428
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1 /* undo handling for XEmacs.
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2 Copyright (C) 1990, 1992, 1993, 1994 Free Software Foundation, Inc.
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3
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4 This file is part of XEmacs.
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5
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6 XEmacs is free software; you can redistribute it and/or modify it
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7 under the terms of the GNU General Public License as published by the
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8 Free Software Foundation; either version 2, or (at your option) any
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9 later version.
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10
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11 XEmacs is distributed in the hope that it will be useful, but WITHOUT
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12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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14 for more details.
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15
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16 You should have received a copy of the GNU General Public License
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17 along with XEmacs; see the file COPYING. If not, write to
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18 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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19 Boston, MA 02111-1307, USA. */
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20
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21 /* Synched up with: FSF 19.28. */
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22
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23 /* This file has been Mule-ized. */
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24
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25 #include <config.h>
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26 #include "lisp.h"
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27 #include "buffer.h"
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28 #include "extents.h"
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29
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30 /* Maintained in event-stream.c */
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665
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31 extern Charbpos last_point_position;
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428
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32 extern Lisp_Object last_point_position_buffer;
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33
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34 /* Extent code needs to know about undo because the behavior of insert()
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35 with regard to extents varies depending on whether we are inside
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36 an undo or not. */
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37 int inside_undo;
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38
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39 /* Last buffer for which undo information was recorded. */
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40 static Lisp_Object last_undo_buffer;
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41
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42 Lisp_Object Qinhibit_read_only;
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43
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44 /* The first time a command records something for undo.
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45 it also allocates the undo-boundary object
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46 which will be added to the list at the end of the command.
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47 This ensures we can't run out of space while trying to make
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48 an undo-boundary. */
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49 static Lisp_Object pending_boundary;
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50
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51 static void
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52 undo_boundary (struct buffer *b)
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53 {
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54 Lisp_Object tem = Fcar (b->undo_list);
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55 if (!NILP (tem))
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56 {
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57 /* One way or another, cons nil onto the front of the undo list. */
|
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58 if (CONSP (pending_boundary))
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59 {
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60 /* If we have preallocated the cons cell to use here,
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61 use that one. */
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62 XCDR (pending_boundary) = b->undo_list;
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63 b->undo_list = pending_boundary;
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64 pending_boundary = Qnil;
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65 }
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66 else
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67 b->undo_list = Fcons (Qnil, b->undo_list);
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68 }
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69 }
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70
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71
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72 static int
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73 undo_prelude (struct buffer *b, int hack_pending_boundary)
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74 {
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75 if (EQ (b->undo_list, Qt))
|
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76 return (0);
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77
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78 if (NILP (last_undo_buffer)
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79 || (BUFFER_BASE_BUFFER (b)
|
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80 != BUFFER_BASE_BUFFER (XBUFFER (last_undo_buffer))))
|
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81 {
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82 undo_boundary (b);
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793
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83 last_undo_buffer = wrap_buffer (b);
|
428
|
84 }
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85
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86 /* Allocate a cons cell to be the undo boundary after this command. */
|
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87 if (hack_pending_boundary && NILP (pending_boundary))
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88 pending_boundary = Fcons (Qnil, Qnil);
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89
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90 if (BUF_MODIFF (b) <= BUF_SAVE_MODIFF (b))
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91 {
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92 /* Record that an unmodified buffer is about to be changed.
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93 Record the file modification date so that when undoing this
|
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94 entry we can tell whether it is obsolete because the file was
|
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95 saved again. */
|
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96 b->undo_list
|
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97 = Fcons (Fcons (Qt,
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98 Fcons (make_int ((b->modtime >> 16) & 0xffff),
|
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99 make_int (b->modtime & 0xffff))),
|
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100 b->undo_list);
|
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101 }
|
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102 return 1;
|
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103 }
|
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104
|
|
105
|
|
106
|
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107 /* Record an insertion that just happened or is about to happen,
|
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108 for LENGTH characters at position BEG.
|
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109 (It is possible to record an insertion before or after the fact
|
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110 because we don't need to record the contents.) */
|
|
111
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|
112 void
|
665
|
113 record_insert (struct buffer *b, Charbpos beg, Charcount length)
|
428
|
114 {
|
|
115 if (!undo_prelude (b, 1))
|
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116 return;
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|
117
|
|
118 /* If this is following another insertion and consecutive with it
|
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119 in the buffer, combine the two. */
|
|
120 if (CONSP (b->undo_list))
|
|
121 {
|
|
122 Lisp_Object elt;
|
|
123 elt = XCAR (b->undo_list);
|
|
124 if (CONSP (elt)
|
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125 && INTP (XCAR (elt))
|
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126 && INTP (XCDR (elt))
|
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127 && XINT (XCDR (elt)) == beg)
|
|
128 {
|
|
129 XCDR (elt) = make_int (beg + length);
|
|
130 return;
|
|
131 }
|
|
132 }
|
|
133
|
|
134 b->undo_list = Fcons (Fcons (make_int (beg),
|
|
135 make_int (beg + length)),
|
|
136 b->undo_list);
|
|
137 }
|
|
138
|
|
139 /* Record that a deletion is about to take place,
|
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140 for LENGTH characters at location BEG. */
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|
141
|
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142 void
|
665
|
143 record_delete (struct buffer *b, Charbpos beg, Charcount length)
|
428
|
144 {
|
|
145 /* This function can GC */
|
|
146 Lisp_Object sbeg;
|
|
147 int at_boundary;
|
|
148
|
|
149 if (!undo_prelude (b, 1))
|
|
150 return;
|
|
151
|
|
152 at_boundary = (CONSP (b->undo_list)
|
|
153 && NILP (XCAR (b->undo_list)));
|
|
154
|
|
155 if (BUF_PT (b) == beg + length)
|
|
156 sbeg = make_int (-beg);
|
|
157 else
|
|
158 sbeg = make_int (beg);
|
|
159
|
|
160 /* If we are just after an undo boundary, and
|
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161 point wasn't at start of deleted range, record where it was. */
|
|
162 if (at_boundary
|
|
163 && BUFFERP (last_point_position_buffer)
|
|
164 && b == XBUFFER (last_point_position_buffer)
|
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165 && last_point_position != XINT (sbeg))
|
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166 b->undo_list = Fcons (make_int (last_point_position), b->undo_list);
|
|
167
|
|
168 b->undo_list = Fcons (Fcons (make_string_from_buffer (b, beg,
|
|
169 length),
|
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170 sbeg),
|
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171 b->undo_list);
|
|
172 }
|
|
173
|
|
174 /* Record that a replacement is about to take place,
|
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175 for LENGTH characters at location BEG.
|
|
176 The replacement does not change the number of characters. */
|
|
177
|
|
178 void
|
665
|
179 record_change (struct buffer *b, Charbpos beg, Charcount length)
|
428
|
180 {
|
|
181 record_delete (b, beg, length);
|
|
182 record_insert (b, beg, length);
|
|
183 }
|
|
184
|
|
185 /* Record that an EXTENT is about to be attached or detached in its buffer.
|
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186 This works much like a deletion or insertion, except that there's no string.
|
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187 The tricky part is that the buffer we operate on comes from EXTENT.
|
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188 Most extent changes happen as a side effect of string insertion and
|
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189 deletion; this call is solely for Fdetach_extent() and Finsert_extent().
|
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190 */
|
|
191 void
|
|
192 record_extent (Lisp_Object extent, int attached)
|
|
193 {
|
|
194 Lisp_Object obj = Fextent_object (extent);
|
|
195
|
|
196 if (BUFFERP (obj))
|
|
197 {
|
|
198 Lisp_Object token;
|
|
199 struct buffer *b = XBUFFER (obj);
|
|
200 if (!undo_prelude (b, 1))
|
|
201 return;
|
|
202 if (attached)
|
|
203 token = extent;
|
|
204 else
|
|
205 token = list3 (extent, Fextent_start_position (extent),
|
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206 Fextent_end_position (extent));
|
|
207 b->undo_list = Fcons (token, b->undo_list);
|
|
208 }
|
|
209 else
|
|
210 return;
|
|
211 }
|
|
212
|
|
213 #if 0 /* FSFmacs */
|
|
214 /* Record a change in property PROP (whose old value was VAL)
|
|
215 for LENGTH characters starting at position BEG in BUFFER. */
|
|
216
|
665
|
217 record_property_change (Charbpos beg, Charcount length,
|
428
|
218 Lisp_Object prop, Lisp_Object value,
|
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219 Lisp_Object buffer)
|
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220 {
|
|
221 Lisp_Object lbeg, lend, entry;
|
|
222 struct buffer *b = XBUFFER (buffer);
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223
|
|
224 if (!undo_prelude (b, 1))
|
|
225 return;
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|
226
|
|
227 lbeg = make_int (beg);
|
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228 lend = make_int (beg + length);
|
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229 entry = Fcons (Qnil, Fcons (prop, Fcons (value, Fcons (lbeg, lend))));
|
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230 b->undo_list = Fcons (entry, b->undo_list);
|
|
231 }
|
|
232 #endif /* FSFmacs */
|
|
233
|
|
234
|
|
235 DEFUN ("undo-boundary", Fundo_boundary, 0, 0, 0, /*
|
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236 Mark a boundary between units of undo.
|
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237 An undo command will stop at this point,
|
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238 but another undo command will undo to the previous boundary.
|
|
239 */
|
|
240 ())
|
|
241 {
|
|
242 if (EQ (current_buffer->undo_list, Qt))
|
|
243 return Qnil;
|
|
244 undo_boundary (current_buffer);
|
|
245 return Qnil;
|
|
246 }
|
|
247
|
|
248 /* At garbage collection time, make an undo list shorter at the end,
|
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249 returning the truncated list.
|
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250 MINSIZE and MAXSIZE are the limits on size allowed, as described below.
|
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251 In practice, these are the values of undo-threshold and
|
|
252 undo-high-threshold. */
|
|
253
|
|
254 Lisp_Object
|
|
255 truncate_undo_list (Lisp_Object list, int minsize, int maxsize)
|
|
256 {
|
|
257 Lisp_Object prev, next, last_boundary;
|
|
258 int size_so_far = 0;
|
|
259
|
|
260 if (!(minsize > 0 || maxsize > 0))
|
|
261 return list;
|
|
262
|
|
263 prev = Qnil;
|
|
264 next = list;
|
|
265 last_boundary = Qnil;
|
|
266
|
|
267 if (!CONSP (list))
|
|
268 return (list);
|
|
269
|
|
270 /* Always preserve at least the most recent undo record.
|
|
271 If the first element is an undo boundary, skip past it. */
|
|
272 if (CONSP (next)
|
|
273 && NILP (XCAR (next)))
|
|
274 {
|
|
275 /* Add in the space occupied by this element and its chain link. */
|
440
|
276 size_so_far += sizeof (Lisp_Cons);
|
428
|
277
|
|
278 /* Advance to next element. */
|
|
279 prev = next;
|
|
280 next = XCDR (next);
|
|
281 }
|
|
282 while (CONSP (next)
|
|
283 && !NILP (XCAR (next)))
|
|
284 {
|
|
285 Lisp_Object elt;
|
|
286 elt = XCAR (next);
|
|
287
|
|
288 /* Add in the space occupied by this element and its chain link. */
|
440
|
289 size_so_far += sizeof (Lisp_Cons);
|
428
|
290 if (CONSP (elt))
|
|
291 {
|
440
|
292 size_so_far += sizeof (Lisp_Cons);
|
428
|
293 if (STRINGP (XCAR (elt)))
|
440
|
294 size_so_far += (sizeof (Lisp_String) - 1
|
428
|
295 + XSTRING_LENGTH (XCAR (elt)));
|
|
296 }
|
|
297
|
|
298 /* Advance to next element. */
|
|
299 prev = next;
|
|
300 next = XCDR (next);
|
|
301 }
|
|
302 if (CONSP (next))
|
|
303 last_boundary = prev;
|
|
304
|
|
305 while (CONSP (next))
|
|
306 {
|
|
307 Lisp_Object elt;
|
|
308 elt = XCAR (next);
|
|
309
|
|
310 /* When we get to a boundary, decide whether to truncate
|
|
311 either before or after it. The lower threshold, MINSIZE,
|
|
312 tells us to truncate after it. If its size pushes past
|
|
313 the higher threshold MAXSIZE as well, we truncate before it. */
|
|
314 if (NILP (elt))
|
|
315 {
|
|
316 if (size_so_far > maxsize && maxsize > 0)
|
|
317 break;
|
|
318 last_boundary = prev;
|
|
319 if (size_so_far > minsize && minsize > 0)
|
|
320 break;
|
|
321 }
|
|
322
|
|
323 /* Add in the space occupied by this element and its chain link. */
|
440
|
324 size_so_far += sizeof (Lisp_Cons);
|
428
|
325 if (CONSP (elt))
|
|
326 {
|
440
|
327 size_so_far += sizeof (Lisp_Cons);
|
428
|
328 if (STRINGP (XCAR (elt)))
|
440
|
329 size_so_far += (sizeof (Lisp_String) - 1
|
428
|
330 + XSTRING_LENGTH (XCAR (elt)));
|
|
331 }
|
|
332
|
|
333 /* Advance to next element. */
|
|
334 prev = next;
|
|
335 next = XCDR (next);
|
|
336 }
|
|
337
|
|
338 /* If we scanned the whole list, it is short enough; don't change it. */
|
|
339 if (NILP (next))
|
|
340 return list;
|
|
341
|
|
342 /* Truncate at the boundary where we decided to truncate. */
|
|
343 if (!NILP (last_boundary))
|
|
344 {
|
|
345 XCDR (last_boundary) = Qnil;
|
|
346 return list;
|
|
347 }
|
|
348 else
|
|
349 return Qnil;
|
|
350 }
|
|
351
|
|
352 DEFUN ("primitive-undo", Fprimitive_undo, 2, 2, 0, /*
|
|
353 Undo COUNT records from the front of the list LIST.
|
|
354 Return what remains of the list.
|
|
355 */
|
|
356 (count, list))
|
|
357 {
|
|
358 struct gcpro gcpro1, gcpro2;
|
|
359 Lisp_Object next = Qnil;
|
|
360 /* This function can GC */
|
|
361 int arg;
|
853
|
362 int speccount = internal_bind_int (&inside_undo, 1);
|
428
|
363
|
|
364 #if 0 /* This is a good feature, but would make undo-start
|
|
365 unable to do what is expected. */
|
|
366 Lisp_Object tem;
|
|
367
|
|
368 /* If the head of the list is a boundary, it is the boundary
|
|
369 preceding this command. Get rid of it and don't count it. */
|
|
370 tem = Fcar (list);
|
|
371 if (NILP (tem))
|
|
372 list = Fcdr (list);
|
|
373 #endif
|
|
374
|
|
375 CHECK_INT (count);
|
|
376 arg = XINT (count);
|
|
377 next = Qnil;
|
|
378 GCPRO2 (next, list);
|
|
379
|
|
380 /* Don't let read-only properties interfere with undo. */
|
|
381 if (NILP (current_buffer->read_only))
|
|
382 specbind (Qinhibit_read_only, Qt);
|
|
383
|
|
384 while (arg > 0)
|
|
385 {
|
|
386 while (1)
|
|
387 {
|
|
388 if (NILP (list))
|
|
389 break;
|
|
390 else if (!CONSP (list))
|
|
391 goto rotten;
|
|
392 next = XCAR (list);
|
|
393 list = XCDR (list);
|
|
394 /* Exit inner loop at undo boundary. */
|
|
395 if (NILP (next))
|
|
396 break;
|
|
397 /* Handle an integer by setting point to that value. */
|
|
398 else if (INTP (next))
|
|
399 BUF_SET_PT (current_buffer,
|
665
|
400 charbpos_clip_to_bounds (BUF_BEGV (current_buffer),
|
428
|
401 XINT (next),
|
|
402 BUF_ZV (current_buffer)));
|
|
403 else if (CONSP (next))
|
|
404 {
|
|
405 Lisp_Object car = XCAR (next);
|
|
406 Lisp_Object cdr = XCDR (next);
|
|
407
|
|
408 if (EQ (car, Qt))
|
|
409 {
|
|
410 /* Element (t high . low) records previous modtime. */
|
|
411 Lisp_Object high, low;
|
|
412 int mod_time;
|
|
413 if (!CONSP (cdr)) goto rotten;
|
|
414 high = XCAR (cdr);
|
|
415 low = XCDR (cdr);
|
|
416 if (!INTP (high) || !INTP (low)) goto rotten;
|
|
417 mod_time = (XINT (high) << 16) + XINT (low);
|
|
418 /* If this records an obsolete save
|
|
419 (not matching the actual disk file)
|
|
420 then don't mark unmodified. */
|
|
421 if (mod_time != current_buffer->modtime)
|
|
422 break;
|
|
423 #ifdef CLASH_DETECTION
|
|
424 Funlock_buffer ();
|
|
425 #endif /* CLASH_DETECTION */
|
2297
|
426 /* #### need to check if this can GC */
|
428
|
427 Fset_buffer_modified_p (Qnil, Qnil);
|
|
428 }
|
|
429 else if (EXTENTP (car))
|
|
430 {
|
|
431 /* Element (extent start end) means that EXTENT was
|
|
432 detached, and we need to reattach it. */
|
|
433 Lisp_Object extent_obj, start, end;
|
|
434
|
|
435 extent_obj = car;
|
|
436 start = Fcar (cdr);
|
|
437 end = Fcar (Fcdr (cdr));
|
|
438
|
|
439 if (!INTP (start) || !INTP (end))
|
|
440 goto rotten;
|
|
441 Fset_extent_endpoints (extent_obj, start, end,
|
|
442 Fcurrent_buffer ());
|
|
443 }
|
|
444 #if 0 /* FSFmacs */
|
|
445 else if (EQ (car, Qnil))
|
|
446 {
|
|
447 /* Element (nil prop val beg . end) is property change. */
|
|
448 Lisp_Object beg, end, prop, val;
|
|
449
|
|
450 prop = Fcar (cdr);
|
|
451 cdr = Fcdr (cdr);
|
|
452 val = Fcar (cdr);
|
|
453 cdr = Fcdr (cdr);
|
|
454 beg = Fcar (cdr);
|
|
455 end = Fcdr (cdr);
|
|
456
|
|
457 Fput_text_property (beg, end, prop, val, Qnil);
|
|
458 }
|
|
459 #endif /* FSFmacs */
|
|
460 else if (INTP (car) && INTP (cdr))
|
|
461 {
|
|
462 /* Element (BEG . END) means range was inserted. */
|
|
463
|
|
464 if (XINT (car) < BUF_BEGV (current_buffer)
|
|
465 || XINT (cdr) > BUF_ZV (current_buffer))
|
563
|
466 signal_error (Qinvalid_operation, "Changes to be undone are outside visible portion of buffer", Qunbound);
|
428
|
467 /* Set point first thing, so that undoing this undo
|
|
468 does not send point back to where it is now. */
|
|
469 Fgoto_char (car, Qnil);
|
|
470 Fdelete_region (car, cdr, Qnil);
|
|
471 }
|
|
472 else if (STRINGP (car) && INTP (cdr))
|
|
473 {
|
|
474 /* Element (STRING . POS) means STRING was deleted. */
|
|
475 Lisp_Object membuf = car;
|
|
476 int pos = XINT (cdr);
|
|
477
|
|
478 if (pos < 0)
|
|
479 {
|
|
480 if (-pos < BUF_BEGV (current_buffer) || -pos > BUF_ZV (current_buffer))
|
563
|
481 signal_error (Qinvalid_operation, "Changes to be undone are outside visible portion of buffer", Qunbound);
|
428
|
482 BUF_SET_PT (current_buffer, -pos);
|
|
483 Finsert (1, &membuf);
|
|
484 }
|
|
485 else
|
|
486 {
|
|
487 if (pos < BUF_BEGV (current_buffer) || pos > BUF_ZV (current_buffer))
|
563
|
488 signal_error (Qinvalid_operation, "Changes to be undone are outside visible portion of buffer", Qunbound);
|
428
|
489 BUF_SET_PT (current_buffer, pos);
|
|
490
|
|
491 /* Insert before markers so that if the mark is
|
|
492 currently on the boundary of this deletion, it
|
|
493 ends up on the other side of the now-undeleted
|
|
494 text from point. Since undo doesn't even keep
|
|
495 track of the mark, this isn't really necessary,
|
|
496 but it may lead to better behavior in certain
|
|
497 situations.
|
|
498
|
|
499 I'm doubtful that this is safe; you could mess
|
|
500 up the process-output mark in shell buffers, so
|
|
501 until I hear a compelling reason for this change,
|
|
502 I'm leaving it out. -jwz
|
|
503 */
|
|
504 /* Finsert_before_markers (1, &membuf); */
|
|
505 Finsert (1, &membuf);
|
|
506 BUF_SET_PT (current_buffer, pos);
|
|
507 }
|
|
508 }
|
|
509 else
|
|
510 {
|
|
511 goto rotten;
|
|
512 }
|
|
513 }
|
|
514 else if (EXTENTP (next))
|
|
515 Fdetach_extent (next);
|
|
516 else
|
|
517 {
|
|
518 rotten:
|
563
|
519 signal_continuable_error
|
|
520 (Qinvalid_state,
|
|
521 "Something rotten in the state of undo", next);
|
428
|
522 }
|
|
523 }
|
|
524 arg--;
|
|
525 }
|
|
526
|
|
527 UNGCPRO;
|
771
|
528 return unbind_to_1 (speccount, list);
|
428
|
529 }
|
|
530
|
|
531 void
|
|
532 syms_of_undo (void)
|
|
533 {
|
|
534 DEFSUBR (Fprimitive_undo);
|
|
535 DEFSUBR (Fundo_boundary);
|
563
|
536 DEFSYMBOL (Qinhibit_read_only);
|
428
|
537 }
|
|
538
|
|
539 void
|
|
540 reinit_vars_of_undo (void)
|
|
541 {
|
|
542 inside_undo = 0;
|
|
543 }
|
|
544
|
|
545 void
|
|
546 vars_of_undo (void)
|
|
547 {
|
|
548 pending_boundary = Qnil;
|
|
549 staticpro (&pending_boundary);
|
|
550 last_undo_buffer = Qnil;
|
|
551 staticpro (&last_undo_buffer);
|
|
552 }
|