static void
CopyList()
{
  const ProtectedAirspaceWarningManager::Lease lease(*airspace_warnings);

  warning_list.clear();
  for (auto i = lease->begin(), end = lease->end();
       i != end && !warning_list.full(); ++i)
    warning_list.push_back(*i);
}
void
AirspaceWarningMonitor::Check()
{
  const auto &calculated = CommonInterface::Calculated();

  if (widget == nullptr && calculated.airspace_warnings.latest == last)
    return;

  /* there's a new airspace warning */

  last = calculated.airspace_warnings.latest;

  auto *airspace_warnings = GetAirspaceWarnings();
  if (airspace_warnings == nullptr) {
    HideWidget();
    return;
  }

  if (!HasPointer()) {
    /* "classic" list-only view for devices without touch screen */

    if (dlgAirspaceWarningVisible())
      /* already visible */
      return;

    // un-blank the display, play a sound
    ResetUserIdle();
    PlayResource(_T("IDR_WAV_BEEPBWEEP"));

    // show airspace warnings dialog
    if (CommonInterface::GetUISettings().enable_airspace_warning_dialog)
      dlgAirspaceWarningsShowModal(*airspace_warnings, true);
    return;
  }

  const AbstractAirspace *airspace = nullptr;
  AirspaceWarning::State state;
  AirspaceInterceptSolution solution;

  {
    const ProtectedAirspaceWarningManager::Lease lease(*airspace_warnings);
    auto w = lease->begin();
    if (w != lease->end() && w->IsAckExpired()) {
      airspace = &w->GetAirspace();
      state = w->GetWarningState();
      solution = w->GetSolution();
    }
  }

  if (airspace == nullptr) {
    HideWidget();
    return;
  }

  if (CommonInterface::GetUISettings().enable_airspace_warning_dialog) {
    /* show airspace warning */
    if (widget != nullptr) {
      if (widget->Update(*airspace, state, solution))
        return;

      HideWidget();
    }

    widget = new AirspaceWarningWidget(*this, *airspace_warnings,
                                       *airspace, state, solution);
    PageActions::SetCustomBottom(widget);
  }

  // un-blank the display, play a sound
  ResetUserIdle();
  PlayResource(_T("IDR_WAV_BEEPBWEEP"));
}