diff options
Diffstat (limited to 'undo.c')
| -rw-r--r-- | undo.c | 367 |
1 files changed, 367 insertions, 0 deletions
@@ -0,0 +1,367 @@ +/* undo.c - manage list of changes to lines, offering opportunity to undo them */ + +/* Copyright (C) 1987-2017 Free Software Foundation, Inc. + + This file is part of the GNU Readline Library (Readline), a library + for reading lines of text with interactive input and history editing. + + Readline 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 3 of the License, or + (at your option) any later version. + + Readline 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. + + You should have received a copy of the GNU General Public License + along with Readline. If not, see <http://www.gnu.org/licenses/>. +*/ + +#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" + +#include "rlprivate.h" +#include "xmalloc.h" + +extern void _hs_replace_history_data PARAMS((int, histdata_t *, histdata_t *)); + +extern HIST_ENTRY *_rl_saved_line_for_history; + +/* 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 */ +/* */ +/* **************************************************************** */ + +static UNDO_LIST * +alloc_undo_entry (enum undo_code what, int start, int end, char *text) +{ + UNDO_LIST *temp; + + temp = (UNDO_LIST *)xmalloc (sizeof (UNDO_LIST)); + temp->what = what; + temp->start = start; + temp->end = end; + temp->text = text; + + temp->next = (UNDO_LIST *)NULL; + return temp; +} + +/* Remember how to undo something. Concatenate some undos if that + seems right. */ +void +rl_add_undo (enum undo_code what, int start, int end, char *text) +{ + UNDO_LIST *temp; + + temp = alloc_undo_entry (what, start, end, text); + temp->next = rl_undo_list; + rl_undo_list = temp; +} + +/* Free an UNDO_LIST */ +void +_rl_free_undo_list (UNDO_LIST *ul) +{ + UNDO_LIST *release; + + while (ul) + { + release = ul; + ul = ul->next; + + if (release->what == UNDO_DELETE) + xfree (release->text); + + xfree (release); + } +} + +/* Free the existing undo list. */ +void +rl_free_undo_list (void) +{ + UNDO_LIST *release, *orig_list; + + orig_list = rl_undo_list; + _rl_free_undo_list (rl_undo_list); + rl_undo_list = (UNDO_LIST *)NULL; + _hs_replace_history_data (-1, (histdata_t *)orig_list, (histdata_t *)NULL); +} + +UNDO_LIST * +_rl_copy_undo_entry (UNDO_LIST *entry) +{ + UNDO_LIST *new; + + new = alloc_undo_entry (entry->what, entry->start, entry->end, (char *)NULL); + new->text = entry->text ? savestring (entry->text) : 0; + return new; +} + +UNDO_LIST * +_rl_copy_undo_list (UNDO_LIST *head) +{ + UNDO_LIST *list, *new, *roving, *c; + + if (head == 0) + return head; + + list = head; + new = 0; + while (list) + { + c = _rl_copy_undo_entry (list); + if (new == 0) + roving = new = c; + else + { + roving->next = c; + roving = roving->next; + } + list = list->next; + } + + roving->next = 0; + return new; +} + +/* 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 (void) +{ + UNDO_LIST *release, *search; + int waiting_for_begin, start, end; + HIST_ENTRY *cur, *temp; + +#define TRANS(i) ((i) == -1 ? rl_point : ((i) == -2 ? rl_end : (i))) + + start = end = waiting_for_begin = 0; + do + { + if (rl_undo_list == 0) + return (0); + + _rl_doing_an_undo = 1; + RL_SETSTATE(RL_STATE_UNDOING); + + /* 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_fix_point (1); + rl_insert_text (rl_undo_list->text); + xfree (rl_undo_list->text); + break; + + /* Undoing inserts means deleting some text. */ + case UNDO_INSERT: + rl_delete_text (start, end); + rl_point = start; + _rl_fix_point (1); + 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 + rl_ding (); + break; + } + + _rl_doing_an_undo = 0; + RL_UNSETSTATE(RL_STATE_UNDOING); + + release = rl_undo_list; + rl_undo_list = rl_undo_list->next; + release->next = 0; /* XXX */ + + /* If we are editing a history entry, make sure the change is replicated + in the history entry's line */ + cur = current_history (); + if (cur && cur->data && (UNDO_LIST *)cur->data == release) + { + temp = replace_history_entry (where_history (), rl_line_buffer, (histdata_t)rl_undo_list); + xfree (temp->line); + FREE (temp->timestamp); + xfree (temp); + } + + /* Make sure there aren't any history entries with that undo list */ + _hs_replace_history_data (-1, (histdata_t *)release, (histdata_t *)rl_undo_list); + + /* And make sure this list isn't anywhere in the saved line for history */ + if (_rl_saved_line_for_history && _rl_saved_line_for_history->data) + { + /* Brute force; no finesse here */ + search = (UNDO_LIST *)_rl_saved_line_for_history->data; + if (search == release) + _rl_saved_line_for_history->data = rl_undo_list; + else + { + while (search->next) + { + if (search->next == release) + { + search->next = rl_undo_list; + break; + } + search = search->next; + } + } + } + + xfree (release); + } + while (waiting_for_begin); + + return (1); +} +#undef TRANS + +int +_rl_fix_last_undo_of_type (int type, int start, int 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 (void) +{ + 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 (void) +{ + 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 (int start, int 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 (int count, int key) +{ + if (rl_undo_list == 0) + rl_ding (); + else + { + while (rl_undo_list) + rl_do_undo (); +#if defined (VI_MODE) + if (rl_editing_mode == vi_mode) + rl_point = rl_mark = 0; /* rl_end should be set correctly */ +#endif + } + + return 0; +} + +/* Do some undoing of things that were done. */ +int +rl_undo_command (int count, int key) +{ + if (count < 0) + return 0; /* Nothing to do. */ + + while (count) + { + if (rl_do_undo ()) + count--; + else + { + rl_ding (); + break; + } + } + return 0; +} |