undo.c revision 21308
1/* readline.c -- a general facility for reading lines of input 2 with emacs style editing and completion. */ 3 4/* Copyright (C) 1987, 1989, 1992 Free Software Foundation, Inc. 5 6 This file is part of the GNU Readline Library, a library for 7 reading lines of text with interactive input and history editing. 8 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 1, or 12 (at your option) any later version. 13 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. 18 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, 22 675 Mass Ave, Cambridge, MA 02139, USA. */ 23#define READLINE_LIBRARY 24 25#if defined (HAVE_CONFIG_H) 26# include <config.h> 27#endif 28 29#include <sys/types.h> 30 31#if defined (HAVE_UNISTD_H) 32# include <unistd.h> /* for _POSIX_VERSION */ 33#endif /* HAVE_UNISTD_H */ 34 35#if defined (HAVE_STDLIB_H) 36# include <stdlib.h> 37#else 38# include "ansi_stdlib.h" 39#endif /* HAVE_STDLIB_H */ 40 41#include <setjmp.h> 42#include <stdio.h> 43 44/* System-specific feature definitions and include files. */ 45#include "rldefs.h" 46 47/* Some standard library routines. */ 48#include "readline.h" 49#include "history.h" 50 51#define SWAP(s, e) do { int t; t = s; s = e; e = t; } while (0) 52 53/* Non-zero tells rl_delete_text and rl_insert_text to not add to 54 the undo list. */ 55int _rl_doing_an_undo = 0; 56 57/* How many unclosed undo groups we currently have. */ 58int _rl_undo_group_level = 0; 59 60/* The current undo list for THE_LINE. */ 61UNDO_LIST *rl_undo_list = (UNDO_LIST *)NULL; 62 63/* **************************************************************** */ 64/* */ 65/* Undo, and Undoing */ 66/* */ 67/* **************************************************************** */ 68 69/* Remember how to undo something. Concatenate some undos if that 70 seems right. */ 71void 72rl_add_undo (what, start, end, text) 73 enum undo_code what; 74 int start, end; 75 char *text; 76{ 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; 84} 85 86/* Free the existing undo list. */ 87void 88free_undo_list () 89{ 90 while (rl_undo_list) 91 { 92 UNDO_LIST *release = rl_undo_list; 93 rl_undo_list = rl_undo_list->next; 94 95 if (release->what == UNDO_DELETE) 96 free (release->text); 97 98 free (release); 99 } 100 rl_undo_list = (UNDO_LIST *)NULL; 101} 102 103/* Undo the next thing in the list. Return 0 if there 104 is nothing to undo, or non-zero if there was. */ 105int 106rl_do_undo () 107{ 108 UNDO_LIST *release; 109 int waiting_for_begin = 0; 110 int start, end; 111 112#define TRANS(i) ((i) == -1 ? rl_point : ((i) == -2 ? rl_end : (i))) 113 114 do 115 { 116 if (!rl_undo_list) 117 return (0); 118 119 _rl_doing_an_undo = 1; 120 121 /* To better support vi-mode, a start or end value of -1 means 122 rl_point, and a value of -2 means rl_end. */ 123 if (rl_undo_list->what == UNDO_DELETE || rl_undo_list->what == UNDO_INSERT) 124 { 125 start = TRANS (rl_undo_list->start); 126 end = TRANS (rl_undo_list->end); 127 } 128 129 switch (rl_undo_list->what) 130 { 131 /* Undoing deletes means inserting some text. */ 132 case UNDO_DELETE: 133 rl_point = start; 134 rl_insert_text (rl_undo_list->text); 135 free (rl_undo_list->text); 136 break; 137 138 /* Undoing inserts means deleting some text. */ 139 case UNDO_INSERT: 140 rl_delete_text (start, end); 141 rl_point = start; 142 break; 143 144 /* Undoing an END means undoing everything 'til we get to a BEGIN. */ 145 case UNDO_END: 146 waiting_for_begin++; 147 break; 148 149 /* Undoing a BEGIN means that we are done with this group. */ 150 case UNDO_BEGIN: 151 if (waiting_for_begin) 152 waiting_for_begin--; 153 else 154 ding (); 155 break; 156 } 157 158 _rl_doing_an_undo = 0; 159 160 release = rl_undo_list; 161 rl_undo_list = rl_undo_list->next; 162 free (release); 163 } 164 while (waiting_for_begin); 165 166 return (1); 167} 168#undef TRANS 169 170int 171_rl_fix_last_undo_of_type (type, start, end) 172 int type, start, end; 173{ 174 UNDO_LIST *rl; 175 176 for (rl = rl_undo_list; rl; rl = rl->next) 177 { 178 if (rl->what == type) 179 { 180 rl->start = start; 181 rl->end = end; 182 return 0; 183 } 184 } 185 return 1; 186} 187 188/* Begin a group. Subsequent undos are undone as an atomic operation. */ 189int 190rl_begin_undo_group () 191{ 192 rl_add_undo (UNDO_BEGIN, 0, 0, 0); 193 _rl_undo_group_level++; 194 return 0; 195} 196 197/* End an undo group started with rl_begin_undo_group (). */ 198int 199rl_end_undo_group () 200{ 201 rl_add_undo (UNDO_END, 0, 0, 0); 202 _rl_undo_group_level--; 203 return 0; 204} 205 206/* Save an undo entry for the text from START to END. */ 207int 208rl_modifying (start, end) 209 int start, end; 210{ 211 if (start > end) 212 { 213 SWAP (start, end); 214 } 215 216 if (start != end) 217 { 218 char *temp = rl_copy_text (start, end); 219 rl_begin_undo_group (); 220 rl_add_undo (UNDO_DELETE, start, end, temp); 221 rl_add_undo (UNDO_INSERT, start, end, (char *)NULL); 222 rl_end_undo_group (); 223 } 224 return 0; 225} 226 227/* Revert the current line to its previous state. */ 228int 229rl_revert_line (count, key) 230 int count, key; 231{ 232 if (!rl_undo_list) 233 ding (); 234 else 235 { 236 while (rl_undo_list) 237 rl_do_undo (); 238 } 239 return 0; 240} 241 242/* Do some undoing of things that were done. */ 243int 244rl_undo_command (count, key) 245 int count, key; 246{ 247 if (count < 0) 248 return 0; /* Nothing to do. */ 249 250 while (count) 251 { 252 if (rl_do_undo ()) 253 count--; 254 else 255 { 256 ding (); 257 break; 258 } 259 } 260 return 0; 261} 262