void ThermalZonesController::addComponentToZone(model::ThermalZone & zone, Handle & h)
{
  boost::optional<model::ZoneHVACComponent> libraryComp;

  model::Model library = OSAppBase::instance()->currentDocument()->componentLibrary();
  libraryComp = library.getModelObject<model::ZoneHVACComponent>(h);

  if( libraryComp )
  {
    std::vector<model::ModelObject> existingComps;
    existingComps = zone.equipment();

    std::vector<model::ZoneHVACComponent> exisitngHVACComps;

    for( auto it = existingComps.begin();
         it < existingComps.end();
         ++it )
    {
      if( boost::optional<model::ZoneHVACComponent> hvacComp = it->optionalCast<model::ZoneHVACComponent>() )
      {
        exisitngHVACComps.push_back(hvacComp.get());
      }
    }

    if( exisitngHVACComps.size() > 0 )
    {
      QMessageBox message(subTabView());
      
      message.setText("Sorry, only one piece of zone equipment is allowed at this time.");

      message.exec();

      return;
    }
  }

  bool wasSuccessful = false;

  if( libraryComp )
  {
    model::ZoneHVACComponent compClone = libraryComp->clone(model()).cast<model::ZoneHVACComponent>();
  
    bool added = compClone.addToThermalZone(zone);

    if( added )
    {
      wasSuccessful = true;
    }
    else
    {
      compClone.remove();
    }
  }

  if( ! wasSuccessful )
  {
    QMessageBox message(subTabView());
    
    message.setText("The selected component is not allowed at this location.");

    message.exec();
  }
}