| 1 | /* undo.c - manage list of changes to lines, offering opportunity to undo them */ |
| 2 | |
| 3 | /* Copyright (C) 1987-2017 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of the GNU Readline Library (Readline), a library |
| 6 | for reading lines of text with interactive input and history editing. |
| 7 | |
| 8 | Readline is free software: you can redistribute it and/or modify |
| 9 | it under the terms of the GNU General Public License as published by |
| 10 | the Free Software Foundation, either version 3 of the License, or |
| 11 | (at your option) any later version. |
| 12 | |
| 13 | Readline is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with Readline. If not, see <http://www.gnu.org/licenses/>. |
| 20 | */ |
| 21 | |
| 22 | #define READLINE_LIBRARY |
| 23 | |
| 24 | #if defined (HAVE_CONFIG_H) |
| 25 | # include <config.h> |
| 26 | #endif |
| 27 | |
| 28 | #include <sys/types.h> |
| 29 | |
| 30 | #if defined (HAVE_UNISTD_H) |
| 31 | # include <unistd.h> /* for _POSIX_VERSION */ |
| 32 | #endif /* HAVE_UNISTD_H */ |
| 33 | |
| 34 | #if defined (HAVE_STDLIB_H) |
| 35 | # include <stdlib.h> |
| 36 | #else |
| 37 | # include "ansi_stdlib.h" |
| 38 | #endif /* HAVE_STDLIB_H */ |
| 39 | |
| 40 | #include <stdio.h> |
| 41 | |
| 42 | /* System-specific feature definitions and include files. */ |
| 43 | #include "rldefs.h" |
| 44 | |
| 45 | /* Some standard library routines. */ |
| 46 | #include "readline.h" |
| 47 | #include "history.h" |
| 48 | |
| 49 | #include "rlprivate.h" |
| 50 | #include "xmalloc.h" |
| 51 | |
| 52 | extern void _hs_replace_history_data PARAMS((int, histdata_t *, histdata_t *)); |
| 53 | |
| 54 | extern HIST_ENTRY *_rl_saved_line_for_history; |
| 55 | |
| 56 | /* Non-zero tells rl_delete_text and rl_insert_text to not add to |
| 57 | the undo list. */ |
| 58 | int _rl_doing_an_undo = 0; |
| 59 | |
| 60 | /* How many unclosed undo groups we currently have. */ |
| 61 | int _rl_undo_group_level = 0; |
| 62 | |
| 63 | /* The current undo list for THE_LINE. */ |
| 64 | UNDO_LIST *rl_undo_list = (UNDO_LIST *)NULL; |
| 65 | |
| 66 | /* **************************************************************** */ |
| 67 | /* */ |
| 68 | /* Undo, and Undoing */ |
| 69 | /* */ |
| 70 | /* **************************************************************** */ |
| 71 | |
| 72 | static UNDO_LIST * |
| 73 | alloc_undo_entry (enum undo_code what, int start, int end, char *text) |
| 74 | { |
| 75 | UNDO_LIST *temp; |
| 76 | |
| 77 | temp = (UNDO_LIST *)xmalloc (sizeof (UNDO_LIST)); |
| 78 | temp->what = what; |
| 79 | temp->start = start; |
| 80 | temp->end = end; |
| 81 | temp->text = text; |
| 82 | |
| 83 | temp->next = (UNDO_LIST *)NULL; |
| 84 | return temp; |
| 85 | } |
| 86 | |
| 87 | /* Remember how to undo something. Concatenate some undos if that |
| 88 | seems right. */ |
| 89 | void |
| 90 | rl_add_undo (enum undo_code what, int start, int end, char *text) |
| 91 | { |
| 92 | UNDO_LIST *temp; |
| 93 | |
| 94 | temp = alloc_undo_entry (what, start, end, text); |
| 95 | temp->next = rl_undo_list; |
| 96 | rl_undo_list = temp; |
| 97 | } |
| 98 | |
| 99 | /* Free an UNDO_LIST */ |
| 100 | void |
| 101 | _rl_free_undo_list (UNDO_LIST *ul) |
| 102 | { |
| 103 | UNDO_LIST *release; |
| 104 | |
| 105 | while (ul) |
| 106 | { |
| 107 | release = ul; |
| 108 | ul = ul->next; |
| 109 | |
| 110 | if (release->what == UNDO_DELETE) |
| 111 | xfree (release->text); |
| 112 | |
| 113 | xfree (release); |
| 114 | } |
| 115 | } |
| 116 | |
| 117 | /* Free the existing undo list. */ |
| 118 | void |
| 119 | rl_free_undo_list (void) |
| 120 | { |
| 121 | UNDO_LIST *release, *orig_list; |
| 122 | |
| 123 | orig_list = rl_undo_list; |
| 124 | _rl_free_undo_list (rl_undo_list); |
| 125 | rl_undo_list = (UNDO_LIST *)NULL; |
| 126 | _hs_replace_history_data (-1, (histdata_t *)orig_list, (histdata_t *)NULL); |
| 127 | } |
| 128 | |
| 129 | UNDO_LIST * |
| 130 | _rl_copy_undo_entry (UNDO_LIST *entry) |
| 131 | { |
| 132 | UNDO_LIST *new; |
| 133 | |
| 134 | new = alloc_undo_entry (entry->what, entry->start, entry->end, (char *)NULL); |
| 135 | new->text = entry->text ? savestring (entry->text) : 0; |
| 136 | return new; |
| 137 | } |
| 138 | |
| 139 | UNDO_LIST * |
| 140 | _rl_copy_undo_list (UNDO_LIST *head) |
| 141 | { |
| 142 | UNDO_LIST *list, *new, *roving, *c; |
| 143 | |
| 144 | if (head == 0) |
| 145 | return head; |
| 146 | |
| 147 | list = head; |
| 148 | new = 0; |
| 149 | while (list) |
| 150 | { |
| 151 | c = _rl_copy_undo_entry (list); |
| 152 | if (new == 0) |
| 153 | roving = new = c; |
| 154 | else |
| 155 | { |
| 156 | roving->next = c; |
| 157 | roving = roving->next; |
| 158 | } |
| 159 | list = list->next; |
| 160 | } |
| 161 | |
| 162 | roving->next = 0; |
| 163 | return new; |
| 164 | } |
| 165 | |
| 166 | /* Undo the next thing in the list. Return 0 if there |
| 167 | is nothing to undo, or non-zero if there was. */ |
| 168 | int |
| 169 | rl_do_undo (void) |
| 170 | { |
| 171 | UNDO_LIST *release, *search; |
| 172 | int waiting_for_begin, start, end; |
| 173 | HIST_ENTRY *cur, *temp; |
| 174 | |
| 175 | #define TRANS(i) ((i) == -1 ? rl_point : ((i) == -2 ? rl_end : (i))) |
| 176 | |
| 177 | start = end = waiting_for_begin = 0; |
| 178 | do |
| 179 | { |
| 180 | if (rl_undo_list == 0) |
| 181 | return (0); |
| 182 | |
| 183 | _rl_doing_an_undo = 1; |
| 184 | RL_SETSTATE(RL_STATE_UNDOING); |
| 185 | |
| 186 | /* To better support vi-mode, a start or end value of -1 means |
| 187 | rl_point, and a value of -2 means rl_end. */ |
| 188 | if (rl_undo_list->what == UNDO_DELETE || rl_undo_list->what == UNDO_INSERT) |
| 189 | { |
| 190 | start = TRANS (rl_undo_list->start); |
| 191 | end = TRANS (rl_undo_list->end); |
| 192 | } |
| 193 | |
| 194 | switch (rl_undo_list->what) |
| 195 | { |
| 196 | /* Undoing deletes means inserting some text. */ |
| 197 | case UNDO_DELETE: |
| 198 | rl_point = start; |
| 199 | rl_insert_text (rl_undo_list->text); |
| 200 | xfree (rl_undo_list->text); |
| 201 | break; |
| 202 | |
| 203 | /* Undoing inserts means deleting some text. */ |
| 204 | case UNDO_INSERT: |
| 205 | rl_delete_text (start, end); |
| 206 | rl_point = start; |
| 207 | break; |
| 208 | |
| 209 | /* Undoing an END means undoing everything 'til we get to a BEGIN. */ |
| 210 | case UNDO_END: |
| 211 | waiting_for_begin++; |
| 212 | break; |
| 213 | |
| 214 | /* Undoing a BEGIN means that we are done with this group. */ |
| 215 | case UNDO_BEGIN: |
| 216 | if (waiting_for_begin) |
| 217 | waiting_for_begin--; |
| 218 | else |
| 219 | rl_ding (); |
| 220 | break; |
| 221 | } |
| 222 | |
| 223 | _rl_doing_an_undo = 0; |
| 224 | RL_UNSETSTATE(RL_STATE_UNDOING); |
| 225 | |
| 226 | release = rl_undo_list; |
| 227 | rl_undo_list = rl_undo_list->next; |
| 228 | release->next = 0; /* XXX */ |
| 229 | |
| 230 | /* If we are editing a history entry, make sure the change is replicated |
| 231 | in the history entry's line */ |
| 232 | cur = current_history (); |
| 233 | if (cur && cur->data && (UNDO_LIST *)cur->data == release) |
| 234 | { |
| 235 | temp = replace_history_entry (where_history (), rl_line_buffer, (histdata_t)rl_undo_list); |
| 236 | xfree (temp->line); |
| 237 | FREE (temp->timestamp); |
| 238 | xfree (temp); |
| 239 | } |
| 240 | |
| 241 | /* Make sure there aren't any history entries with that undo list */ |
| 242 | _hs_replace_history_data (-1, (histdata_t *)release, (histdata_t *)rl_undo_list); |
| 243 | |
| 244 | /* And make sure this list isn't anywhere in the saved line for history */ |
| 245 | if (_rl_saved_line_for_history && _rl_saved_line_for_history->data) |
| 246 | { |
| 247 | /* Brute force; no finesse here */ |
| 248 | search = (UNDO_LIST *)_rl_saved_line_for_history->data; |
| 249 | if (search == release) |
| 250 | _rl_saved_line_for_history->data = rl_undo_list; |
| 251 | else |
| 252 | { |
| 253 | while (search->next) |
| 254 | { |
| 255 | if (search->next == release) |
| 256 | { |
| 257 | search->next = rl_undo_list; |
| 258 | break; |
| 259 | } |
| 260 | search = search->next; |
| 261 | } |
| 262 | } |
| 263 | } |
| 264 | |
| 265 | xfree (release); |
| 266 | } |
| 267 | while (waiting_for_begin); |
| 268 | |
| 269 | return (1); |
| 270 | } |
| 271 | #undef TRANS |
| 272 | |
| 273 | int |
| 274 | _rl_fix_last_undo_of_type (int type, int start, int end) |
| 275 | { |
| 276 | UNDO_LIST *rl; |
| 277 | |
| 278 | for (rl = rl_undo_list; rl; rl = rl->next) |
| 279 | { |
| 280 | if (rl->what == type) |
| 281 | { |
| 282 | rl->start = start; |
| 283 | rl->end = end; |
| 284 | return 0; |
| 285 | } |
| 286 | } |
| 287 | return 1; |
| 288 | } |
| 289 | |
| 290 | /* Begin a group. Subsequent undos are undone as an atomic operation. */ |
| 291 | int |
| 292 | rl_begin_undo_group (void) |
| 293 | { |
| 294 | rl_add_undo (UNDO_BEGIN, 0, 0, 0); |
| 295 | _rl_undo_group_level++; |
| 296 | return 0; |
| 297 | } |
| 298 | |
| 299 | /* End an undo group started with rl_begin_undo_group (). */ |
| 300 | int |
| 301 | rl_end_undo_group (void) |
| 302 | { |
| 303 | rl_add_undo (UNDO_END, 0, 0, 0); |
| 304 | _rl_undo_group_level--; |
| 305 | return 0; |
| 306 | } |
| 307 | |
| 308 | /* Save an undo entry for the text from START to END. */ |
| 309 | int |
| 310 | rl_modifying (int start, int end) |
| 311 | { |
| 312 | if (start > end) |
| 313 | { |
| 314 | SWAP (start, end); |
| 315 | } |
| 316 | |
| 317 | if (start != end) |
| 318 | { |
| 319 | char *temp = rl_copy_text (start, end); |
| 320 | rl_begin_undo_group (); |
| 321 | rl_add_undo (UNDO_DELETE, start, end, temp); |
| 322 | rl_add_undo (UNDO_INSERT, start, end, (char *)NULL); |
| 323 | rl_end_undo_group (); |
| 324 | } |
| 325 | return 0; |
| 326 | } |
| 327 | |
| 328 | /* Revert the current line to its previous state. */ |
| 329 | int |
| 330 | rl_revert_line (int count, int key) |
| 331 | { |
| 332 | if (rl_undo_list == 0) |
| 333 | rl_ding (); |
| 334 | else |
| 335 | { |
| 336 | while (rl_undo_list) |
| 337 | rl_do_undo (); |
| 338 | #if defined (VI_MODE) |
| 339 | if (rl_editing_mode == vi_mode) |
| 340 | rl_point = rl_mark = 0; /* rl_end should be set correctly */ |
| 341 | #endif |
| 342 | } |
| 343 | |
| 344 | return 0; |
| 345 | } |
| 346 | |
| 347 | /* Do some undoing of things that were done. */ |
| 348 | int |
| 349 | rl_undo_command (int count, int key) |
| 350 | { |
| 351 | if (count < 0) |
| 352 | return 0; /* Nothing to do. */ |
| 353 | |
| 354 | while (count) |
| 355 | { |
| 356 | if (rl_do_undo ()) |
| 357 | count--; |
| 358 | else |
| 359 | { |
| 360 | rl_ding (); |
| 361 | break; |
| 362 | } |
| 363 | } |
| 364 | return 0; |
| 365 | } |