gll.cpp

来自「提取各种NEMA0183格式数据的类编程。」· C++ 代码 · 共 163 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: gll.cpp $
** $Revision: 6 $
** $Modtime: 10/12/98 6:39a $
*/

#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

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

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

void GLL::Empty( void )
{
   Position.Empty();
   UTCTime.Empty();
   IsDataValid = NMEA_Unknown;
   FAAMode     = FAAModeUnknown;
}

BOOL GLL::Parse( const SENTENCE& sentence )
{
   /*
   ** GLL - Geographic Position - Latitude/Longitude
   ** Latitude, N/S, Longitude, E/W, UTC, Status
   **
   **        1       2 3        4 5         6 7
   **        |       | |        | |         | |
   ** $--GLL,llll.ll,a,yyyyy.yy,a,hhmmss.ss,A*hh<CR><LF>
   **
   ** Field Number: 
   **  1) Latitude
   **  2) N or S (North or South)
   **  3) Longitude
   **  4) E or W (East or West)
   **  5) Universal Time Coordinated (UTC)
   **  6) Status A - Data Valid, V - Data Invalid
   **  7) Checksum
   */

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

   const NMEA0183_BOOLEAN checksum_is_bad = sentence.IsChecksumBad();

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

   Position.Parse( 1, 2, 3, 4, sentence );
   UTCTime     = sentence.Field( 5 );
   Time        = sentence.Time( 5 );
   IsDataValid = sentence.Boolean( 6 );

   const int checksum_field_number = sentence.ChecksumFieldNumber();

   if ( checksum_field_number == 8 )
   {
      FAAMode = sentence.FAAMode( 7 );
   }
   else
   {
      FAAMode = FAAModeUnknown;
   }

   return( TRUE );
}

CString GLL::ToText( void ) const
{
   CString return_string;

   return_string.Empty();

   return_string = TEXT( "At " );
   return_string += Time.Format( TEXT( "%I:%M.%S %p" ) );
   return_string += TEXT( " UTC, you were at " );
   return_string += Position.ToText();
   return_string += TEXT( "." );

   return( return_string );
}

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

   sentence += Position;
   sentence += UTCTime;
   sentence += IsDataValid;

   sentence.Finish();

   return( TRUE );
}

const GLL& GLL::operator = ( const GLL& source )
{
   Position    = source.Position;
   UTCTime     = source.UTCTime;
   Time        = source.Time;
   IsDataValid = source.IsDataValid;

   return( *this );
}