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1 ;;; map-ynp.el --- general-purpose boolean question-asker
3 ;; Copyright (C) 1991, 1992, 1993, 1994, 1995, 2000 Free Software Foundation, Inc.
5 ;; Author: Roland McGrath <roland@gnu.org>
6 ;; Maintainer: FSF
7 ;; Keywords: lisp, extensions
9 ;; This file is part of GNU Emacs.
11 ;; GNU Emacs is free software; you can redistribute it and/or modify
12 ;; it under the terms of the GNU General Public License as published by
13 ;; the Free Software Foundation; either version 2, or (at your option)
14 ;; any later version.
16 ;; GNU Emacs is distributed in the hope that it will be useful,
17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 ;; GNU General Public License for more details.
21 ;; You should have received a copy of the GNU General Public License
22 ;; along with GNU Emacs; see the file COPYING. If not, write to the
23 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
24 ;; Boston, MA 02111-1307, USA.
26 ;;; Commentary:
28 ;; map-y-or-n-p is a general-purpose question-asking function.
29 ;; It asks a series of y/n questions (a la y-or-n-p), and decides to
30 ;; apply an action to each element of a list based on the answer.
31 ;; The nice thing is that you also get some other possible answers
32 ;; to use, reminiscent of query-replace: ! to answer y to all remaining
33 ;; questions; ESC or q to answer n to all remaining questions; . to answer
34 ;; y once and then n for the remainder; and you can get help with C-h.
36 ;;; Code:
38 (defun map-y-or-n-p (prompter actor list &optional help action-alist
39 no-cursor-in-echo-area)
40 "Ask a series of boolean questions.
41 Takes args PROMPTER ACTOR LIST, and optional args HELP and ACTION-ALIST.
43 LIST is a list of objects, or a function of no arguments to return the next
44 object or nil.
46 If PROMPTER is a string, the prompt is \(format PROMPTER OBJECT\). If not
47 a string, PROMPTER is a function of one arg (an object from LIST), which
48 returns a string to be used as the prompt for that object. If the return
49 value is not a string, it may be nil to ignore the object or non-nil to act
50 on the object without asking the user.
52 ACTOR is a function of one arg (an object from LIST),
53 which gets called with each object that the user answers `yes' for.
55 If HELP is given, it is a list (OBJECT OBJECTS ACTION),
56 where OBJECT is a string giving the singular noun for an elt of LIST;
57 OBJECTS is the plural noun for elts of LIST, and ACTION is a transitive
58 verb describing ACTOR. The default is \(\"object\" \"objects\" \"act on\"\).
60 At the prompts, the user may enter y, Y, or SPC to act on that object;
61 n, N, or DEL to skip that object; ! to act on all following objects;
62 ESC or q to exit (skip all following objects); . (period) to act on the
63 current object and then exit; or \\[help-command] to get help.
65 If ACTION-ALIST is given, it is an alist (KEY FUNCTION HELP) of extra keys
66 that will be accepted. KEY is a character; FUNCTION is a function of one
67 arg (an object from LIST); HELP is a string. When the user hits KEY,
68 FUNCTION is called. If it returns non-nil, the object is considered
69 \"acted upon\", and the next object from LIST is processed. If it returns
70 nil, the prompt is repeated for the same object.
72 Final optional argument NO-CURSOR-IN-ECHO-AREA non-nil says not to set
73 `cursor-in-echo-area' while prompting.
75 This function uses `query-replace-map' to define the standard responses,
76 but not all of the responses which `query-replace' understands
77 are meaningful here.
79 Returns the number of actions taken."
80 (let* ((actions 0)
81 user-keys mouse-event map prompt char elt tail def
82 ;; Non-nil means we should use mouse menus to ask.
83 use-menus
84 delayed-switch-frame
85 (next (if (or (and list (symbolp list))
86 (subrp list)
87 (byte-code-function-p list)
88 (and (consp list)
89 (eq (car list) 'lambda)))
90 (function (lambda ()
91 (setq elt (funcall list))))
92 (function (lambda ()
93 (if list
94 (progn
95 (setq elt (car list)
96 list (cdr list))
98 nil))))))
99 (if (and (listp last-nonmenu-event)
100 use-dialog-box)
101 ;; Make a list describing a dialog box.
102 (let ((object (if help (capitalize (nth 0 help))))
103 (objects (if help (capitalize (nth 1 help))))
104 (action (if help (capitalize (nth 2 help)))))
105 (setq map `(("Yes" . act) ("No" . skip) ("Quit" . exit)
106 (,(if help (concat action " " object " And Quit")
107 "Do it and Quit") . act-and-exit)
108 (,(if help (concat action " All " objects)
109 "Do All") . automatic)
110 ,@(mapcar (lambda (elt)
111 (cons (capitalize (nth 2 elt))
112 (vector (nth 1 elt))))
113 action-alist))
114 use-menus t
115 mouse-event last-nonmenu-event))
116 (setq user-keys (if action-alist
117 (concat (mapconcat (function
118 (lambda (elt)
119 (key-description
120 (char-to-string (car elt)))))
121 action-alist ", ")
122 " ")
124 ;; Make a map that defines each user key as a vector containing
125 ;; its definition.
126 map (cons 'keymap
127 (append (mapcar (lambda (elt)
128 (cons (car elt) (vector (nth 1 elt))))
129 action-alist)
130 query-replace-map))))
131 (unwind-protect
132 (progn
133 (if (stringp prompter)
134 (setq prompter `(lambda (object)
135 (format ,prompter object))))
136 (while (funcall next)
137 (setq prompt (funcall prompter elt))
138 (cond ((stringp prompt)
139 ;; Prompt the user about this object.
140 (setq quit-flag nil)
141 (if use-menus
142 (setq def (or (x-popup-dialog (or mouse-event use-menus)
143 (cons prompt map))
144 'quit))
145 ;; Prompt in the echo area.
146 (let ((cursor-in-echo-area (not no-cursor-in-echo-area))
147 (message-log-max nil))
148 (message "%s(y, n, !, ., q, %sor %s) "
149 prompt user-keys
150 (key-description (vector help-char)))
151 (if minibuffer-auto-raise
152 (raise-frame (window-frame (minibuffer-window))))
153 (while (progn
154 (setq char (read-event))
155 ;; If we get -1, from end of keyboard
156 ;; macro, try again.
157 (equal char -1)))
158 ;; Show the answer to the question.
159 (message "%s(y, n, !, ., q, %sor %s) %s"
160 prompt user-keys
161 (key-description (vector help-char))
162 (single-key-description char)))
163 (setq def (lookup-key map (vector char))))
164 (cond ((eq def 'exit)
165 (setq next (function (lambda () nil))))
166 ((eq def 'act)
167 ;; Act on the object.
168 (funcall actor elt)
169 (setq actions (1+ actions)))
170 ((eq def 'skip)
171 ;; Skip the object.
173 ((eq def 'act-and-exit)
174 ;; Act on the object and then exit.
175 (funcall actor elt)
176 (setq actions (1+ actions)
177 next (function (lambda () nil))))
178 ((or (eq def 'quit) (eq def 'exit-prefix))
179 (setq quit-flag t)
180 (setq next `(lambda ()
181 (setq next ',next)
182 ',elt)))
183 ((eq def 'automatic)
184 ;; Act on this and all following objects.
185 (if (funcall prompter elt)
186 (progn
187 (funcall actor elt)
188 (setq actions (1+ actions))))
189 (while (funcall next)
190 (if (funcall prompter elt)
191 (progn
192 (funcall actor elt)
193 (setq actions (1+ actions))))))
194 ((eq def 'help)
195 (with-output-to-temp-buffer "*Help*"
196 (princ
197 (let ((object (if help (nth 0 help) "object"))
198 (objects (if help (nth 1 help) "objects"))
199 (action (if help (nth 2 help) "act on")))
200 (concat
201 (format "Type SPC or `y' to %s the current %s;
202 DEL or `n' to skip the current %s;
203 RET or `q' to exit (skip all remaining %s);
204 ! to %s all remaining %s;
205 ESC or `q' to exit;\n"
206 action object object objects action
207 objects)
208 (mapconcat (function
209 (lambda (elt)
210 (format "%c to %s"
211 (nth 0 elt)
212 (nth 2 elt))))
213 action-alist
214 ";\n")
215 (if action-alist ";\n")
216 (format "or . (period) to %s \
217 the current %s and exit."
218 action object))))
219 (save-excursion
220 (set-buffer standard-output)
221 (help-mode)))
223 (setq next `(lambda ()
224 (setq next ',next)
225 ',elt)))
226 ((vectorp def)
227 ;; A user-defined key.
228 (if (funcall (aref def 0) elt) ;Call its function.
229 ;; The function has eaten this object.
230 (setq actions (1+ actions))
231 ;; Regurgitated; try again.
232 (setq next `(lambda ()
233 (setq next ',next)
234 ',elt))))
235 ((and (consp char)
236 (eq (car char) 'switch-frame))
237 ;; switch-frame event. Put it off until we're done.
238 (setq delayed-switch-frame char)
239 (setq next `(lambda ()
240 (setq next ',next)
241 ',elt)))
243 ;; Random char.
244 (message "Type %s for help."
245 (key-description (vector help-char)))
246 (beep)
247 (sit-for 1)
248 (setq next `(lambda ()
249 (setq next ',next)
250 ',elt)))))
251 (prompt
252 (funcall actor elt)
253 (setq actions (1+ actions))))))
254 (if delayed-switch-frame
255 (setq unread-command-events
256 (cons delayed-switch-frame unread-command-events))))
257 ;; Clear the last prompt from the minibuffer.
258 (let ((message-log-max nil))
259 (message ""))
260 ;; Return the number of actions that were taken.
261 actions))
263 ;;; map-ynp.el ends here