Method SelectFirstAvailableAirport

src/airport_gui.cpp:541–567

* Select the first available airport. * @param change_class If true, change the class if no airport in the current * class is available. */

	 *   class is available.
	 */
	void SelectFirstAvailableAirport(bool change_class)
	{
		/* First try to select an airport in the selected class. */
		AirportClass *sel_apclass = AirportClass::Get(_selected_airport_class);
		for (const AirportSpec *as : sel_apclass->Specs()) {
			if (as->IsAvailable()) {
				this->SelectOtherAirport(as->index);
				return;
			}
		}
		if (change_class) {
			/* If that fails, select the first available airport
			 * from the first class where airports are available. */
			for (const auto &cls : AirportClass::Classes()) {
				for (const auto &as : cls.Specs()) {
					if (as->IsAvailable()) {
						_selected_airport_class = cls.Index();
						this->vscroll->SetCount(cls.GetSpecCount());
						this->SelectOtherAirport(as->index);
						return;
					}
				}
			}
		}
		/* If all airports are unavailable, select nothing. */
		this->SelectOtherAirport(-1);
	}

	void OnDropdownSelect(WidgetID widget, int index, int) override
	{