1 /* Buffer insertion/deletion and gap motion for GNU Emacs.
2 Copyright (C) 1985, 1986, 1993 Free Software Foundation, Inc.
4 This file is part of GNU Emacs.
6 GNU Emacs is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 1, or (at your option)
11 GNU Emacs is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU Emacs; see the file COPYING. If not, write to
18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
23 #include "intervals.h"
26 #include "blockinput.h"
28 /* Move gap to position `pos'.
29 Note that this can quit! */
40 /* Move the gap to POS, which is less than the current GPT.
41 If NEWGAP is nonzero, then don't update beg_unchanged and end_unchanged. */
43 gap_left (pos
, newgap
)
47 register unsigned char *to
, *from
;
55 if (unchanged_modified
== MODIFF
)
58 end_unchanged
= Z
- pos
- 1;
62 if (Z
- GPT
< end_unchanged
)
63 end_unchanged
= Z
- GPT
;
64 if (pos
< beg_unchanged
)
74 /* Now copy the characters. To move the gap down,
75 copy characters up. */
79 /* I gets number of characters left to copy. */
83 /* If a quit is requested, stop copying now.
84 Change POS to be where we have actually moved the gap to. */
90 /* Move at most 32000 chars before checking again for a quit. */
95 /* bcopy is safe if the two areas of memory do not overlap
96 or on systems where bcopy is always safe for moving upward. */
100 /* If overlap is not safe, avoid it by not moving too many
101 characters at once. */
102 if (!BCOPY_UPWARD_SAFE
&& i
> to
- from
)
117 /* Adjust markers, and buffer data structure, to put the gap at POS.
118 POS is where the loop above stopped, which may be what was specified
119 or may be where a quit was detected. */
120 adjust_markers (pos
+ 1, GPT
, GAP_SIZE
);
128 register unsigned char *to
, *from
;
134 if (unchanged_modified
== MODIFF
)
137 end_unchanged
= Z
- pos
- 1;
141 if (Z
- pos
- 1 < end_unchanged
)
142 end_unchanged
= Z
- pos
- 1;
143 if (GPT
- BEG
< beg_unchanged
)
144 beg_unchanged
= GPT
- BEG
;
152 /* Now copy the characters. To move the gap up,
153 copy characters down. */
157 /* I gets number of characters left to copy. */
161 /* If a quit is requested, stop copying now.
162 Change POS to be where we have actually moved the gap to. */
168 /* Move at most 32000 chars before checking again for a quit. */
173 /* bcopy is safe if the two areas of memory do not overlap
174 or on systems where bcopy is always safe for moving downward. */
175 && (BCOPY_DOWNWARD_SAFE
176 || from
- to
>= 128))
178 /* If overlap is not safe, avoid it by not moving too many
179 characters at once. */
180 if (!BCOPY_DOWNWARD_SAFE
&& i
> from
- to
)
195 adjust_markers (GPT
+ GAP_SIZE
, pos
+ 1 + GAP_SIZE
, - GAP_SIZE
);
200 /* Add `amount' to the position of every marker in the current buffer
201 whose current position is between `from' (exclusive) and `to' (inclusive).
202 Also, any markers past the outside of that interval, in the direction
203 of adjustment, are first moved back to the near end of the interval
204 and then adjusted by `amount'. */
206 adjust_markers (from
, to
, amount
)
207 register int from
, to
, amount
;
210 register struct Lisp_Marker
*m
;
213 marker
= current_buffer
->markers
;
215 while (!NILP (marker
))
217 m
= XMARKER (marker
);
221 if (mpos
> to
&& mpos
< to
+ amount
)
226 if (mpos
> from
+ amount
&& mpos
<= from
)
227 mpos
= from
+ amount
;
229 if (mpos
> from
&& mpos
<= to
)
236 /* Make the gap INCREMENT characters longer. */
241 unsigned char *result
;
246 /* If we have to get more space, get enough to last a while. */
250 result
= BUFFER_REALLOC (BEG_ADDR
, (Z
- BEG
+ GAP_SIZE
+ increment
));
257 /* Prevent quitting in move_gap. */
262 old_gap_size
= GAP_SIZE
;
264 /* Call the newly allocated space a gap at the end of the whole space. */
266 GAP_SIZE
= increment
;
268 /* Move the new gap down to be consecutive with the end of the old one.
269 This adjusts the markers properly too. */
270 gap_left (real_gap_loc
+ old_gap_size
, 1);
272 /* Now combine the two into one large gap. */
273 GAP_SIZE
+= old_gap_size
;
279 /* Insert a string of specified length before point.
280 DO NOT use this for the contents of a Lisp string!
281 prepare_to_modify_buffer could relocate the string. */
283 insert (string
, length
)
284 register unsigned char *string
;
287 register Lisp_Object temp
;
292 /* Make sure point-max won't overflow after this insertion. */
293 XSET (temp
, Lisp_Int
, length
+ Z
);
294 if (length
+ Z
!= XINT (temp
))
295 error ("maximum buffer size exceeded");
297 prepare_to_modify_buffer (point
, point
);
301 if (GAP_SIZE
< length
)
302 make_gap (length
- GAP_SIZE
);
304 record_insert (point
, length
);
307 bcopy (string
, GPT_ADDR
, length
);
309 /* Only defined if Emacs is compiled with USE_TEXT_PROPERTIES */
310 offset_intervals (current_buffer
, point
, length
);
316 SET_PT (point
+ length
);
318 signal_after_change (point
-length
, 0, length
);
321 /* Insert the part of the text of STRING, a Lisp object assumed to be
322 of type string, consisting of the LENGTH characters starting at
323 position POS. If the text of STRING has properties, they are absorbed
326 It does not work to use `insert' for this, because a GC could happen
327 before we bcopy the stuff into the buffer, and relocate the string
328 without insert noticing. */
330 insert_from_string (string
, pos
, length
)
332 register int pos
, length
;
334 register Lisp_Object temp
;
340 /* Make sure point-max won't overflow after this insertion. */
341 XSET (temp
, Lisp_Int
, length
+ Z
);
342 if (length
+ Z
!= XINT (temp
))
343 error ("maximum buffer size exceeded");
346 prepare_to_modify_buffer (point
, point
);
350 if (GAP_SIZE
< length
)
351 make_gap (length
- GAP_SIZE
);
353 record_insert (point
, length
);
357 bcopy (XSTRING (string
)->data
, GPT_ADDR
, length
);
359 /* Only defined if Emacs is compiled with USE_TEXT_PROPERTIES */
360 offset_intervals (current_buffer
, point
, length
);
367 /* Only defined if Emacs is compiled with USE_TEXT_PROPERTIES */
368 graft_intervals_into_buffer (XSTRING (string
)->intervals
, point
,
371 SET_PT (point
+ length
);
373 signal_after_change (point
-length
, 0, length
);
376 /* Insert the character C before point */
385 /* Insert the null-terminated string S before point */
391 insert (s
, strlen (s
));
394 /* Like `insert' except that all markers pointing at the place where
395 the insertion happens are adjusted to point after it.
396 Don't use this function to insert part of a Lisp string,
397 since gc could happen and relocate it. */
399 insert_before_markers (string
, length
)
400 unsigned char *string
;
403 register int opoint
= point
;
404 insert (string
, length
);
405 adjust_markers (opoint
- 1, opoint
, length
);
408 /* Insert part of a Lisp string, relocating markers after. */
410 insert_from_string_before_markers (string
, pos
, length
)
412 register int pos
, length
;
414 register int opoint
= point
;
415 insert_from_string (string
, pos
, length
);
416 adjust_markers (opoint
- 1, opoint
, length
);
419 /* Delete characters in current buffer
420 from FROM up to (but not including) TO. */
423 register int from
, to
;
427 /* Make args be valid */
433 if ((numdel
= to
- from
) <= 0)
436 /* Make sure the gap is somewhere in or next to what we are deleting. */
442 prepare_to_modify_buffer (from
, to
);
444 record_delete (from
, numdel
);
447 /* Relocate point as if it were a marker. */
453 SET_PT (point
- numdel
);
456 /* Only defined if Emacs is compiled with USE_TEXT_PROPERTIES */
457 offset_intervals (current_buffer
, point
, - numdel
);
459 /* Relocate all markers pointing into the new, larger gap
460 to point at the end of the text before the gap. */
461 adjust_markers (to
+ GAP_SIZE
, to
+ GAP_SIZE
, - numdel
- GAP_SIZE
);
468 if (GPT
- BEG
< beg_unchanged
)
469 beg_unchanged
= GPT
- BEG
;
470 if (Z
- GPT
< end_unchanged
)
471 end_unchanged
= Z
- GPT
;
473 signal_after_change (from
, numdel
, 0);
476 /* Call this if you're about to change the region of BUFFER from START
477 to END. This checks the read-only properties of the region, calls
478 the necessary modification hooks, and warns the next redisplay that
479 it should pay attention to that area. */
480 modify_region (buffer
, start
, end
)
481 struct buffer
*buffer
;
484 struct buffer
*old_buffer
= current_buffer
;
486 if (buffer
!= old_buffer
)
487 set_buffer_internal (buffer
);
489 prepare_to_modify_buffer (start
, end
);
491 if (start
- 1 < beg_unchanged
|| unchanged_modified
== MODIFF
)
492 beg_unchanged
= start
- 1;
493 if (Z
- end
< end_unchanged
494 || unchanged_modified
== MODIFF
)
495 end_unchanged
= Z
- end
;
498 if (buffer
!= old_buffer
)
499 set_buffer_internal (old_buffer
);
502 /* Check that it is okay to modify the buffer between START and END.
503 Run the before-change-function, if any. If intervals are in use,
504 verify that the text to be modified is not read-only, and call
505 any modification properties the text may have. */
507 prepare_to_modify_buffer (start
, end
)
508 Lisp_Object start
, end
;
510 if (!NILP (current_buffer
->read_only
))
511 Fbarf_if_buffer_read_only ();
513 /* Only defined if Emacs is compiled with USE_TEXT_PROPERTIES */
514 verify_interval_modification (current_buffer
, start
, end
);
516 verify_overlay_modification (start
, end
);
518 #ifdef CLASH_DETECTION
519 if (!NILP (current_buffer
->filename
)
520 && current_buffer
->save_modified
>= MODIFF
)
521 lock_file (current_buffer
->filename
);
523 /* At least warn if this file has changed on disk since it was visited. */
524 if (!NILP (current_buffer
->filename
)
525 && current_buffer
->save_modified
>= MODIFF
526 && NILP (Fverify_visited_file_modtime (Fcurrent_buffer ()))
527 && !NILP (Ffile_exists_p (current_buffer
->filename
)))
528 call1 (intern ("ask-user-about-supersession-threat"),
529 current_buffer
->filename
);
530 #endif /* not CLASH_DETECTION */
532 signal_before_change (start
, end
);
534 Vdeactivate_mark
= Qt
;
538 before_change_function_restore (value
)
541 Vbefore_change_function
= value
;
545 after_change_function_restore (value
)
548 Vafter_change_function
= value
;
551 /* Signal a change to the buffer immediately before it happens.
552 START and END are the bounds of the text to be changed,
555 signal_before_change (start
, end
)
556 Lisp_Object start
, end
;
558 /* If buffer is unmodified, run a special hook for that case. */
559 if (current_buffer
->save_modified
>= MODIFF
560 && !NILP (Vfirst_change_hook
)
561 && !NILP (Vrun_hooks
))
562 call1 (Vrun_hooks
, Qfirst_change_hook
);
564 /* Now in any case run the before-change-function if any. */
565 if (!NILP (Vbefore_change_function
))
567 int count
= specpdl_ptr
- specpdl
;
568 Lisp_Object function
;
570 function
= Vbefore_change_function
;
571 record_unwind_protect (after_change_function_restore
,
572 Vafter_change_function
);
573 record_unwind_protect (before_change_function_restore
,
574 Vbefore_change_function
);
575 Vafter_change_function
= Qnil
;
576 Vbefore_change_function
= Qnil
;
578 call2 (function
, start
, end
);
579 unbind_to (count
, Qnil
);
583 /* Signal a change immediately after it happens.
584 POS is the address of the start of the changed text.
585 LENDEL is the number of characters of the text before the change.
586 (Not the whole buffer; just the part that was changed.)
587 LENINS is the number of characters in the changed text. */
589 signal_after_change (pos
, lendel
, lenins
)
590 int pos
, lendel
, lenins
;
592 if (!NILP (Vafter_change_function
))
594 int count
= specpdl_ptr
- specpdl
;
595 Lisp_Object function
;
596 function
= Vafter_change_function
;
598 record_unwind_protect (after_change_function_restore
,
599 Vafter_change_function
);
600 record_unwind_protect (before_change_function_restore
,
601 Vbefore_change_function
);
602 Vafter_change_function
= Qnil
;
603 Vbefore_change_function
= Qnil
;
605 call3 (function
, make_number (pos
), make_number (pos
+ lenins
),
606 make_number (lendel
));
607 unbind_to (count
, Qnil
);