widget/nsAutoRollup.cpp
author Joel Maher <jmaher@mozilla.com>
Wed, 11 Oct 2017 08:45:06 -0400
changeset 432365 42c1b2dc8bac015e691fb2e17c95f60f6cb144aa
parent 395735 40479d157fc874df89dd7b7f959f761319aece49
child 505383 6f3709b3878117466168c40affa7bca0b60cf75b
permissions -rw-r--r--
Bug 1396803 - Disable test_tabbar_session_restore_button.py TestNoTabbarSessionRestoreButton.test_pref_off_button_does_not_show on osx for frequent failures. r=me, a=test-only

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

#include "mozilla/widget/nsAutoRollup.h"

namespace mozilla {
namespace widget {

/*static*/ uint32_t nsAutoRollup::sCount = 0;
/*static*/ StaticRefPtr<nsIContent> nsAutoRollup::sLastRollup;

nsAutoRollup::nsAutoRollup()
{
  // remember if sLastRollup was null, and only clear it upon destruction
  // if so. This prevents recursive usage of nsAutoRollup from clearing
  // sLastRollup when it shouldn't.
  mWasClear = !sLastRollup;
  sCount++;
}

nsAutoRollup::nsAutoRollup(nsIContent* aRollup)
{
  MOZ_ASSERT(!sLastRollup);
  mWasClear = true;
  sCount++;
  SetLastRollup(aRollup);
}

nsAutoRollup::~nsAutoRollup()
{
  if (sLastRollup && mWasClear) {
    sLastRollup = nullptr;
  }
  sCount--;
}

/*static*/ void
nsAutoRollup::SetLastRollup(nsIContent* aLastRollup)
{
  // There must be at least one nsAutoRollup on the stack.
  MOZ_ASSERT(sCount);

  sLastRollup = aLastRollup;
}

/*static*/ nsIContent*
nsAutoRollup::GetLastRollup()
{
  return sLastRollup.get();
}

} // namespace widget
} // namespace mozilla