItem *shellItem =
            (nsIDocShellTreeItem *) mChildren.ElementAt(n);
        nsCOMPtr<nsIDocShell> shell(do_QueryInterface(shellItem));
        if (shell)
            shell->StopLoad();
    }

    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::GetPresContext(nsIPresContext ** aPresContext)
{
    nsresult rv = NS_OK;

    NS_ENSURE_ARG_POINTER(aPresContext);
    *aPresContext = nsnull;

    if (mContentViewer) {
        nsCOMPtr<nsIDocumentViewer> docv(do_QueryInterface(mContentViewer));

        if (docv) {
            rv = docv->GetPresContext(*aPresContext);
        }
    }

    // Fail silently, if no PresContext is available...
    return rv;
}

NS_IMETHODIMP
nsDocShell::GetPresShell(nsIPresShell ** aPresShell)
{
    nsresult rv = NS_OK;

    NS_ENSURE_ARG_POINTER(aPresShell);
    *aPresShell = nsnull;

    nsCOMPtr<nsIPresContext> presContext;
    (void) GetPresContext(getter_AddRefs(presContext));

    if (presContext) {
        rv = presContext->GetShell(aPresShell);
    }

    return rv;
}

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);

    return mContentListener->GetParentContentListener(aParent);
}

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

    return mContentListener->SetParentContentListener(aParent);
}

NS_IMETHODIMP
nsDocShell::GetDocumentCharsetInfo(nsIDocumentCharsetInfo **
                                   aDocumentCharsetInfo)
{
    NS_ENSURE_ARG_POINTER(aDocumentCharsetInfo);

    // if the mDocumentCharsetInfo does not exist already, we create it now
    if (!mDocumentCharsetInfo) {
        nsresult res =
            nsComponentManager::CreateInstance(kDocumentCharsetInfoCID,
                                               NULL,
                                               NS_GET_IID
                                               (nsIDocumentCharsetInfo),
                                               getter_AddRefs
                                               (mDocumentCharsetInfo));
        if (NS_FAILED(res))
            return NS_ERROR_FAILURE;
    }

    *aDocumentCharsetInfo = mDocumentCharsetInfo;
    NS_IF_ADDREF(*aDocumentCharsetInfo);
    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::SetDocumentCharsetInfo(nsIDocumentCharsetInfo *
                                   aDocumentCharsetInfo)
{
    mDocumentCharsetInfo = aDocumentCharsetInfo;
    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::GetAllowPlugins(PRBool * aAllowPlugins)
{
    NS_ENSURE_ARG_POINTER(aAllowPlugins);

    *aAllowPlugins = mAllowPlugins;
    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::SetAllowPlugins(PRBool aAllowPlugins)
{
    mAllowPlugins = aAllowPlugins;
    //XXX should enable or disable a plugin host
    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::GetAllowJavascript(PRBool * aAllowJavascript)
{
    NS_ENSURE_ARG_POINTER(aAllowJavascript);

    *aAllowJavascript = mAllowJavascript;
    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::SetAllowJavascript(PRBool aAllowJavascript)
{
    mAllowJavascript = aAllowJavascript;
    return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetAllowMetaRedirects(PRBool * aReturn)
{
    NS_ENSURE_ARG_POINTER(aReturn);

    *aReturn = mAllowMetaRedirects;
    return NS_OK;
}

NS_IMETHODIMP nsDocShell::SetAllowMetaRedirects(PRBool aValue)
{
    mAllowMetaRedirects = aValue;
    return NS_OK;
}

NS_IMETHODIMP nsDocShell::GetAllowSubframes(PRBool * aAllowSubframes)
{
    NS_ENSURE_ARG_POINTER(aAllowSubframes);

    *aAllowSubframes = mAllowSubframes;
    return NS_OK;
}

NS_IMETHODIMP nsDocShell::SetAllowSubframes(PRBool aAllowSubframes)
{
    mAllowSubframes = aAllowSubframes;
    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::GetDocShellEnumerator(PRInt32 aItemType, PRInt32 aDirection, nsISimpleEnumerator **outEnum)
{
    NS_ENSURE_ARG_POINTER(outEnum);
    *outEnum = nsnull;
    
    nsDocShellEnumerator*   docShellEnum;
    if (aDirection == ENUMERATE_FORWARDS)
        docShellEnum = new nsDocShellForwardsEnumerator;
    else
        docShellEnum = new nsDocShellBackwardsEnumerator;
    
    if (!docShellEnum) return NS_ERROR_OUT_OF_MEMORY;
    
    nsresult rv = docShellEnum->SetEnumDocShellType(aItemType);
    if (NS_FAILED(rv)) return rv;

    rv = docShellEnum->SetEnumerationRootItem((nsIDocShellTreeItem *)this);
    if (NS_FAILED(rv)) return rv;

    rv = docShellEnum->First();
    if (NS_FAILED(rv)) return rv;
    
    docShellEnum->AddRef();     // ensure we don't lose the last ref inside the QueryInterface
    rv = docShellEnum->QueryInterface(NS_GET_IID(nsISimpleEnumerator), (void **)outEnum);
    docShellEnum->Release();
    return rv;
}

NS_IMETHODIMP
nsDocShell::GetAppType(PRUint32 * aAppType)
{
    *aAppType = mAppType;
    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::SetAppType(PRUint32 aAppType)
{
    mAppType = aAppType;
    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::GetZoom(float *zoom)
{
    NS_ENSURE_ARG_POINTER(zoom);
    NS_ENSURE_SUCCESS(EnsureDeviceContext(), NS_ERROR_FAILURE);

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

    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::SetZoom(float zoom)
{
    NS_ENSURE_SUCCESS(EnsureDeviceContext(), NS_ERROR_FAILURE);
    mDeviceContext->SetZoom(zoom);

    // 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 scrollable view
    nsIScrollableView *scrollableView = nsnull;
    vm->GetRootScrollableView(&scrollableView);
    if (scrollableView)
        scrollableView->ComputeScrollOffsets();

    // get the root view
    nsIView *rootView = nsnull; // views are not ref counted
    vm->GetRootView(rootView);
    if (rootView)
        vm->UpdateView(rootView, 0);

    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;
}

NS_IMETHODIMP
nsDocShell::GetBusyFlags(PRUint32 * aBusyFlags)
{
    NS_ENSURE_ARG_POINTER(aBusyFlags);

    *aBusyFlags = mBusyFlags;
    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));
    NS_ENSURE_STATE(!mParent);

    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;

    nsCOMPtr<nsIURIContentListener>
        parentURIListener(do_GetInterface(aParent));
    if (parentURIListener)
        SetParentURIContentListener(parentURIListener);
    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.EqualsWithConversion(aName)) {
        *_retval = NS_STATIC_CAST(nsIDocShellTreeItem *, this);
        NS_ADDREF(*_retval);
        return NS_OK;
    }

    // Second we check our children making sure not to ask a child if it
    // is the aRequestor.
    NS_ENSURE_SUCCESS(FindChildWithName(aName, PR_TRUE, 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)
{
    // Don't automatically set the progress based on the tree owner for frames
    if (!IsFrame()) {
        nsCOMPtr<nsIWebProgress> webProgress(do_QueryInterface(mLoadCookie));

        if (webProgress) {
            nsCOMPtr<nsIWebProgressListener>
                oldListener(do_QueryInterface(mTreeOwner));
            nsCOMPtr<nsIWebProgressListener>
                newListener(do_QueryInterface(aTreeOwner));

            if (oldListener) {
                webProgress->RemoveProgressListener(oldListener);
            }

            if (newListener) {
                webProgress->AddProgressListener(newListener);
            }
        }
    }

    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;
}

NS_IMETHODIMP
nsDocShell::SetChildOffset(PRInt32 aChildOffset)
{
    mChildOffset = aChildOffset;
    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::GetChildOffset(PRInt32 * aChildOffset)
{
    NS_ENSURE_ARG_POINTER(aChildOffset);
    *aChildOffset = mChildOffset;
    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);

    // Set the child's index in the parent's children list 
    // XXX What if the parent had different types of children?
    // XXX in that case docshell hierarchyand SH hierarchy won't match.
    PRInt32 childCount = mChildren.Count();
    aChild->SetChildOffset(childCount - 1);

    /* Set the child's global history if the parent has one */
    if (mGlobalHistory) {
        nsCOMPtr<nsIDocShellHistory>
            dsHistoryChild(do_QueryInterface(aChild));
        if (dsHistoryChild)
            dsHistoryChild->SetGlobalHistory(mGlobalHistory);
    }


    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);
        }
    }

    // Now take this document's charset and set the parentCharset field of the 
    // child's DocumentCharsetInfo to it. We'll later use that field, in the 
    // loading process, for the charset choosing algorithm.
    // If we fail, at any point, we just return NS_OK.
    // This code has some performance impact. But this will be reduced when 
    // the current charset will finally be stored as an Atom, avoiding the
    // alias resolution extra look-up.

    // we are NOT going to propagate the charset is this Chrome's docshell
    if (mItemType == nsIDocShellTreeItem::typeChrome)
        return NS_OK;

    nsresult res = NS_OK;

    // get the child's docCSInfo object
    nsCOMPtr<nsIDocumentCharsetInfo> dcInfo = NULL;
    res = childAsDocShell->GetDocumentCharsetInfo(getter_AddRefs(dcInfo));
    if (NS_FAILED(res) || (!dcInfo))
        return NS_OK;

    // get the parent's current charset
    nsCOMPtr<nsIDocumentViewer> docv(do_QueryInterface(mContentViewer));
    if (!docv)
        return NS_OK;
    nsCOMPtr<nsIDocument> doc;
    res = docv->GetDocument(*getter_AddRefs(doc));
    if (NS_FAILED(res) || (!doc))
        return NS_OK;
    nsAutoString parentCS;
    res = doc->GetDocumentCharacterSet(parentCS);
    if (NS_FAILED(res))
        return NS_OK;

    // set the child's parentCharset
    nsCOMPtr<nsIAtom> parentCSAtom(dont_AddRef(NS_NewAtom(parentCS)));
    res = dcInfo->SetParentCharset(parentCSAtom);
    if (NS_FAILED(res))
        return NS_OK;

    // printf("### 1 >>> Adding child. Parent CS = %s. ItemType = %d.\n", parentCS.ToNewCString(), mItemType);

    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, PRBool aSameType,
                              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);
        PRInt32 childType;
        child->GetItemType(&childType);

        if (aSameType && (childType != mItemType))
            continue;

        child->GetName(getter_Copies(childName));
        if (name.EqualsWithConversion(childName)) {
            *_retval = child;
            NS_ADDREF(*_retval);
            break;
        }

        if (childType != mItemType)     //Only ask it to check children if it is same type
            continue;

        if (aRecurse && (aRequestor != child))  // Only ask the child if it isn't the requestor
        {
            // 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,
                                                                 aSameType,
                                                                 NS_STATIC_CAST
                                                                 (nsIDocShellTreeItem
                                                                  *, this),
                                                                 _retval),
                                  NS_ERROR_FAILURE);
            }
        }
        if (*_retval)           // found it
            return NS_OK;
    }
    return NS_OK;
}

//*****************************************************************************
// nsDocShell::nsIDocShellHistory
//*****************************************************************************   
NS_IMETHODIMP
nsDocShell::GetChildSHEntry(PRInt32 aChildOffset, nsISHEntry ** aResult)
{
    nsresult rv = NS_OK;

    NS_ENSURE_ARG_POINTER(aResult);
    *aResult = nsnull;

    //
    // A nsISHEntry for a child is *only* available when the parent is in
    // the progress of loading a document too...
    //
    if (LSHE) {
        /* Get the parent's Load Type so that it can be set on the child too.
         * By default give a loadHistory value
         */
        PRUint32 loadType = nsIDocShellLoadInfo::loadHistory;
        LSHE->GetLoadType(&loadType);
        nsCOMPtr<nsISHContainer> container(do_QueryInterface(LSHE));
        if (container) {
            rv = container->GetChildAt(aChildOffset, aResult);
            if (*aResult) {
                (*aResult)->SetLoadType(loadType);
            }
        }
    }
    return rv;
}

NS_IMETHODIMP
nsDocShell::AddChildSHEntry(nsISHEntry * aCloneRef, nsISHEntry * aNewEntry,
                            PRInt32 aChildOffset)
{
    nsresult rv;

    if (LSHE) {
        /* You get here if you are currently building a 
         * hierarchy ie.,you just visited a frameset page
         */
        nsCOMPtr<nsISHContainer> container(do_QueryInterface(LSHE, &rv));
        if (container) {
            rv = container->AddChild(aNewEntry, aChildOffset);
        }
    }
    else if (mSessionHistory) {
        /* You are currently in the rootDocShell.
         * You will get here when a subframe has a new url
         * to load and you have walked up the tree all the 
         * way to the top to clone the current SHEntry hierarchy
         * and replace the subframe where a new url was loaded with
         * a new entry.
         */
        PRInt32 index = -1;
        nsCOMPtr<nsIHistoryEntry> currentHE;
        mSessionHistory->GetIndex(&index);
        if (index < 0)
            return NS_ERROR_FAILURE;

        rv = mSessionHistory->GetEntryAtIndex(index, PR_FALSE,
                                              getter_AddRefs(currentHE));
        NS_ENSURE_TRUE(currentHE, NS_ERROR_FAILURE);

        nsCOMPtr<nsISHEntry> currentEntry(do_QueryInterface(currentHE));
        if (currentEntry) {
            PRUint32 cloneID = 0;
            nsCOMPtr<nsISHEntry> nextEntry;  //(do_CreateInstance(NS_SHENTRY_CONTRACTID));
            //   NS_ENSURE_TRUE(result, NS_ERROR_FAILURE);
            if (aCloneRef)
                aCloneRef->GetID(&cloneID);
            rv = CloneAndReplace(currentEntry, cloneID, aNewEntry,
                                 getter_AddRefs(nextEntry));

            if (NS_SUCCEEDED(rv)) {
                nsCOMPtr<nsISHistoryInternal>
                    shPrivate(do_QueryInterface(mSessionHistory));
                NS_ENSURE_TRUE(shPrivate, NS_ERROR_FAILURE);
                rv = shPrivate->AddEntry(nextEntry, PR_TRUE);
            }
        }
    }
    else {
        /* You will get here when you are in a subframe and
         * a new url has been loaded on you. 
         * The OSHE in this subframe will be the previous url's
         * OSHE. This OSHE will be used as the identification
         * for this subframe in the  CloneAndReplace function.
         */

        nsCOMPtr<nsIDocShellHistory> parent(do_QueryInterface(mParent, &rv));
        if (parent) {
            if (!aCloneRef) {
                aCloneRef = OSHE;
            }
            rv = parent->AddChildSHEntry(aCloneRef, aNewEntry, aChildOffset);
        }

    }
    return rv;
}

NS_IMETHODIMP
nsDocShell::SetGlobalHistory(nsIGlobalHistory * aGlobalHistory)
{
    mGlobalHistory = aGlobalHistory;
    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::GetGlobalHistory(nsIGlobalHistory ** aGlobalHistory)
{
    NS_ENSURE_ARG_POINTER(aGlobalHistory);

    *aGlobalHistory = mGlobalHistory;
    NS_IF_ADDREF(*aGlobalHistory);
    return NS_OK;
}

//*****************************************************************************
// nsDocShell::nsIWebNavigation
//*****************************************************************************   

NS_IMETHODIMP
nsDocShell::GetCanGoBack(PRBool * aCanGoBack)
{
    nsCOMPtr<nsIDocShellTreeItem> root;
    //Get the root docshell
    GetSameTypeRootTreeItem(getter_AddRefs(root));
    NS_ENSURE_TRUE(root, NS_ERROR_FAILURE);
    // QI to nsIWebNavigation
    nsCOMPtr<nsIWebNavigation> rootAsWebnav(do_QueryInterface(root));
    if (rootAsWebnav) {
        // Get the handle to SH from the root docshell
        nsCOMPtr<nsISHistory> rootSH;
        rootAsWebnav->GetSessionHistory(getter_AddRefs(rootSH));
        NS_ENSURE_TRUE(rootSH, NS_ERROR_FAILURE);
        // QI SH to nsIWebNavigation
        nsCOMPtr<nsIWebNavigation> webNav(do_QueryInterface(rootSH));
        if (webNav)
            return webNav->GetCanGoBack(aCanGoBack);
    }
    return NS_ERROR_FAILURE;

}

NS_IMETHODIMP
nsDocShell::GetCanGoForward(PRBool * aCanGoForward)
{
    nsCOMPtr<nsIDocShellTreeItem> root;
    //Get the root docshell
    GetSameTypeRootTreeItem(getter_AddRefs(root));
    NS_ENSURE_TRUE(root, NS_ERROR_FAILURE);
    // QI to nsIWebNavigation
    nsCOMPtr<nsIWebNavigation> rootAsWebnav(do_QueryInterface(root));
    if (rootAsWebnav) {
        // Get the handle to SH from the root docshell
        nsCOMPtr<nsISHistory> rootSH;
        rootAsWebnav->GetSessionHistory(getter_AddRefs(rootSH));
        NS_ENSURE_TRUE(rootSH, NS_ERROR_FAILURE);
        // QI SH to nsIWebNavigation
        nsCOMPtr<nsIWebNavigation> webNav(do_QueryInterface(rootSH));
        if (webNav)
            return webNav->GetCanGoForward(aCanGoForward);
    }
    return NS_ERROR_FAILURE;

}

NS_IMETHODIMP
nsDocShell::GoBack()
{
    nsCOMPtr<nsIDocShellTreeItem> root;
    //Get the root docshell
    GetSameTypeRootTreeItem(getter_AddRefs(root));
    NS_ENSURE_TRUE(root, NS_ERROR_FAILURE);
    // QI to nsIWebNavigation
    nsCOMPtr<nsIWebNavigation> rootAsWebnav(do_QueryInterface(root));
    if (rootAsWebnav) {
        // Get the handle to SH from the root docshell
        nsCOMPtr<nsISHistory> rootSH;
        rootAsWebnav->GetSessionHistory(getter_AddRefs(rootSH));
        NS_ENSURE_TRUE(rootSH, NS_ERROR_FAILURE);
        // QI SH to nsIWebNavigation
        nsCOMPtr<nsIWebNavigation> webNav(do_QueryInterface(rootSH));
        if (webNav)
            return webNav->GoBack();
    }
    return NS_ERROR_FAILURE;

}

NS_IMETHODIMP
nsDocShell::GoForward()
{
    nsCOMPtr<nsIDocShellTreeItem> root;
    //Get the root docshell
    GetSameTypeRootTreeItem(getter_AddRefs(root));
    NS_ENSURE_TRUE(root, NS_ERROR_FAILURE);
    // QI to nsIWebNavigation
    nsCOMPtr<nsIWebNavigation> rootAsWebnav(do_QueryInterface(root));
    if (rootAsWebnav) {
        // Get the handle to SH from the root docshell
        nsCOMPtr<nsISHistory> rootSH;
        rootAsWebnav->GetSessionHistory(getter_AddRefs(rootSH));
        NS_ENSURE_TRUE(rootSH, NS_ERROR_FAILURE);
        // QI SH to nsIWebNavigation
        nsCOMPtr<nsIWebNavigation> webNav(do_QueryInterface(rootSH));
        if (webNav)
            return webNav->GoForward();
    }
    return NS_ERROR_FAILURE;

}

NS_IMETHODIMP nsDocShell::GotoIndex(PRInt32 aIndex)
{
    nsCOMPtr<nsIDocShellTreeItem> root;
    //Get the root docshell
    GetSameTypeRootTreeItem(getter_AddRefs(root));
    NS_ENSURE_TRUE(root, NS_ERROR_FAILURE);
    // QI to nsIWebNavigation
    nsCOMPtr<nsIWebNavigation> rootAsWebnav(do_QueryInterface(root));
    if (rootAsWebnav) {
        // Get the handle to SH from the root docshell
        nsCOMPtr<nsISHistory> rootSH;
        rootAsWebnav->GetSessionHistory(getter_AddRefs(rootSH));
        NS_ENSURE_TRUE(rootSH, NS_ERROR_FAILURE);
        // QI SH to nsIWebNavigation
        nsCOMPtr<nsIWebNavigation> webNav(do_QueryInterface(rootSH));
        if (webNav)
            return webNav->GotoIndex(aIndex);
    }
    return NS_ERROR_FAILURE;

}


NS_IMETHODIMP
nsDocShell::LoadURI(const PRUnichar * aURI, PRUint32 aLoadFlags)
{
    nsCOMPtr<nsIURI> uri;

    nsresult rv = CreateFixupURI(aURI, getter_AddRefs(uri));

    if (NS_ERROR_UNKNOWN_PROTOCOL == rv) {
        // we weren't able to find a protocol handler
        nsCOMPtr<nsIPrompt> prompter;
        nsCOMPtr<nsIStringBundle> stringBundle;
        GetPromptAndStringBundle(getter_AddRefs(prompter),
                                 getter_AddRefs(stringBundle));

        NS_ENSURE_TRUE(stringBundle, NS_ERROR_FAILURE);

        nsXPIDLString messageStr;
        NS_ENSURE_SUCCESS(stringBundle->
                          GetStringFromName(NS_ConvertASCIItoUCS2
                                            ("protocolNotFound").GetUnicode(),
                                            getter_Copies(messageStr)),
                          NS_ERROR_FAILURE);

        nsAutoString uriString(aURI);
        PRInt32 colon = uriString.FindChar(':');
        // extract the scheme
        nsAutoString scheme;
        uriString.Left(scheme, colon);
        nsCAutoString cScheme;
        cScheme.AssignWithConversion(scheme);

        PRUnichar *msg = nsTextFormatter::smprintf(messageStr, cScheme.get());
        if (!msg)
            return NS_ERROR_OUT_OF_MEMORY;

        prompter->Alert(nsnull, msg);
        nsTextFormatter::smprintf_free(msg);
    }                           // end unknown protocol

    if (!uri)
        return NS_ERROR_FAILURE;

    NS_ENSURE_SUCCESS(LoadURI(uri, nsnull, aLoadFlags), NS_ERROR_FAILURE);
    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::Reload(PRUint32 aReloadFlags)
{
    NS_ASSERTION(((aReloadFlags & 0xf) == 0),
                 "Reload command not updated to use load flags!");

    // XXXTAB Convert reload type to our type
    LoadType type = LOAD_RELOAD_NORMAL;
    if (aReloadFlags & LOAD_FLAGS_BYPASS_CACHE &&
        aReloadFlags & LOAD_FLAGS_BYPASS_PROXY)
        type = LOAD_RELOAD_BYPASS_PROXY_AND_CACHE;

    nsresult rv;
    /* If you change this part of code, make sure bug 45297 does not re-occur */
    if (OSHE)
        rv = LoadHistoryEntry(OSHE, type);
    else if (LSHE)              // In case a reload happened before the current load is done
        rv = LoadHistoryEntry(LSHE, type);
    else
        rv = InternalLoad(mCurrentURI, mReferrerURI, nsnull, PR_TRUE, PR_FALSE,
                          nsnull, nsnull, nsnull, type);
    return rv;
}

NS_IMETHODIMP
nsDocShell::Stop()
{
    // Cancel any timers that were set for this loader.
    CancelRefreshURITimers();

    if (mContentViewer)
        mContentViewer->Stop();

    if (mLoadCookie) {
        nsCOMPtr<nsIURILoader> uriLoader =
            do_GetService(NS_URI_LOADER_CONTRACTID);
        if (uriLoader)
            uriLoader->Stop(mLoadCookie);
    }

    PRInt32 n;
    PRInt32 count = mChildren.Count();
    for (n = 0; n < count; n++) {
        nsIDocShellTreeItem *shell =
            (nsIDocShellTreeItem *) mChildren.ElementAt(n);
        nsCOMPtr<nsIWebNavigation> shellAsNav(do_QueryInterface(shell));
        if (shellAsNav)
            shellAsNav->Stop();
    }

    return NS_OK;
}

/*
NS_IMETHODIMP nsDocShell::SetDocument(nsIDOMDocument* aDocument,
   const PRUnichar* aContentType)
{
   //XXX First Checkin
   NS_ERROR("Not Yet Implemented");
   return NS_ERROR_FAILURE;
}
*/

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

    return mContentViewer->GetDOMDocument(aDocument);
}

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

    *aURI = mCurrentURI;
    NS_IF_ADDREF(*aURI);

    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::SetSessionHistory(nsISHistory * aSessionHistory)
{

    NS_ENSURE_TRUE(aSessionHistory, NS_ERROR_FAILURE);
    // make sure that we are the root docshell and
    // set a handle to root docshell in SH.

    nsCOMPtr<nsIDocShellTreeItem> root;
    /* Get the root docshell. If *this* is the root docshell
     * then save a handle to *this* in SH. SH needs it to do
     * traversions thro' its entries
     */
    GetSameTypeRootTreeItem(getter_AddRefs(root));
    NS_ENSURE_TRUE(root, NS_ERROR_FAILURE);
    if (root.get() == NS_STATIC_CAST(nsIDocShellTreeItem *, this)) {
        mSessionHistory = aSessionHistory;
        nsCOMPtr<nsISHistoryInternal>
            shPrivate(do_QueryInterface(mSessionHistory));
        NS_ENSURE_TRUE(shPrivate, NS_ERROR_FAILURE);
        shPrivate->SetRootDocShell(this);
        return NS_OK;
    }
    return NS_ERROR_FAILURE;

}

NS_IMETHODIMP
nsDocShell::GetSessionHistory(nsISHistory ** aSessionHistory)
{
    NS_ENSURE_ARG_POINTER(aSessionHistory);
    if (mSessionHistory) {
        *aSessionHistory = mSessionHistory;
        NS_IF_ADDREF(*aSessionHistory);
        return NS_OK;
    }

    return NS_ERROR_FAILURE;

}

//*****************************************************************************
// 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

    SetParentWidget(parentWidget);
    SetPositionAndSize(x, y, cx, cy, PR_FALSE);

    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::Create()
{
    NS_ENSURE_STATE(!mContentViewer);
    mPrefs = do_GetService(NS_PREF_CONTRACTID);
    //GlobalHistory is now set in SetGlobalHistory
    //  mGlobalHistory = do_GetService(NS_GLOBALHISTORY_CONTRACTID);

    // i don't want to read this pref in every time we load a url
    // so read it in once here and be done with it...
    mPrefs->GetBoolPref("network.protocols.useSystemDefaults",
                        &mUseExternalProtocolHandler);
    mPrefs->GetBoolPref("browser.target_new_blocked", &mDisallowPopupWindows);
    mPrefs->GetBoolPref("browser.frames.enabled", &mAllowSubframes);

    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::Destroy()
{
    // Stop any URLs that are currently being loaded...
    Stop();
    if (mDocLoader) {
        mDocLoader->Destroy();
        mDocLoader->SetContainer(nsnull);
    }

    SetDocLoaderObserver(nsnull);

    // Save the state of the current document, before destroying the window.
    // This is needed to capture the state of a frameset when the new document
    // causes the frameset to be destroyed...
    PersistLayoutHistoryState();

    // Remove this docshell from its parent's child list
    nsCOMPtr<nsIDocShellTreeNode>
        docShellParentAsNode(do_QueryInterface(mParent));
    if (docShellParentAsNode)
        docShellParentAsNode->RemoveChild(this);

    if (mScriptGlobal) {
        nsCOMPtr<nsIFocusController> focusController;
        nsCOMPtr<nsPIDOMWindow> ourWindow = do_QueryInterface(mScriptGlobal);
        ourWindow->GetRootFocusController(getter_AddRefs(focusController));
        if (focusController) {
            focusController->SetFocusedWindow(nsnull);
        }
    }

    if (mContentViewer) {
        mContentViewer->Destroy();
        mContentViewer = nsnull;
    }

    DestroyChildren();

    mDocLoader = nsnull;
    mDocLoaderObserver = nsnull;
    mParentWidget = nsnull;
    mPrefs = nsnull;
    mCurrentURI = nsnull;

    if (mScriptGlobal) {
        mScriptGlobal->SetDocShell(nsnull);
        mScriptGlobal = nsnull;
    }
    if (mScriptContext) {
        mScriptContext->SetOwner(nsnull);
        mScriptContext = nsnull;
    }

    mSessionHistory = nsnull;
    SetTreeOwner(nsnull);

    SetLoadCookie(nsnull);

    if (mInitInfo) {
        delete mInitInfo;
        mInitInfo = nsnull;
    }

    if (mContentListener) {
        mContentListener->DocShell(nsnull);
        NS_RELEASE(mContentListener);
    }

    return NS_OK;
}

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 aCX, PRInt32 aCY, PRBool aRepaint)
{
    PRInt32 x = 0, y = 0;
    GetPosition(&x, &y);
    return SetPositionAndSize(x, y, aCX, aCY, aRepaint);
}

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)
{
    if (mContentViewer) {
        nsRect bounds;

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

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

    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::Repaint(PRBool aForce)
{
    nsCOMPtr<nsIDocumentViewer> docViewer(do_QueryInterface(mContentViewer));
    NS_ENSURE_TRUE(docViewer, NS_ERROR_FAILURE);

    nsCOMPtr<nsIPresContext> context;
    docViewer->GetPresContext(*getter_AddRefs(context));
    NS_ENSURE_TRUE(context, NS_ERROR_FAILURE);

    nsCOMPtr<nsIPresShell> shell;
    context->GetShell(getter_AddRefs(shell));
    NS_ENSURE_TRUE(shell, NS_ERROR_FAILURE);

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

    // what about aForce ?
    NS_ENSURE_SUCCESS(viewManager->UpdateAllViews(0), NS_ERROR_FAILURE);
    return NS_OK;
}

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 * aParentWidget)
{
    NS_ENSURE_STATE(!mContentViewer);

    mParentWidget = aParentWidget;

    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 (!mContentViewer) {
        *aVisibility = PR_FALSE;
        return NS_OK;
    }

    // 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);
    *aVisibility = nsViewVisibility_kHide == vis ? PR_FALSE : PR_TRUE;

    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::SetVisibility(PRBool aVisibility)
{
    if (!mContentViewer)
        return NS_OK;
    if (aVisibility) {
        NS_ENSURE_SUCCESS(EnsureContentViewer(), NS_ERROR_FAILURE);
        mContentViewer->Show();
    }
    else if (mContentViewer)
        mContentViewer->Hide();

    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::GetMainWidget(nsIWidget ** aMainWidget)
{
    // We don't create our own widget, so simply return the parent one. 
    return GetParentWidget(aMainWidget);
}

NS_IMETHODIMP
nsDocShell::SetFocus()
{
    nsCOMPtr<nsIPresShell> presShell;
    nsCOMPtr<nsIDocument> document;
    GetPresShell(getter_AddRefs(presShell));
    if (!presShell)
        return NS_ERROR_FAILURE;
    presShell->GetDocument(getter_AddRefs(document));

    nsCOMPtr<nsIPresContext> presContext;
    GetPresContext(getter_AddRefs(presContext));
    if (!presContext)
        return NS_ERROR_FAILURE;

    nsCOMPtr<nsIEventStateManager> esm;
    presContext->GetEventStateManager(getter_AddRefs(esm));
    if (!esm)
        return NS_ERROR_FAILURE;

    nsCOMPtr<nsIContent>
        rootContent(getter_AddRefs(document->GetRootContent()));
    if (!rootContent)
        return NS_ERROR_FAILURE;

    nsCOMPtr<nsIContent> focusContent;
    esm->GetNextTabbableContent(rootContent, nsnull, PR_TRUE,
                                getter_AddRefs(focusContent));
    if (focusContent) {
        nsIFrame *focusFrame = nsnull;
        presShell->GetPrimaryFrameFor(focusContent, &focusFrame);
        esm->ChangeFocus(focusContent, focusFrame, PR_TRUE);
    } else {
        nsCOMPtr<nsIScriptGlobalObject> sgo;
        document->GetScriptGlobalObject(getter_AddRefs(sgo));
        if (sgo) {
            nsCOMPtr<nsIDOMWindowInternal> domwin(do_QueryInterface(sgo));
            if (domwin)
                domwin->Focus();
        }
    }

    return NS_OK;
}

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

    nsresult ret;

    // Are we embedded?

    nsCOMPtr<nsIWebBrowserChromeFocus>
        chromeFocus(do_GetInterface(mTreeOwner, &ret));
    if (chromeFocus) {
#ifdef DEBUG_dr
        printf("dr :: nsDocShell::FocusAvailable, embedded\n");
#endif
        if (aForward)
            ret = chromeFocus->FocusNextElement();
        else
            ret = chromeFocus->FocusPrevElement();
        return ret;
    }

    // Otherwise, first person we should call is the parent, or the 
    // docshell tree owner.
    nsCOMPtr<nsIBaseWindow> nextCallWin(do_QueryInterface(mParent));
    if (!nextCallWin)
        nextCallWin = do_QueryInterface(mTreeOwner);

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

        if (!mChildren.Count()) {
            //If we don't have children and our parent didn't want 
            //the focus then we should just stop now.
            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 we have focus we offer it to our first child.
        if (aCurrentFocus == NS_STATIC_CAST(nsIBaseWindow *, this)) {
            if (NS_SUCCEEDED(child->SetFocus())) {
                *aTookFocus = PR_TRUE;
                return NS_OK;
            }
            else
                return NS_ERROR_FAILURE;
        }
        //If we don't have focus, find the child that does then
        //offer focus to the next one.
        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;
                }
                else
                    return NS_ERROR_FAILURE;
            }
        }
    }

    //Reached the end of our child list.  If we aren't currently focused, try
    // to accept focus.

    if ((aCurrentFocus != NS_STATIC_CAST(nsIBaseWindow *, this)) &&
        NS_SUCCEEDED(SetFocus())) {
        *aTookFocus = PR_TRUE;
        return NS_OK;
    }

    // Call again to offer focus upwards and to start at the beginning of our
    // child list if no one above us wants focus.
    return FocusAvailable(this, aForward, aTookFocus);
}

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)
            treeOwnerAsWin->SetTitle(aTitle);
    }

    if (mGlobalHistory && mCurrentURI) {
        nsXPIDLCString url;
        mCurrentURI->GetSpec(getter_Copies(url));
        nsCOMPtr<nsIBrowserHistory> browserHistory =
            do_QueryInterface(mGlobalHistory);
        browserHistory->SetPageTitle(url, aTitle);
    }


    // Update SessionHistory too with Title. Otherwise entry for current page
    // has previous page's title.
    if (mSessionHistory) {
        PRInt32 index = -1;
        mSessionHistory->GetIndex(&index);
        nsCOMPtr<nsIHistoryEntry> hEntry;
        mSessionHistory->GetEntryAtIndex(index, PR_FALSE,
                                         getter_AddRefs(hEntry));
        NS_ENSURE_TRUE(hEntry, NS_ERROR_FAILURE);
        nsCOMPtr<nsISHEntry> shEntry(do_QueryInterface(hEntry));
        if (shEntry)
            shEntry->SetTitle(mTitle.GetUnicode());
    }


    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);
    if (!scrollView) {
        return 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);
    if (!scrollView) {
        return 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);
        x = 0;
        y = 0;                  // fix compiler warning, not actually executed
    }

    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);
    if (!scrollView) {
        return 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);
    if (!scrollView) {
        return 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;
}

// Get scroll setting for this document only
//
// One important client is nsCSSFrameConstructor::ConstructRootFrame()
NS_IMETHODIMP
nsDocShell::GetCurrentScrollbarPreferences(PRInt32 scrollOrientation,
                                           PRInt32 * scrollbarPref)
{
    NS_ENSURE_ARG_POINTER(scrollbarPref);
    switch (scrollOrientation) {
    case ScrollOrientation_X:
        *scrollbarPref = mCurrentScrollbarPref.x;
        return NS_OK;

    case ScrollOrientation_Y:
        *scrollbarPref = mCurrentScrollbarPref.y;
        return NS_OK;

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

// This returns setting for all documents in this webshell
NS_IMETHODIMP
nsDocShell::GetDefaultScrollbarPreferences(PRInt32 scrollOrientation,
                                           PRInt32 * scrollbarPref)
{
    NS_ENSURE_ARG_POINTER(scrollbarPref);
    switch (scrollOrientation) {
    case ScrollOrientation_X:
        *scrollbarPref = mDefaultScrollbarPref.x;
        return NS_OK;

    case ScrollOrientation_Y:
        *scrollbarPref = mDefaultScrollbarPref.y;
        return NS_OK;

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

// Set scrolling preference for this document only.
//
// There are three possible values stored in the shell:
//  1) NS_STYLE_OVERFLOW_HIDDEN = no scrollbars
//  2) NS_STYLE_OVERFLOW_AUTO = scrollbars appear if needed
//  3) NS_STYLE_OVERFLOW_SCROLL = scrollbars always
//
// XXX Currently OVERFLOW_SCROLL isn't honored,
//     as it is not implemented by Gfx scrollbars
// XXX setting has no effect after the root frame is created
//     as it is not implemented by Gfx scrollbars
//
// One important client is HTMLContentSink::StartLayout()
NS_IMETHODIMP
nsDocShell::SetCurrentScrollbarPreferences(PRInt32 scrollOrientation,
                                           PRInt32 scrollbarPref)
{
    switch (scrollOrientation) {
    case ScrollOrientation_X:
        mCurrentScrollbarPref.x = scrollbarPref;
        return NS_OK;

    case ScrollOrientation_Y:
        mCurrentScrollbarPref.y = scrollbarPref;
        return NS_OK;

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

// Set scrolling preference for all documents in this shell
// One important client is nsHTMLFrameInnerFrame::CreateWebShell()
NS_IMETHODIMP
nsDocShell::SetDefaultScrollbarPreferences(PRInt32 scrollOrientation,
                                           PRInt32 scrollbarPref)
{
    switch (scrollOrientation) {
    case ScrollOrientation_X:
        mDefaultScrollbarPref.x = scrollbarPref;
        return NS_OK;

    case ScrollOrientation_Y:
        mDefaultScrollbarPref.y = scrollbarPref;
        return NS_OK;

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

// Reset 'current' scrollbar settings to 'default'.
// This must be called before every document load or else
// frameset scrollbar settings (e.g. <IFRAME SCROLLING="no">
// will not be preserved.
//
// One important client is HTMLContentSink::StartLayout()
NS_IMETHODIMP
nsDocShell::ResetScrollbarPreferences()
{
    mCurrentScrollbarPref = mDefaultScrollbarPref;
    return NS_OK;
}

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

    NS_ENSURE_SUCCESS(scrollView->ScrollByLines(0, 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);
    if (!scrollView) {
        return NS_ERROR_FAILURE;
    }

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

    return NS_OK;
}

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

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

    *aGlobal = mScriptGlobal;
    NS_IF_ADDREF(*aGlobal);
    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::ReportScriptError(nsIScriptError * errorObject)
{
    nsresult rv;

    if (errorObject == nsnull)
        return NS_ERROR_NULL_POINTER;

    // Get the console service, where we're going to register the error.
    nsCOMPtr<nsIConsoleService> consoleService
        (do_GetService("@mozilla.org/consoleservice;1"));

    if (consoleService != nsnull) {
        rv = consoleService->LogMessage(errorObject);
        if (NS_SUCCEEDED(rv)) {
            return NS_OK;
        }
        else {
            return rv;
        }
    }
    else {
        return NS_ERROR_NOT_AVAILABLE;
    }
}

//*****************************************************************************
// nsDocShell::nsIRefreshURI
//*****************************************************************************   

NS_IMETHODIMP
nsDocShell::RefreshURI(nsIURI * aURI, PRInt32 aDelay, PRBool aRepeat,
                       PRBool aMetaRefresh)
{
    NS_ENSURE_ARG(aURI);

    nsRefreshTimer *refreshTimer = new nsRefreshTimer();
    NS_ENSURE_TRUE(refreshTimer, NS_ERROR_OUT_OF_MEMORY);

    nsCOMPtr<nsISupports> dataRef = refreshTimer;    // Get the ref count to 1

    refreshTimer->mDocShell = this;
    refreshTimer->mURI = aURI;
    refreshTimer->mDelay = aDelay;
    refreshTimer->mRepeat = aRepeat;
    refreshTimer->mMetaRefresh = aMetaRefresh;

    if (!mRefreshURIList) {
        NS_ENSURE_SUCCESS(NS_NewISupportsArray(getter_AddRefs(mRefreshURIList)),
                          NS_ERROR_FAILURE);
    }

    nsCOMPtr<nsITimer> timer = do_CreateInstance("@mozilla.org/timer;1");
    NS_ENSURE_TRUE(timer, NS_ERROR_FAILURE);

    mRefreshURIList->AppendElement(timer);      // owning timer ref
    timer->Init(refreshTimer, aDelay);

    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::CancelRefreshURITimers()
{
    if (!mRefreshURIList)
        return NS_OK;

    PRUint32 n;
    mRefreshURIList->Count(&n);

    while (n) {
        nsCOMPtr<nsISupports> element;
        mRefreshURIList->GetElementAt(0, getter_AddRefs(element));
        nsCOMPtr<nsITimer> timer(do_QueryInterface(element));

        mRefreshURIList->RemoveElementAt(0);    // bye bye owning timer ref

        if (timer)
            timer->Cancel();
        n--;
    }

    return NS_OK;
}

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

NS_IMETHODIMP
nsDocShell::Embed(nsIContentViewer * aContentViewer,
                  const char *aCommand, nsISupports * aExtraInfo)
{
    // Save the LayoutHistoryState of the previous document, before
    // setting up new document
    PersistLayoutHistoryState();

    nsresult rv = SetupNewViewer(aContentViewer);

    // XXX What if SetupNewViewer fails?

    OSHE = LSHE;

    PRBool updateHistory = PR_TRUE;

    // Determine if this type of load should update history   
    switch (mLoadType) {
    case LOAD_NORMAL_REPLACE:
    case LOAD_RELOAD_BYPASS_CACHE:
    case LOAD_RELOAD_BYPASS_PROXY:
    case LOAD_RELOAD_BYPASS_PROXY_AND_CACHE:
        updateHistory = PR_FALSE;
        break;
    default:
        break;
    }

    if (OSHE && updateHistory) {
        nsCOMPtr<nsILayoutHistoryState> layoutState;

        rv = OSHE->GetLayoutHistoryState(getter_AddRefs(layoutState));
        if (layoutState) {
            // This is a SH load. That's why there is a LayoutHistoryState in OSHE
            nsCOMPtr<nsIPresShell> presShell;
            rv = GetPresShell(getter_AddRefs(presShell));
            if (NS_SUCCEEDED(rv) && presShell) {
                rv = presShell->SetHistoryState(layoutState);
            }
        }
    }
    return NS_OK;
}

//*****************************************************************************
// nsDocShell::nsIWebProgressListener
//*****************************************************************************   

NS_IMETHODIMP
nsDocShell::OnProgressChange(nsIWebProgress * aProgress,
                             nsIRequest * aRequest,
                             PRInt32 aCurSelfProgress,
                             PRInt32 aMaxSelfProgress,
                             PRInt32 aCurTotalProgress,
                             PRInt32 aMaxTotalProgress)
{
    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::OnStateChange(nsIWebProgress * aProgress, nsIRequest * aRequest,
                          PRInt32 aStateFlags, nsresult aStatus)
{
    // Update the busy cursor
    if ((~aStateFlags & (STATE_START | STATE_IS_NETWORK)) == 0) {
        // Page has begun to load
        mBusyFlags = BUSY_FLAGS_BUSY | BUSY_FLAGS_BEFORE_PAGE_LOAD;
        nsCOMPtr<nsIWidget> mainWidget;
        GetMainWidget(getter_AddRefs(mainWidget));
        if (mainWidget) {
            mainWidget->SetCursor(eCursor_spinning);
        }
    }
    else if ((~aStateFlags & (STATE_TRANSFERRING | STATE_IS_DOCUMENT)) == 0) {
        // Page is loading
        mBusyFlags = BUSY_FLAGS_BUSY | BUSY_FLAGS_PAGE_LOADING;
    }
    else if ((aStateFlags & STATE_STOP) && (aStateFlags & STATE_IS_NETWORK)) {
        // Page has finished loading
        mBusyFlags = BUSY_FLAGS_NONE;
        nsCOMPtr<nsIWidget> mainWidget;
        GetMainWidget(getter_AddRefs(mainWidget));
        if (mainWidget) {
            mainWidget->SetCursor(eCursor_standard);
        }
    }

    if ((~aStateFlags & (STATE_IS_DOCUMENT | STATE_STOP)) == 0) {
        nsCOMPtr<nsIWebProgress> webProgress(do_QueryInterface(mLoadCookie));

        // Is the document stop notification for this document?
        if (aProgress == webProgress.get()) {
            nsCOMPtr<nsIChannel> channel(do_QueryInterface(aRequest));

            EndPageLoad(aProgress, channel, aStatus);
        }
    }
    else if ((~aStateFlags & (STATE_IS_DOCUMENT | STATE_REDIRECTING)) == 0) {
        // XXX Is it enough if I check just for the above 2 flags for redirection 
        nsCOMPtr<nsIWebProgress> webProgress(do_QueryInterface(mLoadCookie));

        // Is the document stop notification for this document?
        if (aProgress == webProgress.get()) {
            nsCOMPtr<nsIChannel> channel(do_QueryInterface(aRequest));
            if (channel) {
                // Get the uri from the channel
                nsCOMPtr<nsIURI> uri;
                channel->GetURI(getter_AddRefs(uri));
                // Add the original url to global History so that
                // visited url color changes happen.
                if (uri) {
                    // Update Global history if necessary...
                    PRBool updateHistory = PR_FALSE;
                    ShouldAddToGlobalHistory(uri, &updateHistory);
                    if (updateHistory) {
                        AddToGlobalHistory(uri);
                    }
                }               // uri
            }                   // channel
        }                       // aProgress
    }
    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::OnLocationChange(nsIWebProgress * aProgress,
                             nsIRequest * aRequest, nsIURI * aURI)
{
    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::OnStatusChange(nsIWebProgress * aWebProgress,
                           nsIRequest * aRequest,
                           nsresult aStatus, const PRUnichar * aMessage)
{
    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::OnSecurityChange(nsIWebProgress * aWebProgress,
                             nsIRequest * aRequest, PRInt32 state)
{
    return NS_ERROR_NOT_IMPLEMENTED;
}


nsresult
nsDocShell::EndPageLoad(nsIWebProgress * aProgress,
                        nsIChannel * aChannel, nsresult aStatus)
{
    if (LSHE) {
        LSHE->SetLoadType(nsIDocShellLoadInfo::loadHistory);

        // Clear the LSHE reference to indicate document loading is done one
        // way or another.
        LSHE = nsnull;
    }

    //
    // one of many safeguards that prevent death and destruction if
    // someone is so very very rude as to bring this window down
    // during this load handler.
    //
    nsCOMPtr<nsIDocShell> kungFuDeathGrip(this);
    //
    // Notify the ContentViewer that the Document has finished loading...
    //
    // This will cause any OnLoad(...) handlers to fire, if it is a HTML
    // document...
    //
    if (!mEODForCurrentDocument && mContentViewer) {
        mContentViewer->LoadComplete(aStatus);

        mEODForCurrentDocument = PR_TRUE;
    }
    return NS_OK;
}


//*****************************************************************************
// nsDocShell: Content Viewer Management
//*****************************************************************************   

NS_IMETHODIMP
nsDocShell::EnsureContentViewer()
{
    if (mContentViewer)
        return NS_OK;

    return CreateAboutBlankContentViewer();
}

NS_IMETHODIMP
nsDocShell::EnsureDeviceContext()
{
    if (mDeviceContext)
        return NS_OK;

    mDeviceContext = do_CreateInstance(kDeviceContextCID);
    NS_ENSURE_TRUE(mDeviceContext, NS_ERROR_FAILURE);

    nsCOMPtr<nsIWidget> widget;
    GetMainWidget(getter_AddRefs(widget));
    NS_ENSURE_TRUE(widget, NS_ERROR_FAILURE);

    mDeviceContext->Init(widget->GetNativeData(NS_NATIVE_WIDGET));
    float dev2twip;
    mDeviceContext->GetDevUnitsToTwips(dev2twip);
    mDeviceContext->SetDevUnitsToAppUnits(dev2twip);
    float twip2dev;
    mDeviceContext->GetTwipsToDevUnits(twip2dev);
    mDeviceContext->SetAppUnitsToDevUnits(twip2dev);
    mDeviceContext->SetGamma(1.0f);

    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::CreateAboutBlankContentViewer()
{
    // XXX
    NS_ERROR("Not Implemented yet");
    return NS_ERROR_FAILURE;
}

NS_IMETHODIMP
nsDocShell::CreateContentViewer(const char *aContentType,
                                nsIRequest * request,
                                nsIStreamListener ** aContentHandler)
{
    // Can we check the content type of the current content viewer
    // and reuse it without destroying it and re-creating it?

    nsCOMPtr<nsILoadGroup> loadGroup(do_GetInterface(mLoadCookie));
    NS_ENSURE_TRUE(loadGroup, NS_ERROR_FAILURE);

    // Instantiate the content viewer object
    nsCOMPtr<nsIContentViewer> viewer;
    nsresult rv = NewContentViewerObj(aContentType, request, loadGroup,
                                      aContentHandler, getter_AddRefs(viewer));

    if (NS_FAILED(rv))
        return NS_ERROR_FAILURE;

    // we've created a new document so go ahead and call OnLoadingSite
    mURIResultedInDocument = PR_TRUE;

    nsCOMPtr<nsIChannel> aOpenedChannel = do_QueryInterface(request);

    OnLoadingSite(aOpenedChannel);

    // let's try resetting the load group if we need to...
    nsCOMPtr<nsILoadGroup> currentLoadGroup;
    NS_ENSURE_SUCCESS(aOpenedChannel->
                      GetLoadGroup(getter_AddRefs(currentLoadGroup)),
                      NS_ERROR_FAILURE);

    if (currentLoadGroup.get() != loadGroup.get()) {
        nsLoadFlags loadFlags = 0;

        //Cancel any URIs that are currently loading...
        /// XXX: Need to do this eventually      Stop();
        //
        // Retarget the document to this loadgroup...
        //
        /* First attach the channel to the right loadgroup
         * and then remove from the old loadgroup. This 
         * puts the notifications in the right order and
         * we don't null-out LSHE in OnStateChange() for 
         * all redirected urls
         */
        aOpenedChannel->SetLoadGroup(loadGroup);

        // Mark the channel as being a document URI...
        aOpenedChannel->GetLoadFlags(&loadFlags);
        loadFlags |= nsIChannel::LOAD_DOCUMENT_URI;

        aOpenedChannel->SetLoadFlags(loadFlags);

        loadGroup->AddRequest(request, nsnull);
        if (currentLoadGroup)
            currentLoadGroup->RemoveRequest(request, nsnull, NS_OK);

    }

    NS_ENSURE_SUCCESS(Embed(viewer, "", (nsISupports *) nsnull),
                      NS_ERROR_FAILURE);

    mEODForCurrentDocument = PR_FALSE;  // clear the current flag
    return NS_OK;
}

nsresult
nsDocShell::NewContentViewerObj(const char *aContentType,
                                nsIRequest * request, nsILoadGroup * aLoadGroup,
                                nsIStreamListener ** aContentHandler,
                                nsIContentViewer ** aViewer)
{
    //XXX This should probably be some category thing....
    char id[256];
    PR_snprintf(id, sizeof(id),
                NS_DOCUMENT_LOADER_FACTORY_CONTRACTID_PREFIX "%s;1?type=%s",
                (const char *) "view", aContentType);

    // Note that we're always passing in "view" for the component id above
    // and to the docLoaderFactory->CreateInstance() at the end of this method. 
    // nsLayoutDLF makes the determination if it should be a "view-source"

    // Create an instance of the document-loader-factory
    nsCOMPtr<nsIDocumentLoaderFactory>
        docLoaderFactory(do_CreateInstance(id));
    if (!docLoaderFactory) {
        // try again after loading plugins
        nsresult err;
        NS_WITH_SERVICE(nsIPluginHost, pluginHost, kPluginManagerCID, &err);

        if (NS_FAILED(err))
            return NS_ERROR_FAILURE;

        pluginHost->LoadPlugins();

        docLoaderFactory = do_CreateInstance(id);

        if (!docLoaderFactory)
            return NS_ERROR_FAILURE;
    }

    nsCOMPtr<nsIChannel> aOpenedChannel = do_QueryInterface(request);

    // Now create an instance of the content viewer
    NS_ENSURE_SUCCESS(docLoaderFactory->CreateInstance("view",
                                                       aOpenedChannel,
                                                       aLoadGroup, aContentType,
                                                       NS_STATIC_CAST
                                                       (nsIContentViewerContainer
                                                        *, this), nsnull,
                                                       aContentHandler,
                                                       aViewer),
                      NS_ERROR_FAILURE);

    (*aViewer)->SetContainer(NS_STATIC_CAST(nsIContentViewerContainer *, this));

    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::SetupNewViewer(nsIContentViewer * aNewViewer)
{
    //
    // Copy content viewer state from previous or parent content viewer.
    //
    // The following logic is mirrored in nsHTMLDocument::StartDocumentLoad!
    //
    // Do NOT to maintain a reference to the old content viewer outside
    // of this "copying" block, or it will not be destroyed until the end of
    // this routine and all <SCRIPT>s and event handlers fail! (bug 20315)
    //
    // In this block of code, if we get an error result, we return it
    // but if we get a null pointer, that's perfectly legal for parent
    // and parentContentViewer.
    //

    PRInt32 x = 0;
    PRInt32 y = 0;
    PRInt32 cx = 0;
    PRInt32 cy = 0;

    // This will get the size from the current content viewer or from the
    // Init settings
    GetPositionAndSize(&x, &y, &cx, &cy);

    nsCOMPtr<nsIDocShellTreeItem> parentAsItem;
    NS_ENSURE_SUCCESS(GetSameTypeParent(getter_AddRefs(parentAsItem)),
                      NS_ERROR_FAILURE);
    nsCOMPtr<nsIDocShell> parent(do_QueryInterface(parentAsItem));
#ifdef IBMBIDI
    PRUint32 options;
    nsIMarkupDocumentViewer *newViewer = nsnull;
#endif // IBMBIDI

    if (mContentViewer || parent) {
        nsCOMPtr<nsIMarkupDocumentViewer> oldMUDV;
        if (mContentViewer) {
            // Get any interesting state from old content viewer
            // XXX: it would be far better to just reuse the document viewer ,
            //      since we know we're just displaying the same document as before
            oldMUDV = do_QueryInterface(mContentViewer);
        }
        else {
            // No old content viewer, so get state from parent's content viewer
            nsCOMPtr<nsIContentViewer> parentContentViewer;
            parent->GetContentViewer(getter_AddRefs(parentContentViewer));
            oldMUDV = do_QueryInterface(parentContentViewer);
        }

        nsXPIDLString defaultCharset;
        nsXPIDLString forceCharset;
        nsXPIDLString hintCharset;
        PRInt32 hintCharsetSource;

        nsCOMPtr<nsIMarkupDocumentViewer>
            newMUDV(do_QueryInterface(aNewViewer));
        if (oldMUDV && newMUDV) {
            NS_ENSURE_SUCCESS(oldMUDV->
                              GetDefaultCharacterSet(getter_Copies
                                                     (defaultCharset)),
                              NS_ERROR_FAILURE);
            NS_ENSURE_SUCCESS(oldMUDV->
                              GetForceCharacterSet(getter_Copies(forceCharset)),
                              NS_ERROR_FAILURE);
            NS_ENSURE_SUCCESS(oldMUDV->
                              GetHintCharacterSet(getter_Copies(hintCharset)),
                              NS_ERROR_FAILURE);
            NS_ENSURE_SUCCESS(oldMUDV->
                              GetHintCharacterSetSource(&hintCharsetSource),
                              NS_ERROR_FAILURE);
#ifdef IBMBIDI
            NS_ENSURE_SUCCESS(oldMUDV->GetBidiOptions(&options),
                              NS_ERROR_FAILURE);
            newViewer = newMUDV.get();
#endif // IBMBIDI

            // set the old state onto the new content viewer
            NS_ENSURE_SUCCESS(newMUDV->SetDefaultCharacterSet(defaultCharset),
                              NS_ERROR_FAILURE);
            NS_ENSURE_SUCCESS(newMUDV->SetForceCharacterSet(forceCharset),
                              NS_ERROR_FAILURE);
            NS_ENSURE_SUCCESS(newMUDV->SetHintCharacterSet(hintCharset),
                              NS_ERROR_FAILURE);
            NS_ENSURE_SUCCESS(newMUDV->
                              SetHintCharacterSetSource(hintCharsetSource),
                              NS_ERROR_FAILURE);
        }
    }

    // It is necessary to obtain the focus controller to utilize its ability
    // to suppress focus.  This is necessary to fix Win32-only bugs related to
    // a loss of focus when mContentViewer is set to null.  The internal window
    // is destroyed, and the OS focuses the parent window.  This call ends up
    // notifying the focus controller that the outer window should focus
    // and this hoses us on any link traversal.
    //
    // Please do not touch any of the focus controller code here without
    // testing bugs #28580 and 50509.  These are immensely important bugs,
    // so PLEASE take care not to regress them if you decide to alter this 
    // code later              -- hyatt
    nsCOMPtr<nsIFocusController> focusController;
    if (mScriptGlobal) {
        nsCOMPtr<nsPIDOMWindow> ourWindow = do_QueryInterface(mScriptGlobal);
        ourWindow->GetRootFocusController(getter_AddRefs(focusController));
        if (focusController) {
            // Suppress the command dispatcher.
            focusController->SetSuppressFocus(PR_TRUE,
                                              "Win32-Only Link Traversal Issue");
        }
    }

    nscolor bgcolor = NS_RGBA(0, 0, 0, 0);
    PRBool bgSet = PR_FALSE;

    // Ensure that the content viewer is destroyed *after* the GC - bug 71515
    nsCOMPtr<nsIContentViewer> kungfuDeathGrip = mContentViewer;
    if (mContentViewer) {
        // Stop any activity that may be happening in the old document before
        // releasing it...
        mContentViewer->Stop();

        // Try to extract the default background color from the old
        // view manager, so we can use it for the next document.
        nsCOMPtr<nsIDocumentViewer> docviewer =
            do_QueryInterface(mContentViewer);

        if (docviewer) {
            nsCOMPtr<nsIPresShell> shell;
            docviewer->GetPresShell(*getter_AddRefs(shell));

            if (shell) {
                nsCOMPtr<nsIViewManager> vm;
                shell->GetViewManager(getter_AddRefs(vm));

                if (vm) {
                    vm->GetDefaultBackgroundColor(&bgcolor);
                    bgSet = PR_TRUE;
                }
            }
        }

        mContentViewer->Destroy();
        mContentViewer = nsnull;
    }

    // End copying block (Don't mess with the old content/document viewer
    // beyond here!!)

    // See the book I wrote above regarding why the focus controller is 
    // being used here.  -- hyatt
    if (focusController)
        focusController->SetSuppressFocus(PR_FALSE,
                                          "Win32-Only Link Traversal Issue");

    mContentViewer = aNewViewer;

    nsCOMPtr<nsIWidget> widget;
    NS_ENSURE_SUCCESS(GetMainWidget(getter_AddRefs(widget)), NS_ERROR_FAILURE);
    if (!widget) {
        NS_ERROR("GetMainWidget coughed up a null widget");
        return NS_ERROR_FAILURE;
    }

    nsRect bounds(x, y, cx, cy);
    NS_ENSURE_SUCCESS(EnsureDeviceContext(), NS_ERROR_FAILURE);
    if (NS_FAILED(mContentViewer->Init(widget, mDeviceContext, bounds))) {
        mContentViewer = nsnull;
        NS_ERROR("ContentViewer Initialization failed");
        return NS_ERROR_FAILURE;
    }

    if (bgSet) {
        // Stuff the bgcolor from the last view manager into the new
        // view manager. This improves page load continuity.
        nsCOMPtr<nsIDocumentViewer> docviewer =
            do_QueryInterface(mContentViewer);

        if (docviewer) {
            nsCOMPtr<nsIPresShell> shell;
            docviewer->GetPresShell(*getter_AddRefs(shell));

            if (shell) {
                nsCOMPtr<nsIViewManager> vm;
                shell->GetViewManager(getter_AddRefs(vm));

                if (vm) {
                    vm->SetDefaultBackgroundColor(bgcolor);
                }
            }
        }
    }

#ifdef IBMBIDI
    if (newViewer) {
        // set the old state onto the new content viewer
        NS_ENSURE_SUCCESS(newViewer->SetBidiOptions(options), NS_ERROR_FAILURE);
    }
#endif // IBMBIDI
// XXX: It looks like the LayoutState gets restored again in Embed()
//      right after the call to SetupNewViewer(...)

    mContentViewer->Show();

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

    return NS_OK;
}

//*****************************************************************************
// nsDocShell: Site Loading
//*****************************************************************************   
NS_IMETHODIMP
nsDocShell::InternalLoad(nsIURI * aURI, nsIURI * aReferrer,
                         nsISupports * aOwner, PRBool aInheritOwner,
                         PRBool aStopActiveDoc, const char *aWindowTarget,
                         nsIInputStream * aPostData,
                         nsIInputStream * aHeadersData, PRUint32 aLoadType,
                         nsISHEntry * aSHEntry)
{
    if (mDisallowPopupWindows && aWindowTarget && aWindowTarget[0] != '\0') {
        PRBool isChrome = PR_FALSE;
        PRBool isResource = PR_FALSE;
        if (NS_SUCCEEDED(aURI->SchemeIs("chrome", &isChrome)) &&
            NS_SUCCEEDED(aURI->SchemeIs("resource", &isResource)) &&
            !isChrome && !isResource) {
            static const char top[] = "_top";
            if (!nsCRT::strcmp(aWindowTarget, "_blank") ||
                !nsCRT::strcmp(aWindowTarget, "_new")) {
                aWindowTarget = top;
            }
            else {
                nsCOMPtr<nsIDocShellTreeItem> targetDocShell;
                FindItemWithName(NS_ConvertASCIItoUCS2(aWindowTarget).
                                 GetUnicode(),
                                 NS_STATIC_CAST(nsIInterfaceRequestor *, this),
                                 getter_AddRefs(targetDocShell));
                if (!targetDocShell)
                    aWindowTarget = top;
            }
        }
    }

    mURIResultedInDocument = PR_FALSE;  // reset the clock...
    // Check to see if the new URI is an anchor in the existing document.
    if ((aLoadType == LOAD_NORMAL ||
         aLoadType == LOAD_NORMAL_REPLACE ||
         aLoadType == LOAD_HISTORY ||
         aLoadType == LOAD_LINK) && (aPostData == nsnull)) {
        PRBool wasAnchor = PR_FALSE;
        NS_ENSURE_SUCCESS(ScrollIfAnchor(aURI, &wasAnchor), NS_ERROR_FAILURE);
        if (wasAnchor) {
            mLoadType = aLoadType;
            mURIResultedInDocument = PR_TRUE;
            OnNewURI(aURI, nsnull, mLoadType);

            /* Clear out LSHE so that further anchor visits get
               * recorded in SH and SH won't misbehave. i think this is  
               * sufficient for now to take care of any Sh mis-behaviors.
               * Other option is to call OnEndDocumentLoad() with a dummy channel
               * and uriloader and letting everybody know that we are done
               *  with this target load. I don't think that is necessay
               * considering that nsIDocLoaderObserver is on its way out.
               *  Hopefully  the following is sufficient.
             */
            LSHE = nsnull;
            /* Set the title for the SH entry for this target url. so that
             * SH menus in go/back/forward buttons won't be empty for this.
             */
            if (mSessionHistory) {
                PRInt32 index = -1;
                mSessionHistory->GetIndex(&index);
                nsCOMPtr<nsIHistoryEntry> hEntry;
                mSessionHistory->GetEntryAtIndex(index, PR_FALSE,
                                                 getter_AddRefs(hEntry));
                NS_ENSURE_TRUE(hEntry, NS_ERROR_FAILURE);
                nsCOMPtr<nsISHEntry> shEntry(do_QueryInterface(hEntry));
                if (shEntry)
                    shEntry->SetTitle(mTitle.GetUnicode());
            }

            return NS_OK;
        }
    }

    NS_ENSURE_SUCCESS(StopLoad(), NS_ERROR_FAILURE);
    // Cancel any timers that were set for this loader.
    CancelRefreshURITimers();

    if (aStopActiveDoc && mContentViewer) {
        mContentViewer->Stop();
    }

    mLoadType = aLoadType;
    LSHE = aSHEntry;

    nsDocShellInfoLoadType loadCmd =
        ConvertLoadTypeToDocShellLoadInfo(mLoadType);
    NS_ENSURE_SUCCESS(DoURILoad
                      (aURI, aReferrer, aOwner, aInheritOwner, loadCmd,
                       aWindowTarget, aPostData, aHeadersData),
                      NS_ERROR_FAILURE);

    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::CreateFixupURI(const PRUnichar * aStringURI, nsIURI ** aURI)
{
    *aURI = nsnull;
    nsAutoString uriString(aStringURI);
    uriString.Trim(" ");        // Cleanup the empty spaces that might be on each end.

    // Eliminate embedded newlines, which single-line text fields now allow:
    uriString.StripChars("\r\n");

    // Create the fixup object if necessary
    if (!mURIFixup) {
        mURIFixup = do_GetService(NS_URIFIXUP_CONTRACTID);
        if (!mURIFixup) {
            // No fixup service so try and create a URI and see what happens
            return NS_NewURI(aURI, uriString, nsnull);
        }
    }

    // Call the fixup object
    return mURIFixup->CreateFixupURI(aStringURI, aURI);
}

NS_IMETHODIMP
nsDocShell::GetCurrentDocumentOwner(nsISupports ** aOwner)
{
    nsresult rv;
    *aOwner = nsnull;
    nsCOMPtr<nsIDocument> document;
    //-- Get the current document
    if (mContentViewer) {
        nsCOMPtr<nsIDocumentViewer>
            docViewer(do_QueryInterface(mContentViewer));
        if (!docViewer)
            return NS_ERROR_FAILURE;
        rv = docViewer->GetDocument(*getter_AddRefs(document));
    }
    else                        //-- If there's no document loaded yet, look at the parent (frameset)
    {
        nsCOMPtr<nsIDocShellTreeItem> parentItem;
        rv = GetSameTypeParent(getter_AddRefs(parentItem));
        if (NS_FAILED(rv) || !parentItem)
            return rv;
        nsCOMPtr<nsIDOMWindowInternal>
            parentWindow(do_GetInterface(parentItem));
        if (!parentWindow)
            return NS_OK;
        nsCOMPtr<nsIDOMDocument> parentDomDoc;
        rv = parentWindow->GetDocument(getter_AddRefs(parentDomDoc));
        if (!parentDomDoc)
            return NS_OK;
        document = do_QueryInterface(parentDomDoc);
    }

    //-- Get the document's principal
    nsCOMPtr<nsIPrincipal> principal;
    rv = document->GetPrincipal(getter_AddRefs(principal));
    if (NS_FAILED(rv) || !principal)
        return NS_ERROR_FAILURE;
    rv = principal->QueryInterface(NS_GET_IID(nsISupports), (void **) aOwner);
    return rv;
}

NS_IMETHODIMP
nsDocShell::DoURILoad(nsIURI * aURI, nsIURI * aReferrerURI,
                      nsISupports * aOwner, PRBool aInheritOwner,
                      nsURILoadCommand aLoadCmd, const char *aWindowTarget,
                      nsIInputStream * aPostData, nsIInputStream * aHeadersData)
{
    static const char jsSchemeName[] = "javascript";
    // if the load cmd is a user click....and we are supposed to try using
    // external default protocol handlers....then try to see if we have one for
    // this protocol
    if (mUseExternalProtocolHandler && aLoadCmd == nsIURILoader::viewUserClick) {
        nsXPIDLCString urlScheme;
        aURI->GetScheme(getter_Copies(urlScheme));
        // don't do it for javascript urls!
        if (urlScheme && nsCRT::strcasecmp(jsSchemeName, urlScheme)
            && (!nsCRT::strcasecmp(aWindowTarget, "_content") ||
                !nsCRT::strcasecmp(aWindowTarget, "_blank"))) {
            nsCOMPtr<nsIExternalProtocolService>
                extProtService(do_GetService
                               (NS_EXTERNALPROTOCOLSERVICE_CONTRACTID));
            PRBool haveHandler = PR_FALSE;
            extProtService->ExternalProtocolHandlerExists(urlScheme,
                                                          &haveHandler);
            if (haveHandler)
                return extProtService->LoadUrl(aURI);
        }
    }
    nsCOMPtr<nsIURILoader>
        uriLoader(do_GetService(NS_URI_LOADER_CONTRACTID));
    NS_ENSURE_TRUE(uriLoader, NS_ERROR_FAILURE);

    // we need to get the load group from our load cookie so we can pass it into open uri...
    nsCOMPtr<nsILoadGroup> loadGroup;
    NS_ENSURE_SUCCESS(uriLoader->
                      GetLoadGroupForContext(NS_STATIC_CAST
                                             (nsIDocShell *, this),
                                             getter_AddRefs(loadGroup)),
                      NS_ERROR_FAILURE);

    // open a channel for the url
    nsCOMPtr<nsIChannel> channel;
    nsresult rv;

    nsCOMPtr<nsIInterfaceRequestor> ifreq;

    // This is a workaround to get javascript: URL's with a target
    // attribute execute in the correct window, this only works if the
    // target window exists when the link is clicked.
    if (aWindowTarget && *aWindowTarget) {
        PRBool isJSURL = PR_FALSE;
        // do it only for javascript urls!
        if (NS_SUCCEEDED(aURI->SchemeIs("javascript", &isJSURL)) && isJSURL) {
            nsAutoString targetName;
            targetName.AssignWithConversion(aWindowTarget);

            nsCOMPtr<nsIDocShellTreeItem> targetDocShell;

            FindItemWithName(targetName.GetUnicode(),
                             NS_STATIC_CAST(nsIInterfaceRequestor *, this),
                             getter_AddRefs(targetDocShell));

            ifreq = do_QueryInterface(targetDocShell);
        }
    }
    // End of workaround.

    if (!ifreq)
        ifreq = NS_STATIC_CAST(nsIInterfaceRequestor *, this);

    rv = NS_OpenURI(getter_AddRefs(channel), aURI, nsnull, loadGroup, ifreq);
    if (NS_FAILED(rv)) {
        if (NS_ERROR_DOM_RETVAL_UNDEFINED == rv)        // if causing the channel changed the
            return NS_OK;       // dom and there is nothing else to do
        else
            return NS_ERROR_FAILURE;
    }
    channel->SetOriginalURI(aURI);

    nsCOMPtr<nsIHTTPChannel> httpChannel(do_QueryInterface(channel));
    if (httpChannel) {
        nsCOMPtr<nsICachingChannel>
            cacheChannel(do_QueryInterface(httpChannel));
        /* Get the cache Key from SH */
        nsCOMPtr<nsISupports> cacheKey;
        if (LSHE) {
            LSHE->GetCacheKey(getter_AddRefs(cacheKey));
        }
        else if (OSHE)          // for reload cases
            OSHE->GetCacheKey(getter_AddRefs(cacheKey));

        // figure out if we need to set the post data stream on the channel...
        // right now, this is only done for http channels.....
        if (aPostData) {
            // XXX it's a bit of a hack to rewind the postdata stream here but
            // it has to be done in case the post data is being reused multiple
            // times.
            nsCOMPtr<nsIRandomAccessStore>
                postDataRandomAccess(do_QueryInterface(aPostData));
            if (postDataRandomAccess) {
                postDataRandomAccess->Seek(PR_SEEK_SET, 0);
            }

            nsCOMPtr<nsIAtom> method = NS_NewAtom("POST");
            httpChannel->SetRequestMethod(method);
            httpChannel->SetUploadStream(aPostData);
            /* If there is a valid postdata *and* it is a History Load,
             * set up the cache key on the channel, to retrieve the
             * data only from the cache. When there is a postdata
             * on a history load, we do not want to go out to the net
             * in our first attempt. We will go out to the net for a
             * post data result, *only* if it has expired from cache *and*
             * the user has given us permission to do so.
             */
            if (mLoadType == LOAD_HISTORY || mLoadType == LOAD_RELOAD_NORMAL) {
                if (cacheChannel && cacheKey)
                    cacheChannel->SetCacheKey(cacheKey, PR_TRUE);
            }
        }
        else {
            /* If there is no postdata, set the cache key on the channel
             * with the readFromCacheOnly set to false, so that cache will
             * be free to get it from net if it is not found in cache.
             * New cache may use it creatively on CGI pages with GET
             * method and even on those that say "no-cache"
             */
            if (mLoadType == LOAD_HISTORY || mLoadType == LOAD_RELOAD_NORMAL) {
                if (cacheChannel && cacheKey)
                    cacheChannel->SetCacheKey(cacheKey, PR_FALSE);
            }
        }
        if (aHeadersData) {
            rv = AddHeadersToChannel(aHeadersData, httpChannel);
        }
        // Set the referrer explicitly
        if (aReferrerURI)       // Referrer is currenly only set for link clicks here.
            httpChannel->SetReferrer(aReferrerURI,
                                     nsIHTTPChannel::REFERRER_LINK_CLICK);
    }
    else {
        // iff we are dealing with a JS or a data url, we may need an inherited owner.
        // This is either aOwner or the owner of the current document.
        nsCOMPtr<nsISupports> owner = aOwner;
        PRBool isJSOrData = PR_FALSE;
        nsCOMPtr<nsIStreamIOChannel> ioChannel(do_QueryInterface(channel));
        if (ioChannel)          // Might be a javascript: URL load, need to set owner
        {
            aURI->SchemeIs("javascript", &isJSOrData);
        }
        else {                  // Also set owner for data: URLs
            nsCOMPtr<nsIDataChannel> dataChannel(do_QueryInterface(channel));
            isJSOrData = (dataChannel != nsnull);
        }

        if (isJSOrData) {
            if (!owner)         // If an owner was passed in, use it
            {
                // Otherwise, if the caller has allowed inheriting from the current document,
                // or if we're being called from chrome (which has the system principal),
                // then use the current document principal
                if (!aInheritOwner) {
                    // See if there's system or chrome JS code running
                    NS_WITH_SERVICE(nsIScriptSecurityManager, secMan,
                                    kSecurityManagerCID, &rv);
                    nsCOMPtr<nsIPrincipal> sysPrin;
                    if (NS_SUCCEEDED(rv))
                        rv = secMan->GetSystemPrincipal(getter_AddRefs(sysPrin));       // Just to compare, not to use!
                    nsCOMPtr<nsIPrincipal> subjectPrin;
                    if (NS_SUCCEEDED(rv))
                        rv = secMan->
                            GetSubjectPrincipal(getter_AddRefs(subjectPrin));
                    if (NS_SUCCEEDED(rv)
                        && (!subjectPrin || sysPrin.get() == subjectPrin.get()))
                        aInheritOwner = PR_TRUE;
                }
                if (aInheritOwner)
                    GetCurrentDocumentOwner(getter_AddRefs(owner));
            }
            channel->SetOwner(owner);
        }
    }

    NS_ENSURE_SUCCESS(DoChannelLoad
                      (channel, aLoadCmd, aWindowTarget, uriLoader),
                      NS_ERROR_FAILURE);

    return NS_OK;
}

static NS_METHOD
AHTC_WriteFunc(nsIInputStream * in,
               void *closure,
               const char *fromRawSegment,
               PRUint32 toOffset, PRUint32 count, PRUint32 * writeCount)
{
    if (nsnull == writeCount || nsnull == closure ||
        nsnull == fromRawSegment || nsCRT::strlen(fromRawSegment) < 1) {
        return NS_BASE_STREAM_CLOSED;
    }

    *writeCount = 0;
    char *headersBuf = *((char **) closure);
    // pointer to where we should start copying bytes from rawSegment
    char *pHeadersBuf = nsnull;
    PRUint32 headersBufLen;
    PRUint32 rawSegmentLen = nsCRT::strlen(fromRawSegment);

    // if the buffer has no data yet
    if (!headersBuf) {
        headersBufLen = rawSegmentLen;
        pHeadersBuf = headersBuf = (char *) nsMemory::Alloc(headersBufLen + 1);
        if (!headersBuf) {
            return NS_BASE_STREAM_WOULD_BLOCK;
        }
        nsCRT::memset(headersBuf, nsnull, headersBufLen + 1);
    }
    else {
        // data has been read, reallocate
        // store a pointer to the old full buffer
        pHeadersBuf = headersBuf;

        // create a new buffer
        headersBufLen = nsCRT::strlen(headersBuf);
        headersBuf =
            (char *) nsMemory::Alloc(rawSegmentLen + headersBufLen + 1);
        if (!headersBuf) {
            headersBuf = pHeadersBuf;
            pHeadersBuf = nsnull;
            return NS_BASE_STREAM_WOULD_BLOCK;
        }
        memset(headersBuf, nsnull, rawSegmentLen + headersBufLen + 1);
        // copy the old buffer to the beginning of the new buffer
        nsCRT::memcpy(headersBuf, pHeadersBuf, headersBufLen);
        // free the old buffer
        nsCRT::free(pHeadersBuf);
        // make the buffer pointer point to the writeable part
        // of the new buffer
        pHeadersBuf = headersBuf + headersBufLen;
        // increment the length of the buffer
        headersBufLen += rawSegmentLen;
    }

    // at this point, pHeadersBuf points to where we should copy bits
    // from fromRawSegment.
    nsCRT::memcpy(pHeadersBuf, fromRawSegment, rawSegmentLen);
    // null termination
    headersBuf[headersBufLen] = nsnull;
    *((char **) closure) = headersBuf;
    *writeCount = rawSegmentLen;

    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::AddHeadersToChannel(nsIInputStream * aHeadersData,
                                nsIChannel * aGenericChannel)
{
    if (nsnull == aHeadersData || nsnull == aGenericChannel) {
        return NS_ERROR_NULL_POINTER;
    }
    nsCOMPtr<nsIHTTPChannel> aChannel = do_QueryInterface(aGenericChannel);
    if (!aChannel) {
        return NS_ERROR_NULL_POINTER;
    }

    // used during the manipulation of the InputStream
    nsresult rv = NS_ERROR_FAILURE;
    PRUint32 available = 0;
    PRUint32 bytesRead;
    char *headersBuf = nsnull;

    // used during the manipulation of the String from the InputStream
    nsCAutoString headersString;
    nsCAutoString oneHeader;
    nsCAutoString headerName;
    nsCAutoString headerValue;
    PRInt32 crlf = 0;
    PRInt32 colon = 0;
    nsCOMPtr<nsIAtom> headerAtom;

    //
    // Suck all the data out of the nsIInputStream into a char * buffer.
    //

    rv = aHeadersData->Available(&available);
    if (NS_FAILED(rv) || available < 1) {
        goto AHTC_CLEANUP;
    }

    do {
        aHeadersData->ReadSegments(AHTC_WriteFunc, &headersBuf, available,
                                   &bytesRead);
        rv = aHeadersData->Available(&available);
        if (NS_FAILED(rv)) {
            goto AHTC_CLEANUP;
        }
    } while (0 < available);

    //
    // Turn the char * buffer into an nsString.
    //
    headersString = (const char *) headersBuf;

    //
    // Iterate over the nsString: for each "\r\n" delimeted chunk,
    // add the value as a header to the nsIHTTPChannel
    //

    while (PR_TRUE) {
        crlf = headersString.Find("\r\n", PR_TRUE);
        if (-1 == crlf) {
            rv = NS_OK;
            goto AHTC_CLEANUP;
        }
        headersString.Mid(oneHeader, 0, crlf);
        headersString.Cut(0, crlf + 2);
        oneHeader.StripWhitespace();
        colon = oneHeader.Find(":");
        if (-1 == colon) {
            rv = NS_ERROR_NULL_POINTER;
            goto AHTC_CLEANUP;
        }
        oneHeader.Left(headerName, colon);
        colon++;
        oneHeader.Mid(headerValue, colon, oneHeader.Length() - colon);
        headerAtom = dont_AddRef(NS_NewAtom(headerName.get()));
        if (!headerAtom) {
            rv = NS_ERROR_NULL_POINTER;
            goto AHTC_CLEANUP;
        }

        //
        // FINALLY: we can set the header!
        // 

        rv = aChannel->SetRequestHeader(headerAtom, headerValue.get());
        if (NS_FAILED(rv)) {
            rv = NS_ERROR_NULL_POINTER;
            goto AHTC_CLEANUP;
        }
    }

  AHTC_CLEANUP:
    nsMemory::Free((void *) headersBuf);
    headersBuf = nsnull;
    return rv;
}

NS_IMETHODIMP
nsDocShell::DoChannelLoad(nsIChannel * aChannel, nsURILoadCommand aLoadCmd,
                          const char *aWindowTarget, nsIURILoader * aURILoader)
{
    // Mark the channel as being a document URI...
    nsLoadFlags loadFlags = 0;
    (void) aChannel->GetLoadFlags(&loadFlags);
    loadFlags |= nsIChannel::LOAD_DOCUMENT_URI;

    // Load attributes depend on load type...
    switch (mLoadType) {
    case LOAD_HISTORY:
        loadFlags |= nsIRequest::LOAD_FROM_CACHE;
        break;

    case LOAD_RELOAD_NORMAL:
        loadFlags |= nsIRequest::VALIDATE_ALWAYS;
        break;

    case LOAD_RELOAD_BYPASS_PROXY_AND_CACHE:
    case LOAD_REFRESH:
        loadFlags |= nsIRequest::LOAD_BYPASS_CACHE;
        break;
    case LOAD_NORMAL:
    case LOAD_LINK:
        // Set cache checking flags
        if (mPrefs) {
            PRInt32 prefSetting;
            if (NS_SUCCEEDED
                (mPrefs->
                 GetIntPref("browser.cache.check_doc_frequency",
                            &prefSetting))) {
                switch (prefSetting) {
                case 0:
                    loadFlags |= nsIRequest::VALIDATE_ONCE_PER_SESSION;
                    break;
                case 1:
                    loadFlags |= nsIRequest::VALIDATE_ALWAYS;
                    break;
                case 2:
                    loadFlags |= nsIRequest::VALIDATE_NEVER;
                    break;
                }
            }
        }
        break;
    }

    (void) aChannel->SetLoadFlags(loadFlags);

    NS_ENSURE_SUCCESS(aURILoader->OpenURI(aChannel, aLoadCmd,
                                          aWindowTarget,
                                          NS_STATIC_CAST(nsIDocShell *, this)),
                      NS_ERROR_FAILURE);

    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::ScrollIfAnchor(nsIURI * aURI, PRBool * aWasAnchor)
{
    NS_ASSERTION(aURI, "null uri arg");
    NS_ASSERTION(aWasAnchor, "null anchor arg");

    if (aURI == nsnull || aWasAnchor == nsnull) {
        return NS_ERROR_FAILURE;
    }

    *aWasAnchor = PR_FALSE;

    if (!mCurrentURI) {
        return NS_OK;
    }

    nsresult rv;

    // NOTE: we assume URIs are absolute for comparison purposes

    nsXPIDLCString currentSpec;
    NS_ENSURE_SUCCESS(mCurrentURI->GetSpec(getter_Copies(currentSpec)),
                      NS_ERROR_FAILURE);

    nsXPIDLCString newSpec;
    NS_ENSURE_SUCCESS(aURI->GetSpec(getter_Copies(newSpec)), NS_ERROR_FAILURE);

    // Search for hash marks in the current URI and the new URI and
    // take a copy of everything to the left of the hash for
    // comparison.

    const char kHash = '#';

    // Split the new URI into a left and right part
    nsAutoString sNew;
    sNew.AssignWithConversion(newSpec);
    nsAutoString sNewLeft;
    nsAutoString sNewRef;
    PRInt32 hashNew = sNew.FindChar(kHash);
    if (hashNew == 0) {
        return NS_OK;           // Strange URI 
    }
    else if (hashNew > 0) {
        sNew.Left(sNewLeft, hashNew);
        sNew.Right(sNewRef, sNew.Length() - hashNew - 1);
    }
    else {
        sNewLeft = sNew;
    }

    // Split the current URI in a left and right part
    nsAutoString sCurrent;
    sCurrent.AssignWithConversion(currentSpec);
    nsAutoString sCurrentLeft;
    PRInt32 hashCurrent = sCurrent.FindChar(kHash);
    if (hashCurrent == 0) {
        return NS_OK;           // Strange URI 
    }
    else if (hashCurrent > 0) {
        sCurrent.Left(sCurrentLeft, hashCurrent);
    }
    else {
        sCurrentLeft = sCurrent;
    }

    // Exit when there are no anchors
    if (hashNew <= 0 && hashCurrent <= 0) {
        return NS_OK;
    }

    // Compare the URIs.
    //
    // NOTE: this is a case sensitive comparison because some parts of the
    // URI are case sensitive, and some are not. i.e. the domain name
    // is case insensitive but the the paths are not.
    //
    // This means that comparing "http://www.ABC.com/" to "http://www.abc.com/"
    // will fail this test.

    if (sCurrentLeft.CompareWithConversion(sNewLeft, PR_FALSE, -1) != 0) {
        return NS_OK;           // URIs not the same
    }

    // Both the new and current URIs refer to the same page. We can now
    // browse to the hash stored in the new URI.

    if (!sNewRef.IsEmpty()) {
        nsCOMPtr<nsIPresShell> shell = nsnull;
        rv = GetPresShell(getter_AddRefs(shell));
        if (NS_SUCCEEDED(rv) && shell) {
            *aWasAnchor = PR_TRUE;

            char *str = sNewRef.ToNewCString();

            // nsUnescape modifies the string that is passed into it.
            nsUnescape(str);

            // We assume that the bytes are in UTF-8, as it says in the spec:
            // http://www.w3.org/TR/html4/appendix/notes.html#h-B.2.1
            nsAutoString savedNewRef(sNewRef);
            sNewRef = NS_ConvertUTF8toUCS2(str);

            nsMemory::Free(str);

            // We try the UTF-8 string first, and then try the document's charset (see below).
            rv = shell->GoToAnchor(sNewRef);

            // Above will fail if the anchor name is not UTF-8.
            // Need to convert from document charset to unicode.
            if (NS_FAILED(rv)) {
                // Get a document charset
                NS_ENSURE_TRUE(mContentViewer, NS_ERROR_FAILURE);
                nsCOMPtr<nsIDocumentViewer>
                    docv(do_QueryInterface(mContentViewer));
                NS_ENSURE_TRUE(docv, NS_ERROR_FAILURE);
                nsCOMPtr<nsIDocument> doc;
                rv = docv->GetDocument(*getter_AddRefs(doc));
                NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
                nsAutoString aCharset;
                rv = doc->GetDocumentCharacterSet(aCharset);
                NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
                char *charsetStr = aCharset.ToNewCString();
                NS_ENSURE_TRUE(charsetStr, NS_ERROR_OUT_OF_MEMORY);

                // Use the saved string
                char *uriStr = savedNewRef.ToNewCString();
                if (!uriStr) {
                    nsMemory::Free(charsetStr);
                    return NS_ERROR_OUT_OF_MEMORY;
                }

                nsCOMPtr<nsITextToSubURI> textToSubURI =
                    do_GetService(NS_ITEXTTOSUBURI_CONTRACTID, &rv);
                if (NS_FAILED(rv)) {
                    nsMemory::Free(uriStr);
                    nsMemory::Free(charsetStr);
                    return NS_ERROR_FAILURE;
                }

                // Unescape and convert to unicode
                PRUnichar *uStr;
                rv = textToSubURI->UnEscapeAndConvert(charsetStr, uriStr,
                                                      &uStr);
                nsMemory::Free(uriStr);
                nsMemory::Free(charsetStr);
                NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);

                sNewRef.Assign(uStr);
                nsMemory::Free(uStr);

                rv = shell->GoToAnchor(sNewRef);
            }
        }
    }
    else {
        // A bit of a hack - scroll to the top of the page.
        SetCurScrollPosEx(0, 0);
        *aWasAnchor = PR_TRUE;
    }

    return NS_OK;
}


NS_IMETHODIMP
nsDocShell::OnNewURI(nsIURI * aURI, nsIChannel * aChannel,
                     PRUint32 aLoadType)
{
    NS_ASSERTION(aURI, "uri is null");

    UpdateCurrentGlobalHistory();
    PRBool updateHistory = PR_TRUE;
    PRBool equalUri = PR_FALSE;

    // Get the post data from the channel
    nsCOMPtr<nsIInputStream> inputStream;
    if (aChannel) {
        nsCOMPtr<nsIHTTPChannel> httpChannel(do_QueryInterface(aChannel));

        if (httpChannel) {
            httpChannel->GetUploadStream(getter_AddRefs(inputStream));
        }
    }
    // Determine if this type of load should update history
    if (aLoadType & LOAD_FLAGS_BYPASS_HISTORY ||
        aLoadType & LOAD_CMD_RELOAD || aLoadType & LOAD_CMD_HISTORY ||
        (mCurrentURI && NS_SUCCEEDED(mCurrentURI->Equals(aURI, &equalUri))
         && equalUri && !inputStream)) {
        updateHistory = PR_FALSE;
    }

    if (updateHistory) {        // Page load not from SH
        // Update session history if necessary...
        if (!LSHE && (mItemType == typeContent) && mURIResultedInDocument) {
            /* This is  a fresh page getting loaded for the first time
             *.Create a Entry for it and add it to SH, if this is the
             * rootDocShell
             */
            (void) AddToSessionHistory(aURI, aChannel, getter_AddRefs(LSHE));
        }

        // Update Global history if necessary...
        updateHistory = PR_FALSE;
        ShouldAddToGlobalHistory(aURI, &updateHistory);
        if (updateHistory) {
            AddToGlobalHistory(aURI);
        }
    }

    SetCurrentURI(aURI);
    // if there's a refresh header in the channel, this method
    // will set it up for us. 
    SetupRefreshURI(aChannel);

    mInitialPageLoad = PR_FALSE;
    return NS_OK;
}

nsresult
nsDocShell::RefreshURIFromHeader(nsIURI * aBaseURI,
                                 const nsAReadableString & aHeader)
{
    // Refresh headers are parsed with the following format in mind
    // <META HTTP-EQUIV=REFRESH CONTENT="5; URL=http://uri">
    // By the time we are here, the following is true:
    // header = "REFRESH"
    // content = "5; URL=http://uri" // note the URL attribute is
    // optional, if it is absent, the currently loaded url is used.
    // Also note that the seconds and URL separator can be either
    // a ';' or a ','. The ',' separator should be illegal but CNN
    // is using it.
    // 
    // We need to handle the following strings, where
    //  - X is a set of digits
    //  - URI is either a relative or absolute URI
    //
    // Note that URI should start with "url=" but we allow omission
    //
    // "" || ";" || "," 
    //  empty string. use the currently loaded URI
    //  and refresh immediately.
    // "X" || "X;" || "X,"
    //  Refresh the currently loaded URI in X seconds.
    // "X; URI" || "X, URI"
    //  Refresh using URI as the destination in X seconds.
    // "URI" || "; URI" || ", URI"
    //  Refresh immediately using URI as the destination.
    // 
    // Currently, anything immediately following the URI, if
    // seperated by any char in the set "'\"\t\r\n " will be
    // ignored. So "10; url=go.html ; foo=bar" will work,
    // and so will "10; url='go.html'; foo=bar". However,
    // "10; url=go.html; foo=bar" will result in the uri
    // "go.html;" since ';' and ',' are valid uri characters.
    // 
    // Note that we need to remove any tokens wrapping the URI.
    // These tokens currently include spaces, double and single
    // quotes.

    // when done, seconds is 0 or the given number of seconds
    //            uriAttrib is empty or the URI specified
    nsAutoString uriAttrib;
    PRInt32 seconds = 0;

    nsReadingIterator < PRUnichar > iter, tokenStart, doneIterating;

    aHeader.BeginReading(iter);
    aHeader.EndReading(doneIterating);

    // skip leading whitespace
    while (iter != doneIterating && nsCRT::IsAsciiSpace(*iter))
        ++iter;

    tokenStart = iter;

    // skip leading + and -
    if (iter != doneIterating && (*iter == '-' || *iter == '+'))
        ++iter;

    // parse number
    while (iter != doneIterating && (*iter >= '0' && *iter <= '9')) {
        seconds = seconds * 10 + (*iter - '0');
        ++iter;
    }

    // bug 22886, part 2: allow X to start with or contain a '.'
    if (iter != doneIterating && *iter == '.') {
        ++iter;
        // throw away any digits following it
        while (iter != doneIterating && (*iter >= '0' && *iter <= '9'))
            ++iter;
    }

    if (iter != doneIterating) {
        // if this isn't whitespace, a ';' or a ',', we just parsed part of a URI
        if (!(nsCRT::IsAsciiSpace(*iter) || *iter == ';' || *iter == ',')) {
            // back to square 1
            iter = tokenStart;
            seconds = 0;
        }
        else {
            // if we started with a '-', number is negative
            if (*tokenStart == '-')
                seconds = -seconds;

            // skip whitespace
            while (iter != doneIterating && nsCRT::IsAsciiSpace(*iter))
                ++iter;

            // skip ';' or ','
            if (iter != doneIterating && (*iter == ';' || *iter == ',')) {
                ++iter;

                // skip whitespace
                while (iter != doneIterating && nsCRT::IsAsciiSpace(*iter))
                    ++iter;
            }
        }
    }

    // possible start of URI
    tokenStart = iter;

    // skip "url = " to real start of URI
    if (iter != doneIterating && (*iter == 'u' || *iter == 'U')) {
        ++iter;
        if (iter != doneIterating && (*iter == 'r' || *iter == 'R')) {
            ++iter;
            if (iter != doneIterating && (*iter == 'l' || *iter == 'L')) {
                ++iter;

                // skip whitespace
                while (iter != doneIterating && nsCRT::IsAsciiSpace(*iter))
                    ++iter;

                if (iter != doneIterating && *iter == '=') {
                    ++iter;

                    // skip whitespace
                    while (iter != doneIterating && nsCRT::IsAsciiSpace(*iter))
                        ++iter;

                    // found real start of URI
                    tokenStart = iter;
                }
            }
        }
    }

    // skip a leading '"' (believe it or not, '\'' is a valid URI char)
    if (tokenStart != doneIterating && *tokenStart == '"')
        ++tokenStart;

    // set iter to start of URI
    iter = tokenStart;

    // tokenStart here points to the beginning of URI

    // skip anything which isn't whitespace or '"')
    while (iter != doneIterating
           && !(nsCRT::IsAsciiSpace(*iter) || *iter == '"'))
        ++iter;

    // URI is whatever's contained from tokenStart to iter.
    // note: if tokenStart == doneIterating, so is iter.

    nsresult rv = NS_OK;

    nsCOMPtr<nsIURI> uri;
    if (tokenStart == iter) {
        uri = aBaseURI;
    }
    else {
        uriAttrib = Substring(tokenStart, iter);
        rv = NS_NewURI(getter_AddRefs(uri), uriAttrib, aBaseURI);
    }

    if (NS_SUCCEEDED(rv)) {
        nsCOMPtr<nsIScriptSecurityManager>
            securityManager(do_GetService
                            (NS_SCRIPTSECURITYMANAGER_CONTRACTID, &rv));
        if (NS_SUCCEEDED(rv)) {
            rv = securityManager->CheckLoadURI(aBaseURI, uri,
                                               nsIScriptSecurityManager::
                                               DISALLOW_FROM_MAIL);
            if (NS_SUCCEEDED(rv)) {
                // since we can't travel back in time yet, just pretend it was meant figuratively
                if (seconds < 0)
                    seconds = 0;

                rv = RefreshURI(uri, seconds * 1000, PR_FALSE, PR_TRUE);
            }
        }
    }
    return rv;
}

NS_IMETHODIMP nsDocShell::SetupRefreshURI(nsIChannel * aChannel)
{
    nsresult
        rv;
    nsCOMPtr<nsIHTTPChannel> httpChannel(do_QueryInterface(aChannel, &rv));
    if (NS_SUCCEEDED(rv)) {
        nsCOMPtr<nsIURI> referrer;
        rv = httpChannel->GetReferrer(getter_AddRefs(referrer));

        if (NS_SUCCEEDED(rv)) {
            SetReferrerURI(referrer);

            nsCOMPtr<nsIAtom>
                refreshAtom(dont_AddRef(NS_NewAtom("refresh")));
            nsXPIDLCString
                refreshHeader;
            rv = httpChannel->GetResponseHeader(refreshAtom,
                                                getter_Copies(refreshHeader));

            if (refreshHeader)
                rv = RefreshURIFromHeader(mCurrentURI,
                                          NS_ConvertUTF8toUCS2(refreshHeader));
        }
    }
    return rv;
}

NS_IMETHODIMP
nsDocShell::OnLoadingSite(nsIChannel * aChannel)
{
    nsCOMPtr<nsIURI> uri;
    // If this a redirect, use the final url (uri)
    // else use the original url
    //
    // The better way would be to trust the OnRedirect() that necko gives us.
    // But this notification happen after the necko notification and hence
    // overrides it. Until OnRedirect() gets settles out, let us do this.
    nsLoadFlags loadFlags = 0;
    aChannel->GetLoadFlags(&loadFlags);
    if (loadFlags & nsIChannel::LOAD_REPLACE)
        aChannel->GetURI(getter_AddRefs(uri));
    else
        aChannel->GetOriginalURI(getter_AddRefs(uri));
    NS_ENSURE_TRUE(uri, NS_ERROR_FAILURE);

    OnNewURI(uri, aChannel, mLoadType);

    return NS_OK;
}

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

    nsCOMPtr<nsIDocumentLoader> loader(do_GetInterface(mLoadCookie));

    NS_ASSERTION(loader, "No document loader");
    if (loader) {
        loader->FireOnLocationChange(nsnull, nsnull, aURI);
    }
}

void
nsDocShell::SetReferrerURI(nsIURI * aURI)
{
    mReferrerURI = aURI;        // This assigment addrefs
}

//*****************************************************************************
// nsDocShell: Session History
//*****************************************************************************   
PRBool
nsDocShell::ShouldAddToSessionHistory(nsIURI * aURI)
{
    // I believe none of the about: urls should go in the history. But then
    // that could just be me... If the intent is only deny about:blank then we
    // should just do a spec compare, rather than two gets of the scheme and
    // then the path.  -Gagan
    nsresult rv;
    nsXPIDLCString buffer;
    nsCAutoString schemeStr;

    rv = aURI->GetScheme(getter_Copies(buffer));
    if (NS_FAILED(rv))
        return PR_FALSE;

    schemeStr = buffer;
    if (schemeStr.Equals("about")) {
        rv = aURI->GetPath(getter_Copies(buffer));
        if (NS_FAILED(rv))
            return PR_FALSE;

        schemeStr = buffer;
        if (schemeStr.Equals("blank")) {
            return PR_FALSE;
        }
    }
    return PR_TRUE;
}

nsresult
nsDocShell::AddToSessionHistory(nsIURI * aURI,
                                nsIChannel * aChannel, nsISHEntry ** aNewEntry)
{
    nsresult rv = NS_OK;
    nsCOMPtr<nsISHEntry> entry;
    PRBool shouldPersist;

    shouldPersist = ShouldAddToSessionHistory(aURI);

    //
    // If the entry is being replaced in SH, then just use the
    // current entry...
    //
    if (LOAD_NORMAL_REPLACE == mLoadType) {
        // There is no need to go to mSessionHistory and get the entry at
        // current index. OSHE works for subframes and top level docshells.
        entry = OSHE;
        // If there are children for this entry destroy them, as they are
        // going out of scope. 
        if (entry) {
            nsCOMPtr<nsISHContainer> shContainer(do_QueryInterface(entry));
            if (shContainer) {
                PRInt32 childCount = 0;
                shContainer->GetChildCount(&childCount);
                // Remove all children of this entry 
                for (PRInt32 i = childCount - 1; i >= 0; i--) {
                    nsCOMPtr<nsISHEntry> child;
                    shContainer->GetChildAt(i, getter_AddRefs(child));
                    shContainer->RemoveChild(child);
                }
            }
        }
    }

    // Create a new entry if necessary.
    if (!entry) {
        entry = do_CreateInstance(NS_SHENTRY_CONTRACTID);

        if (!entry) {
            return NS_ERROR_OUT_OF_MEMORY;
        }
    }

    // Get the post data & referrer
    nsCOMPtr<nsIInputStream> inputStream;
    nsCOMPtr<nsIURI> referrerURI;
    nsCOMPtr<nsISupports> cacheKey;
    if (aChannel) {
        nsCOMPtr<nsICachingChannel>
            cacheChannel(do_QueryInterface(aChannel));
        /* If there is a caching channel, get the Cache Key  and store it 
         * in SH.
         */
        if (cacheChannel) {
            cacheChannel->GetCacheKey(getter_AddRefs(cacheKey));
        }
        nsCOMPtr<nsIHTTPChannel> httpChannel(do_QueryInterface(aChannel));

        if (httpChannel) {
            httpChannel->GetUploadStream(getter_AddRefs(inputStream));
            httpChannel->GetReferrer(getter_AddRefs(referrerURI));
        }
    }

    //Title is set in nsDocShell::SetTitle()
    entry->Create(aURI,         // uri
                  nsnull,       // Title
                  nsnull,       // DOMDocument
                  inputStream,  // Post data stream
                  nsnull,       // LayoutHistory state
                  cacheKey);    // CacheKey
    entry->SetReferrerURI(referrerURI);


    // If no Session History component is available in the parent DocShell
    // heirarchy, then AddChildSHEntry(...) will fail and the new entry
    // will be deleted when it loses scope...
    //
    if (mLoadType != LOAD_NORMAL_REPLACE) {
        if (mSessionHistory) {
            nsCOMPtr<nsISHistoryInternal>
                shPrivate(do_QueryInterface(mSessionHistory));
            NS_ENSURE_TRUE(shPrivate, NS_ERROR_FAILURE);
            rv = shPrivate->AddEntry(entry, shouldPersist);
        }
        else
            rv = AddChildSHEntry(nsnull, entry, mChildOffset);
    }

    // Return the new SH entry...
    if (aNewEntry) {
        *aNewEntry = nsnull;
        if (NS_SUCCEEDED(rv)) {
            *aNewEntry = entry;
            NS_ADDREF(*aNewEntry);
        }
    }

    return rv;
}


NS_IMETHODIMP
nsDocShell::LoadHistoryEntry(nsISHEntry * aEntry, PRUint32 aLoadType)
{
    nsCOMPtr<nsIURI> uri;
    nsCOMPtr<nsIInputStream> postData;
    nsCOMPtr<nsIURI> referrerURI;

    NS_ENSURE_TRUE(aEntry, NS_ERROR_FAILURE);
    nsCOMPtr<nsIHistoryEntry> hEntry(do_QueryInterface(aEntry));
    NS_ENSURE_TRUE(hEntry, NS_ERROR_FAILURE);

    NS_ENSURE_SUCCESS(hEntry->GetURI(getter_AddRefs(uri)), NS_ERROR_FAILURE);
    NS_ENSURE_SUCCESS(aEntry->GetReferrerURI(getter_AddRefs(referrerURI)),
                      NS_ERROR_FAILURE);
    NS_ENSURE_SUCCESS(aEntry->GetPostData(getter_AddRefs(postData)),
                      NS_ERROR_FAILURE);

    NS_ENSURE_SUCCESS(InternalLoad
                      (uri, referrerURI, nsnull, PR_TRUE, PR_FALSE, nsnull,
                       postData, nsnull, aLoadType, aEntry), NS_ERROR_FAILURE);
    return NS_OK;
}


NS_IMETHODIMP nsDocShell::PersistLayoutHistoryState()
{
    nsresult
        rv =
        NS_OK;
    if (OSHE) {
        nsCOMPtr<nsIPresShell> shell;

        rv = GetPresShell(getter_AddRefs(shell));
        if (NS_SUCCEEDED(rv) && shell) {
            nsCOMPtr<nsILayoutHistoryState> layoutState;
            rv = shell->CaptureHistoryState(getter_AddRefs(layoutState),
                                            PR_TRUE);
            if (NS_SUCCEEDED(rv) && layoutState) {
                rv = OSHE->SetLayoutHistoryState(layoutState);
            }
        }

    }
    return rv;
}

NS_IMETHODIMP
nsDocShell::CloneAndReplace(nsISHEntry * src, PRUint32 aCloneID,
                            nsISHEntry * replaceEntry,
                            nsISHEntry ** resultEntry)
{
    nsresult result = NS_OK;
    NS_ENSURE_ARG_POINTER(resultEntry);
    nsISHEntry *dest = (nsISHEntry *) nsnull;
    PRUint32 srcID;
    src->GetID(&srcID);
    nsCOMPtr<nsIHistoryEntry> srcHE(do_QueryInterface(src));

    if (!src || !replaceEntry || !srcHE)
        return NS_ERROR_FAILURE;

    if (srcID == aCloneID) {
        dest = replaceEntry;
        dest->SetIsSubFrame(PR_TRUE);
        *resultEntry = dest;
        NS_IF_ADDREF(*resultEntry);
    }
    else {
        nsCOMPtr<nsIURI> uri;
        nsCOMPtr<nsIInputStream> postdata;
        nsCOMPtr<nsILayoutHistoryState> LHS;
        nsCOMPtr<nsIURI> referrerURI;
        PRUnichar *title = nsnull;
        nsCOMPtr<nsISHEntry> parent;
        PRUint32 id;
        result = nsComponentManager::CreateInstance(NS_SHENTRY_CONTRACTID, NULL,
                                                    NS_GET_IID(nsISHEntry),
                                                    (void **) &dest);
        if (!NS_SUCCEEDED(result))
            return result;

        srcHE->GetURI(getter_AddRefs(uri));
        src->GetReferrerURI(getter_AddRefs(referrerURI));
        src->GetPostData(getter_AddRefs(postdata));
        srcHE->GetTitle(&title);
        src->GetLayoutHistoryState(getter_AddRefs(LHS));
        //XXX Is this correct? parent is a weak ref in nsISHEntry
        src->GetParent(getter_AddRefs(parent));
        src->GetID(&id);

        // XXX do we care much about valid values for these uri, title etc....
        dest->SetURI(uri);
        dest->SetReferrerURI(referrerURI);
        dest->SetPostData(postdata);
        dest->SetLayoutHistoryState(LHS);
        dest->SetTitle(title);
        dest->SetParent(parent);
        dest->SetID(id);
        dest->SetIsSubFrame(PR_TRUE);
        *resultEntry = dest;

        PRInt32 childCount = 0;

        nsCOMPtr<nsISHContainer> srcContainer(do_QueryInterface(src));
        if (!srcContainer)
            return NS_ERROR_FAILURE;
        nsCOMPtr<nsISHContainer> destContainer(do_QueryInterface(dest));
        if (!destContainer)
            return NS_ERROR_FAILURE;
        srcContainer->GetChildCount(&childCount);
        for (PRInt32 i = 0; i < childCount; i++) {
            nsCOMPtr<nsISHEntry> srcChild;
            srcContainer->GetChildAt(i, getter_AddRefs(srcChild));
            if (!srcChild)
                return NS_ERROR_FAILURE;
            nsCOMPtr<nsISHEntry> destChild;
            if (!NS_SUCCEEDED(result))
                return result;
            result =
                CloneAndReplace(srcChild, aCloneID, replaceEntry,
                                getter_AddRefs(destChild));
            if (!NS_SUCCEEDED(result))
                return result;
            result = destContainer->AddChild(destChild, i);
            if (!NS_SUCCEEDED(result))
                return result;
        }                       // for 
    }

    return result;

}

//*****************************************************************************
// nsDocShell: Global History
//*****************************************************************************   

NS_IMETHODIMP
nsDocShell::ShouldAddToGlobalHistory(nsIURI * aURI, PRBool * aShouldAdd)
{
    *aShouldAdd = PR_FALSE;
    if (!mGlobalHistory || !aURI || (typeContent != mItemType))
        return NS_OK;

    // The model is really if we don't know differently then add which basically
    // means we are suppose to try all the things we know not to allow in and
    // then if we don't bail go on and allow it in.  But here lets compare
    // against the most common case we know to allow in and go on and say yes
    // to it.
    PRBool isHTTP = PR_FALSE;
    PRBool isHTTPS = PR_FALSE;
    NS_ENSURE_SUCCESS(aURI->SchemeIs("http", &isHTTP), NS_ERROR_FAILURE);
    NS_ENSURE_SUCCESS(aURI->SchemeIs("https", &isHTTPS), NS_ERROR_FAILURE);

    if (isHTTP || isHTTPS) {
        *aShouldAdd = PR_TRUE;
        return NS_OK;
    }

    PRBool isAbout = PR_FALSE;
    PRBool isImap = PR_FALSE;
    PRBool isNews = PR_FALSE;
    PRBool isMailbox = PR_FALSE;
    PRBool isViewSource = PR_FALSE;

    NS_ENSURE_SUCCESS(aURI->SchemeIs("about", &isAbout), NS_ERROR_FAILURE);
    NS_ENSURE_SUCCESS(aURI->SchemeIs("imap", &isImap), NS_ERROR_FAILURE);
    NS_ENSURE_SUCCESS(aURI->SchemeIs("news", &isNews), NS_ERROR_FAILURE);
    NS_ENSURE_SUCCESS(aURI->SchemeIs("mailbox", &isMailbox), NS_ERROR_FAILURE);
    NS_ENSURE_SUCCESS(aURI->SchemeIs("view-source", &isViewSource),
                      NS_ERROR_FAILURE);

    if (isAbout || isImap || isNews || isMailbox || isViewSource)
        return NS_OK;

    *aShouldAdd = PR_TRUE;
    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::AddToGlobalHistory(nsIURI * aURI)
{
    NS_ENSURE_STATE(mGlobalHistory);

    nsXPIDLCString spec;
    NS_ENSURE_SUCCESS(aURI->GetSpec(getter_Copies(spec)), NS_ERROR_FAILURE);

    NS_ENSURE_SUCCESS(mGlobalHistory->AddPage(spec), NS_ERROR_FAILURE);

    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::UpdateCurrentGlobalHistory()
{
    // XXX Add code here that needs to update the current history item
    return NS_OK;
}

//*****************************************************************************
// nsDocShell: Helper Routines
//*****************************************************************************   

nsresult
nsDocShell::SetLoadCookie(nsISupports * aCookie)
{
    // Remove the DocShell as a listener of the old WebProgress...
    if (mLoadCookie) {
        nsCOMPtr<nsIWebProgress> webProgress(do_QueryInterface(mLoadCookie));

        if (webProgress) {
            webProgress->RemoveProgressListener(this);
        }
    }

    mLoadCookie = aCookie;

    // Add the DocShell as a listener to the new WebProgress...
    if (mLoadCookie) {
        nsCOMPtr<nsIWebProgress> webProgress(do_QueryInterface(mLoadCookie));

        if (webProgress) {
            webProgress->AddProgressListener(this);
        }
    }
    return NS_OK;
}


nsresult
nsDocShell::GetLoadCookie(nsISupports ** aResult)
{
    *aResult = mLoadCookie;
    NS_IF_ADDREF(*aResult);

    return NS_OK;
}

nsresult
nsDocShell::SetLoadType(PRUint32 aLoadType)
{
    mLoadType = aLoadType;
    return NS_OK;
}


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

#define DIALOG_STRING_URI "chrome://global/locale/appstrings.properties"

NS_IMETHODIMP
nsDocShell::GetPromptAndStringBundle(nsIPrompt ** aPrompt,
                                     nsIStringBundle ** aStringBundle)
{
    NS_ENSURE_SUCCESS(GetInterface(NS_GET_IID(nsIPrompt), (void **) aPrompt),
                      NS_ERROR_FAILURE);

    nsCOMPtr<nsIStringBundleService>
        stringBundleService(do_GetService(NS_STRINGBUNDLE_CONTRACTID));
    NS_ENSURE_TRUE(stringBundleService, NS_ERROR_FAILURE);

    NS_ENSURE_SUCCESS(stringBundleService->
                      CreateBundle(DIALOG_STRING_URI,
                                   getter_AddRefs(aStringBundle)),
                      NS_ERROR_FAILURE);

    return NS_OK;
}

NS_IMETHODIMP
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;
}

NS_IMETHODIMP
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);

    if (*aOutScrollView == nsnull) {
        return NS_ERROR_FAILURE;
    }
    return NS_OK;
}

NS_IMETHODIMP
nsDocShell::EnsureContentListener()
{
    nsresult rv = NS_OK;
    if (mContentListener)
        return NS_OK;

    mContentListener = new nsDSURIContentListener();
    NS_ENSURE_TRUE(mContentListener, NS_ERROR_OUT_OF_MEMORY);

    NS_ADDREF(mContentListener);

    rv = mContentListener->Init();
    if (NS_FAILED(rv))
        return rv;

    mContentListener->DocShell(this);

    return NS_OK;
}

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

    NS_NewScriptGlobalObject(getter_AddRefs(mScriptGlobal));
    NS_ENSURE_TRUE(mScriptGlobal, NS_ERROR_FAILURE);

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

    NS_CreateScriptContext(mScriptGlobal, getter_AddRefs(mScriptContext));
    NS_ENSURE_TRUE(mScriptContext, NS_ERROR_FAILURE);

    return NS_OK;
}

NS_IMETHODIMP nsDocShell::EnsureFind()
{
    nsresult rv;
    if (!mFind)
    {
        mFind = do_CreateInstance("@mozilla.org/embedcomp/find;1", &rv);
        if (NS_FAILED(rv)) return rv;
    }
    
    // we promise that the nsIWebBrowserFind that we return has been set
    // up to point to the focussed, or content window, so we have to
    // set that up each time.
    nsCOMPtr<nsIScriptGlobalObject> scriptGO;
    rv = GetScriptGlobalObject(getter_AddRefs(scriptGO));
    if (NS_FAILED(rv)) return rv;

    // default to our window
    nsCOMPtr<nsIDOMWindow> rootWindow = do_QueryInterface(scriptGO);
    nsCOMPtr<nsIDOMWindow> windowToSearch = rootWindow;

    // if we can, search the focussed window
    nsCOMPtr<nsPIDOMWindow> ourWindow = do_QueryInterface(scriptGO);
    nsCOMPtr<nsIFocusController> focusController;
    if (ourWindow)
        ourWindow->GetRootFocusController(getter_AddRefs(focusController));
    if (focusController)
    {
        nsCOMPtr<nsIDOMWindowInternal> focussedWindow;
        focusController->GetFocusedWindow(getter_AddRefs(focussedWindow));
        if (focussedWindow)
        {
            rootWindow = focussedWindow;            // constrain to the focussed window.
            windowToSearch = focussedWindow;
        }
    }

    nsCOMPtr<nsIWebBrowserFindInFrames> findInFrames = do_QueryInterface(mFind);
    if (!findInFrames) return NS_ERROR_NO_INTERFACE;
    
    rv = findInFrames->SetRootSearchFrame(rootWindow);
    if (NS_FAILED(rv)) return rv;
    rv = findInFrames->SetCurrentSearchFrame(windowToSearch);
    if (NS_FAILED(rv)) return rv;
    
    return NS_OK;
}

PRBool
nsDocShell::IsFrame()
{
    if (mParent) {
        PRInt32 parentType = ~mItemType;        // Not us
        mParent->GetItemType(&parentType);
        if (parentType == mItemType)    // This is a frame
            return PR_TRUE;
    }

    return PR_FALSE;
}

//*****************************************************************************
//***    nsRefreshTimer: Object Management
//*****************************************************************************

nsRefreshTimer::nsRefreshTimer():mRepeat(PR_FALSE), mDelay(0),
mMetaRefresh(PR_FALSE)
{
    NS_INIT_REFCNT();
}

nsRefreshTimer::~nsRefreshTimer()
{
}

//*****************************************************************************
// nsRefreshTimer::nsISupports
//*****************************************************************************   

NS_IMPL_THREADSAFE_ADDREF(nsRefreshTimer)
NS_IMPL_THREADSAFE_RELEASE(nsRefreshTimer)

NS_INTERFACE_MAP_BEGIN(nsRefreshTimer)
    NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsITimerCallback)
    NS_INTERFACE_MAP_ENTRY(nsITimerCallback)
NS_INTERFACE_MAP_END_THREADSAFE

///*****************************************************************************
// nsRefreshTimer::nsITimerCallback
//*****************************************************************************   
NS_IMETHODIMP_(void)
nsRefreshTimer::Notify(nsITimer * aTimer)
{
    NS_ASSERTION(mDocShell, "DocShell is somehow null");

    if (mDocShell && aTimer) {
        // Get the delay count
        PRUint32 delay;
        delay = aTimer->GetDelay();
        // Get the current uri from the docshell.
        nsCOMPtr<nsIWebNavigation> webNav(do_QueryInterface(mDocShell));
        nsCOMPtr<nsIURI> currURI;
        if (webNav) {
            webNav->GetCurrentURI(getter_AddRefs(currURI));
        }
        nsCOMPtr<nsIDocShellLoadInfo> loadInfo;
        mDocShell->CreateLoadInfo(getter_AddRefs(loadInfo));
        /* Check if this META refresh causes a redirection
         * to another site. If so, check if this is permitted. Some
         * embedded applications may not want to do this.
         */
        PRBool equalUri = PR_FALSE;
        nsresult rv = mURI->Equals(currURI, &equalUri);
        if (NS_SUCCEEDED(rv) && (!equalUri) && mMetaRefresh) {
            PRBool allowRedirects = PR_TRUE;
            mDocShell->GetAllowMetaRedirects(&allowRedirects);
            if (!allowRedirects)
                return;
            /* It is a META refresh based redirection. Now check if it happened within 
             * the threshold time we have in mind(15000 ms as defined by REFRESH_REDIRECT_TIMER).
             * If so, pass a REPLACE flag to LoadURI().
             */
            if (delay <= REFRESH_REDIRECT_TIMER) {
                loadInfo->SetLoadType(nsIDocShellLoadInfo::loadNormalReplace);
            }
            else
                loadInfo->SetLoadType(nsIDocShellLoadInfo::loadRefresh);
            /*
             * LoadURL(...) will cancel all refresh timers... This causes the Timer and
             * its refreshData instance to be released...
             */
            mDocShell->LoadURI(mURI, loadInfo,
                               nsIWebNavigation::LOAD_FLAGS_NONE);
            return;

        }
        else
            loadInfo->SetLoadType(nsIDocShellLoadInfo::loadRefresh);
        mDocShell->LoadURI(mURI, loadInfo, nsIWebNavigation::LOAD_FLAGS_NONE);
    }
}