/* ARGSUSED */
int
backpage(int f, int n)
{
struct line *lp;
if (!(f & FFARG)) {
n = curwp->w_ntrows - 2; /* Default scroll. */
if (n <= 0) /* Don't blow up if the */
n = 1; /* window is tiny. */
} else if (n < 0)
return (forwpage(f | FFRAND, -n));
lp = curwp->w_linep;
while (n-- && lback(lp) != curbp->b_headp) {
lp = lback(lp);
}
curwp->w_linep = lp;
curwp->w_flag |= WFFULL;
/* if in current window, don't move dot */
for (n = curwp->w_ntrows; n-- && lp != curbp->b_headp; lp = lforw(lp))
if (lp == curwp->w_dotp)
return (TRUE);
/* Move the dot the slow way, for line nos */
while (curwp->w_dotp != curwp->w_linep) {
curwp->w_dotp = lback(curwp->w_dotp);
curwp->w_dotline--;
}
curwp->w_doto = 0;
return (TRUE);
}
/*
* Implements the vi "^B" command.
*
* This command is like "forwpage", but it goes backwards.
*/
int
backpage(int f, int n)
{
LINE *lp;
int status;
if ((n = full_pages(f, n)) < 0)
return forwpage(f, -n);
lp = curwp->w_line.l;
if (lback(lp) != buf_head(curbp)) {
while ((n -= line_height(curwp, lp)) >= 0
&& lback(lp) != buf_head(curbp))
lp = lback(lp);
curwp->w_line.l = lp;
(void) gotoeos(FALSE, 1);
curwp->w_flag |= WFHARD | WFMODE;
status = TRUE;
} else if (DOT.l != lp) {
DOT.l = lp;
curwp->w_flag |= WFHARD | WFMODE;
status = TRUE;
} else {
status = FALSE;
}
return status;
}
/*
* These functions are provided for compatibility with Gosling's Emacs. They
* are used to scroll the display up (or down) one line at a time.
*/
int
forw1page(int f, int n)
{
if (!(f & FFARG)) {
n = 1;
f = FFUNIV;
}
forwpage(f | FFRAND, n);
return (TRUE);
}
/*
* Page the other window. Check to make sure it exists, then
* nextwind, forwpage and restore window pointers.
*/
int
pagenext(int f, int n)
{
struct mgwin *wp;
if (wheadp->w_wndp == NULL) {
ewprintf("No other window");
return (FALSE);
}
wp = curwp;
(void) nextwind(f, n);
(void) forwpage(f, n);
curwp = wp;
curbp = wp->w_bufp;
return (TRUE);
}
/* ARGSUSED */
int
backpage(int f, int n)
{
struct line *lp, *lp2;
if (!(f & FFARG)) {
n = curwp->w_ntrows - 2; /* Default scroll. */
if (n <= 0) /* Don't blow up if the */
return (backline(f, 1));/* window is tiny. */
} else if (n < 0)
return (forwpage(f | FFRAND, -n));
lp = lp2 = curwp->w_linep;
while (n-- && lback(lp) != curbp->b_headp) {
lp = lback(lp);
}
if (lp == curwp->w_linep) {
dobeep();
ewprintf("Beginning of buffer");
}
curwp->w_linep = lp;
curwp->w_rflag |= WFFULL;
/* if in current window, don't move dot */
for (n = curwp->w_ntrows; n-- && lp != curbp->b_headp; lp = lforw(lp))
if (lp == curwp->w_dotp)
return (TRUE);
lp2 = lforw(lp2);
/* Move the dot the slow way, for line nos */
while (curwp->w_dotp != lp2) {
if (curwp->w_dotline <= curwp->w_ntrows)
goto out;
curwp->w_dotp = lback(curwp->w_dotp);
curwp->w_dotline--;
}
out:
curwp->w_doto = 0;
return (TRUE);
}
/*
* This command is like "forwpage", but it goes backwards. The "2", like
* above, is the overlap between the two windows. The value is from the ITS
* EMACS manual. Bound to "M-V". We do a hard update for exactly the same
* reason.
*/
PASCAL NEAR backpage(
register int f,
register int n )
{
register LINE *lp;
if (f == FALSE) {
n = curwp->w_ntrows - 2; /* Default scroll. */
if (n <= 0) /* Don't blow up if the */
n = 1; /* window is tiny. */
} else if (n < 0)
return(forwpage(f, -n));
lp = curwp->w_linep;
while (n-- && lback(lp)!=curbp->b_linep)
lp = lback(lp);
curwp->w_linep = lp;
curwp->w_dotp = lp;
curwp->w_doto = 0;
curwp->w_flag |= WFHARD;
return(TRUE);
}
/*
* This command is like "forwpage", but it goes backwards. The "2", like
* above, is the overlap between the two windows. The value is from the ITS
* EMACS manual. Bound to "M-V". We do a hard update for exactly the same
* reason.
*/
int backpage (int f, int n)
{
LINE *lp;
if (f == FALSE)
{
n = curwp->w_ntrows - 2; /* Default scroll */
if (n <= 0) /* Don't blow up if the window is tiny */
n = 1;
}
else if (n < 0)
return (forwpage (f, -n));
else /* Convert from pages to lines */
n *= curwp->w_ntrows;
lp = curwp->w_linep;
while (n-- && lback (lp) != curbp->b_linep)
lp = lback (lp);
curwp->w_linep = lp;
curwp->w_dotp = lp;
curwp->w_doto = 0;
curwp->w_flag |= WFHARD;
return (TRUE);
}
