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a2e770db | 1 | ;;; minibuf-eldef.el --- Only show defaults in prompts when applicable -*- lexical-binding: t -*- |
66d058c4 | 2 | ;; |
ab422c4d | 3 | ;; Copyright (C) 2000-2013 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 | ||
eb3fa2cf | 10 | ;; GNU Emacs is free software: you can redistribute it and/or modify |
66d058c4 | 11 | ;; it under the terms of the GNU General Public License as published by |
eb3fa2cf GM |
12 | ;; the Free Software Foundation, either version 3 of the License, or |
13 | ;; (at your option) any later version. | |
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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 | |
eb3fa2cf | 21 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. |
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22 | |
23 | ;;; Commentary: | |
24 | ;; | |
25 | ;; Defines the mode `minibuffer-electric-default-mode'. | |
26 | ;; | |
27 | ;; When active, minibuffer prompts that show a default value only show | |
28 | ;; the default when it's applicable -- that is, when hitting RET would | |
29 | ;; yield the default value. If the user modifies the input such that | |
30 | ;; hitting RET would enter a non-default value, the prompt is modified | |
31 | ;; to remove the default indication (which is restored if the input is | |
32 | ;; ever restore to the match the initial input). | |
33 | ||
34 | ;;; Code: | |
35 | ||
7d806bfe | 36 | (defvar minibuffer-eldef-shorten-default) |
a2e770db | 37 | |
7d806bfe | 38 | (defun minibuffer-default--in-prompt-regexps () |
a2e770db SM |
39 | `(("\\( (default\\(?: is\\)? \\(.*\\))\\):? \\'" |
40 | 1 ,(if minibuffer-eldef-shorten-default " [\\2]")) | |
2f108463 | 41 | ("([^(]+?\\(, default\\(?: is\\)? \\(.*\\)\\)):? \\'" 1) |
7d806bfe CY |
42 | ("\\( \\[.*\\]\\):? *\\'" 1))) |
43 | ||
44 | (defcustom minibuffer-eldef-shorten-default nil | |
45 | "If non-nil, shorten \"(default ...)\" to \"[...]\" in minibuffer prompts." | |
46 | :set (lambda (symbol value) | |
47 | (set-default symbol value) | |
48 | (setq-default minibuffer-default-in-prompt-regexps | |
49 | (minibuffer-default--in-prompt-regexps))) | |
50 | :type 'boolean | |
51 | :group 'minibuffer | |
52 | :version "24.3") | |
53 | ||
54 | (defvar minibuffer-default-in-prompt-regexps | |
55 | (minibuffer-default--in-prompt-regexps) | |
fb7ada5f | 56 | "A list of regexps matching the parts of minibuffer prompts showing defaults. |
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57 | When `minibuffer-electric-default-mode' is active, these regexps are |
58 | used to identify the portions of prompts to elide. | |
59 | ||
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60 | Each entry is of the form (REGEXP MATCH-NUM &optional REWRITE), |
61 | where REGEXP should match the default part of the prompt, | |
62 | MATCH-NUM is the subgroup that matched the actual default indicator, | |
63 | and REWRITE, if present, is a string to pass to `replace-match' that | |
64 | should be displayed in its place.") | |
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65 | |
66 | \f | |
67 | ;;; Internal variables | |
68 | ||
69 | ;; A list of minibuffers to which we've added a post-command-hook. | |
70 | (defvar minibuf-eldef-frobbed-minibufs nil) | |
f1180544 | 71 | |
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72 | ;;; The following are all local variables in the minibuffer |
73 | ||
74 | ;; Input pre-inserted into the minibuffer before the user can edit it. | |
75 | (defvar minibuf-eldef-initial-input) | |
76 | (make-variable-buffer-local 'minibuf-eldef-initial-input) | |
77 | ;; and the length of the buffer with it inserted. | |
78 | (defvar minibuf-eldef-initial-buffer-length) | |
79 | (make-variable-buffer-local 'minibuf-eldef-initial-buffer-length) | |
80 | ||
81 | ;; True if the current minibuffer prompt contains the default spec. | |
82 | (defvar minibuf-eldef-showing-default-in-prompt) | |
83 | (make-variable-buffer-local 'minibuf-eldef-showing-default-in-prompt) | |
84 | ||
85 | ;; An overlay covering the default portion of the prompt | |
86 | (defvar minibuf-eldef-overlay) | |
87 | (make-variable-buffer-local 'minibuf-eldef-overlay) | |
88 | ||
89 | \f | |
90 | ;;; Hook functions | |
91 | ||
92 | ;; This function goes on minibuffer-setup-hook | |
93 | (defun minibuf-eldef-setup-minibuffer () | |
94 | "Set up a minibuffer for `minibuffer-electric-default-mode'. | |
95 | The prompt and initial input should already have been inserted." | |
8bbb7c70 | 96 | (let ((regexps minibuffer-default-in-prompt-regexps) |
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97 | (match nil) |
98 | (inhibit-point-motion-hooks t)) | |
99 | (save-excursion | |
100 | (save-restriction | |
a2e770db | 101 | ;; Narrow to only the prompt. |
66d058c4 | 102 | (goto-char (point-min)) |
8bbb7c70 | 103 | (narrow-to-region (point) (minibuffer-prompt-end)) |
a2e770db | 104 | ;; See if the prompt contains a default input indicator. |
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105 | (while regexps |
106 | (setq match (pop regexps)) | |
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107 | (cond |
108 | ((not (re-search-forward (if (stringp match) match (car match)) | |
109 | nil t)) | |
110 | ;; No match yet, try the next rule. | |
111 | (setq match nil)) | |
112 | ((and (consp (cdr-safe match)) (nth 2 match)) | |
113 | ;; Matched a replacement rule. | |
114 | (let* ((inhibit-read-only t) | |
115 | (buffer-undo-list t) | |
116 | (submatch (nth 1 match)) | |
117 | (replacement (nth 2 match)) | |
118 | (props (text-properties-at (match-beginning submatch)))) | |
119 | (replace-match replacement nil nil nil submatch) | |
120 | (set-text-properties (match-beginning submatch) | |
121 | (match-end submatch) | |
122 | props) | |
123 | ;; Replacement done, now keep trying with subsequent rules. | |
124 | (setq match nil) | |
125 | (goto-char (point-min)))) | |
126 | ;; Matched a non-replacement (i.e. electric hide) rule, no need to | |
127 | ;; keep trying. | |
128 | (t (setq regexps nil)))))) | |
66d058c4 | 129 | (if (not match) |
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130 | ;; No match for electric hiding, so just make sure our |
131 | ;; post-command-hook isn't left around. | |
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132 | (remove-hook 'post-command-hook #'minibuf-eldef-update-minibuffer t) |
133 | ;; Yup; set things up so we can frob the prompt as the state of | |
134 | ;; the input string changes. | |
135 | (setq match (if (consp match) (cdr match) 0)) | |
a2e770db | 136 | (setq match (if (consp match) (car match) match)) |
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137 | (setq minibuf-eldef-overlay |
138 | (make-overlay (match-beginning match) (match-end match))) | |
139 | (setq minibuf-eldef-showing-default-in-prompt t) | |
140 | (setq minibuf-eldef-initial-input | |
8bbb7c70 | 141 | (minibuffer-contents-no-properties)) |
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142 | (setq minibuf-eldef-initial-buffer-length (point-max)) |
143 | (add-to-list 'minibuf-eldef-frobbed-minibufs (current-buffer)) | |
144 | (add-hook 'post-command-hook #'minibuf-eldef-update-minibuffer nil t)))) | |
145 | ||
146 | ;; post-command-hook to swap prompts when necessary | |
147 | (defun minibuf-eldef-update-minibuffer () | |
148 | "Update a minibuffer's prompt to include a default only when applicable. | |
149 | This is intended to be used as a minibuffer post-command-hook for | |
150 | `minibuffer-electric-default-mode'; the minibuffer should have already | |
151 | been set up by `minibuf-eldef-setup-minibuffer'." | |
152 | (unless (eq minibuf-eldef-showing-default-in-prompt | |
153 | (and (= (point-max) minibuf-eldef-initial-buffer-length) | |
8bbb7c70 | 154 | (string-equal (minibuffer-contents-no-properties) |
66d058c4 | 155 | minibuf-eldef-initial-input))) |
4b5c89ee | 156 | ;; Swap state. |
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157 | (setq minibuf-eldef-showing-default-in-prompt |
158 | (not minibuf-eldef-showing-default-in-prompt)) | |
4b5c89ee SM |
159 | (overlay-put minibuf-eldef-overlay 'invisible |
160 | (not minibuf-eldef-showing-default-in-prompt)))) | |
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161 | |
162 | \f | |
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163 | ;;;###autoload |
164 | (define-minor-mode minibuffer-electric-default-mode | |
35cd0213 | 165 | "Toggle Minibuffer Electric Default mode. |
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166 | With a prefix argument ARG, enable Minibuffer Electric Default |
167 | mode if ARG is positive, and disable it otherwise. If called | |
168 | from Lisp, enable the mode if ARG is omitted or nil. | |
169 | ||
170 | Minibuffer Electric Default mode is a global minor mode. When | |
171 | enabled, minibuffer prompts that show a default value only show | |
172 | the default when it's applicable -- that is, when hitting RET | |
173 | would yield the default value. If the user modifies the input | |
174 | such that hitting RET would enter a non-default value, the prompt | |
175 | is modified to remove the default indication." | |
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176 | :global t |
177 | :group 'minibuffer | |
178 | (if minibuffer-electric-default-mode | |
179 | ;; Enable the mode | |
180 | (add-hook 'minibuffer-setup-hook 'minibuf-eldef-setup-minibuffer) | |
181 | ;; Disable the mode | |
182 | (remove-hook 'minibuffer-setup-hook 'minibuf-eldef-setup-minibuffer) | |
183 | ;; Remove our entry from any post-command-hook variable's it's still in | |
184 | (dolist (minibuf minibuf-eldef-frobbed-minibufs) | |
185 | (with-current-buffer minibuf | |
186 | (remove-hook 'post-command-hook #'minibuf-eldef-update-minibuffer t))) | |
187 | (setq minibuf-eldef-frobbed-minibufs nil))) | |
188 | ||
189 | ||
190 | (provide 'minibuf-eldef) | |
191 | ||
192 | ;;; minibuf-eldef.el ends here |