layout/base/nsDocumentViewer.cpp
author Ms2ger <ms2ger@gmail.com>
Sat, 03 May 2014 09:34:00 +0200
changeset 181840 e50544d1d32d9d86f1db8a2c3338d5502773a402
parent 180884 6c1c7e45c90289a0875b74f82f39e7ecf6a65af3
permissions -rw-r--r--
Bug 1004202 - Stop calling PrepareToStartLoad in nsDocumentViewer::LoadStart; r=smaug Before bug 968805, none of the callers would reach this branch. The callers in nsContentDLF.cpp call LoadStart immediately after constructing the nsDocumentViewer, so they hit the !mDocument case, and the comparison was always false for the caller in nsHTMLDocument::Open, as it passed an nsIHTMLDocument pointer, so the nsISupports pointers being compared were always different. (XPCOM rules require SameCOMIdentity in this case, to avoid exactly this issue.) I tested that the removed code was never reached after a backout of bug 968805.

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=2 sw=2 et tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/* container for a document and its presentation */

#include "nscore.h"
#include "nsCOMPtr.h"
#include "nsCRT.h"
#include "nsString.h"
#include "nsReadableUtils.h"
#include "nsIContent.h"
#include "nsIContentViewerContainer.h"
#include "nsIContentViewer.h"
#include "nsIDocumentViewerPrint.h"
#include "nsIDOMBeforeUnloadEvent.h"
#include "nsIDocument.h"
#include "nsIDOMWindowUtils.h"
#include "nsPresContext.h"
#include "nsIPresShell.h"
#include "nsStyleSet.h"
#include "nsCSSStyleSheet.h"
#include "nsIFrame.h"
#include "nsIWritablePropertyBag2.h"
#include "nsSubDocumentFrame.h"

#include "nsILinkHandler.h"
#include "nsIDOMDocument.h"
#include "nsISelectionListener.h"
#include "nsISelectionPrivate.h"
#include "nsIDOMHTMLDocument.h"
#include "nsIDOMHTMLElement.h"
#include "nsContentUtils.h"
#include "nsLayoutStylesheetCache.h"
#ifdef ACCESSIBILITY
#include "mozilla/a11y/DocAccessible.h"
#endif
#include "mozilla/BasicEvents.h"
#include "mozilla/Preferences.h"
#include "mozilla/dom/EncodingUtils.h"
#include "mozilla/WeakPtr.h"

#include "nsViewManager.h"
#include "nsView.h"

#include "nsIPageSequenceFrame.h"
#include "nsNetUtil.h"
#include "nsIContentViewerEdit.h"
#include "nsIContentViewerFile.h"
#include "mozilla/css/Loader.h"
#include "nsIMarkupDocumentViewer.h"
#include "nsIInterfaceRequestor.h"
#include "nsIInterfaceRequestorUtils.h"
#include "nsDocShell.h"
#include "nsIBaseWindow.h"
#include "nsILayoutHistoryState.h"
#include "nsCharsetSource.h"
#include "nsHTMLReflowState.h"
#include "nsIImageLoadingContent.h"
#include "nsCopySupport.h"
#include "nsIDOMHTMLFrameSetElement.h"
#ifdef MOZ_XUL
#include "nsIXULDocument.h"
#include "nsXULPopupManager.h"
#endif

#include "nsIClipboardHelper.h"

#include "nsPIDOMWindow.h"
#include "nsDOMNavigationTiming.h"
#include "nsPIWindowRoot.h"
#include "nsJSEnvironment.h"
#include "nsFocusManager.h"

#include "nsIScrollableFrame.h"
#include "nsStyleSheetService.h"
#include "nsRenderingContext.h"
#include "nsILoadContext.h"

#include "nsIPrompt.h"
#include "imgIContainer.h" // image animation mode constants

//--------------------------
// Printing Include
//---------------------------
#ifdef NS_PRINTING

#include "nsIWebBrowserPrint.h"

#include "nsPrintEngine.h"

// Print Options
#include "nsIPrintSettings.h"
#include "nsIPrintOptions.h"
#include "nsISimpleEnumerator.h"

#ifdef DEBUG
// PrintOptions is now implemented by PrintSettingsService
static const char sPrintOptionsContractID[] =
  "@mozilla.org/gfx/printsettings-service;1";
#endif // DEBUG

#include "nsIPluginDocument.h"

#endif // NS_PRINTING

//focus
#include "nsIDOMEventTarget.h"
#include "nsIDOMEventListener.h"
#include "nsISelectionController.h"

#include "mozilla/EventDispatcher.h"
#include "nsISHEntry.h"
#include "nsISHistory.h"
#include "nsISHistoryInternal.h"
#include "nsIWebNavigation.h"
#include "nsXMLHttpRequest.h"

//paint forcing
#include <stdio.h>

#include "mozilla/dom/Element.h"

using namespace mozilla;
using namespace mozilla::dom;

#define BEFOREUNLOAD_DISABLED_PREFNAME "dom.disable_beforeunload"

//-----------------------------------------------------
// PR LOGGING
#ifdef MOZ_LOGGING
#define FORCE_PR_LOG /* Allow logging in the release build */
#endif

#include "prlog.h"

#ifdef PR_LOGGING

#ifdef NS_PRINTING
static PRLogModuleInfo *
GetPrintingLog()
{
  static PRLogModuleInfo *sLog;
  if (!sLog)
    sLog = PR_NewLogModule("printing");
  return sLog;
}
#define PR_PL(_p1)  PR_LOG(GetPrintingLog(), PR_LOG_DEBUG, _p1);
#endif // NS_PRINTING

#define PRT_YESNO(_p) ((_p)?"YES":"NO")
#else
#define PRT_YESNO(_p)
#define PR_PL(_p1)
#endif
//-----------------------------------------------------

class nsDocumentViewer;
class nsPrintEventDispatcher;

// a small delegate class used to avoid circular references

class nsDocViewerSelectionListener : public nsISelectionListener
{
public:

  // nsISupports interface...
  NS_DECL_ISUPPORTS

  // nsISelectionListerner interface
  NS_DECL_NSISELECTIONLISTENER

                       nsDocViewerSelectionListener()
                       : mDocViewer(nullptr)
                       , mGotSelectionState(false)
                       , mSelectionWasCollapsed(false)
                       {
                       }

  virtual              ~nsDocViewerSelectionListener() {}

  nsresult             Init(nsDocumentViewer *aDocViewer);

protected:

  nsDocumentViewer*  mDocViewer;
  bool                 mGotSelectionState;
  bool                 mSelectionWasCollapsed;

};


/** editor Implementation of the FocusListener interface
 */
class nsDocViewerFocusListener : public nsIDOMEventListener
{
public:
  /** default constructor
   */
  nsDocViewerFocusListener();
  /** default destructor
   */
  virtual ~nsDocViewerFocusListener();

  NS_DECL_ISUPPORTS
  NS_DECL_NSIDOMEVENTLISTENER

  nsresult             Init(nsDocumentViewer *aDocViewer);

private:
    nsDocumentViewer*  mDocViewer;
};


//-------------------------------------------------------------
class nsDocumentViewer : public nsIContentViewer,
                           public nsIContentViewerEdit,
                           public nsIContentViewerFile,
                           public nsIMarkupDocumentViewer,
                           public nsIDocumentViewerPrint

#ifdef NS_PRINTING
                           , public nsIWebBrowserPrint
#endif

{
  friend class nsDocViewerSelectionListener;
  friend class nsPagePrintTimer;
  friend class nsPrintEngine;

public:
  nsDocumentViewer();

  NS_DECL_AND_IMPL_ZEROING_OPERATOR_NEW

  // nsISupports interface...
  NS_DECL_ISUPPORTS

  // nsIContentViewer interface...
  NS_DECL_NSICONTENTVIEWER

  // nsIContentViewerEdit
  NS_DECL_NSICONTENTVIEWEREDIT

  // nsIContentViewerFile
  NS_DECL_NSICONTENTVIEWERFILE

  // nsIMarkupDocumentViewer
  NS_DECL_NSIMARKUPDOCUMENTVIEWER

#ifdef NS_PRINTING
  // nsIWebBrowserPrint
  NS_DECL_NSIWEBBROWSERPRINT
#endif

  typedef void (*CallChildFunc)(nsIMarkupDocumentViewer* aViewer,
                                void* aClosure);
  void CallChildren(CallChildFunc aFunc, void* aClosure);

  // nsIDocumentViewerPrint Printing Methods
  NS_DECL_NSIDOCUMENTVIEWERPRINT


  static void DispatchBeforePrint(nsIDocument* aTop)
  {
    DispatchEventToWindowTree(aTop, NS_LITERAL_STRING("beforeprint"));
  }
  static void DispatchAfterPrint(nsIDocument* aTop)
  {
    DispatchEventToWindowTree(aTop, NS_LITERAL_STRING("afterprint"));
  }
  static void DispatchEventToWindowTree(nsIDocument* aTop,
                                        const nsAString& aEvent);

protected:
  virtual ~nsDocumentViewer();

private:
  /**
   * Creates a view manager, root view, and widget for the root view, setting
   * mViewManager and mWindow.
   * @param aSize the initial size in appunits
   * @param aContainerView the container view to hook our root view up
   * to as a child, or null if this will be the root view manager
   */
  nsresult MakeWindow(const nsSize& aSize, nsView* aContainerView);

  /**
   * Create our device context
   */
  nsresult CreateDeviceContext(nsView* aContainerView);

  /**
   * If aDoCreation is true, this creates the device context, creates a
   * prescontext if necessary, and calls MakeWindow.
   *
   * If aForceSetNewDocument is false, then SetNewDocument won't be
   * called if the window's current document is already mDocument.
   */
  nsresult InitInternal(nsIWidget* aParentWidget,
                        nsISupports *aState,
                        const nsIntRect& aBounds,
                        bool aDoCreation,
                        bool aNeedMakeCX = true,
                        bool aForceSetNewDocument = true);
  /**
   * @param aDoInitialReflow set to true if you want to kick off the initial
   * reflow
   */
  nsresult InitPresentationStuff(bool aDoInitialReflow);

  nsresult GetPopupNode(nsIDOMNode** aNode);
  nsresult GetPopupLinkNode(nsIDOMNode** aNode);
  nsresult GetPopupImageNode(nsIImageLoadingContent** aNode);

  void PrepareToStartLoad(void);

  nsresult SyncParentSubDocMap();

  nsresult GetDocumentSelection(nsISelection **aSelection);

  void DestroyPresShell();
  void DestroyPresContext();

#ifdef NS_PRINTING
  // Called when the DocViewer is notified that the state
  // of Printing or PP has changed
  void SetIsPrintingInDocShellTree(nsIDocShellTreeItem* aParentNode, 
                                   bool                 aIsPrintingOrPP, 
                                   bool                 aStartAtTop);
#endif // NS_PRINTING

  // Whether we should attach to the top level widget. This is true if we
  // are sharing/recycling a single base widget and not creating multiple
  // child widgets.
  bool ShouldAttachToTopLevel();

protected:
  // These return the current shell/prescontext etc.
  nsIPresShell* GetPresShell();
  nsPresContext* GetPresContext();
  nsViewManager* GetViewManager();

  void DetachFromTopLevelWidget();

  // IMPORTANT: The ownership implicit in the following member
  // variables has been explicitly checked and set using nsCOMPtr
  // for owning pointers and raw COM interface pointers for weak
  // (ie, non owning) references. If you add any members to this
  // class, please make the ownership explicit (pinkerton, scc).

  WeakPtr<nsDocShell> mContainer; // it owns me!
  nsWeakPtr mTopContainerWhilePrinting;
  nsRefPtr<nsDeviceContext> mDeviceContext;  // We create and own this baby

  // the following six items are explicitly in this order
  // so they will be destroyed in the reverse order (pinkerton, scc)
  nsCOMPtr<nsIDocument>    mDocument;
  nsCOMPtr<nsIWidget>      mWindow;      // may be null
  nsRefPtr<nsViewManager> mViewManager;
  nsRefPtr<nsPresContext>  mPresContext;
  nsCOMPtr<nsIPresShell>   mPresShell;

  nsCOMPtr<nsISelectionListener> mSelectionListener;
  nsRefPtr<nsDocViewerFocusListener> mFocusListener;

  nsCOMPtr<nsIContentViewer> mPreviousViewer;
  nsCOMPtr<nsISHEntry> mSHEntry;

  nsIWidget* mParentWidget; // purposely won't be ref counted.  May be null
  bool mAttachedToParent; // view is attached to the parent widget

  nsIntRect mBounds;

  // mTextZoom/mPageZoom record the textzoom/pagezoom of the first (galley)
  // presshell only.
  float mTextZoom;      // Text zoom, defaults to 1.0
  float mPageZoom;
  int mMinFontSize;

  int16_t mNumURLStarts;
  int16_t mDestroyRefCount;    // a second "refcount" for the document viewer's "destroy"

  unsigned      mStopped : 1;
  unsigned      mLoaded : 1;
  unsigned      mDeferredWindowClose : 1;
  // document management data
  //   these items are specific to markup documents (html and xml)
  //   may consider splitting these out into a subclass
  unsigned      mIsSticky : 1;
  unsigned      mInPermitUnload : 1;
  unsigned      mInPermitUnloadPrompt: 1;

#ifdef NS_PRINTING
  unsigned      mClosingWhilePrinting : 1;

#if NS_PRINT_PREVIEW
  unsigned                         mPrintPreviewZoomed : 1;

  // These data members support delayed printing when the document is loading
  unsigned                         mPrintIsPending : 1;
  unsigned                         mPrintDocIsFullyLoaded : 1;
  nsCOMPtr<nsIPrintSettings>       mCachedPrintSettings;
  nsCOMPtr<nsIWebProgressListener> mCachedPrintWebProgressListner;

  nsRefPtr<nsPrintEngine>          mPrintEngine;
  float                            mOriginalPrintPreviewScale;
  float                            mPrintPreviewZoom;
  nsAutoPtr<nsPrintEventDispatcher> mBeforeAndAfterPrint;
#endif // NS_PRINT_PREVIEW

#ifdef DEBUG
  FILE* mDebugFile;
#endif // DEBUG
#endif // NS_PRINTING

  /* character set member data */
  int32_t mHintCharsetSource;
  nsCString mHintCharset;
  nsCString mForceCharacterSet;
  
  bool mIsPageMode;
  bool mCallerIsClosingWindow;
  bool mInitializedForPrintPreview;
  bool mHidden;
};

class nsPrintEventDispatcher
{
public:
  nsPrintEventDispatcher(nsIDocument* aTop) : mTop(aTop)
  {
    nsDocumentViewer::DispatchBeforePrint(mTop);
  }
  ~nsPrintEventDispatcher()
  {
    nsDocumentViewer::DispatchAfterPrint(mTop);
  }

  nsCOMPtr<nsIDocument> mTop;
};

class nsDocumentShownDispatcher : public nsRunnable
{
public:
  nsDocumentShownDispatcher(nsCOMPtr<nsIDocument> aDocument)
  : mDocument(aDocument) {}

  NS_IMETHOD Run() MOZ_OVERRIDE;

private:
  nsCOMPtr<nsIDocument> mDocument;
};


//------------------------------------------------------------------
// nsDocumentViewer
//------------------------------------------------------------------

//------------------------------------------------------------------
already_AddRefed<nsIContentViewer>
NS_NewContentViewer()
{
  nsRefPtr<nsDocumentViewer> viewer = new nsDocumentViewer();
  return viewer.forget();
}

void nsDocumentViewer::PrepareToStartLoad()
{
  mStopped          = false;
  mLoaded           = false;
  mAttachedToParent = false;
  mDeferredWindowClose = false;
  mCallerIsClosingWindow = false;

#ifdef NS_PRINTING
  mPrintIsPending        = false;
  mPrintDocIsFullyLoaded = false;
  mClosingWhilePrinting  = false;

  // Make sure we have destroyed it and cleared the data member
  if (mPrintEngine) {
    mPrintEngine->Destroy();
    mPrintEngine = nullptr;
#ifdef NS_PRINT_PREVIEW
    SetIsPrintPreview(false);
#endif
  }

#ifdef DEBUG
  mDebugFile = nullptr;
#endif

#endif // NS_PRINTING
}

// Note: operator new zeros our memory, so no need to init things to null.
nsDocumentViewer::nsDocumentViewer()
  : mTextZoom(1.0), mPageZoom(1.0), mMinFontSize(0),
    mIsSticky(true),
#ifdef NS_PRINT_PREVIEW
    mPrintPreviewZoom(1.0),
#endif
    mHintCharsetSource(kCharsetUninitialized),
    mInitializedForPrintPreview(false),
    mHidden(false)
{
  PrepareToStartLoad();
}

NS_IMPL_ADDREF(nsDocumentViewer)
NS_IMPL_RELEASE(nsDocumentViewer)

NS_INTERFACE_MAP_BEGIN(nsDocumentViewer)
    NS_INTERFACE_MAP_ENTRY(nsIContentViewer)
    NS_INTERFACE_MAP_ENTRY(nsIMarkupDocumentViewer)
    NS_INTERFACE_MAP_ENTRY(nsIContentViewerFile)
    NS_INTERFACE_MAP_ENTRY(nsIContentViewerEdit)
    NS_INTERFACE_MAP_ENTRY(nsIDocumentViewerPrint)
    NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIContentViewer)
#ifdef NS_PRINTING
    NS_INTERFACE_MAP_ENTRY(nsIWebBrowserPrint)
#endif
NS_INTERFACE_MAP_END

nsDocumentViewer::~nsDocumentViewer()
{
  if (mDocument) {
    Close(nullptr);
    mDocument->Destroy();
  }

  NS_ASSERTION(!mPresShell && !mPresContext,
               "User did not call nsIContentViewer::Destroy");
  if (mPresShell || mPresContext) {
    // Make sure we don't hand out a reference to the content viewer to
    // the SHEntry!
    mSHEntry = nullptr;

    Destroy();
  }

  // XXX(?) Revoke pending invalidate events
}

/*
 * This method is called by the Document Loader once a document has
 * been created for a particular data stream...  The content viewer
 * must cache this document for later use when Init(...) is called.
 *
 * This method is also called when an out of band document.write() happens.
 * In that case, the document passed in is the same as the previous document.
 */
/* virtual */ void
nsDocumentViewer::LoadStart(nsIDocument* aDocument)
{
  MOZ_ASSERT(aDocument);

  if (!mDocument) {
    mDocument = aDocument;
  }
}

nsresult
nsDocumentViewer::SyncParentSubDocMap()
{
  nsCOMPtr<nsIDocShellTreeItem> item(mContainer);
  nsCOMPtr<nsPIDOMWindow> pwin(do_GetInterface(item));
  nsCOMPtr<nsIContent> content;

  if (mDocument && pwin) {
    content = do_QueryInterface(pwin->GetFrameElementInternal());
  }

  if (content) {
    nsCOMPtr<nsIDocShellTreeItem> parent;
    item->GetParent(getter_AddRefs(parent));

    nsCOMPtr<nsIDOMWindow> parent_win(do_GetInterface(parent));

    if (parent_win) {
      nsCOMPtr<nsIDOMDocument> dom_doc;
      parent_win->GetDocument(getter_AddRefs(dom_doc));

      nsCOMPtr<nsIDocument> parent_doc(do_QueryInterface(dom_doc));

      if (parent_doc) {
        if (mDocument &&
            parent_doc->GetSubDocumentFor(content) != mDocument) {
          mDocument->SuppressEventHandling(nsIDocument::eEvents,
                                           parent_doc->EventHandlingSuppressed());
        }
        return parent_doc->SetSubDocumentFor(content->AsElement(), mDocument);
      }
    }
  }

  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::SetContainer(nsIDocShell* aContainer)
{
  mContainer = static_cast<nsDocShell*>(aContainer)->asWeakPtr();
  if (mPresContext) {
    mPresContext->SetContainer(mContainer);
  }

  // We're loading a new document into the window where this document
  // viewer lives, sync the parent document's frame element -> sub
  // document map

  return SyncParentSubDocMap();
}

NS_IMETHODIMP
nsDocumentViewer::GetContainer(nsIDocShell** aResult)
{
   NS_ENSURE_ARG_POINTER(aResult);

   nsCOMPtr<nsIDocShell> container(mContainer);
   container.swap(*aResult);
   return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::Init(nsIWidget* aParentWidget,
                         const nsIntRect& aBounds)
{
  return InitInternal(aParentWidget, nullptr, aBounds, true);
}

nsresult
nsDocumentViewer::InitPresentationStuff(bool aDoInitialReflow)
{
  if (GetIsPrintPreview())
    return NS_OK;

  NS_ASSERTION(!mPresShell,
               "Someone should have destroyed the presshell!");

  // Create the style set...
  nsStyleSet *styleSet;
  nsresult rv = CreateStyleSet(mDocument, &styleSet);
  NS_ENSURE_SUCCESS(rv, rv);

  // Now make the shell for the document
  mPresShell = mDocument->CreateShell(mPresContext, mViewManager, styleSet);
  if (!mPresShell) {
    delete styleSet;
    return NS_ERROR_FAILURE;
  }

  // We're done creating the style set
  styleSet->EndUpdate();

  if (aDoInitialReflow) {
    // Since Initialize() will create frames for *all* items
    // that are currently in the document tree, we need to flush
    // any pending notifications to prevent the content sink from
    // duplicating layout frames for content it has added to the tree
    // but hasn't notified the document about. (Bug 154018)
    //
    // Note that we are flushing before we add mPresShell as an observer
    // to avoid bogus notifications.

    mDocument->FlushPendingNotifications(Flush_ContentAndNotify);
  }

  mPresShell->BeginObservingDocument();

  // Initialize our view manager
  int32_t p2a = mPresContext->AppUnitsPerDevPixel();
  MOZ_ASSERT(p2a == mPresContext->DeviceContext()->UnscaledAppUnitsPerDevPixel());
  nscoord width = p2a * mBounds.width;
  nscoord height = p2a * mBounds.height;

  mViewManager->SetWindowDimensions(width, height);
  mPresContext->SetTextZoom(mTextZoom);
  mPresContext->SetFullZoom(mPageZoom);
  mPresContext->SetBaseMinFontSize(mMinFontSize);

  p2a = mPresContext->AppUnitsPerDevPixel();  // zoom may have changed it
  width = p2a * mBounds.width;
  height = p2a * mBounds.height;
  if (aDoInitialReflow) {
    nsCOMPtr<nsIPresShell> shellGrip = mPresShell;
    // Initial reflow
    mPresShell->Initialize(width, height);
  } else {
    // Store the visible area so it's available for other callers of
    // Initialize, like nsContentSink::StartLayout.
    mPresContext->SetVisibleArea(nsRect(0, 0, width, height));
  }

  // now register ourselves as a selection listener, so that we get
  // called when the selection changes in the window
  if (!mSelectionListener) {
    nsDocViewerSelectionListener *selectionListener =
      new nsDocViewerSelectionListener();

    selectionListener->Init(this);

    // mSelectionListener is a owning reference
    mSelectionListener = selectionListener;
  }

  nsCOMPtr<nsISelection> selection;
  rv = GetDocumentSelection(getter_AddRefs(selection));
  NS_ENSURE_SUCCESS(rv, rv);

  nsCOMPtr<nsISelectionPrivate> selPrivate(do_QueryInterface(selection));
  rv = selPrivate->AddSelectionListener(mSelectionListener);
  if (NS_FAILED(rv))
    return rv;

  // Save old listener so we can unregister it
  nsRefPtr<nsDocViewerFocusListener> oldFocusListener = mFocusListener;

  // focus listener
  //
  // now register ourselves as a focus listener, so that we get called
  // when the focus changes in the window
  nsDocViewerFocusListener *focusListener = new nsDocViewerFocusListener();

  focusListener->Init(this);

  // mFocusListener is a strong reference
  mFocusListener = focusListener;

  if (mDocument) {
    mDocument->AddEventListener(NS_LITERAL_STRING("focus"),
                                mFocusListener,
                                false, false);
    mDocument->AddEventListener(NS_LITERAL_STRING("blur"),
                                mFocusListener,
                                false, false);

    if (oldFocusListener) {
      mDocument->RemoveEventListener(NS_LITERAL_STRING("focus"),
                                     oldFocusListener, false);
      mDocument->RemoveEventListener(NS_LITERAL_STRING("blur"),
                                     oldFocusListener, false);
    }
  }

  if (aDoInitialReflow && mDocument) {
    mDocument->ScrollToRef();
  }

  return NS_OK;
}

static nsPresContext*
CreatePresContext(nsIDocument* aDocument,
                  nsPresContext::nsPresContextType aType,
                  nsView* aContainerView)
{
  if (aContainerView)
    return new nsPresContext(aDocument, aType);
  return new nsRootPresContext(aDocument, aType);
}

//-----------------------------------------------
// This method can be used to initial the "presentation"
// The aDoCreation indicates whether it should create
// all the new objects or just initialize the existing ones
nsresult
nsDocumentViewer::InitInternal(nsIWidget* aParentWidget,
                                 nsISupports *aState,
                                 const nsIntRect& aBounds,
                                 bool aDoCreation,
                                 bool aNeedMakeCX /*= true*/,
                                 bool aForceSetNewDocument /* = true*/)
{
  if (mIsPageMode) {
    // XXXbz should the InitInternal in SetPageMode just pass false
    // here itself?
    aForceSetNewDocument = false;
  }

  // We don't want any scripts to run here. That can cause flushing,
  // which can cause reentry into initialization of this document viewer,
  // which would be disastrous.
  nsAutoScriptBlocker blockScripts;

  mParentWidget = aParentWidget; // not ref counted
  mBounds = aBounds;

  nsresult rv = NS_OK;
  NS_ENSURE_TRUE(mDocument, NS_ERROR_NULL_POINTER);

  nsView* containerView = FindContainerView();

  bool makeCX = false;
  if (aDoCreation) {
    nsresult rv = CreateDeviceContext(containerView);
    NS_ENSURE_SUCCESS(rv, rv);

    // XXXbz this is a nasty hack to do with the fact that we create
    // presentations both in Init() and in Show()...  Ideally we would only do
    // it in one place (Show()) and require that callers call init(), open(),
    // show() in that order or something.
    if (!mPresContext &&
        (aParentWidget || containerView || mDocument->IsBeingUsedAsImage() ||
         (mDocument->GetDisplayDocument() &&
          mDocument->GetDisplayDocument()->GetShell()))) {
      // Create presentation context
      if (mIsPageMode) {
        //Presentation context already created in SetPageMode which is calling this method
      } else {
        mPresContext = CreatePresContext(mDocument,
            nsPresContext::eContext_Galley, containerView);
      }
      NS_ENSURE_TRUE(mPresContext, NS_ERROR_OUT_OF_MEMORY);

      nsresult rv = mPresContext->Init(mDeviceContext); 
      if (NS_FAILED(rv)) {
        mPresContext = nullptr;
        return rv;
      }

#if defined(NS_PRINTING) && defined(NS_PRINT_PREVIEW)
      makeCX = !GetIsPrintPreview() && aNeedMakeCX; // needs to be true except when we are already in PP or we are enabling/disabling paginated mode.
#else
      makeCX = true;
#endif
    }

    if (mPresContext) {
      // Create the ViewManager and Root View...

      // We must do this before we tell the script global object about
      // this new document since doing that will cause us to re-enter
      // into nsSubDocumentFrame code through reflows caused by
      // FlushPendingNotifications() calls down the road...

      rv = MakeWindow(nsSize(mPresContext->DevPixelsToAppUnits(aBounds.width),
                             mPresContext->DevPixelsToAppUnits(aBounds.height)),
                      containerView);
      NS_ENSURE_SUCCESS(rv, rv);
      Hide();

#ifdef NS_PRINT_PREVIEW
      if (mIsPageMode) {
        // I'm leaving this in a broken state for the moment; we should
        // be measuring/scaling with the print device context, not the
        // screen device context, but this is good enough to allow
        // printing reftests to work.
        double pageWidth = 0, pageHeight = 0;
        mPresContext->GetPrintSettings()->GetEffectivePageSize(&pageWidth,
                                                               &pageHeight);
        mPresContext->SetPageSize(
          nsSize(mPresContext->CSSTwipsToAppUnits(NSToIntFloor(pageWidth)),
                 mPresContext->CSSTwipsToAppUnits(NSToIntFloor(pageHeight))));
        mPresContext->SetIsRootPaginatedDocument(true);
        mPresContext->SetPageScale(1.0f);
      }
#endif
    } else {
      // Avoid leaking the old viewer.
      if (mPreviousViewer) {
        mPreviousViewer->Destroy();
        mPreviousViewer = nullptr;
      }
    }
  }

  nsCOMPtr<nsIInterfaceRequestor> requestor(mContainer);
  if (requestor) {
    if (mPresContext) {
      nsCOMPtr<nsILinkHandler> linkHandler;
      requestor->GetInterface(NS_GET_IID(nsILinkHandler),
                              getter_AddRefs(linkHandler));

      mPresContext->SetContainer(mContainer);
      mPresContext->SetLinkHandler(linkHandler);
    }

    // Set script-context-owner in the document

    nsCOMPtr<nsPIDOMWindow> window;
    requestor->GetInterface(NS_GET_IID(nsPIDOMWindow),
                            getter_AddRefs(window));

    if (window) {
      nsCOMPtr<nsIDocument> curDoc = window->GetExtantDoc();
      if (aForceSetNewDocument || curDoc != mDocument) {
        window->SetNewDocument(mDocument, aState, false);
        nsJSContext::LoadStart();
      }
    }
  }

  if (aDoCreation && mPresContext) {
    // The ViewManager and Root View was created above (in
    // MakeWindow())...

    rv = InitPresentationStuff(!makeCX);
  }

  return rv;
}

void nsDocumentViewer::SetNavigationTiming(nsDOMNavigationTiming* timing)
{
  NS_ASSERTION(mDocument, "Must have a document to set navigation timing.");
  if (mDocument) {
    mDocument->SetNavigationTiming(timing);
  }
}

//
// LoadComplete(aStatus)
//
//   aStatus - The status returned from loading the document.
//
// This method is called by the container when the document has been
// completely loaded.
//
NS_IMETHODIMP
nsDocumentViewer::LoadComplete(nsresult aStatus)
{
  /* We need to protect ourself against auto-destruction in case the
     window is closed while processing the OnLoad event.  See bug
     http://bugzilla.mozilla.org/show_bug.cgi?id=78445 for more
     explanation.
  */
  nsRefPtr<nsDocumentViewer> kungFuDeathGrip(this);

  // Flush out layout so it's up-to-date by the time onload is called.
  // Note that this could destroy the window, so do this before
  // checking for our mDocument and its window.
  if (mPresShell && !mStopped) {
    // Hold strong ref because this could conceivably run script
    nsCOMPtr<nsIPresShell> shell = mPresShell;
    shell->FlushPendingNotifications(Flush_Layout);
  }

  nsresult rv = NS_OK;
  NS_ENSURE_TRUE(mDocument, NS_ERROR_NOT_AVAILABLE);

  // First, get the window from the document...
  nsCOMPtr<nsPIDOMWindow> window = mDocument->GetWindow();

  mLoaded = true;

  // Now, fire either an OnLoad or OnError event to the document...
  bool restoring = false;
  // XXXbz imagelib kills off the document load for a full-page image with
  // NS_ERROR_PARSED_DATA_CACHED if it's in the cache.  So we want to treat
  // that one as a success code; otherwise whether we fire onload for the image
  // will depend on whether it's cached!
  if(window &&
     (NS_SUCCEEDED(aStatus) || aStatus == NS_ERROR_PARSED_DATA_CACHED)) {
    nsEventStatus status = nsEventStatus_eIgnore;
    WidgetEvent event(true, NS_LOAD);
    event.mFlags.mBubbles = false;
     // XXX Dispatching to |window|, but using |document| as the target.
    event.target = mDocument;

    // If the document presentation is being restored, we don't want to fire
    // onload to the document content since that would likely confuse scripts
    // on the page.

    nsIDocShell *docShell = window->GetDocShell();
    NS_ENSURE_TRUE(docShell, NS_ERROR_UNEXPECTED);

    docShell->GetRestoringDocument(&restoring);
    if (!restoring) {
      NS_ASSERTION(mDocument->IsXUL() || // readyState for XUL is bogus
                   mDocument->GetReadyStateEnum() ==
                     nsIDocument::READYSTATE_INTERACTIVE ||
                   // test_stricttransportsecurity.html has old-style
                   // docshell-generated about:blank docs reach this code!
                   (mDocument->GetReadyStateEnum() ==
                      nsIDocument::READYSTATE_UNINITIALIZED &&
                    NS_IsAboutBlank(mDocument->GetDocumentURI())),
                   "Bad readystate");
      nsCOMPtr<nsIDocument> d = mDocument;
      mDocument->SetReadyStateInternal(nsIDocument::READYSTATE_COMPLETE);

      nsRefPtr<nsDOMNavigationTiming> timing(d->GetNavigationTiming());
      if (timing) {
        timing->NotifyLoadEventStart();
      }

      // Dispatch observer notification to notify observers document load is complete.
      nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
      nsIPrincipal *principal = d->NodePrincipal();
      os->NotifyObservers(d,
                          nsContentUtils::IsSystemPrincipal(principal) ?
                          "chrome-document-loaded" :
                          "content-document-loaded",
                          nullptr);

      EventDispatcher::Dispatch(window, mPresContext, &event, nullptr, &status);
      if (timing) {
        timing->NotifyLoadEventEnd();
      }
    }
  } else {
    // XXX: Should fire error event to the document...
  }

  // Notify the document that it has been shown (regardless of whether
  // it was just loaded). Note: mDocument may be null now if the above
  // firing of onload caused the document to unload.
  if (mDocument) {
    // Re-get window, since it might have changed during above firing of onload
    window = mDocument->GetWindow();
    if (window) {
      nsIDocShell *docShell = window->GetDocShell();
      bool isInUnload;
      if (docShell && NS_SUCCEEDED(docShell->GetIsInUnload(&isInUnload)) &&
          !isInUnload) {
        mDocument->OnPageShow(restoring, nullptr);
      }
    }
  }

  if (!mStopped) {
    if (mDocument) {
      mDocument->ScrollToRef();
    }

    // Now that the document has loaded, we can tell the presshell
    // to unsuppress painting.
    if (mPresShell) {
      nsCOMPtr<nsIPresShell> shellDeathGrip(mPresShell);
      mPresShell->UnsuppressPainting();
      // mPresShell could have been removed now, see bug 378682/421432
      if (mPresShell) {
        mPresShell->LoadComplete();
      }
    }
  }

  nsJSContext::LoadEnd();

#ifdef NS_PRINTING
  // Check to see if someone tried to print during the load
  if (mPrintIsPending) {
    mPrintIsPending        = false;
    mPrintDocIsFullyLoaded = true;
    Print(mCachedPrintSettings, mCachedPrintWebProgressListner);
    mCachedPrintSettings           = nullptr;
    mCachedPrintWebProgressListner = nullptr;
  }
#endif

  return rv;
}

NS_IMETHODIMP
nsDocumentViewer::PermitUnload(bool aCallerClosesWindow,
                               bool *aPermitUnload)
{
  bool shouldPrompt = true;
  return PermitUnloadInternal(aCallerClosesWindow, &shouldPrompt,
                              aPermitUnload);
}


nsresult
nsDocumentViewer::PermitUnloadInternal(bool aCallerClosesWindow,
                                       bool *aShouldPrompt,
                                       bool *aPermitUnload)
{
  AutoDontWarnAboutSyncXHR disableSyncXHRWarning;

  *aPermitUnload = true;

  if (!mDocument
   || mInPermitUnload
   || mCallerIsClosingWindow
   || mInPermitUnloadPrompt) {
    return NS_OK;
  }

  static bool sIsBeforeUnloadDisabled;
  static bool sBeforeUnloadPrefCached = false;

  if (!sBeforeUnloadPrefCached ) {
    sBeforeUnloadPrefCached = true;
    Preferences::AddBoolVarCache(&sIsBeforeUnloadDisabled,
                                 BEFOREUNLOAD_DISABLED_PREFNAME);
  }

  // If the user has turned off onbeforeunload warnings, no need to check.
  if (sIsBeforeUnloadDisabled) {
    return NS_OK;
  }

  // First, get the script global object from the document...
  nsPIDOMWindow *window = mDocument->GetWindow();

  if (!window) {
    // This is odd, but not fatal
    NS_WARNING("window not set for document!");
    return NS_OK;
  }

  NS_ASSERTION(nsContentUtils::IsSafeToRunScript(), "This is unsafe");

  // Now, fire an BeforeUnload event to the document and see if it's ok
  // to unload...
  nsCOMPtr<nsIDOMDocument> domDoc = do_QueryInterface(mDocument);
  nsCOMPtr<nsIDOMEvent> event;
  domDoc->CreateEvent(NS_LITERAL_STRING("beforeunloadevent"),
                      getter_AddRefs(event));
  nsCOMPtr<nsIDOMBeforeUnloadEvent> beforeUnload = do_QueryInterface(event);
  NS_ENSURE_STATE(beforeUnload);
  nsresult rv = event->InitEvent(NS_LITERAL_STRING("beforeunload"),
                                 false, true);
  NS_ENSURE_SUCCESS(rv, rv);

  // Dispatching to |window|, but using |document| as the target.
  event->SetTarget(mDocument);
  event->SetTrusted(true);

  // In evil cases we might be destroyed while handling the
  // onbeforeunload event, don't let that happen. (see also bug#331040)
  nsRefPtr<nsDocumentViewer> kungFuDeathGrip(this);

  {
    // Never permit popups from the beforeunload handler, no matter
    // how we get here.
    nsAutoPopupStatePusher popupStatePusher(openAbused, true);

    // Never permit dialogs from the beforeunload handler
    nsCOMPtr<nsIDOMWindowUtils> utils = do_GetInterface(window);
    bool dialogsWereEnabled = false;
    utils->AreDialogsEnabled(&dialogsWereEnabled);
    utils->DisableDialogs();

    mInPermitUnload = true;
    EventDispatcher::DispatchDOMEvent(window, nullptr, event, mPresContext,
                                      nullptr);
    mInPermitUnload = false;
    if (dialogsWereEnabled) {
      utils->EnableDialogs();
    }
  }

  nsCOMPtr<nsIDocShell> docShell(mContainer);
  nsAutoString text;
  beforeUnload->GetReturnValue(text);
  if (*aShouldPrompt && (event->GetInternalNSEvent()->mFlags.mDefaultPrevented ||
                         !text.IsEmpty())) {
    // Ask the user if it's ok to unload the current page

    nsCOMPtr<nsIPrompt> prompt = do_GetInterface(docShell);

    if (prompt) {
      nsCOMPtr<nsIWritablePropertyBag2> promptBag = do_QueryInterface(prompt);
      if (promptBag) {
        bool isTabModalPromptAllowed;
        GetIsTabModalPromptAllowed(&isTabModalPromptAllowed);
        promptBag->SetPropertyAsBool(NS_LITERAL_STRING("allowTabModal"),
                                     isTabModalPromptAllowed);
      }

      nsXPIDLString title, message, stayLabel, leaveLabel;
      rv  = nsContentUtils::GetLocalizedString(nsContentUtils::eDOM_PROPERTIES,
                                               "OnBeforeUnloadTitle",
                                               title);
      nsresult tmp = nsContentUtils::GetLocalizedString(nsContentUtils::eDOM_PROPERTIES,
                                               "OnBeforeUnloadMessage",
                                               message);
      if (NS_FAILED(tmp)) {
        rv = tmp;
      }
      tmp = nsContentUtils::GetLocalizedString(nsContentUtils::eDOM_PROPERTIES,
                                               "OnBeforeUnloadLeaveButton",
                                               leaveLabel);
      if (NS_FAILED(tmp)) {
        rv = tmp;
      }
      tmp = nsContentUtils::GetLocalizedString(nsContentUtils::eDOM_PROPERTIES,
                                               "OnBeforeUnloadStayButton",
                                               stayLabel);
      if (NS_FAILED(tmp)) {
        rv = tmp;
      }

      if (NS_FAILED(rv) || !title || !message || !stayLabel || !leaveLabel) {
        NS_ERROR("Failed to get strings from dom.properties!");
        return NS_OK;
      }

      // Although the exact value is ignored, we must not pass invalid
      // bool values through XPConnect.
      bool dummy = false;
      int32_t buttonPressed = 0;
      uint32_t buttonFlags = (nsIPrompt::BUTTON_POS_0_DEFAULT |
                             (nsIPrompt::BUTTON_TITLE_IS_STRING * nsIPrompt::BUTTON_POS_0) |
                             (nsIPrompt::BUTTON_TITLE_IS_STRING * nsIPrompt::BUTTON_POS_1));

      nsAutoSyncOperation sync(mDocument);
      mInPermitUnloadPrompt = true;
      rv = prompt->ConfirmEx(title, message, buttonFlags,
                             leaveLabel, stayLabel, nullptr, nullptr,
                             &dummy, &buttonPressed);
      mInPermitUnloadPrompt = false;

      // If the prompt aborted, we tell our consumer that it is not allowed
      // to unload the page. One reason that prompts abort is that the user
      // performed some action that caused the page to unload while our prompt
      // was active. In those cases we don't want our consumer to also unload
      // the page.
      //
      // XXX: Are there other cases where prompts can abort? Is it ok to
      //      prevent unloading the page in those cases?
      if (NS_FAILED(rv)) {
        *aPermitUnload = false;
        return NS_OK;
      }

      // Button 0 == leave, button 1 == stay
      *aPermitUnload = (buttonPressed == 0);
      // If the user decided to go ahead, make sure not to prompt the user again
      // by toggling the internal prompting bool to false:
      if (*aPermitUnload) {
        *aShouldPrompt = false;
      }
    }
  }

  if (docShell) {
    int32_t childCount;
    docShell->GetChildCount(&childCount);

    for (int32_t i = 0; i < childCount && *aPermitUnload; ++i) {
      nsCOMPtr<nsIDocShellTreeItem> item;
      docShell->GetChildAt(i, getter_AddRefs(item));

      nsCOMPtr<nsIDocShell> docShell(do_QueryInterface(item));

      if (docShell) {
        nsCOMPtr<nsIContentViewer> cv;
        docShell->GetContentViewer(getter_AddRefs(cv));

        if (cv) {
          cv->PermitUnloadInternal(aCallerClosesWindow, aShouldPrompt,
                                   aPermitUnload);
        }
      }
    }
  }

  if (aCallerClosesWindow && *aPermitUnload)
    mCallerIsClosingWindow = true;

  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::GetBeforeUnloadFiring(bool* aInEvent)
{
  *aInEvent = mInPermitUnload;
  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::GetInPermitUnload(bool* aInEvent)
{
  *aInEvent = mInPermitUnloadPrompt;
  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::ResetCloseWindow()
{
  mCallerIsClosingWindow = false;

  nsCOMPtr<nsIDocShell> docShell(mContainer);
  if (docShell) {
    int32_t childCount;
    docShell->GetChildCount(&childCount);

    for (int32_t i = 0; i < childCount; ++i) {
      nsCOMPtr<nsIDocShellTreeItem> item;
      docShell->GetChildAt(i, getter_AddRefs(item));

      nsCOMPtr<nsIDocShell> docShell(do_QueryInterface(item));

      if (docShell) {
        nsCOMPtr<nsIContentViewer> cv;
        docShell->GetContentViewer(getter_AddRefs(cv));

        if (cv) {
          cv->ResetCloseWindow();
        }
      }
    }
  }
  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::PageHide(bool aIsUnload)
{
  AutoDontWarnAboutSyncXHR disableSyncXHRWarning;

  mHidden = true;

  if (!mDocument) {
    return NS_ERROR_NULL_POINTER;
  }

  mDocument->OnPageHide(!aIsUnload, nullptr);

  // inform the window so that the focus state is reset.
  NS_ENSURE_STATE(mDocument);
  nsPIDOMWindow *window = mDocument->GetWindow();
  if (window)
    window->PageHidden();

  if (aIsUnload) {
    // Poke the GC. The window might be collectable garbage now.
    nsJSContext::PokeGC(JS::gcreason::PAGE_HIDE, NS_GC_DELAY * 2);

    // if Destroy() was called during OnPageHide(), mDocument is nullptr.
    NS_ENSURE_STATE(mDocument);

    // First, get the window from the document...
    nsPIDOMWindow *window = mDocument->GetWindow();

    if (!window) {
      // Fail if no window is available...
      NS_WARNING("window not set for document!");
      return NS_ERROR_NULL_POINTER;
    }

    // Now, fire an Unload event to the document...
    nsEventStatus status = nsEventStatus_eIgnore;
    WidgetEvent event(true, NS_PAGE_UNLOAD);
    event.mFlags.mBubbles = false;
    // XXX Dispatching to |window|, but using |document| as the target.
    event.target = mDocument;

    // Never permit popups from the unload handler, no matter how we get
    // here.
    nsAutoPopupStatePusher popupStatePusher(openAbused, true);

    EventDispatcher::Dispatch(window, mPresContext, &event, nullptr, &status);
  }

#ifdef MOZ_XUL
  // look for open menupopups and close them after the unload event, in case
  // the unload event listeners open any new popups
  nsContentUtils::HidePopupsInDocument(mDocument);
#endif

  return NS_OK;
}

static void
AttachContainerRecurse(nsIDocShell* aShell)
{
  nsCOMPtr<nsIContentViewer> viewer;
  aShell->GetContentViewer(getter_AddRefs(viewer));
  if (viewer) {
    nsIDocument* doc = viewer->GetDocument();
    if (doc) {
      doc->SetContainer(static_cast<nsDocShell*>(aShell));
    }
    nsRefPtr<nsPresContext> pc;
    viewer->GetPresContext(getter_AddRefs(pc));
    if (pc) {
      pc->SetContainer(static_cast<nsDocShell*>(aShell));
      pc->SetLinkHandler(nsCOMPtr<nsILinkHandler>(do_QueryInterface(aShell)));
    }
    nsCOMPtr<nsIPresShell> presShell;
    viewer->GetPresShell(getter_AddRefs(presShell));
    if (presShell) {
      presShell->SetForwardingContainer(WeakPtr<nsDocShell>());
    }
  }

  // Now recurse through the children
  int32_t childCount;
  aShell->GetChildCount(&childCount);
  for (int32_t i = 0; i < childCount; ++i) {
    nsCOMPtr<nsIDocShellTreeItem> childItem;
    aShell->GetChildAt(i, getter_AddRefs(childItem));
    AttachContainerRecurse(nsCOMPtr<nsIDocShell>(do_QueryInterface(childItem)));
  }
}

NS_IMETHODIMP
nsDocumentViewer::Open(nsISupports *aState, nsISHEntry *aSHEntry)
{
  NS_ENSURE_TRUE(mPresShell, NS_ERROR_NOT_INITIALIZED);

  if (mDocument)
    mDocument->SetContainer(mContainer);

  nsresult rv = InitInternal(mParentWidget, aState, mBounds, false);
  NS_ENSURE_SUCCESS(rv, rv);

  mHidden = false;

  if (mPresShell)
    mPresShell->SetForwardingContainer(WeakPtr<nsDocShell>());

  // Rehook the child presentations.  The child shells are still in
  // session history, so get them from there.

  if (aSHEntry) {
    nsCOMPtr<nsIDocShellTreeItem> item;
    int32_t itemIndex = 0;
    while (NS_SUCCEEDED(aSHEntry->ChildShellAt(itemIndex++,
                                               getter_AddRefs(item))) && item) {
      AttachContainerRecurse(nsCOMPtr<nsIDocShell>(do_QueryInterface(item)));
    }
  }
  
  SyncParentSubDocMap();

  if (mFocusListener && mDocument) {
    mDocument->AddEventListener(NS_LITERAL_STRING("focus"), mFocusListener,
                                false, false);
    mDocument->AddEventListener(NS_LITERAL_STRING("blur"), mFocusListener,
                                false, false);
  }

  // XXX re-enable image animations once that works correctly

  PrepareToStartLoad();

  // When loading a page from the bfcache with puppet widgets, we do the
  // widget attachment here (it is otherwise done in MakeWindow, which is
  // called for non-bfcache pages in the history, but not bfcache pages).
  // Attachment is necessary, since we get detached when another page
  // is browsed to. That is, if we are one page A, then when we go to
  // page B, we detach. So page A's view has no widget. If we then go
  // back to it, and it is in the bfcache, we will use that view, which
  // doesn't have a widget. The attach call here will properly attach us.
  if (nsIWidget::UsePuppetWidgets() && mPresContext &&
      ShouldAttachToTopLevel()) {
    // If the old view is already attached to our parent, detach
    DetachFromTopLevelWidget();

    nsViewManager *vm = GetViewManager();
    NS_ABORT_IF_FALSE(vm, "no view manager");
    nsView* v = vm->GetRootView();
    NS_ABORT_IF_FALSE(v, "no root view");
    NS_ABORT_IF_FALSE(mParentWidget, "no mParentWidget to set");
    v->AttachToTopLevelWidget(mParentWidget);

    mAttachedToParent = true;
  }

  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::Close(nsISHEntry *aSHEntry)
{
  // All callers are supposed to call close to break circular
  // references.  If we do this stuff in the destructor, the
  // destructor might never be called (especially if we're being
  // used from JS.

  mSHEntry = aSHEntry;

  // Close is also needed to disable scripts during paint suppression,
  // since we transfer the existing global object to the new document
  // that is loaded.  In the future, the global object may become a proxy
  // for an object that can be switched in and out so that we don't need
  // to disable scripts during paint suppression.

  if (!mDocument)
    return NS_OK;

#if defined(NS_PRINTING) && defined(NS_PRINT_PREVIEW)
  // Turn scripting back on
  // after PrintPreview had turned it off
  if (GetIsPrintPreview() && mPrintEngine) {
    mPrintEngine->TurnScriptingOn(true);
  }
#endif

#ifdef NS_PRINTING
  // A Close was called while we were printing
  // so don't clear the ScriptGlobalObject
  // or clear the mDocument below
  if (mPrintEngine && !mClosingWhilePrinting) {
    mClosingWhilePrinting = true;
  } else
#endif
    {
      // out of band cleanup of docshell
      mDocument->SetScriptGlobalObject(nullptr);

      if (!mSHEntry && mDocument)
        mDocument->RemovedFromDocShell();
    }

  if (mFocusListener && mDocument) {
    mDocument->RemoveEventListener(NS_LITERAL_STRING("focus"), mFocusListener,
                                   false);
    mDocument->RemoveEventListener(NS_LITERAL_STRING("blur"), mFocusListener,
                                   false);
  }

  return NS_OK;
}

static void
DetachContainerRecurse(nsIDocShell *aShell)
{
  // Unhook this docshell's presentation
  nsCOMPtr<nsIContentViewer> viewer;
  aShell->GetContentViewer(getter_AddRefs(viewer));
  if (viewer) {
    nsIDocument* doc = viewer->GetDocument();
    if (doc) {
      doc->SetContainer(nullptr);
    }
    nsRefPtr<nsPresContext> pc;
    viewer->GetPresContext(getter_AddRefs(pc));
    if (pc) {
      pc->Detach();
    }
    nsCOMPtr<nsIPresShell> presShell;
    viewer->GetPresShell(getter_AddRefs(presShell));
    if (presShell) {
      auto weakShell = static_cast<nsDocShell*>(aShell)->asWeakPtr();
      presShell->SetForwardingContainer(weakShell);
    }
  }

  // Now recurse through the children
  int32_t childCount;
  aShell->GetChildCount(&childCount);
  for (int32_t i = 0; i < childCount; ++i) {
    nsCOMPtr<nsIDocShellTreeItem> childItem;
    aShell->GetChildAt(i, getter_AddRefs(childItem));
    DetachContainerRecurse(nsCOMPtr<nsIDocShell>(do_QueryInterface(childItem)));
  }
}

NS_IMETHODIMP
nsDocumentViewer::Destroy()
{
  NS_ASSERTION(mDocument, "No document in Destroy()!");

#ifdef NS_PRINTING
  // Here is where we check to see if the document was still being prepared 
  // for printing when it was asked to be destroy from someone externally
  // This usually happens if the document is unloaded while the user is in the
  // Print Dialog
  //
  // So we flip the bool to remember that the document is going away
  // and we can clean up and abort later after returning from the Print Dialog
  if (mPrintEngine) {
    if (mPrintEngine->CheckBeforeDestroy()) {
      return NS_OK;
    }
  }
  mBeforeAndAfterPrint = nullptr;
#endif

  // Don't let the document get unloaded while we are printing.
  // this could happen if we hit the back button during printing.
  // We also keep the viewer from being cached in session history, since
  // we require all documents there to be sanitized.
  if (mDestroyRefCount != 0) {
    --mDestroyRefCount;
    return NS_OK;
  }

  // If we were told to put ourselves into session history instead of destroy
  // the presentation, do that now.
  if (mSHEntry) {
    if (mPresShell)
      mPresShell->Freeze();

    // Make sure the presentation isn't torn down by Hide().
    mSHEntry->SetSticky(mIsSticky);
    mIsSticky = true;

    bool savePresentation = mDocument ? mDocument->IsBFCachingAllowed() : true;

    // Remove our root view from the view hierarchy.
    if (mPresShell) {
      nsViewManager *vm = mPresShell->GetViewManager();
      if (vm) {
        nsView *rootView = vm->GetRootView();

        if (rootView) {
          nsView *rootViewParent = rootView->GetParent();
          if (rootViewParent) {
            nsViewManager *parentVM = rootViewParent->GetViewManager();
            if (parentVM) {
              parentVM->RemoveChild(rootView);
            }
          }
        }
      }
    }

    Hide();

    // This is after Hide() so that the user doesn't see the inputs clear.
    if (mDocument) {
      mDocument->Sanitize();
    }

    // Reverse ownership. Do this *after* calling sanitize so that sanitize
    // doesn't cause mutations that make the SHEntry drop the presentation

    // Grab a reference to mSHEntry before calling into things like
    // SyncPresentationState that might mess with our members.
    nsCOMPtr<nsISHEntry> shEntry = mSHEntry; // we'll need this below
    mSHEntry = nullptr;

    if (savePresentation) {
      shEntry->SetContentViewer(this);
    }

    // Always sync the presentation state.  That way even if someone screws up
    // and shEntry has no window state at this point we'll be ok; we just won't
    // cache ourselves.
    shEntry->SyncPresentationState();

    // Shut down accessibility for the document before we start to tear it down.
#ifdef ACCESSIBILITY
    if (mPresShell) {
      a11y::DocAccessible* docAcc = mPresShell->GetDocAccessible();
      if (docAcc) {
        docAcc->Shutdown();
      }
    }
#endif

    // Break the link from the document/presentation to the docshell, so that
    // link traversals cannot affect the currently-loaded document.
    // When the presentation is restored, Open() and InitInternal() will reset
    // these pointers to their original values.

    if (mDocument) {
      mDocument->SetContainer(nullptr);
    }
    if (mPresContext) {
      mPresContext->Detach();
    }
    if (mPresShell) {
      mPresShell->SetForwardingContainer(mContainer);
    }

    // Do the same for our children.  Note that we need to get the child
    // docshells from the SHEntry now; the docshell will have cleared them.
    nsCOMPtr<nsIDocShellTreeItem> item;
    int32_t itemIndex = 0;
    while (NS_SUCCEEDED(shEntry->ChildShellAt(itemIndex++,
                                              getter_AddRefs(item))) && item) {
      DetachContainerRecurse(nsCOMPtr<nsIDocShell>(do_QueryInterface(item)));
    }

    return NS_OK;
  }

  // The document was not put in the bfcache

  if (mPresShell) {
    DestroyPresShell();
  }
  if (mDocument) {
    mDocument->Destroy();
    mDocument = nullptr;
  }

  // All callers are supposed to call destroy to break circular
  // references.  If we do this stuff in the destructor, the
  // destructor might never be called (especially if we're being
  // used from JS.

#ifdef NS_PRINTING
  if (mPrintEngine) {
#ifdef NS_PRINT_PREVIEW
    bool doingPrintPreview;
    mPrintEngine->GetDoingPrintPreview(&doingPrintPreview);
    if (doingPrintPreview) {
      mPrintEngine->FinishPrintPreview();
    }
#endif

    mPrintEngine->Destroy();
    mPrintEngine = nullptr;
  }
#endif

  // Avoid leaking the old viewer.
  if (mPreviousViewer) {
    mPreviousViewer->Destroy();
    mPreviousViewer = nullptr;
  }

  mDeviceContext = nullptr;

  if (mPresContext) {
    DestroyPresContext();
  }

  mWindow = nullptr;
  mViewManager = nullptr;
  mContainer = WeakPtr<nsDocShell>();

  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::Stop(void)
{
  NS_ASSERTION(mDocument, "Stop called too early or too late");
  if (mDocument) {
    mDocument->StopDocumentLoad();
  }

  if (!mHidden && (mLoaded || mStopped) && mPresContext && !mSHEntry)
    mPresContext->SetImageAnimationMode(imgIContainer::kDontAnimMode);

  mStopped = true;

  if (!mLoaded && mPresShell) {
    // Well, we might as well paint what we have so far.
    nsCOMPtr<nsIPresShell> shellDeathGrip(mPresShell); // bug 378682
    mPresShell->UnsuppressPainting();
  }

  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::GetDOMDocument(nsIDOMDocument **aResult)
{
  NS_ENSURE_TRUE(mDocument, NS_ERROR_NOT_AVAILABLE);
  return CallQueryInterface(mDocument, aResult);
}

NS_IMETHODIMP_(nsIDocument *)
nsDocumentViewer::GetDocument()
{
  return mDocument;
}

NS_IMETHODIMP
nsDocumentViewer::SetDOMDocument(nsIDOMDocument *aDocument)
{
  // Assumptions:
  //
  // 1) this document viewer has been initialized with a call to Init().
  // 2) the stylesheets associated with the document have been added
  // to the document.

  // XXX Right now, this method assumes that the layout of the current
  // document hasn't started yet.  More cleanup will probably be
  // necessary to make this method work for the case when layout *has*
  // occurred for the current document.
  // That work can happen when and if it is needed.

  if (!aDocument)
    return NS_ERROR_NULL_POINTER;

  nsCOMPtr<nsIDocument> newDoc = do_QueryInterface(aDocument);
  NS_ENSURE_TRUE(newDoc, NS_ERROR_UNEXPECTED);

  return SetDocumentInternal(newDoc, false);
}

NS_IMETHODIMP
nsDocumentViewer::SetDocumentInternal(nsIDocument* aDocument,
                                        bool aForceReuseInnerWindow)
{
  MOZ_ASSERT(aDocument);

  // Set new container
  aDocument->SetContainer(mContainer);

  if (mDocument != aDocument) {
    if (mDocument->IsStaticDocument()) {
      mDocument->SetScriptGlobalObject(nullptr);
      mDocument->Destroy();
    }
    // Replace the old document with the new one. Do this only when
    // the new document really is a new document.
    mDocument = aDocument;

    // Set the script global object on the new document
    nsCOMPtr<nsPIDOMWindow> window =
      do_GetInterface(static_cast<nsIDocShell*>(mContainer.get()));
    if (window) {
      window->SetNewDocument(aDocument, nullptr, aForceReuseInnerWindow);
    }

    // Clear the list of old child docshells. Child docshells for the new
    // document will be constructed as frames are created.
    if (!aDocument->IsStaticDocument()) {
      nsCOMPtr<nsIDocShell> node(mContainer);
      if (node) {
        int32_t count;
        node->GetChildCount(&count);
        for (int32_t i = 0; i < count; ++i) {
          nsCOMPtr<nsIDocShellTreeItem> child;
          node->GetChildAt(0, getter_AddRefs(child));
          node->RemoveChild(child);
        }
      }
    }
  }

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

  // Replace the current pres shell with a new shell for the new document

  if (mPresShell) {
    DestroyPresShell();
  }

  if (mPresContext) {
    DestroyPresContext();

    mWindow = nullptr;
    InitInternal(mParentWidget, nullptr, mBounds, true, true, false);
  }

  return rv;
}

nsIPresShell*
nsDocumentViewer::GetPresShell()
{
  return mPresShell;
}

nsPresContext*
nsDocumentViewer::GetPresContext()
{
  return mPresContext;
}

nsViewManager*
nsDocumentViewer::GetViewManager()
{
  return mViewManager;
}

NS_IMETHODIMP
nsDocumentViewer::GetPresShell(nsIPresShell** aResult)
{
  nsIPresShell* shell = GetPresShell();
  NS_IF_ADDREF(*aResult = shell);
  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::GetPresContext(nsPresContext** aResult)
{
  nsPresContext* pc = GetPresContext();
  NS_IF_ADDREF(*aResult = pc);
  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::GetBounds(nsIntRect& aResult)
{
  NS_ENSURE_TRUE(mDocument, NS_ERROR_NOT_AVAILABLE);
  aResult = mBounds;
  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::GetPreviousViewer(nsIContentViewer** aViewer)
{
  *aViewer = mPreviousViewer;
  NS_IF_ADDREF(*aViewer);
  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::SetPreviousViewer(nsIContentViewer* aViewer)
{
  // NOTE:  |Show| sets |mPreviousViewer| to null without calling this
  // function.

  if (aViewer) {
    NS_ASSERTION(!mPreviousViewer,
                 "can't set previous viewer when there already is one");

    // In a multiple chaining situation (which occurs when running a thrashing
    // test like i-bench or jrgm's tests with no delay), we can build up a
    // whole chain of viewers.  In order to avoid this, we always set our previous
    // viewer to the MOST previous viewer in the chain, and then dump the intermediate
    // link from the chain.  This ensures that at most only 2 documents are alive
    // and undestroyed at any given time (the one that is showing and the one that
    // is loading with painting suppressed).
    // It's very important that if this ever gets changed the code
    // before the RestorePresentation call in nsDocShell::InternalLoad
    // be changed accordingly.
    nsCOMPtr<nsIContentViewer> prevViewer;
    aViewer->GetPreviousViewer(getter_AddRefs(prevViewer));
    if (prevViewer) {
      aViewer->SetPreviousViewer(nullptr);
      aViewer->Destroy();
      return SetPreviousViewer(prevViewer);
    }
  }

  mPreviousViewer = aViewer;
  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::SetBounds(const nsIntRect& aBounds)
{
  NS_ENSURE_TRUE(mDocument, NS_ERROR_NOT_AVAILABLE);

  mBounds = aBounds;
  if (mWindow) {
    if (!mAttachedToParent) {
      // Don't have the widget repaint. Layout will generate repaint requests
      // during reflow.
      mWindow->Resize(aBounds.x, aBounds.y,
                      aBounds.width, aBounds.height,
                      false);
    }
  } else if (mPresContext && mViewManager) {
    int32_t p2a = mPresContext->AppUnitsPerDevPixel();
    mViewManager->SetWindowDimensions(NSIntPixelsToAppUnits(mBounds.width, p2a),
                                      NSIntPixelsToAppUnits(mBounds.height, p2a));
  }

  // If there's a previous viewer, it's the one that's actually showing,
  // so be sure to resize it as well so it paints over the right area.
  // This may slow down the performance of the new page load, but resize
  // during load is also probably a relatively unusual condition
  // relating to things being hidden while something is loaded.  It so
  // happens that Firefox does this a good bit with its infobar, and it
  // looks ugly if we don't do this.
  if (mPreviousViewer) {
    nsCOMPtr<nsIContentViewer> previousViewer = mPreviousViewer;
    previousViewer->SetBounds(aBounds);
  }

  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::Move(int32_t aX, int32_t aY)
{
  NS_ENSURE_TRUE(mDocument, NS_ERROR_NOT_AVAILABLE);
  mBounds.MoveTo(aX, aY);
  if (mWindow) {
    mWindow->Move(aX, aY);
  }
  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::Show(void)
{
  NS_ENSURE_TRUE(mDocument, NS_ERROR_NOT_AVAILABLE);

  // We don't need the previous viewer anymore since we're not
  // displaying it.
  if (mPreviousViewer) {
    // This little dance *may* only be to keep
    // PresShell::EndObservingDocument happy, but I'm not sure.
    nsCOMPtr<nsIContentViewer> prevViewer(mPreviousViewer);
    mPreviousViewer = nullptr;
    prevViewer->Destroy();

    // Make sure we don't have too many cached ContentViewers
    nsCOMPtr<nsIDocShellTreeItem> treeItem(mContainer);
    if (treeItem) {
      // We need to find the root DocShell since only that object has an
      // SHistory and we need the SHistory to evict content viewers
      nsCOMPtr<nsIDocShellTreeItem> root;
      treeItem->GetSameTypeRootTreeItem(getter_AddRefs(root));
      nsCOMPtr<nsIWebNavigation> webNav = do_QueryInterface(root);
      nsCOMPtr<nsISHistory> history;
      webNav->GetSessionHistory(getter_AddRefs(history));
      nsCOMPtr<nsISHistoryInternal> historyInt = do_QueryInterface(history);
      if (historyInt) {
        int32_t prevIndex,loadedIndex;
        nsCOMPtr<nsIDocShell> docShell = do_QueryInterface(treeItem);
        docShell->GetPreviousTransIndex(&prevIndex);
        docShell->GetLoadedTransIndex(&loadedIndex);
#ifdef DEBUG_PAGE_CACHE
        printf("About to evict content viewers: prev=%d, loaded=%d\n",
               prevIndex, loadedIndex);
#endif
        historyInt->EvictOutOfRangeContentViewers(loadedIndex);
      }
    }
  }

  if (mWindow) {
    // When attached to a top level xul window, we do not need to call
    // Show on the widget. Underlying window management code handles
    // this when the window is initialized.
    if (!mAttachedToParent) {
      mWindow->Show(true);
    }
  }

  if (mDocument && !mPresShell) {
    NS_ASSERTION(!mWindow, "Window already created but no presshell?");

    nsCOMPtr<nsIBaseWindow> base_win(mContainer);
    if (base_win) {
      base_win->GetParentWidget(&mParentWidget);
      if (mParentWidget) {
        mParentWidget->Release(); // GetParentWidget AddRefs, but mParentWidget is weak
      }
    }

    nsView* containerView = FindContainerView();

    nsresult rv = CreateDeviceContext(containerView);
    NS_ENSURE_SUCCESS(rv, rv);

    // Create presentation context
    NS_ASSERTION(!mPresContext, "Shouldn't have a prescontext if we have no shell!");
    mPresContext = CreatePresContext(mDocument,
        nsPresContext::eContext_Galley, containerView);
    NS_ENSURE_TRUE(mPresContext, NS_ERROR_OUT_OF_MEMORY);

    rv = mPresContext->Init(mDeviceContext);
    if (NS_FAILED(rv)) {
      mPresContext = nullptr;
      return rv;
    }

    rv = MakeWindow(nsSize(mPresContext->DevPixelsToAppUnits(mBounds.width),
                           mPresContext->DevPixelsToAppUnits(mBounds.height)),
                           containerView);
    if (NS_FAILED(rv))
      return rv;

    if (mPresContext && base_win) {
      nsCOMPtr<nsILinkHandler> linkHandler(do_GetInterface(base_win));

      if (linkHandler) {
        mPresContext->SetLinkHandler(linkHandler);
      }

      mPresContext->SetContainer(mContainer);
    }

    if (mPresContext) {
      Hide();

      rv = InitPresentationStuff(mDocument->MayStartLayout());
    }

    // If we get here the document load has already started and the
    // window is shown because some JS on the page caused it to be
    // shown...

    if (mPresShell) {
      nsCOMPtr<nsIPresShell> shellDeathGrip(mPresShell); // bug 378682
      mPresShell->UnsuppressPainting();
    }
  }

  // Notify observers that a new page has been shown. This will get run
  // from the event loop after we actually draw the page.
  NS_DispatchToMainThread(new nsDocumentShownDispatcher(mDocument));

  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::Hide(void)
{
  if (!mAttachedToParent && mWindow) {
    mWindow->Show(false);
  }

  if (!mPresShell)
    return NS_OK;

  NS_ASSERTION(mPresContext, "Can't have a presshell and no prescontext!");

  // Avoid leaking the old viewer.
  if (mPreviousViewer) {
    mPreviousViewer->Destroy();
    mPreviousViewer = nullptr;
  }

  if (mIsSticky) {
    // This window is sticky, that means that it might be shown again
    // and we don't want the presshell n' all that to be thrown away
    // just because the window is hidden.

    return NS_OK;
  }

  nsCOMPtr<nsIDocShell> docShell(mContainer);
  if (docShell) {
    nsCOMPtr<nsILayoutHistoryState> layoutState;
    mPresShell->CaptureHistoryState(getter_AddRefs(layoutState));
  }

  DestroyPresShell();

  DestroyPresContext();

  mViewManager   = nullptr;
  mWindow        = nullptr;
  mDeviceContext = nullptr;
  mParentWidget  = nullptr;

  nsCOMPtr<nsIBaseWindow> base_win(mContainer);

  if (base_win && !mAttachedToParent) {
    base_win->SetParentWidget(nullptr);
  }

  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::GetSticky(bool *aSticky)
{
  *aSticky = mIsSticky;

  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::SetSticky(bool aSticky)
{
  mIsSticky = aSticky;

  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::RequestWindowClose(bool* aCanClose)
{
#ifdef NS_PRINTING
  if (mPrintIsPending || (mPrintEngine && mPrintEngine->GetIsPrinting())) {
    *aCanClose = false;
    mDeferredWindowClose = true;
  } else
#endif
    *aCanClose = true;

  return NS_OK;
}

static bool
AppendAgentSheet(nsIStyleSheet *aSheet, void *aData)
{
  nsStyleSet *styleSet = static_cast<nsStyleSet*>(aData);
  styleSet->AppendStyleSheet(nsStyleSet::eAgentSheet, aSheet);
  return true;
}

static bool
PrependUserSheet(nsIStyleSheet *aSheet, void *aData)
{
  nsStyleSet *styleSet = static_cast<nsStyleSet*>(aData);
  styleSet->PrependStyleSheet(nsStyleSet::eUserSheet, aSheet);
  return true;
}

nsresult
nsDocumentViewer::CreateStyleSet(nsIDocument* aDocument,
                                   nsStyleSet** aStyleSet)
{
  // Make sure this does the same thing as PresShell::AddSheet wrt ordering.

  // this should eventually get expanded to allow for creating
  // different sets for different media
  nsStyleSet *styleSet = new nsStyleSet();

  styleSet->BeginUpdate();
  
  // The document will fill in the document sheets when we create the presshell
  
  // Handle the user sheets.
  nsCSSStyleSheet* sheet = nullptr;
  if (nsContentUtils::IsInChromeDocshell(aDocument)) {
    sheet = nsLayoutStylesheetCache::UserChromeSheet();
  }
  else {
    sheet = nsLayoutStylesheetCache::UserContentSheet();
  }

  if (sheet)
    styleSet->AppendStyleSheet(nsStyleSet::eUserSheet, sheet);

  // Append chrome sheets (scrollbars + forms).
  bool shouldOverride = false;
  // We don't want a docshell here for external resource docs, so just
  // look at mContainer.
  nsCOMPtr<nsIDocShell> ds(mContainer);
  nsCOMPtr<nsIDOMEventTarget> chromeHandler;
  nsCOMPtr<nsIURI> uri;
  nsRefPtr<nsCSSStyleSheet> csssheet;

  if (ds) {
    ds->GetChromeEventHandler(getter_AddRefs(chromeHandler));
  }
  if (chromeHandler) {
    nsCOMPtr<nsIDOMElement> elt(do_QueryInterface(chromeHandler));
    nsCOMPtr<nsIContent> content(do_QueryInterface(elt));
    if (elt && content) {
      nsCOMPtr<nsIURI> baseURI = content->GetBaseURI();

      nsAutoString sheets;
      elt->GetAttribute(NS_LITERAL_STRING("usechromesheets"), sheets);
      if (!sheets.IsEmpty() && baseURI) {
        nsRefPtr<mozilla::css::Loader> cssLoader = new mozilla::css::Loader();

        char *str = ToNewCString(sheets);
        char *newStr = str;
        char *token;
        while ( (token = nsCRT::strtok(newStr, ", ", &newStr)) ) {
          NS_NewURI(getter_AddRefs(uri), nsDependentCString(token), nullptr,
                    baseURI);
          if (!uri) continue;

          cssLoader->LoadSheetSync(uri, getter_AddRefs(csssheet));
          if (!csssheet) continue;

          styleSet->PrependStyleSheet(nsStyleSet::eAgentSheet, csssheet);
          shouldOverride = true;
        }
        nsMemory::Free(str);
      }
    }
  }

  if (!shouldOverride) {
    sheet = nsLayoutStylesheetCache::ScrollbarsSheet();
    if (sheet) {
      styleSet->PrependStyleSheet(nsStyleSet::eAgentSheet, sheet);
    }
  }

  sheet = nsLayoutStylesheetCache::NumberControlSheet();
  if (sheet) {
    styleSet->PrependStyleSheet(nsStyleSet::eAgentSheet, sheet);
  }

  sheet = nsLayoutStylesheetCache::FormsSheet();
  if (sheet) {
    styleSet->PrependStyleSheet(nsStyleSet::eAgentSheet, sheet);
  }

  sheet = nsLayoutStylesheetCache::FullScreenOverrideSheet();
  if (sheet) {
    styleSet->PrependStyleSheet(nsStyleSet::eOverrideSheet, sheet);
  }

  // Make sure to clone the quirk sheet so that it can be usefully
  // enabled/disabled as needed.
  nsRefPtr<nsCSSStyleSheet> quirkClone;
  nsCSSStyleSheet* quirkSheet;
  if (!nsLayoutStylesheetCache::UASheet() ||
      !(quirkSheet = nsLayoutStylesheetCache::QuirkSheet()) ||
      !(quirkClone = quirkSheet->Clone(nullptr, nullptr, nullptr, nullptr)) ||
      !sheet) {
    delete styleSet;
    return NS_ERROR_OUT_OF_MEMORY;
  }
  // quirk.css needs to come after the regular UA sheet (or more precisely,
  // after the html.css and so forth that the UA sheet imports).
  styleSet->PrependStyleSheet(nsStyleSet::eAgentSheet, quirkClone);
  styleSet->SetQuirkStyleSheet(quirkClone);
  styleSet->PrependStyleSheet(nsStyleSet::eAgentSheet,
                              nsLayoutStylesheetCache::UASheet());

  nsStyleSheetService *sheetService = nsStyleSheetService::GetInstance();
  if (sheetService) {
    sheetService->AgentStyleSheets()->EnumerateForwards(AppendAgentSheet,
                                                        styleSet);
    sheetService->UserStyleSheets()->EnumerateBackwards(PrependUserSheet,
                                                        styleSet);
  }

  // Caller will handle calling EndUpdate, per contract.
  *aStyleSet = styleSet;
  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::ClearHistoryEntry()
{
  mSHEntry = nullptr;
  return NS_OK;
}

//-------------------------------------------------------

nsresult
nsDocumentViewer::MakeWindow(const nsSize& aSize, nsView* aContainerView)
{
  if (GetIsPrintPreview())
    return NS_OK;

  bool shouldAttach = ShouldAttachToTopLevel();

  if (shouldAttach) {
    // If the old view is already attached to our parent, detach
    DetachFromTopLevelWidget();
  }

  mViewManager = new nsViewManager();

  nsDeviceContext *dx = mPresContext->DeviceContext();

  nsresult rv = mViewManager->Init(dx);
  if (NS_FAILED(rv))
    return rv;

  // The root view is always at 0,0.
  nsRect tbounds(nsPoint(0, 0), aSize);
  // Create a view
  nsView* view = mViewManager->CreateView(tbounds, aContainerView);
  if (!view)
    return NS_ERROR_OUT_OF_MEMORY;

  // Create a widget if we were given a parent widget or don't have a
  // container view that we can hook up to without a widget.
  // Don't create widgets for ResourceDocs (external resources & svg images),
  // because when they're displayed, they're painted into *another* document's
  // widget.
  if (!mDocument->IsResourceDoc() &&
      (mParentWidget || !aContainerView)) {
    // pass in a native widget to be the parent widget ONLY if the view hierarchy will stand alone.
    // otherwise the view will find its own parent widget and "do the right thing" to
    // establish a parent/child widget relationship
    nsWidgetInitData initData;
    nsWidgetInitData* initDataPtr;
    if (!mParentWidget) {
      initDataPtr = &initData;
      initData.mWindowType = eWindowType_invisible;
    } else {
      initDataPtr = nullptr;
    }

    if (shouldAttach) {
      // Reuse the top level parent widget.
      rv = view->AttachToTopLevelWidget(mParentWidget);
      mAttachedToParent = true;
    }
    else if (!aContainerView && mParentWidget) {
      rv = view->CreateWidgetForParent(mParentWidget, initDataPtr,
                                       true, false);
    }
    else {
      rv = view->CreateWidget(initDataPtr, true, false);
    }
    if (NS_FAILED(rv))
      return rv;
  }

  // Setup hierarchical relationship in view manager
  mViewManager->SetRootView(view);

  mWindow = view->GetWidget();

  // This SetFocus is necessary so the Arrow Key and Page Key events
  // go to the scrolled view as soon as the Window is created instead of going to
  // the browser window (this enables keyboard scrolling of the document)
  // mWindow->SetFocus();

  return rv;
}

void
nsDocumentViewer::DetachFromTopLevelWidget()
{
  if (mViewManager) {
    nsView* oldView = mViewManager->GetRootView();
    if (oldView && oldView->IsAttachedToTopLevel()) {
      oldView->DetachFromTopLevelWidget();
    }
  }
  mAttachedToParent = false;
}

nsView*
nsDocumentViewer::FindContainerView()
{
  nsView* containerView = nullptr;

  if (mContainer) {
    nsCOMPtr<nsIDocShellTreeItem> docShellItem(mContainer);
    nsCOMPtr<nsPIDOMWindow> pwin(do_GetInterface(docShellItem));
    if (pwin) {
      nsCOMPtr<nsIContent> containerElement = do_QueryInterface(pwin->GetFrameElementInternal());
      if (!containerElement) {
        return nullptr;
      }
      nsCOMPtr<nsIPresShell> parentPresShell;
      if (docShellItem) {
        nsCOMPtr<nsIDocShellTreeItem> parentDocShellItem;
        docShellItem->GetParent(getter_AddRefs(parentDocShellItem));
        if (parentDocShellItem) {
          nsCOMPtr<nsIDocShell> parentDocShell = do_QueryInterface(parentDocShellItem);
          parentPresShell = parentDocShell->GetPresShell();
        }
      }
      if (!parentPresShell) {
        nsCOMPtr<nsIDocument> parentDoc = containerElement->GetCurrentDoc();
        if (parentDoc) {
          parentPresShell = parentDoc->GetShell();
        }
      }
      if (!parentPresShell) {
        NS_WARNING("Subdocument container has no presshell");
      } else {
        nsIFrame* f = parentPresShell->GetRealPrimaryFrameFor(containerElement);
        if (f) {
          nsIFrame* subdocFrame = f->GetContentInsertionFrame();
          // subdocFrame might not be a subdocument frame; the frame
          // constructor can treat a <frame> as an inline in some XBL
          // cases. Treat that as display:none, the document is not
          // displayed.
          if (subdocFrame->GetType() == nsGkAtoms::subDocumentFrame) {
            NS_ASSERTION(subdocFrame->GetView(), "Subdoc frames must have views");
            nsView* innerView =
              static_cast<nsSubDocumentFrame*>(subdocFrame)->EnsureInnerView();
            containerView = innerView;
          } else {
            NS_WARNING("Subdocument container has non-subdocument frame");
          }
        } else {
          NS_WARNING("Subdocument container has no frame");
        }
      }
    }
  }

  return containerView;
}

nsresult
nsDocumentViewer::CreateDeviceContext(nsView* aContainerView)
{
  NS_PRECONDITION(!mPresShell && !mWindow,
                  "This will screw up our existing presentation");
  NS_PRECONDITION(mDocument, "Gotta have a document here");
  
  nsIDocument* doc = mDocument->GetDisplayDocument();
  if (doc) {
    NS_ASSERTION(!aContainerView, "External resource document embedded somewhere?");
    // We want to use our display document's device context if possible
    nsIPresShell* shell = doc->GetShell();
    if (shell) {
      nsPresContext* ctx = shell->GetPresContext();
      if (ctx) {
        mDeviceContext = ctx->DeviceContext();
        return NS_OK;
      }
    }
  }
  
  // Create a device context even if we already have one, since our widget
  // might have changed.
  nsIWidget* widget = nullptr;
  if (aContainerView) {
    widget = aContainerView->GetNearestWidget(nullptr);
  }
  if (!widget) {
    widget = mParentWidget;
  }
  if (widget) {
    widget = widget->GetTopLevelWidget();
  }

  mDeviceContext = new nsDeviceContext();
  mDeviceContext->Init(widget);
  return NS_OK;
}

// Return the selection for the document. Note that text fields have their
// own selection, which cannot be accessed with this method.
nsresult nsDocumentViewer::GetDocumentSelection(nsISelection **aSelection)
{
  NS_ENSURE_ARG_POINTER(aSelection);
  if (!mPresShell) {
    return NS_ERROR_NOT_INITIALIZED;
  }

  nsCOMPtr<nsISelectionController> selcon;
  selcon = do_QueryInterface(mPresShell);
  if (selcon)
    return selcon->GetSelection(nsISelectionController::SELECTION_NORMAL,
                                aSelection);
  return NS_ERROR_FAILURE;
}

/* ========================================================================================
 * nsIContentViewerEdit
 * ======================================================================================== */

NS_IMETHODIMP nsDocumentViewer::ClearSelection()
{
  nsresult rv;
  nsCOMPtr<nsISelection> selection;

  // use nsCopySupport::GetSelectionForCopy() ?
  rv = GetDocumentSelection(getter_AddRefs(selection));
  if (NS_FAILED(rv)) return rv;

  return selection->CollapseToStart();
}

NS_IMETHODIMP nsDocumentViewer::SelectAll()
{
  // XXX this is a temporary implementation copied from nsWebShell
  // for now. I think nsDocument and friends should have some helper
  // functions to make this easier.
  nsCOMPtr<nsISelection> selection;
  nsresult rv;

  // use nsCopySupport::GetSelectionForCopy() ?
  rv = GetDocumentSelection(getter_AddRefs(selection));
  if (NS_FAILED(rv)) return rv;

  nsCOMPtr<nsIDOMHTMLDocument> htmldoc = do_QueryInterface(mDocument);
  nsCOMPtr<nsIDOMNode> bodyNode;

  if (htmldoc)
  {
    nsCOMPtr<nsIDOMHTMLElement>bodyElement;
    rv = htmldoc->GetBody(getter_AddRefs(bodyElement));
    if (NS_FAILED(rv) || !bodyElement) return rv;

    bodyNode = do_QueryInterface(bodyElement);
  }
  else if (mDocument)
  {
    bodyNode = do_QueryInterface(mDocument->GetRootElement());
  }
  if (!bodyNode) return NS_ERROR_FAILURE;

  rv = selection->RemoveAllRanges();
  if (NS_FAILED(rv)) return rv;

  rv = selection->SelectAllChildren(bodyNode);
  return rv;
}

NS_IMETHODIMP nsDocumentViewer::CopySelection()
{
  nsCopySupport::FireClipboardEvent(NS_COPY, nsIClipboard::kGlobalClipboard, mPresShell, nullptr);
  return NS_OK;
}

NS_IMETHODIMP nsDocumentViewer::CopyLinkLocation()
{
  NS_ENSURE_TRUE(mPresShell, NS_ERROR_NOT_INITIALIZED);
  nsCOMPtr<nsIDOMNode> node;
  GetPopupLinkNode(getter_AddRefs(node));
  // make noise if we're not in a link
  NS_ENSURE_TRUE(node, NS_ERROR_FAILURE);

  nsCOMPtr<dom::Element> elm(do_QueryInterface(node));
  NS_ENSURE_TRUE(elm, NS_ERROR_FAILURE);

  nsAutoString locationText;
  nsContentUtils::GetLinkLocation(elm, locationText);
  if (locationText.IsEmpty())
    return NS_ERROR_FAILURE;

  nsresult rv = NS_OK;
  nsCOMPtr<nsIClipboardHelper> clipboard(do_GetService("@mozilla.org/widget/clipboardhelper;1", &rv));
  NS_ENSURE_SUCCESS(rv, rv);

  // copy the href onto the clipboard
  nsCOMPtr<nsIDOMDocument> doc = do_QueryInterface(mDocument);
  return clipboard->CopyString(locationText, doc);
}

NS_IMETHODIMP nsDocumentViewer::CopyImage(int32_t aCopyFlags)
{
  NS_ENSURE_TRUE(mPresShell, NS_ERROR_NOT_INITIALIZED);
  nsCOMPtr<nsIImageLoadingContent> node;
  GetPopupImageNode(getter_AddRefs(node));
  // make noise if we're not in an image
  NS_ENSURE_TRUE(node, NS_ERROR_FAILURE);

  nsCOMPtr<nsILoadContext> loadContext(mContainer);
  return nsCopySupport::ImageCopy(node, loadContext, aCopyFlags);
}


NS_IMETHODIMP nsDocumentViewer::GetCopyable(bool *aCopyable)
{
  NS_ENSURE_ARG_POINTER(aCopyable);
  *aCopyable = nsCopySupport::CanCopy(mDocument);
  return NS_OK;
}

/* AString getContents (in string mimeType, in boolean selectionOnly); */
NS_IMETHODIMP nsDocumentViewer::GetContents(const char *mimeType, bool selectionOnly, nsAString& aOutValue)
{
  aOutValue.Truncate();

  NS_ENSURE_TRUE(mPresShell, NS_ERROR_NOT_INITIALIZED);
  NS_ENSURE_TRUE(mDocument, NS_ERROR_NOT_INITIALIZED);

  // Now we have the selection.  Make sure it's nonzero:
  nsCOMPtr<nsISelection> sel;
  if (selectionOnly) {
    nsCopySupport::GetSelectionForCopy(mDocument, getter_AddRefs(sel));
    NS_ENSURE_TRUE(sel, NS_ERROR_FAILURE);
  
    bool isCollapsed;
    sel->GetIsCollapsed(&isCollapsed);
    if (isCollapsed)
      return NS_OK;
  }

  // call the copy code
  return nsCopySupport::GetContents(nsDependentCString(mimeType), 0, sel,
                                    mDocument, aOutValue);
}

/* readonly attribute boolean canGetContents; */
NS_IMETHODIMP nsDocumentViewer::GetCanGetContents(bool *aCanGetContents)
{
  NS_ENSURE_ARG_POINTER(aCanGetContents);
  *aCanGetContents = false;
  NS_ENSURE_STATE(mDocument);
  *aCanGetContents = nsCopySupport::CanCopy(mDocument);
  return NS_OK;
}


/* ========================================================================================
 * nsIContentViewerFile
 * ======================================================================================== */
/** ---------------------------------------------------
 *  See documentation above in the nsIContentViewerfile class definition
 *	@update 01/24/00 dwc
 */
NS_IMETHODIMP
nsDocumentViewer::Print(bool              aSilent,
                          FILE *            aDebugFile,
                          nsIPrintSettings* aPrintSettings)
{
#ifdef NS_PRINTING
  nsCOMPtr<nsIPrintSettings> printSettings;

#ifdef DEBUG
  nsresult rv = NS_ERROR_FAILURE;

  mDebugFile = aDebugFile;
  // if they don't pass in a PrintSettings, then make one
  // it will have all the default values
  printSettings = aPrintSettings;
  nsCOMPtr<nsIPrintOptions> printOptions = do_GetService(sPrintOptionsContractID, &rv);
  if (NS_SUCCEEDED(rv)) {
    // if they don't pass in a PrintSettings, then make one
    if (printSettings == nullptr) {
      printOptions->CreatePrintSettings(getter_AddRefs(printSettings));
    }
    NS_ASSERTION(printSettings, "You can't PrintPreview without a PrintSettings!");
  }
  if (printSettings) printSettings->SetPrintSilent(aSilent);
  if (printSettings) printSettings->SetShowPrintProgress(false);
#endif


  return Print(printSettings, nullptr);
#else
  return NS_ERROR_FAILURE;
#endif
}

// nsIContentViewerFile interface
NS_IMETHODIMP
nsDocumentViewer::GetPrintable(bool *aPrintable)
{
  NS_ENSURE_ARG_POINTER(aPrintable);

  *aPrintable = !GetIsPrinting();

  return NS_OK;
}

//*****************************************************************************
// nsIMarkupDocumentViewer
//*****************************************************************************

NS_IMETHODIMP nsDocumentViewer::ScrollToNode(nsIDOMNode* aNode)
{
  NS_ENSURE_ARG(aNode);
  NS_ENSURE_TRUE(mDocument, NS_ERROR_NOT_AVAILABLE);
  nsCOMPtr<nsIPresShell> presShell;
  NS_ENSURE_SUCCESS(GetPresShell(getter_AddRefs(presShell)), NS_ERROR_FAILURE);

  // Get the nsIContent interface, because that's what we need to
  // get the primary frame

  nsCOMPtr<nsIContent> content(do_QueryInterface(aNode));
  NS_ENSURE_TRUE(content, NS_ERROR_FAILURE);

  // Tell the PresShell to scroll to the primary frame of the content.
  NS_ENSURE_SUCCESS(
    presShell->ScrollContentIntoView(content,
                                     nsIPresShell::ScrollAxis(
                                       nsIPresShell::SCROLL_TOP,
                                       nsIPresShell::SCROLL_ALWAYS),
                                     nsIPresShell::ScrollAxis(),
                                     nsIPresShell::SCROLL_OVERFLOW_HIDDEN),
    NS_ERROR_FAILURE);
  return NS_OK;
}

void
nsDocumentViewer::CallChildren(CallChildFunc aFunc, void* aClosure)
{
  nsCOMPtr<nsIDocShell> docShell(mContainer);
  if (docShell)
  {
    int32_t i;
    int32_t n;
    docShell->GetChildCount(&n);
    for (i=0; i < n; i++)
    {
      nsCOMPtr<nsIDocShellTreeItem> child;
      docShell->GetChildAt(i, getter_AddRefs(child));
      nsCOMPtr<nsIDocShell> childAsShell(do_QueryInterface(child));
      NS_ASSERTION(childAsShell, "null child in docshell");
      if (childAsShell)
      {
        nsCOMPtr<nsIContentViewer> childCV;
        childAsShell->GetContentViewer(getter_AddRefs(childCV));
        if (childCV)
        {
          nsCOMPtr<nsIMarkupDocumentViewer> markupCV = do_QueryInterface(childCV);
          if (markupCV) {
            (*aFunc)(markupCV, aClosure);
          }
        }
      }
    }
  }
}

struct LineBoxInfo
{
  nscoord mMaxLineBoxWidth;
};

static void
ChangeChildPaintingEnabled(nsIMarkupDocumentViewer* aChild, void* aClosure)
{
  bool* enablePainting = (bool*) aClosure;
  if (*enablePainting) {
    aChild->ResumePainting();
  } else {
    aChild->PausePainting();
  }
}

static void
ChangeChildMaxLineBoxWidth(nsIMarkupDocumentViewer* aChild, void* aClosure)
{
  struct LineBoxInfo* lbi = (struct LineBoxInfo*) aClosure;
  aChild->ChangeMaxLineBoxWidth(lbi->mMaxLineBoxWidth);
}

struct ZoomInfo
{
  float mZoom;
};

static void
SetChildTextZoom(nsIMarkupDocumentViewer* aChild, void* aClosure)
{
  struct ZoomInfo* ZoomInfo = (struct ZoomInfo*) aClosure;
  aChild->SetTextZoom(ZoomInfo->mZoom);
}

static void
SetChildMinFontSize(nsIMarkupDocumentViewer* aChild, void* aClosure)
{
  nsCOMPtr<nsIMarkupDocumentViewer> branch =
    do_QueryInterface(aChild);
  branch->SetMinFontSize(NS_PTR_TO_INT32(aClosure));
}

static void
SetChildFullZoom(nsIMarkupDocumentViewer* aChild, void* aClosure)
{
  struct ZoomInfo* ZoomInfo = (struct ZoomInfo*) aClosure;
  aChild->SetFullZoom(ZoomInfo->mZoom);
}

static bool
SetExtResourceTextZoom(nsIDocument* aDocument, void* aClosure)
{
  // Would it be better to enumerate external resource viewers instead?
  nsIPresShell* shell = aDocument->GetShell();
  if (shell) {
    nsPresContext* ctxt = shell->GetPresContext();
    if (ctxt) {
      struct ZoomInfo* ZoomInfo = static_cast<struct ZoomInfo*>(aClosure);
      ctxt->SetTextZoom(ZoomInfo->mZoom);
    }
  }

  return true;
}

static bool
SetExtResourceMinFontSize(nsIDocument* aDocument, void* aClosure)
{
  nsIPresShell* shell = aDocument->GetShell();
  if (shell) {
    nsPresContext* ctxt = shell->GetPresContext();
    if (ctxt) {
      ctxt->SetBaseMinFontSize(NS_PTR_TO_INT32(aClosure));
    }
  }

  return true;
}

static bool
SetExtResourceFullZoom(nsIDocument* aDocument, void* aClosure)
{
  // Would it be better to enumerate external resource viewers instead?
  nsIPresShell* shell = aDocument->GetShell();
  if (shell) {
    nsPresContext* ctxt = shell->GetPresContext();
    if (ctxt) {
      struct ZoomInfo* ZoomInfo = static_cast<struct ZoomInfo*>(aClosure);
      ctxt->SetFullZoom(ZoomInfo->mZoom);
    }
  }

  return true;
}

NS_IMETHODIMP
nsDocumentViewer::SetTextZoom(float aTextZoom)
{
  // If we don't have a document, then we need to bail.
  if (!mDocument) {
    return NS_ERROR_FAILURE;
  }

  if (GetIsPrintPreview()) {
    return NS_OK;
  }

  mTextZoom = aTextZoom;

  // Set the text zoom on all children of mContainer (even if our zoom didn't
  // change, our children's zoom may be different, though it would be unusual).
  // Do this first, in case kids are auto-sizing and post reflow commands on
  // our presshell (which should be subsumed into our own style change reflow).
  struct ZoomInfo ZoomInfo = { aTextZoom };
  CallChildren(SetChildTextZoom, &ZoomInfo);

  // Now change our own zoom
  nsPresContext* pc = GetPresContext();
  if (pc && aTextZoom != mPresContext->TextZoom()) {
      pc->SetTextZoom(aTextZoom);
  }

  // And do the external resources
  mDocument->EnumerateExternalResources(SetExtResourceTextZoom, &ZoomInfo);

  nsContentUtils::DispatchChromeEvent(mDocument, static_cast<nsIDocument*>(mDocument),
                                      NS_LITERAL_STRING("TextZoomChange"),
                                      true, true);

  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::GetTextZoom(float* aTextZoom)
{
  NS_ENSURE_ARG_POINTER(aTextZoom);
  nsPresContext* pc = GetPresContext();
  *aTextZoom = pc ? pc->TextZoom() : 1.0f;
  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::SetMinFontSize(int32_t aMinFontSize)
{
  // If we don't have a document, then we need to bail.
  if (!mDocument) {
    return NS_ERROR_FAILURE;
  }

  if (GetIsPrintPreview()) {
    return NS_OK;
  }

  mMinFontSize = aMinFontSize;

  // Set the min font on all children of mContainer (even if our min font didn't
  // change, our children's min font may be different, though it would be unusual).
  // Do this first, in case kids are auto-sizing and post reflow commands on
  // our presshell (which should be subsumed into our own style change reflow).
  CallChildren(SetChildMinFontSize, NS_INT32_TO_PTR(aMinFontSize));

  // Now change our own min font
  nsPresContext* pc = GetPresContext();
  if (pc && aMinFontSize != mPresContext->MinFontSize(nullptr)) {
    pc->SetBaseMinFontSize(aMinFontSize);
  }

  // And do the external resources
  mDocument->EnumerateExternalResources(SetExtResourceMinFontSize,
                                        NS_INT32_TO_PTR(aMinFontSize));

  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::GetMinFontSize(int32_t* aMinFontSize)
{
  NS_ENSURE_ARG_POINTER(aMinFontSize);
  nsPresContext* pc = GetPresContext();
  *aMinFontSize = pc ? pc->BaseMinFontSize() : 0;
  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::SetFullZoom(float aFullZoom)
{
#ifdef NS_PRINT_PREVIEW
  if (GetIsPrintPreview()) {
    nsPresContext* pc = GetPresContext();
    NS_ENSURE_TRUE(pc, NS_OK);
    nsCOMPtr<nsIPresShell> shell = pc->GetPresShell();
    NS_ENSURE_TRUE(shell, NS_OK);

    if (!mPrintPreviewZoomed) {
      mOriginalPrintPreviewScale = pc->GetPrintPreviewScale();
      mPrintPreviewZoomed = true;
    }

    mPrintPreviewZoom = aFullZoom;
    pc->SetPrintPreviewScale(aFullZoom * mOriginalPrintPreviewScale);
    nsIPageSequenceFrame* pf = shell->GetPageSequenceFrame();
    if (pf) {
      nsIFrame* f = do_QueryFrame(pf);
      shell->FrameNeedsReflow(f, nsIPresShell::eResize, NS_FRAME_IS_DIRTY);
    }

    nsIFrame* rootFrame = shell->GetRootFrame();
    if (rootFrame) {
      rootFrame->InvalidateFrame();
    }
    return NS_OK;
  }
#endif

  // If we don't have a document, then we need to bail.
  if (!mDocument) {
    return NS_ERROR_FAILURE;
  }

  mPageZoom = aFullZoom;

  struct ZoomInfo ZoomInfo = { aFullZoom };
  CallChildren(SetChildFullZoom, &ZoomInfo);

  nsPresContext* pc = GetPresContext();
  if (pc) {
    pc->SetFullZoom(aFullZoom);
  }

  // And do the external resources
  mDocument->EnumerateExternalResources(SetExtResourceFullZoom, &ZoomInfo);

  nsContentUtils::DispatchChromeEvent(mDocument, static_cast<nsIDocument*>(mDocument),
                                      NS_LITERAL_STRING("FullZoomChange"),
                                      true, true);

  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::GetFullZoom(float* aFullZoom)
{
  NS_ENSURE_ARG_POINTER(aFullZoom);
#ifdef NS_PRINT_PREVIEW
  if (GetIsPrintPreview()) {
    *aFullZoom = mPrintPreviewZoom;
    return NS_OK;
  }
#endif
  // Check the prescontext first because it might have a temporary
  // setting for print-preview
  nsPresContext* pc = GetPresContext();
  *aFullZoom = pc ? pc->GetFullZoom() : mPageZoom;
  return NS_OK;
}

static void
SetChildAuthorStyleDisabled(nsIMarkupDocumentViewer* aChild, void* aClosure)
{
  bool styleDisabled  = *static_cast<bool*>(aClosure);
  aChild->SetAuthorStyleDisabled(styleDisabled);
}


NS_IMETHODIMP
nsDocumentViewer::SetAuthorStyleDisabled(bool aStyleDisabled)
{
  if (mPresShell) {
    mPresShell->SetAuthorStyleDisabled(aStyleDisabled);
  }
  CallChildren(SetChildAuthorStyleDisabled, &aStyleDisabled);
  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::GetAuthorStyleDisabled(bool* aStyleDisabled)
{
  if (mPresShell) {
    *aStyleDisabled = mPresShell->GetAuthorStyleDisabled();
  } else {
    *aStyleDisabled = false;
  }
  return NS_OK;
}

static bool
ExtResourceEmulateMedium(nsIDocument* aDocument, void* aClosure)
{
  nsIPresShell* shell = aDocument->GetShell();
  if (shell) {
    nsPresContext* ctxt = shell->GetPresContext();
    if (ctxt) {
      const nsAString* mediaType = static_cast<nsAString*>(aClosure);
      ctxt->EmulateMedium(*mediaType);
    }
  }

  return true;
}

static void
ChildEmulateMedium(nsIMarkupDocumentViewer* aChild, void* aClosure)
{
  const nsAString* mediaType = static_cast<nsAString*>(aClosure);
  aChild->EmulateMedium(*mediaType);
}

NS_IMETHODIMP
nsDocumentViewer::EmulateMedium(const nsAString& aMediaType)
{
  if (mPresContext) {
    mPresContext->EmulateMedium(aMediaType);
  }
  CallChildren(ChildEmulateMedium, const_cast<nsAString*>(&aMediaType));

  if (mDocument) {
    mDocument->EnumerateExternalResources(ExtResourceEmulateMedium,
                                          const_cast<nsAString*>(&aMediaType));
  }

  return NS_OK;
}

static bool
ExtResourceStopEmulatingMedium(nsIDocument* aDocument, void* aClosure)
{
  nsIPresShell* shell = aDocument->GetShell();
  if (shell) {
    nsPresContext* ctxt = shell->GetPresContext();
    if (ctxt) {
      ctxt->StopEmulatingMedium();
    }
  }

  return true;
}

static void
ChildStopEmulatingMedium(nsIMarkupDocumentViewer* aChild, void* aClosure)
{
  aChild->StopEmulatingMedium();
}

NS_IMETHODIMP
nsDocumentViewer::StopEmulatingMedium()
{
  if (mPresContext) {
    mPresContext->StopEmulatingMedium();
  }
  CallChildren(ChildStopEmulatingMedium, nullptr);

  if (mDocument) {
    mDocument->EnumerateExternalResources(ExtResourceStopEmulatingMedium,
                                          nullptr);
  }

  return NS_OK;
}

NS_IMETHODIMP nsDocumentViewer::GetForceCharacterSet(nsACString& aForceCharacterSet)
{
  aForceCharacterSet = mForceCharacterSet;
  return NS_OK;
}

static void
SetChildForceCharacterSet(nsIMarkupDocumentViewer* aChild, void* aClosure)
{
  const nsACString* charset = static_cast<nsACString*>(aClosure);
  aChild->SetForceCharacterSet(*charset);
}

NS_IMETHODIMP
nsDocumentViewer::SetForceCharacterSet(const nsACString& aForceCharacterSet)
{
  mForceCharacterSet = aForceCharacterSet;
  // now set the force char set on all children of mContainer
  CallChildren(SetChildForceCharacterSet, (void*) &aForceCharacterSet);
  return NS_OK;
}

NS_IMETHODIMP nsDocumentViewer::GetHintCharacterSet(nsACString& aHintCharacterSet)
{

  if(kCharsetUninitialized == mHintCharsetSource) {
    aHintCharacterSet.Truncate();
  } else {
    aHintCharacterSet = mHintCharset;
    // this can't possibly be right.  we can't set a value just because somebody got a related value!
    //mHintCharsetSource = kCharsetUninitialized;
  }
  return NS_OK;
}

NS_IMETHODIMP nsDocumentViewer::GetHintCharacterSetSource(int32_t *aHintCharacterSetSource)
{
  NS_ENSURE_ARG_POINTER(aHintCharacterSetSource);

  *aHintCharacterSetSource = mHintCharsetSource;
  return NS_OK;
}

static void
SetChildHintCharacterSetSource(nsIMarkupDocumentViewer* aChild, void* aClosure)
{
  aChild->SetHintCharacterSetSource(NS_PTR_TO_INT32(aClosure));
}

NS_IMETHODIMP
nsDocumentViewer::SetHintCharacterSetSource(int32_t aHintCharacterSetSource)
{
  mHintCharsetSource = aHintCharacterSetSource;
  // now set the hint char set source on all children of mContainer
  CallChildren(SetChildHintCharacterSetSource,
                      NS_INT32_TO_PTR(aHintCharacterSetSource));
  return NS_OK;
}

static void
SetChildHintCharacterSet(nsIMarkupDocumentViewer* aChild, void* aClosure)
{
  const nsACString* charset = static_cast<nsACString*>(aClosure);
  aChild->SetHintCharacterSet(*charset);
}

NS_IMETHODIMP
nsDocumentViewer::SetHintCharacterSet(const nsACString& aHintCharacterSet)
{
  mHintCharset = aHintCharacterSet;
  // now set the hint char set on all children of mContainer
  CallChildren(SetChildHintCharacterSet, (void*) &aHintCharacterSet);
  return NS_OK;
}

static void
AppendChildSubtree(nsIMarkupDocumentViewer* aChild, void* aClosure)
{
  nsTArray<nsCOMPtr<nsIMarkupDocumentViewer> >& array =
    *static_cast<nsTArray<nsCOMPtr<nsIMarkupDocumentViewer> >*>(aClosure);
  aChild->AppendSubtree(array);
}

NS_IMETHODIMP nsDocumentViewer::AppendSubtree(nsTArray<nsCOMPtr<nsIMarkupDocumentViewer> >& aArray)
{
  aArray.AppendElement(this);
  CallChildren(AppendChildSubtree, &aArray);
  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::PausePainting()
{
  bool enablePaint = false;
  CallChildren(ChangeChildPaintingEnabled, &enablePaint);

  nsIPresShell* presShell = GetPresShell();
  if (presShell) {
    presShell->PausePainting();
  }

  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::ResumePainting()
{
  bool enablePaint = true;
  CallChildren(ChangeChildPaintingEnabled, &enablePaint);

  nsIPresShell* presShell = GetPresShell();
  if (presShell) {
    presShell->ResumePainting();
  }

  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::ChangeMaxLineBoxWidth(int32_t aMaxLineBoxWidth)
{
  // Change the max line box width for all children.
  struct LineBoxInfo lbi = { aMaxLineBoxWidth };
  CallChildren(ChangeChildMaxLineBoxWidth, &lbi);

  // Now, change our max line box width.
  // Convert to app units, since our input is in CSS pixels.
  nscoord mlbw = nsPresContext::CSSPixelsToAppUnits(aMaxLineBoxWidth);
  nsIPresShell* presShell = GetPresShell();
  if (presShell) {
    presShell->SetMaxLineBoxWidth(mlbw);
  }

  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::GetContentSize(int32_t* aWidth, int32_t* aHeight)
{
   NS_ENSURE_TRUE(mDocument, NS_ERROR_NOT_AVAILABLE);

   // Skip doing this on docshell-less documents for now
   nsCOMPtr<nsIDocShellTreeItem> docShellAsItem(mContainer);
   NS_ENSURE_TRUE(docShellAsItem, NS_ERROR_NOT_AVAILABLE);
   
   nsCOMPtr<nsIDocShellTreeItem> docShellParent;
   docShellAsItem->GetSameTypeParent(getter_AddRefs(docShellParent));

   // It's only valid to access this from a top frame.  Doesn't work from
   // sub-frames.
   NS_ENSURE_TRUE(!docShellParent, NS_ERROR_FAILURE);

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

   // Flush out all content and style updates. We can't use a resize reflow
   // because it won't change some sizes that a style change reflow will.
   mDocument->FlushPendingNotifications(Flush_Layout);

  nsIFrame *root = presShell->GetRootFrame();
  NS_ENSURE_TRUE(root, NS_ERROR_FAILURE);

  nscoord prefWidth;
  {
    nsRefPtr<nsRenderingContext> rcx =
      presShell->CreateReferenceRenderingContext();
    prefWidth = root->GetPrefWidth(rcx);
  }

  nsresult rv = presShell->ResizeReflow(prefWidth, NS_UNCONSTRAINEDSIZE);
  NS_ENSURE_SUCCESS(rv, rv);

   nsRefPtr<nsPresContext> presContext;
   GetPresContext(getter_AddRefs(presContext));
   NS_ENSURE_TRUE(presContext, NS_ERROR_FAILURE);

   // so how big is it?
   nsRect shellArea = presContext->GetVisibleArea();
   // Protect against bogus returns here
   NS_ENSURE_TRUE(shellArea.width != NS_UNCONSTRAINEDSIZE &&
                  shellArea.height != NS_UNCONSTRAINEDSIZE,
                  NS_ERROR_FAILURE);

   *aWidth = presContext->AppUnitsToDevPixels(shellArea.width);
   *aHeight = presContext->AppUnitsToDevPixels(shellArea.height);

   return NS_OK;
}


NS_IMPL_ISUPPORTS(nsDocViewerSelectionListener, nsISelectionListener)

nsresult nsDocViewerSelectionListener::Init(nsDocumentViewer *aDocViewer)
{
  mDocViewer = aDocViewer;
  return NS_OK;
}

/*
 * GetPopupNode, GetPopupLinkNode and GetPopupImageNode are helpers
 * for the cmd_copyLink / cmd_copyImageLocation / cmd_copyImageContents family
 * of commands. The focus controller stores the popup node, these retrieve
 * them and munge appropriately. Note that we have to store the popup node
 * rather than retrieving it from EventStateManager::GetFocusedContent because
 * not all content (images included) can receive focus.
 */

nsresult
nsDocumentViewer::GetPopupNode(nsIDOMNode** aNode)
{
  NS_ENSURE_ARG_POINTER(aNode);

  *aNode = nullptr;

  // get the document
  nsIDocument* document = GetDocument();
  NS_ENSURE_TRUE(document, NS_ERROR_FAILURE);

  // get the private dom window
  nsCOMPtr<nsPIDOMWindow> window(document->GetWindow());
  NS_ENSURE_TRUE(window, NS_ERROR_NOT_AVAILABLE);
  if (window) {
    nsCOMPtr<nsPIWindowRoot> root = window->GetTopWindowRoot();
    NS_ENSURE_TRUE(root, NS_ERROR_FAILURE);

    // get the popup node
    nsCOMPtr<nsIDOMNode> node = root->GetPopupNode();
#ifdef MOZ_XUL
    if (!node) {
      nsPIDOMWindow* rootWindow = root->GetWindow();
      if (rootWindow) {
        nsCOMPtr<nsIDocument> rootDoc = rootWindow->GetExtantDoc();
        if (rootDoc) {
          nsXULPopupManager* pm = nsXULPopupManager::GetInstance();
          if (pm) {
            node = pm->GetLastTriggerPopupNode(rootDoc);
          }
        }
      }
    }
#endif
    node.swap(*aNode);
  }

  return NS_OK;
}

// GetPopupLinkNode: return popup link node or fail
nsresult
nsDocumentViewer::GetPopupLinkNode(nsIDOMNode** aNode)
{
  NS_ENSURE_ARG_POINTER(aNode);

  // you get null unless i say so
  *aNode = nullptr;

  // find popup node
  nsCOMPtr<nsIDOMNode> node;
  nsresult rv = GetPopupNode(getter_AddRefs(node));
  NS_ENSURE_SUCCESS(rv, rv);

  // find out if we have a link in our ancestry
  while (node) {

    nsCOMPtr<nsIContent> content(do_QueryInterface(node));
    if (content) {
      nsCOMPtr<nsIURI> hrefURI = content->GetHrefURI();
      if (hrefURI) {
        *aNode = node;
        NS_IF_ADDREF(*aNode); // addref
        return NS_OK;
      }
    }

    // get our parent and keep trying...
    nsCOMPtr<nsIDOMNode> parentNode;
    node->GetParentNode(getter_AddRefs(parentNode));
    node = parentNode;
  }

  // if we have no node, fail
  return NS_ERROR_FAILURE;
}

// GetPopupLinkNode: return popup image node or fail
nsresult
nsDocumentViewer::GetPopupImageNode(nsIImageLoadingContent** aNode)
{
  NS_ENSURE_ARG_POINTER(aNode);

  // you get null unless i say so
  *aNode = nullptr;

  // find popup node
  nsCOMPtr<nsIDOMNode> node;
  nsresult rv = GetPopupNode(getter_AddRefs(node));
  NS_ENSURE_SUCCESS(rv, rv);

  if (node)
    CallQueryInterface(node, aNode);

  return NS_OK;
}

/*
 * XXX dr
 * ------
 * These two functions -- GetInLink and GetInImage -- are kind of annoying
 * in that they only get called from the controller (in
 * nsDOMWindowController::IsCommandEnabled). The actual construction of the
 * context menus in communicator (nsContextMenu.js) has its own, redundant
 * tests. No big deal, but good to keep in mind if we ever clean context
 * menus.
 */

NS_IMETHODIMP nsDocumentViewer::GetInLink(bool* aInLink)
{
#ifdef DEBUG_dr
  printf("dr :: nsDocumentViewer::GetInLink\n");
#endif

  NS_ENSURE_ARG_POINTER(aInLink);

  // we're not in a link unless i say so
  *aInLink = false;

  // get the popup link
  nsCOMPtr<nsIDOMNode> node;
  nsresult rv = GetPopupLinkNode(getter_AddRefs(node));
  if (NS_FAILED(rv)) return rv;
  NS_ENSURE_TRUE(node, NS_ERROR_FAILURE);

  // if we made it here, we're in a link
  *aInLink = true;
  return NS_OK;
}

NS_IMETHODIMP nsDocumentViewer::GetInImage(bool* aInImage)
{
#ifdef DEBUG_dr
  printf("dr :: nsDocumentViewer::GetInImage\n");
#endif

  NS_ENSURE_ARG_POINTER(aInImage);

  // we're not in an image unless i say so
  *aInImage = false;

  // get the popup image
  nsCOMPtr<nsIImageLoadingContent> node;
  nsresult rv = GetPopupImageNode(getter_AddRefs(node));
  if (NS_FAILED(rv)) return rv;
  NS_ENSURE_TRUE(node, NS_ERROR_FAILURE);

  // if we made it here, we're in an image
  *aInImage = true;
  return NS_OK;
}

NS_IMETHODIMP nsDocViewerSelectionListener::NotifySelectionChanged(nsIDOMDocument *, nsISelection *, int16_t)
{
  NS_ASSERTION(mDocViewer, "Should have doc viewer!");

  // get the selection state
  nsCOMPtr<nsISelection> selection;
  nsresult rv = mDocViewer->GetDocumentSelection(getter_AddRefs(selection));
  if (NS_FAILED(rv)) return rv;

  bool selectionCollapsed;
  selection->GetIsCollapsed(&selectionCollapsed);
  // we only call UpdateCommands when the selection changes from collapsed
  // to non-collapsed or vice versa. We might need another update string
  // for simple selection changes, but that would be expenseive.
  if (!mGotSelectionState || mSelectionWasCollapsed != selectionCollapsed)
  {
    nsIDocument* theDoc = mDocViewer->GetDocument();
    if (!theDoc) return NS_ERROR_FAILURE;

    nsPIDOMWindow *domWindow = theDoc->GetWindow();
    if (!domWindow) return NS_ERROR_FAILURE;

    domWindow->UpdateCommands(NS_LITERAL_STRING("select"));
    mGotSelectionState = true;
    mSelectionWasCollapsed = selectionCollapsed;
  }

  return NS_OK;
}

//nsDocViewerFocusListener
NS_IMPL_ISUPPORTS(nsDocViewerFocusListener,
                  nsIDOMEventListener)

nsDocViewerFocusListener::nsDocViewerFocusListener()
:mDocViewer(nullptr)
{
}

nsDocViewerFocusListener::~nsDocViewerFocusListener(){}

nsresult
nsDocViewerFocusListener::HandleEvent(nsIDOMEvent* aEvent)
{
  NS_ENSURE_STATE(mDocViewer);

  nsCOMPtr<nsIPresShell> shell;
  mDocViewer->GetPresShell(getter_AddRefs(shell));
  NS_ENSURE_TRUE(shell, NS_ERROR_FAILURE);

  nsCOMPtr<nsISelectionController> selCon = do_QueryInterface(shell);
  int16_t selectionStatus;
  selCon->GetDisplaySelection(&selectionStatus);

  nsAutoString eventType;
  aEvent->GetType(eventType);
  if (eventType.EqualsLiteral("focus")) {
    // If selection was disabled, re-enable it.
    if(selectionStatus == nsISelectionController::SELECTION_DISABLED ||
       selectionStatus == nsISelectionController::SELECTION_HIDDEN) {
      selCon->SetDisplaySelection(nsISelectionController::SELECTION_ON);
      selCon->RepaintSelection(nsISelectionController::SELECTION_NORMAL);
    }
  } else {
    NS_ABORT_IF_FALSE(eventType.EqualsLiteral("blur"),
                      "Unexpected event type");
    // If selection was on, disable it.
    if(selectionStatus == nsISelectionController::SELECTION_ON ||
       selectionStatus == nsISelectionController::SELECTION_ATTENTION) {
      selCon->SetDisplaySelection(nsISelectionController::SELECTION_DISABLED);
      selCon->RepaintSelection(nsISelectionController::SELECTION_NORMAL);
    }
  }

  return NS_OK;
}

nsresult
nsDocViewerFocusListener::Init(nsDocumentViewer *aDocViewer)
{
  mDocViewer = aDocViewer;
  return NS_OK;
}

/** ---------------------------------------------------
 *  From nsIWebBrowserPrint
 */

#ifdef NS_PRINTING

NS_IMETHODIMP
nsDocumentViewer::Print(nsIPrintSettings*       aPrintSettings,
                          nsIWebProgressListener* aWebProgressListener)
{
  // Printing XUL documents is not supported.
  nsCOMPtr<nsIXULDocument> xulDoc(do_QueryInterface(mDocument));
  if (xulDoc) {
    return NS_ERROR_FAILURE;
  }

  if (!mContainer) {
    PR_PL(("Container was destroyed yet we are still trying to use it!"));
    return NS_ERROR_FAILURE;
  }

  nsCOMPtr<nsIDocShell> docShell(mContainer);
  NS_ENSURE_STATE(docShell);

  // Check to see if this document is still busy
  // If it is busy and we aren't already "queued" up to print then
  // Indicate there is a print pending and cache the args for later
  uint32_t busyFlags = nsIDocShell::BUSY_FLAGS_NONE;
  if ((NS_FAILED(docShell->GetBusyFlags(&busyFlags)) ||
       (busyFlags != nsIDocShell::BUSY_FLAGS_NONE && busyFlags & nsIDocShell::BUSY_FLAGS_PAGE_LOADING)) && 
      !mPrintDocIsFullyLoaded) {
    if (!mPrintIsPending) {
      mCachedPrintSettings           = aPrintSettings;
      mCachedPrintWebProgressListner = aWebProgressListener;
      mPrintIsPending                = true;
    }
    PR_PL(("Printing Stopped - document is still busy!"));
    return NS_ERROR_GFX_PRINTER_DOC_IS_BUSY;
  }

  if (!mDocument || !mDeviceContext) {
    PR_PL(("Can't Print without a document and a device context"));
    return NS_ERROR_FAILURE;
  }

  nsresult rv;

  // if we are printing another URL, then exit
  // the reason we check here is because this method can be called while
  // another is still in here (the printing dialog is a good example).
  // the only time we can print more than one job at a time is the regression tests
  if (GetIsPrinting()) {
    // Let the user know we are not ready to print.
    rv = NS_ERROR_NOT_AVAILABLE;
    nsPrintEngine::ShowPrintErrorDialog(rv);
    return rv;
  }

  nsAutoPtr<nsPrintEventDispatcher> beforeAndAfterPrint(
    new nsPrintEventDispatcher(mDocument));
  NS_ENSURE_STATE(!GetIsPrinting());
  // If we are hosting a full-page plugin, tell it to print
  // first. It shows its own native print UI.
  nsCOMPtr<nsIPluginDocument> pDoc(do_QueryInterface(mDocument));
  if (pDoc)
    return pDoc->Print();

  if (!mPrintEngine) {
    NS_ENSURE_STATE(mDeviceContext);
    mPrintEngine = new nsPrintEngine();

    rv = mPrintEngine->Initialize(this, mContainer, mDocument, 
                                  float(mDeviceContext->AppUnitsPerCSSInch()) /
                                  float(mDeviceContext->AppUnitsPerDevPixel()) /
                                  mPageZoom,
#ifdef DEBUG
                                  mDebugFile
#else
                                  nullptr
#endif
                                  );
    if (NS_FAILED(rv)) {
      mPrintEngine->Destroy();
      mPrintEngine = nullptr;
      return rv;
    }
  }
  if (mPrintEngine->HasPrintCallbackCanvas()) {
    mBeforeAndAfterPrint = beforeAndAfterPrint;
  }
  dom::Element* root = mDocument->GetRootElement();
  if (root && root->HasAttr(kNameSpaceID_None, nsGkAtoms::mozdisallowselectionprint)) {
    mPrintEngine->SetDisallowSelectionPrint(true);
  }
  if (root && root->HasAttr(kNameSpaceID_None, nsGkAtoms::moznomarginboxes)) {
    mPrintEngine->SetNoMarginBoxes(true);
  }
  rv = mPrintEngine->Print(aPrintSettings, aWebProgressListener);
  if (NS_FAILED(rv)) {
    OnDonePrinting();
  }
  return rv;
}

NS_IMETHODIMP
nsDocumentViewer::PrintPreview(nsIPrintSettings* aPrintSettings, 
                                 nsIDOMWindow *aChildDOMWin, 
                                 nsIWebProgressListener* aWebProgressListener)
{
#if defined(NS_PRINTING) && defined(NS_PRINT_PREVIEW)
  NS_WARN_IF_FALSE(IsInitializedForPrintPreview(),
                   "Using docshell.printPreview is the preferred way for print previewing!");

  NS_ENSURE_ARG_POINTER(aChildDOMWin);
  nsresult rv = NS_OK;

  if (GetIsPrinting()) {
    nsPrintEngine::CloseProgressDialog(aWebProgressListener);
    return NS_ERROR_FAILURE;
  }

  // Printing XUL documents is not supported.
  nsCOMPtr<nsIXULDocument> xulDoc(do_QueryInterface(mDocument));
  if (xulDoc) {
    nsPrintEngine::CloseProgressDialog(aWebProgressListener);
    return NS_ERROR_FAILURE;
  }

  nsCOMPtr<nsIDocShell> docShell(mContainer);
  if (!docShell || !mDeviceContext) {
    PR_PL(("Can't Print Preview without device context and docshell"));
    return NS_ERROR_FAILURE;
  }

  nsCOMPtr<nsIDOMDocument> domDoc;
  aChildDOMWin->GetDocument(getter_AddRefs(domDoc));
  nsCOMPtr<nsIDocument> doc = do_QueryInterface(domDoc);
  NS_ENSURE_STATE(doc);

  nsAutoPtr<nsPrintEventDispatcher> beforeAndAfterPrint(
    new nsPrintEventDispatcher(doc));
  NS_ENSURE_STATE(!GetIsPrinting());
  if (!mPrintEngine) {
    mPrintEngine = new nsPrintEngine();

    rv = mPrintEngine->Initialize(this, mContainer, doc,
                                  float(mDeviceContext->AppUnitsPerCSSInch()) /
                                  float(mDeviceContext->AppUnitsPerDevPixel()) /
                                  mPageZoom,
#ifdef DEBUG
                                  mDebugFile
#else
                                  nullptr
#endif
                                  );
    if (NS_FAILED(rv)) {
      mPrintEngine->Destroy();
      mPrintEngine = nullptr;
      return rv;
    }
  }
  if (mPrintEngine->HasPrintCallbackCanvas()) {
    mBeforeAndAfterPrint = beforeAndAfterPrint;
  }
  dom::Element* root = doc->GetRootElement();
  if (root && root->HasAttr(kNameSpaceID_None, nsGkAtoms::mozdisallowselectionprint)) {
    PR_PL(("PrintPreview: found mozdisallowselectionprint"));
    mPrintEngine->SetDisallowSelectionPrint(true);
  }
  if (root && root->HasAttr(kNameSpaceID_None, nsGkAtoms::moznomarginboxes)) {
    PR_PL(("PrintPreview: found moznomarginboxes"));
    mPrintEngine->SetNoMarginBoxes(true);
  }
  rv = mPrintEngine->PrintPreview(aPrintSettings, aChildDOMWin, aWebProgressListener);
  mPrintPreviewZoomed = false;
  if (NS_FAILED(rv)) {
    OnDonePrinting();
  }
  return rv;
#else
  return NS_ERROR_FAILURE;
#endif
}

//----------------------------------------------------------------------
NS_IMETHODIMP
nsDocumentViewer::PrintPreviewNavigate(int16_t aType, int32_t aPageNum)
{
  if (!GetIsPrintPreview() ||
      mPrintEngine->GetIsCreatingPrintPreview())
    return NS_ERROR_FAILURE;

  nsIScrollableFrame* sf =
    mPrintEngine->GetPrintPreviewPresShell()->GetRootScrollFrameAsScrollable();
  if (!sf)
    return NS_OK;

  // Check to see if we can short circut scrolling to the top
  if (aType == nsIWebBrowserPrint::PRINTPREVIEW_HOME ||
      (aType == nsIWebBrowserPrint::PRINTPREVIEW_GOTO_PAGENUM && aPageNum == 1)) {
    sf->ScrollTo(nsPoint(0, 0), nsIScrollableFrame::INSTANT);
    return NS_OK;
  }

  // Finds the SimplePageSequencer frame
  // in PP mPrtPreview->mPrintObject->mSeqFrame is null
  nsIFrame* seqFrame  = nullptr;
  int32_t   pageCount = 0;
  if (NS_FAILED(mPrintEngine->GetSeqFrameAndCountPages(seqFrame, pageCount))) {
    return NS_ERROR_FAILURE;
  }

  // Figure where we are currently scrolled to
  nsPoint pt = sf->GetScrollPosition();

  int32_t    pageNum = 1;
  nsIFrame * fndPageFrame  = nullptr;
  nsIFrame * currentPage   = nullptr;

  // If it is "End" then just do a "goto" to the last page
  if (aType == nsIWebBrowserPrint::PRINTPREVIEW_END) {
    aType    = nsIWebBrowserPrint::PRINTPREVIEW_GOTO_PAGENUM;
    aPageNum = pageCount;
  }

  // Now, locate the current page we are on and
  // and the page of the page number
  nsIFrame* pageFrame = seqFrame->GetFirstPrincipalChild();
  while (pageFrame != nullptr) {
    nsRect pageRect = pageFrame->GetRect();
    if (pageRect.Contains(pageRect.x, pt.y)) {
      currentPage = pageFrame;
    }
    if (pageNum == aPageNum) {
      fndPageFrame = pageFrame;
      break;
    }
    pageNum++;
    pageFrame = pageFrame->GetNextSibling();
  }

  if (aType == nsIWebBrowserPrint::PRINTPREVIEW_PREV_PAGE) {
    if (currentPage) {
      fndPageFrame = currentPage->GetPrevInFlow();
      if (!fndPageFrame) {
        return NS_OK;
      }
    } else {
      return NS_OK;
    }
  } else if (aType == nsIWebBrowserPrint::PRINTPREVIEW_NEXT_PAGE) {
    if (currentPage) {
      fndPageFrame = currentPage->GetNextInFlow();
      if (!fndPageFrame) {
        return NS_OK;
      }
    } else {
      return NS_OK;
    }
  } else { // If we get here we are doing "GoTo"
    if (aPageNum < 0 || aPageNum > pageCount) {
      return NS_OK;
    }
  }

  if (fndPageFrame) {
    nscoord newYPosn =
      nscoord(mPrintEngine->GetPrintPreviewScale() * fndPageFrame->GetPosition().y);
    sf->ScrollTo(nsPoint(pt.x, newYPosn), nsIScrollableFrame::INSTANT);
  }
  return NS_OK;

}

/* readonly attribute nsIPrintSettings globalPrintSettings; */
NS_IMETHODIMP
nsDocumentViewer::GetGlobalPrintSettings(nsIPrintSettings * *aGlobalPrintSettings)
{
  return nsPrintEngine::GetGlobalPrintSettings(aGlobalPrintSettings);
}

/* readonly attribute boolean doingPrint; */
// XXX This always returns false for subdocuments
NS_IMETHODIMP
nsDocumentViewer::GetDoingPrint(bool *aDoingPrint)
{
  NS_ENSURE_ARG_POINTER(aDoingPrint);
  
  *aDoingPrint = false;
  if (mPrintEngine) {
    // XXX shouldn't this be GetDoingPrint() ?
    return mPrintEngine->GetDoingPrintPreview(aDoingPrint);
  } 
  return NS_OK;
}

/* readonly attribute boolean doingPrintPreview; */
// XXX This always returns false for subdocuments
NS_IMETHODIMP
nsDocumentViewer::GetDoingPrintPreview(bool *aDoingPrintPreview)
{
  NS_ENSURE_ARG_POINTER(aDoingPrintPreview);

  *aDoingPrintPreview = false;
  if (mPrintEngine) {
    return mPrintEngine->GetDoingPrintPreview(aDoingPrintPreview);
  }
  return NS_OK;
}

/* readonly attribute nsIPrintSettings currentPrintSettings; */
NS_IMETHODIMP
nsDocumentViewer::GetCurrentPrintSettings(nsIPrintSettings * *aCurrentPrintSettings)
{
  NS_ENSURE_ARG_POINTER(aCurrentPrintSettings);

  *aCurrentPrintSettings = nullptr;
  NS_ENSURE_TRUE(mPrintEngine, NS_ERROR_FAILURE);

  return mPrintEngine->GetCurrentPrintSettings(aCurrentPrintSettings);
}


/* readonly attribute nsIDOMWindow currentChildDOMWindow; */
NS_IMETHODIMP 
nsDocumentViewer::GetCurrentChildDOMWindow(nsIDOMWindow * *aCurrentChildDOMWindow)
{
  NS_ENSURE_ARG_POINTER(aCurrentChildDOMWindow);
  *aCurrentChildDOMWindow = nullptr;
  return NS_ERROR_NOT_IMPLEMENTED;
}

/* void cancel (); */
NS_IMETHODIMP
nsDocumentViewer::Cancel()
{
  NS_ENSURE_TRUE(mPrintEngine, NS_ERROR_FAILURE);
  return mPrintEngine->Cancelled();
}

/* void exitPrintPreview (); */
NS_IMETHODIMP
nsDocumentViewer::ExitPrintPreview()
{
  if (GetIsPrinting())
    return NS_ERROR_FAILURE;
  NS_ENSURE_TRUE(mPrintEngine, NS_ERROR_FAILURE);

  if (GetIsPrintPreview()) {
    ReturnToGalleyPresentation();
  }
  return NS_OK;
}

//----------------------------------------------------------------------------------
// Enumerate all the documents for their titles
NS_IMETHODIMP
nsDocumentViewer::EnumerateDocumentNames(uint32_t* aCount,
                                           char16_t*** aResult)
{
#ifdef NS_PRINTING
  NS_ENSURE_ARG(aCount);
  NS_ENSURE_ARG_POINTER(aResult);
  NS_ENSURE_TRUE(mPrintEngine, NS_ERROR_FAILURE);

  return mPrintEngine->EnumerateDocumentNames(aCount, aResult);
#else
  return NS_ERROR_FAILURE;
#endif
}

/* readonly attribute boolean isFramesetFrameSelected; */
NS_IMETHODIMP 
nsDocumentViewer::GetIsFramesetFrameSelected(bool *aIsFramesetFrameSelected)
{
#ifdef NS_PRINTING
  *aIsFramesetFrameSelected = false;
  NS_ENSURE_TRUE(mPrintEngine, NS_ERROR_FAILURE);

  return mPrintEngine->GetIsFramesetFrameSelected(aIsFramesetFrameSelected);
#else
  return NS_ERROR_FAILURE;
#endif
}

/* readonly attribute long printPreviewNumPages; */
NS_IMETHODIMP
nsDocumentViewer::GetPrintPreviewNumPages(int32_t *aPrintPreviewNumPages)
{
#ifdef NS_PRINTING
  NS_ENSURE_ARG_POINTER(aPrintPreviewNumPages);
  NS_ENSURE_TRUE(mPrintEngine, NS_ERROR_FAILURE);

  return mPrintEngine->GetPrintPreviewNumPages(aPrintPreviewNumPages);
#else
  return NS_ERROR_FAILURE;
#endif
}

/* readonly attribute boolean isFramesetDocument; */
NS_IMETHODIMP
nsDocumentViewer::GetIsFramesetDocument(bool *aIsFramesetDocument)
{
#ifdef NS_PRINTING
  *aIsFramesetDocument = false;
  NS_ENSURE_TRUE(mPrintEngine, NS_ERROR_FAILURE);

  return mPrintEngine->GetIsFramesetDocument(aIsFramesetDocument);
#else
  return NS_ERROR_FAILURE;
#endif
}

/* readonly attribute boolean isIFrameSelected; */
NS_IMETHODIMP 
nsDocumentViewer::GetIsIFrameSelected(bool *aIsIFrameSelected)
{
#ifdef NS_PRINTING
  *aIsIFrameSelected = false;
  NS_ENSURE_TRUE(mPrintEngine, NS_ERROR_FAILURE);

  return mPrintEngine->GetIsIFrameSelected(aIsIFrameSelected);
#else
  return NS_ERROR_FAILURE;
#endif
}

/* readonly attribute boolean isRangeSelection; */
NS_IMETHODIMP 
nsDocumentViewer::GetIsRangeSelection(bool *aIsRangeSelection)
{
#ifdef NS_PRINTING
  *aIsRangeSelection = false;
  NS_ENSURE_TRUE(mPrintEngine, NS_ERROR_FAILURE);

  return mPrintEngine->GetIsRangeSelection(aIsRangeSelection);
#else
  return NS_ERROR_FAILURE;
#endif
}

//----------------------------------------------------------------------------------
// Printing/Print Preview Helpers
//----------------------------------------------------------------------------------

//----------------------------------------------------------------------------------
// Walks the document tree and tells each DocShell whether Printing/PP is happening
void 
nsDocumentViewer::SetIsPrintingInDocShellTree(nsIDocShellTreeItem* aParentNode, 
                                                bool                 aIsPrintingOrPP, 
                                                bool                 aStartAtTop)
{
  nsCOMPtr<nsIDocShellTreeItem> parentItem(do_QueryInterface(aParentNode));

  // find top of "same parent" tree
  if (aStartAtTop) {
    if (aIsPrintingOrPP) {
      while (parentItem) {
        nsCOMPtr<nsIDocShellTreeItem> parent;
        parentItem->GetSameTypeParent(getter_AddRefs(parent));
        if (!parent) {
          break;
        }
        parentItem = do_QueryInterface(parent);
      }
      mTopContainerWhilePrinting = do_GetWeakReference(parentItem);
    } else {
      parentItem = do_QueryReferent(mTopContainerWhilePrinting);
    }
  }

  // Check to see if the DocShell's ContentViewer is printing/PP
  nsCOMPtr<nsIContentViewerContainer> viewerContainer(do_QueryInterface(parentItem));
  if (viewerContainer) {
    viewerContainer->SetIsPrinting(aIsPrintingOrPP);
  }

  if (!aParentNode) {
    return;
  }

  // Traverse children to see if any of them are printing.
  int32_t n;
  aParentNode->GetChildCount(&n);
  for (int32_t i=0; i < n; i++) {
    nsCOMPtr<nsIDocShellTreeItem> child;
    aParentNode->GetChildAt(i, getter_AddRefs(child));
    NS_ASSERTION(child, "child isn't nsIDocShell");
    if (child) {
      SetIsPrintingInDocShellTree(child, aIsPrintingOrPP, false);
    }
  }

}
#endif // NS_PRINTING

bool
nsDocumentViewer::ShouldAttachToTopLevel()
{
  if (!mParentWidget)
    return false;

  nsCOMPtr<nsIDocShellTreeItem> containerItem(mContainer);
  if (!containerItem)
    return false;

  // We always attach when using puppet widgets
  if (nsIWidget::UsePuppetWidgets())
    return true;

#if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
  // On windows, in the parent process we also attach, but just to
  // chrome items
  nsWindowType winType = mParentWidget->WindowType();
  if ((winType == eWindowType_toplevel ||
       winType == eWindowType_dialog ||
       winType == eWindowType_invisible) &&
      containerItem->ItemType() == nsIDocShellTreeItem::typeChrome) {
    return true;
  }
#endif

  return false;
}

bool CollectDocuments(nsIDocument* aDocument, void* aData)
{
  if (aDocument) {
    static_cast<nsCOMArray<nsIDocument>*>(aData)->AppendObject(aDocument);
    aDocument->EnumerateSubDocuments(CollectDocuments, aData);
  }
  return true;
}

void
nsDocumentViewer::DispatchEventToWindowTree(nsIDocument* aDoc,
                                              const nsAString& aEvent)
{
  nsCOMArray<nsIDocument> targets;
  CollectDocuments(aDoc, &targets);
  for (int32_t i = 0; i < targets.Count(); ++i) {
    nsIDocument* d = targets[i];
    nsContentUtils::DispatchTrustedEvent(d, d->GetWindow(),
                                         aEvent, false, false, nullptr);
  }
}

//------------------------------------------------------------
// XXX this always returns false for subdocuments
bool
nsDocumentViewer::GetIsPrinting()
{
#ifdef NS_PRINTING
  if (mPrintEngine) {
    return mPrintEngine->GetIsPrinting();
  }
#endif
  return false; 
}

//------------------------------------------------------------
// Notification from the PrintEngine of the current Printing status
void
nsDocumentViewer::SetIsPrinting(bool aIsPrinting)
{
#ifdef NS_PRINTING
  // Set all the docShells in the docshell tree to be printing.
  // that way if anyone of them tries to "navigate" it can't
  nsCOMPtr<nsIDocShell> docShell(mContainer);
  if (docShell || !aIsPrinting) {
    SetIsPrintingInDocShellTree(docShell, aIsPrinting, true);
  } else {
    NS_WARNING("Did you close a window before printing?");
  }

  if (!aIsPrinting) {
    mBeforeAndAfterPrint = nullptr;
  }
#endif
}

//------------------------------------------------------------
// The PrintEngine holds the current value
// this called from inside the DocViewer.
// XXX it always returns false for subdocuments
bool
nsDocumentViewer::GetIsPrintPreview()
{
#ifdef NS_PRINTING
  if (mPrintEngine) {
    return mPrintEngine->GetIsPrintPreview();
  }
#endif
  return false; 
}

//------------------------------------------------------------
// Notification from the PrintEngine of the current PP status
void
nsDocumentViewer::SetIsPrintPreview(bool aIsPrintPreview)
{
#ifdef NS_PRINTING
  // Set all the docShells in the docshell tree to be printing.
  // that way if anyone of them tries to "navigate" it can't
  nsCOMPtr<nsIDocShell> docShell(mContainer);
  if (docShell || !aIsPrintPreview) {
    SetIsPrintingInDocShellTree(docShell, aIsPrintPreview, true);
  }
  if (!aIsPrintPreview) {
    mBeforeAndAfterPrint = nullptr;
  }
#endif
  if (!aIsPrintPreview) {
    if (mPresShell) {
      DestroyPresShell();
    }
    mWindow = nullptr;
    mViewManager = nullptr;
    mPresContext = nullptr;
    mPresShell = nullptr;
  }
}

//----------------------------------------------------------------------------------
// nsIDocumentViewerPrint IFace
//----------------------------------------------------------------------------------

//------------------------------------------------------------
void
nsDocumentViewer::IncrementDestroyRefCount()
{
  ++mDestroyRefCount;
}

//------------------------------------------------------------

#if defined(NS_PRINTING) && defined(NS_PRINT_PREVIEW)
//------------------------------------------------------------
// Reset ESM focus for all descendent doc shells.
static void
ResetFocusState(nsIDocShell* aDocShell)
{
  nsIFocusManager* fm = nsFocusManager::GetFocusManager();
  if (!fm)
    return;

  nsCOMPtr<nsISimpleEnumerator> docShellEnumerator;
  aDocShell->GetDocShellEnumerator(nsIDocShellTreeItem::typeContent,
                                   nsIDocShell::ENUMERATE_FORWARDS,
                                   getter_AddRefs(docShellEnumerator));
  
  nsCOMPtr<nsISupports> currentContainer;
  bool hasMoreDocShells;
  while (NS_SUCCEEDED(docShellEnumerator->HasMoreElements(&hasMoreDocShells))
         && hasMoreDocShells) {
    docShellEnumerator->GetNext(getter_AddRefs(currentContainer));
    nsCOMPtr<nsIDOMWindow> win = do_GetInterface(currentContainer);
    if (win)
      fm->ClearFocus(win);
  }
}
#endif // NS_PRINTING && NS_PRINT_PREVIEW

void
nsDocumentViewer::ReturnToGalleyPresentation()
{
#if defined(NS_PRINTING) && defined(NS_PRINT_PREVIEW)
  if (!GetIsPrintPreview()) {
    NS_ERROR("Wow, we should never get here!");
    return;
  }

  SetIsPrintPreview(false);

  mPrintEngine->TurnScriptingOn(true);
  mPrintEngine->Destroy();
  mPrintEngine = nullptr;

  nsCOMPtr<nsIDocShell> docShell(mContainer);
  ResetFocusState(docShell);

  SetTextZoom(mTextZoom);
  SetFullZoom(mPageZoom);
  SetMinFontSize(mMinFontSize);
  Show();

#endif // NS_PRINTING && NS_PRINT_PREVIEW
}

//------------------------------------------------------------
// This called ONLY when printing has completed and the DV
// is being notified that it should get rid of the PrintEngine.
//
// BUT, if we are in Print Preview then we want to ignore the 
// notification (we do not get rid of the PrintEngine)
// 
// One small caveat: 
//   This IS called from two places in this module for cleaning
//   up when an error occurred during the start up printing 
//   and print preview
//
void
nsDocumentViewer::OnDonePrinting() 
{
#if defined(NS_PRINTING) && defined(NS_PRINT_PREVIEW)
  if (mPrintEngine) {
    nsRefPtr<nsPrintEngine> pe = mPrintEngine;
    if (GetIsPrintPreview()) {
      pe->DestroyPrintingData();
    } else {
      mPrintEngine = nullptr;
      pe->Destroy();
    }

    // We are done printing, now cleanup 
    if (mDeferredWindowClose) {
      mDeferredWindowClose = false;
      nsCOMPtr<nsIDOMWindow> win =
        do_GetInterface(static_cast<nsIDocShell*>(mContainer));
      if (win)
        win->Close();
    } else if (mClosingWhilePrinting) {
      if (mDocument) {
        mDocument->SetScriptGlobalObject(nullptr);
        mDocument->Destroy();
        mDocument = nullptr;
      }
      mClosingWhilePrinting = false;
    }
  }
#endif // NS_PRINTING && NS_PRINT_PREVIEW
}

NS_IMETHODIMP nsDocumentViewer::SetPageMode(bool aPageMode, nsIPrintSettings* aPrintSettings)
{
  // XXX Page mode is only partially working; it's currently used for
  // reftests that require a paginated context
  mIsPageMode = aPageMode;

  if (mPresShell) {
    DestroyPresShell();
  }

  if (mPresContext) {
    DestroyPresContext();
  }

  mViewManager  = nullptr;
  mWindow       = nullptr;

  NS_ENSURE_STATE(mDocument);
  if (aPageMode)
  {    
    mPresContext = CreatePresContext(mDocument,
        nsPresContext::eContext_PageLayout, FindContainerView());
    NS_ENSURE_TRUE(mPresContext, NS_ERROR_OUT_OF_MEMORY);
    mPresContext->SetPaginatedScrolling(true);
    mPresContext->SetPrintSettings(aPrintSettings);
    nsresult rv = mPresContext->Init(mDeviceContext);
    NS_ENSURE_SUCCESS(rv, rv);
  }
  InitInternal(mParentWidget, nullptr, mBounds, true, false);

  Show();
  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::GetHistoryEntry(nsISHEntry **aHistoryEntry)
{
  NS_IF_ADDREF(*aHistoryEntry = mSHEntry);
  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::GetIsTabModalPromptAllowed(bool *aAllowed)
{
  *aAllowed = !mHidden;
  return NS_OK;
}

NS_IMETHODIMP
nsDocumentViewer::GetIsHidden(bool *aHidden)
{
  *aHidden = mHidden;
  return NS_OK;
}

void
nsDocumentViewer::DestroyPresShell()
{
  // Break circular reference (or something)
  mPresShell->EndObservingDocument();

  nsCOMPtr<nsISelection> selection;
  GetDocumentSelection(getter_AddRefs(selection));
  nsCOMPtr<nsISelectionPrivate> selPrivate = do_QueryInterface(selection);
  if (selPrivate && mSelectionListener)
    selPrivate->RemoveSelectionListener(mSelectionListener);

  nsAutoScriptBlocker scriptBlocker;
  mPresShell->Destroy();
  mPresShell = nullptr;
}

void
nsDocumentViewer::DestroyPresContext()
{
  mPresContext->Detach();
  mPresContext = nullptr;
}

bool
nsDocumentViewer::IsInitializedForPrintPreview()
{
  return mInitializedForPrintPreview;
}

void
nsDocumentViewer::InitializeForPrintPreview()
{
  mInitializedForPrintPreview = true;
}

void
nsDocumentViewer::SetPrintPreviewPresentation(nsViewManager* aViewManager,
                                                nsPresContext* aPresContext,
                                                nsIPresShell* aPresShell)
{
  if (mPresShell) {
    DestroyPresShell();
  }

  mWindow = nullptr;
  mViewManager = aViewManager;
  mPresContext = aPresContext;
  mPresShell = aPresShell;
}

// Fires the "document-shown" event so that interested parties are aware of it.
NS_IMETHODIMP
nsDocumentShownDispatcher::Run()
{
  nsCOMPtr<nsIObserverService> observerService =
    mozilla::services::GetObserverService();
  if (observerService) {
    observerService->NotifyObservers(mDocument, "document-shown", nullptr);
  }
  return NS_OK;
}