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a2e770db | 1 | ;;; minibuf-eldef.el --- Only show defaults in prompts when applicable -*- lexical-binding: t -*- |
66d058c4 | 2 | ;; |
acaf905b | 3 | ;; Copyright (C) 2000-2012 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 () |
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39 | `(("\\( (default\\(?: is\\)? \\(.*\\))\\):? \\'" |
40 | 1 ,(if minibuffer-eldef-shorten-default " [\\2]")) | |
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41 | ("\\( \\[.*\\]\\):? *\\'" 1))) |
42 | ||
43 | (defcustom minibuffer-eldef-shorten-default nil | |
44 | "If non-nil, shorten \"(default ...)\" to \"[...]\" in minibuffer prompts." | |
45 | :set (lambda (symbol value) | |
46 | (set-default symbol value) | |
47 | (setq-default minibuffer-default-in-prompt-regexps | |
48 | (minibuffer-default--in-prompt-regexps))) | |
49 | :type 'boolean | |
50 | :group 'minibuffer | |
51 | :version "24.3") | |
52 | ||
53 | (defvar minibuffer-default-in-prompt-regexps | |
54 | (minibuffer-default--in-prompt-regexps) | |
fb7ada5f | 55 | "A list of regexps matching the parts of minibuffer prompts showing defaults. |
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56 | When `minibuffer-electric-default-mode' is active, these regexps are |
57 | used to identify the portions of prompts to elide. | |
58 | ||
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59 | Each entry is of the form (REGEXP MATCH-NUM &optional REWRITE), |
60 | where REGEXP should match the default part of the prompt, | |
61 | MATCH-NUM is the subgroup that matched the actual default indicator, | |
62 | and REWRITE, if present, is a string to pass to `replace-match' that | |
63 | should be displayed in its place.") | |
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64 | |
65 | \f | |
66 | ;;; Internal variables | |
67 | ||
68 | ;; A list of minibuffers to which we've added a post-command-hook. | |
69 | (defvar minibuf-eldef-frobbed-minibufs nil) | |
f1180544 | 70 | |
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71 | ;;; The following are all local variables in the minibuffer |
72 | ||
73 | ;; Input pre-inserted into the minibuffer before the user can edit it. | |
74 | (defvar minibuf-eldef-initial-input) | |
75 | (make-variable-buffer-local 'minibuf-eldef-initial-input) | |
76 | ;; and the length of the buffer with it inserted. | |
77 | (defvar minibuf-eldef-initial-buffer-length) | |
78 | (make-variable-buffer-local 'minibuf-eldef-initial-buffer-length) | |
79 | ||
80 | ;; True if the current minibuffer prompt contains the default spec. | |
81 | (defvar minibuf-eldef-showing-default-in-prompt) | |
82 | (make-variable-buffer-local 'minibuf-eldef-showing-default-in-prompt) | |
83 | ||
84 | ;; An overlay covering the default portion of the prompt | |
85 | (defvar minibuf-eldef-overlay) | |
86 | (make-variable-buffer-local 'minibuf-eldef-overlay) | |
87 | ||
88 | \f | |
89 | ;;; Hook functions | |
90 | ||
91 | ;; This function goes on minibuffer-setup-hook | |
92 | (defun minibuf-eldef-setup-minibuffer () | |
93 | "Set up a minibuffer for `minibuffer-electric-default-mode'. | |
94 | The prompt and initial input should already have been inserted." | |
8bbb7c70 | 95 | (let ((regexps minibuffer-default-in-prompt-regexps) |
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96 | (match nil) |
97 | (inhibit-point-motion-hooks t)) | |
98 | (save-excursion | |
99 | (save-restriction | |
a2e770db | 100 | ;; Narrow to only the prompt. |
66d058c4 | 101 | (goto-char (point-min)) |
8bbb7c70 | 102 | (narrow-to-region (point) (minibuffer-prompt-end)) |
a2e770db | 103 | ;; See if the prompt contains a default input indicator. |
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104 | (while regexps |
105 | (setq match (pop regexps)) | |
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106 | (cond |
107 | ((not (re-search-forward (if (stringp match) match (car match)) | |
108 | nil t)) | |
109 | ;; No match yet, try the next rule. | |
110 | (setq match nil)) | |
111 | ((and (consp (cdr-safe match)) (nth 2 match)) | |
112 | ;; Matched a replacement rule. | |
113 | (let* ((inhibit-read-only t) | |
114 | (buffer-undo-list t) | |
115 | (submatch (nth 1 match)) | |
116 | (replacement (nth 2 match)) | |
117 | (props (text-properties-at (match-beginning submatch)))) | |
118 | (replace-match replacement nil nil nil submatch) | |
119 | (set-text-properties (match-beginning submatch) | |
120 | (match-end submatch) | |
121 | props) | |
122 | ;; Replacement done, now keep trying with subsequent rules. | |
123 | (setq match nil) | |
124 | (goto-char (point-min)))) | |
125 | ;; Matched a non-replacement (i.e. electric hide) rule, no need to | |
126 | ;; keep trying. | |
127 | (t (setq regexps nil)))))) | |
66d058c4 | 128 | (if (not match) |
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129 | ;; No match for electric hiding, so just make sure our |
130 | ;; post-command-hook isn't left around. | |
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131 | (remove-hook 'post-command-hook #'minibuf-eldef-update-minibuffer t) |
132 | ;; Yup; set things up so we can frob the prompt as the state of | |
133 | ;; the input string changes. | |
134 | (setq match (if (consp match) (cdr match) 0)) | |
a2e770db | 135 | (setq match (if (consp match) (car match) match)) |
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136 | (setq minibuf-eldef-overlay |
137 | (make-overlay (match-beginning match) (match-end match))) | |
138 | (setq minibuf-eldef-showing-default-in-prompt t) | |
139 | (setq minibuf-eldef-initial-input | |
8bbb7c70 | 140 | (minibuffer-contents-no-properties)) |
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141 | (setq minibuf-eldef-initial-buffer-length (point-max)) |
142 | (add-to-list 'minibuf-eldef-frobbed-minibufs (current-buffer)) | |
143 | (add-hook 'post-command-hook #'minibuf-eldef-update-minibuffer nil t)))) | |
144 | ||
145 | ;; post-command-hook to swap prompts when necessary | |
146 | (defun minibuf-eldef-update-minibuffer () | |
147 | "Update a minibuffer's prompt to include a default only when applicable. | |
148 | This is intended to be used as a minibuffer post-command-hook for | |
149 | `minibuffer-electric-default-mode'; the minibuffer should have already | |
150 | been set up by `minibuf-eldef-setup-minibuffer'." | |
151 | (unless (eq minibuf-eldef-showing-default-in-prompt | |
152 | (and (= (point-max) minibuf-eldef-initial-buffer-length) | |
8bbb7c70 | 153 | (string-equal (minibuffer-contents-no-properties) |
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154 | minibuf-eldef-initial-input))) |
155 | ;; swap state | |
156 | (setq minibuf-eldef-showing-default-in-prompt | |
157 | (not minibuf-eldef-showing-default-in-prompt)) | |
158 | (cond (minibuf-eldef-showing-default-in-prompt | |
159 | (overlay-put minibuf-eldef-overlay 'invisible nil) | |
160 | (overlay-put minibuf-eldef-overlay 'intangible nil)) | |
161 | (t | |
162 | (overlay-put minibuf-eldef-overlay 'invisible t) | |
163 | (overlay-put minibuf-eldef-overlay 'intangible t))))) | |
164 | ||
165 | \f | |
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166 | ;;;###autoload |
167 | (define-minor-mode minibuffer-electric-default-mode | |
35cd0213 | 168 | "Toggle Minibuffer Electric Default mode. |
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169 | With a prefix argument ARG, enable Minibuffer Electric Default |
170 | mode if ARG is positive, and disable it otherwise. If called | |
171 | from Lisp, enable the mode if ARG is omitted or nil. | |
172 | ||
173 | Minibuffer Electric Default mode is a global minor mode. When | |
174 | enabled, minibuffer prompts that show a default value only show | |
175 | the default when it's applicable -- that is, when hitting RET | |
176 | would yield the default value. If the user modifies the input | |
177 | such that hitting RET would enter a non-default value, the prompt | |
178 | is modified to remove the default indication." | |
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179 | :global t |
180 | :group 'minibuffer | |
181 | (if minibuffer-electric-default-mode | |
182 | ;; Enable the mode | |
183 | (add-hook 'minibuffer-setup-hook 'minibuf-eldef-setup-minibuffer) | |
184 | ;; Disable the mode | |
185 | (remove-hook 'minibuffer-setup-hook 'minibuf-eldef-setup-minibuffer) | |
186 | ;; Remove our entry from any post-command-hook variable's it's still in | |
187 | (dolist (minibuf minibuf-eldef-frobbed-minibufs) | |
188 | (with-current-buffer minibuf | |
189 | (remove-hook 'post-command-hook #'minibuf-eldef-update-minibuffer t))) | |
190 | (setq minibuf-eldef-frobbed-minibufs nil))) | |
191 | ||
192 | ||
193 | (provide 'minibuf-eldef) | |
194 | ||
195 | ;;; minibuf-eldef.el ends here |