C/C++ Users Group Library 1996 July/C-C++ Users Group Library July 1996.iso/vol_100/111_01/senter.c

Text File | 1985-08-19 | 5KB | 242 lines

/*
HEADER:        ;
TITLE:        Screen entry;
VERSION:    1.0;

DESCRIPTION:    "General screen oriented input/output module.
        This is a component of the diskette sector editor,
        SE.C, but may be useful in other C programs.";

KEYWORDS:    Editor, screen;
SYSTEM:        CP/M-80, V2.2;
FILENAME:    SENTER.C;
SEE-ALSO:    SE.C, SE.DOC;
AUTHORS:    Jan Larsson;
COMPILERS:    BDS C, v1.43 and 1.5a;
*/
/***********************************************************

Version 1.0, 1981:
    Jan Larsson, Kosterv. 12, S-181 35  Lidingo, SWEDEN

************************************************************/

#include <bdscio.h>

#define LCHR '_'
#define ECHR ' '
#define BS 0x08
#define ESC 0x1B

/* Raw character output routine */

co( c )
char c ;
{
    bdos( 6, c );
    if(c == 0x0a)bdos( 6, 0x0d );
}


/* Raw character input routine */

ci(){
    char c ;

    while((c = bdos( 6, 0xff )) == 0);
    if(c == 0x03)stop();
    return( c );
}


/* tplot plots a text at the cursor adress given */

tplot( x, y, text )
char x, y, *text ;
{
    gotoxy( x, y );
    pl( text );
}


/* print a text at the current position */

pl( text )
char *text ;
{
    while(*text != '\0') co( *text++ );
}





bit( c, number )
char c, number ;
{
    return(((c >> number) & 0x01));
}




/*
    ENTER() is a general input routine for CRT terminals with cursor
    adressing. It is called with six parameters (described below) and
    returns TRUE if any characters were input, else FALSE is returned.
    A special case occurs if the ESCAPE key was depressed, if so the
    function will exit immediately and return ESCAPE.

    Call parameters:

        retval = enter( x, y, text, len, inbuf, mode );

        x     is the column on the screen

        y    is the row on the screen (0 - 23)

        text    a pointer to the text printed before input

        len    is the maximum number of bytes allowed as input

        inbuf   a pointer to the buffer where input will be copied

        mode    a byte which controls the functioning of enter(),
                bit 0 :  only numerical input accepted
                bit 1 :  upper case conversion
                bit 2 :  wait for input
                bit 3 :  print contents of inbuf first
                bit 4 :  print contents of text
                bit 5 :  clear inbuf before inbuf, after bit 3
                bit 6 :  print 'mark' line on screen
                bit 7 :  not implemented yet


            (c) 1981 Jan Larsson, Occam Software
*/


char enter( x, y, text, len, inbuf, mode )
char x, y, *text, len, *inbuf, mode ;
{
    int z ;
    char buf[255], x2, y2, numerical, upper, print, input, ledtext ;
    char nolla, wrap, n, *p, c, points ;

    numerical = bit( mode, 0 );
    upper     = bit( mode, 1 );
    input     = bit( mode, 2 );
    print     = bit( mode, 3 );
    ledtext   = bit( mode, 4 );
    nolla      = bit( mode, 5 );
    points    = bit( mode, 6 );

    y2 = y ; x2 = x + strlen( text );

    if( ledtext )tplot( x, y, text );

    if( print ){
        tplot( x2, y2, inbuf );
        if( points ){
            n = len - strlen( inbuf );
            while(n-- > 0)co(LCHR);
            co( ECHR );
            }
        }
    else if( points ){
        gotoxy( x2, y2 );
        n = len ;
        while(n-- > 0)co( LCHR );
        co( ECHR );
        }

    if( nolla )*inbuf = '\0' ;

    if( ! input )return( FALSE );

    gotoxy( x2, y2 ); bell() ; c = '\0' ;
    p = buf ; z = 0 ; wrap = FALSE ;

    while( ! eoi( c ) ){
        if( numerical )while( nodigit((c = ci())));
        else while( unacceptable((c = ci())));
        if(c == ESC)return( ESC );
        if((p - buf) >= len && c != BS && ! eoi( c )){
             wrap = TRUE ; gotoxy( x2, y2 ); }
        if(c == BS && p == buf)bell();
        else if(c == BS){
            z-- ; p-- ;
            co( BS ) ; co( LCHR ) ; co( BS ) ;
            }
        else if( ! eoi( c ) ){
            c = upper ? toupper( c ) : c ;
            if( wrap ){
                wrap = FALSE ;
                n = len ;
                bell() ;
                while(n-- > 0)co( LCHR );
                co( ECHR );
                gotoxy( x2, y2 );
                z = 0 ; p = buf ;
                }
            *p++ = c ;
            z++ ;
            co( c );
            }
        }
    *p = '\0' ;
    p-- ;
    if(z == 0)return( FALSE );
    while(*p == ' '){ co( BS ) ; co( LCHR ) ; co( BS ); p-- ; }
    p++ ;
    *p = '\0' ;
    strcpy( inbuf, buf );
    return( TRUE );
}



bell(){ co( 7 ); }


/* eoi() returns TRUE when a terminating character has been typed */

char eoi( c )
char c ;
{
    switch ( c ) {

        case 0x0d :
        case 0x0a : return( TRUE ) ; break ;

        default   : return( FALSE ) ;
        }
}




/* nodigit() returns true if the character is not a digit */

char nodigit( c )
char c ;
{
    if((c >= '0' && c <= '9') || c == BS || c == ESC || eoi( c ))
                            return( FALSE );
    else return( TRUE );
}


/* unacceptable() returns TRUE if c is control character */

char unacceptable( c )
char c ;
{
    if((c >= ' ' && c < 0x7f) || eoi( c ) || c == BS || c == ESC)
                            return( FALSE );
    else return( TRUE );
}