user.c

CD_高级PALM编程

/********************************************************************
* FILE:				User.c
*
* DESCRIPTION:	User-level code for the MyDBViewer.c project.
*               This file is the place you put YOUR functions for
*               showing YOUR data in the MyDBViewer test application.
*
* VERSION:		1.0
**********************************************************************/
#include <PalmOS.h>
#include "User.h"

#define userNoTextStr "No text representation is available for this type."

/***********************************************************************
 * FUNCTION:    	UserRecordToText_mpoi
 *
 * DESCRIPTION: 	Converts records to text.  
 *                  This function is for the ppoi type used in Chapter 4.
 *
 * RETURNED:    	pointer to the text representation.  Caller must free.
 ***********************************************************************/
static Char *UserRecordToText_mpoi
(
	MemPtr dataP	// (in) data to be shown
)
{
	Char *resultP;
	int	sz;
	Char *labelP;
	struct mpoi { Int32 top, left; /* label follows */ } *recordP;
	
	recordP = ( struct mpoi *)dataP;
	
	labelP = (Char *)((char *)(dataP)+sizeof( struct mpoi ));
	
	sz = StrLen( labelP ) + 128; // It's just a string!	
	resultP = MemPtrNew( sz * sizeof( Char *)  );

	if ( resultP )
	{
		StrPrintF( resultP, "(%ld, %ld) -", recordP->left, recordP->top );
		StrCat( resultP, labelP );
	}
	return resultP;
}

/***********************************************************************
 * FUNCTION:    	UserRecordToText_text
 *
 * DESCRIPTION: 	Converts records to text.  Copy and mutate this method
 *                  as appropriate for the types you create.
 *
 * RETURNED:    	pointer to the text representation.  Caller must free.
 ***********************************************************************/
static Char *UserRecordToText_text
(
	MemPtr dataP	// (in) data to be shown
)
{
	Char  	*resultP;
	int	sz;
	
	/*
	 * When creating text representations of arbitrary data, StrPrintF
	 * is your friend.  Although this isn't the most efficient 
	 * implementation for the 'text' type (since the data is text anyway!)
	 * we're going to do this this way to show you what we mean.
	 */
	sz = StrLen( (Char *)dataP ) + 1; // It's just a string!
	resultP = MemPtrNew( sz * sizeof( Char *)  );
	if ( resultP )
	{
		StrPrintF( resultP, "%s", dataP );
	}
	return resultP;
}

/***********************************************************************
 * FUNCTION:    	UserRecordToText_noType
 *
 * DESCRIPTION: 	Converts records to text.  Mutate this method
 *                  as appropriate for the no-type databases you create.
 *
 * RETURNED:    	pointer to the text representation.  Caller must free.
 ***********************************************************************/
static Char *UserRecordToText_noType
(
	MemPtr dataP	// (in) data to be shown
)
{
	Char  	*resultP;
	int	sz;
	
	/*
	 * When creating text representations of arbitrary data, StrPrintF
	 * is your friend.  Although this isn't the most efficient 
	 * implementation for the 'text' type (since the data is text anyway!)
	 * we're going to do this this way to show you what we mean.
	 */
	sz = StrLen( (Char *)dataP ) + 1; // It's just a string!
	resultP = MemPtrNew( sz * sizeof( Char *)  );
	if ( resultP )
	{
		StrPrintF( resultP, "%s", dataP );
	}
	return resultP;
}


/***********************************************************************
 * FUNCTION:    	UserRecordToText
 *
 * DESCRIPTION: 	This routine creates a text representation of the
 *                  data of the given PalmDatabaseBuilder type.  It's
 *                  up to YOU to handle types other than 'text'!
 *
 * RETURNED:    	pointer to the text representation.  Caller must free.
 ***********************************************************************/
Char *UserRecordToText
(
	UInt32 type,	// (in) type of data to be shown
	MemPtr dataP	// (in) data to be shown
)
{
	Char *strP;
	
	switch( type )
	{
		case 'text':
			strP = UserRecordToText_text( dataP );
			break;
						
		/*
		 * Your types go here...
		 */		

		case 'mpoi':
			strP = UserRecordToText_mpoi( dataP );
			break;

		case 0:
			strP = UserRecordToText_noType( dataP );
			break;
			
		default:
			strP = MemPtrNew( ( StrLen( userNoTextStr ) + 1 ) * sizeof( Char *) );
			if ( strP )
			{
				StrCopy( strP, userNoTextStr );
			}
	}
	return strP;
}