1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
|
;;; rmc.el --- read from a multiple choice question -*- lexical-binding: t -*-
;; Copyright (C) 2016-2020 Free Software Foundation, Inc.
;; Maintainer: emacs-devel@gnu.org
;; This file is part of GNU Emacs.
;; GNU Emacs 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.
;; GNU Emacs 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 GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
;;; Commentary:
;;; Code:
(require 'seq)
;;;###autoload
(defun read-multiple-choice (prompt choices)
"Ask user a multiple choice question.
PROMPT should be a string that will be displayed as the prompt.
CHOICES is a list of (KEY NAME [DESCRIPTION]). KEY is a
character to be entered. NAME is a short name for the entry to
be displayed while prompting (if there's room, it might be
shortened). DESCRIPTION is an optional longer explanation that
will be displayed in a help buffer if the user requests more
help.
This function translates user input into responses by consulting
the bindings in `query-replace-map'; see the documentation of
that variable for more information. In this case, the useful
bindings are `recenter', `scroll-up', and `scroll-down'. If the
user enters `recenter', `scroll-up', or `scroll-down' responses,
perform the requested window recentering or scrolling and ask
again.
When `use-dialog-box' is t (the default), this function can pop
up a dialog window to collect the user input. That functionality
requires `display-popup-menus-p' to return t. Otherwise, a
text dialog will be used.
The return value is the matching entry from the CHOICES list.
Usage example:
\(read-multiple-choice \"Continue connecting?\"
\\='((?a \"always\")
(?s \"session only\")
(?n \"no\")))"
(let* ((altered-names nil)
(full-prompt
(format
"%s (%s): "
prompt
(mapconcat
(lambda (elem)
(let* ((name (cadr elem))
(pos (seq-position name (car elem)))
(altered-name
(cond
;; Not in the name string.
((not pos)
(format "[%c] %s" (car elem) name))
;; The prompt character is in the name, so highlight
;; it on graphical terminals...
((display-supports-face-attributes-p
'(:underline t) (window-frame))
(setq name (copy-sequence name))
(put-text-property pos (1+ pos)
'face 'read-multiple-choice-face
name)
name)
;; And put it in [bracket] on non-graphical terminals.
(t
(concat
(substring name 0 pos)
"["
(upcase (substring name pos (1+ pos)))
"]"
(substring name (1+ pos)))))))
(push (cons (car elem) altered-name)
altered-names)
altered-name))
(append choices '((?? "?")))
", ")))
tchar buf wrong-char answer)
(save-window-excursion
(save-excursion
(while (not tchar)
(message "%s%s"
(if wrong-char
"Invalid choice. "
"")
full-prompt)
(setq tchar
(if (and (display-popup-menus-p)
last-input-event ; not during startup
(consp last-nonmenu-event)
use-dialog-box)
(x-popup-dialog
t
(cons prompt
(mapcar
(lambda (elem)
(cons (capitalize (cadr elem))
(car elem)))
choices)))
(condition-case nil
(let ((cursor-in-echo-area t))
(read-event))
(error nil))))
(setq answer (lookup-key query-replace-map (vector tchar) t))
(setq tchar
(cond
((eq answer 'recenter)
(recenter) t)
((eq answer 'scroll-up)
(ignore-errors (scroll-up-command)) t)
((eq answer 'scroll-down)
(ignore-errors (scroll-down-command)) t)
((eq answer 'scroll-other-window)
(ignore-errors (scroll-other-window)) t)
((eq answer 'scroll-other-window-down)
(ignore-errors (scroll-other-window-down)) t)
(t tchar)))
(when (eq tchar t)
(setq wrong-char nil
tchar nil))
;; The user has entered an invalid choice, so display the
;; help messages.
(when (and (not (eq tchar nil))
(not (assq tchar choices)))
(setq wrong-char (not (memq tchar '(?? ?\C-h)))
tchar nil)
(when wrong-char
(ding))
(with-help-window (setq buf (get-buffer-create
"*Multiple Choice Help*"))
(with-current-buffer buf
(erase-buffer)
(pop-to-buffer buf)
(insert prompt "\n\n")
(let* ((columns (/ (window-width) 25))
(fill-column 21)
(times 0)
(start (point)))
(dolist (elem choices)
(goto-char start)
(unless (zerop times)
(if (zerop (mod times columns))
;; Go to the next "line".
(goto-char (setq start (point-max)))
;; Add padding.
(while (not (eobp))
(end-of-line)
(insert (make-string (max (- (* (mod times columns)
(+ fill-column 4))
(current-column))
0)
?\s))
(forward-line 1))))
(setq times (1+ times))
(let ((text
(with-temp-buffer
(insert (format
"%c: %s\n"
(car elem)
(cdr (assq (car elem) altered-names))))
(fill-region (point-min) (point-max))
(when (nth 2 elem)
(let ((start (point)))
(insert (nth 2 elem))
(unless (bolp)
(insert "\n"))
(fill-region start (point-max))))
(buffer-string))))
(goto-char start)
(dolist (line (split-string text "\n"))
(end-of-line)
(if (bolp)
(insert line "\n")
(insert line))
(forward-line 1)))))))))))
(when (buffer-live-p buf)
(kill-buffer buf))
(assq tchar choices)))
(provide 'rmc)
;;; rmc.el ends here
|
