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

359 lines
9.2 KiB
C

/*
* Buffer management.
* Some of the functions are internal,
* and some are actually attached to user
* keys. Like everyone else, they set hints
* for the display system.
*/
#include <stdio.h>
#include "ed.h"
/*
* Attach a buffer to a window. The
* values of dot and mark come from the buffer
* if the use count is 0. Otherwise, they come
* from some other window.
*/
usebuffer(f, n)
{
register BUFFER *bp;
register WINDOW *wp;
register int s;
char bufn[NBUFN];
if ((s=mlreply("Use buffer: ", bufn, NBUFN)) != TRUE)
return (s);
#if GEM
fixname(bufn);
#endif
if ((bp=bfind(bufn, TRUE, 0)) == NULL)
return (FALSE);
if (--curbp->b_nwnd == 0) { /* Last use. */
curbp->b_dotp = curwp->w_dotp;
curbp->b_doto = curwp->w_doto;
curbp->b_markp = curwp->w_markp;
curbp->b_marko = curwp->w_marko;
}
curbp = bp; /* Switch. */
curwp->w_bufp = bp;
curwp->w_linep = bp->b_linep; /* For macros, ignored. */
curwp->w_flag |= WFMODE|WFFORCE|WFHARD; /* Quite nasty. */
if (bp->b_nwnd++ == 0) { /* First use. */
curwp->w_dotp = bp->b_dotp;
curwp->w_doto = bp->b_doto;
curwp->w_markp = bp->b_markp;
curwp->w_marko = bp->b_marko;
return (TRUE);
}
wp = wheadp; /* Look for old. */
while (wp != NULL) {
if (wp!=curwp && wp->w_bufp==bp) {
curwp->w_dotp = wp->w_dotp;
curwp->w_doto = wp->w_doto;
curwp->w_markp = wp->w_markp;
curwp->w_marko = wp->w_marko;
break;
}
wp = wp->w_wndp;
}
return (TRUE);
}
/*
* Dispose of a buffer, by name.
* Ask for the name. Look it up (don't get too
* upset if it isn't there at all!). Get quite upset
* if the buffer is being displayed. Clear the buffer (ask
* if the buffer has been changed). Then free the header
* line and the buffer header. Bound to "C-X K".
*/
killbuffer(f, n)
{
register BUFFER *bp;
register BUFFER *bp1;
register BUFFER *bp2;
register int s;
char bufn[NBUFN];
if ((s=mlreply("Kill buffer: ", bufn, NBUFN)) != TRUE)
return (s);
#if GEM
fixname(bufn);
#endif
if ((bp=bfind(bufn, FALSE, 0)) == NULL) /* Easy if unknown. */
return (TRUE);
if (bp->b_nwnd != 0) { /* Error if on screen. */
mlwrite("Buffer is being displayed");
return (FALSE);
}
if ((s=bclear(bp)) != TRUE) /* Blow text away. */
return (s);
free((char *) bp->b_linep); /* Release header line. */
bp1 = NULL; /* Find the header. */
bp2 = bheadp;
while (bp2 != bp) {
bp1 = bp2;
bp2 = bp2->b_bufp;
}
bp2 = bp2->b_bufp; /* Next one in chain. */
if (bp1 == NULL) /* Unlink it. */
bheadp = bp2;
else
bp1->b_bufp = bp2;
free((char *) bp); /* Release buffer block */
return (TRUE);
}
/*
* List all of the active buffers. First update the special buffer that
* holds the list. Next make sure at least 1 window is displaying the
* buffer list, splitting the screen if this is what it takes.
* Lastly, repaint all of the windows that are displaying the list.
* Bound to "C-X C-B".
*/
listbuffers(f, n)
{
register WINDOW *wp;
register BUFFER *bp;
register int s;
if ((s=makelist()) != TRUE)
return (s);
if (blistp->b_nwnd == 0) { /* Not on screen yet. */
if ((wp=wpopup()) == NULL)
return (FALSE);
bp = wp->w_bufp;
if (--bp->b_nwnd == 0) {
bp->b_dotp = wp->w_dotp;
bp->b_doto = wp->w_doto;
bp->b_markp = wp->w_markp;
bp->b_marko = wp->w_marko;
}
wp->w_bufp = blistp;
++blistp->b_nwnd;
}
wp = wheadp;
while (wp != NULL) {
if (wp->w_bufp == blistp) {
wp->w_linep = lforw(blistp->b_linep);
wp->w_dotp = lforw(blistp->b_linep);
wp->w_doto = 0;
wp->w_markp = NULL;
wp->w_marko = 0;
wp->w_flag |= WFMODE|WFHARD;
}
wp = wp->w_wndp;
}
return (TRUE);
}
/*
* This routine rebuilds the text in the special secret buffer that holds
* the buffer list. It is called by the list buffers command. Return TRUE
* if everything works. Return FALSE if there is an error
* (if there is no memory).
*/
makelist()
{
register char *cp1;
register char *cp2;
register BUFFER *bp;
register LINE *lp;
register long nlines;
register long nbytes;
register int c;
char b[6+1];
char line[128];
blistp->b_flag &= ~BFCHG; /* Don't complain! */
if ((c=bclear(blistp)) != TRUE) /* Blow old text away */
return (c);
strcpy(blistp->b_fname, "");
if (addline("C Size Lines Buffer File") == FALSE
|| addline("- ---- ----- ------ ----") == FALSE)
return (FALSE);
bp = bheadp; /* For all buffers */
while (bp != NULL) {
if ((bp->b_flag&BFTEMP) != 0) { /* Skip magic ones. */
bp = bp->b_bufp;
continue;
}
cp1 = &line[0]; /* Start at left edge */
if ((bp->b_flag&BFCHG) != 0) /* "*" if changed */
*cp1++ = '*';
else
*cp1++ = ' ';
*cp1++ = ' '; /* Gap. */
nbytes = 0; /* Count bytes in buf. */
nlines = 0; /* Count lines in buf. */
lp = lforw(bp->b_linep);
while (lp != bp->b_linep) {
nlines++;
nbytes += llength(lp)+1;
lp = lforw(lp);
}
ltoa(b, 6, nbytes); /* 6 digit buffer size. */
cp2 = &b[0];
while ((c = *cp2++) != 0)
*cp1++ = c;
*cp1++ = ' '; /* Gap. */
ltoa(b, 6, nlines); /* 6 digit # of lines */
cp2 = &b[0];
while ((c = *cp2++) != 0)
*cp1++ = c;
*cp1++ = ' '; /* Gap. */
cp2 = &bp->b_bname[0]; /* Buffer name */
while ((c = *cp2++) != 0)
*cp1++ = c;
cp2 = &bp->b_fname[0]; /* File name */
if (*cp2 != 0) {
while (cp1 < &line[1+1+6+1+6+1+NBUFN+1])
*cp1++ = ' ';
while ((c = *cp2++) != 0) {
if (cp1 < &line[128-1])
*cp1++ = c;
}
}
*cp1 = 0; /* Add to the buffer. */
if (addline(line) == FALSE)
return (FALSE);
bp = bp->b_bufp;
}
return (TRUE); /* All done */
}
ltoa(buf, width, num)
register char buf[];
register int width;
register long num;
{
buf[width] = 0; /* End of string. */
while (num >= 10) { /* Conditional digits. */
buf[--width] = (num%10) + '0';
num /= 10;
}
buf[--width] = num + '0'; /* Always 1 digit. */
while (width != 0) /* Pad with blanks. */
buf[--width] = ' ';
}
/*
* The argument "text" points to a string. Append this line to the buffer list
* buffer. Handcraft the EOL on the end. Return TRUE if it worked and FALSE if
* you ran out of room.
*/
addline(text)
char *text;
{
register LINE *lp;
register int i;
register int ntext;
ntext = strlen(text);
if ((lp=lalloc(ntext)) == NULL)
return (FALSE);
for (i=0; i<ntext; ++i)
lputc(lp, i, text[i]);
blistp->b_linep->l_bp->l_fp = lp; /* Hook onto the end */
lp->l_bp = blistp->b_linep->l_bp;
blistp->b_linep->l_bp = lp;
lp->l_fp = blistp->b_linep;
if (blistp->b_dotp == blistp->b_linep) /* If "." is at the end */
blistp->b_dotp = lp; /* move it to new line */
return (TRUE);
}
/*
* Look through the list of buffers. Return TRUE if there are any changed
* buffers. Buffers that hold magic internal stuff are not considered;
* who cares if the list of buffer names is hacked.
* Return FALSE if no buffers have been changed.
*/
anycb()
{
register BUFFER *bp;
bp = bheadp;
while (bp != NULL) {
if ((bp->b_flag&(BFTEMP|BFNOWRT|BFERROR))==0
&& (bp->b_flag&BFCHG)!=0)
return (TRUE);
bp = bp->b_bufp;
}
return (FALSE);
}
/*
* Find a buffer, by name. Return a pointer to the BUFFER structure
* associated with it. If the named buffer is found, but is a TEMP buffer
* (like the buffer list) conplain. If the buffer is not found and the "cflag"
* is TRUE, create it. The "bflag" is the settings for the flags in in buffer.
*/
BUFFER *bfind(bname, cflag, bflag)
register char *bname;
{
register BUFFER *bp;
register LINE *lp;
bp = bheadp;
while (bp != NULL) {
if (strcmp(bname, bp->b_bname) == 0) {
if ((bp->b_flag&BFTEMP) != 0) {
mlwrite("Cannot select builtin buffer");
return (NULL);
}
return (bp);
}
bp = bp->b_bufp;
}
if (cflag != FALSE) {
if ((bp=(BUFFER *)malloc(sizeof(BUFFER))) == NULL)
return (NULL);
if ((lp=lalloc(0)) == NULL) {
free((char *) bp);
return (NULL);
}
bp->b_bufp = bheadp;
bheadp = bp;
bp->b_dotp = lp;
bp->b_doto = 0;
bp->b_markp = NULL;
bp->b_marko = 0;
bp->b_flag = bflag;
bp->b_nwnd = 0;
bp->b_linep = lp;
strcpy(bp->b_fname, "");
strcpy(bp->b_bname, bname);
lp->l_fp = lp;
lp->l_bp = lp;
}
return (bp);
}
/*
* This routine blows away all of the text in a buffer. If the buffer is
* marked as changed then we ask if it is ok to blow it away; this is
* to save the user the grief of losing text. The window chain is nearly
* always wrong if this gets called; the caller must arrange for the updates
* that are required. Return TRUE if everything looks good.
*/
bclear(bp)
register BUFFER *bp;
{
register LINE *lp;
register int s;
if ((bp->b_flag&BFTEMP) == 0 /* Not scratch buffer. */
&& (bp->b_flag&BFCHG) != 0 /* Something changed */
&& (s=mlyesno("Discard changes")) != TRUE)
return (s);
bp->b_flag &= ~BFCHG; /* Not changed */
while ((lp=lforw(bp->b_linep)) != bp->b_linep)
lfree(lp);
bp->b_dotp = bp->b_linep; /* Fix "." */
bp->b_doto = 0;
bp->b_markp = NULL; /* Invalidate "mark" */
bp->b_marko = 0;
return (TRUE);
}