Commit | Line | Data |
---|---|---|
1a06eabd ER |
1 | ;;; help.el --- help commands for Emacs |
2 | ||
754084bb GM |
3 | ;; Copyright (C) 1985, 1986, 1993, 1994, 1998, 1999, 2000, 2001 |
4 | ;; Free Software Foundation, Inc. | |
3a801d0c | 5 | |
e5167999 | 6 | ;; Maintainer: FSF |
fd7fa35a | 7 | ;; Keywords: help, internal |
e5167999 | 8 | |
433ae6f6 RS |
9 | ;; This file is part of GNU Emacs. |
10 | ||
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 | |
e5167999 | 13 | ;; the Free Software Foundation; either version 2, or (at your option) |
433ae6f6 RS |
14 | ;; any later version. |
15 | ||
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. | |
20 | ||
21 | ;; You should have received a copy of the GNU General Public License | |
b578f267 EN |
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. | |
433ae6f6 | 25 | |
d9ecc911 ER |
26 | ;;; Commentary: |
27 | ||
a1c9f209 | 28 | ;; This code implements GNU Emacs' on-line help system, the one invoked by |
95ac0a6f | 29 | ;; `M-x help-for-help'. |
d9ecc911 | 30 | |
e5167999 ER |
31 | ;;; Code: |
32 | ||
8aa3a187 RS |
33 | ;; Get the macro make-help-screen when this is compiled, |
34 | ;; or run interpreted, but not when the compiled code is loaded. | |
b1fe9304 | 35 | (eval-when-compile (require 'help-macro)) |
788d62cf MB |
36 | |
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) | |
41b8542b | 40 | |
433ae6f6 RS |
41 | (defvar help-map (make-sparse-keymap) |
42 | "Keymap for characters following the Help key.") | |
43 | ||
e17d2fd1 | 44 | (define-key global-map (char-to-string help-char) 'help-command) |
0af3df1c RS |
45 | (define-key global-map [help] 'help-command) |
46 | (define-key global-map [f1] 'help-command) | |
433ae6f6 RS |
47 | (fset 'help-command help-map) |
48 | ||
e17d2fd1 | 49 | (define-key help-map (char-to-string help-char) 'help-for-help) |
0af3df1c RS |
50 | (define-key help-map [help] 'help-for-help) |
51 | (define-key help-map [f1] 'help-for-help) | |
433ae6f6 RS |
52 | (define-key help-map "?" 'help-for-help) |
53 | ||
54 | (define-key help-map "\C-c" 'describe-copying) | |
55 | (define-key help-map "\C-d" 'describe-distribution) | |
4f16ea85 RS |
56 | (define-key help-map "\C-e" 'view-emacs-problems) |
57 | (define-key help-map "\C-f" 'view-emacs-FAQ) | |
58 | (define-key help-map "\C-h" 'view-hello-file) | |
59 | (define-key help-map "\C-m" 'view-order-manuals) | |
60 | (define-key help-map "\C-n" 'view-emacs-news) | |
76766f2d | 61 | (define-key help-map "\C-p" 'describe-project) |
4f16ea85 RS |
62 | (define-key help-map "\C-w" 'describe-no-warranty) |
63 | ||
64 | ;; This does not fit the pattern, but it is natural given the C-\ command. | |
65 | (define-key help-map "\C-\\" 'describe-input-method) | |
66 | ||
67 | (define-key help-map "C" 'describe-coding-system) | |
68 | (define-key help-map "F" 'Info-goto-emacs-command-node) | |
69 | (define-key help-map "I" 'describe-input-method) | |
70 | (define-key help-map "K" 'Info-goto-emacs-key-command-node) | |
71 | (define-key help-map "L" 'describe-language-environment) | |
72 | (define-key help-map "S" 'info-lookup-symbol) | |
73 | ||
122955bf | 74 | (define-key help-map "a" 'apropos-command) |
433ae6f6 RS |
75 | |
76 | (define-key help-map "b" 'describe-bindings) | |
77 | ||
78 | (define-key help-map "c" 'describe-key-briefly) | |
433ae6f6 | 79 | |
4f16ea85 RS |
80 | (define-key help-map "e" 'view-echo-area-messages) |
81 | ||
433ae6f6 RS |
82 | (define-key help-map "f" 'describe-function) |
83 | ||
4f16ea85 | 84 | (define-key help-map "h" 'view-hello-file) |
7ee71cf1 | 85 | |
433ae6f6 | 86 | (define-key help-map "i" 'info) |
4b08b7ed | 87 | (define-key help-map "4i" 'info-other-window) |
4f16ea85 RS |
88 | |
89 | (define-key help-map "k" 'describe-key) | |
433ae6f6 RS |
90 | |
91 | (define-key help-map "l" 'view-lossage) | |
92 | ||
93 | (define-key help-map "m" 'describe-mode) | |
94 | ||
433ae6f6 RS |
95 | (define-key help-map "n" 'view-emacs-news) |
96 | ||
06b98c51 | 97 | (define-key help-map "p" 'finder-by-keyword) |
3e9c095d RS |
98 | (autoload 'finder-by-keyword "finder" |
99 | "Find packages matching a given keyword." t) | |
06b98c51 | 100 | |
433ae6f6 RS |
101 | (define-key help-map "s" 'describe-syntax) |
102 | ||
103 | (define-key help-map "t" 'help-with-tutorial) | |
104 | ||
105 | (define-key help-map "w" 'where-is) | |
106 | ||
107 | (define-key help-map "v" 'describe-variable) | |
108 | ||
2fc9d9f4 RS |
109 | (define-key help-map "q" 'help-quit) |
110 | ||
0cf0d828 | 111 | \f |
2fc9d9f4 | 112 | (defun help-quit () |
3120a677 | 113 | "Just exit from the Help command's command loop." |
2fc9d9f4 RS |
114 | (interactive) |
115 | nil) | |
116 | ||
01364a75 RS |
117 | (defvar help-return-method nil |
118 | "What to do to \"exit\" the help buffer. | |
119 | This is a list | |
120 | (WINDOW . t) delete the selected window, go to WINDOW. | |
121 | (WINDOW . quit-window) do quit-window, then select WINDOW. | |
122 | (WINDOW BUF START POINT) display BUF at START, POINT, then select WINDOW.") | |
123 | ||
433ae6f6 RS |
124 | (defun print-help-return-message (&optional function) |
125 | "Display or return message saying how to restore windows after help command. | |
126 | Computes a message and applies the optional argument FUNCTION to it. | |
127 | If FUNCTION is nil, applies `message' to it, thus printing it." | |
128 | (and (not (get-buffer-window standard-output)) | |
d536293f | 129 | (let ((first-message |
a1c9f209 | 130 | (cond ((special-display-p (buffer-name standard-output)) |
01364a75 | 131 | (setq help-return-method (cons (selected-window) t)) |
d536293f RS |
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. | |
d536293f | 138 | nil) |
f3ad2fc8 GM |
139 | (display-buffer-reuse-frames |
140 | (setq help-return-method (cons (selected-window) | |
141 | 'quit-window)) | |
142 | nil) | |
d536293f | 143 | ((not (one-window-p t)) |
01364a75 RS |
144 | (setq help-return-method |
145 | (cons (selected-window) 'quit-window)) | |
d536293f RS |
146 | "Type \\[switch-to-buffer-other-window] RET to restore the other window.") |
147 | (pop-up-windows | |
01364a75 | 148 | (setq help-return-method (cons (selected-window) t)) |
d536293f RS |
149 | "Type \\[delete-other-windows] to remove help window.") |
150 | (t | |
01364a75 RS |
151 | (setq help-return-method |
152 | (list (selected-window) (window-buffer) | |
153 | (window-start) (window-point))) | |
d536293f RS |
154 | "Type \\[switch-to-buffer] RET to remove help window.")))) |
155 | (funcall (or function 'message) | |
156 | (concat | |
157 | (if first-message | |
376b2a24 DL |
158 | (substitute-command-keys first-message)) |
159 | (if first-message " ") | |
125a8d70 RS |
160 | ;; If the help buffer will go in a separate frame, |
161 | ;; it's no use mentioning a command to scroll, so don't. | |
a1c9f209 | 162 | (if (special-display-p (buffer-name standard-output)) |
125a8d70 | 163 | nil |
a1c9f209 | 164 | (if (same-window-p (buffer-name standard-output)) |
125a8d70 RS |
165 | ;; Say how to scroll this window. |
166 | (substitute-command-keys | |
167 | "\\[scroll-up] to scroll the help.") | |
168 | ;; Say how to scroll some other window. | |
6e7f5182 | 169 | (substitute-command-keys |
125a8d70 | 170 | "\\[scroll-other-window] to scroll the help.")))))))) |
433ae6f6 | 171 | |
433ae6f6 RS |
172 | ;; So keyboard macro definitions are documented correctly |
173 | (fset 'defining-kbd-macro (symbol-function 'start-kbd-macro)) | |
174 | ||
788d62cf MB |
175 | (defalias 'help 'help-for-help) |
176 | (make-help-screen help-for-help | |
4f16ea85 | 177 | "a b c C e f F C-f i I k C-k l L m p s t v w C-c C-d C-n C-p C-w or ? :" |
788d62cf MB |
178 | "You have typed %THIS-KEY%, the help character. Type a Help option: |
179 | \(Use SPC or DEL to scroll through this text. Type \\<help-map>\\[help-quit] to exit the Help command.) | |
180 | ||
181 | a command-apropos. Give a substring, and see a list of commands | |
182 | (functions interactively callable) that contain | |
183 | that substring. See also the apropos command. | |
184 | b describe-bindings. Display table of all key bindings. | |
185 | c describe-key-briefly. Type a command key sequence; | |
186 | it prints the function name that sequence runs. | |
187 | C describe-coding-system. This describes either a specific coding system | |
188 | (if you type its name) or the coding systems currently in use | |
189 | (if you type just RET). | |
4f16ea85 | 190 | e view-echo-area-messages. Show the `*Messages*' buffer. |
788d62cf | 191 | f describe-function. Type a function name and get documentation of it. |
4f16ea85 | 192 | F Info-goto-emacs-command-node. Type a function name; |
788d62cf MB |
193 | it takes you to the Info node for that command. |
194 | i info. The info documentation reader. | |
195 | I describe-input-method. Describe a specific input method (if you type | |
196 | its name) or the current input method (if you type just RET). | |
788d62cf MB |
197 | k describe-key. Type a command key sequence; |
198 | it displays the full documentation. | |
4f16ea85 | 199 | K Info-goto-emacs-key-command-node. Type a command key sequence; |
788d62cf MB |
200 | it takes you to the Info node for the command bound to that key. |
201 | l view-lossage. Show last 100 characters you typed. | |
202 | L describe-language-environment. This describes either a | |
203 | specific language environment (if you type its name) | |
204 | or the current language environment (if you type just RET). | |
205 | m describe-mode. Print documentation of current minor modes, | |
206 | and the current major mode, including their special commands. | |
788d62cf MB |
207 | p finder-by-keyword. Find packages matching a given topic keyword. |
208 | s describe-syntax. Display contents of syntax table, plus explanations. | |
4f16ea85 RS |
209 | S info-lookup-symbol. Display the definition of a specific symbol |
210 | as found in the manual for the language this buffer is written in. | |
788d62cf MB |
211 | t help-with-tutorial. Select the Emacs learn-by-doing tutorial. |
212 | v describe-variable. Type name of a variable; | |
213 | it displays the variable's documentation and value. | |
214 | w where-is. Type command name; it prints which keystrokes | |
215 | invoke that command. | |
216 | ||
4f16ea85 | 217 | C-c Display Emacs copying permission (GNU General Public License). |
788d62cf | 218 | C-d Display Emacs ordering information. |
4f16ea85 RS |
219 | C-e Display info about Emacs problems. |
220 | C-f Display the Emacs FAQ. | |
221 | C-h Display the HELLO file which illustrates various scripts. | |
222 | C-m Display how to order printed Emacs manuals. | |
788d62cf MB |
223 | C-n Display news of recent Emacs changes. |
224 | C-p Display information about the GNU project. | |
225 | C-w Display information on absence of warranty for GNU Emacs." | |
226 | help-map) | |
227 | ||
228 | \f | |
229 | ||
230 | (defun function-called-at-point () | |
231 | "Return a function around point or else called by the list containing point. | |
232 | If that doesn't give a function, return nil." | |
233 | (with-syntax-table emacs-lisp-mode-syntax-table | |
234 | (or (condition-case () | |
235 | (save-excursion | |
236 | (or (not (zerop (skip-syntax-backward "_w"))) | |
237 | (eq (char-syntax (following-char)) ?w) | |
238 | (eq (char-syntax (following-char)) ?_) | |
239 | (forward-sexp -1)) | |
240 | (skip-chars-forward "'") | |
241 | (let ((obj (read (current-buffer)))) | |
242 | (and (symbolp obj) (fboundp obj) obj))) | |
243 | (error nil)) | |
244 | (condition-case () | |
245 | (save-excursion | |
246 | (save-restriction | |
247 | (narrow-to-region (max (point-min) | |
248 | (- (point) 1000)) (point-max)) | |
249 | ;; Move up to surrounding paren, then after the open. | |
250 | (backward-up-list 1) | |
251 | (forward-char 1) | |
252 | ;; If there is space here, this is probably something | |
253 | ;; other than a real Lisp function call, so ignore it. | |
254 | (if (looking-at "[ \t]") | |
255 | (error "Probably not a Lisp function call")) | |
256 | (let ((obj (read (current-buffer)))) | |
257 | (and (symbolp obj) (fboundp obj) obj)))) | |
258 | (error nil))))) | |
259 | ||
260 | \f | |
261 | ;;; `User' help functions | |
262 | ||
433ae6f6 RS |
263 | (defun describe-distribution () |
264 | "Display info on how to obtain the latest version of GNU Emacs." | |
265 | (interactive) | |
64f3b7d3 | 266 | (view-find (expand-file-name "DISTRIB" data-directory))) |
433ae6f6 RS |
267 | |
268 | (defun describe-copying () | |
269 | "Display info on how you may redistribute copies of GNU Emacs." | |
270 | (interactive) | |
64f3b7d3 | 271 | (view-file (expand-file-name "COPYING" data-directory)) |
433ae6f6 RS |
272 | (goto-char (point-min))) |
273 | ||
76766f2d RS |
274 | (defun describe-project () |
275 | "Display info on the GNU project." | |
276 | (interactive) | |
64f3b7d3 | 277 | (view-file (expand-file-name "THE-GNU-PROJECT" data-directory)) |
76766f2d RS |
278 | (goto-char (point-min))) |
279 | ||
433ae6f6 RS |
280 | (defun describe-no-warranty () |
281 | "Display info on all the kinds of warranty Emacs does NOT have." | |
282 | (interactive) | |
283 | (describe-copying) | |
284 | (let (case-fold-search) | |
285 | (search-forward "NO WARRANTY") | |
286 | (recenter 0))) | |
287 | ||
61c6b658 | 288 | (defun describe-prefix-bindings () |
c7cba9cb RS |
289 | "Describe the bindings of the prefix used to reach this command. |
290 | The prefix described consists of all but the last event | |
291 | of the key sequence that ran this command." | |
61c6b658 | 292 | (interactive) |
ccc06dcc KH |
293 | (let* ((key (this-command-keys))) |
294 | (describe-bindings | |
295 | (if (stringp key) | |
296 | (substring key 0 (1- (length key))) | |
297 | (let ((prefix (make-vector (1- (length key)) nil)) | |
298 | (i 0)) | |
299 | (while (< i (length prefix)) | |
300 | (aset prefix i (aref key i)) | |
301 | (setq i (1+ i))) | |
302 | prefix))))) | |
788d62cf | 303 | ;; Make C-h after a prefix, when not specifically bound, |
c7cba9cb | 304 | ;; run describe-prefix-bindings. |
61c6b658 RS |
305 | (setq prefix-help-command 'describe-prefix-bindings) |
306 | ||
382d018a RS |
307 | (defun view-emacs-news (&optional arg) |
308 | "Display info on recent changes to Emacs. | |
f0753a5f | 309 | With numeric argument, display information on correspondingly older changes." |
382d018a | 310 | (interactive "P") |
f0753a5f GM |
311 | (let* ((arg (if arg (prefix-numeric-value arg) 0)) |
312 | (file (cond ((eq arg 0) "NEWS") | |
313 | ((eq arg 1) "ONEWS") | |
314 | (t | |
315 | (nth (- arg 2) | |
316 | (nreverse (directory-files data-directory | |
975f82c9 | 317 | nil "^ONEWS\\.[0-9]+$" |
f0753a5f GM |
318 | nil))))))) |
319 | (if file | |
64f3b7d3 | 320 | (view-file (expand-file-name file data-directory)) |
f0753a5f | 321 | (error "No such old news")))) |
433ae6f6 | 322 | |
4f16ea85 RS |
323 | (defun view-echo-area-messages () |
324 | "View the log of recent echo-area messages: the `*Messages*' buffer. | |
325 | The number of messages retained in that buffer | |
326 | is specified by the variable `message-log-max'." | |
327 | (interactive) | |
328 | (switch-to-buffer (get-buffer-create "*Messages*"))) | |
329 | ||
754084bb GM |
330 | (defun view-order-manuals () |
331 | "Display the Emacs ORDERS file." | |
332 | (interactive) | |
64f3b7d3 | 333 | (view-file (expand-file-name "ORDERS" data-directory)) |
38790755 | 334 | (goto-address)) |
754084bb | 335 | |
7ee71cf1 RS |
336 | (defun view-emacs-FAQ () |
337 | "Display the Emacs Frequently Asked Questions (FAQ) file." | |
338 | (interactive) | |
94ea540b | 339 | ;; (find-file-read-only (expand-file-name "FAQ" data-directory)) |
279b772d | 340 | (info "(efaq)")) |
7ee71cf1 | 341 | |
4cbff657 DL |
342 | (defun view-emacs-problems () |
343 | "Display info on known problems with Emacs and possible workarounds." | |
344 | (interactive) | |
345 | (view-file (expand-file-name "PROBLEMS" data-directory))) | |
346 | ||
433ae6f6 | 347 | (defun view-lossage () |
50b57199 EZ |
348 | "Display last 100 input keystrokes. |
349 | ||
350 | To record all your input on a file, use `open-dribble-file'." | |
433ae6f6 | 351 | (interactive) |
3e5929af SM |
352 | (help-setup-xref (list #'view-lossage) (interactive-p)) |
353 | (with-output-to-temp-buffer (help-buffer) | |
298a7c8c RS |
354 | (princ (mapconcat (function (lambda (key) |
355 | (if (or (integerp key) | |
356 | (symbolp key) | |
357 | (listp key)) | |
358 | (single-key-description key) | |
359 | (prin1-to-string key nil)))) | |
360 | (recent-keys) | |
361 | " ")) | |
b0fbf754 | 362 | (with-current-buffer standard-output |
433ae6f6 RS |
363 | (goto-char (point-min)) |
364 | (while (progn (move-to-column 50) (not (eobp))) | |
365 | (search-forward " " nil t) | |
3e5929af | 366 | (insert "\n"))) |
433ae6f6 RS |
367 | (print-help-return-message))) |
368 | ||
788d62cf MB |
369 | \f |
370 | ;; Key bindings | |
433ae6f6 | 371 | |
4c45295b | 372 | (defun describe-bindings (&optional prefix buffer) |
a8ad43aa RS |
373 | "Show a list of all defined keys, and their definitions. |
374 | We put that list in a buffer, and display the buffer. | |
375 | ||
376 | The optional argument PREFIX, if non-nil, should be a key sequence; | |
4c45295b KH |
377 | then we display only bindings that start with that prefix. |
378 | The optional argument BUFFER specifies which buffer's bindings | |
379 | to display (default, the current buffer)." | |
3e5929af | 380 | (interactive) |
4c45295b | 381 | (or buffer (setq buffer (current-buffer))) |
3e5929af | 382 | (help-setup-xref (list #'describe-bindings prefix buffer) (interactive-p)) |
4c45295b | 383 | (with-current-buffer buffer |
3e5929af | 384 | (describe-bindings-internal nil prefix))) |
a8ad43aa | 385 | |
94ea540b SM |
386 | ;; This function used to be in keymap.c. |
387 | (defun describe-bindings-internal (&optional menus prefix) | |
388 | "Show a list of all defined keys, and their definitions. | |
389 | We put that list in a buffer, and display the buffer. | |
390 | ||
391 | The optional argument MENUS, if non-nil, says to mention menu bindings. | |
392 | \(Ordinarily these are omitted from the output.) | |
393 | The optional argument PREFIX, if non-nil, should be a key sequence; | |
394 | then we display only bindings that start with that prefix." | |
395 | (interactive) | |
396 | (let ((buf (current-buffer))) | |
397 | (with-output-to-temp-buffer "*Help*" | |
398 | (with-current-buffer standard-output | |
399 | (describe-buffer-bindings buf prefix menus))))) | |
400 | ||
e88a2c59 | 401 | (defun where-is (definition &optional insert) |
b2c85790 | 402 | "Print message listing key sequences that invoke the command DEFINITION. |
e88a2c59 RS |
403 | Argument is a command definition, usually a symbol with a function definition. |
404 | If INSERT (the prefix arg) is non-nil, insert the message in the buffer." | |
54c0b967 RS |
405 | (interactive |
406 | (let ((fn (function-called-at-point)) | |
788d62cf | 407 | (enable-recursive-minibuffers t) |
54c0b967 RS |
408 | val) |
409 | (setq val (completing-read (if fn | |
410 | (format "Where is command (default %s): " fn) | |
411 | "Where is command: ") | |
d5f65532 | 412 | obarray 'commandp t)) |
54c0b967 | 413 | (list (if (equal val "") |
e88a2c59 RS |
414 | fn (intern val)) |
415 | current-prefix-arg))) | |
54c0b967 | 416 | (let* ((keys (where-is-internal definition overriding-local-map nil nil)) |
e88a2c59 RS |
417 | (keys1 (mapconcat 'key-description keys ", ")) |
418 | (standard-output (if insert (current-buffer) t))) | |
419 | (if insert | |
420 | (if (> (length keys1) 0) | |
421 | (princ (format "%s (%s)" keys1 definition)) | |
422 | (princ (format "M-x %s RET" definition))) | |
423 | (if (> (length keys1) 0) | |
424 | (princ (format "%s is on %s" definition keys1)) | |
425 | (princ (format "%s is not on any key" definition))))) | |
54c0b967 RS |
426 | nil) |
427 | ||
788d62cf MB |
428 | (defun string-key-binding (key) |
429 | "Value is the binding of KEY in a string. | |
430 | If KEY is an event on a string, and that string has a `local-map' | |
431 | or `keymap' property, return the binding of KEY in the string's keymap." | |
432 | (let* ((defn nil) | |
433 | (start (when (vectorp key) | |
434 | (if (memq (aref key 0) '(mode-line header-line)) | |
435 | (event-start (aref key 1)) | |
436 | (and (consp (aref key 0)) | |
437 | (event-start (aref key 0)))))) | |
438 | (string-info (and (consp start) (nth 4 start)))) | |
439 | (when string-info | |
440 | (let* ((string (car string-info)) | |
441 | (pos (cdr string-info)) | |
442 | (local-map (and (> pos 0) | |
443 | (< pos (length string)) | |
444 | (or (get-text-property pos 'local-map string) | |
445 | (get-text-property pos 'keymap string))))) | |
446 | (setq defn (and local-map (lookup-key local-map key))))) | |
447 | defn)) | |
1a06eabd | 448 | |
788d62cf MB |
449 | (defun describe-key-briefly (key &optional insert) |
450 | "Print the name of the function KEY invokes. KEY is a string. | |
451 | If INSERT (the prefix arg) is non-nil, insert the message in the buffer." | |
452 | (interactive "kDescribe key briefly: \nP") | |
400a1b1f | 453 | (save-excursion |
788d62cf MB |
454 | (let ((modifiers (event-modifiers (aref key 0))) |
455 | (standard-output (if insert (current-buffer) t)) | |
456 | window position) | |
457 | ;; For a mouse button event, go to the button it applies to | |
458 | ;; to get the right key bindings. And go to the right place | |
459 | ;; in case the keymap depends on where you clicked. | |
460 | (if (or (memq 'click modifiers) (memq 'down modifiers) | |
461 | (memq 'drag modifiers)) | |
462 | (setq window (posn-window (event-start (aref key 0))) | |
463 | position (posn-point (event-start (aref key 0))))) | |
464 | (if (windowp window) | |
465 | (progn | |
466 | (set-buffer (window-buffer window)) | |
467 | (goto-char position))) | |
468 | ;; Ok, now look up the key and name the command. | |
469 | (let ((defn (or (string-key-binding key) | |
470 | (key-binding key))) | |
471 | (key-desc (key-description key))) | |
472 | (if (or (null defn) (integerp defn)) | |
473 | (princ (format "%s is undefined" key-desc)) | |
474 | (princ (format (if insert | |
475 | "`%s' (`%s')" | |
476 | (if (windowp window) | |
477 | "%s at that spot runs the command %s" | |
478 | "%s runs the command %s")) | |
479 | key-desc | |
480 | (if (symbolp defn) defn (prin1-to-string defn))))))))) | |
96ede6b2 | 481 | |
788d62cf MB |
482 | |
483 | (defun describe-key (key) | |
a0d32c10 RS |
484 | "Display documentation of the function invoked by KEY. |
485 | KEY should be a key sequence--when calling from a program, | |
486 | pass a string or a vector." | |
788d62cf MB |
487 | (interactive "kDescribe key: ") |
488 | (save-excursion | |
489 | (let ((modifiers (event-modifiers (aref key 0))) | |
490 | window position) | |
491 | ;; For a mouse button event, go to the button it applies to | |
492 | ;; to get the right key bindings. And go to the right place | |
493 | ;; in case the keymap depends on where you clicked. | |
494 | (if (or (memq 'click modifiers) (memq 'down modifiers) | |
495 | (memq 'drag modifiers)) | |
496 | (setq window (posn-window (event-start (aref key 0))) | |
497 | position (posn-point (event-start (aref key 0))))) | |
94ea540b | 498 | (when (windowp window) |
788d62cf | 499 | (set-buffer (window-buffer window)) |
94ea540b | 500 | (goto-char position)) |
788d62cf MB |
501 | (let ((defn (or (string-key-binding key) (key-binding key)))) |
502 | (if (or (null defn) (integerp defn)) | |
503 | (message "%s is undefined" (key-description key)) | |
3e5929af SM |
504 | (help-setup-xref (list #'describe-function defn) (interactive-p)) |
505 | (with-output-to-temp-buffer (help-buffer) | |
788d62cf MB |
506 | (princ (key-description key)) |
507 | (if (windowp window) | |
508 | (princ " at that spot")) | |
509 | (princ " runs the command ") | |
510 | (prin1 defn) | |
511 | (princ "\n which is ") | |
3e5929af | 512 | (describe-function-1 defn) |
788d62cf | 513 | (print-help-return-message))))))) |
400a1b1f | 514 | |
400a1b1f | 515 | \f |
788d62cf MB |
516 | (defun describe-mode (&optional buffer) |
517 | "Display documentation of current major mode and minor modes. | |
518 | The major mode description comes first, followed by the minor modes, | |
519 | each on a separate page. | |
520 | For this to work correctly for a minor mode, the mode's indicator variable | |
521 | \(listed in `minor-mode-alist') must also be a function whose documentation | |
522 | describes the minor mode." | |
400a1b1f | 523 | (interactive) |
9639be74 RS |
524 | (help-setup-xref (list #'describe-mode (or buffer (current-buffer))) |
525 | (interactive-p)) | |
526 | ;; For the sake of help-do-xref and help-xref-go-back, | |
527 | ;; don't switch buffers before calling `help-buffer'. | |
3e5929af | 528 | (with-output-to-temp-buffer (help-buffer) |
9639be74 RS |
529 | (save-excursion |
530 | (when buffer (set-buffer buffer)) | |
531 | (when minor-mode-alist | |
532 | (princ "The major mode is described first. | |
788d62cf | 533 | For minor modes, see following pages.\n\n")) |
9639be74 RS |
534 | (princ mode-name) |
535 | (princ " mode:\n") | |
536 | (princ (documentation major-mode)) | |
537 | (let ((minor-modes minor-mode-alist)) | |
538 | (while minor-modes | |
539 | (let* ((minor-mode (car (car minor-modes))) | |
540 | (indicator (car (cdr (car minor-modes))))) | |
541 | ;; Document a minor mode if it is listed in minor-mode-alist, | |
542 | ;; bound locally in this buffer, non-nil, and has a function | |
543 | ;; definition. | |
544 | (if (and (boundp minor-mode) | |
545 | (symbol-value minor-mode) | |
546 | (fboundp minor-mode)) | |
547 | (let ((pretty-minor-mode minor-mode)) | |
548 | (if (string-match "\\(-minor\\)?-mode\\'" | |
549 | (symbol-name minor-mode)) | |
550 | (setq pretty-minor-mode | |
551 | (capitalize | |
552 | (substring (symbol-name minor-mode) | |
553 | 0 (match-beginning 0))))) | |
554 | (while (and indicator (symbolp indicator) | |
555 | (boundp indicator) | |
556 | (not (eq indicator (symbol-value indicator)))) | |
557 | (setq indicator (symbol-value indicator))) | |
558 | (princ "\n\f\n") | |
559 | (princ (format "%s minor mode (%s):\n" | |
560 | pretty-minor-mode | |
561 | (if indicator | |
562 | (format "indicator%s" indicator) | |
563 | "no indicator"))) | |
564 | (princ (documentation minor-mode))))) | |
565 | (setq minor-modes (cdr minor-modes)))) | |
566 | (print-help-return-message)))) | |
400a1b1f | 567 | |
48ce3c22 RS |
568 | \f |
569 | ;;; Automatic resizing of temporary buffers. | |
570 | ||
4483ddc5 | 571 | (defcustom temp-buffer-max-height (lambda (buffer) (/ (- (frame-height) 2) 2)) |
48ce3c22 RS |
572 | "*Maximum height of a window displaying a temporary buffer. |
573 | This is the maximum height (in text lines) which `resize-temp-buffer-window' | |
574 | will give to a window displaying a temporary buffer. | |
575 | It can also be a function which will be called with the object corresponding | |
576 | to the buffer to be displayed as argument and should return an integer | |
577 | positive number." | |
578 | :type '(choice integer function) | |
579 | :group 'help | |
580 | :version "20.4") | |
581 | ||
4e1ede6c SM |
582 | (define-minor-mode temp-buffer-resize-mode |
583 | "Toggle the mode which makes windows smaller for temporary buffers. | |
48ce3c22 RS |
584 | With prefix argument ARG, turn the resizing of windows displaying temporary |
585 | buffers on if ARG is positive or off otherwise. | |
4e1ede6c SM |
586 | This makes the window the right height for its contents, but never |
587 | more than `temp-buffer-max-height' nor less than `window-min-height'. | |
588 | This applies to `help', `apropos' and `completion' buffers, and some others." | |
b0fbf754 | 589 | :global t :group 'help |
4e1ede6c | 590 | (if temp-buffer-resize-mode |
57f43907 | 591 | ;; `help-make-xrefs' may add a `back' button and thus increase the |
4e1ede6c SM |
592 | ;; text size, so `resize-temp-buffer-window' must be run *after* it. |
593 | (add-hook 'temp-buffer-show-hook 'resize-temp-buffer-window 'append) | |
8304a3bb | 594 | (remove-hook 'temp-buffer-show-hook 'resize-temp-buffer-window))) |
48ce3c22 RS |
595 | |
596 | (defun resize-temp-buffer-window () | |
597 | "Resize the current window to fit its contents. | |
4483ddc5 | 598 | Will not make it higher than `temp-buffer-max-height' nor smaller than |
b2c85790 | 599 | `window-min-height'. Do nothing if it is the only window on its frame, if it |
48ce3c22 RS |
600 | is not as wide as the frame or if some of the window's contents are scrolled |
601 | out of view." | |
602 | (unless (or (one-window-p 'nomini) | |
603 | (not (pos-visible-in-window-p (point-min))) | |
604 | (/= (frame-width) (window-width))) | |
d9c30bdf MB |
605 | (fit-window-to-buffer |
606 | (selected-window) | |
607 | (if (functionp temp-buffer-max-height) | |
608 | (funcall temp-buffer-max-height (current-buffer)) | |
609 | temp-buffer-max-height)))) | |
48ce3c22 | 610 | |
5fbeea74 GM |
611 | ;; Provide this for the sake of define-minor-mode which generates |
612 | ;; defcustoms which require 'help'. | |
5fbeea74 GM |
613 | (provide 'help) |
614 | ||
1a06eabd | 615 | ;;; help.el ends here |