Usenet 1994 October/usenetsourcesnewsgroupsinfomagicoctober1994disk2.iso/unix/volume3/libc_term/get_float.c

C/C++ Source or Header | 1986-11-30 | 4.4 KB | 233 lines

#include <stdio.h>
#include <ctype.h>
#include <curses.h>
#include "c_term.h"

float get_float(Default, field_width, places)
float Default;
int field_width, places;

/*
 ---------------------------------------------------------------------------

   Last revision -
    6 January 1985 - GWS
    Make it use curses

    16 November 1984 - GWS
    Ignore XON, XOFF

     11 April 1984 - GWS


   NAME
     get_float - "crash-proof" float from keyboard routine

   SYNOPSIS
    float get_float(Default, field_width, places)
    float Default;
    int field_width, places;

   DESCRIPTION
    On a good day this routine will get a real value from the
    keyboard and return it safely.  The terminal is placed in raw
    mode and most non-digit values are beeped at and discarded.  Entry
    is terminated by filling the field or by CR.  CR as first character
    assumes Default.  ^X restarts.

   SEE ALSO


   DIAGNOSTICS
    none - cannot fail :-)

   BUGS
    Doesn't check for silly things like Default too big to fit in
    field_width, etc.  Watch out for that minus sign!!

    Exponential notation is not supported.

    This version does not let you erase over the decimal point if
    the integer part of the field is already full.  This is not a
    terrible hardship because you are free to ^X and start over,
    but it really should be fixed.

   AUTHOR
     George W. Sherouse
     9 April 1984

 ---------------------------------------------------------------------------
*/

{
    int c;
    float val;
    int loop;
    char line_buff[20];
    char Format[80];
    char pad;
    int point, frac_count;
    int count;
    int int_part;
    int    where_x,
        where_y,
        x,
        y;

    void f_clean_up();

    pad = ' ';
    point = 0;
    frac_count = 0 ;

    getyx(stdscr, where_y, where_x);
    standout();

    for (loop = 0; loop < field_width; loop++)
        printw(" ");

    move(where_y, where_x);
    refresh();

    sprintf(Format, "%%%d.%df", field_width, places);
    printw(Format, Default);
    move(where_y, where_x);
    refresh();
    for (loop = 0; loop <= field_width; loop++)
        line_buff[loop] = 0;

    count = 0;
    int_part = field_width - places - 1;
    while (1)
    {
        if (!point && count == int_part)
        {
        printw(".");
        line_buff[count++] = '.';
        point++;
        continue;
        }
        refresh();

        c = (getch() & 0x7f);
        switch(c)
        {
#ifdef ABORT_CHAR
        case ABORT_CHAR:
        clear();
        standend();
        mvprintw(0, 0, "Program aborted at your request...");
        move(LINES -1 , 0);
        refresh();
        endwin();
        exit(1);
        break;
#endif ABORT_CHAR

        case '\r':
        if (count && line_buff[count - 1] != '-')
        {
            sscanf(line_buff, "%f", &val);
            f_clean_up(where_y, where_x, Format, val);
            return(val);
        }
        else
        {
            f_clean_up(where_y, where_x, Format, Default);
            return(Default);
        }
        break;
        case '\030':
        move(where_y, where_x);
        for (loop = 0; loop < field_width; loop++)
            line_buff[loop] = 0;
        count = frac_count = point = 0;
        printw(Format, Default);
        move(where_y, where_x);
        break;
        case '.':
        if (!point)
        {
            if (!count)
            {
            for (loop = 0; loop < field_width; loop++)
                printw("%c", pad);
            move(where_y, where_x);
            for (loop = 0; loop < field_width; loop++)
                line_buff[loop] = 0;
            }
            printw(".");
            line_buff[count++] = '.';
            point++;
            break;
        }
        case '\021':
        case '\023':
        break;
        default:
        if (c == erase_char && count)
        {
            getyx(stdscr, y, x);
            move(y, x - 1);
            printw("%c", pad);
            move(y, x - 1);
            if (point)
            {
            if (frac_count)
                frac_count--;
            else
                point--;
            }
            line_buff[--count] = 0;
            break;
        }

        if (!count && c == '-')
        {
            for (loop = 0; loop < field_width; loop++)
            printw("%c", pad);
            move(where_y, where_x);
            for (loop = 0; loop < field_width; loop++)
                line_buff[loop] = 0;

            line_buff[count++] = (char) c;
            printw("-");
            break;
        }

        if (isdigit(c) && count < field_width && frac_count < places)
        {
            if (!count)
            {
            for (loop = 0; loop < field_width; loop++)
                printw("%c", pad);
            move(where_y, where_x);
            for (loop = 0; loop < field_width; loop++)
                line_buff[loop] = 0;
            }
            printw("%c", c);
            line_buff[count++] = (char) c;
            if (point)
            frac_count++;
        }
        else
            fprintf(stderr, "%c", '\007');
        }
    }
}

void f_clean_up(where_y, where_x, Format, val)
int where_y, where_x;
char *Format;
float val;

{
    int loop;

    standend();
    move(where_y, where_x);
    printw(Format, val);

    refresh();
}