gecko-dev/docshell/base/nsDocShell.h

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 * vim: set ts=4 sw=4 et tw=80:
 *
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * 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 the Initial Developer are Copyright (C) 1999
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Travis Bogard <travis@netscape.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#ifndef nsDocShell_h__
#define nsDocShell_h__

#include "nsIPresShell.h"
#include "nsIDOMNode.h"
#include "nsIDOMNodeList.h"
#include "nsIViewManager.h"
#include "nsIScrollableView.h"
#include "nsIContentViewer.h"
#include "nsIPrefBranch.h"
#include "nsVoidArray.h"
#include "nsIScriptContext.h"
#include "nsITimer.h"

#include "nsCDocShell.h"
#include "nsIDocShellTreeOwner.h"
#include "nsIContentViewerContainer.h"
#include "nsIDeviceContext.h"

#include "nsDocLoader.h"
#include "nsIURILoader.h"
#include "nsIEditorDocShell.h"

#include "nsWeakReference.h"

// Local Includes
#include "nsDSURIContentListener.h"
#include "nsDocShellEditorData.h"

// Helper Classes
#include "nsCOMPtr.h"
#include "nsPoint.h" // mCurrent/mDefaultScrollbarPreferences
#include "nsString.h"
#include "nsAutoPtr.h"

// Threshold value in ms for META refresh based redirects
#define REFRESH_REDIRECT_TIMER 15000

// Interfaces Needed
#include "nsIDocumentCharsetInfo.h"
#include "nsIDocCharset.h"
#include "nsIGlobalHistory2.h"
#include "nsIInterfaceRequestor.h"
#include "nsIInterfaceRequestorUtils.h"
#include "nsIPrompt.h"
#include "nsIRefreshURI.h"
#include "nsIScriptGlobalObject.h"
#include "nsIScriptGlobalObjectOwner.h"
#include "nsISHistory.h"
#include "nsILayoutHistoryState.h"
#include "nsIStringBundle.h"
#include "nsISupportsArray.h"
#include "nsIWebNavigation.h"
#include "nsIWebPageDescriptor.h"
#include "nsIWebProgressListener.h"
#include "nsISHContainer.h"
#include "nsIDocShellLoadInfo.h"
#include "nsIDocShellHistory.h"
#include "nsIURIFixup.h"
#include "nsIWebBrowserFind.h"
#include "nsIHttpChannel.h"
#include "nsDocShellTransferableHooks.h"
#include "nsIAuthPromptProvider.h"
#include "nsISecureBrowserUI.h"
#include "nsIObserver.h"

/**
 * Load flag for error pages. This should be bigger than all flags on
 * nsIWebNavigation.
 */
#define LOAD_FLAGS_ERROR_PAGE 0x8000U

#define MAKE_LOAD_TYPE(type, flags) ((type) | ((flags) << 16))
#define LOAD_TYPE_HAS_FLAGS(type, flags) ((type) & ((flags) << 16))

/* load commands were moved to nsIDocShell.h */

/* load types are legal combinations of load commands and flags 
 *  
 * NOTE:
 *  Remember to update the IsValidLoadType function below if you change this
 *  enum to ensure bad flag combinations will be rejected.
 */
enum LoadType {
    LOAD_NORMAL = MAKE_LOAD_TYPE(nsIDocShell::LOAD_CMD_NORMAL, nsIWebNavigation::LOAD_FLAGS_NONE),
    LOAD_NORMAL_REPLACE = MAKE_LOAD_TYPE(nsIDocShell::LOAD_CMD_NORMAL, nsIWebNavigation::LOAD_FLAGS_REPLACE_HISTORY),
    LOAD_NORMAL_EXTERNAL = MAKE_LOAD_TYPE(nsIDocShell::LOAD_CMD_NORMAL, nsIWebNavigation::LOAD_FLAGS_FROM_EXTERNAL),
    LOAD_HISTORY = MAKE_LOAD_TYPE(nsIDocShell::LOAD_CMD_HISTORY, nsIWebNavigation::LOAD_FLAGS_NONE),
    LOAD_RELOAD_NORMAL = MAKE_LOAD_TYPE(nsIDocShell::LOAD_CMD_RELOAD, nsIWebNavigation::LOAD_FLAGS_NONE),
    LOAD_RELOAD_BYPASS_CACHE = MAKE_LOAD_TYPE(nsIDocShell::LOAD_CMD_RELOAD, nsIWebNavigation::LOAD_FLAGS_BYPASS_CACHE),
    LOAD_RELOAD_BYPASS_PROXY = MAKE_LOAD_TYPE(nsIDocShell::LOAD_CMD_RELOAD, nsIWebNavigation::LOAD_FLAGS_BYPASS_PROXY),
    LOAD_RELOAD_BYPASS_PROXY_AND_CACHE = MAKE_LOAD_TYPE(nsIDocShell::LOAD_CMD_RELOAD, nsIWebNavigation::LOAD_FLAGS_BYPASS_CACHE | nsIWebNavigation::LOAD_FLAGS_BYPASS_PROXY),
    LOAD_LINK = MAKE_LOAD_TYPE(nsIDocShell::LOAD_CMD_NORMAL, nsIWebNavigation::LOAD_FLAGS_IS_LINK),
    LOAD_REFRESH = MAKE_LOAD_TYPE(nsIDocShell::LOAD_CMD_NORMAL, nsIWebNavigation::LOAD_FLAGS_IS_REFRESH),
    LOAD_RELOAD_CHARSET_CHANGE = MAKE_LOAD_TYPE(nsIDocShell::LOAD_CMD_RELOAD, nsIWebNavigation::LOAD_FLAGS_CHARSET_CHANGE),
    LOAD_BYPASS_HISTORY = MAKE_LOAD_TYPE(nsIDocShell::LOAD_CMD_NORMAL, nsIWebNavigation::LOAD_FLAGS_BYPASS_HISTORY),
    LOAD_STOP_CONTENT = MAKE_LOAD_TYPE(nsIDocShell::LOAD_CMD_NORMAL, nsIWebNavigation::LOAD_FLAGS_STOP_CONTENT),
    LOAD_STOP_CONTENT_AND_REPLACE = MAKE_LOAD_TYPE(nsIDocShell::LOAD_CMD_NORMAL, nsIWebNavigation::LOAD_FLAGS_STOP_CONTENT | nsIWebNavigation::LOAD_FLAGS_REPLACE_HISTORY),
    /**
     * Load type for an error page. These loads are never triggered by users of
     * Docshell. Instead, Docshell triggers the load itself when a
     * consumer-triggered load failed.
     */
    LOAD_ERROR_PAGE = MAKE_LOAD_TYPE(nsIDocShell::LOAD_CMD_NORMAL, LOAD_FLAGS_ERROR_PAGE)

    // NOTE: Adding a new value? Remember to update IsValidLoadType!
};
static inline PRBool IsValidLoadType(PRUint32 aLoadType)
{
    switch (aLoadType)
    {
    case LOAD_NORMAL:
    case LOAD_NORMAL_REPLACE:
    case LOAD_NORMAL_EXTERNAL:
    case LOAD_HISTORY:
    case LOAD_RELOAD_NORMAL:
    case LOAD_RELOAD_BYPASS_CACHE:
    case LOAD_RELOAD_BYPASS_PROXY:
    case LOAD_RELOAD_BYPASS_PROXY_AND_CACHE:
    case LOAD_LINK:
    case LOAD_REFRESH:
    case LOAD_RELOAD_CHARSET_CHANGE:
    case LOAD_BYPASS_HISTORY:
    case LOAD_STOP_CONTENT:
    case LOAD_STOP_CONTENT_AND_REPLACE:
    case LOAD_ERROR_PAGE:
        return PR_TRUE;
    }
    return PR_FALSE;
}

/* internally used ViewMode types */
enum ViewMode {
    viewNormal = 0x0,
    viewSource = 0x1
};

//*****************************************************************************
//***    nsRefreshTimer
//*****************************************************************************

class nsRefreshTimer : public nsITimerCallback
{
public:
    nsRefreshTimer();

    NS_DECL_ISUPPORTS
    NS_DECL_NSITIMERCALLBACK

    PRInt32 GetDelay() { return mDelay ;}

    nsCOMPtr<nsIDocShell> mDocShell;
    nsCOMPtr<nsIURI>      mURI;
    PRInt32               mDelay;
    PRPackedBool          mRepeat;
    PRPackedBool          mMetaRefresh;
    
protected:
    virtual ~nsRefreshTimer();
};

//*****************************************************************************
//***    nsDocShell
//*****************************************************************************

class nsDocShell : public nsDocLoader,
                   public nsIDocShell,
                   public nsIDocShellTreeItem, 
                   public nsIDocShellTreeNode,
                   public nsIDocShellHistory,
                   public nsIWebNavigation,
                   public nsIBaseWindow, 
                   public nsIScrollable, 
                   public nsITextScroll, 
                   public nsIDocCharset, 
                   public nsIContentViewerContainer,
                   public nsIScriptGlobalObjectOwner,
                   public nsIRefreshURI,
                   public nsIWebProgressListener,
                   public nsIEditorDocShell,
                   public nsIWebPageDescriptor,
                   public nsIAuthPromptProvider,
                   public nsIObserver
{
friend class nsDSURIContentListener;

public:
    // Object Management
    nsDocShell();

    virtual nsresult Init();

    NS_DECL_ISUPPORTS_INHERITED

    NS_DECL_NSIDOCSHELL
    NS_DECL_NSIDOCSHELLTREEITEM
    NS_DECL_NSIDOCSHELLTREENODE
    NS_DECL_NSIDOCSHELLHISTORY
    NS_DECL_NSIWEBNAVIGATION
    NS_DECL_NSIBASEWINDOW
    NS_DECL_NSISCROLLABLE
    NS_DECL_NSITEXTSCROLL
    NS_DECL_NSIDOCCHARSET
    NS_DECL_NSIINTERFACEREQUESTOR
    NS_DECL_NSIWEBPROGRESSLISTENER
    NS_DECL_NSIREFRESHURI
    NS_DECL_NSICONTENTVIEWERCONTAINER
    NS_DECL_NSIEDITORDOCSHELL
    NS_DECL_NSIWEBPAGEDESCRIPTOR
    NS_DECL_NSIAUTHPROMPTPROVIDER
    NS_DECL_NSIOBSERVER

    NS_IMETHOD Stop() {
        // Need this here because otherwise nsIWebNavigation::Stop
        // overrides the docloader's Stop()
        return nsDocLoader::Stop();
    }

    // Need to implement (and forward) nsISecurityEventSink, because
    // nsIWebProgressListener has methods with identical names...
    NS_FORWARD_NSISECURITYEVENTSINK(nsDocLoader::)

    nsDocShellInfoLoadType ConvertLoadTypeToDocShellLoadInfo(PRUint32 aLoadType);
    PRUint32 ConvertDocShellLoadInfoToLoadType(nsDocShellInfoLoadType aDocShellLoadType);

    // nsIScriptGlobalObjectOwner methods
    virtual nsIScriptGlobalObject* GetScriptGlobalObject();

    // Restores a cached presentation from history (mLSHE).
    // This method swaps out the content viewer and simulates loads for
    // subframes.  It then simulates the completion of the toplevel load.
    nsresult RestoreFromHistory();

protected:
    // Object Management
    virtual ~nsDocShell();
    virtual void DestroyChildren();

    // Content Viewer Management
    NS_IMETHOD EnsureContentViewer();
    NS_IMETHOD EnsureDeviceContext();
    nsresult CreateAboutBlankContentViewer();
    NS_IMETHOD CreateContentViewer(const char * aContentType, 
        nsIRequest * request, nsIStreamListener ** aContentHandler);
    NS_IMETHOD NewContentViewerObj(const char * aContentType, 
        nsIRequest * request, nsILoadGroup * aLoadGroup, 
        nsIStreamListener ** aContentHandler, nsIContentViewer ** aViewer);
    NS_IMETHOD SetupNewViewer(nsIContentViewer * aNewViewer);

    void SetupReferrerFromChannel(nsIChannel * aChannel);
    
    NS_IMETHOD GetEldestPresContext(nsPresContext** aPresContext);
    void GetCurrentDocumentOwner(nsISupports ** aOwner);
    virtual nsresult DoURILoad(nsIURI * aURI,
                               nsIURI * aReferrer,
                               PRBool aSendReferrer,
                               nsISupports * aOwner,
                               const char * aTypeHint,
                               nsIInputStream * aPostData,
                               nsIInputStream * aHeadersData,
                               PRBool firstParty,
                               nsIDocShell ** aDocShell,
                               nsIRequest ** aRequest);
    NS_IMETHOD AddHeadersToChannel(nsIInputStream * aHeadersData, 
                                  nsIChannel * aChannel);
    virtual nsresult DoChannelLoad(nsIChannel * aChannel,
                                   nsIURILoader * aURILoader);
    NS_IMETHOD ScrollIfAnchor(nsIURI * aURI, PRBool * aWasAnchor,
                              PRUint32 aLoadType, nscoord *cx, nscoord *cy);

    // Returns PR_TRUE if would have called FireOnLocationChange,
    // but did not because aFireOnLocationChange was false on entry.
    // In this case it is the caller's responsibility to ensure
    // FireOnLocationChange is called.
    // In all other cases PR_FALSE is returned.
    PRBool OnLoadingSite(nsIChannel * aChannel,
                         PRBool aFireOnLocationChange,
                         PRBool aAddToGlobalHistory = PR_TRUE);

    // Returns PR_TRUE if would have called FireOnLocationChange,
    // but did not because aFireOnLocationChange was false on entry.
    // In this case it is the caller's responsibility to ensure
    // FireOnLocationChange is called.
    // In all other cases PR_FALSE is returned.
    PRBool OnNewURI(nsIURI * aURI, nsIChannel * aChannel, PRUint32 aLoadType,
                    PRBool aFireOnLocationChange,
                    PRBool aAddToGlobalHistory = PR_TRUE);

    virtual void SetReferrerURI(nsIURI * aURI);

    // Session History
    virtual PRBool ShouldAddToSessionHistory(nsIURI * aURI);
    virtual nsresult AddToSessionHistory(nsIURI * aURI, nsIChannel * aChannel,
        nsISHEntry ** aNewEntry);
    nsresult DoAddChildSHEntry(nsISHEntry* aNewEntry, PRInt32 aChildOffset);

    NS_IMETHOD LoadHistoryEntry(nsISHEntry * aEntry, PRUint32 aLoadType);
    NS_IMETHOD PersistLayoutHistoryState();

    // Clone a session history tree for subframe navigation.
    // The tree rooted at |aSrcEntry| will be cloned into |aDestEntry|, except
    // for the entry with id |aCloneID|, which will be replaced with
    // |aReplaceEntry|.  |aSrcShell| is a (possibly null) docshell which
    // corresponds to |aSrcEntry| via its mLSHE or mOHE pointers, and will
    // have that pointer updated to point to the cloned history entry.
    static nsresult CloneAndReplace(nsISHEntry *aSrcEntry,
                                    nsDocShell *aSrcShell,
                                    PRUint32 aCloneID,
                                    nsISHEntry *aReplaceEntry,
                                    nsISHEntry **aDestEntry);

    // Child-walking callback for CloneAndReplace
    static nsresult CloneAndReplaceChild(nsISHEntry *aEntry,
                                         nsDocShell *aShell,
                                         PRInt32 aChildIndex, void *aData);

    nsresult GetRootSessionHistory(nsISHistory ** aReturn);
    nsresult GetHttpChannel(nsIChannel * aChannel, nsIHttpChannel ** aReturn);
    PRBool ShouldDiscardLayoutState(nsIHttpChannel * aChannel);

    // Determine whether this docshell corresponds to the given history entry,
    // via having a pointer to it in mOSHE or mLSHE.
    PRBool HasHistoryEntry(nsISHEntry *aEntry) const
    {
        return aEntry && (aEntry == mOSHE || aEntry == mLSHE);
    }

    // Update any pointers (mOSHE or mLSHE) to aOldEntry to point to aNewEntry
    void SwapHistoryEntries(nsISHEntry *aOldEntry, nsISHEntry *aNewEntry);

    // Call this method to swap in a new history entry to m[OL]SHE, rather than
    // setting it directly.  This completes the navigation in all docshells
    // in the case of a subframe navigation.
    void SetHistoryEntry(nsCOMPtr<nsISHEntry> *aPtr, nsISHEntry *aEntry);

    // Child-walking callback for SetHistoryEntry
    static nsresult SetChildHistoryEntry(nsISHEntry *aEntry,
                                         nsDocShell *aShell,
                                         PRInt32 aEntryIndex, void *aData);

    // Callback prototype for WalkHistoryEntries.
    // aEntry is the child history entry, aShell is its corresponding docshell,
    // aChildIndex is the child's index in its parent entry, and aData is
    // the opaque pointer passed to WalkHistoryEntries.
    typedef nsresult (*WalkHistoryEntriesFunc)(nsISHEntry *aEntry,
                                               nsDocShell *aShell,
                                               PRInt32 aChildIndex,
                                               void *aData);

    // For each child of aRootEntry, find the corresponding docshell which is
    // a child of aRootShell, and call aCallback.  The opaque pointer aData
    // is passed to the callback.
    static nsresult WalkHistoryEntries(nsISHEntry *aRootEntry,
                                       nsDocShell *aRootShell,
                                       WalkHistoryEntriesFunc aCallback,
                                       void *aData);

    // Global History
    nsresult AddToGlobalHistory(nsIURI * aURI, PRBool aRedirect, nsIURI * aReferrer);

    // Helper Routines
    NS_IMETHOD GetPromptAndStringBundle(nsIPrompt ** aPrompt,
        nsIStringBundle ** aStringBundle);
    NS_IMETHOD GetChildOffset(nsIDOMNode * aChild, nsIDOMNode * aParent,
        PRInt32 * aOffset);
    NS_IMETHOD GetRootScrollableView(nsIScrollableView ** aOutScrollView);
    NS_IMETHOD EnsureScriptEnvironment();
    NS_IMETHOD EnsureEditorData();
    nsresult   EnsureTransferableHookData();
    NS_IMETHOD EnsureFind();
    nsresult   RefreshURIFromQueue();
    NS_IMETHOD DisplayLoadError(nsresult aError, nsIURI *aURI,
                                const PRUnichar *aURL,
                                nsIChannel* aFailedChannel = nsnull);
    NS_IMETHOD LoadErrorPage(nsIURI *aURI, const PRUnichar *aURL,
                             const PRUnichar *aPage,
                             const PRUnichar *aDescription,
                             nsIChannel* aFailedChannel);
    PRBool IsPrintingOrPP(PRBool aDisplayErrorDialog = PR_TRUE);

    nsresult SetBaseUrlForWyciwyg(nsIContentViewer * aContentViewer);

    static  inline  PRUint32
    PRTimeToSeconds(PRTime t_usec)
    {
      PRTime usec_per_sec;
      PRUint32 t_sec;
      LL_I2L(usec_per_sec, PR_USEC_PER_SEC);
      LL_DIV(t_usec, t_usec, usec_per_sec);
      LL_L2I(t_sec, t_usec);
      return t_sec;
    }

    nsresult FindTarget(const PRUnichar *aTargetName,
                        PRBool *aIsNewWindow,
                        nsIDocShell **aResult);

    PRBool IsFrame();

    //
    // Helper method that is called when a new document (including any
    // sub-documents - ie. frames) has been completely loaded.
    //
    virtual nsresult EndPageLoad(nsIWebProgress * aProgress,
                                 nsIChannel * aChannel,
                                 nsresult aResult);

    nsresult CheckLoadingPermissions();

    // Security checks to prevent frameset spoofing.  See comments at
    // implementation sites.
    static PRBool CanAccessItem(nsIDocShellTreeItem* aTargetItem,
                                nsIDocShellTreeItem* aAccessingItem,
                                PRBool aConsiderOpener = PR_TRUE);
    static PRBool ValidateOrigin(nsIDocShellTreeItem* aOriginTreeItem,
                                 nsIDocShellTreeItem* aTargetTreeItem);

    // Returns PR_TRUE if would have called FireOnLocationChange,
    // but did not because aFireOnLocationChange was false on entry.
    // In this case it is the caller's responsibility to ensure
    // FireOnLocationChange is called.
    // In all other cases PR_FALSE is returned.
    PRBool SetCurrentURI(nsIURI *aURI, nsIRequest *aRequest,
                         PRBool aFireOnLocationChange);

    // The following methods deal with saving and restoring content viewers
    // in session history.

    // mContentViewer points to the current content viewer associated with
    // this docshell.  When loading a new document, the content viewer is
    // either destroyed or stored into a session history entry.  To make sure
    // that destruction happens in a controlled fashion, a given content viewer
    // is always owned in exactly one of these ways:
    //   1) The content viewer is active and owned by a docshell's
    //      mContentViewer.
    //   2) The content viewer is still being displayed while we begin loading
    //      a new document.  The content viewer is owned by the _new_
    //      content viewer's mPreviousViewer, and has a pointer to the
    //      nsISHEntry where it will eventually be stored.  The content viewer
    //      has been close()d by the docshell, which detaches the document from
    //      the window object.
    //   3) The content viewer is cached in session history.  The nsISHEntry
    //      has the only owning reference to the content viewer.  The viewer
    //      has released its nsISHEntry pointer to prevent circular ownership.
    //
    // When restoring a content viewer from session history, open() is called
    // to reattach the document to the window object.  The content viewer is
    // then placed into mContentViewer and removed from the history entry.
    // (mContentViewer is put into session history as described above, if
    // applicable).

    // Determines whether we can safely cache the current mContentViewer in
    // session history.  This checks a number of factors such as cache policy,
    // pending requests, and unload handlers.
    // |aLoadType| should be the load type that will replace the current
    // presentation.  |aNewRequest| should be the request for the document to
    // be loaded in place of the current document, or null if such a request
    // has not been created yet. |aNewDocument| should be the document that will
    // replace the current document.
    PRBool CanSavePresentation(PRUint32 aLoadType,
                               nsIRequest *aNewRequest,
                               nsIDocument *aNewDocument);

    // Captures the state of the supporting elements of the presentation
    // (the "window" object, docshell tree, meta-refresh loads, and security
    // state) and stores them on |mOSHE|.
    nsresult CaptureState();

    // Begin the toplevel restore process for |aSHEntry|.
    // This simulates a channel open, and defers the real work until
    // RestoreFromHistory is called from a PLEvent.
    nsresult RestorePresentation(nsISHEntry *aSHEntry, PRBool *aRestoring);

    // Call BeginRestore(nsnull, PR_FALSE) for each child of this shell.
    nsresult BeginRestoreChildren();

protected:
    // Override the parent setter from nsDocLoader
    virtual nsresult SetDocLoaderParent(nsDocLoader * aLoader);

    PRPackedBool               mAllowSubframes;
    PRPackedBool               mAllowPlugins;
    PRPackedBool               mAllowJavascript;
    PRPackedBool               mAllowMetaRedirects;
    PRPackedBool               mAllowImages;
    PRPackedBool               mFocusDocFirst;
    PRPackedBool               mHasFocus;
    PRPackedBool               mCreatingDocument; // (should be) debugging only
    PRPackedBool               mUseErrorPages;
    PRPackedBool               mObserveErrorPages;
    PRPackedBool               mAllowAuth;

    PRPackedBool               mFiredUnloadEvent;

    // this flag is for bug #21358. a docshell may load many urls
    // which don't result in new documents being created (i.e. a new
    // content viewer) we want to make sure we don't call a on load
    // event more than once for a given content viewer.
    PRPackedBool               mEODForCurrentDocument; 
    PRPackedBool               mURIResultedInDocument;

    PRPackedBool               mIsBeingDestroyed;

    PRPackedBool               mIsExecutingOnLoadHandler;

    // Indicates that a DocShell in this "docshell tree" is printing
    PRPackedBool               mIsPrintingOrPP;

    // Indicates to CreateContentViewer() that it is safe to cache the old
    // presentation of the page, and to SetupNewViewer() that the old viewer
    // should be passed a SHEntry to save itself into.
    PRPackedBool               mSavingOldViewer;

    PRUint32                   mAppType;

    // Offset in the parent's child list.
    PRInt32                    mChildOffset;

    PRUint32                   mBusyFlags;

    PRInt32                    mMarginWidth;
    PRInt32                    mMarginHeight;
    PRInt32                    mItemType;

    PRUint32                   mLoadType;

    nsString                   mName;
    nsString                   mTitle;
    /**
     * Content-Type Hint of the most-recently initiated load. Used for
     * session history entries.
     */
    nsCString                  mContentTypeHint;
    nsCOMPtr<nsISupportsArray> mRefreshURIList;
    nsCOMPtr<nsISupportsArray> mSavedRefreshURIList;
    nsRefPtr<nsDSURIContentListener> mContentListener;
    nsRect                     mBounds; // Dimensions of the docshell
    nsCOMPtr<nsIContentViewer> mContentViewer;
    nsCOMPtr<nsIDocumentCharsetInfo> mDocumentCharsetInfo;
    nsCOMPtr<nsIDeviceContext> mDeviceContext;
    nsCOMPtr<nsIWidget>        mParentWidget;
    nsCOMPtr<nsIPrefBranch>    mPrefs;
    nsCOMPtr<nsIURI>           mCurrentURI;
    nsCOMPtr<nsIURI>           mReferrerURI;
    nsCOMPtr<nsIScriptGlobalObject> mScriptGlobal;
    nsCOMPtr<nsISHistory>      mSessionHistory;
    nsCOMPtr<nsIGlobalHistory2> mGlobalHistory;
    nsCOMPtr<nsIWebBrowserFind> mFind;
    nsPoint                    mDefaultScrollbarPref; // persistent across doc loads
    // Reference to the SHEntry for this docshell until the page is destroyed.
    // Somebody give me better name
    nsCOMPtr<nsISHEntry>       mOSHE; 
    // Reference to the SHEntry for this docshell until the page is loaded
    // Somebody give me better name
    nsCOMPtr<nsISHEntry>       mLSHE;

    // Index into the SHTransaction list, indicating the previous and current
    // transaction at the time that this DocShell begins to load
    PRInt32                    mPreviousTransIndex;
    PRInt32                    mLoadedTransIndex;

    // Editor stuff
    nsDocShellEditorData*      mEditorData;          // editor data, if any

    // Transferable hooks/callbacks
    nsCOMPtr<nsIClipboardDragDropHookList>  mTransferableHookData;

    // Secure browser UI object
    nsCOMPtr<nsISecureBrowserUI> mSecurityUI;

    // WEAK REFERENCES BELOW HERE.
    // Note these are intentionally not addrefd.  Doing so will create a cycle.
    // For that reasons don't use nsCOMPtr.

    nsIDocShellTreeOwner *     mTreeOwner; // Weak Reference
    nsIChromeEventHandler *    mChromeEventHandler; //Weak Reference

    static nsIURIFixup *sURIFixup;


public:
    class InterfaceRequestorProxy : public nsIInterfaceRequestor {
    public:
        InterfaceRequestorProxy(nsIInterfaceRequestor* p);
        virtual ~InterfaceRequestorProxy();
        NS_DECL_ISUPPORTS
        NS_DECL_NSIINTERFACEREQUESTOR
 
    protected:
        InterfaceRequestorProxy() {}
        nsWeakPtr mWeakPtr;
    };
};

#endif /* nsDocShell_h__ */