1 files changed, 305 insertions, 0 deletions
diff --git a/contrib/nvi/vi/vs_relative.c b/contrib/nvi/vi/vs_relative.c
new file mode 100644
index 0000000..c92c10c
--- /dev/null
+++ b/contrib/nvi/vi/vs_relative.c
@@ -0,0 +1,305 @@
+/*-
+ * Copyright (c) 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1993, 1994, 1995, 1996
+ *	Keith Bostic.  All rights reserved.
+ *
+ * See the LICENSE file for redistribution information.
+ */
+
+#include "config.h"
+
+#ifndef lint
+static const char sccsid[] = "@(#)vs_relative.c	10.11 (Berkeley) 5/13/96";
+#endif /* not lint */
+
+#include <sys/types.h>
+#include <sys/queue.h>
+#include <sys/time.h>
+
+#include <bitstring.h>
+#include <limits.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "../common/common.h"
+#include "vi.h"
+
+/*
+ * vs_column --
+ *	Return the logical column of the cursor in the line.
+ *
+ * PUBLIC: int vs_column __P((SCR *, size_t *));
+ */
+int
+vs_column(sp, colp)
+	SCR *sp;
+	size_t *colp;
+{
+	VI_PRIVATE *vip;
+
+	vip = VIP(sp);
+
+	*colp = (O_ISSET(sp, O_LEFTRIGHT) ?
+	    vip->sc_smap->coff : (vip->sc_smap->soff - 1) * sp->cols) +
+	    vip->sc_col - (O_ISSET(sp, O_NUMBER) ? O_NUMBER_LENGTH : 0);
+	return (0);
+}
+
+/*
+ * vs_screens --
+ *	Return the screens necessary to display the line, or if specified,
+ *	the physical character column within the line, including space
+ *	required for the O_NUMBER and O_LIST options.
+ *
+ * PUBLIC: size_t vs_screens __P((SCR *, recno_t, size_t *));
+ */
+size_t
+vs_screens(sp, lno, cnop)
+	SCR *sp;
+	recno_t lno;
+	size_t *cnop;
+{
+	size_t cols, screens;
+
+	/* Left-right screens are simple, it's always 1. */
+	if (O_ISSET(sp, O_LEFTRIGHT))
+		return (1);
+
+	/*
+	 * Check for a cached value.  We maintain a cache because, if the
+	 * line is large, this routine gets called repeatedly.  One other
+	 * hack, lots of time the cursor is on column one, which is an easy
+	 * one.
+	 */
+	if (cnop == NULL) {
+		if (VIP(sp)->ss_lno == lno)
+			return (VIP(sp)->ss_screens);
+	} else if (*cnop == 0)
+		return (1);
+
+	/* Figure out how many columns the line/column needs. */
+	cols = vs_columns(sp, NULL, lno, cnop, NULL);
+
+	screens = (cols / sp->cols + (cols % sp->cols ? 1 : 0));
+	if (screens == 0)
+		screens = 1;
+
+	/* Cache the value. */
+	if (cnop == NULL) {
+		VIP(sp)->ss_lno = lno;
+		VIP(sp)->ss_screens = screens;
+	}
+	return (screens);
+}
+
+/*
+ * vs_columns --
+ *	Return the screen columns necessary to display the line, or,
+ *	if specified, the physical character column within the line.
+ *
+ * PUBLIC: size_t vs_columns __P((SCR *, char *, recno_t, size_t *, size_t *));
+ */
+size_t
+vs_columns(sp, lp, lno, cnop, diffp)
+	SCR *sp;
+	char *lp;
+	recno_t lno;
+	size_t *cnop, *diffp;
+{
+	size_t chlen, cno, curoff, last, len, scno;
+	int ch, leftright, listset;
+	char *p;
+
+	/* Need the line to go any further. */
+	if (lp == NULL) {
+		(void)db_get(sp, lno, 0, &lp, &len);
+		if (len == 0)
+			goto done;
+	}
+
+	/* Missing or empty lines are easy. */
+	if (lp == NULL) {
+done:		if (diffp != NULL)		/* XXX */
+			*diffp = 0;
+		return (0);
+	}
+
+	/* Store away the values of the list and leftright edit options. */
+	listset = O_ISSET(sp, O_LIST);
+	leftright = O_ISSET(sp, O_LEFTRIGHT);
+
+	/*
+	 * Initialize the pointer into the buffer and screen and current
+	 * offsets.
+	 */
+	p = lp;
+	curoff = scno = 0;
+
+	/* Leading number if O_NUMBER option set. */
+	if (O_ISSET(sp, O_NUMBER))
+		scno += O_NUMBER_LENGTH;
+
+	/* Macro to return the display length of any signal character. */
+#define	CHLEN(val) (ch = *(u_char *)p++) == '\t' &&			\
+	    !listset ? TAB_OFF(val) : KEY_LEN(sp, ch);
+
+	/*
+	 * If folding screens (the historic vi screen format), past the end
+	 * of the current screen, and the character was a tab, reset the
+	 * current screen column to 0, and the total screen columns to the
+	 * last column of the screen.  Otherwise, display the rest of the
+	 * character in the next screen.
+	 */
+#define	TAB_RESET {							\
+	curoff += chlen;						\
+	if (!leftright && curoff >= sp->cols)				\
+		if (ch == '\t') {					\
+			curoff = 0;					\
+			scno -= scno % sp->cols;			\
+		} else							\
+			curoff -= sp->cols;				\
+}
+	if (cnop == NULL)
+		while (len--) {
+			chlen = CHLEN(curoff);
+			last = scno;
+			scno += chlen;
+			TAB_RESET;
+		}
+	else
+		for (cno = *cnop;; --cno) {
+			chlen = CHLEN(curoff);
+			last = scno;
+			scno += chlen;
+			TAB_RESET;
+			if (cno == 0)
+				break;
+		}
+
+	/* Add the trailing '$' if the O_LIST option set. */
+	if (listset && cnop == NULL)
+		scno += KEY_LEN(sp, '$');
+
+	/*
+	 * The text input screen code needs to know how much additional
+	 * room the last two characters required, so that it can handle
+	 * tab character displays correctly.
+	 */
+	if (diffp != NULL)
+		*diffp = scno - last;
+	return (scno);
+}
+
+/*
+ * vs_rcm --
+ *	Return the physical column from the line that will display a
+ *	character closest to the currently most attractive character
+ *	position (which is stored as a screen column).
+ *
+ * PUBLIC: size_t vs_rcm __P((SCR *, recno_t, int));
+ */
+size_t
+vs_rcm(sp, lno, islast)
+	SCR *sp;
+	recno_t lno;
+	int islast;
+{
+	size_t len;
+
+	/* Last character is easy, and common. */
+	if (islast) {
+		if (db_get(sp, lno, 0, NULL, &len) || len == 0)
+			return (0);
+		return (len - 1);
+	}
+
+	/* First character is easy, and common. */
+	if (sp->rcm == 0)
+		return (0);
+
+	return (vs_colpos(sp, lno, sp->rcm));
+}
+
+/*
+ * vs_colpos --
+ *	Return the physical column from the line that will display a
+ *	character closest to the specified screen column.
+ *
+ * PUBLIC: size_t vs_colpos __P((SCR *, recno_t, size_t));
+ */
+size_t
+vs_colpos(sp, lno, cno)
+	SCR *sp;
+	recno_t lno;
+	size_t cno;
+{
+	size_t chlen, curoff, len, llen, off, scno;
+	int ch, leftright, listset;
+	char *lp, *p;
+
+	/* Need the line to go any further. */
+	(void)db_get(sp, lno, 0, &lp, &llen);
+
+	/* Missing or empty lines are easy. */
+	if (lp == NULL || llen == 0)
+		return (0);
+
+	/* Store away the values of the list and leftright edit options. */
+	listset = O_ISSET(sp, O_LIST);
+	leftright = O_ISSET(sp, O_LEFTRIGHT);
+
+	/* Discard screen (logical) lines. */
+	off = cno / sp->cols;
+	cno %= sp->cols;
+	for (scno = 0, p = lp, len = llen; off--;) {
+		for (; len && scno < sp->cols; --len)
+			scno += CHLEN(scno);
+
+		/*
+		 * If reached the end of the physical line, return the last
+		 * physical character in the line.
+		 */
+		if (len == 0)
+			return (llen - 1);
+
+		/*
+		 * If folding screens (the historic vi screen format), past
+		 * the end of the current screen, and the character was a tab,
+		 * reset the current screen column to 0.  Otherwise, the rest
+		 * of the character is displayed in the next screen.
+		 */
+		if (leftright && ch == '\t')
+			scno = 0;
+		else
+			scno -= sp->cols;
+	}
+
+	/* Step through the line until reach the right character or EOL. */
+	for (curoff = scno; len--;) {
+		chlen = CHLEN(curoff);
+
+		/*
+		 * If we've reached the specific character, there are three
+		 * cases.
+		 *
+		 * 1: scno == cno, i.e. the current character ends at the
+		 *    screen character we care about.
+		 *	a: off < llen - 1, i.e. not the last character in
+		 *	   the line, return the offset of the next character.
+		 *	b: else return the offset of the last character.
+		 * 2: scno != cno, i.e. this character overruns the character
+		 *    we care about, return the offset of this character.
+		 */
+		if ((scno += chlen) >= cno) {
+			off = p - lp;
+			return (scno == cno ?
+			    (off < llen - 1 ? off : llen - 1) : off - 1);
+		}
+
+		TAB_RESET;
+	}
+
+	/* No such character; return the start of the last character. */
+	return (llen - 1);
+}