1 ;;; help.el --- help commands for Emacs
3 ;; Copyright (C) 1985, 1986, 1993, 1994, 1998, 1999, 2000, 2001, 2002,
4 ;; 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
7 ;; Keywords: help, internal
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)
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., 51 Franklin Street, Fifth Floor,
24 ;; Boston, MA 02110-1301, USA.
28 ;; This code implements GNU Emacs' on-line help system, the one invoked by
29 ;; `M-x help-for-help'.
33 ;; Get the macro make-help-screen when this is compiled,
34 ;; or run interpreted, but not when the compiled code is loaded.
35 (eval-when-compile (require 'help-macro
))
37 ;; This makes `with-output-to-temp-buffer' buffers use `help-mode'.
38 (add-hook 'temp-buffer-setup-hook
'help-mode-setup
)
39 (add-hook 'temp-buffer-show-hook
'help-mode-finish
)
42 (let ((map (make-sparse-keymap)))
43 (define-key map
(char-to-string help-char
) 'help-for-help
)
44 (define-key map
[help] 'help-for-help)
45 (define-key map [f1] 'help-for-help)
46 (define-key map "." 'display-local-help)
47 (define-key map "?" 'help-for-help)
49 (define-key map "\C-c" 'describe-copying)
50 (define-key map "\C-d" 'describe-distribution)
51 (define-key map "\C-e" 'view-emacs-problems)
52 (define-key map "\C-f" 'view-emacs-FAQ)
53 (define-key map "\C-m" 'view-order-manuals)
54 (define-key map "\C-n" 'view-emacs-news)
55 (define-key map "\C-p" 'describe-project)
56 (define-key map "\C-t" 'view-todo)
57 (define-key map "\C-w" 'describe-no-warranty)
59 ;; This does not fit the pattern, but it is natural given the C-\ command.
60 (define-key map "\C-\\" 'describe-input-method)
62 (define-key map "C" 'describe-coding-system)
63 (define-key map "F" 'Info-goto-emacs-command-node)
64 (define-key map "I" 'describe-input-method)
65 (define-key map "K" 'Info-goto-emacs-key-command-node)
66 (define-key map "L" 'describe-language-environment)
67 (define-key map "S" 'info-lookup-symbol)
69 (define-key map "a" 'apropos-command)
70 (define-key map "b" 'describe-bindings)
71 (define-key map "c" 'describe-key-briefly)
72 (define-key map "d" 'apropos-documentation)
73 (define-key map "e" 'view-echo-area-messages)
74 (define-key map "f" 'describe-function)
75 (define-key map "h" 'view-hello-file)
77 (define-key map "i" 'info)
78 (define-key map "4i" 'info-other-window)
80 (define-key map "k" 'describe-key)
81 (define-key map "l" 'view-lossage)
82 (define-key map "m" 'describe-mode)
83 (define-key map "n" 'view-emacs-news)
84 (define-key map "p" 'finder-by-keyword)
85 (define-key map "r" 'info-emacs-manual)
86 (define-key map "s" 'describe-syntax)
87 (define-key map "t" 'help-with-tutorial)
88 (define-key map "w" 'where-is)
89 (define-key map "v" 'describe-variable)
90 (define-key map "q" 'help-quit)
92 "Keymap for characters following the Help key.")
94 (define-key global-map (char-to-string help-char) 'help-command)
95 (define-key global-map [help] 'help-command
)
96 (define-key global-map
[f1] 'help-command)
97 (fset 'help-command help-map)
99 (autoload 'finder-by-keyword "finder"
100 "Find packages matching a given keyword." t)
102 ;; insert-button makes the action nil if it is not store somewhere
103 (defvar help-button-cache nil)
107 "Just exit from the Help command's command loop."
111 (defvar help-return-method nil
112 "What to do to \"exit\" the help buffer.
114 (WINDOW . t) delete the selected window (and possibly its frame,
115 see `quit-window' and `View-quit'), go to WINDOW.
116 (WINDOW . quit-window) do quit-window, then select WINDOW.
117 (WINDOW BUF START POINT) display BUF at START, POINT, then select WINDOW.")
119 (defun print-help-return-message (&optional function)
120 "Display or return message saying how to restore windows after help command.
121 This function assumes that `standard-output' is the help buffer.
122 It computes a message, and applies the optional argument FUNCTION to it.
123 If FUNCTION is nil, it applies `message', thus displaying the message.
124 In addition, this function sets up `help-return-method', which see, that
125 specifies what to do when the user exits the help buffer."
126 (and (not (get-buffer-window standard-output))
130 (special-display-p (buffer-name standard-output)))
131 (setq help-return-method (cons (selected-window) t))
132 ;; If the help output buffer is a special display buffer,
133 ;; don't say anything about how to get rid of it.
134 ;; First of all, the user will do that with the window
135 ;; manager, not with Emacs.
136 ;; Secondly, the buffer has not been displayed yet,
137 ;; so we don't know whether its frame will be selected.
139 (display-buffer-reuse-frames
140 (setq help-return-method (cons (selected-window)
143 ((not (one-window-p t))
144 (setq help-return-method
145 (cons (selected-window) 'quit-window))
146 "Type \\[switch-to-buffer-other-window] RET to restore the other window.")
148 (setq help-return-method (cons (selected-window) t))
149 "Type \\[delete-other-windows] to remove help window.")
151 (setq help-return-method
152 (list (selected-window) (window-buffer)
153 (window-start) (window-point)))
154 "Type \\[switch-to-buffer] RET to remove help window."))))
155 (funcall (or function 'message)
158 (substitute-command-keys first-message))
159 (if first-message " ")
160 ;; If the help buffer will go in a separate frame,
161 ;; it's no use mentioning a command to scroll, so don't.
162 (if (or pop-up-windows
163 (special-display-p (buffer-name standard-output)))
165 (if (same-window-p (buffer-name standard-output))
166 ;; Say how to scroll this window.
167 (substitute-command-keys
168 "\\[scroll-up] to scroll the help.")
169 ;; Say how to scroll some other window.
170 (substitute-command-keys
171 "\\[scroll-other-window] to scroll the help."))))))))
173 ;; So keyboard macro definitions are documented correctly
174 (fset 'defining-kbd-macro (symbol-function 'start-kbd-macro))
176 (defalias 'help 'help-for-help-internal)
177 ;; find-function can find this.
178 (defalias 'help-for-help 'help-for-help-internal)
179 ;; It can't find this, but nobody will look.
180 (make-help-screen help-for-help-internal
181 "a b c C e f F i I k C-k l L m p r s t v w C-c C-d C-f C-n C-p C-t C-w . or ? :"
182 "You have typed %THIS-KEY%, the help character. Type a Help option:
183 \(Use SPC or DEL to scroll through this text. Type \\<help-map>\\[help-quit] to exit the Help command.)
185 a command-apropos. Give a list of words or a regexp, to get a list of
186 commands whose names match. See also the apropos command.
187 b describe-bindings. Display table of all key bindings.
188 c describe-key-briefly. Type a command key sequence;
189 it prints the function name that sequence runs.
190 C describe-coding-system. This describes either a specific coding system
191 (if you type its name) or the coding systems currently in use
192 (if you type just RET).
193 d apropos-documentation. Give a pattern (a list or words or a regexp), and
194 see a list of functions, variables, and other items whose built-in
195 doucmentation string matches that pattern. See also the apropos command.
196 e view-echo-area-messages. Show the buffer where the echo-area messages
198 f describe-function. Type a function name and get its documentation.
199 F Info-goto-emacs-command-node. Type a function name;
200 it takes you to the on-line manual's section that describes
202 h Display the HELLO file which illustrates various scripts.
203 i info. The Info documentation reader: read on-line manuals.
204 I describe-input-method. Describe a specific input method (if you type
205 its name) or the current input method (if you type just RET).
206 k describe-key. Type a command key sequence;
207 it displays the full documentation for that key sequence.
208 K Info-goto-emacs-key-command-node. Type a command key sequence;
209 it takes you to the on-line manual's section that describes
210 the command bound to that key.
211 l view-lossage. Show last 100 characters you typed.
212 L describe-language-environment. This describes either a
213 specific language environment (if you type its name)
214 or the current language environment (if you type just RET).
215 m describe-mode. Display documentation of current minor modes,
216 and the current major mode, including their special commands.
217 n view-emacs-news. Display news of recent Emacs changes.
218 p finder-by-keyword. Find packages matching a given topic keyword.
219 r info-emacs-manual. Display the Emacs manual in Info mode.
220 s describe-syntax. Display contents of syntax table, plus explanations.
221 S info-lookup-symbol. Display the definition of a specific symbol
222 as found in the manual for the language this buffer is written in.
223 t help-with-tutorial. Select the Emacs learn-by-doing tutorial.
224 v describe-variable. Type name of a variable;
225 it displays the variable's documentation and value.
226 w where-is. Type command name; it prints which keystrokes
228 . display-local-help. Display any available local help at point
231 C-c Display Emacs copying permission (GNU General Public License).
232 C-d Display Emacs ordering information.
233 C-e Display info about Emacs problems.
234 C-f Display the Emacs FAQ.
235 C-m Display how to order printed Emacs manuals.
236 C-n Display news of recent Emacs changes.
237 C-p Display information about the GNU project.
238 C-t Display the Emacs TODO list.
239 C-w Display information on absence of warranty for GNU Emacs."
244 (defun function-called-at-point ()
245 "Return a function around point or else called by the list containing point.
246 If that doesn't give a function, return nil."
247 (or (with-syntax-table emacs-lisp-mode-syntax-table
248 (or (condition-case ()
250 (or (not (zerop (skip-syntax-backward "_w")))
251 (eq (char-syntax (following-char)) ?w)
252 (eq (char-syntax (following-char)) ?_)
254 (skip-chars-forward "'")
255 (let ((obj (read (current-buffer))))
256 (and (symbolp obj) (fboundp obj) obj)))
261 (narrow-to-region (max (point-min)
262 (- (point) 1000)) (point-max))
263 ;; Move up to surrounding paren, then after the open.
266 ;; If there is space here, this is probably something
267 ;; other than a real Lisp function call, so ignore it.
268 (if (looking-at "[ \t]")
269 (error "Probably not a Lisp function call"))
270 (let ((obj (read (current-buffer))))
271 (and (symbolp obj) (fboundp obj) obj))))
273 (let* ((str (find-tag-default))
274 (sym (if str (intern-soft str))))
275 (if (and sym (fboundp sym))
278 (when (and str (string-match "\\`\\W*\\(.*?\\)\\W*\\'" str))
279 (setq sym (intern-soft (match-string 1 str)))
280 (and (fboundp sym) sym)))))))
283 ;;; `User' help functions
285 (defun describe-distribution ()
286 "Display info on how to obtain the latest version of GNU Emacs."
288 (view-file (expand-file-name "DISTRIB" data-directory)))
290 (defun describe-copying ()
291 "Display info on how you may redistribute copies of GNU Emacs."
293 (view-file (expand-file-name "COPYING" data-directory))
294 (goto-char (point-min)))
296 (defun describe-project ()
297 "Display info on the GNU project."
299 (view-file (expand-file-name "THE-GNU-PROJECT" data-directory))
300 (goto-char (point-min)))
302 (defun describe-no-warranty ()
303 "Display info on all the kinds of warranty Emacs does NOT have."
306 (let (case-fold-search)
307 (search-forward "NO WARRANTY")
310 (defun describe-prefix-bindings ()
311 "Describe the bindings of the prefix used to reach this command.
312 The prefix described consists of all but the last event
313 of the key sequence that ran this command."
315 (let* ((key (this-command-keys)))
318 (substring key 0 (1- (length key)))
319 (let ((prefix (make-vector (1- (length key)) nil))
321 (while (< i (length prefix))
322 (aset prefix i (aref key i))
325 ;; Make C-h after a prefix, when not specifically bound,
326 ;; run describe-prefix-bindings.
327 (setq prefix-help-command 'describe-prefix-bindings)
329 (defun view-emacs-news (&optional arg)
330 "Display info on recent changes to Emacs.
331 With argument, display info only for the selected version."
334 (view-file (expand-file-name "NEWS" data-directory))
342 (insert-file-contents
343 (expand-file-name file data-directory))
345 (while (re-search-forward
346 (if (string-match "^ONEWS\\.[0-9]+$" file)
347 "Changes in \\(?:Emacs\\|version\\)?[ \t]*\\([0-9]+\\(?:\\.[0-9]+\\)?\\)"
348 "^\* [^0-9\n]*\\([0-9]+\\.[0-9]+\\)") nil t)
349 (setq res (cons (list (match-string-no-properties 1)
352 (append '("NEWS" "ONEWS")
353 (directory-files data-directory nil
354 "^ONEWS\\.[0-9]+$" nil)))))
356 (string< (car b) (car a)))))
358 (version (completing-read
359 (format "Read NEWS for the version (default %s): " current)
360 (mapcar 'car map) nil nil nil nil current))
361 (file (cadr (assoc version map)))
364 (error "No news is good news")
365 (view-file (expand-file-name file data-directory))
367 (goto-char (point-min))
368 (when (re-search-forward
369 (concat (if (string-match "^ONEWS\\.[0-9]+$" file)
370 "Changes in \\(?:Emacs\\|version\\)?[ \t]*"
371 "^\* [^0-9\n]*") version)
377 (while (and (setq res
379 (if (string-match "^ONEWS\\.[0-9]+$" file)
380 "Changes in \\(?:Emacs\\|version\\)?[ \t]*\\([0-9]+\\(?:\\.[0-9]+\\)?\\)"
381 "^\* [^0-9\n]*\\([0-9]+\\.[0-9]+\\)") nil t))
382 (equal (match-string-no-properties 1) version)))
383 (or res (goto-char (point-max)))
387 (defun view-todo (&optional arg)
388 "Display the Emacs TODO list."
390 (view-file (expand-file-name "TODO" data-directory)))
392 (defun view-echo-area-messages ()
393 "View the log of recent echo-area messages: the `*Messages*' buffer.
394 The number of messages retained in that buffer
395 is specified by the variable `message-log-max'."
397 (switch-to-buffer (get-buffer-create "*Messages*")))
399 (defun view-order-manuals ()
400 "Display the Emacs ORDERS file."
402 (view-file (expand-file-name "ORDERS" data-directory))
405 (defun view-emacs-FAQ ()
406 "Display the Emacs Frequently Asked Questions (FAQ) file."
408 ;; (find-file-read-only (expand-file-name "FAQ" data-directory))
411 (defun view-emacs-problems ()
412 "Display info on known problems with Emacs and possible workarounds."
414 (view-file (expand-file-name "PROBLEMS" data-directory)))
416 (defun view-lossage ()
417 "Display last 100 input keystrokes.
419 To record all your input on a file, use `open-dribble-file'."
421 (help-setup-xref (list #'view-lossage) (interactive-p))
422 (with-output-to-temp-buffer (help-buffer)
423 (princ (mapconcat (lambda (key)
424 (if (or (integerp key) (symbolp key) (listp key))
425 (single-key-description key)
426 (prin1-to-string key nil)))
429 (with-current-buffer standard-output
430 (goto-char (point-min))
431 (while (progn (move-to-column 50) (not (eobp)))
432 (when (search-forward " " nil t)
435 (print-help-return-message)))
440 (defun describe-bindings (&optional prefix buffer)
441 "Show a list of all defined keys, and their definitions.
442 We put that list in a buffer, and display the buffer.
444 The optional argument PREFIX, if non-nil, should be a key sequence;
445 then we display only bindings that start with that prefix.
446 The optional argument BUFFER specifies which buffer's bindings
447 to display (default, the current buffer). BUFFER can be a buffer
450 (or buffer (setq buffer (current-buffer)))
451 (help-setup-xref (list #'describe-bindings prefix buffer) (interactive-p))
452 (with-current-buffer buffer
453 (describe-bindings-internal nil prefix)))
455 ;; This function used to be in keymap.c.
456 (defun describe-bindings-internal (&optional menus prefix)
457 "Show a list of all defined keys, and their definitions.
458 We put that list in a buffer, and display the buffer.
460 The optional argument MENUS, if non-nil, says to mention menu bindings.
461 \(Ordinarily these are omitted from the output.)
462 The optional argument PREFIX, if non-nil, should be a key sequence;
463 then we display only bindings that start with that prefix."
465 (let ((buf (current-buffer)))
466 (with-output-to-temp-buffer "*Help*"
467 (with-current-buffer standard-output
468 (describe-buffer-bindings buf prefix menus)))))
470 (defun where-is (definition &optional insert)
471 "Print message listing key sequences that invoke the command DEFINITION.
472 Argument is a command definition, usually a symbol with a function definition.
473 If INSERT (the prefix arg) is non-nil, insert the message in the buffer."
475 (let ((fn (function-called-at-point))
476 (enable-recursive-minibuffers t)
478 (setq val (completing-read
480 (format "Where is command (default %s): " fn)
481 "Where is command: ")
482 obarray 'commandp t))
483 (list (if (equal val "") fn (intern val)) current-prefix-arg)))
484 (let ((func (indirect-function definition))
486 (standard-output (if insert (current-buffer) t)))
487 ;; In DEFS, find all symbols that are aliases for DEFINITION.
488 (mapatoms (lambda (symbol)
489 (and (fboundp symbol)
490 (not (eq symbol definition))
491 (eq func (condition-case ()
492 (indirect-function symbol)
494 (push symbol defs))))
495 ;; Look at all the symbols--first DEFINITION,
497 (dolist (symbol (cons definition defs))
498 (let* ((remapped (command-remapping symbol))
499 (keys (where-is-internal
500 symbol overriding-local-map nil nil remapped))
501 (keys (mapconcat 'key-description keys ", "))
505 (if (> (length keys) 0)
507 (format "%s (%s) (remapped from %s)"
508 keys remapped symbol)
509 (format "%s (%s)" keys symbol))
510 (format "M-x %s RET" symbol))
511 (if (> (length keys) 0)
513 (format "%s is remapped to %s which is on %s"
514 symbol remapped keys)
515 (format "%s is on %s" symbol keys))
516 ;; If this is the command the user asked about,
517 ;; and it is not on any key, say so.
518 ;; For other symbols, its aliases, say nothing
519 ;; about them unless they are on keys.
520 (if (eq symbol definition)
521 (format "%s is not on any key" symbol)))))
523 (unless (eq symbol definition)
524 (princ ";\n its alias "))
528 (defun string-key-binding (key)
529 "Value is the binding of KEY in a string.
530 If KEY is an event on a string, and that string has a `local-map'
531 or `keymap' property, return the binding of KEY in the string's keymap."
533 (start (when (vectorp key)
534 (if (memq (aref key 0)
535 '(mode-line header-line left-margin right-margin))
536 (event-start (aref key 1))
537 (and (consp (aref key 0))
538 (event-start (aref key 0))))))
539 (string-info (and (consp start) (nth 4 start))))
541 (let* ((string (car string-info))
542 (pos (cdr string-info))
543 (local-map (and (>= pos 0)
544 (< pos (length string))
545 (or (get-text-property pos 'local-map string)
546 (get-text-property pos 'keymap string)))))
547 (setq defn (and local-map (lookup-key local-map key)))))
550 (defun help-key-description (key untranslated)
551 (let ((string (key-description key)))
552 (if (or (not untranslated)
553 (and (eq (aref untranslated 0) ?\e) (not (eq (aref key 0) ?\e))))
555 (let ((otherstring (key-description untranslated)))
556 (if (equal string otherstring)
558 (format "%s (translated from %s)" string otherstring))))))
560 (defun describe-key-briefly (&optional key insert untranslated)
561 "Print the name of the function KEY invokes. KEY is a string.
562 If INSERT (the prefix arg) is non-nil, insert the message in the buffer.
563 If non-nil, UNTRANSLATED is a vector of the untranslated events.
564 It can also be a number in which case the untranslated events from
565 the last key hit are used.
567 If KEY is a menu item or a tool-bar button that is disabled, this command
568 temporarily enables it to allow getting help on disabled items and buttons."
570 (let ((enable-disabled-menus-and-buttons t)
571 (cursor-in-echo-area t)
575 ;; If yank-menu is empty, populate it temporarily, so that
576 ;; "Select and Paste" menu can generate a complete event.
577 (when (null (cdr yank-menu))
578 (setq saved-yank-menu (copy-sequence yank-menu))
579 (menu-bar-update-yank-menu "(any string)" nil))
580 (setq key (read-key-sequence "Describe key (or click or menu item): "))
581 ;; If KEY is a down-event, read and discard the
582 ;; corresponding up-event.
583 (if (and (vectorp key)
585 (memq 'down (event-modifiers (elt key 0))))
589 (if current-prefix-arg (prefix-numeric-value current-prefix-arg))
591 ;; Put yank-menu back as it was, if we changed it.
592 (when saved-yank-menu
593 (setq yank-menu (copy-sequence saved-yank-menu))
594 (fset 'yank-menu (cons 'keymap yank-menu))))))
595 (if (numberp untranslated)
596 (setq untranslated (this-single-command-raw-keys)))
598 (let ((modifiers (event-modifiers (aref key 0)))
599 (standard-output (if insert (current-buffer) t))
601 ;; For a mouse button event, go to the button it applies to
602 ;; to get the right key bindings. And go to the right place
603 ;; in case the keymap depends on where you clicked.
604 (if (or (memq 'click modifiers) (memq 'down modifiers)
605 (memq 'drag modifiers))
606 (setq window (posn-window (event-start (aref key 0)))
607 position (posn-point (event-start (aref key 0)))))
610 (set-buffer (window-buffer window))
611 (goto-char position)))
612 ;; Ok, now look up the key and name the command.
613 (let ((defn (or (string-key-binding key)
614 (key-binding key t)))
616 ;; Handle the case where we faked an entry in "Select and Paste" menu.
617 (if (and (eq defn nil)
618 (stringp (aref key (1- (length key))))
619 (eq (key-binding (substring key 0 -1)) 'yank-menu))
620 (setq defn 'menu-bar-select-yank))
621 ;; Don't bother user with strings from (e.g.) the select-paste menu.
622 (if (stringp (aref key (1- (length key))))
623 (aset key (1- (length key)) "(any string)"))
624 (if (and (> (length untranslated) 0)
625 (stringp (aref untranslated (1- (length untranslated)))))
626 (aset untranslated (1- (length untranslated))
628 ;; Now describe the key, perhaps as changed.
629 (setq key-desc (help-key-description key untranslated))
630 (if (or (null defn) (integerp defn) (equal defn 'undefined))
631 (princ (format "%s is undefined" key-desc))
632 (princ (format (if (windowp window)
633 "%s at that spot runs the command %s"
634 "%s runs the command %s")
636 (if (symbolp defn) defn (prin1-to-string defn)))))))))
638 (defun describe-key (&optional key untranslated up-event)
639 "Display documentation of the function invoked by KEY.
640 KEY can be any kind of a key sequence; it can include keyboard events,
641 mouse events, and/or menu events. When calling from a program,
642 pass KEY as a string or a vector.
644 If non-nil, UNTRANSLATED is a vector of the corresponding untranslated events.
645 It can also be a number, in which case the untranslated events from
646 the last key sequence entered are used.
647 UP-EVENT is the up-event that was discarded by reading KEY, or nil.
649 If KEY is a menu item or a tool-bar button that is disabled, this command
650 temporarily enables it to allow getting help on disabled items and buttons."
652 (let ((enable-disabled-menus-and-buttons t)
653 (cursor-in-echo-area t)
657 ;; If yank-menu is empty, populate it temporarily, so that
658 ;; "Select and Paste" menu can generate a complete event.
659 (when (null (cdr yank-menu))
660 (setq saved-yank-menu (copy-sequence yank-menu))
661 (menu-bar-update-yank-menu "(any string)" nil))
662 (setq key (read-key-sequence "Describe key (or click or menu item): "))
665 (prefix-numeric-value current-prefix-arg)
666 ;; If KEY is a down-event, read the corresponding up-event
667 ;; and use it as the third argument.
668 (if (and (vectorp key)
670 (memq 'down (event-modifiers (elt key 0))))
672 ;; Put yank-menu back as it was, if we changed it.
673 (when saved-yank-menu
674 (setq yank-menu (copy-sequence saved-yank-menu))
675 (fset 'yank-menu (cons 'keymap yank-menu))))))
676 (if (numberp untranslated)
677 (setq untranslated (this-single-command-raw-keys)))
679 (let ((modifiers (event-modifiers (aref key 0)))
681 ;; For a mouse button event, go to the button it applies to
682 ;; to get the right key bindings. And go to the right place
683 ;; in case the keymap depends on where you clicked.
684 (if (or (memq 'click modifiers) (memq 'down modifiers)
685 (memq 'drag modifiers))
686 (setq window (posn-window (event-start (aref key 0)))
687 position (posn-point (event-start (aref key 0)))))
688 (when (windowp window)
689 (set-buffer (window-buffer window))
690 (goto-char position))
691 (let ((defn (or (string-key-binding key) (key-binding key t))))
692 ;; Handle the case where we faked an entry in "Select and Paste" menu.
693 (if (and (eq defn nil)
694 (stringp (aref key (1- (length key))))
695 (eq (key-binding (substring key 0 -1)) 'yank-menu))
696 (setq defn 'menu-bar-select-yank))
697 (if (or (null defn) (integerp defn) (equal defn 'undefined))
698 (message "%s is undefined" (help-key-description key untranslated))
699 (help-setup-xref (list #'describe-function defn) (interactive-p))
700 ;; Don't bother user with strings from (e.g.) the select-paste menu.
701 (if (stringp (aref key (1- (length key))))
702 (aset key (1- (length key)) "(any string)"))
703 (if (and untranslated
704 (stringp (aref untranslated (1- (length untranslated)))))
705 (aset untranslated (1- (length untranslated))
707 (with-output-to-temp-buffer (help-buffer)
708 (princ (help-key-description key untranslated))
710 (princ " at that spot"))
711 (princ " runs the command ")
713 (princ "\n which is ")
714 (describe-function-1 defn)
716 (let ((type (event-basic-type up-event))
717 (hdr "\n\n-------------- up event ---------------\n\n")
719 mouse-1-tricky mouse-1-remapped)
720 (setq sequence (vector up-event))
721 (when (and (eq type 'mouse-1)
723 mouse-1-click-follows-link
724 (not (eq mouse-1-click-follows-link 'double))
725 (setq mouse-1-remapped
726 (with-current-buffer (window-buffer window)
727 (mouse-on-link-p (posn-point
728 (event-start up-event))))))
729 (setq mouse-1-tricky (and (integerp mouse-1-click-follows-link)
730 (> mouse-1-click-follows-link 0)))
731 (cond ((stringp mouse-1-remapped)
732 (setq sequence mouse-1-remapped))
733 ((vectorp mouse-1-remapped)
734 (setcar up-event (elt mouse-1-remapped 0)))
735 (t (setcar up-event 'mouse-2))))
736 (setq defn (or (string-key-binding sequence)
737 (key-binding sequence)))
738 (unless (or (null defn) (integerp defn) (equal defn 'undefined))
739 (princ (if mouse-1-tricky
740 "\n\n----------------- up-event (short click) ----------------\n\n"
743 (princ (symbol-name type))
745 (princ " at that spot"))
747 (princ " is remapped to <mouse-2>\n which" ))
748 (princ " runs the command ")
750 (princ "\n which is ")
751 (describe-function-1 defn))
753 (setcar up-event 'mouse-1)
754 (setq defn (or (string-key-binding (vector up-event))
755 (key-binding (vector up-event))))
756 (unless (or (null defn) (integerp defn) (eq defn 'undefined))
758 "\n\n----------------- up-event (long click) ----------------\n\n"))
759 (princ "Pressing mouse-1")
761 (princ " at that spot"))
762 (princ (format " for longer than %d milli-seconds\n"
763 mouse-1-click-follows-link))
764 (princ " runs the command ")
766 (princ "\n which is ")
767 (describe-function-1 defn)))))
768 (print-help-return-message)))))))
770 (defun describe-mode (&optional buffer)
771 "Display documentation of current major mode and minor modes.
772 A brief summary of the minor modes comes first, followed by the
773 major mode description. This is followed by detailed
774 descriptions of the minor modes, each on a separate page.
776 For this to work correctly for a minor mode, the mode's indicator
777 variable \(listed in `minor-mode-alist') must also be a function
778 whose documentation describes the minor mode."
780 (unless buffer (setq buffer (current-buffer)))
781 (help-setup-xref (list #'describe-mode buffer)
783 ;; For the sake of help-do-xref and help-xref-go-back,
784 ;; don't switch buffers before calling `help-buffer'.
785 (with-output-to-temp-buffer (help-buffer)
786 (with-current-buffer buffer
788 ;; Older packages do not register in minor-mode-list but only in
790 (dolist (x minor-mode-alist)
792 (unless (memq x minor-mode-list)
793 (push x minor-mode-list)))
794 ;; Find enabled minor mode we will want to mention.
795 (dolist (mode minor-mode-list)
796 ;; Document a minor mode if it is listed in minor-mode-alist,
797 ;; non-nil, and has a function definition.
798 (let ((fmode (or (get mode :minor-mode-function) mode)))
799 (and (boundp mode) (symbol-value mode)
801 (let ((pretty-minor-mode
802 (if (string-match "\\(\\(-minor\\)?-mode\\)?\\'"
805 (substring (symbol-name fmode)
806 0 (match-beginning 0)))
808 (push (list fmode pretty-minor-mode
809 (format-mode-line (assq mode minor-mode-alist)))
813 (lambda (a b) (string-lessp (cadr a) (cadr b)))))
815 (princ "Summary of minor modes:\n")
816 (make-local-variable 'help-button-cache)
817 (with-current-buffer standard-output
818 (dolist (mode minor-modes)
819 (let ((mode-function (nth 0 mode))
820 (pretty-minor-mode (nth 1 mode))
821 (indicator (nth 2 mode)))
822 (setq indicator (if (zerop (length indicator))
824 (format "indicator%s" indicator)))
825 (add-text-properties 0 (length pretty-minor-mode)
826 '(face bold) pretty-minor-mode)
828 (goto-char (point-max))
830 (push (point-marker) help-button-cache)
831 ;; Document the minor modes fully.
832 (insert pretty-minor-mode)
833 (princ (format " minor mode (%s):\n" indicator))
834 (princ (documentation mode-function)))
836 (insert-button pretty-minor-mode
837 'action (car help-button-cache)
839 'help-echo "mouse-2, RET: show full information")
840 (princ (format " minor mode (%s):\n" indicator)))))
841 (princ "\n(Full information about these minor modes
842 follows the description of the major mode.)\n\n"))
843 ;; Document the major mode.
844 (let ((mode mode-name))
845 (with-current-buffer standard-output
846 (let ((start (point)))
847 (insert (format-mode-line mode))
848 (add-text-properties start (point) '(face bold)))))
850 (princ (documentation major-mode)))
851 (print-help-return-message))))
854 (defun describe-minor-mode (minor-mode)
855 "Display documentation of a minor mode given as MINOR-MODE.
856 MINOR-MODE can be a minor mode symbol or a minor mode indicator string
857 appeared on the mode-line."
858 (interactive (list (completing-read
861 (describe-minor-mode-completion-table-for-symbol)
862 (describe-minor-mode-completion-table-for-indicator)
864 (if (symbolp minor-mode)
865 (setq minor-mode (symbol-name minor-mode)))
866 (let ((symbols (describe-minor-mode-completion-table-for-symbol))
867 (indicators (describe-minor-mode-completion-table-for-indicator)))
869 ((member minor-mode symbols)
870 (describe-minor-mode-from-symbol (intern minor-mode)))
871 ((member minor-mode indicators)
872 (describe-minor-mode-from-indicator minor-mode))
874 (error "No such minor mode: %s" minor-mode)))))
877 (defun describe-minor-mode-completion-table-for-symbol ()
878 ;; In order to list up all minor modes, minor-mode-list
879 ;; is used here instead of minor-mode-alist.
880 (delq nil (mapcar 'symbol-name minor-mode-list)))
881 (defun describe-minor-mode-from-symbol (symbol)
882 "Display documentation of a minor mode given as a symbol, SYMBOL"
883 (interactive (list (intern (completing-read
884 "Minor mode symbol: "
885 (describe-minor-mode-completion-table-for-symbol)))))
887 (describe-function symbol)
888 (describe-variable symbol)))
891 (defun describe-minor-mode-completion-table-for-indicator ()
894 (let ((i (format-mode-line x)))
895 ;; remove first space if existed
904 (defun describe-minor-mode-from-indicator (indicator)
905 "Display documentation of a minor mode specified by INDICATOR.
906 If you call this function interactively, you can give indicator which
907 is currently activated with completion."
910 "Minor mode indicator: "
911 (describe-minor-mode-completion-table-for-indicator))))
912 (let ((minor-mode (lookup-minor-mode-from-indicator indicator)))
914 (describe-minor-mode-from-symbol minor-mode)
915 (error "Cannot find minor mode for `%s'" indicator))))
917 (defun lookup-minor-mode-from-indicator (indicator)
918 "Return a minor mode symbol from its indicator on the modeline."
919 ;; remove first space if existed
920 (if (and (< 0 (length indicator))
921 (eq (aref indicator 0) ?\ ))
922 (setq indicator (substring indicator 1)))
923 (let ((minor-modes minor-mode-alist)
926 (let* ((minor-mode (car (car minor-modes)))
927 (anindicator (format-mode-line
928 (car (cdr (car minor-modes))))))
929 ;; remove first space if existed
930 (if (and (stringp anindicator)
931 (> (length anindicator) 0)
932 (eq (aref anindicator 0) ?\ ))
933 (setq anindicator (substring anindicator 1)))
934 (if (equal indicator anindicator)
935 (setq result minor-mode
937 (setq minor-modes (cdr minor-modes)))))
941 ;;; Automatic resizing of temporary buffers.
943 (defcustom temp-buffer-max-height (lambda (buffer) (/ (- (frame-height) 2) 2))
944 "Maximum height of a window displaying a temporary buffer.
945 This is the maximum height (in text lines) which `resize-temp-buffer-window'
946 will give to a window displaying a temporary buffer.
947 It can also be a function which will be called with the object corresponding
948 to the buffer to be displayed as argument and should return an integer
950 :type '(choice integer function)
954 (define-minor-mode temp-buffer-resize-mode
955 "Toggle the mode which makes windows smaller for temporary buffers.
956 With prefix argument ARG, turn the resizing of windows displaying temporary
957 buffers on if ARG is positive or off otherwise.
958 This makes the window the right height for its contents, but never
959 more than `temp-buffer-max-height' nor less than `window-min-height'.
960 This applies to `help', `apropos' and `completion' buffers, and some others."
961 :global t :group 'help
962 (if temp-buffer-resize-mode
963 ;; `help-make-xrefs' may add a `back' button and thus increase the
964 ;; text size, so `resize-temp-buffer-window' must be run *after* it.
965 (add-hook 'temp-buffer-show-hook 'resize-temp-buffer-window 'append)
966 (remove-hook 'temp-buffer-show-hook 'resize-temp-buffer-window)))
968 (defun resize-temp-buffer-window ()
969 "Resize the current window to fit its contents.
970 Will not make it higher than `temp-buffer-max-height' nor smaller than
971 `window-min-height'. Do nothing if it is the only window on its frame, if it
972 is not as wide as the frame or if some of the window's contents are scrolled
974 (unless (or (one-window-p 'nomini)
975 (not (pos-visible-in-window-p (point-min)))
976 (/= (frame-width) (window-width)))
977 (fit-window-to-buffer
979 (if (functionp temp-buffer-max-height)
980 (funcall temp-buffer-max-height (current-buffer))
981 temp-buffer-max-height))))
986 ;; arch-tag: cf427352-27e9-49b7-9a6f-741ebab02423
987 ;;; help.el ends here