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mirror of https://github.com/rfivet/uemacs.git synced 2024-12-21 16:46:24 -05:00
uemacs/line.c
2014-12-22 17:43:53 +08:00

789 lines
19 KiB
C

/* line.c
*
* The functions in this file 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 file 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.
*
*/
#include "line.h"
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "buffer.h"
#include "estruct.h"
#include "log.h"
#include "window.h"
int tabmask = 0x07 ; /* tabulator mask */
#define BLOCK_SIZE 16 /* Line block chunk size. */
static int ldelnewline( void) ;
/* The editor holds deleted text chunks in the struct kill buffer. The
* kill buffer is logically a stream of ascii characters, however
* due to its unpredicatable size, it gets implemented as a linked
* list of chunks. (The d_ prefix is for "deleted" text, as k_
* was taken up by the keycode structure).
*/
#define KBLOCK 250 /* sizeof kill buffer chunks */
struct kill {
struct kill *d_next; /* Link to next chunk, NULL if last. */
char d_chunk[KBLOCK]; /* Deleted text. */
};
static struct kill *kbufp = NULL ; /* current kill buffer chunk pointer */
static struct kill *kbufh = NULL ; /* kill buffer header pointer */
static int kused = KBLOCK ; /* # of bytes used in kill buffer */
/*
* return some of the contents of the kill buffer
*/
char *getkill( void)
{
int size; /* max number of chars to return */
static char value[NSTRING]; /* temp buffer for value */
if (kbufh == NULL)
/* no kill buffer....just a null string */
value[0] = 0;
else {
/* copy in the contents... */
if (kused < NSTRING)
size = kused;
else
size = NSTRING - 1;
strncpy(value, kbufh->d_chunk, size);
}
/* and return the constructed value */
return value;
}
/*
* Move the cursor backwards by "n" characters. If "n" is less than zero call
* "forwchar" to actually do the move. Otherwise compute the new cursor
* location. Error if you try and move out of the buffer. Set the flag if the
* line pointer for dot changes.
*/
int backchar(int f, int n)
{
struct line *lp;
if (n < 0)
return forwchar(f, -n);
while (n--) {
if (curwp->w_doto == 0) {
if ((lp = lback(curwp->w_dotp)) == curbp->b_linep)
return FALSE;
curwp->w_dotp = lp;
curwp->w_doto = llength(lp);
curwp->w_flag |= WFMOVE;
} else {
do {
unsigned char c;
curwp->w_doto--;
c = lgetc(curwp->w_dotp, curwp->w_doto);
if (is_beginning_utf8(c))
break;
} while (curwp->w_doto);
}
}
return TRUE;
}
/*
* Move the cursor forwards by "n" characters. If "n" is less than zero call
* "backchar" to actually do the move. Otherwise compute the new cursor
* location, and move ".". Error if you try and move off the end of the
* buffer. Set the flag if the line pointer for dot changes.
*/
int forwchar(int f, int n)
{
if (n < 0)
return backchar(f, -n);
while (n--) {
int len = llength(curwp->w_dotp);
if (curwp->w_doto == len) {
if (curwp->w_dotp == curbp->b_linep)
return FALSE;
curwp->w_dotp = lforw(curwp->w_dotp);
curwp->w_doto = 0;
curwp->w_flag |= WFMOVE;
} else {
do {
unsigned char c;
curwp->w_doto++;
c = lgetc(curwp->w_dotp, curwp->w_doto);
if (is_beginning_utf8(c))
break;
} while (curwp->w_doto < len);
}
}
return TRUE;
}
/*
* This routine allocates a block of memory large enough to hold a struct 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.
*/
struct line *lalloc(int used)
{
struct line *lp;
int size;
size = (used + BLOCK_SIZE - 1) & ~(BLOCK_SIZE - 1);
if (size == 0) /* Assume that is an empty. */
size = BLOCK_SIZE; /* Line is for type-in. */
if ((lp = (struct line *)malloc(sizeof(struct line) + size)) == NULL) {
logwrite( "(OUT OF MEMORY)") ;
return NULL;
}
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.
*/
void lfree(struct line *lp)
{
struct buffer *bp;
struct 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;
free((char *) lp);
}
/*
* 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).
*/
void lchange(int flag)
{
struct 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 spaces forward into text
*
* int f, n; default flag and numeric argument
*/
int insspace(int f, int n)
{
linsert(n, ' ');
backchar(f, n);
return TRUE;
}
/*
* linstr -- Insert a string at the current point
*/
int linstr( char *instr) {
int status = TRUE ;
if( instr != NULL) {
char tmpc ;
while( (tmpc = *instr++)) {
status =
(tmpc == '\n' ? lnewline() : linsert( 1, tmpc)) ;
/* Insertion error? */
if( status != TRUE)
return logger( status, FALSE, "%%Out of memory while inserting") ;
}
}
return status ;
}
/*
* 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.
*/
static int linsert_byte(int n, int c)
{
char *cp1;
char *cp2;
struct line *lp1;
struct line *lp2;
struct line *lp3;
int doto;
int i;
struct window *wp;
assert( (curbp->b_mode & MDVIEW) == 0) ;
#if 0
if (curbp->b_mode & MDVIEW) /* don't allow this command if */
return rdonly(); /* we are in read only mode */
#endif
lchange(WFEDIT);
lp1 = curwp->w_dotp; /* Current line */
if (lp1 == curbp->b_linep) { /* At the end: special */
if (curwp->w_doto != 0) {
logwrite( "bug: linsert") ;
return FALSE;
}
if ((lp2 = lalloc(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] = 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(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;
free((char *) lp1);
} 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] = 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;
}
int linsert(int n, int c)
{
char utf8[6];
int bytes, i ;
assert( n > 0) ;
if (curbp->b_mode & MDVIEW) /* don't allow this command if */
return rdonly(); /* we are in read only mode */
bytes = unicode_to_utf8(c, utf8) ;
if (bytes == 1)
return linsert_byte(n, (unsigned char) utf8[0]);
for (i = 0; i < n; i++) {
int j;
for (j = 0; j < bytes; j++) {
unsigned char c = utf8[j];
if (!linsert_byte(1, c))
return FALSE;
}
}
return TRUE;
}
/*
* Overwrite a character into the current line at the current position
*
* int c; character to overwrite on current position
*/
static int lowrite(int c)
{
if (curwp->w_doto < curwp->w_dotp->l_used &&
(lgetc(curwp->w_dotp, curwp->w_doto) != '\t' ||
((curwp->w_doto) & tabmask) == tabmask))
ldelchar(1, FALSE);
return linsert(1, c);
}
/*
* lover -- Overwrite a string at the current point
*/
int lover( char *ostr) {
int status = TRUE ;
if (ostr != NULL) {
char tmpc ;
while( (tmpc = *ostr++)) {
status =
(tmpc == '\n' ? lnewline() : lowrite(tmpc));
/* Insertion error? */
if( status != TRUE)
return logger( status, FALSE, "%%Out of memory while overwriting") ;
}
}
return status ;
}
/*
* 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.
*/
int lnewline(void)
{
char *cp1;
char *cp2;
struct line *lp1;
struct line *lp2;
int doto;
struct window *wp;
if (curbp->b_mode & MDVIEW) /* don't allow this command if */
return rdonly(); /* we are in read only mode */
#if SCROLLCODE
lchange(WFHARD | WFINS);
#else
lchange(WFHARD);
#endif
lp1 = curwp->w_dotp; /* Get the address and */
doto = curwp->w_doto; /* offset of "." */
if ((lp2 = lalloc(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;
}
int lgetchar(unicode_t *c)
{
int len = llength(curwp->w_dotp);
char *buf = curwp->w_dotp->l_text;
return utf8_to_unicode(buf, curwp->w_doto, len, c);
}
/*
* ldelete() really fundamentally works on bytes, not characters.
* It is used for things like "scan 5 words forwards, and remove
* the bytes we scanned".
*
* If you want to delete characters, use ldelchar().
*/
int ldelchar(long n, int kflag)
{
while (n-- > 0) {
unicode_t c;
if (!ldelete(lgetchar(&c), kflag))
return FALSE;
}
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.
*
* long n; # of chars to delete
* int kflag; put killed text in kill buffer flag
*/
int ldelete(long n, int kflag)
{
char *cp1;
char *cp2;
struct line *dotp;
int doto;
int chunk;
struct window *wp;
if (curbp->b_mode & MDVIEW) /* don't allow this command if */
return rdonly(); /* we are in read only mode */
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 > n)
chunk = n;
if (chunk == 0) { /* End of line, merge. */
#if SCROLLCODE
lchange(WFHARD | WFKILLS);
#else
lchange(WFHARD);
#endif
if (ldelnewline() == FALSE
|| (kflag != FALSE && kinsert('\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(*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;
}
/*
* getctext: grab and return a string with the text of
* the current line
*/
char *getctext(void)
{
struct line *lp; /* line to copy */
int size; /* length of line to return */
char *sp; /* string pointer into line */
char *dp; /* string pointer into returned line */
static char rline[NSTRING]; /* line to return */
/* find the contents of the current line and its length */
lp = curwp->w_dotp;
sp = lp->l_text;
size = lp->l_used;
if (size >= NSTRING)
size = NSTRING - 1;
/* copy it across */
dp = rline;
while (size--)
*dp++ = *sp++;
*dp = 0;
return rline;
}
/*
* 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.
*/
static int ldelnewline(void)
{
char *cp1;
char *cp2;
struct line *lp1;
struct line *lp2;
struct line *lp3;
struct window *wp;
assert( (curbp->b_mode & MDVIEW) == 0) ;
#if 0
if (curbp->b_mode & MDVIEW) /* don't allow this command if */
return rdonly(); /* we are in read only mode */
#endif
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(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;
free((char *) lp2);
return TRUE;
}
if ((lp3 = lalloc(lp1->l_used + lp2->l_used)) == NULL)
return FALSE;
cp1 = &lp1->l_text[0];
cp2 = &lp3->l_text[0];
while (cp1 != &lp1->l_text[lp1->l_used])
*cp2++ = *cp1++;
cp1 = &lp2->l_text[0];
while (cp1 != &lp2->l_text[lp2->l_used])
*cp2++ = *cp1++;
lp1->l_bp->l_fp = lp3;
lp3->l_fp = lp2->l_fp;
lp2->l_fp->l_bp = lp3;
lp3->l_bp = lp1->l_bp;
wp = wheadp;
while (wp != NULL) {
if (wp->w_linep == lp1 || wp->w_linep == lp2)
wp->w_linep = lp3;
if (wp->w_dotp == lp1)
wp->w_dotp = lp3;
else if (wp->w_dotp == lp2) {
wp->w_dotp = lp3;
wp->w_doto += lp1->l_used;
}
if (wp->w_markp == lp1)
wp->w_markp = lp3;
else if (wp->w_markp == lp2) {
wp->w_markp = lp3;
wp->w_marko += lp1->l_used;
}
wp = wp->w_wndp;
}
free((char *) lp1);
free((char *) lp2);
return TRUE;
}
/*
* Delete all of the text saved in the kill buffer. Called by commands when a
* new kill context is being created. The kill buffer array is released, just
* in case the buffer has grown to immense size. No errors.
*/
void kdelete(void)
{
struct kill *kp; /* ptr to scan kill buffer chunk list */
if (kbufh != NULL) {
/* first, delete all the chunks */
kbufp = kbufh;
while (kbufp != NULL) {
kp = kbufp->d_next;
free(kbufp);
kbufp = kp;
}
/* and reset all the kill buffer pointers */
kbufh = kbufp = NULL;
kused = KBLOCK;
}
}
/*
* Insert a character to the kill buffer, allocating new chunks as needed.
* Return TRUE if all is well, and FALSE on errors.
*
* int c; character to insert in the kill buffer
*/
int kinsert(int c)
{
struct kill *nchunk; /* ptr to newly malloced chunk */
/* check to see if we need a new chunk */
if (kused >= KBLOCK) {
if ((nchunk = (struct kill *)malloc(sizeof(struct kill))) == NULL)
return FALSE;
if (kbufh == NULL) /* set head ptr if first time */
kbufh = nchunk;
if (kbufp != NULL) /* point the current to this new one */
kbufp->d_next = nchunk;
kbufp = nchunk;
kbufp->d_next = NULL;
kused = 0;
}
/* and now insert the character */
kbufp->d_chunk[kused++] = c;
return TRUE;
}
/*
* Yank text back from the kill buffer. This is really easy. All of the work
* is done by the standard insert routines. All you do is run the loop, and
* check for errors. Bound to "C-Y".
*/
int yank(int f, int n)
{
int c;
int i;
char *sp; /* pointer into string to insert */
struct kill *kp; /* pointer into kill buffer */
if (curbp->b_mode & MDVIEW) /* don't allow this command if */
return rdonly(); /* we are in read only mode */
if (n < 0)
return FALSE;
/* make sure there is something to yank */
if (kbufh == NULL)
return TRUE; /* not an error, just nothing */
/* for each time.... */
while (n--) {
kp = kbufh;
while (kp != NULL) {
if (kp->d_next == NULL)
i = kused;
else
i = KBLOCK;
sp = kp->d_chunk;
while (i--) {
if ((c = *sp++) == '\n') {
if (lnewline() == FALSE)
return FALSE;
} else {
if (linsert_byte(1, c) == FALSE)
return FALSE;
}
}
kp = kp->d_next;
}
}
return TRUE;
}