[bpt/emacs.git] / lisp / map-ynp.el

;;; map-ynp.el --- General-purpose boolean question-asker.

;; Copyright (C) 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.

;; Author: Roland McGrath <roland@gnu.ai.mit.edu>
;; Keywords: lisp, extensions

;; 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 2, 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; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.

;;; Commentary:

;; map-y-or-n-p is a general-purpose question-asking function.
;; It asks a series of y/n questions (a la y-or-n-p), and decides to
;; apply an action to each element of a list based on the answer.
;; The nice thing is that you also get some other possible answers
;; to use, reminiscent of query-replace: ! to answer y to all remaining
;; questions; ESC or q to answer n to all remaining questions; . to answer
;; y once and then n for the remainder; and you can get help with C-h.

;;; Code:

(defun map-y-or-n-p (prompter actor list &optional help action-alist
			      no-cursor-in-echo-area)
  "Ask a series of boolean questions.
Takes args PROMPTER ACTOR LIST, and optional args HELP and ACTION-ALIST.

LIST is a list of objects, or a function of no arguments to return the next
object or nil.

If PROMPTER is a string, the prompt is \(format PROMPTER OBJECT\).  If not
a string, PROMPTER is a function of one arg (an object from LIST), which
returns a string to be used as the prompt for that object.  If the return
value is not a string, it may be nil to ignore the object or non-nil to act
on the object without asking the user.

ACTOR is a function of one arg (an object from LIST),
which gets called with each object that the user answers `yes' for.

If HELP is given, it is a list (OBJECT OBJECTS ACTION),
where OBJECT is a string giving the singular noun for an elt of LIST;
OBJECTS is the plural noun for elts of LIST, and ACTION is a transitive
verb describing ACTOR.  The default is \(\"object\" \"objects\" \"act on\"\).

At the prompts, the user may enter y, Y, or SPC to act on that object;
n, N, or DEL to skip that object; ! to act on all following objects;
ESC or q to exit (skip all following objects); . (period) to act on the
current object and then exit; or \\[help-command] to get help.

If ACTION-ALIST is given, it is an alist (KEY FUNCTION HELP) of extra keys
that will be accepted.  KEY is a character; FUNCTION is a function of one
arg (an object from LIST); HELP is a string.  When the user hits KEY,
FUNCTION is called.  If it returns non-nil, the object is considered
\"acted upon\", and the next object from LIST is processed.  If it returns
nil, the prompt is repeated for the same object.

Final optional argument NO-CURSOR-IN-ECHO-AREA non-nil says not to set
`cursor-in-echo-area' while prompting.

This function uses `query-replace-map' to define the standard responses,
but not all of the responses which `query-replace' understands
are meaningful here.

Returns the number of actions taken."
  (let* ((actions 0)
	 user-keys mouse-event map prompt char elt tail def
	 ;; Non-nil means we should use mouse menus to ask.
	 use-menus
	 delayed-switch-frame
	 (next (if (or (and list (symbolp list))
		       (subrp list)
		       (byte-code-function-p list)
		       (and (consp list)
			    (eq (car list) 'lambda)))
		   (function (lambda ()
			       (setq elt (funcall list))))
		 (function (lambda ()
			     (if list
				 (progn
				   (setq elt (car list)
					 list (cdr list))
				   t)
			       nil))))))
    (if (listp last-nonmenu-event)
	;; Make a list describing a dialog box.
	(let ((object (capitalize (nth 0 help)))
	      (objects (capitalize (nth 1 help)))
	      (action (capitalize (nth 2 help))))
	  (setq map (` (("Yes" . act) ("No" . skip) ("Quit" . exit)
			((, (if help (concat action " " object " And Quit")
			      "Do it and Quit")) . act-and-exit)
			((, (if help (concat action " All " objects)
			      "Do All")) . automatic)
			(,@ (mapcar (lambda (elt)
				      (cons (capitalize (nth 2 elt))
					    (vector (nth 1 elt))))
				    action-alist))))
		use-menus t
		mouse-event last-nonmenu-event))			       
      (setq user-keys (if action-alist
			  (concat (mapconcat (function
					      (lambda (elt)
						(key-description
						 (char-to-string (car elt)))))
					     action-alist ", ")
				  " ")
			"")
	    ;; Make a map that defines each user key as a vector containing
	    ;; its definition.
	    map (cons 'keymap
		      (append (mapcar (lambda (elt)
					(cons (car elt) (vector (nth 1 elt))))
				      action-alist)
			      query-replace-map))))
    (unwind-protect
	(progn
	  (if (stringp prompter)
	      (setq prompter (` (lambda (object)
				  (format (, prompter) object)))))
	  (while (funcall next)
	    (setq prompt (funcall prompter elt))
	    (cond ((stringp prompt)
		   ;; Prompt the user about this object.
		   (setq quit-flag nil)
		   (if use-menus
		       (setq def (or (x-popup-dialog (or mouse-event use-menus)
						     (cons prompt map))
				     'quit))
		     ;; Prompt in the echo area.
		     (let ((cursor-in-echo-area (not no-cursor-in-echo-area))
			   (message-log-max nil))
		       (message "%s(y, n, !, ., q, %sor %s) "
				prompt user-keys
				(key-description (vector help-char)))
		       (if minibuffer-auto-raise
			   (raise-frame (window-frame (minibuffer-window))))
		       (setq char (read-event))
		       ;; Show the answer to the question.
		       (message "%s(y, n, !, ., q, %sor %s) %s"
				prompt user-keys
				(key-description (vector help-char))
				(single-key-description char)))
		     (setq def (lookup-key map (vector char))))
		   (cond ((eq def 'exit)
			  (setq next (function (lambda () nil))))
			 ((eq def 'act)
			  ;; Act on the object.
			  (funcall actor elt)
			  (setq actions (1+ actions)))
			 ((eq def 'skip)
			  ;; Skip the object.
			  )
			 ((eq def 'act-and-exit)
			  ;; Act on the object and then exit.
			  (funcall actor elt)
			  (setq actions (1+ actions)
				next (function (lambda () nil))))
			 ((or (eq def 'quit) (eq def 'exit-prefix))
			  (setq quit-flag t)
			  (setq next (` (lambda ()
					  (setq next '(, next))
					  '(, elt)))))
			 ((eq def 'automatic)
			  ;; Act on this and all following objects.
			  (if (funcall prompter elt)
			      (progn
				(funcall actor elt)
				(setq actions (1+ actions))))
			  (while (funcall next)
			    (if (funcall prompter elt)
				(progn
				  (funcall actor elt)
				  (setq actions (1+ actions))))))
			 ((eq def 'help)
			  (with-output-to-temp-buffer "*Help*"
			    (princ
			     (let ((object (if help (nth 0 help) "object"))
				   (objects (if help (nth 1 help) "objects"))
				   (action (if help (nth 2 help) "act on")))
			       (concat
				(format "Type SPC or `y' to %s the current %s;
DEL or `n' to skip the current %s;
! to %s all remaining %s;
ESC or `q' to exit;\n"
					action object object action objects)
				(mapconcat (function
					    (lambda (elt)
					      (format "%c to %s"
						      (nth 0 elt)
						      (nth 2 elt))))
					   action-alist
					   ";\n")
				(if action-alist ";\n")
				(format "or . (period) to %s \
the current %s and exit."
					action object))))
			    (save-excursion
			      (set-buffer standard-output)
			      (help-mode)))

			  (setq next (` (lambda ()
					  (setq next '(, next))
					  '(, elt)))))
			 ((vectorp def)
			  ;; A user-defined key.
			  (if (funcall (aref def 0) elt) ;Call its function.
			      ;; The function has eaten this object.
			      (setq actions (1+ actions))
			    ;; Regurgitated; try again.
			    (setq next (` (lambda ()
					    (setq next '(, next))
					    '(, elt))))))
			 ((and (consp char)
			       (eq (car char) 'switch-frame))
			  ;; switch-frame event.  Put it off until we're done.
			  (setq delayed-switch-frame char)
			  (setq next (` (lambda ()
					  (setq next '(, next))
					  '(, elt)))))
			 (t
			  ;; Random char.
			  (message "Type %s for help."
				   (key-description (vector help-char)))
			  (beep)
			  (sit-for 1)
			  (setq next (` (lambda ()
					  (setq next '(, next))
					  '(, elt)))))))
		  (prompt
		   (funcall actor elt)
		   (setq actions (1+ actions))))))
      (if delayed-switch-frame
	  (setq unread-command-events
		(cons delayed-switch-frame unread-command-events))))
    ;; Clear the last prompt from the minibuffer.
    (let ((message-log-max nil))
      (message ""))
    ;; Return the number of actions that were taken.
    actions))

;;; map-ynp.el ends here
Commit	Line	Data
6594deb0 ER	1	;;; map-ynp.el --- General-purpose boolean question-asker.
6594deb0 ER	2
b578f267	3	;; Copyright (C) 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
eea8d4ef	4
e5167999	5	;; Author: Roland McGrath <roland@gnu.ai.mit.edu>
fd7fa35a	6	;; Keywords: lisp, extensions
e5167999	7
b578f267 EN	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.
e5167999 ER	24
	25	;;; Commentary:
	26
b578f267 EN	27	;; map-y-or-n-p is a general-purpose question-asking function.
b578f267 EN	28	;; It asks a series of y/n questions (a la y-or-n-p), and decides to
68e3e5f5	29	;; apply an action to each element of a list based on the answer.
b578f267 EN	30	;; The nice thing is that you also get some other possible answers
	31	;; to use, reminiscent of query-replace: ! to answer y to all remaining
	32	;; questions; ESC or q to answer n to all remaining questions; . to answer
	33	;; y once and then n for the remainder; and you can get help with C-h.
60205e0b	34
e5167999 ER	35	;;; Code:
e5167999 ER	36
fd95709e RM	37	(defun map-y-or-n-p (prompter actor list &optional help action-alist
fd95709e RM	38	no-cursor-in-echo-area)
60205e0b	39	"Ask a series of boolean questions.
907482b9	40	Takes args PROMPTER ACTOR LIST, and optional args HELP and ACTION-ALIST.
60205e0b RM	41
	42	LIST is a list of objects, or a function of no arguments to return the next
	43	object or nil.
	44
9fd54390	45	If PROMPTER is a string, the prompt is \(format PROMPTER OBJECT\). If not
03759fe0 RM	46	a string, PROMPTER is a function of one arg (an object from LIST), which
03759fe0 RM	47	returns a string to be used as the prompt for that object. If the return
933fb957 RM	48	value is not a string, it may be nil to ignore the object or non-nil to act
933fb957 RM	49	on the object without asking the user.
03759fe0	50
60205e0b RM	51	ACTOR is a function of one arg (an object from LIST),
	52	which gets called with each object that the user answers `yes' for.
	53
	54	If HELP is given, it is a list (OBJECT OBJECTS ACTION),
	55	where OBJECT is a string giving the singular noun for an elt of LIST;
	56	OBJECTS is the plural noun for elts of LIST, and ACTION is a transitive
	57	verb describing ACTOR. The default is \(\"object\" \"objects\" \"act on\"\).
	58
	59	At the prompts, the user may enter y, Y, or SPC to act on that object;
	60	n, N, or DEL to skip that object; ! to act on all following objects;
	61	ESC or q to exit (skip all following objects); . (period) to act on the
	62	current object and then exit; or \\[help-command] to get help.
	63
907482b9 RM	64	If ACTION-ALIST is given, it is an alist (KEY FUNCTION HELP) of extra keys
	65	that will be accepted. KEY is a character; FUNCTION is a function of one
	66	arg (an object from LIST); HELP is a string. When the user hits KEY,
	67	FUNCTION is called. If it returns non-nil, the object is considered
	68	\"acted upon\", and the next object from LIST is processed. If it returns
	69	nil, the prompt is repeated for the same object.
	70
fd95709e RM	71	Final optional argument NO-CURSOR-IN-ECHO-AREA non-nil says not to set
	72	`cursor-in-echo-area' while prompting.
	73
0a2eb25e RS	74	This function uses `query-replace-map' to define the standard responses,
	75	but not all of the responses which `query-replace' understands
	76	are meaningful here.
	77
60205e0b	78	Returns the number of actions taken."
c5068ec5 RM	79	(let* ((actions 0)
c5068ec5 RM	80	user-keys mouse-event map prompt char elt tail def
5233c7f5 RS	81	;; Non-nil means we should use mouse menus to ask.
5233c7f5 RS	82	use-menus
c5068ec5	83	delayed-switch-frame
fba98516	84	(next (if (or (and list (symbolp list))
aa228418	85	(subrp list)
dbc4e1c1	86	(byte-code-function-p list)
aa228418 JB	87	(and (consp list)
	88	(eq (car list) 'lambda)))
	89	(function (lambda ()
	90	(setq elt (funcall list))))
	91	(function (lambda ()
	92	(if list
	93	(progn
	94	(setq elt (car list)
	95	list (cdr list))
	96	t)
	97	nil))))))
c5068ec5 RM	98	(if (listp last-nonmenu-event)
	99	;; Make a list describing a dialog box.
	100	(let ((object (capitalize (nth 0 help)))
	101	(objects (capitalize (nth 1 help)))
	102	(action (capitalize (nth 2 help))))
	103	(setq map (` (("Yes" . act) ("No" . skip) ("Quit" . exit)
	104	((, (if help (concat action " " object " And Quit")
	105	"Do it and Quit")) . act-and-exit)
	106	((, (if help (concat action " All " objects)
	107	"Do All")) . automatic)
	108	(,@ (mapcar (lambda (elt)
230ac7f6	109	(cons (capitalize (nth 2 elt))
c5068ec5 RM	110	(vector (nth 1 elt))))
c5068ec5 RM	111	action-alist))))
5233c7f5	112	use-menus t
c5068ec5 RM	113	mouse-event last-nonmenu-event))
	114	(setq user-keys (if action-alist
	115	(concat (mapconcat (function
	116	(lambda (elt)
	117	(key-description
	118	(char-to-string (car elt)))))
	119	action-alist ", ")
	120	" ")
	121	"")
	122	;; Make a map that defines each user key as a vector containing
	123	;; its definition.
	124	map (cons 'keymap
	125	(append (mapcar (lambda (elt)
	126	(cons (car elt) (vector (nth 1 elt))))
	127	action-alist)
	128	query-replace-map))))
3eea8aa2 JB	129	(unwind-protect
	130	(progn
	131	(if (stringp prompter)
	132	(setq prompter (` (lambda (object)
	133	(format (, prompter) object)))))
	134	(while (funcall next)
	135	(setq prompt (funcall prompter elt))
933fb957 RM	136	(cond ((stringp prompt)
	137	;; Prompt the user about this object.
	138	(setq quit-flag nil)
5233c7f5 RS	139	(if use-menus
5233c7f5 RS	140	(setq def (or (x-popup-dialog (or mouse-event use-menus)
933fb957 RM	141	(cons prompt map))
	142	'quit))
	143	;; Prompt in the echo area.
	144	(let ((cursor-in-echo-area (not no-cursor-in-echo-area))
	145	(message-log-max nil))
	146	(message "%s(y, n, !, ., q, %sor %s) "
	147	prompt user-keys
	148	(key-description (vector help-char)))
55b4b20a RS	149	(if minibuffer-auto-raise
55b4b20a RS	150	(raise-frame (window-frame (minibuffer-window))))
933fb957 RM	151	(setq char (read-event))
	152	;; Show the answer to the question.
	153	(message "%s(y, n, !, ., q, %sor %s) %s"
	154	prompt user-keys
	155	(key-description (vector help-char))
	156	(single-key-description char)))
	157	(setq def (lookup-key map (vector char))))
	158	(cond ((eq def 'exit)
	159	(setq next (function (lambda () nil))))
	160	((eq def 'act)
	161	;; Act on the object.
	162	(funcall actor elt)
	163	(setq actions (1+ actions)))
	164	((eq def 'skip)
	165	;; Skip the object.
	166	)
	167	((eq def 'act-and-exit)
	168	;; Act on the object and then exit.
	169	(funcall actor elt)
	170	(setq actions (1+ actions)
	171	next (function (lambda () nil))))
	172	((or (eq def 'quit) (eq def 'exit-prefix))
	173	(setq quit-flag t)
	174	(setq next (` (lambda ()
	175	(setq next '(, next))
	176	'(, elt)))))
	177	((eq def 'automatic)
	178	;; Act on this and all following objects.
	179	(if (funcall prompter elt)
	180	(progn
	181	(funcall actor elt)
	182	(setq actions (1+ actions))))
	183	(while (funcall next)
	184	(if (funcall prompter elt)
	185	(progn
	186	(funcall actor elt)
	187	(setq actions (1+ actions))))))
	188	((eq def 'help)
	189	(with-output-to-temp-buffer "Help"
	190	(princ
	191	(let ((object (if help (nth 0 help) "object"))
	192	(objects (if help (nth 1 help) "objects"))
	193	(action (if help (nth 2 help) "act on")))
	194	(concat
	195	(format "Type SPC or `y' to %s the current %s;
0a2eb25e RS	196	DEL or `n' to skip the current %s;
	197	! to %s all remaining %s;
	198	ESC or `q' to exit;\n"
933fb957 RM	199	action object object action objects)
	200	(mapconcat (function
	201	(lambda (elt)
	202	(format "%c to %s"
	203	(nth 0 elt)
	204	(nth 2 elt))))
	205	action-alist
	206	";\n")
	207	(if action-alist ";\n")
	208	(format "or . (period) to %s \
0a2eb25e	209	the current %s and exit."
933fb957 RM	210	action object))))
	211	(save-excursion
	212	(set-buffer standard-output)
	213	(help-mode)))
	214
	215	(setq next (` (lambda ()
	216	(setq next '(, next))
	217	'(, elt)))))
	218	((vectorp def)
	219	;; A user-defined key.
	220	(if (funcall (aref def 0) elt) ;Call its function.
	221	;; The function has eaten this object.
	222	(setq actions (1+ actions))
	223	;; Regurgitated; try again.
	224	(setq next (` (lambda ()
	225	(setq next '(, next))
	226	'(, elt))))))
	227	((and (consp char)
	228	(eq (car char) 'switch-frame))
	229	;; switch-frame event. Put it off until we're done.
	230	(setq delayed-switch-frame char)
	231	(setq next (` (lambda ()
	232	(setq next '(, next))
	233	'(, elt)))))
	234	(t
	235	;; Random char.
	236	(message "Type %s for help."
	237	(key-description (vector help-char)))
	238	(beep)
	239	(sit-for 1)
	240	(setq next (` (lambda ()
	241	(setq next '(, next))
	242	'(, elt)))))))
	243	(prompt
	244	(funcall actor elt)
	245	(setq actions (1+ actions))))))
3eea8aa2 JB	246	(if delayed-switch-frame
	247	(setq unread-command-events
	248	(cons delayed-switch-frame unread-command-events))))
60205e0b	249	;; Clear the last prompt from the minibuffer.
a66839ce KH	250	(let ((message-log-max nil))
a66839ce KH	251	(message ""))
60205e0b RM	252	;; Return the number of actions that were taken.
60205e0b RM	253	actions))
6594deb0 ER	254
6594deb0 ER	255	;;; map-ynp.el ends here