freebsd-src/lib/libcurses/tscroll.c
1994-09-24 14:16:04 +00:00

143 lines
3.8 KiB
C

/*-
* Copyright (c) 1992, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
*/
#ifndef lint
static char sccsid[] = "@(#)tscroll.c 8.4 (Berkeley) 7/27/94";
#endif /* not lint */
#include "curses.h"
#define MAXRETURNSIZE 64
/*
* Routine to perform scrolling. Derived from tgoto.c in tercamp(3)
* library. Cap is a string containing printf type escapes to allow
* scrolling. The following escapes are defined for substituting n:
*
* %d as in printf
* %2 like %2d
* %3 like %3d
* %. gives %c hacking special case characters
* %+x like %c but adding x first
*
* The codes below affect the state but don't use up a value.
*
* %>xy if value > x add y
* %i increments n
* %% gives %
* %B BCD (2 decimal digits encoded in one byte)
* %D Delta Data (backwards bcd)
*
* all other characters are ``self-inserting''.
*/
char *
__tscroll(cap, n1, n2)
const char *cap;
int n1, n2;
{
static char result[MAXRETURNSIZE];
int c, n, increment = 0;
char *dp;
if (cap == NULL)
goto err;
for (n = n1, dp = result; (c = *cap++) != '\0';) {
if (c != '%') {
*dp++ = c;
continue;
}
switch (c = *cap++) {
case 'n':
n ^= 0140;
continue;
case 'd':
if (n < 10)
goto one;
if (n < 100)
goto two;
/* FALLTHROUGH */
case '3':
*dp++ = (n / 100) | '0';
n %= 100;
/* FALLTHROUGH */
case '2':
two: *dp++ = n / 10 | '0';
one: *dp++ = n % 10 | '0';
n = n2;
if (increment)
n++;
continue;
case '>':
if (n > *cap++)
n += *cap++;
else
cap++;
continue;
case '+':
n += *cap++;
/* FALLTHROUGH */
case '.':
*dp++ = n;
continue;
case 'i':
increment = 1;
n++;
continue;
case '%':
*dp++ = c;
continue;
case 'B':
n = (n / 10 << 4) + n % 10;
continue;
case 'D':
n = n - 2 * (n % 16);
continue;
/*
* XXX
* System V terminfo files have lots of extra gunk.
* The only one we've seen in scrolling strings is
* %pN, and it seems to work okay if we ignore it.
*/
case 'p':
++cap;
continue;
default:
goto err;
}
}
*dp = '\0';
return (result);
err: return("curses: __tscroll failed");
}