gxa.cpp

来自「提取各种NEMA0183格式数据的类编程。」· C++ 代码 · 共 140 行

/*
** Author: Samuel R. Blackburn
** Internet: [e-mail]
**
** Copyright, 1996-2005, Samuel R. Blackburn
**
** "You can get credit for something or get it done, but not both."
** Dr. Richard Garwin
**
** BSD License follows.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
**
** Redistributions of source code must retain the above copyright notice,
** this list of conditions and the following disclaimer. Redistributions
** in binary form must reproduce the above copyright notice, this list
** of conditions and the following disclaimer in the documentation and/or
** other materials provided with the distribution. Neither the name of
** the WFC nor the names of its contributors may be used to endorse or
** promote products derived from this software without specific prior
** written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
**
** $Workfile: gxa.cpp $
** $Revision: 5 $
** $Modtime: 10/10/98 2:44p $
*/

#include "nmea0183.h"
#pragma hdrstop

#if defined( _DEBUG ) && defined( _INC_CRTDBG )
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#define new DEBUG_NEW
#endif // _DEBUG

GXA::GXA()
{
   Mnemonic = TEXT( "GXA" );
   Empty();
}

GXA::~GXA()
{
   Mnemonic.Empty();
   Empty();
}

void GXA::Empty( void )
{
   UTCTime.Empty();
   Position.Empty();
   WaypointID.Empty();
   SatelliteNumber = 0;
}

BOOL GXA::Parse( const SENTENCE& sentence )
{
   /*
   ** GXA - TRANSIT Position - Latitude/Longitude
   ** Location and time of TRANSIT fix at waypoint
   **
   **        1         2       3 4        5 6    7 8
   **        |         |       | |        | |    | |
   ** $--GXA,hhmmss.ss,llll.ll,a,yyyyy.yy,a,c--c,X*hh<CR><LF>
   **
   ** 1) UTC of position fix
   ** 2) Latitude
   ** 3) East or West
   ** 4) Longitude
   ** 5) North or South
   ** 6) Waypoint ID
   ** 7) Satelite number
   ** 8) Checksum
   */

   /*
   ** First we check the checksum...
   */

   const NMEA0183_BOOLEAN checksum_is_bad = sentence.IsChecksumBad();

   if ( checksum_is_bad == True )
   {
      InvalidChecksum();
      return( FALSE );
   } 

   UTCTime         = sentence.Field( 1 );
   Time            = sentence.Time( 1 );
   Position.Parse( 2, 3, 4, 5, sentence );
   WaypointID      = sentence.Field( 6 );
   SatelliteNumber = (WORD) sentence.Integer( 7 );

   return( TRUE );
}

BOOL GXA::Write( SENTENCE& sentence )
{
   /*
   ** Let the parent do its thing
   */
   
   RESPONSE::Write( sentence );

   sentence += UTCTime;
   sentence += Position;
   sentence += WaypointID;
   sentence += Hex( SatelliteNumber ); // Thanks to Chuck Shannon, [e-mail]

   sentence.Finish();

   return( TRUE );
}

const GXA& GXA::operator = ( const GXA& source )
{
   UTCTime         = source.UTCTime;
   Time            = source.Time;
   Position        = source.Position;
   WaypointID      = source.WaypointID;
   SatelliteNumber = source.SatelliteNumber;

   return( *this );
}