long.cpp

GPS的协议为NMEA0183

#include "nmea0183.h"
#pragma hdrstop

/*
** Author: Samuel R. Blackburn
** CI$: 76300,326
** Internet: [e-mail]
**
** You can use it any way you like.
*/

IMPLEMENT_DYNAMIC( LONGITUDE, CObject )

LONGITUDE::LONGITUDE()
{
   Empty();
}

LONGITUDE::~LONGITUDE()
{
   Empty();
}

void LONGITUDE::Empty( void )
{
   ASSERT_VALID( this );

   Longitude = 0.0;
   Easting   = EW_Unknown;
}

BOOL LONGITUDE::IsDataValid( void )
{
   if ( Easting != East && Easting != West )
   {
      return( FALSE );
   }

   return( TRUE );
}

void LONGITUDE::Parse( int position_field_number, int east_or_west_field_number, const SENTENCE& sentence )
{
   ASSERT_VALID( this );

   Set( sentence.Double( position_field_number ), sentence.Field( east_or_west_field_number ) );
}

void LONGITUDE::Set( double position, const char *east_or_west )
{
   ASSERT_VALID( this );
   ASSERT( east_or_west != NULL );

   Longitude = position;

   if ( east_or_west[ 0 ] == 'E' )
   {
      Easting = East;
   }
   else if ( east_or_west[ 0 ] == 'W' )
   {
      Easting = West;
   }
   else
   {
      Easting = EW_Unknown;
   }
}

void LONGITUDE::Write( SENTENCE& sentence )
{
   ASSERT_VALID( this );

   char temp_string[ 80 ];

   sprintf( temp_string, "%.f,", Longitude );
   sentence += temp_string;
   
   if ( Easting == East )
   {
      sentence += "E";
   }
   else if ( Easting == West )
   {
      sentence += "W";
   }
   else
   {
      /*
      ** Add Nothing
      */
   }
}

const LONGITUDE& LONGITUDE::operator = ( const LONGITUDE& source )
{
   ASSERT_VALID( this );

   Longitude = source.Longitude;
   Easting   = source.Easting;

   return( *this );
}