dos_compilers/Mark Williams MWC v4/SAMPLE/WINDOW.C
2024-07-01 16:08:53 -07:00

389 lines
9.2 KiB
C

/*
* Window management.
* Some of the functions are internal,
* and some are attached to keys that the
* user actually types.
*/
#include <stdio.h>
#include "ed.h"
/*
* Reposition dot in the current
* window to line "n". If the argument is
* positive, it is that line. If it is negative it
* is that line from the bottom. If it is 0 the window
* is centered (this is what the standard redisplay code
* does). With no argument it defaults to 1. Bound to
* M-!. Because of the default, it works like in
* Gosling.
*/
reposition(f, n)
{
curwp->w_force = n;
curwp->w_flag |= WFFORCE;
return (TRUE);
}
/*
* Refresh the screen. With no
* argument, it just does the refresh. With an
* argument it recenters "." in the current
* window. Bound to "C-L".
*/
refresh(f, n)
{
if (f == FALSE)
sgarbf = TRUE;
else {
curwp->w_force = 0; /* Center dot. */
curwp->w_flag |= WFFORCE;
}
return (TRUE);
}
/*
* The command make the next
* window (next => down the screen)
* the current window. There are no real
* errors, although the command does
* nothing if there is only 1 window on
* the screen. Bound to "C-X C-N".
*/
nextwind(f, n)
{
register WINDOW *wp;
if ((wp=curwp->w_wndp) == NULL)
wp = wheadp;
curwp = wp;
curbp = wp->w_bufp;
return (TRUE);
}
/*
* This command makes the previous
* window (previous => up the screen) the
* current window. There arn't any errors,
* although the command does not do a lot
* if there is 1 window.
*/
prevwind(f, n)
{
register WINDOW *wp1;
register WINDOW *wp2;
wp1 = wheadp;
wp2 = curwp;
if (wp1 == wp2)
wp2 = NULL;
while (wp1->w_wndp != wp2)
wp1 = wp1->w_wndp;
curwp = wp1;
curbp = wp1->w_bufp;
return (TRUE);
}
/*
* This command moves the current
* window down by "arg" lines. Recompute
* the top line in the window. The move up and
* move down code is almost completely the same;
* most of the work has to do with reframing the
* window, and picking a new dot. We share the
* code by having "move down" just be an interface
* to "move up". Magic. Bound to "C-X C-N".
*/
mvdnwind(f, n)
register int n;
{
return (mvupwind(f, -n));
}
/*
* Move the current window up by "arg"
* lines. Recompute the new top line of the window.
* Look to see if "." is still on the screen. If it is,
* you win. If it isn't, then move "." to center it
* in the new framing of the window (this command does
* not really move "."; it moves the frame). Bound
* to "C-X C-P".
*/
mvupwind(f, n)
register int n;
{
register LINE *lp;
register int i;
lp = curwp->w_linep;
if (n < 0) {
while (n++ && lp!=curbp->b_linep)
lp = lforw(lp);
} else {
while (n-- && lback(lp)!=curbp->b_linep)
lp = lback(lp);
}
curwp->w_linep = lp;
curwp->w_flag |= WFHARD; /* Mode line is OK. */
for (i=0; i<curwp->w_ntrows; ++i) {
if (lp == curwp->w_dotp)
return (TRUE);
if (lp == curbp->b_linep)
break;
lp = lforw(lp);
}
lp = curwp->w_linep;
i = curwp->w_ntrows/2;
while (i-- && lp!=curbp->b_linep)
lp = lforw(lp);
curwp->w_dotp = lp;
curwp->w_doto = 0;
return (TRUE);
}
/*
* This command makes the current
* window the only window on the screen.
* Bound to "C-X 1". Try to set the framing
* so that "." does not have to move on
* the display. Some care has to be taken
* to keep the values of dot and mark
* in the buffer structures right if the
* distruction of a window makes a buffer
* become undisplayed.
*/
onlywind(f, n)
{
register WINDOW *wp;
register LINE *lp;
register int i;
while (wheadp != curwp) {
wp = wheadp;
wheadp = wp->w_wndp;
if (--wp->w_bufp->b_nwnd == 0) {
wp->w_bufp->b_dotp = wp->w_dotp;
wp->w_bufp->b_doto = wp->w_doto;
wp->w_bufp->b_markp = wp->w_markp;
wp->w_bufp->b_marko = wp->w_marko;
}
free((char *) wp);
}
while (curwp->w_wndp != NULL) {
wp = curwp->w_wndp;
curwp->w_wndp = wp->w_wndp;
if (--wp->w_bufp->b_nwnd == 0) {
wp->w_bufp->b_dotp = wp->w_dotp;
wp->w_bufp->b_doto = wp->w_doto;
wp->w_bufp->b_markp = wp->w_markp;
wp->w_bufp->b_marko = wp->w_marko;
}
free((char *) wp);
}
lp = curwp->w_linep;
i = curwp->w_toprow;
while (i!=0 && lback(lp)!=curbp->b_linep) {
--i;
lp = lback(lp);
}
curwp->w_toprow = 0;
curwp->w_ntrows = term.t_nrow-1;
curwp->w_linep = lp;
curwp->w_flag |= WFMODE|WFHARD;
return (TRUE);
}
/*
* Split the current window. A window
* smaller than 3 lines cannot be split.
* The only other error that is possible is
* a "malloc" failure allocating the structure
* for the new window. Bound to "C-X 2".
*/
splitwind(f, n)
{
register WINDOW *wp;
register LINE *lp;
register int ntru;
register int ntrl;
register int ntrd;
register WINDOW *wp1;
register WINDOW *wp2;
if (curwp->w_ntrows < 3) {
mlwrite("Cannot split a %d line window", curwp->w_ntrows);
return (FALSE);
}
if ((wp = (WINDOW *) malloc(sizeof(WINDOW))) == NULL) {
mlwrite("Cannot allocate WINDOW block");
return (FALSE);
}
++curbp->b_nwnd; /* Displayed twice. */
wp->w_bufp = curbp;
wp->w_dotp = curwp->w_dotp;
wp->w_doto = curwp->w_doto;
wp->w_markp = curwp->w_markp;
wp->w_marko = curwp->w_marko;
wp->w_flag = 0;
wp->w_force = 0;
ntru = (curwp->w_ntrows-1) / 2; /* Upper size */
ntrl = (curwp->w_ntrows-1) - ntru; /* Lower size */
lp = curwp->w_linep;
ntrd = 0;
while (lp != curwp->w_dotp) {
++ntrd;
lp = lforw(lp);
}
lp = curwp->w_linep;
if (ntrd <= ntru) { /* Old is upper window. */
if (ntrd == ntru) /* Hit mode line. */
lp = lforw(lp);
curwp->w_ntrows = ntru;
wp->w_wndp = curwp->w_wndp;
curwp->w_wndp = wp;
wp->w_toprow = curwp->w_toprow+ntru+1;
wp->w_ntrows = ntrl;
} else { /* Old is lower window */
wp1 = NULL;
wp2 = wheadp;
while (wp2 != curwp) {
wp1 = wp2;
wp2 = wp2->w_wndp;
}
if (wp1 == NULL)
wheadp = wp;
else
wp1->w_wndp = wp;
wp->w_wndp = curwp;
wp->w_toprow = curwp->w_toprow;
wp->w_ntrows = ntru;
++ntru; /* Mode line. */
curwp->w_toprow += ntru;
curwp->w_ntrows = ntrl;
while (ntru--)
lp = lforw(lp);
}
curwp->w_linep = lp; /* Adjust the top lines */
wp->w_linep = lp; /* if necessary. */
curwp->w_flag |= WFMODE|WFHARD;
wp->w_flag |= WFMODE|WFHARD;
return (TRUE);
}
/*
* Enlarge the current window.
* Find the window that loses space. Make
* sure it is big enough. If so, hack the window
* descriptions, and ask redisplay to do all the
* hard work. You don't just set "force reframe"
* because dot would move. Bound to "C-X Z".
*/
enlargewind(f, n)
{
register WINDOW *adjwp;
register LINE *lp;
register int i;
if (n < 0)
return (shrinkwind(f, -n));
if (wheadp->w_wndp == NULL) {
mlwrite("Only one window");
return (FALSE);
}
if ((adjwp=curwp->w_wndp) == NULL) {
adjwp = wheadp;
while (adjwp->w_wndp != curwp)
adjwp = adjwp->w_wndp;
}
if (adjwp->w_ntrows <= n) {
mlwrite("Impossible change");
return (FALSE);
}
if (curwp->w_wndp == adjwp) { /* Shrink below. */
lp = adjwp->w_linep;
for (i=0; i<n && lp!=adjwp->w_bufp->b_linep; ++i)
lp = lforw(lp);
adjwp->w_linep = lp;
adjwp->w_toprow += n;
} else { /* Shrink above. */
lp = curwp->w_linep;
for (i=0; i<n && lback(lp)!=curbp->b_linep; ++i)
lp = lback(lp);
curwp->w_linep = lp;
curwp->w_toprow -= n;
}
curwp->w_ntrows += n;
adjwp->w_ntrows -= n;
curwp->w_flag |= WFMODE|WFHARD;
adjwp->w_flag |= WFMODE|WFHARD;
return (TRUE);
}
/*
* Shrink the current window.
* Find the window that gains space. Hack at
* the window descriptions. Ask the redisplay to
* do all the hard work. Bound to "C-X C-Z".
*/
shrinkwind(f, n)
{
register WINDOW *adjwp;
register LINE *lp;
register int i;
if (n < 0)
return (enlargewind(f, -n));
if (wheadp->w_wndp == NULL) {
mlwrite("Only one window");
return (FALSE);
}
if ((adjwp=curwp->w_wndp) == NULL) {
adjwp = wheadp;
while (adjwp->w_wndp != curwp)
adjwp = adjwp->w_wndp;
}
if (curwp->w_ntrows <= n) {
mlwrite("Impossible change");
return (FALSE);
}
if (curwp->w_wndp == adjwp) { /* Grow below. */
lp = adjwp->w_linep;
for (i=0; i<n && lback(lp)!=adjwp->w_bufp->b_linep; ++i)
lp = lback(lp);
adjwp->w_linep = lp;
adjwp->w_toprow -= n;
} else { /* Grow above. */
lp = curwp->w_linep;
for (i=0; i<n && lp!=curbp->b_linep; ++i)
lp = lforw(lp);
curwp->w_linep = lp;
curwp->w_toprow += n;
}
curwp->w_ntrows -= n;
adjwp->w_ntrows += n;
curwp->w_flag |= WFMODE|WFHARD;
adjwp->w_flag |= WFMODE|WFHARD;
return (TRUE);
}
/*
* Pick a window for a pop-up.
* Split the screen if there is only
* one window. Pick the uppermost window that
* isn't the current window. An LRU algorithm
* might be better. Return a pointer, or
* NULL on error.
*/
WINDOW *
wpopup()
{
register WINDOW *wp;
if (wheadp->w_wndp == NULL /* Only 1 window */
&& splitwind(FALSE, 0) == FALSE) /* and it won't split */
return (NULL);
wp = wheadp; /* Find window to use */
while (wp!=NULL && wp==curwp)
wp = wp->w_wndp;
return (wp);
}