[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
;; applies 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:

;;;###autoload
(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
	 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))))
		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 mouse-event
		       (setq def (or (x-popup-dialog mouse-event
						     (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)))
		       (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.
	28	;; It asks a series of y/n questions (a la y-or-n-p), and decides to
	29	;; applies an action to each element of a list based on the answer.
	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
60205e0b	37	;;;###autoload
fd95709e RM	38	(defun map-y-or-n-p (prompter actor list &optional help action-alist
fd95709e RM	39	no-cursor-in-echo-area)
60205e0b	40	"Ask a series of boolean questions.
907482b9	41	Takes args PROMPTER ACTOR LIST, and optional args HELP and ACTION-ALIST.
60205e0b RM	42
	43	LIST is a list of objects, or a function of no arguments to return the next
	44	object or nil.
	45
9fd54390	46	If PROMPTER is a string, the prompt is \(format PROMPTER OBJECT\). If not
03759fe0 RM	47	a string, PROMPTER is a function of one arg (an object from LIST), which
03759fe0 RM	48	returns a string to be used as the prompt for that object. If the return
933fb957 RM	49	value is not a string, it may be nil to ignore the object or non-nil to act
933fb957 RM	50	on the object without asking the user.
03759fe0	51
60205e0b RM	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.
	54
	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 \(\"object\" \"objects\" \"act on\"\).
	59
	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.
	64
907482b9 RM	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.
	71
fd95709e RM	72	Final optional argument NO-CURSOR-IN-ECHO-AREA non-nil says not to set
	73	`cursor-in-echo-area' while prompting.
	74
0a2eb25e RS	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.
	78
60205e0b	79	Returns the number of actions taken."
c5068ec5 RM	80	(let* ((actions 0)
	81	user-keys mouse-event map prompt char elt tail def
	82	delayed-switch-frame
fba98516	83	(next (if (or (and list (symbolp list))
aa228418	84	(subrp list)
dbc4e1c1	85	(byte-code-function-p list)
aa228418 JB	86	(and (consp list)
	87	(eq (car list) 'lambda)))
	88	(function (lambda ()
	89	(setq elt (funcall list))))
	90	(function (lambda ()
	91	(if list
	92	(progn
	93	(setq elt (car list)
	94	list (cdr list))
	95	t)
	96	nil))))))
c5068ec5 RM	97	(if (listp last-nonmenu-event)
	98	;; Make a list describing a dialog box.
	99	(let ((object (capitalize (nth 0 help)))
	100	(objects (capitalize (nth 1 help)))
	101	(action (capitalize (nth 2 help))))
	102	(setq map (` (("Yes" . act) ("No" . skip) ("Quit" . exit)
	103	((, (if help (concat action " " object " And Quit")
	104	"Do it and Quit")) . act-and-exit)
	105	((, (if help (concat action " All " objects)
	106	"Do All")) . automatic)
	107	(,@ (mapcar (lambda (elt)
230ac7f6	108	(cons (capitalize (nth 2 elt))
c5068ec5 RM	109	(vector (nth 1 elt))))
	110	action-alist))))
	111	mouse-event last-nonmenu-event))
	112	(setq user-keys (if action-alist
	113	(concat (mapconcat (function
	114	(lambda (elt)
	115	(key-description
	116	(char-to-string (car elt)))))
	117	action-alist ", ")
	118	" ")
	119	"")
	120	;; Make a map that defines each user key as a vector containing
	121	;; its definition.
	122	map (cons 'keymap
	123	(append (mapcar (lambda (elt)
	124	(cons (car elt) (vector (nth 1 elt))))
	125	action-alist)
	126	query-replace-map))))
3eea8aa2 JB	127	(unwind-protect
	128	(progn
	129	(if (stringp prompter)
	130	(setq prompter (` (lambda (object)
	131	(format (, prompter) object)))))
	132	(while (funcall next)
	133	(setq prompt (funcall prompter elt))
933fb957 RM	134	(cond ((stringp prompt)
	135	;; Prompt the user about this object.
	136	(setq quit-flag nil)
	137	(if mouse-event
	138	(setq def (or (x-popup-dialog mouse-event
	139	(cons prompt map))
	140	'quit))
	141	;; Prompt in the echo area.
	142	(let ((cursor-in-echo-area (not no-cursor-in-echo-area))
	143	(message-log-max nil))
	144	(message "%s(y, n, !, ., q, %sor %s) "
	145	prompt user-keys
	146	(key-description (vector help-char)))
	147	(setq char (read-event))
	148	;; Show the answer to the question.
	149	(message "%s(y, n, !, ., q, %sor %s) %s"
	150	prompt user-keys
	151	(key-description (vector help-char))
	152	(single-key-description char)))
	153	(setq def (lookup-key map (vector char))))
	154	(cond ((eq def 'exit)
	155	(setq next (function (lambda () nil))))
	156	((eq def 'act)
	157	;; Act on the object.
	158	(funcall actor elt)
	159	(setq actions (1+ actions)))
	160	((eq def 'skip)
	161	;; Skip the object.
	162	)
	163	((eq def 'act-and-exit)
	164	;; Act on the object and then exit.
	165	(funcall actor elt)
	166	(setq actions (1+ actions)
	167	next (function (lambda () nil))))
	168	((or (eq def 'quit) (eq def 'exit-prefix))
	169	(setq quit-flag t)
	170	(setq next (` (lambda ()
	171	(setq next '(, next))
	172	'(, elt)))))
	173	((eq def 'automatic)
	174	;; Act on this and all following objects.
	175	(if (funcall prompter elt)
	176	(progn
	177	(funcall actor elt)
	178	(setq actions (1+ actions))))
	179	(while (funcall next)
	180	(if (funcall prompter elt)
	181	(progn
	182	(funcall actor elt)
	183	(setq actions (1+ actions))))))
	184	((eq def 'help)
	185	(with-output-to-temp-buffer "Help"
	186	(princ
	187	(let ((object (if help (nth 0 help) "object"))
	188	(objects (if help (nth 1 help) "objects"))
	189	(action (if help (nth 2 help) "act on")))
	190	(concat
	191	(format "Type SPC or `y' to %s the current %s;
0a2eb25e RS	192	DEL or `n' to skip the current %s;
	193	! to %s all remaining %s;
	194	ESC or `q' to exit;\n"
933fb957 RM	195	action object object action objects)
	196	(mapconcat (function
	197	(lambda (elt)
	198	(format "%c to %s"
	199	(nth 0 elt)
	200	(nth 2 elt))))
	201	action-alist
	202	";\n")
	203	(if action-alist ";\n")
	204	(format "or . (period) to %s \
0a2eb25e	205	the current %s and exit."
933fb957 RM	206	action object))))
	207	(save-excursion
	208	(set-buffer standard-output)
	209	(help-mode)))
	210
	211	(setq next (` (lambda ()
	212	(setq next '(, next))
	213	'(, elt)))))
	214	((vectorp def)
	215	;; A user-defined key.
	216	(if (funcall (aref def 0) elt) ;Call its function.
	217	;; The function has eaten this object.
	218	(setq actions (1+ actions))
	219	;; Regurgitated; try again.
	220	(setq next (` (lambda ()
	221	(setq next '(, next))
	222	'(, elt))))))
	223	((and (consp char)
	224	(eq (car char) 'switch-frame))
	225	;; switch-frame event. Put it off until we're done.
	226	(setq delayed-switch-frame char)
	227	(setq next (` (lambda ()
	228	(setq next '(, next))
	229	'(, elt)))))
	230	(t
	231	;; Random char.
	232	(message "Type %s for help."
	233	(key-description (vector help-char)))
	234	(beep)
	235	(sit-for 1)
	236	(setq next (` (lambda ()
	237	(setq next '(, next))
	238	'(, elt)))))))
	239	(prompt
	240	(funcall actor elt)
	241	(setq actions (1+ actions))))))
3eea8aa2 JB	242	(if delayed-switch-frame
	243	(setq unread-command-events
	244	(cons delayed-switch-frame unread-command-events))))
60205e0b	245	;; Clear the last prompt from the minibuffer.
a66839ce KH	246	(let ((message-log-max nil))
a66839ce KH	247	(message ""))
60205e0b RM	248	;; Return the number of actions that were taken.
60205e0b RM	249	actions))
6594deb0 ER	250
6594deb0 ER	251	;;; map-ynp.el ends here