diff options
Diffstat (limited to 'readline/undo.c')
| -rw-r--r-- | readline/undo.c | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/readline/undo.c b/readline/undo.c new file mode 100644 index 00000000000..28ebcc85b93 --- /dev/null +++ b/readline/undo.c @@ -0,0 +1,260 @@ +/* readline.c -- a general facility for reading lines of input + with emacs style editing and completion. */ + +/* Copyright (C) 1987, 1989, 1992 Free Software Foundation, Inc. + + This file is part of the GNU Readline Library, a library for + reading lines of text with interactive input and history editing. + + The GNU Readline Library is free software; you can redistribute it + and/or modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 1, or + (at your option) any later version. + + The GNU Readline Library is distributed in the hope that it will be + useful, but WITHOUT ANY WARRANTY; without even the implied warranty + of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + The GNU General Public License is often shipped with GNU software, and + is generally kept in a file called COPYING or LICENSE. If you do not + have a copy of the license, write to the Free Software Foundation, + 675 Mass Ave, Cambridge, MA 02139, USA. */ +#define READLINE_LIBRARY + +#if defined (HAVE_CONFIG_H) +# include <config.h> +#endif + +#include <sys/types.h> + +#if defined (HAVE_UNISTD_H) +# include <unistd.h> /* for _POSIX_VERSION */ +#endif /* HAVE_UNISTD_H */ + +#if defined (HAVE_STDLIB_H) +# include <stdlib.h> +#else +# include "ansi_stdlib.h" +#endif /* HAVE_STDLIB_H */ + +#include <stdio.h> + +/* System-specific feature definitions and include files. */ +#include "rldefs.h" + +/* Some standard library routines. */ +#include "readline.h" +#include "history.h" + +#define SWAP(s, e) do { int t; t = s; s = e; e = t; } while (0) + +/* Non-zero tells rl_delete_text and rl_insert_text to not add to + the undo list. */ +int _rl_doing_an_undo = 0; + +/* How many unclosed undo groups we currently have. */ +int _rl_undo_group_level = 0; + +/* The current undo list for THE_LINE. */ +UNDO_LIST *rl_undo_list = (UNDO_LIST *)NULL; + +/* **************************************************************** */ +/* */ +/* Undo, and Undoing */ +/* */ +/* **************************************************************** */ + +/* Remember how to undo something. Concatenate some undos if that + seems right. */ +void +rl_add_undo (what, start, end, text) + enum undo_code what; + int start, end; + char *text; +{ + UNDO_LIST *temp = (UNDO_LIST *)xmalloc (sizeof (UNDO_LIST)); + temp->what = what; + temp->start = start; + temp->end = end; + temp->text = text; + temp->next = rl_undo_list; + rl_undo_list = temp; +} + +/* Free the existing undo list. */ +void +free_undo_list () +{ + while (rl_undo_list) + { + UNDO_LIST *release = rl_undo_list; + rl_undo_list = rl_undo_list->next; + + if (release->what == UNDO_DELETE) + free (release->text); + + free (release); + } + rl_undo_list = (UNDO_LIST *)NULL; +} + +/* Undo the next thing in the list. Return 0 if there + is nothing to undo, or non-zero if there was. */ +int +rl_do_undo () +{ + UNDO_LIST *release; + int waiting_for_begin = 0; + int start, end; + +#define TRANS(i) ((i) == -1 ? rl_point : ((i) == -2 ? rl_end : (i))) + + do + { + if (!rl_undo_list) + return (0); + + _rl_doing_an_undo = 1; + + /* To better support vi-mode, a start or end value of -1 means + rl_point, and a value of -2 means rl_end. */ + if (rl_undo_list->what == UNDO_DELETE || rl_undo_list->what == UNDO_INSERT) + { + start = TRANS (rl_undo_list->start); + end = TRANS (rl_undo_list->end); + } + + switch (rl_undo_list->what) + { + /* Undoing deletes means inserting some text. */ + case UNDO_DELETE: + rl_point = start; + rl_insert_text (rl_undo_list->text); + free (rl_undo_list->text); + break; + + /* Undoing inserts means deleting some text. */ + case UNDO_INSERT: + rl_delete_text (start, end); + rl_point = start; + break; + + /* Undoing an END means undoing everything 'til we get to a BEGIN. */ + case UNDO_END: + waiting_for_begin++; + break; + + /* Undoing a BEGIN means that we are done with this group. */ + case UNDO_BEGIN: + if (waiting_for_begin) + waiting_for_begin--; + else + ding (); + break; + } + + _rl_doing_an_undo = 0; + + release = rl_undo_list; + rl_undo_list = rl_undo_list->next; + free (release); + } + while (waiting_for_begin); + + return (1); +} +#undef TRANS + +int +_rl_fix_last_undo_of_type (type, start, end) + int type, start, end; +{ + UNDO_LIST *rl; + + for (rl = rl_undo_list; rl; rl = rl->next) + { + if (rl->what == type) + { + rl->start = start; + rl->end = end; + return 0; + } + } + return 1; +} + +/* Begin a group. Subsequent undos are undone as an atomic operation. */ +int +rl_begin_undo_group () +{ + rl_add_undo (UNDO_BEGIN, 0, 0, 0); + _rl_undo_group_level++; + return 0; +} + +/* End an undo group started with rl_begin_undo_group (). */ +int +rl_end_undo_group () +{ + rl_add_undo (UNDO_END, 0, 0, 0); + _rl_undo_group_level--; + return 0; +} + +/* Save an undo entry for the text from START to END. */ +int +rl_modifying (start, end) + int start, end; +{ + if (start > end) + { + SWAP (start, end); + } + + if (start != end) + { + char *temp = rl_copy_text (start, end); + rl_begin_undo_group (); + rl_add_undo (UNDO_DELETE, start, end, temp); + rl_add_undo (UNDO_INSERT, start, end, (char *)NULL); + rl_end_undo_group (); + } + return 0; +} + +/* Revert the current line to its previous state. */ +int +rl_revert_line (count, key) + int count, key; +{ + if (!rl_undo_list) + ding (); + else + { + while (rl_undo_list) + rl_do_undo (); + } + return 0; +} + +/* Do some undoing of things that were done. */ +int +rl_undo_command (count, key) + int count, key; +{ + if (count < 0) + return 0; /* Nothing to do. */ + + while (count) + { + if (rl_do_undo ()) + count--; + else + { + ding (); + break; + } + } + return 0; +} |