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[gdb.git] / readline / undo.c
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1 /* readline.c -- a general facility for reading lines of input
2 with emacs style editing and completion. */
4 /* Copyright (C) 1987, 1989, 1992 Free Software Foundation, Inc.
6 This file is part of the GNU Readline Library, a library for
7 reading lines of text with interactive input and history editing.
9 The GNU Readline Library is free software; you can redistribute it
10 and/or modify it under the terms of the GNU General Public License
11 as published by the Free Software Foundation; either version 2, or
12 (at your option) any later version.
14 The GNU Readline Library is distributed in the hope that it will be
15 useful, but WITHOUT ANY WARRANTY; without even the implied warranty
16 of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 The GNU General Public License is often shipped with GNU software, and
20 is generally kept in a file called COPYING or LICENSE. If you do not
21 have a copy of the license, write to the Free Software Foundation,
22 59 Temple Place, Suite 330, Boston, MA 02111 USA. */
23 #define READLINE_LIBRARY
25 #if defined (HAVE_CONFIG_H)
26 # include <config.h>
27 #endif
29 #include <sys/types.h>
31 #if defined (HAVE_UNISTD_H)
32 # include <unistd.h> /* for _POSIX_VERSION */
33 #endif /* HAVE_UNISTD_H */
35 #if defined (HAVE_STDLIB_H)
36 # include <stdlib.h>
37 #else
38 # include "ansi_stdlib.h"
39 #endif /* HAVE_STDLIB_H */
41 #include <stdio.h>
43 /* System-specific feature definitions and include files. */
44 #include "rldefs.h"
46 /* Some standard library routines. */
47 #include "readline.h"
48 #include "history.h"
50 #include "rlprivate.h"
51 #include "xmalloc.h"
53 /* Non-zero tells rl_delete_text and rl_insert_text to not add to
54 the undo list. */
55 int _rl_doing_an_undo = 0;
57 /* How many unclosed undo groups we currently have. */
58 int _rl_undo_group_level = 0;
60 /* The current undo list for THE_LINE. */
61 UNDO_LIST *rl_undo_list = (UNDO_LIST *)NULL;
63 /* **************************************************************** */
64 /* */
65 /* Undo, and Undoing */
66 /* */
67 /* **************************************************************** */
69 /* Remember how to undo something. Concatenate some undos if that
70 seems right. */
71 void
72 rl_add_undo (what, start, end, text)
73 enum undo_code what;
74 int start, end;
75 char *text;
77 UNDO_LIST *temp = (UNDO_LIST *)xmalloc (sizeof (UNDO_LIST));
78 temp->what = what;
79 temp->start = start;
80 temp->end = end;
81 temp->text = text;
82 temp->next = rl_undo_list;
83 rl_undo_list = temp;
86 /* Free the existing undo list. */
87 void
88 rl_free_undo_list ()
90 while (rl_undo_list)
92 UNDO_LIST *release = rl_undo_list;
93 rl_undo_list = rl_undo_list->next;
95 if (release->what == UNDO_DELETE)
96 free (release->text);
98 free (release);
100 rl_undo_list = (UNDO_LIST *)NULL;
103 /* Undo the next thing in the list. Return 0 if there
104 is nothing to undo, or non-zero if there was. */
106 rl_do_undo ()
108 UNDO_LIST *release;
109 int waiting_for_begin, start, end;
111 #define TRANS(i) ((i) == -1 ? rl_point : ((i) == -2 ? rl_end : (i)))
113 start = end = waiting_for_begin = 0;
116 if (!rl_undo_list)
117 return (0);
119 _rl_doing_an_undo = 1;
120 RL_SETSTATE(RL_STATE_UNDOING);
122 /* To better support vi-mode, a start or end value of -1 means
123 rl_point, and a value of -2 means rl_end. */
124 if (rl_undo_list->what == UNDO_DELETE || rl_undo_list->what == UNDO_INSERT)
126 start = TRANS (rl_undo_list->start);
127 end = TRANS (rl_undo_list->end);
130 switch (rl_undo_list->what)
132 /* Undoing deletes means inserting some text. */
133 case UNDO_DELETE:
134 rl_point = start;
135 rl_insert_text (rl_undo_list->text);
136 free (rl_undo_list->text);
137 break;
139 /* Undoing inserts means deleting some text. */
140 case UNDO_INSERT:
141 rl_delete_text (start, end);
142 rl_point = start;
143 break;
145 /* Undoing an END means undoing everything 'til we get to a BEGIN. */
146 case UNDO_END:
147 waiting_for_begin++;
148 break;
150 /* Undoing a BEGIN means that we are done with this group. */
151 case UNDO_BEGIN:
152 if (waiting_for_begin)
153 waiting_for_begin--;
154 else
155 rl_ding ();
156 break;
159 _rl_doing_an_undo = 0;
160 RL_UNSETSTATE(RL_STATE_UNDOING);
162 release = rl_undo_list;
163 rl_undo_list = rl_undo_list->next;
164 free (release);
166 while (waiting_for_begin);
168 return (1);
170 #undef TRANS
173 _rl_fix_last_undo_of_type (type, start, end)
174 int type, start, end;
176 UNDO_LIST *rl;
178 for (rl = rl_undo_list; rl; rl = rl->next)
180 if (rl->what == type)
182 rl->start = start;
183 rl->end = end;
184 return 0;
187 return 1;
190 /* Begin a group. Subsequent undos are undone as an atomic operation. */
192 rl_begin_undo_group ()
194 rl_add_undo (UNDO_BEGIN, 0, 0, 0);
195 _rl_undo_group_level++;
196 return 0;
199 /* End an undo group started with rl_begin_undo_group (). */
201 rl_end_undo_group ()
203 rl_add_undo (UNDO_END, 0, 0, 0);
204 _rl_undo_group_level--;
205 return 0;
208 /* Save an undo entry for the text from START to END. */
210 rl_modifying (start, end)
211 int start, end;
213 if (start > end)
215 SWAP (start, end);
218 if (start != end)
220 char *temp = rl_copy_text (start, end);
221 rl_begin_undo_group ();
222 rl_add_undo (UNDO_DELETE, start, end, temp);
223 rl_add_undo (UNDO_INSERT, start, end, (char *)NULL);
224 rl_end_undo_group ();
226 return 0;
229 /* Revert the current line to its previous state. */
231 rl_revert_line (count, key)
232 int count, key;
234 if (!rl_undo_list)
235 rl_ding ();
236 else
238 while (rl_undo_list)
239 rl_do_undo ();
240 #if defined (VI_MODE)
241 if (rl_editing_mode == vi_mode)
242 rl_point = rl_mark = 0; /* rl_end should be set correctly */
243 #endif
246 return 0;
249 /* Do some undoing of things that were done. */
251 rl_undo_command (count, key)
252 int count, key;
254 if (count < 0)
255 return 0; /* Nothing to do. */
257 while (count)
259 if (rl_do_undo ())
260 count--;
261 else
263 rl_ding ();
264 break;
267 return 0;