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1 | ;;; minibuf-eldef.el --- Only show defaults in prompts when applicable |
2 | ;; | |
8bbb7c70 | 3 | ;; Copyright (C) 2000, 2001 Free Software Foundation, Inc. |
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4 | ;; |
5 | ;; Author: Miles Bader <miles@gnu.org> | |
6 | ;; Keywords: convenience | |
7 | ||
8 | ;; This file is part of GNU Emacs. | |
9 | ||
10 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
11 | ;; it under the terms of the GNU General Public License as published by | |
12 | ;; the Free Software Foundation; either version 2, or (at your option) | |
13 | ;; any later version. | |
14 | ||
15 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
16 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | ;; GNU General Public License for more details. | |
19 | ||
20 | ;; You should have received a copy of the GNU General Public License | |
21 | ;; along with GNU Emacs; see the file COPYING. If not, write to the | |
22 | ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
23 | ;; Boston, MA 02111-1307, USA. | |
24 | ||
25 | ;;; Commentary: | |
26 | ;; | |
27 | ;; Defines the mode `minibuffer-electric-default-mode'. | |
28 | ;; | |
29 | ;; When active, minibuffer prompts that show a default value only show | |
30 | ;; the default when it's applicable -- that is, when hitting RET would | |
31 | ;; yield the default value. If the user modifies the input such that | |
32 | ;; hitting RET would enter a non-default value, the prompt is modified | |
33 | ;; to remove the default indication (which is restored if the input is | |
34 | ;; ever restore to the match the initial input). | |
35 | ||
36 | ;;; Code: | |
37 | ||
38 | (defvar minibuffer-default-in-prompt-regexps | |
39 | '(("\\( (default\\>.*)\\):? \\'" . 1)) | |
40 | "*A list of regexps matching the parts of minibuffer prompts showing defaults. | |
41 | When `minibuffer-electric-default-mode' is active, these regexps are | |
42 | used to identify the portions of prompts to elide. | |
43 | ||
44 | Each entry is either a string, which should be a regexp matching the | |
45 | default portion of the prompt, or a cons cell, who's car is a regexp | |
46 | matching the default part of the prompt, and who's cdr indicates the | |
47 | regexp subexpression that matched.") | |
48 | ||
49 | \f | |
50 | ;;; Internal variables | |
51 | ||
52 | ;; A list of minibuffers to which we've added a post-command-hook. | |
53 | (defvar minibuf-eldef-frobbed-minibufs nil) | |
f1180544 | 54 | |
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55 | ;;; The following are all local variables in the minibuffer |
56 | ||
57 | ;; Input pre-inserted into the minibuffer before the user can edit it. | |
58 | (defvar minibuf-eldef-initial-input) | |
59 | (make-variable-buffer-local 'minibuf-eldef-initial-input) | |
60 | ;; and the length of the buffer with it inserted. | |
61 | (defvar minibuf-eldef-initial-buffer-length) | |
62 | (make-variable-buffer-local 'minibuf-eldef-initial-buffer-length) | |
63 | ||
64 | ;; True if the current minibuffer prompt contains the default spec. | |
65 | (defvar minibuf-eldef-showing-default-in-prompt) | |
66 | (make-variable-buffer-local 'minibuf-eldef-showing-default-in-prompt) | |
67 | ||
68 | ;; An overlay covering the default portion of the prompt | |
69 | (defvar minibuf-eldef-overlay) | |
70 | (make-variable-buffer-local 'minibuf-eldef-overlay) | |
71 | ||
72 | \f | |
73 | ;;; Hook functions | |
74 | ||
75 | ;; This function goes on minibuffer-setup-hook | |
76 | (defun minibuf-eldef-setup-minibuffer () | |
77 | "Set up a minibuffer for `minibuffer-electric-default-mode'. | |
78 | The prompt and initial input should already have been inserted." | |
8bbb7c70 | 79 | (let ((regexps minibuffer-default-in-prompt-regexps) |
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80 | (match nil) |
81 | (inhibit-point-motion-hooks t)) | |
82 | (save-excursion | |
83 | (save-restriction | |
84 | ;; Narrow to only the prompt | |
85 | (goto-char (point-min)) | |
8bbb7c70 | 86 | (narrow-to-region (point) (minibuffer-prompt-end)) |
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87 | ;; See the prompt contains a default input indicator |
88 | (while regexps | |
89 | (setq match (pop regexps)) | |
90 | (if (re-search-forward (if (stringp match) match (car match)) nil t) | |
91 | (setq regexps nil) | |
92 | (setq match nil))))) | |
93 | (if (not match) | |
94 | ;; Nope, so just make sure our post-command-hook isn't left around. | |
95 | (remove-hook 'post-command-hook #'minibuf-eldef-update-minibuffer t) | |
96 | ;; Yup; set things up so we can frob the prompt as the state of | |
97 | ;; the input string changes. | |
98 | (setq match (if (consp match) (cdr match) 0)) | |
99 | (setq minibuf-eldef-overlay | |
100 | (make-overlay (match-beginning match) (match-end match))) | |
101 | (setq minibuf-eldef-showing-default-in-prompt t) | |
102 | (setq minibuf-eldef-initial-input | |
8bbb7c70 | 103 | (minibuffer-contents-no-properties)) |
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104 | (setq minibuf-eldef-initial-buffer-length (point-max)) |
105 | (add-to-list 'minibuf-eldef-frobbed-minibufs (current-buffer)) | |
106 | (add-hook 'post-command-hook #'minibuf-eldef-update-minibuffer nil t)))) | |
107 | ||
108 | ;; post-command-hook to swap prompts when necessary | |
109 | (defun minibuf-eldef-update-minibuffer () | |
110 | "Update a minibuffer's prompt to include a default only when applicable. | |
111 | This is intended to be used as a minibuffer post-command-hook for | |
112 | `minibuffer-electric-default-mode'; the minibuffer should have already | |
113 | been set up by `minibuf-eldef-setup-minibuffer'." | |
114 | (unless (eq minibuf-eldef-showing-default-in-prompt | |
115 | (and (= (point-max) minibuf-eldef-initial-buffer-length) | |
8bbb7c70 | 116 | (string-equal (minibuffer-contents-no-properties) |
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117 | minibuf-eldef-initial-input))) |
118 | ;; swap state | |
119 | (setq minibuf-eldef-showing-default-in-prompt | |
120 | (not minibuf-eldef-showing-default-in-prompt)) | |
121 | (cond (minibuf-eldef-showing-default-in-prompt | |
122 | (overlay-put minibuf-eldef-overlay 'invisible nil) | |
123 | (overlay-put minibuf-eldef-overlay 'intangible nil)) | |
124 | (t | |
125 | (overlay-put minibuf-eldef-overlay 'invisible t) | |
126 | (overlay-put minibuf-eldef-overlay 'intangible t))))) | |
127 | ||
128 | \f | |
129 | ;;; Note this definition must be at the end of the file, because | |
130 | ;;; `define-minor-mode' actually calls the mode-function if the | |
131 | ;;; associated variable is non-nil, which requires that all needed | |
132 | ;;; functions be already defined. [This is arguably a bug in d-m-m] | |
133 | ;;;###autoload | |
134 | (define-minor-mode minibuffer-electric-default-mode | |
35cd0213 | 135 | "Toggle Minibuffer Electric Default mode. |
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136 | When active, minibuffer prompts that show a default value only show the |
137 | default when it's applicable -- that is, when hitting RET would yield | |
138 | the default value. If the user modifies the input such that hitting RET | |
139 | would enter a non-default value, the prompt is modified to remove the | |
140 | default indication. | |
141 | ||
142 | With prefix argument ARG, turn on if positive, otherwise off. | |
143 | Returns non-nil if the new state is enabled." | |
144 | :global t | |
145 | :group 'minibuffer | |
146 | (if minibuffer-electric-default-mode | |
147 | ;; Enable the mode | |
148 | (add-hook 'minibuffer-setup-hook 'minibuf-eldef-setup-minibuffer) | |
149 | ;; Disable the mode | |
150 | (remove-hook 'minibuffer-setup-hook 'minibuf-eldef-setup-minibuffer) | |
151 | ;; Remove our entry from any post-command-hook variable's it's still in | |
152 | (dolist (minibuf minibuf-eldef-frobbed-minibufs) | |
153 | (with-current-buffer minibuf | |
154 | (remove-hook 'post-command-hook #'minibuf-eldef-update-minibuffer t))) | |
155 | (setq minibuf-eldef-frobbed-minibufs nil))) | |
156 | ||
157 | ||
158 | (provide 'minibuf-eldef) | |
159 | ||
160 | ;;; minibuf-eldef.el ends here |