876 /** Start/Stop a ship.

   877  * @param tile unused

   878  * @param flags type of operation

   879  * @param p1 ship ID to start/stop

   880  * @param p2 unused

   881  */

   882 CommandCost CmdStartStopShip(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)

   883 {

   884 	if (!IsValidVehicleID(p1)) return CMD_ERROR;

   885 

   886 	Vehicle *v = GetVehicle(p1);

   887 

   888 	if (v->type != VEH_SHIP || !CheckOwnership(v->owner)) return CMD_ERROR;

   889 

   890 	/* Check if this ship can be started/stopped. The callback will fail or

   891 	 * return 0xFF if it can. */

   892 	uint16 callback = GetVehicleCallback(CBID_VEHICLE_START_STOP_CHECK, 0, 0, v->engine_type, v);

   893 	if (callback != CALLBACK_FAILED && GB(callback, 0, 8) != 0xFF) {

   894 		StringID error = GetGRFStringID(GetEngineGRFID(v->engine_type), 0xD000 + callback);

   895 		return_cmd_error(error);

   896 	}

   897 

   898 	if (flags & DC_EXEC) {

   899 		if (v->IsStoppedInDepot()) {

   900 			DeleteVehicleNews(p1, STR_981C_SHIP_IS_WAITING_IN_DEPOT);

   901 		}

   902 

   903 		v->vehstatus ^= VS_STOPPED;

   904 		v->cur_speed = 0;

   905 		InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, VVW_WIDGET_START_STOP_VEH);

   906 		InvalidateWindow(WC_VEHICLE_DEPOT, v->tile);

   907 		InvalidateWindowClasses(WC_SHIPS_LIST);

   908 	}

   909 

   910 	return CommandCost();

   911 }

   912