Ejemplo n.º 1
0
/*
 * vs_scroll --
 *	Scroll the screen for output.
 */
static void
vs_scroll(SCR *sp, int *continuep, sw_t wtype)
{
	GS *gp;
	VI_PRIVATE *vip;

	gp = sp->gp;
	vip = VIP(sp);
	if (!IS_ONELINE(sp)) {
		/*
		 * Scroll the screen.  Instead of scrolling the entire screen,
		 * delete the line above the first line output so preserve the
		 * maximum amount of the screen.
		 */
		(void)gp->scr_move(sp, vip->totalcount <
		    sp->rows ? LASTLINE(sp) - vip->totalcount : 0, 0);
		(void)gp->scr_deleteln(sp);

		/* If there are screens below us, push them back into place. */
		if (sp->q.cqe_next != (void *)&sp->wp->scrq) {
			(void)gp->scr_move(sp, LASTLINE(sp), 0);
			(void)gp->scr_insertln(sp);
		}
	}
	if (wtype == SCROLL_W_QUIT && vip->linecount < sp->t_maxrows)
		return;
	vs_wait(sp, continuep, wtype);
}
Ejemplo n.º 2
0
/*
 * cl_deleteln --
 *	Delete the current line, scrolling all lines below it.
 *
 * PUBLIC: int cl_deleteln __P((SCR *));
 */
int
cl_deleteln(SCR *sp)
{
	CHAR_T ch;
	CL_PRIVATE *clp;
	WINDOW *win;
	size_t col, lno, spcnt, y, x;

	clp = CLP(sp);
	win = CLSP(sp) ? CLSP(sp) : stdscr;

	/*
	 * This clause is required because the curses screen uses reverse
	 * video to delimit split screens.  If the screen does not do this,
	 * this code won't be necessary.
	 *
	 * If the bottom line was in reverse video, rewrite it in normal
	 * video before it's scrolled.
	 *
	 * Check for the existence of a chgat function; XSI requires it, but
	 * historic implementations of System V curses don't.   If it's not
	 * a #define, we'll fall back to doing it by hand, which is slow but
	 * acceptable.
	 *
	 * By hand means walking through the line, retrieving and rewriting
	 * each character.  Curses has no EOL marker, so track strings of
	 * spaces, and copy the trailing spaces only if there's a non-space
	 * character following.
	 */
	if (!F_ISSET(sp, SC_SCR_EXWROTE) && IS_SPLIT(sp)) {
		getyx(win, y, x);
#ifdef mvchgat
		mvwchgat(win, RLNO(sp, LASTLINE(sp)), 0, -1, A_NORMAL, 0, NULL);
#else
		for (lno = RLNO(sp, LASTLINE(sp)), col = spcnt = 0;;) {
			(void)wmove(win, lno, col);
			ch = winch(win);
			if (isblank(ch))
				++spcnt;
			else {
				(void)wmove(win, lno, col - spcnt);
				for (; spcnt > 0; --spcnt)
					(void)waddch(win, ' ');
				(void)waddch(win, ch);
			}
			if (++col >= sp->cols)
				break;
		}
#endif
		(void)wmove(win, y, x);
	}

	/*
	 * The bottom line is expected to be blank after this operation,
	 * and other screens must support that semantic.
	 */
	return (wdeleteln(win) == ERR);
}
Ejemplo n.º 3
0
/*
 * ip_addstr --
 *	Add len bytes from the string at the cursor, advancing the cursor.
 *
 * PUBLIC: int ip_addstr __P((SCR *, const char *, size_t));
 */
int
ip_addstr(SCR *sp, const char *str, size_t len)
{
	IP_BUF ipb;
	IP_PRIVATE *ipp;
	int iv, rval;

	ipp = IPP(sp);

	/*
	 * If ex isn't in control, it's the last line of the screen and
	 * it's a split screen, use inverse video.
	 */
	iv = 0;
	if (!F_ISSET(sp, SC_SCR_EXWROTE) &&
	    ipp->row == LASTLINE(sp) && IS_SPLIT(sp)) {
		iv = 1;
		ip_attr(sp, SA_INVERSE, 1);
	}
	ipb.code = SI_ADDSTR;
	ipb.len1 = len;
	ipb.str1 = str;
	rval = vi_send(ipp->o_fd, "a", &ipb);
	/* XXXX */
	ipp->col += len;

	if (iv)
		ip_attr(sp, SA_INVERSE, 0);
	return (rval);
}
Ejemplo n.º 4
0
/*
 * ip_deleteln --
 *	Delete the current line, scrolling all lines below it.
 *
 * PUBLIC: int ip_deleteln __P((SCR *));
 */
int
ip_deleteln(SCR *sp)
{
	IP_BUF ipb;
	IP_PRIVATE *ipp = IPP(sp);

	/*
	 * This clause is required because the curses screen uses reverse
	 * video to delimit split screens.  If the screen does not do this,
	 * this code won't be necessary.
	 *
	 * If the bottom line was in reverse video, rewrite it in normal
	 * video before it's scrolled.
	 */
	if (!F_ISSET(sp, SC_SCR_EXWROTE) && IS_SPLIT(sp)) {
		ipb.code = SI_REWRITE;
		ipb.val1 = RLNO(sp, LASTLINE(sp));
		if (vi_send(ipp->o_fd, "1", &ipb))
			return (1);
	}

	/*
	 * The bottom line is expected to be blank after this operation,
	 * and other screens must support that semantic.
	 */
	ipb.code = SI_DELETELN;
	return (vi_send(ipp->o_fd, NULL, &ipb));
}
Ejemplo n.º 5
0
static int 
addstr4(SCR *sp, const void *str, size_t len, int wide)
{
	WINDOW *win;
	size_t y, x;
	int iv;

	win = CLSP(sp) ? CLSP(sp) : stdscr;

	/*
	 * If ex isn't in control, it's the last line of the screen and
	 * it's a split screen, use inverse video.
	 */
	iv = 0;
	getyx(win, y, x);
	__USE(x);
	if (!F_ISSET(sp, SC_SCR_EXWROTE) &&
	    y == RLNO(sp, LASTLINE(sp)) && IS_SPLIT(sp)) {
		iv = 1;
		(void)wstandout(win);
	}

#ifdef USE_WIDECHAR
	if (wide) {
	    if (waddnwstr(win, str, len) == ERR)
		return (1);
	} else 
#endif
	    if (waddnstr(win, str, len) == ERR)
		    return (1);

	if (iv)
		(void)wstandend(win);
	return (0);
}
Ejemplo n.º 6
0
/*
 * vs_update --
 *	Update a command.
 *
 * PUBLIC: void vs_update __P((SCR *, const char *, const CHAR_T *));
 */
void
vs_update(SCR *sp, const char *m1, const CHAR_T *m2)
{
	GS *gp;
	size_t len, mlen, oldx, oldy;
	const char *np;
	size_t nlen;

	gp = sp->gp;

	/*
	 * This routine displays a message on the bottom line of the screen,
	 * without updating any of the command structures that would keep it
	 * there for any period of time, i.e. it is overwritten immediately.
	 *
	 * It's used by the ex read and ! commands when the user's command is
	 * expanded, and by the ex substitution confirmation prompt.
	 */
	if (F_ISSET(sp, SC_SCR_EXWROTE)) {
		if (m2 != NULL)
			INT2CHAR(sp, m2, STRLEN(m2) + 1, np, nlen);
		(void)ex_printf(sp,
		    "%s%s\n", m1 == NULL? "" : m1, m2 == NULL ? "" : np);
		(void)ex_fflush(sp);
	}

	/*
	 * Save the cursor position, the substitute-with-confirmation code
	 * will have already set it correctly.
	 */
	(void)gp->scr_cursor(sp, &oldy, &oldx);

	/* Clear the bottom line. */
	(void)gp->scr_move(sp, LASTLINE(sp), 0);
	(void)gp->scr_clrtoeol(sp);

	/*
	 * XXX
	 * Don't let long file names screw up the screen.
	 */
	if (m1 != NULL) {
		mlen = len = strlen(m1);
		if (len > sp->cols - 2)
			mlen = len = sp->cols - 2;
		(void)gp->scr_addstr(sp, m1, mlen);
	} else
		len = 0;
	if (m2 != NULL) {
		mlen = STRLEN(m2);
		if (len + mlen > sp->cols - 2)
			mlen = (sp->cols - 2) - len;
		(void)gp->scr_waddstr(sp, m2, mlen);
	}

	(void)gp->scr_move(sp, oldy, oldx);
	(void)gp->scr_refresh(sp, 0);
}
Ejemplo n.º 7
0
/*
 * v_c_settop --
 *	Scrollbar position.
 */
static int
v_c_settop(SCR *sp, VICMD *vp)
{
	SMAP *smp;
	size_t x = 0, y = LASTLINE(sp); /* Future: change to -1 to not
					 * display the cursor
					 */
	size_t tx, ty = -1;

	/*
	 * We want to scroll the screen, without changing the cursor position.
	 * So, we fill the screen map and then flush it to the screen.  Then,
	 * set the VIP_S_REFRESH flag so the main vi loop doesn't update the
	 * screen.  When the next real command happens, the refresh code will
	 * notice that the screen map is way wrong and fix it.
	 *
	 * XXX
	 * There may be a serious performance problem here -- we're doing no
	 * optimization whatsoever, which means that we're copying the entire
	 * screen out to the X11 screen code on each change.
	 */
	if (vs_sm_fill(sp, vp->ev.e_lno, P_TOP))
		return (1);
	for (smp = HMAP; smp <= TMAP; ++smp) {
                SMAP_FLUSH(smp);
		if (vs_line(sp, smp, &ty, &tx))
			return (1);
		if (ty != (size_t)-1) {
			y = ty;
			x = tx;
		}
        }
	(void)sp->gp->scr_move(sp, y, x);

	F_SET(VIP(sp), VIP_S_REFRESH);

	return (sp->gp->scr_refresh(sp, 0));
}
Ejemplo n.º 8
0
/*
 * vs_wait --
 *	Prompt the user to continue.
 */
static void
vs_wait(SCR *sp, int *continuep, sw_t wtype)
{
	EVENT ev;
	VI_PRIVATE *vip;
	const char *p;
	GS *gp;
	size_t len;

	gp = sp->gp;
	vip = VIP(sp);

	(void)gp->scr_move(sp, LASTLINE(sp), 0);
	if (IS_ONELINE(sp))
		p = msg_cmsg(sp, CMSG_CONT_S, &len);
	else
		switch (wtype) {
		case SCROLL_W_QUIT:
			p = msg_cmsg(sp, CMSG_CONT_Q, &len);
			break;
		case SCROLL_W_EX:
			p = msg_cmsg(sp, CMSG_CONT_EX, &len);
			break;
		case SCROLL_W:
			p = msg_cmsg(sp, CMSG_CONT, &len);
			break;
		default:
			abort();
			/* NOTREACHED */
		}
	(void)gp->scr_addstr(sp, p, len);

	++vip->totalcount;
	vip->linecount = 0;

	(void)gp->scr_clrtoeol(sp);
	(void)gp->scr_refresh(sp, 0);

	/* Get a single character from the terminal. */
	if (continuep != NULL)
		*continuep = 0;
	for (;;) {
		if (v_event_get(sp, &ev, 0, 0))
			return;
		if (ev.e_event == E_CHARACTER)
			break;
		if (ev.e_event == E_INTERRUPT) {
			ev.e_c = CH_QUIT;
			F_SET(gp, G_INTERRUPTED);
			break;
		}
		(void)gp->scr_bell(sp);
	}
	switch (wtype) {
	case SCROLL_W_QUIT:
		if (ev.e_c == CH_QUIT)
			F_SET(gp, G_INTERRUPTED);
		break;
	case SCROLL_W_EX:
		if (ev.e_c == ':' && continuep != NULL)
			*continuep = 1;
		break;
	case SCROLL_W:
		break;
	}
}
Ejemplo n.º 9
0
/*
 * vs_busy --
 *	Display, update or clear a busy message.
 *
 * This routine is the default editor interface for vi busy messages.  It
 * implements a standard strategy of stealing lines from the bottom of the
 * vi text screen.  Screens using an alternate method of displaying busy
 * messages, e.g. X11 clock icons, should set their scr_busy function to the
 * correct function before calling the main editor routine.
 *
 * PUBLIC: void vs_busy __P((SCR *, const char *, busy_t));
 */
void
vs_busy(SCR *sp, const char *msg, busy_t btype)
{
	GS *gp;
	VI_PRIVATE *vip;
	static const char flagc[] = "|/-\\";
	struct timeval tv;
	size_t len, notused;
	const char *p;

	/* Ex doesn't display busy messages. */
	if (F_ISSET(sp, SC_EX | SC_SCR_EXWROTE))
		return;

	gp = sp->gp;
	vip = VIP(sp);

	/*
	 * Most of this routine is to deal with the screen sharing real estate
	 * between the normal edit messages and the busy messages.  Logically,
	 * all that's needed is something that puts up a message, periodically
	 * updates it, and then goes away.
	 */
	switch (btype) {
	case BUSY_ON:
		++vip->busy_ref;
		if (vip->totalcount != 0 || vip->busy_ref != 1)
			break;

		/* Initialize state for updates. */
		vip->busy_ch = 0;
		(void)gettimeofday(&vip->busy_tv, NULL);

		/* Save the current cursor. */
		(void)gp->scr_cursor(sp, &vip->busy_oldy, &vip->busy_oldx);

		/* Display the busy message. */
		p = msg_cat(sp, msg, &len);
		(void)gp->scr_move(sp, LASTLINE(sp), 0);
		(void)gp->scr_addstr(sp, p, len);
		(void)gp->scr_cursor(sp, &notused, &vip->busy_fx);
		(void)gp->scr_clrtoeol(sp);
		(void)gp->scr_move(sp, LASTLINE(sp), vip->busy_fx);
		break;
	case BUSY_OFF:
		if (vip->busy_ref == 0)
			break;
		--vip->busy_ref;

		/*
		 * If the line isn't in use for another purpose, clear it.
		 * Always return to the original position.
		 */
		if (vip->totalcount == 0 && vip->busy_ref == 0) {
			(void)gp->scr_move(sp, LASTLINE(sp), 0);
			(void)gp->scr_clrtoeol(sp);
		}
		(void)gp->scr_move(sp, vip->busy_oldy, vip->busy_oldx);
		break;
	case BUSY_UPDATE:
		if (vip->totalcount != 0 || vip->busy_ref == 0)
			break;

		/* Update no more than every 1/8 of a second. */
		(void)gettimeofday(&tv, NULL);
		if (((tv.tv_sec - vip->busy_tv.tv_sec) * 1000000 +
		    (tv.tv_usec - vip->busy_tv.tv_usec)) < 125000)
			return;
		vip->busy_tv = tv;

		/* Display the update. */
		if (vip->busy_ch == sizeof(flagc) - 1)
			vip->busy_ch = 0;
		(void)gp->scr_move(sp, LASTLINE(sp), vip->busy_fx);
		(void)gp->scr_addstr(sp, flagc + vip->busy_ch++, 1);
		(void)gp->scr_move(sp, LASTLINE(sp), vip->busy_fx);
		break;
	}
	(void)gp->scr_refresh(sp, 0);
}
Ejemplo n.º 10
0
/*
 * vs_output --
 *	Output the text to the screen.
 */
static void
vs_output(SCR *sp, mtype_t mtype, const char *line, int llen)
{
	unsigned char *kp;
	GS *gp;
	VI_PRIVATE *vip;
	size_t chlen, notused;
	int ch, len, rlen, tlen;
	const char *p, *t;
	char *cbp, *ecbp, cbuf[128];

	gp = sp->gp;
	vip = VIP(sp);
	for (p = line, rlen = llen; llen > 0;) {
		/* Get the next physical line. */
		if ((p = memchr(line, '\n', llen)) == NULL)
			len = llen;
		else
			len = p - line;

		/*
		 * The max is sp->cols characters, and we may have already
		 * written part of the line.
		 */
		if (len + vip->lcontinue > sp->cols)
			len = sp->cols - vip->lcontinue;

		/*
		 * If the first line output, do nothing.  If the second line
		 * output, draw the divider line.  If drew a full screen, we
		 * remove the divider line.  If it's a continuation line, move
		 * to the continuation point, else, move the screen up.
		 */
		if (vip->lcontinue == 0) {
			if (!IS_ONELINE(sp)) {
				if (vip->totalcount == 1) {
					(void)gp->scr_move(sp,
					    LASTLINE(sp) - 1, 0);
					(void)gp->scr_clrtoeol(sp);
					(void)vs_divider(sp);
					F_SET(vip, VIP_DIVIDER);
					++vip->totalcount;
					++vip->linecount;
				}
				if (vip->totalcount == sp->t_maxrows &&
				    F_ISSET(vip, VIP_DIVIDER)) {
					--vip->totalcount;
					--vip->linecount;
					F_CLR(vip, VIP_DIVIDER);
				}
			}
			if (vip->totalcount != 0)
				vs_scroll(sp, NULL, SCROLL_W_QUIT);

			(void)gp->scr_move(sp, LASTLINE(sp), 0);
			++vip->totalcount;
			++vip->linecount;

			if (INTERRUPTED(sp))
				break;
		} else
			(void)gp->scr_move(sp, LASTLINE(sp), vip->lcontinue);

		/* Error messages are in inverse video. */
		if (mtype == M_ERR)
			(void)gp->scr_attr(sp, SA_INVERSE, 1);

		/* Display the line, doing character translation. */
#define	FLUSH {								\
	*cbp = '\0';							\
	(void)gp->scr_addstr(sp, cbuf, cbp - cbuf);			\
	cbp = cbuf;							\
}
		ecbp = (cbp = cbuf) + sizeof(cbuf) - 1;
		for (t = line, tlen = len; tlen--; ++t) {
			ch = *t;
			/*
			 * Replace tabs with spaces, there are places in
			 * ex that do column calculations without looking
			 * at <tabs> -- and all routines that care about
			 * <tabs> do their own expansions.  This catches
			 * <tabs> in things like tag search strings.
			 */
			if (ch == '\t')
				ch = ' ';
			chlen = KEY_LEN(sp, ch);
			if (cbp + chlen >= ecbp)
				FLUSH;
			for (kp = KEY_NAME(sp, ch); chlen--;)
				*cbp++ = *kp++;
		}
		if (cbp > cbuf)
			FLUSH;
		if (mtype == M_ERR)
			(void)gp->scr_attr(sp, SA_INVERSE, 0);

		/* Clear the rest of the line. */
		(void)gp->scr_clrtoeol(sp);

		/* If we loop, it's a new line. */
		vip->lcontinue = 0;

		/* Reset for the next line. */
		line += len;
		llen -= len;
		if (p != NULL) {
			++line;
			--llen;
		}
	}

	/* Set up next continuation line. */
	if (p == NULL)
		gp->scr_cursor(sp, &notused, &vip->lcontinue);
}
Ejemplo n.º 11
0
/* 
 * vs_home --
 *	Home the cursor to the bottom row, left-most column.
 *
 * PUBLIC: void vs_home __P((SCR *));
 */
void
vs_home(SCR *sp)
{
	(void)sp->gp->scr_move(sp, LASTLINE(sp), 0);
	(void)sp->gp->scr_refresh(sp, 0);
}
/*
 * vs_line --
 *	Update one line on the screen.
 *
 * PUBLIC: int vs_line __P((SCR *, SMAP *, size_t *, size_t *));
 */
int
vs_line(SCR *sp, SMAP *smp, size_t *yp, size_t *xp)
{
	unsigned char *kp;
	GS *gp;
	SMAP *tsmp;
	size_t chlen = 0, cno_cnt, cols_per_screen, len, nlen;
	size_t offset_in_char, offset_in_line, oldx, oldy;
	size_t scno, skip_cols, skip_screens;
	int dne, is_cached, is_partial, is_tab, no_draw;
	int list_tab, list_dollar;
	CHAR_T *p;
	CHAR_T *cbp, *ecbp, cbuf[128];
	ARG_CHAR_T ch = L('\0');

#if defined(DEBUG) && 0
	vtrace(sp, "vs_line: row %u: line: %u off: %u\n",
	    smp - HMAP, smp->lno, smp->off);
#endif
	/*
	 * If ex modifies the screen after ex output is already on the screen,
	 * don't touch it -- we'll get scrolling wrong, at best.
	 */
	no_draw = 0;
	if (!F_ISSET(sp, SC_TINPUT_INFO) && VIP(sp)->totalcount > 1)
		no_draw = 1;
	if (F_ISSET(sp, SC_SCR_EXWROTE) && (size_t)(smp - HMAP) != LASTLINE(sp))
		no_draw = 1;

	/*
	 * Assume that, if the cache entry for the line is filled in, the
	 * line is already on the screen, and all we need to do is return
	 * the cursor position.  If the calling routine doesn't need the
	 * cursor position, we can just return.
	 */
	is_cached = SMAP_CACHE(smp);
	if (yp == NULL && (is_cached || no_draw))
		return (0);

	/*
	 * A nasty side effect of this routine is that it returns the screen
	 * position for the "current" character.  Not pretty, but this is the
	 * only routine that really knows what's out there.
	 *
	 * Move to the line.  This routine can be called by vs_sm_position(),
	 * which uses it to fill in the cache entry so it can figure out what
	 * the real contents of the screen are.  Because of this, we have to
	 * return to whereever we started from.
	 */
	gp = sp->gp;
	(void)gp->scr_cursor(sp, &oldy, &oldx);
	(void)gp->scr_move(sp, smp - HMAP, 0);

	/* Get the line. */
	dne = db_get(sp, smp->lno, 0, &p, &len);

	/*
	 * Special case if we're printing the info/mode line.  Skip printing
	 * the leading number, as well as other minor setup.  The only time
	 * this code paints the mode line is when the user is entering text
	 * for a ":" command, so we can put the code here instead of dealing
	 * with the empty line logic below.  This is a kludge, but it's pretty
	 * much confined to this module.
	 *
	 * Set the number of columns for this screen.
	 * Set the number of chars or screens to skip until a character is to
	 * be displayed.
	 */
	cols_per_screen = sp->cols;
	if (O_ISSET(sp, O_LEFTRIGHT)) {
		skip_screens = 0;
		skip_cols = smp->coff;
	} else {
		skip_screens = smp->soff - 1;
		skip_cols = skip_screens * cols_per_screen;
	}

	list_tab = O_ISSET(sp, O_LIST);
	if (F_ISSET(sp, SC_TINPUT_INFO))
		list_dollar = 0;
	else {
		list_dollar = list_tab;

		/*
		 * If O_NUMBER is set, the line doesn't exist and it's line
		 * number 1, i.e., an empty file, display the line number.
		 *
		 * If O_NUMBER is set, the line exists and the first character
		 * on the screen is the first character in the line, display
		 * the line number.
		 *
		 * !!!
		 * If O_NUMBER set, decrement the number of columns in the
		 * first screen.  DO NOT CHANGE THIS -- IT'S RIGHT!  The
		 * rest of the code expects this to reflect the number of
		 * columns in the first screen, regardless of the number of
		 * columns we're going to skip.
		 */
		if (O_ISSET(sp, O_NUMBER)) {
			cols_per_screen -= O_NUMBER_LENGTH;
			if ((!dne || smp->lno == 1) && skip_cols == 0) {
				nlen = snprintf((char*)cbuf,
				    sizeof(cbuf), O_NUMBER_FMT,
				    (unsigned long)smp->lno);
				(void)gp->scr_addstr(sp, (char*)cbuf, nlen);
			}
		}
	}

	/*
	 * Special case non-existent lines and the first line of an empty
	 * file.  In both cases, the cursor position is 0, but corrected
	 * as necessary for the O_NUMBER field, if it was displayed.
	 */
	if (dne || len == 0) {
		/* Fill in the cursor. */
		if (yp != NULL && smp->lno == sp->lno) {
			*yp = smp - HMAP;
			*xp = sp->cols - cols_per_screen;
		}

		/* If the line is on the screen, quit. */
		if (is_cached || no_draw)
			goto ret1;

		/* Set line cache information. */
		smp->c_sboff = smp->c_eboff = 0;
		smp->c_scoff = smp->c_eclen = 0;

		/*
		 * Lots of special cases for empty lines, but they only apply
		 * if we're displaying the first screen of the line.
		 */
		if (skip_cols == 0) {
			if (dne) {
				if (smp->lno == 1) {
					if (list_dollar) {
						ch = L('$');
						goto empty;
					}
				} else {
					ch = L('~');
					goto empty;
				}
			} else
				if (list_dollar) {
					ch = L('$');
empty:					(void)gp->scr_addstr(sp,
					    (const char *)KEY_NAME(sp, ch),
					    KEY_LEN(sp, ch));
				}
		}

		(void)gp->scr_clrtoeol(sp);
		(void)gp->scr_move(sp, oldy, oldx);
		return (0);
	}

	/* If we shortened this line in another screen, the cursor
	 * position may have fallen off.
	 */
	if (sp->lno == smp->lno && sp->cno >= len)
	    sp->cno = len - 1;

	/*
	 * If we just wrote this or a previous line, we cached the starting
	 * and ending positions of that line.  The way it works is we keep
	 * information about the lines displayed in the SMAP.  If we're
	 * painting the screen in the forward direction, this saves us from
	 * reformatting the physical line for every line on the screen.  This
	 * wins big on binary files with 10K lines.
	 *
	 * Test for the first screen of the line, then the current screen line,
	 * then the line behind us, then do the hard work.  Note, it doesn't
	 * do us any good to have a line in front of us -- it would be really
	 * hard to try and figure out tabs in the reverse direction, i.e. how
	 * many spaces a tab takes up in the reverse direction depends on
	 * what characters preceded it.
	 *
	 * Test for the first screen of the line.
	 */
	if (skip_cols == 0) {
		smp->c_sboff = offset_in_line = 0;
		smp->c_scoff = offset_in_char = 0;
		p = &p[offset_in_line];
		goto display;
	}

	/* Test to see if we've seen this exact line before. */
	if (is_cached) {
		offset_in_line = smp->c_sboff;
		offset_in_char = smp->c_scoff;
		p = &p[offset_in_line];

		/* Set cols_per_screen to 2nd and later line length. */
		if (O_ISSET(sp, O_LEFTRIGHT) || skip_cols > cols_per_screen)
			cols_per_screen = sp->cols;
		goto display;
	}

	/* Test to see if we saw an earlier part of this line before. */
	if (smp != HMAP &&
	    SMAP_CACHE(tsmp = smp - 1) && tsmp->lno == smp->lno) {
		if (tsmp->c_eclen != tsmp->c_ecsize) {
			offset_in_line = tsmp->c_eboff;
			offset_in_char = tsmp->c_eclen;
		} else {
			offset_in_line = tsmp->c_eboff + 1;
			offset_in_char = 0;
		}

		/* Put starting info for this line in the cache. */
		smp->c_sboff = offset_in_line;
		smp->c_scoff = offset_in_char;
		p = &p[offset_in_line];

		/* Set cols_per_screen to 2nd and later line length. */
		if (O_ISSET(sp, O_LEFTRIGHT) || skip_cols > cols_per_screen)
			cols_per_screen = sp->cols;
		goto display;
	}

	scno = 0;
	offset_in_line = 0;
	offset_in_char = 0;

	/* Do it the hard way, for leftright scrolling screens. */
	if (O_ISSET(sp, O_LEFTRIGHT)) {
		for (; offset_in_line < len; ++offset_in_line) {
			chlen = (ch = (UCHAR_T)*p++) == L('\t') && !list_tab ?
			    TAB_OFF(scno) : KEY_COL(sp, ch);
			if ((scno += chlen) >= skip_cols)
				break;
		}

		/* Set cols_per_screen to 2nd and later line length. */
		cols_per_screen = sp->cols;

		/* Put starting info for this line in the cache. */
		if (offset_in_line >= len) {
			smp->c_sboff = offset_in_line;
			smp->c_scoff = 255;
		} else if (scno != skip_cols) {
			smp->c_sboff = offset_in_line;
			smp->c_scoff =
			    offset_in_char = chlen - (scno - skip_cols);
			--p;
		} else {
			smp->c_sboff = ++offset_in_line;
			smp->c_scoff = 0;
		}
	}

	/* Do it the hard way, for historic line-folding screens. */
	else {
		for (; offset_in_line < len; ++offset_in_line) {
			chlen = (ch = (UCHAR_T)*p++) == L('\t') && !list_tab ?
			    TAB_OFF(scno) : KEY_COL(sp, ch);
			if ((scno += chlen) < cols_per_screen)
				continue;
			scno -= cols_per_screen;

			/* Set cols_per_screen to 2nd and later line length. */
			cols_per_screen = sp->cols;

			/*
			 * If crossed the last skipped screen boundary, start
			 * displaying the characters.
			 */
			if (--skip_screens == 0)
				break;
		}

		/* Put starting info for this line in the cache. */
		if (scno != 0) {
			smp->c_sboff = offset_in_line;
			smp->c_scoff = offset_in_char = chlen - scno;
			--p;
		} else {
			smp->c_sboff = ++offset_in_line;
			smp->c_scoff = 0;
		}
	}

display:
	/*
	 * Set the number of characters to skip before reaching the cursor
	 * character.  Offset by 1 and use 0 as a flag value.  Vs_line is
	 * called repeatedly with a valid pointer to a cursor position.
	 * Don't fill anything in unless it's the right line and the right
	 * character, and the right part of the character...
	 */
	if (yp == NULL ||
	    smp->lno != sp->lno || sp->cno < offset_in_line ||
	    offset_in_line + cols_per_screen < sp->cno) {
		cno_cnt = 0;
		/* If the line is on the screen, quit. */
		if (is_cached || no_draw)
			goto ret1;
	} else
		cno_cnt = (sp->cno - offset_in_line) + 1;

	/* This is the loop that actually displays characters. */
	ecbp = (cbp = cbuf) + sizeof(cbuf)/sizeof(CHAR_T) - 1;
	for (is_partial = 0, scno = 0;
	    offset_in_line < len; ++offset_in_line, offset_in_char = 0) {
		if ((ch = (UCHAR_T)*p++) == L('\t') && !list_tab) {
			scno += chlen = TAB_OFF(scno) - offset_in_char;
			is_tab = 1;
		} else {
			scno += chlen = KEY_COL(sp, ch) - offset_in_char;
			is_tab = 0;
		}

		/*
		 * Only display up to the right-hand column.  Set a flag if
		 * the entire character wasn't displayed for use in setting
		 * the cursor.  If reached the end of the line, set the cache
		 * info for the screen.  Don't worry about there not being
		 * characters to display on the next screen, its lno/off won't
		 * match up in that case.
		 */
		if (scno >= cols_per_screen) {
			if (is_tab == 1) {
				chlen -= scno - cols_per_screen;
				smp->c_ecsize = smp->c_eclen = chlen;
				scno = cols_per_screen;
			} else {
				smp->c_ecsize = chlen;
				chlen -= scno - cols_per_screen;
				smp->c_eclen = chlen;

				if (scno > cols_per_screen)
					is_partial = 1;
			}
			smp->c_eboff = offset_in_line;

			/* Terminate the loop. */
			offset_in_line = len;
		}

		/*
		 * If the caller wants the cursor value, and this was the
		 * cursor character, set the value.  There are two ways to
		 * put the cursor on a character -- if it's normal display
		 * mode, it goes on the last column of the character.  If
		 * it's input mode, it goes on the first.  In normal mode,
		 * set the cursor only if the entire character was displayed.
		 */
		if (cno_cnt &&
		    --cno_cnt == 0 && (F_ISSET(sp, SC_TINPUT) || !is_partial)) {
			*yp = smp - HMAP;
			if (F_ISSET(sp, SC_TINPUT))
				if (is_partial)
					*xp = scno - smp->c_ecsize;
				else
					*xp = scno - chlen;
			else
				*xp = scno - 1;
			if (O_ISSET(sp, O_NUMBER) &&
			    !F_ISSET(sp, SC_TINPUT_INFO) && skip_cols == 0)
				*xp += O_NUMBER_LENGTH;

			/* If the line is on the screen, quit. */
			if (is_cached || no_draw)
				goto ret1;
		}

		/* If the line is on the screen, don't display anything. */
		if (is_cached || no_draw)
			continue;

#define	FLUSH {								\
	*cbp = '\0';							\
	(void)gp->scr_waddstr(sp, cbuf, cbp - cbuf);			\
	cbp = cbuf;							\
}
		/*
		 * Display the character.  We do tab expansion here because
		 * the screen interface doesn't have any way to set the tab
		 * length.  Note, it's theoretically possible for chlen to
		 * be larger than cbuf, if the user set a impossibly large
		 * tabstop.
		 */
		if (is_tab)
			while (chlen--) {
				if (cbp >= ecbp)
					FLUSH;
				*cbp++ = TABCH;
			}
		else {
			if (cbp + chlen >= ecbp)
				FLUSH;

			/* don't display half a wide character */
			if (is_partial && CHAR_WIDTH(sp, ch) > 1) {
				*cbp++ = ' ';
				break;
			}

			/* XXXX this needs some rethinking */
			if (INTISWIDE(ch)) {
				/* Put a space before non-spacing char. */
				if (CHAR_WIDTH(sp, ch) <= 0)
					*cbp++ = L(' ');
				*cbp++ = ch;
			} else
				for (kp = KEY_NAME(sp, ch) + offset_in_char; 
				     chlen--;)
					*cbp++ = (u_char)*kp++;
		}
	}

	if (scno < cols_per_screen) {
		/* If didn't paint the whole line, update the cache. */
		smp->c_ecsize = smp->c_eclen = KEY_LEN(sp, ch);
		smp->c_eboff = len - 1;

		/*
		 * If not the info/mode line, and O_LIST set, and at the
		 * end of the line, and the line ended on this screen,
		 * add a trailing $.
		 */
		if (list_dollar) {
			++scno;

			chlen = KEY_LEN(sp, L('$'));
			if (cbp + chlen >= ecbp)
				FLUSH;
			for (kp = KEY_NAME(sp, L('$')); chlen--;)
				*cbp++ = *kp++;
		}

		/* If still didn't paint the whole line, clear the rest. */
		if (scno < cols_per_screen)
			(void)gp->scr_clrtoeol(sp);
	}

	/* Flush any buffered characters. */
	if (cbp > cbuf)
		FLUSH;

ret1:	(void)gp->scr_move(sp, oldy, oldx);
	return (0);
}