📄 edstruct.c
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* 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.
*/
globle int bclear(
void *theEnv,
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(theEnv,"Discard changes")) != TRUE)
return (s);
bp->b_flag &= ~BFCHG; /* Not changed */
while ((lp=lforw(bp->b_linep)) != bp->b_linep)
lfree(theEnv,lp);
bp->b_dotp = bp->b_linep; /* Fix "." */
bp->b_doto = 0;
bp->b_markp = NULL; /* Invalidate "mark" */
bp->b_marko = 0;
return (TRUE);
}
/* ==========================================================================
* LINE MANAGEMENT FUNCTIONS
* ==========================================================================
*/
/*
* The functions in this section are a general set of line management utilities.
* They are the only routines that touch the text. They also touch the buffer
* and window structures, to make sure that the necessary updating gets done.
* There are routines in this section that handle the kill buffer too. It isn't
* here for any good reason.
*
* Note that this code only updates the dot and mark values in the window list.
* Since all the code acts on the current window, the buffer that we are
* editing must be being displayed, which means that "b_nwnd" is non zero,
* which means that the dot and mark values in the buffer headers are nonsense.
*/
/*
* This routine allocates a block of memory large enough to hold a LINE
* containing "used" characters. The block is always rounded up a bit. Return
* a pointer to the new block, or NULL if there isn't any memory left. Print a
* message in the message line if no space.
*/
globle LINE *lalloc(
void *theEnv,
int used)
{
register LINE *lp;
register int size;
size = (used+NBLOCK-1) & ~(NBLOCK-1);
if (size == 0) /* Assume that an empty */
size = NBLOCK; /* line is for type-in. */
lp = (LINE *) genalloc(theEnv,(unsigned) sizeof(LINE)+size);
lp->l_size = size;
lp->l_used = used;
return (lp);
}
/*
* Delete line "lp". Fix all of the links that might point at it (they are
* moved to offset 0 of the next line. Unlink the line from whatever buffer it
* might be in. Release the memory. The buffers are updated too; the magic
* conditions described in the above comments don't hold here.
*/
globle void lfree(
void *theEnv,
LINE *lp)
{
register BUFFER *bp;
register WINDOW *wp;
wp = wheadp;
while (wp != NULL) {
if (wp->w_linep == lp)
wp->w_linep = lp->l_fp;
if (wp->w_dotp == lp) {
wp->w_dotp = lp->l_fp;
wp->w_doto = 0;
}
if (wp->w_markp == lp) {
wp->w_markp = lp->l_fp;
wp->w_marko = 0;
}
wp = wp->w_wndp;
}
bp = bheadp;
while (bp != NULL) {
if (bp->b_nwnd == 0) {
if (bp->b_dotp == lp) {
bp->b_dotp = lp->l_fp;
bp->b_doto = 0;
}
if (bp->b_markp == lp) {
bp->b_markp = lp->l_fp;
bp->b_marko = 0;
}
}
bp = bp->b_bufp;
}
lp->l_bp->l_fp = lp->l_fp;
lp->l_fp->l_bp = lp->l_bp;
genfree(theEnv,(void *) lp, (unsigned) (sizeof(LINE) + lp->l_size));
}
/*
* This routine gets called when a character is changed in place in the current
* buffer. It updates all of the required flags in the buffer and window
* system. The flag used is passed as an argument; if the buffer is being
* displayed in more than 1 window we change EDIT t HARD. Set MODE if the
* mode line needs to be updated (the "*" has to be set).
*/
globle void lchange(
int flag)
{
register WINDOW *wp;
if (curbp->b_nwnd != 1) /* Ensure hard. */
flag = WFHARD;
if ((curbp->b_flag&BFCHG) == 0) { /* First change, so */
flag |= WFMODE; /* update mode lines. */
curbp->b_flag |= BFCHG;
}
wp = wheadp;
while (wp != NULL) {
if (wp->w_bufp == curbp)
wp->w_flag |= flag;
wp = wp->w_wndp;
}
}
/*
* Insert "n" copies of the character "c" at the current location of dot. In
* the easy case all that happens is the text is stored in the line. In the
* hard case, the line has to be reallocated. When the window list is updated,
* take special care; I screwed it up once. You always update dot in the
* current window. You update mark, and a dot in another window, if it is
* greater than the place where you did the insert. Return TRUE if all is
* well, and FALSE on errors.
*/
globle int linsert(
void *theEnv,
int n,
int c)
{
register char *cp1;
register char *cp2;
register LINE *lp1;
register LINE *lp2;
register LINE *lp3;
register int doto;
register int i;
register WINDOW *wp;
lchange(WFEDIT);
lp1 = curwp->w_dotp; /* Current line */
if (lp1 == curbp->b_linep) { /* At the end: special */
if (curwp->w_doto != 0) {
mlwrite("bug: linsert");
return (FALSE);
}
if ((lp2=lalloc(theEnv,n)) == NULL) /* Allocate new line */
return (FALSE);
lp3 = lp1->l_bp; /* Previous line */
lp3->l_fp = lp2; /* Link in */
lp2->l_fp = lp1;
lp1->l_bp = lp2;
lp2->l_bp = lp3;
for (i=0; i<n; ++i)
lp2->l_text[i] = (char) c;
curwp->w_dotp = lp2;
curwp->w_doto = n;
return (TRUE);
}
doto = curwp->w_doto; /* Save for later. */
if (lp1->l_used+n > lp1->l_size) { /* Hard: reallocate */
if ((lp2=lalloc(theEnv,lp1->l_used+n)) == NULL)
return (FALSE);
cp1 = &lp1->l_text[0];
cp2 = &lp2->l_text[0];
while (cp1 != &lp1->l_text[doto])
*cp2++ = *cp1++;
cp2 += n;
while (cp1 != &lp1->l_text[lp1->l_used])
*cp2++ = *cp1++;
lp1->l_bp->l_fp = lp2;
lp2->l_fp = lp1->l_fp;
lp1->l_fp->l_bp = lp2;
lp2->l_bp = lp1->l_bp;
genfree(theEnv,(void *) lp1, (unsigned) (sizeof(LINE) + lp1->l_size));
} else { /* Easy: in place */
lp2 = lp1; /* Pretend new line */
lp2->l_used += n;
cp2 = &lp1->l_text[lp1->l_used];
cp1 = cp2-n;
while (cp1 != &lp1->l_text[doto])
*--cp2 = *--cp1;
}
for (i=0; i<n; ++i) /* Add the characters */
lp2->l_text[doto+i] = (char) c;
wp = wheadp; /* Update windows */
while (wp != NULL) {
if (wp->w_linep == lp1)
wp->w_linep = lp2;
if (wp->w_dotp == lp1) {
wp->w_dotp = lp2;
if (wp==curwp || wp->w_doto>doto)
wp->w_doto += n;
}
if (wp->w_markp == lp1) {
wp->w_markp = lp2;
if (wp->w_marko > doto)
wp->w_marko += n;
}
wp = wp->w_wndp;
}
return (TRUE);
}
/*
* Insert a newline into the buffer at the current location of dot in the
* current window. The funny ass-backwards way it does things is not a botch;
* it just makes the last line in the file not a special case. Return TRUE if
* everything works out and FALSE on error (memory allocation failure). The
* update of dot and mark is a bit easier then in the above case, because the
* split forces more updating.
*/
globle int lnewline(
void *theEnv)
{
register char *cp1;
register char *cp2;
register LINE *lp1;
register LINE *lp2;
register int doto;
register WINDOW *wp;
lchange(WFHARD);
lp1 = curwp->w_dotp; /* Get the address and */
doto = curwp->w_doto; /* offset of "." */
if ((lp2=lalloc(theEnv,doto)) == NULL) /* New first half line */
return (FALSE);
cp1 = &lp1->l_text[0]; /* Shuffle text around */
cp2 = &lp2->l_text[0];
while (cp1 != &lp1->l_text[doto])
*cp2++ = *cp1++;
cp2 = &lp1->l_text[0];
while (cp1 != &lp1->l_text[lp1->l_used])
*cp2++ = *cp1++;
lp1->l_used -= doto;
lp2->l_bp = lp1->l_bp;
lp1->l_bp = lp2;
lp2->l_bp->l_fp = lp2;
lp2->l_fp = lp1;
wp = wheadp; /* Windows */
while (wp != NULL) {
if (wp->w_linep == lp1)
wp->w_linep = lp2;
if (wp->w_dotp == lp1) {
if (wp->w_doto < doto)
wp->w_dotp = lp2;
else
wp->w_doto -= doto;
}
if (wp->w_markp == lp1) {
if (wp->w_marko < doto)
wp->w_markp = lp2;
else
wp->w_marko -= doto;
}
wp = wp->w_wndp;
}
return (TRUE);
}
/*
* This function deletes "n" bytes, starting at dot. It understands how do deal
* with end of lines, etc. It returns TRUE if all of the characters were
* deleted, and FALSE if they were not (because dot ran into the end of the
* buffer. The "kflag" is TRUE if the text should be put in the kill buffer.
*/
globle int ldelete(
void *theEnv,
long n,
int kflag)
{
register char *cp1;
register char *cp2;
register LINE *dotp;
register int doto;
register int chunk;
register WINDOW *wp;
while (n != 0) {
dotp = curwp->w_dotp;
doto = curwp->w_doto;
if (dotp == curbp->b_linep) /* Hit end of buffer. */
return (FALSE);
chunk = dotp->l_used-doto; /* Size of chunk. */
if (chunk > (int) n)
chunk = (int) n;
if (chunk == 0) { /* End of line, merge. */
lchange(WFHARD);
if (ldelnewline(theEnv) == FALSE
|| (kflag!=FALSE && kinsert(theEnv,'\n')==FALSE))
return (FALSE);
--n;
continue;
}
lchange(WFEDIT);
cp1 = &dotp->l_text[doto]; /* Scrunch text. */
cp2 = cp1 + chunk;
if (kflag != FALSE) { /* Kill? */
while (cp1 != cp2) {
if (kinsert(theEnv,*cp1) == FALSE)
return (FALSE);
++cp1;
}
cp1 = &dotp->l_text[doto];
}
while (cp2 != &dotp->l_text[dotp->l_used])
*cp1++ = *cp2++;
dotp->l_used -= chunk;
wp = wheadp; /* Fix windows */
while (wp != NULL) {
if (wp->w_dotp==dotp && wp->w_doto>=doto) {
wp->w_doto -= chunk;
if (wp->w_doto < doto)
wp->w_doto = doto;
}
if (wp->w_markp==dotp && wp->w_marko>=doto) {
wp->w_marko -= chunk;
if (wp->w_marko < doto)
wp->w_marko = doto;
}
wp = wp->w_wndp;
}
n -= chunk;
}
return (TRUE);
}
/*
* Delete a newline. Join the current line with the next line. If the next line
* is the magic header line always return TRUE; merging the last line with the
* header line can be thought of as always being a successful operation, even
* if nothing is done, and this makes the kill buffer work "right". Easy cases
* can be done by shuffling data around. Hard cases require that lines be moved
* about in memory. Return FALSE on error and TRUE if all looks ok. Called by
* "ldelete" only.
*/
globle int ldelnewline(
void *theEnv)
{
register char *cp1;
register char *cp2;
register LINE *lp1;
register LINE *lp2;
register LINE *lp3;
register WINDOW *wp;
lp1 = curwp->w_dotp;
lp2 = lp1->l_fp;
if (lp2 == curbp->b_linep) { /* At the buffer end. */
if (lp1->l_used == 0) /* Blank line. */
lfree(theEnv,lp1);
return (TRUE);
}
if (lp2->l_used <= lp1->l_size-lp1->l_used) {
cp1 = &lp1->l_text[lp1->l_used];
cp2 = &lp2->l_text[0];
while (cp2 != &lp2->l_text[lp2->l_used])
*cp1++ = *cp2++;
wp = wheadp;
while (wp != NULL) {
if (wp->w_linep == lp2)
wp->w_linep = lp1;
if (wp->w_dotp == lp2) {
wp->w_dotp = lp1;
wp->w_doto += lp1->l_used;
}
if (wp->w_markp == lp2) {
wp->w_markp = lp1;
wp->w_marko += lp1->l_used;
}
wp = wp->w_wndp;
}
lp1->l_used += lp2->l_used;
lp1->l_fp = lp2->l_fp;
lp2->l_fp->l_bp = lp1;
genfree(theEnv,(void *) lp2, (unsigned) (sizeof(LINE) + lp2->l_size));
return (TRUE);
}
if ((lp3=lalloc(theEnv,lp1->l_used+lp2->l_used)) == NULL)
return (FALSE);
cp1 = &lp1->l_text[0];
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