/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 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/. */

#ifndef nsLayoutStatics_h__

#define nsLayoutStatics_h__

#include "nscore.h"

#include "MainThreadUtils.h"

#include "nsISupportsImpl.h"

#include "nsDebug.h"

// This isn't really a class, it's a namespace for static methods.

// Documents and other objects can hold a reference to the layout static

// objects so that they last past the xpcom-shutdown notification.

class nsLayoutStatics

{

public:

  // Called by the layout module constructor. This call performs an AddRef()

  // internally.

  static nsresult Initialize();

  static void AddRef()

  {

    NS_ASSERTION(NS_IsMainThread(),

                 "nsLayoutStatics reference counting must be on main thread");

    NS_ASSERTION(sLayoutStaticRefcnt,

                 "nsLayoutStatics already dropped to zero!");

    ++sLayoutStaticRefcnt;

    NS_LOG_ADDREF(&sLayoutStaticRefcnt, sLayoutStaticRefcnt,

                  "nsLayoutStatics", 1);

  }

  static void Release()

  {

    NS_ASSERTION(NS_IsMainThread(),

                 "nsLayoutStatics reference counting must be on main thread");

    --sLayoutStaticRefcnt;

    NS_LOG_RELEASE(&sLayoutStaticRefcnt, sLayoutStaticRefcnt,

                   "nsLayoutStatics");

    if (!sLayoutStaticRefcnt)

      Shutdown();

  }

private:

  // not to be called!

  nsLayoutStatics();

  static void Shutdown();

  static nsrefcnt sLayoutStaticRefcnt;

};

class nsLayoutStaticsRef

{

public:

  nsLayoutStaticsRef()

  {

    nsLayoutStatics::AddRef();

  }

  ~nsLayoutStaticsRef()

  {

    nsLayoutStatics::Release();

  }

};

#endif // nsLayoutStatics_h__