Commit | Line | Data |
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c6953be1 | 1 | /* undo handling for GNU Emacs. |
0b5538bd | 2 | Copyright (C) 1990, 1993, 1994, 2000, 2002, 2003, 2004, |
aaef169d | 3 | 2005, 2006 Free Software Foundation, Inc. |
c6953be1 JB |
4 | |
5 | This file is part of GNU Emacs. | |
6 | ||
3b7ad313 EN |
7 | GNU Emacs is free software; you can redistribute it and/or modify |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2, or (at your option) | |
10 | any later version. | |
11 | ||
c6953be1 | 12 | GNU Emacs is distributed in the hope that it will be useful, |
3b7ad313 EN |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GNU Emacs; see the file COPYING. If not, write to | |
4fc5845f LK |
19 | the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
20 | Boston, MA 02110-1301, USA. */ | |
c6953be1 JB |
21 | |
22 | ||
18160b98 | 23 | #include <config.h> |
c6953be1 JB |
24 | #include "lisp.h" |
25 | #include "buffer.h" | |
4e665715 | 26 | #include "commands.h" |
91e25f5e | 27 | #include "window.h" |
c6953be1 | 28 | |
137e23ea RS |
29 | /* Limits controlling how much undo information to keep. */ |
30 | ||
31 | EMACS_INT undo_limit; | |
32 | EMACS_INT undo_strong_limit; | |
81c1cf71 RS |
33 | |
34 | Lisp_Object Vundo_outer_limit; | |
137e23ea RS |
35 | |
36 | /* Function to call when undo_outer_limit is exceeded. */ | |
37 | ||
38 | Lisp_Object Vundo_outer_limit_function; | |
39 | ||
c6953be1 JB |
40 | /* Last buffer for which undo information was recorded. */ |
41 | Lisp_Object last_undo_buffer; | |
42 | ||
f87a68b3 RS |
43 | Lisp_Object Qinhibit_read_only; |
44 | ||
49be18c9 KS |
45 | /* Marker for function call undo list elements. */ |
46 | ||
47 | Lisp_Object Qapply; | |
48 | ||
c58632fc RS |
49 | /* The first time a command records something for undo. |
50 | it also allocates the undo-boundary object | |
51 | which will be added to the list at the end of the command. | |
52 | This ensures we can't run out of space while trying to make | |
53 | an undo-boundary. */ | |
54 | Lisp_Object pending_boundary; | |
55 | ||
6396140a SM |
56 | /* Record point as it was at beginning of this command (if necessary) |
57 | And prepare the undo info for recording a change. | |
58 | PT is the position of point that will naturally occur as a result of the | |
59 | undo record that will be added just after this command terminates. */ | |
c6953be1 | 60 | |
6396140a SM |
61 | static void |
62 | record_point (pt) | |
f45bedd4 | 63 | int pt; |
c6953be1 | 64 | { |
6396140a | 65 | int at_boundary; |
bdbe6f28 | 66 | |
c58632fc RS |
67 | /* Allocate a cons cell to be the undo boundary after this command. */ |
68 | if (NILP (pending_boundary)) | |
69 | pending_boundary = Fcons (Qnil, Qnil); | |
70 | ||
8801a864 KR |
71 | if (!BUFFERP (last_undo_buffer) |
72 | || current_buffer != XBUFFER (last_undo_buffer)) | |
c6953be1 | 73 | Fundo_boundary (); |
552bdbcf | 74 | XSETBUFFER (last_undo_buffer, current_buffer); |
c6953be1 | 75 | |
6396140a SM |
76 | if (CONSP (current_buffer->undo_list)) |
77 | { | |
78 | /* Set AT_BOUNDARY to 1 only when we have nothing other than | |
79 | marker adjustment before undo boundary. */ | |
80 | ||
81 | Lisp_Object tail = current_buffer->undo_list, elt; | |
82 | ||
83 | while (1) | |
84 | { | |
85 | if (NILP (tail)) | |
86 | elt = Qnil; | |
87 | else | |
88 | elt = XCAR (tail); | |
89 | if (NILP (elt) || ! (CONSP (elt) && MARKERP (XCAR (elt)))) | |
90 | break; | |
91 | tail = XCDR (tail); | |
92 | } | |
93 | at_boundary = NILP (elt); | |
94 | } | |
95 | else | |
96 | at_boundary = 1; | |
97 | ||
ad9cdce4 | 98 | if (MODIFF <= SAVE_MODIFF) |
c6953be1 JB |
99 | record_first_change (); |
100 | ||
177c0ea7 | 101 | /* If we are just after an undo boundary, and |
6396140a SM |
102 | point wasn't at start of deleted range, record where it was. */ |
103 | if (at_boundary | |
6396140a | 104 | && BUFFERP (last_point_position_buffer) |
91e25f5e | 105 | /* If we're called from batch mode, this could be nil. */ |
6396140a | 106 | && current_buffer == XBUFFER (last_point_position_buffer)) |
91e25f5e RS |
107 | { |
108 | /* If we have switched windows, use the point value | |
109 | from the window we are in. */ | |
110 | if (! EQ (last_point_position_window, selected_window)) | |
111 | last_point_position = marker_position (XWINDOW (selected_window)->pointm); | |
112 | ||
113 | if (last_point_position != pt) | |
114 | current_buffer->undo_list | |
115 | = Fcons (make_number (last_point_position), current_buffer->undo_list); | |
116 | } | |
6396140a SM |
117 | } |
118 | ||
119 | /* Record an insertion that just happened or is about to happen, | |
120 | for LENGTH characters at position BEG. | |
121 | (It is possible to record an insertion before or after the fact | |
122 | because we don't need to record the contents.) */ | |
123 | ||
124 | void | |
125 | record_insert (beg, length) | |
126 | int beg, length; | |
127 | { | |
128 | Lisp_Object lbeg, lend; | |
129 | ||
130 | if (EQ (current_buffer->undo_list, Qt)) | |
131 | return; | |
132 | ||
133 | record_point (beg); | |
134 | ||
c6953be1 JB |
135 | /* If this is following another insertion and consecutive with it |
136 | in the buffer, combine the two. */ | |
38c0d37c | 137 | if (CONSP (current_buffer->undo_list)) |
c6953be1 JB |
138 | { |
139 | Lisp_Object elt; | |
c1d497be | 140 | elt = XCAR (current_buffer->undo_list); |
38c0d37c | 141 | if (CONSP (elt) |
c1d497be KR |
142 | && INTEGERP (XCAR (elt)) |
143 | && INTEGERP (XCDR (elt)) | |
144 | && XINT (XCDR (elt)) == beg) | |
c6953be1 | 145 | { |
f3fbd155 | 146 | XSETCDR (elt, make_number (beg + length)); |
c6953be1 JB |
147 | return; |
148 | } | |
149 | } | |
150 | ||
53480e99 KH |
151 | XSETFASTINT (lbeg, beg); |
152 | XSETINT (lend, beg + length); | |
213861c7 JB |
153 | current_buffer->undo_list = Fcons (Fcons (lbeg, lend), |
154 | current_buffer->undo_list); | |
c6953be1 JB |
155 | } |
156 | ||
157 | /* Record that a deletion is about to take place, | |
e928d437 | 158 | of the characters in STRING, at location BEG. */ |
c6953be1 | 159 | |
ff1aa840 | 160 | void |
e928d437 RS |
161 | record_delete (beg, string) |
162 | int beg; | |
163 | Lisp_Object string; | |
c6953be1 | 164 | { |
e928d437 | 165 | Lisp_Object sbeg; |
c6953be1 | 166 | |
bdbe6f28 RS |
167 | if (EQ (current_buffer->undo_list, Qt)) |
168 | return; | |
169 | ||
d5db4077 | 170 | if (PT == beg + SCHARS (string)) |
cbc1b668 | 171 | { |
6396140a SM |
172 | XSETINT (sbeg, -beg); |
173 | record_point (PT); | |
cbc1b668 KH |
174 | } |
175 | else | |
6396140a SM |
176 | { |
177 | XSETFASTINT (sbeg, beg); | |
178 | record_point (beg); | |
179 | } | |
350bce56 | 180 | |
c6953be1 | 181 | current_buffer->undo_list |
e928d437 | 182 | = Fcons (Fcons (string, sbeg), current_buffer->undo_list); |
c6953be1 JB |
183 | } |
184 | ||
714bced9 RS |
185 | /* Record the fact that MARKER is about to be adjusted by ADJUSTMENT. |
186 | This is done only when a marker points within text being deleted, | |
187 | because that's the only case where an automatic marker adjustment | |
188 | won't be inverted automatically by undoing the buffer modification. */ | |
189 | ||
ff1aa840 | 190 | void |
714bced9 RS |
191 | record_marker_adjustment (marker, adjustment) |
192 | Lisp_Object marker; | |
193 | int adjustment; | |
194 | { | |
195 | if (EQ (current_buffer->undo_list, Qt)) | |
196 | return; | |
197 | ||
198 | /* Allocate a cons cell to be the undo boundary after this command. */ | |
199 | if (NILP (pending_boundary)) | |
200 | pending_boundary = Fcons (Qnil, Qnil); | |
201 | ||
177c0ea7 | 202 | if (!BUFFERP (last_undo_buffer) |
2f33f38a | 203 | || current_buffer != XBUFFER (last_undo_buffer)) |
714bced9 RS |
204 | Fundo_boundary (); |
205 | XSETBUFFER (last_undo_buffer, current_buffer); | |
206 | ||
207 | current_buffer->undo_list | |
208 | = Fcons (Fcons (marker, make_number (adjustment)), | |
209 | current_buffer->undo_list); | |
210 | } | |
211 | ||
c6953be1 JB |
212 | /* Record that a replacement is about to take place, |
213 | for LENGTH characters at location BEG. | |
e928d437 | 214 | The replacement must not change the number of characters. */ |
c6953be1 | 215 | |
ff1aa840 | 216 | void |
c6953be1 JB |
217 | record_change (beg, length) |
218 | int beg, length; | |
219 | { | |
e928d437 | 220 | record_delete (beg, make_buffer_string (beg, beg + length, 1)); |
c6953be1 JB |
221 | record_insert (beg, length); |
222 | } | |
223 | \f | |
224 | /* Record that an unmodified buffer is about to be changed. | |
225 | Record the file modification date so that when undoing this entry | |
226 | we can tell whether it is obsolete because the file was saved again. */ | |
227 | ||
90dd3e4f | 228 | void |
c6953be1 JB |
229 | record_first_change () |
230 | { | |
231 | Lisp_Object high, low; | |
ad9cdce4 | 232 | struct buffer *base_buffer = current_buffer; |
0736cafe RS |
233 | |
234 | if (EQ (current_buffer->undo_list, Qt)) | |
235 | return; | |
236 | ||
2f33f38a GM |
237 | if (!BUFFERP (last_undo_buffer) |
238 | || current_buffer != XBUFFER (last_undo_buffer)) | |
0736cafe | 239 | Fundo_boundary (); |
552bdbcf | 240 | XSETBUFFER (last_undo_buffer, current_buffer); |
0736cafe | 241 | |
ad9cdce4 RS |
242 | if (base_buffer->base_buffer) |
243 | base_buffer = base_buffer->base_buffer; | |
244 | ||
245 | XSETFASTINT (high, (base_buffer->modtime >> 16) & 0xffff); | |
246 | XSETFASTINT (low, base_buffer->modtime & 0xffff); | |
c6953be1 JB |
247 | current_buffer->undo_list = Fcons (Fcons (Qt, Fcons (high, low)), current_buffer->undo_list); |
248 | } | |
249 | ||
da9319d5 RS |
250 | /* Record a change in property PROP (whose old value was VAL) |
251 | for LENGTH characters starting at position BEG in BUFFER. */ | |
252 | ||
90dd3e4f | 253 | void |
da9319d5 RS |
254 | record_property_change (beg, length, prop, value, buffer) |
255 | int beg, length; | |
256 | Lisp_Object prop, value, buffer; | |
257 | { | |
258 | Lisp_Object lbeg, lend, entry; | |
259 | struct buffer *obuf = current_buffer; | |
260 | int boundary = 0; | |
261 | ||
0736cafe | 262 | if (EQ (XBUFFER (buffer)->undo_list, Qt)) |
bdbe6f28 RS |
263 | return; |
264 | ||
c58632fc RS |
265 | /* Allocate a cons cell to be the undo boundary after this command. */ |
266 | if (NILP (pending_boundary)) | |
267 | pending_boundary = Fcons (Qnil, Qnil); | |
268 | ||
da9319d5 RS |
269 | if (!EQ (buffer, last_undo_buffer)) |
270 | boundary = 1; | |
271 | last_undo_buffer = buffer; | |
272 | ||
da9319d5 RS |
273 | /* Switch temporarily to the buffer that was changed. */ |
274 | current_buffer = XBUFFER (buffer); | |
275 | ||
276 | if (boundary) | |
277 | Fundo_boundary (); | |
278 | ||
ad9cdce4 | 279 | if (MODIFF <= SAVE_MODIFF) |
da9319d5 RS |
280 | record_first_change (); |
281 | ||
552bdbcf KH |
282 | XSETINT (lbeg, beg); |
283 | XSETINT (lend, beg + length); | |
da9319d5 RS |
284 | entry = Fcons (Qnil, Fcons (prop, Fcons (value, Fcons (lbeg, lend)))); |
285 | current_buffer->undo_list = Fcons (entry, current_buffer->undo_list); | |
286 | ||
287 | current_buffer = obuf; | |
288 | } | |
289 | ||
c6953be1 | 290 | DEFUN ("undo-boundary", Fundo_boundary, Sundo_boundary, 0, 0, 0, |
8c1a1077 PJ |
291 | doc: /* Mark a boundary between units of undo. |
292 | An undo command will stop at this point, | |
293 | but another undo command will undo to the previous boundary. */) | |
294 | () | |
c6953be1 JB |
295 | { |
296 | Lisp_Object tem; | |
297 | if (EQ (current_buffer->undo_list, Qt)) | |
298 | return Qnil; | |
299 | tem = Fcar (current_buffer->undo_list); | |
265a9e55 | 300 | if (!NILP (tem)) |
c58632fc RS |
301 | { |
302 | /* One way or another, cons nil onto the front of the undo list. */ | |
303 | if (!NILP (pending_boundary)) | |
304 | { | |
305 | /* If we have preallocated the cons cell to use here, | |
306 | use that one. */ | |
f3fbd155 | 307 | XSETCDR (pending_boundary, current_buffer->undo_list); |
c58632fc RS |
308 | current_buffer->undo_list = pending_boundary; |
309 | pending_boundary = Qnil; | |
310 | } | |
311 | else | |
312 | current_buffer->undo_list = Fcons (Qnil, current_buffer->undo_list); | |
313 | } | |
c6953be1 JB |
314 | return Qnil; |
315 | } | |
316 | ||
317 | /* At garbage collection time, make an undo list shorter at the end, | |
137e23ea RS |
318 | returning the truncated list. How this is done depends on the |
319 | variables undo-limit, undo-strong-limit and undo-outer-limit. | |
320 | In some cases this works by calling undo-outer-limit-function. */ | |
321 | ||
322 | void | |
323 | truncate_undo_list (b) | |
324 | struct buffer *b; | |
c6953be1 | 325 | { |
137e23ea | 326 | Lisp_Object list; |
c6953be1 JB |
327 | Lisp_Object prev, next, last_boundary; |
328 | int size_so_far = 0; | |
329 | ||
137e23ea RS |
330 | /* Make sure that calling undo-outer-limit-function |
331 | won't cause another GC. */ | |
332 | int count = inhibit_garbage_collection (); | |
333 | ||
334 | /* Make the buffer current to get its local values of variables such | |
335 | as undo_limit. Also so that Vundo_outer_limit_function can | |
336 | tell which buffer to operate on. */ | |
337 | record_unwind_protect (set_buffer_if_live, Fcurrent_buffer ()); | |
338 | set_buffer_internal (b); | |
339 | ||
340 | list = b->undo_list; | |
341 | ||
c6953be1 JB |
342 | prev = Qnil; |
343 | next = list; | |
344 | last_boundary = Qnil; | |
345 | ||
137e23ea | 346 | /* If the first element is an undo boundary, skip past it. */ |
c1d497be | 347 | if (CONSP (next) && NILP (XCAR (next))) |
c6953be1 JB |
348 | { |
349 | /* Add in the space occupied by this element and its chain link. */ | |
350 | size_so_far += sizeof (struct Lisp_Cons); | |
351 | ||
352 | /* Advance to next element. */ | |
353 | prev = next; | |
c1d497be | 354 | next = XCDR (next); |
c6953be1 | 355 | } |
e3d5ca1e | 356 | |
137e23ea RS |
357 | /* Always preserve at least the most recent undo record |
358 | unless it is really horribly big. | |
359 | ||
360 | Skip, skip, skip the undo, skip, skip, skip the undo, | |
361 | Skip, skip, skip the undo, skip to the undo bound'ry. */ | |
362 | ||
c1d497be | 363 | while (CONSP (next) && ! NILP (XCAR (next))) |
c6953be1 JB |
364 | { |
365 | Lisp_Object elt; | |
c1d497be | 366 | elt = XCAR (next); |
c6953be1 JB |
367 | |
368 | /* Add in the space occupied by this element and its chain link. */ | |
369 | size_so_far += sizeof (struct Lisp_Cons); | |
38c0d37c | 370 | if (CONSP (elt)) |
c6953be1 JB |
371 | { |
372 | size_so_far += sizeof (struct Lisp_Cons); | |
c1d497be | 373 | if (STRINGP (XCAR (elt))) |
c6953be1 | 374 | size_so_far += (sizeof (struct Lisp_String) - 1 |
d5db4077 | 375 | + SCHARS (XCAR (elt))); |
c6953be1 JB |
376 | } |
377 | ||
378 | /* Advance to next element. */ | |
379 | prev = next; | |
c1d497be | 380 | next = XCDR (next); |
c6953be1 | 381 | } |
e3d5ca1e | 382 | |
137e23ea RS |
383 | /* If by the first boundary we have already passed undo_outer_limit, |
384 | we're heading for memory full, so offer to clear out the list. */ | |
81c1cf71 RS |
385 | if (INTEGERP (Vundo_outer_limit) |
386 | && size_so_far > XINT (Vundo_outer_limit) | |
137e23ea RS |
387 | && !NILP (Vundo_outer_limit_function)) |
388 | { | |
88fde92a | 389 | Lisp_Object temp = last_undo_buffer, tem; |
137e23ea RS |
390 | |
391 | /* Normally the function this calls is undo-outer-limit-truncate. */ | |
88fde92a KR |
392 | tem = call1 (Vundo_outer_limit_function, make_number (size_so_far)); |
393 | if (! NILP (tem)) | |
137e23ea RS |
394 | { |
395 | /* The function is responsible for making | |
396 | any desired changes in buffer-undo-list. */ | |
397 | unbind_to (count, Qnil); | |
398 | return; | |
399 | } | |
400 | /* That function probably used the minibuffer, and if so, that | |
401 | changed last_undo_buffer. Change it back so that we don't | |
402 | force next change to make an undo boundary here. */ | |
403 | last_undo_buffer = temp; | |
404 | } | |
405 | ||
38c0d37c | 406 | if (CONSP (next)) |
c6953be1 JB |
407 | last_boundary = prev; |
408 | ||
137e23ea | 409 | /* Keep additional undo data, if it fits in the limits. */ |
38c0d37c | 410 | while (CONSP (next)) |
c6953be1 JB |
411 | { |
412 | Lisp_Object elt; | |
c1d497be | 413 | elt = XCAR (next); |
c6953be1 JB |
414 | |
415 | /* When we get to a boundary, decide whether to truncate | |
137e23ea | 416 | either before or after it. The lower threshold, undo_limit, |
c6953be1 | 417 | tells us to truncate after it. If its size pushes past |
137e23ea | 418 | the higher threshold undo_strong_limit, we truncate before it. */ |
265a9e55 | 419 | if (NILP (elt)) |
c6953be1 | 420 | { |
137e23ea | 421 | if (size_so_far > undo_strong_limit) |
c6953be1 JB |
422 | break; |
423 | last_boundary = prev; | |
137e23ea | 424 | if (size_so_far > undo_limit) |
c6953be1 JB |
425 | break; |
426 | } | |
427 | ||
428 | /* Add in the space occupied by this element and its chain link. */ | |
429 | size_so_far += sizeof (struct Lisp_Cons); | |
38c0d37c | 430 | if (CONSP (elt)) |
c6953be1 JB |
431 | { |
432 | size_so_far += sizeof (struct Lisp_Cons); | |
c1d497be | 433 | if (STRINGP (XCAR (elt))) |
c6953be1 | 434 | size_so_far += (sizeof (struct Lisp_String) - 1 |
d5db4077 | 435 | + SCHARS (XCAR (elt))); |
c6953be1 JB |
436 | } |
437 | ||
438 | /* Advance to next element. */ | |
439 | prev = next; | |
c1d497be | 440 | next = XCDR (next); |
c6953be1 JB |
441 | } |
442 | ||
443 | /* If we scanned the whole list, it is short enough; don't change it. */ | |
265a9e55 | 444 | if (NILP (next)) |
137e23ea | 445 | ; |
c6953be1 | 446 | /* Truncate at the boundary where we decided to truncate. */ |
137e23ea RS |
447 | else if (!NILP (last_boundary)) |
448 | XSETCDR (last_boundary, Qnil); | |
449 | /* There's nothing we decided to keep, so clear it out. */ | |
c6953be1 | 450 | else |
137e23ea RS |
451 | b->undo_list = Qnil; |
452 | ||
453 | unbind_to (count, Qnil); | |
c6953be1 JB |
454 | } |
455 | \f | |
456 | DEFUN ("primitive-undo", Fprimitive_undo, Sprimitive_undo, 2, 2, 0, | |
8c1a1077 PJ |
457 | doc: /* Undo N records from the front of the list LIST. |
458 | Return what remains of the list. */) | |
459 | (n, list) | |
063fb61f | 460 | Lisp_Object n, list; |
c6953be1 | 461 | { |
de65837b KH |
462 | struct gcpro gcpro1, gcpro2; |
463 | Lisp_Object next; | |
331379bf | 464 | int count = SPECPDL_INDEX (); |
de65837b | 465 | register int arg; |
4ac03187 KS |
466 | Lisp_Object oldlist; |
467 | int did_apply = 0; | |
177c0ea7 | 468 | |
c6953be1 JB |
469 | #if 0 /* This is a good feature, but would make undo-start |
470 | unable to do what is expected. */ | |
471 | Lisp_Object tem; | |
472 | ||
473 | /* If the head of the list is a boundary, it is the boundary | |
474 | preceding this command. Get rid of it and don't count it. */ | |
475 | tem = Fcar (list); | |
265a9e55 | 476 | if (NILP (tem)) |
c6953be1 JB |
477 | list = Fcdr (list); |
478 | #endif | |
479 | ||
b7826503 | 480 | CHECK_NUMBER (n); |
de65837b KH |
481 | arg = XINT (n); |
482 | next = Qnil; | |
483 | GCPRO2 (next, list); | |
4ac03187 KS |
484 | /* I don't think we need to gcpro oldlist, as we use it only |
485 | to check for EQ. ++kfs */ | |
de65837b | 486 | |
38d56be3 GM |
487 | /* In a writable buffer, enable undoing read-only text that is so |
488 | because of text properties. */ | |
489 | if (NILP (current_buffer->read_only)) | |
f87a68b3 RS |
490 | specbind (Qinhibit_read_only, Qt); |
491 | ||
8c757fd7 GM |
492 | /* Don't let `intangible' properties interfere with undo. */ |
493 | specbind (Qinhibit_point_motion_hooks, Qt); | |
494 | ||
4ac03187 KS |
495 | oldlist = current_buffer->undo_list; |
496 | ||
c6953be1 JB |
497 | while (arg > 0) |
498 | { | |
c3b09bbf | 499 | while (CONSP (list)) |
c6953be1 | 500 | { |
c3b09bbf SM |
501 | next = XCAR (list); |
502 | list = XCDR (list); | |
350bce56 | 503 | /* Exit inner loop at undo boundary. */ |
265a9e55 | 504 | if (NILP (next)) |
c6953be1 | 505 | break; |
350bce56 | 506 | /* Handle an integer by setting point to that value. */ |
38c0d37c | 507 | if (INTEGERP (next)) |
350bce56 | 508 | SET_PT (clip_to_bounds (BEGV, XINT (next), ZV)); |
38c0d37c | 509 | else if (CONSP (next)) |
c6953be1 | 510 | { |
350bce56 RS |
511 | Lisp_Object car, cdr; |
512 | ||
c3b09bbf SM |
513 | car = XCAR (next); |
514 | cdr = XCDR (next); | |
350bce56 | 515 | if (EQ (car, Qt)) |
c6953be1 | 516 | { |
350bce56 RS |
517 | /* Element (t high . low) records previous modtime. */ |
518 | Lisp_Object high, low; | |
519 | int mod_time; | |
ad9cdce4 | 520 | struct buffer *base_buffer = current_buffer; |
350bce56 RS |
521 | |
522 | high = Fcar (cdr); | |
523 | low = Fcdr (cdr); | |
d8552b2f | 524 | mod_time = (XFASTINT (high) << 16) + XFASTINT (low); |
ad9cdce4 RS |
525 | |
526 | if (current_buffer->base_buffer) | |
527 | base_buffer = current_buffer->base_buffer; | |
528 | ||
350bce56 RS |
529 | /* If this records an obsolete save |
530 | (not matching the actual disk file) | |
531 | then don't mark unmodified. */ | |
ad9cdce4 | 532 | if (mod_time != base_buffer->modtime) |
103dcb38 | 533 | continue; |
e6dd6080 | 534 | #ifdef CLASH_DETECTION |
350bce56 | 535 | Funlock_buffer (); |
e6dd6080 | 536 | #endif /* CLASH_DETECTION */ |
350bce56 | 537 | Fset_buffer_modified_p (Qnil); |
c6953be1 | 538 | } |
d8552b2f | 539 | else if (EQ (car, Qnil)) |
da9319d5 | 540 | { |
6887bce5 | 541 | /* Element (nil PROP VAL BEG . END) is property change. */ |
da9319d5 RS |
542 | Lisp_Object beg, end, prop, val; |
543 | ||
544 | prop = Fcar (cdr); | |
545 | cdr = Fcdr (cdr); | |
546 | val = Fcar (cdr); | |
547 | cdr = Fcdr (cdr); | |
548 | beg = Fcar (cdr); | |
549 | end = Fcdr (cdr); | |
550 | ||
551 | Fput_text_property (beg, end, prop, val, Qnil); | |
552 | } | |
38c0d37c | 553 | else if (INTEGERP (car) && INTEGERP (cdr)) |
c6953be1 | 554 | { |
350bce56 | 555 | /* Element (BEG . END) means range was inserted. */ |
350bce56 RS |
556 | |
557 | if (XINT (car) < BEGV | |
558 | || XINT (cdr) > ZV) | |
c6953be1 | 559 | error ("Changes to be undone are outside visible portion of buffer"); |
f28f04cc RS |
560 | /* Set point first thing, so that undoing this undo |
561 | does not send point back to where it is now. */ | |
350bce56 | 562 | Fgoto_char (car); |
f28f04cc | 563 | Fdelete_region (car, cdr); |
350bce56 | 564 | } |
49be18c9 | 565 | else if (EQ (car, Qapply)) |
6887bce5 | 566 | { |
3419757d | 567 | /* Element (apply FUN . ARGS) means call FUN to undo. */ |
a7a39468 KS |
568 | struct buffer *save_buffer = current_buffer; |
569 | ||
49be18c9 | 570 | car = Fcar (cdr); |
3419757d | 571 | cdr = Fcdr (cdr); |
49be18c9 KS |
572 | if (INTEGERP (car)) |
573 | { | |
3419757d SM |
574 | /* Long format: (apply DELTA START END FUN . ARGS). */ |
575 | Lisp_Object delta = car; | |
576 | Lisp_Object start = Fcar (cdr); | |
577 | Lisp_Object end = Fcar (Fcdr (cdr)); | |
578 | Lisp_Object start_mark = Fcopy_marker (start, Qnil); | |
579 | Lisp_Object end_mark = Fcopy_marker (end, Qt); | |
580 | ||
581 | cdr = Fcdr (Fcdr (cdr)); | |
582 | apply1 (Fcar (cdr), Fcdr (cdr)); | |
583 | ||
584 | /* Check that the function did what the entry said it | |
585 | would do. */ | |
586 | if (!EQ (start, Fmarker_position (start_mark)) | |
587 | || (XINT (delta) + XINT (end) | |
588 | != marker_position (end_mark))) | |
589 | error ("Changes to be undone by function different than announced"); | |
590 | Fset_marker (start_mark, Qnil, Qnil); | |
591 | Fset_marker (end_mark, Qnil, Qnil); | |
49be18c9 | 592 | } |
3419757d SM |
593 | else |
594 | apply1 (car, cdr); | |
a7a39468 KS |
595 | |
596 | if (save_buffer != current_buffer) | |
597 | error ("Undo function switched buffer"); | |
4ac03187 | 598 | did_apply = 1; |
6887bce5 | 599 | } |
38c0d37c | 600 | else if (STRINGP (car) && INTEGERP (cdr)) |
350bce56 RS |
601 | { |
602 | /* Element (STRING . POS) means STRING was deleted. */ | |
603 | Lisp_Object membuf; | |
604 | int pos = XINT (cdr); | |
605 | ||
606 | membuf = car; | |
607 | if (pos < 0) | |
608 | { | |
609 | if (-pos < BEGV || -pos > ZV) | |
610 | error ("Changes to be undone are outside visible portion of buffer"); | |
611 | SET_PT (-pos); | |
612 | Finsert (1, &membuf); | |
613 | } | |
614 | else | |
615 | { | |
616 | if (pos < BEGV || pos > ZV) | |
617 | error ("Changes to be undone are outside visible portion of buffer"); | |
618 | SET_PT (pos); | |
619 | ||
b2adc409 RS |
620 | /* Now that we record marker adjustments |
621 | (caused by deletion) for undo, | |
622 | we should always insert after markers, | |
623 | so that undoing the marker adjustments | |
624 | put the markers back in the right place. */ | |
625 | Finsert (1, &membuf); | |
350bce56 RS |
626 | SET_PT (pos); |
627 | } | |
c6953be1 | 628 | } |
714bced9 RS |
629 | else if (MARKERP (car) && INTEGERP (cdr)) |
630 | { | |
631 | /* (MARKER . INTEGER) means a marker MARKER | |
632 | was adjusted by INTEGER. */ | |
633 | if (XMARKER (car)->buffer) | |
634 | Fset_marker (car, | |
635 | make_number (marker_position (car) - XINT (cdr)), | |
636 | Fmarker_buffer (car)); | |
637 | } | |
c6953be1 JB |
638 | } |
639 | } | |
640 | arg--; | |
641 | } | |
642 | ||
4ac03187 KS |
643 | |
644 | /* Make sure an apply entry produces at least one undo entry, | |
645 | so the test in `undo' for continuing an undo series | |
646 | will work right. */ | |
647 | if (did_apply | |
648 | && EQ (oldlist, current_buffer->undo_list)) | |
649 | current_buffer->undo_list | |
650 | = Fcons (list3 (Qapply, Qcdr, Qnil), current_buffer->undo_list); | |
651 | ||
de65837b | 652 | UNGCPRO; |
f87a68b3 | 653 | return unbind_to (count, list); |
c6953be1 | 654 | } |
6887bce5 | 655 | \f |
dfcf069d | 656 | void |
c6953be1 JB |
657 | syms_of_undo () |
658 | { | |
f87a68b3 RS |
659 | Qinhibit_read_only = intern ("inhibit-read-only"); |
660 | staticpro (&Qinhibit_read_only); | |
661 | ||
49be18c9 KS |
662 | Qapply = intern ("apply"); |
663 | staticpro (&Qapply); | |
664 | ||
c58632fc RS |
665 | pending_boundary = Qnil; |
666 | staticpro (&pending_boundary); | |
667 | ||
c6953be1 JB |
668 | defsubr (&Sprimitive_undo); |
669 | defsubr (&Sundo_boundary); | |
137e23ea RS |
670 | |
671 | DEFVAR_INT ("undo-limit", &undo_limit, | |
672 | doc: /* Keep no more undo information once it exceeds this size. | |
673 | This limit is applied when garbage collection happens. | |
674 | When a previous command increases the total undo list size past this | |
675 | value, the earlier commands that came before it are forgotten. | |
676 | ||
677 | The size is counted as the number of bytes occupied, | |
678 | which includes both saved text and other data. */); | |
679 | undo_limit = 20000; | |
680 | ||
681 | DEFVAR_INT ("undo-strong-limit", &undo_strong_limit, | |
682 | doc: /* Don't keep more than this much size of undo information. | |
683 | This limit is applied when garbage collection happens. | |
684 | When a previous command increases the total undo list size past this | |
685 | value, that command and the earlier commands that came before it are forgotten. | |
686 | However, the most recent buffer-modifying command's undo info | |
687 | is never discarded for this reason. | |
688 | ||
689 | The size is counted as the number of bytes occupied, | |
690 | which includes both saved text and other data. */); | |
691 | undo_strong_limit = 30000; | |
692 | ||
81c1cf71 | 693 | DEFVAR_LISP ("undo-outer-limit", &Vundo_outer_limit, |
137e23ea RS |
694 | doc: /* Outer limit on size of undo information for one command. |
695 | At garbage collection time, if the current command has produced | |
62d776fd LT |
696 | more than this much undo information, it discards the info and displays |
697 | a warning. This is a last-ditch limit to prevent memory overflow. | |
137e23ea | 698 | |
62d776fd LT |
699 | The size is counted as the number of bytes occupied, which includes |
700 | both saved text and other data. A value of nil means no limit. In | |
701 | this case, accumulating one huge undo entry could make Emacs crash as | |
702 | a result of memory overflow. | |
137e23ea RS |
703 | |
704 | In fact, this calls the function which is the value of | |
705 | `undo-outer-limit-function' with one argument, the size. | |
706 | The text above describes the behavior of the function | |
707 | that variable usually specifies. */); | |
6de38aa3 | 708 | Vundo_outer_limit = make_number (3000000); |
137e23ea RS |
709 | |
710 | DEFVAR_LISP ("undo-outer-limit-function", &Vundo_outer_limit_function, | |
711 | doc: /* Function to call when an undo list exceeds `undo-outer-limit'. | |
712 | This function is called with one argument, the current undo list size | |
713 | for the most recent command (since the last undo boundary). | |
714 | If the function returns t, that means truncation has been fully handled. | |
715 | If it returns nil, the other forms of truncation are done. | |
716 | ||
717 | Garbage collection is inhibited around the call to this function, | |
718 | so it must make sure not to do a lot of consing. */); | |
719 | Vundo_outer_limit_function = Qnil; | |
c6953be1 | 720 | } |
ab5796a9 MB |
721 | |
722 | /* arch-tag: d546ee01-4aed-4ffb-bb8b-eefaae50d38a | |
723 | (do not change this comment) */ |