| 1 | ;;; help.el --- help commands for Emacs |
| 2 | |
| 3 | ;; Copyright (C) 1985, 1986, 1993, 1994, 1998, 1999, 2000, 2001, 2002, |
| 4 | ;; 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc. |
| 5 | |
| 6 | ;; Maintainer: FSF |
| 7 | ;; Keywords: help, internal |
| 8 | |
| 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 |
| 13 | ;; the Free Software Foundation; either version 3, or (at your option) |
| 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 |
| 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. |
| 25 | |
| 26 | ;;; Commentary: |
| 27 | |
| 28 | ;; This code implements GNU Emacs' on-line help system, the one invoked by |
| 29 | ;; `M-x help-for-help'. |
| 30 | |
| 31 | ;;; Code: |
| 32 | |
| 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)) |
| 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) |
| 40 | |
| 41 | (defvar help-map |
| 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) |
| 48 | |
| 49 | (define-key map "\C-a" 'about-emacs) |
| 50 | (define-key map "\C-c" 'describe-copying) |
| 51 | (define-key map "\C-d" 'describe-distribution) |
| 52 | (define-key map "\C-e" 'view-emacs-problems) |
| 53 | (define-key map "\C-f" 'view-emacs-FAQ) |
| 54 | (define-key map "\C-m" 'view-order-manuals) |
| 55 | (define-key map "\C-n" 'view-emacs-news) |
| 56 | (define-key map "\C-p" 'describe-project) |
| 57 | (define-key map "\C-t" 'view-todo) |
| 58 | (define-key map "\C-w" 'describe-no-warranty) |
| 59 | |
| 60 | ;; This does not fit the pattern, but it is natural given the C-\ command. |
| 61 | (define-key map "\C-\\" 'describe-input-method) |
| 62 | |
| 63 | (define-key map "C" 'describe-coding-system) |
| 64 | (define-key map "F" 'Info-goto-emacs-command-node) |
| 65 | (define-key map "I" 'describe-input-method) |
| 66 | (define-key map "K" 'Info-goto-emacs-key-command-node) |
| 67 | (define-key map "L" 'describe-language-environment) |
| 68 | (define-key map "S" 'info-lookup-symbol) |
| 69 | |
| 70 | (define-key map "a" 'apropos-command) |
| 71 | (define-key map "b" 'describe-bindings) |
| 72 | (define-key map "c" 'describe-key-briefly) |
| 73 | (define-key map "d" 'apropos-documentation) |
| 74 | (define-key map "e" 'view-echo-area-messages) |
| 75 | (define-key map "f" 'describe-function) |
| 76 | (define-key map "h" 'view-hello-file) |
| 77 | |
| 78 | (define-key map "i" 'info) |
| 79 | (define-key map "4i" 'info-other-window) |
| 80 | |
| 81 | (define-key map "k" 'describe-key) |
| 82 | (define-key map "l" 'view-lossage) |
| 83 | (define-key map "m" 'describe-mode) |
| 84 | (define-key map "n" 'view-emacs-news) |
| 85 | (define-key map "p" 'finder-by-keyword) |
| 86 | (define-key map "r" 'info-emacs-manual) |
| 87 | (define-key map "s" 'describe-syntax) |
| 88 | (define-key map "t" 'help-with-tutorial) |
| 89 | (define-key map "w" 'where-is) |
| 90 | (define-key map "v" 'describe-variable) |
| 91 | (define-key map "q" 'help-quit) |
| 92 | map) |
| 93 | "Keymap for characters following the Help key.") |
| 94 | |
| 95 | (define-key global-map (char-to-string help-char) 'help-command) |
| 96 | (define-key global-map [help] 'help-command) |
| 97 | (define-key global-map [f1] 'help-command) |
| 98 | (fset 'help-command help-map) |
| 99 | |
| 100 | (autoload 'finder-by-keyword "finder" |
| 101 | "Find packages matching a given keyword." t) |
| 102 | |
| 103 | ;; insert-button makes the action nil if it is not store somewhere |
| 104 | (defvar help-button-cache nil) |
| 105 | |
| 106 | \f |
| 107 | (defun help-quit () |
| 108 | "Just exit from the Help command's command loop." |
| 109 | (interactive) |
| 110 | nil) |
| 111 | |
| 112 | (defvar help-return-method nil |
| 113 | "What to do to \"exit\" the help buffer. |
| 114 | This is a list |
| 115 | (WINDOW . t) delete the selected window (and possibly its frame, |
| 116 | see `quit-window' and `View-quit'), go to WINDOW. |
| 117 | (WINDOW . quit-window) do quit-window, then select WINDOW. |
| 118 | (WINDOW BUF START POINT) display BUF at START, POINT, then select WINDOW.") |
| 119 | |
| 120 | (defun print-help-return-message (&optional function) |
| 121 | "Display or return message saying how to restore windows after help command. |
| 122 | This function assumes that `standard-output' is the help buffer. |
| 123 | It computes a message, and applies the optional argument FUNCTION to it. |
| 124 | If FUNCTION is nil, it applies `message', thus displaying the message. |
| 125 | In addition, this function sets up `help-return-method', which see, that |
| 126 | specifies what to do when the user exits the help buffer." |
| 127 | (and (not (get-buffer-window standard-output)) |
| 128 | (let ((first-message |
| 129 | (cond ((or |
| 130 | pop-up-frames |
| 131 | (special-display-p (buffer-name standard-output))) |
| 132 | (setq help-return-method (cons (selected-window) t)) |
| 133 | ;; If the help output buffer is a special display buffer, |
| 134 | ;; don't say anything about how to get rid of it. |
| 135 | ;; First of all, the user will do that with the window |
| 136 | ;; manager, not with Emacs. |
| 137 | ;; Secondly, the buffer has not been displayed yet, |
| 138 | ;; so we don't know whether its frame will be selected. |
| 139 | nil) |
| 140 | (display-buffer-reuse-frames |
| 141 | (setq help-return-method (cons (selected-window) |
| 142 | 'quit-window)) |
| 143 | nil) |
| 144 | ((not (one-window-p t)) |
| 145 | (setq help-return-method |
| 146 | (cons (selected-window) 'quit-window)) |
| 147 | "Type \\[display-buffer] RET to restore the other window.") |
| 148 | (pop-up-windows |
| 149 | (setq help-return-method (cons (selected-window) t)) |
| 150 | "Type \\[delete-other-windows] to remove help window.") |
| 151 | (t |
| 152 | (setq help-return-method |
| 153 | (list (selected-window) (window-buffer) |
| 154 | (window-start) (window-point))) |
| 155 | "Type \\[switch-to-buffer] RET to remove help window.")))) |
| 156 | (funcall (or function 'message) |
| 157 | (concat |
| 158 | (if first-message |
| 159 | (substitute-command-keys first-message)) |
| 160 | (if first-message " ") |
| 161 | ;; If the help buffer will go in a separate frame, |
| 162 | ;; it's no use mentioning a command to scroll, so don't. |
| 163 | (if (or pop-up-windows |
| 164 | (special-display-p (buffer-name standard-output))) |
| 165 | nil |
| 166 | (if (same-window-p (buffer-name standard-output)) |
| 167 | ;; Say how to scroll this window. |
| 168 | (substitute-command-keys |
| 169 | "\\[scroll-up] to scroll the help.") |
| 170 | ;; Say how to scroll some other window. |
| 171 | (substitute-command-keys |
| 172 | "\\[scroll-other-window] to scroll the help.")))))))) |
| 173 | |
| 174 | ;; So keyboard macro definitions are documented correctly |
| 175 | (fset 'defining-kbd-macro (symbol-function 'start-kbd-macro)) |
| 176 | |
| 177 | (defalias 'help 'help-for-help-internal) |
| 178 | ;; find-function can find this. |
| 179 | (defalias 'help-for-help 'help-for-help-internal) |
| 180 | ;; It can't find this, but nobody will look. |
| 181 | (make-help-screen help-for-help-internal |
| 182 | "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 ? :" |
| 183 | "You have typed %THIS-KEY%, the help character. Type a Help option: |
| 184 | \(Use SPC or DEL to scroll through this text. Type \\<help-map>\\[help-quit] to exit the Help command.) |
| 185 | |
| 186 | a command-apropos. Type a list of words or a regexp; it shows a list of |
| 187 | commands whose names match. See also the apropos command. |
| 188 | b describe-bindings. Display a table of all key bindings. |
| 189 | c describe-key-briefly. Type a key sequence; |
| 190 | it displays the command name run by that key sequence. |
| 191 | C describe-coding-system. Type the name of the coding system to describe, |
| 192 | or just RET to describe the ones currently in use. |
| 193 | d apropos-documentation. Type a pattern (a list of words or a regexp), and |
| 194 | it shows a list of functions, variables, and other items whose |
| 195 | documentation matches that pattern. See also the apropos command. |
| 196 | e view-echo-area-messages. Go to the buffer that logs echo-area messages. |
| 197 | f describe-function. Type a function name and you see its documentation. |
| 198 | F Info-goto-emacs-command-node. Type a command name; |
| 199 | it goes to the on-line manual's section that describes the command. |
| 200 | h Display the HELLO file which illustrates various scripts. |
| 201 | i info. The Info documentation reader: read on-line manuals. |
| 202 | I describe-input-method. Describe a specific input method (if you type |
| 203 | its name) or the current input method (if you type just RET). |
| 204 | k describe-key. Type a key sequence; |
| 205 | it displays the full documentation for that key sequence. |
| 206 | K Info-goto-emacs-key-command-node. Type a key sequence; |
| 207 | it goes to the on-line manual's section that describes |
| 208 | the command bound to that key. |
| 209 | l view-lossage. Show last 100 characters you typed. |
| 210 | L describe-language-environment. This describes either a |
| 211 | specific language environment (if you type its name) |
| 212 | or the current language environment (if you type just RET). |
| 213 | m describe-mode. Display documentation of current minor modes, |
| 214 | and the current major mode, including their special commands. |
| 215 | n view-emacs-news. Display news of recent Emacs changes. |
| 216 | p finder-by-keyword. Find packages matching a given topic keyword. |
| 217 | r info-emacs-manual. Display the Emacs manual in Info mode. |
| 218 | s describe-syntax. Display contents of syntax table, plus explanations. |
| 219 | S info-lookup-symbol. Type a symbol; it goes to that symbol in the |
| 220 | on-line manual for the programming language used in this buffer. |
| 221 | t help-with-tutorial. Select the Emacs learn-by-doing tutorial. |
| 222 | v describe-variable. Type name of a variable; |
| 223 | it displays the variable's documentation and value. |
| 224 | w where-is. Type a command name; it displays which keystrokes |
| 225 | invoke that command. |
| 226 | . display-local-help. Display any available local help at point |
| 227 | in the echo area. |
| 228 | |
| 229 | C-a Display information about Emacs. |
| 230 | C-c Display Emacs copying permission (GNU General Public License). |
| 231 | C-d Display Emacs ordering information. |
| 232 | C-e Display info about Emacs problems. |
| 233 | C-f Display the Emacs FAQ. |
| 234 | C-m Display how to order printed Emacs manuals. |
| 235 | C-n Display news of recent Emacs changes. |
| 236 | C-p Display information about the GNU project. |
| 237 | C-t Display the Emacs TODO list. |
| 238 | C-w Display information on absence of warranty for GNU Emacs." |
| 239 | help-map) |
| 240 | |
| 241 | \f |
| 242 | |
| 243 | (defun function-called-at-point () |
| 244 | "Return a function around point or else called by the list containing point. |
| 245 | If that doesn't give a function, return nil." |
| 246 | (or (with-syntax-table emacs-lisp-mode-syntax-table |
| 247 | (or (condition-case () |
| 248 | (save-excursion |
| 249 | (or (not (zerop (skip-syntax-backward "_w"))) |
| 250 | (eq (char-syntax (following-char)) ?w) |
| 251 | (eq (char-syntax (following-char)) ?_) |
| 252 | (forward-sexp -1)) |
| 253 | (skip-chars-forward "'") |
| 254 | (let ((obj (read (current-buffer)))) |
| 255 | (and (symbolp obj) (fboundp obj) obj))) |
| 256 | (error nil)) |
| 257 | (condition-case () |
| 258 | (save-excursion |
| 259 | (save-restriction |
| 260 | (narrow-to-region (max (point-min) |
| 261 | (- (point) 1000)) (point-max)) |
| 262 | ;; Move up to surrounding paren, then after the open. |
| 263 | (backward-up-list 1) |
| 264 | (forward-char 1) |
| 265 | ;; If there is space here, this is probably something |
| 266 | ;; other than a real Lisp function call, so ignore it. |
| 267 | (if (looking-at "[ \t]") |
| 268 | (error "Probably not a Lisp function call")) |
| 269 | (let ((obj (read (current-buffer)))) |
| 270 | (and (symbolp obj) (fboundp obj) obj)))) |
| 271 | (error nil)))) |
| 272 | (let* ((str (find-tag-default)) |
| 273 | (sym (if str (intern-soft str)))) |
| 274 | (if (and sym (fboundp sym)) |
| 275 | sym |
| 276 | (save-match-data |
| 277 | (when (and str (string-match "\\`\\W*\\(.*?\\)\\W*\\'" str)) |
| 278 | (setq sym (intern-soft (match-string 1 str))) |
| 279 | (and (fboundp sym) sym))))))) |
| 280 | |
| 281 | \f |
| 282 | ;;; `User' help functions |
| 283 | |
| 284 | (defun describe-distribution () |
| 285 | "Display info on how to obtain the latest version of GNU Emacs." |
| 286 | (interactive) |
| 287 | (view-file (expand-file-name "DISTRIB" data-directory))) |
| 288 | |
| 289 | (defun describe-copying () |
| 290 | "Display info on how you may redistribute copies of GNU Emacs." |
| 291 | (interactive) |
| 292 | (view-file (expand-file-name "COPYING" data-directory)) |
| 293 | (goto-char (point-min))) |
| 294 | |
| 295 | (defun describe-project () |
| 296 | "Display info on the GNU project." |
| 297 | (interactive) |
| 298 | (view-file (expand-file-name "THE-GNU-PROJECT" data-directory)) |
| 299 | (goto-char (point-min))) |
| 300 | |
| 301 | (defun describe-no-warranty () |
| 302 | "Display info on all the kinds of warranty Emacs does NOT have." |
| 303 | (interactive) |
| 304 | (describe-copying) |
| 305 | (let (case-fold-search) |
| 306 | (search-forward "NO WARRANTY") |
| 307 | (recenter 0))) |
| 308 | |
| 309 | (defun describe-prefix-bindings () |
| 310 | "Describe the bindings of the prefix used to reach this command. |
| 311 | The prefix described consists of all but the last event |
| 312 | of the key sequence that ran this command." |
| 313 | (interactive) |
| 314 | (let ((key (this-command-keys))) |
| 315 | (describe-bindings |
| 316 | (if (stringp key) |
| 317 | (substring key 0 (1- (length key))) |
| 318 | (let ((prefix (make-vector (1- (length key)) nil)) |
| 319 | (i 0)) |
| 320 | (while (< i (length prefix)) |
| 321 | (aset prefix i (aref key i)) |
| 322 | (setq i (1+ i))) |
| 323 | prefix))))) |
| 324 | ;; Make C-h after a prefix, when not specifically bound, |
| 325 | ;; run describe-prefix-bindings. |
| 326 | (setq prefix-help-command 'describe-prefix-bindings) |
| 327 | |
| 328 | (defun view-emacs-news (&optional version) |
| 329 | "Display info on recent changes to Emacs. |
| 330 | With argument, display info only for the selected version." |
| 331 | (interactive "P") |
| 332 | (unless version |
| 333 | (setq version emacs-major-version)) |
| 334 | (when (consp version) |
| 335 | (let* ((all-versions |
| 336 | (let (res) |
| 337 | (mapc |
| 338 | (lambda (file) |
| 339 | (with-temp-buffer |
| 340 | (insert-file-contents |
| 341 | (expand-file-name file data-directory)) |
| 342 | (while (re-search-forward |
| 343 | (if (member file '("NEWS.18" "NEWS.1-17")) |
| 344 | "Changes in \\(?:Emacs\\|version\\)?[ \t]*\\([0-9]+\\(?:\\.[0-9]+\\)?\\)" |
| 345 | "^\* [^0-9\n]*\\([0-9]+\\.[0-9]+\\)") nil t) |
| 346 | (setq res (cons (match-string-no-properties 1) res))))) |
| 347 | (cons "NEWS" |
| 348 | (directory-files data-directory nil |
| 349 | "^NEWS\\.[0-9][-0-9]*$" nil))) |
| 350 | (sort (delete-dups res) (lambda (a b) (string< b a))))) |
| 351 | (current (car all-versions))) |
| 352 | (setq version (completing-read |
| 353 | (format "Read NEWS for the version (default %s): " current) |
| 354 | all-versions nil nil nil nil current)) |
| 355 | (if (integerp (string-to-number version)) |
| 356 | (setq version (string-to-number version)) |
| 357 | (unless (or (member version all-versions) |
| 358 | (<= (string-to-number version) (string-to-number current))) |
| 359 | (error "No news about version %s" version))))) |
| 360 | (when (integerp version) |
| 361 | (cond ((<= version 12) |
| 362 | (setq version (format "1.%d" version))) |
| 363 | ((<= version 18) |
| 364 | (setq version (format "%d" version))) |
| 365 | ((> version emacs-major-version) |
| 366 | (error "No news about Emacs %d (yet)" version)))) |
| 367 | (let* ((vn (if (stringp version) |
| 368 | (string-to-number version) |
| 369 | version)) |
| 370 | (file (cond |
| 371 | ((>= vn emacs-major-version) "NEWS") |
| 372 | ((< vn 18) "NEWS.1-17") |
| 373 | (t (format "NEWS.%d" vn)))) |
| 374 | res) |
| 375 | (view-file (expand-file-name file data-directory)) |
| 376 | (widen) |
| 377 | (goto-char (point-min)) |
| 378 | (when (stringp version) |
| 379 | (when (re-search-forward |
| 380 | (concat (if (< vn 19) |
| 381 | "Changes in Emacs[ \t]*" |
| 382 | "^\* [^0-9\n]*") version "$") |
| 383 | nil t) |
| 384 | (beginning-of-line) |
| 385 | (narrow-to-region |
| 386 | (point) |
| 387 | (save-excursion |
| 388 | (while (and (setq res |
| 389 | (re-search-forward |
| 390 | (if (< vn 19) |
| 391 | "Changes in \\(?:Emacs\\|version\\)?[ \t]*\\([0-9]+\\(?:\\.[0-9]+\\)?\\)" |
| 392 | "^\* [^0-9\n]*\\([0-9]+\\.[0-9]+\\)") nil t)) |
| 393 | (equal (match-string-no-properties 1) version))) |
| 394 | (or res (goto-char (point-max))) |
| 395 | (beginning-of-line) |
| 396 | (point))))))) |
| 397 | |
| 398 | |
| 399 | (defun view-todo (&optional arg) |
| 400 | "Display the Emacs TODO list." |
| 401 | (interactive "P") |
| 402 | (view-file (expand-file-name "TODO" data-directory))) |
| 403 | |
| 404 | (defun view-echo-area-messages () |
| 405 | "View the log of recent echo-area messages: the `*Messages*' buffer. |
| 406 | The number of messages retained in that buffer |
| 407 | is specified by the variable `message-log-max'." |
| 408 | (interactive) |
| 409 | (switch-to-buffer (get-buffer-create "*Messages*"))) |
| 410 | |
| 411 | (defun view-order-manuals () |
| 412 | "Display the Emacs ORDERS file." |
| 413 | (interactive) |
| 414 | (view-file (expand-file-name "ORDERS" data-directory)) |
| 415 | (goto-address)) |
| 416 | |
| 417 | (defun view-emacs-FAQ () |
| 418 | "Display the Emacs Frequently Asked Questions (FAQ) file." |
| 419 | (interactive) |
| 420 | ;; (find-file-read-only (expand-file-name "FAQ" data-directory)) |
| 421 | (info "(efaq)")) |
| 422 | |
| 423 | (defun view-emacs-problems () |
| 424 | "Display info on known problems with Emacs and possible workarounds." |
| 425 | (interactive) |
| 426 | (view-file (expand-file-name "PROBLEMS" data-directory))) |
| 427 | |
| 428 | (defun view-lossage () |
| 429 | "Display last 100 input keystrokes. |
| 430 | |
| 431 | To record all your input on a file, use `open-dribble-file'." |
| 432 | (interactive) |
| 433 | (help-setup-xref (list #'view-lossage) (interactive-p)) |
| 434 | (with-output-to-temp-buffer (help-buffer) |
| 435 | (princ (mapconcat (lambda (key) |
| 436 | (if (or (integerp key) (symbolp key) (listp key)) |
| 437 | (single-key-description key) |
| 438 | (prin1-to-string key nil))) |
| 439 | (recent-keys) |
| 440 | " ")) |
| 441 | (with-current-buffer standard-output |
| 442 | (goto-char (point-min)) |
| 443 | (while (progn (move-to-column 50) (not (eobp))) |
| 444 | (when (search-forward " " nil t) |
| 445 | (delete-char -1)) |
| 446 | (insert "\n"))) |
| 447 | (print-help-return-message))) |
| 448 | |
| 449 | \f |
| 450 | ;; Key bindings |
| 451 | |
| 452 | (defun describe-bindings (&optional prefix buffer) |
| 453 | "Show a list of all defined keys, and their definitions. |
| 454 | We put that list in a buffer, and display the buffer. |
| 455 | |
| 456 | The optional argument PREFIX, if non-nil, should be a key sequence; |
| 457 | then we display only bindings that start with that prefix. |
| 458 | The optional argument BUFFER specifies which buffer's bindings |
| 459 | to display (default, the current buffer). BUFFER can be a buffer |
| 460 | or a buffer name." |
| 461 | (interactive) |
| 462 | (or buffer (setq buffer (current-buffer))) |
| 463 | (help-setup-xref (list #'describe-bindings prefix buffer) (interactive-p)) |
| 464 | (with-current-buffer buffer |
| 465 | (describe-bindings-internal nil prefix))) |
| 466 | |
| 467 | ;; This function used to be in keymap.c. |
| 468 | (defun describe-bindings-internal (&optional menus prefix) |
| 469 | "Show a list of all defined keys, and their definitions. |
| 470 | We put that list in a buffer, and display the buffer. |
| 471 | |
| 472 | The optional argument MENUS, if non-nil, says to mention menu bindings. |
| 473 | \(Ordinarily these are omitted from the output.) |
| 474 | The optional argument PREFIX, if non-nil, should be a key sequence; |
| 475 | then we display only bindings that start with that prefix." |
| 476 | (interactive) |
| 477 | (let ((buf (current-buffer))) |
| 478 | (with-output-to-temp-buffer "*Help*" |
| 479 | (with-current-buffer standard-output |
| 480 | (describe-buffer-bindings buf prefix menus))))) |
| 481 | |
| 482 | (defun where-is (definition &optional insert) |
| 483 | "Print message listing key sequences that invoke the command DEFINITION. |
| 484 | Argument is a command definition, usually a symbol with a function definition. |
| 485 | If INSERT (the prefix arg) is non-nil, insert the message in the buffer." |
| 486 | (interactive |
| 487 | (let ((fn (function-called-at-point)) |
| 488 | (enable-recursive-minibuffers t) |
| 489 | val) |
| 490 | (setq val (completing-read |
| 491 | (if fn |
| 492 | (format "Where is command (default %s): " fn) |
| 493 | "Where is command: ") |
| 494 | obarray 'commandp t)) |
| 495 | (list (if (equal val "") fn (intern val)) current-prefix-arg))) |
| 496 | (unless definition (error "No command")) |
| 497 | (let ((func (indirect-function definition)) |
| 498 | (defs nil) |
| 499 | (standard-output (if insert (current-buffer) t))) |
| 500 | ;; In DEFS, find all symbols that are aliases for DEFINITION. |
| 501 | (mapatoms (lambda (symbol) |
| 502 | (and (fboundp symbol) |
| 503 | (not (eq symbol definition)) |
| 504 | (eq func (condition-case () |
| 505 | (indirect-function symbol) |
| 506 | (error symbol))) |
| 507 | (push symbol defs)))) |
| 508 | ;; Look at all the symbols--first DEFINITION, |
| 509 | ;; then its aliases. |
| 510 | (dolist (symbol (cons definition defs)) |
| 511 | (let* ((remapped (command-remapping symbol)) |
| 512 | (keys (where-is-internal |
| 513 | symbol overriding-local-map nil nil remapped)) |
| 514 | (keys (mapconcat 'key-description keys ", ")) |
| 515 | string) |
| 516 | (setq string |
| 517 | (if insert |
| 518 | (if (> (length keys) 0) |
| 519 | (if remapped |
| 520 | (format "%s (%s) (remapped from %s)" |
| 521 | keys remapped symbol) |
| 522 | (format "%s (%s)" keys symbol)) |
| 523 | (format "M-x %s RET" symbol)) |
| 524 | (if (> (length keys) 0) |
| 525 | (if remapped |
| 526 | (format "%s is remapped to %s which is on %s" |
| 527 | symbol remapped keys) |
| 528 | (format "%s is on %s" symbol keys)) |
| 529 | ;; If this is the command the user asked about, |
| 530 | ;; and it is not on any key, say so. |
| 531 | ;; For other symbols, its aliases, say nothing |
| 532 | ;; about them unless they are on keys. |
| 533 | (if (eq symbol definition) |
| 534 | (format "%s is not on any key" symbol))))) |
| 535 | (when string |
| 536 | (unless (eq symbol definition) |
| 537 | (princ ";\n its alias ")) |
| 538 | (princ string))))) |
| 539 | nil) |
| 540 | |
| 541 | (defun help-key-description (key untranslated) |
| 542 | (let ((string (key-description key))) |
| 543 | (if (or (not untranslated) |
| 544 | (and (eq (aref untranslated 0) ?\e) (not (eq (aref key 0) ?\e)))) |
| 545 | string |
| 546 | (let ((otherstring (key-description untranslated))) |
| 547 | (if (equal string otherstring) |
| 548 | string |
| 549 | (format "%s (translated from %s)" string otherstring)))))) |
| 550 | |
| 551 | (defun describe-key-briefly (&optional key insert untranslated) |
| 552 | "Print the name of the function KEY invokes. KEY is a string. |
| 553 | If INSERT (the prefix arg) is non-nil, insert the message in the buffer. |
| 554 | If non-nil, UNTRANSLATED is a vector of the untranslated events. |
| 555 | It can also be a number in which case the untranslated events from |
| 556 | the last key hit are used. |
| 557 | |
| 558 | If KEY is a menu item or a tool-bar button that is disabled, this command |
| 559 | temporarily enables it to allow getting help on disabled items and buttons." |
| 560 | (interactive |
| 561 | (let ((enable-disabled-menus-and-buttons t) |
| 562 | (cursor-in-echo-area t) |
| 563 | saved-yank-menu) |
| 564 | (unwind-protect |
| 565 | (let (key) |
| 566 | ;; If yank-menu is empty, populate it temporarily, so that |
| 567 | ;; "Select and Paste" menu can generate a complete event. |
| 568 | (when (null (cdr yank-menu)) |
| 569 | (setq saved-yank-menu (copy-sequence yank-menu)) |
| 570 | (menu-bar-update-yank-menu "(any string)" nil)) |
| 571 | (setq key (read-key-sequence "Describe key (or click or menu item): ")) |
| 572 | ;; If KEY is a down-event, read and discard the |
| 573 | ;; corresponding up-event. Note that there are also |
| 574 | ;; down-events on scroll bars and mode lines: the actual |
| 575 | ;; event then is in the second element of the vector. |
| 576 | (and (vectorp key) |
| 577 | (let ((last-idx (1- (length key)))) |
| 578 | (and (eventp (aref key last-idx)) |
| 579 | (memq 'down (event-modifiers (aref key last-idx))))) |
| 580 | (read-event)) |
| 581 | (list |
| 582 | key |
| 583 | (if current-prefix-arg (prefix-numeric-value current-prefix-arg)) |
| 584 | 1)) |
| 585 | ;; Put yank-menu back as it was, if we changed it. |
| 586 | (when saved-yank-menu |
| 587 | (setq yank-menu (copy-sequence saved-yank-menu)) |
| 588 | (fset 'yank-menu (cons 'keymap yank-menu)))))) |
| 589 | (if (numberp untranslated) |
| 590 | (setq untranslated (this-single-command-raw-keys))) |
| 591 | (let* ((event (if (and (symbolp (aref key 0)) |
| 592 | (> (length key) 1) |
| 593 | (consp (aref key 1))) |
| 594 | (aref key 1) |
| 595 | (aref key 0))) |
| 596 | (modifiers (event-modifiers event)) |
| 597 | (standard-output (if insert (current-buffer) t)) |
| 598 | (mouse-msg (if (or (memq 'click modifiers) (memq 'down modifiers) |
| 599 | (memq 'drag modifiers)) " at that spot" "")) |
| 600 | (defn (key-binding key t)) |
| 601 | key-desc) |
| 602 | ;; Handle the case where we faked an entry in "Select and Paste" menu. |
| 603 | (if (and (eq defn nil) |
| 604 | (stringp (aref key (1- (length key)))) |
| 605 | (eq (key-binding (substring key 0 -1)) 'yank-menu)) |
| 606 | (setq defn 'menu-bar-select-yank)) |
| 607 | ;; Don't bother user with strings from (e.g.) the select-paste menu. |
| 608 | (if (stringp (aref key (1- (length key)))) |
| 609 | (aset key (1- (length key)) "(any string)")) |
| 610 | (if (and (> (length untranslated) 0) |
| 611 | (stringp (aref untranslated (1- (length untranslated))))) |
| 612 | (aset untranslated (1- (length untranslated)) "(any string)")) |
| 613 | ;; Now describe the key, perhaps as changed. |
| 614 | (setq key-desc (help-key-description key untranslated)) |
| 615 | (if (or (null defn) (integerp defn) (equal defn 'undefined)) |
| 616 | (princ (format "%s%s is undefined" key-desc mouse-msg)) |
| 617 | (princ (format "%s%s runs the command %S" key-desc mouse-msg defn))))) |
| 618 | |
| 619 | (defun describe-key (&optional key untranslated up-event) |
| 620 | "Display documentation of the function invoked by KEY. |
| 621 | KEY can be any kind of a key sequence; it can include keyboard events, |
| 622 | mouse events, and/or menu events. When calling from a program, |
| 623 | pass KEY as a string or a vector. |
| 624 | |
| 625 | If non-nil, UNTRANSLATED is a vector of the corresponding untranslated events. |
| 626 | It can also be a number, in which case the untranslated events from |
| 627 | the last key sequence entered are used. |
| 628 | UP-EVENT is the up-event that was discarded by reading KEY, or nil. |
| 629 | |
| 630 | If KEY is a menu item or a tool-bar button that is disabled, this command |
| 631 | temporarily enables it to allow getting help on disabled items and buttons." |
| 632 | (interactive |
| 633 | (let ((enable-disabled-menus-and-buttons t) |
| 634 | (cursor-in-echo-area t) |
| 635 | saved-yank-menu) |
| 636 | (unwind-protect |
| 637 | (let (key) |
| 638 | ;; If yank-menu is empty, populate it temporarily, so that |
| 639 | ;; "Select and Paste" menu can generate a complete event. |
| 640 | (when (null (cdr yank-menu)) |
| 641 | (setq saved-yank-menu (copy-sequence yank-menu)) |
| 642 | (menu-bar-update-yank-menu "(any string)" nil)) |
| 643 | (setq key (read-key-sequence "Describe key (or click or menu item): ")) |
| 644 | (list |
| 645 | key |
| 646 | (prefix-numeric-value current-prefix-arg) |
| 647 | ;; If KEY is a down-event, read and include the |
| 648 | ;; corresponding up-event. Note that there are also |
| 649 | ;; down-events on scroll bars and mode lines: the actual |
| 650 | ;; event then is in the second element of the vector. |
| 651 | (and (vectorp key) |
| 652 | (let ((last-idx (1- (length key)))) |
| 653 | (and (eventp (aref key last-idx)) |
| 654 | (memq 'down (event-modifiers (aref key last-idx))))) |
| 655 | (or (and (eventp (aref key 0)) |
| 656 | (memq 'down (event-modifiers (aref key 0))) |
| 657 | ;; However, for the C-down-mouse-2 popup |
| 658 | ;; menu, there is no subsequent up-event. In |
| 659 | ;; this case, the up-event is the next |
| 660 | ;; element in the supplied vector. |
| 661 | (= (length key) 1)) |
| 662 | (and (> (length key) 1) |
| 663 | (eventp (aref key 1)) |
| 664 | (memq 'down (event-modifiers (aref key 1))))) |
| 665 | (read-event)))) |
| 666 | ;; Put yank-menu back as it was, if we changed it. |
| 667 | (when saved-yank-menu |
| 668 | (setq yank-menu (copy-sequence saved-yank-menu)) |
| 669 | (fset 'yank-menu (cons 'keymap yank-menu)))))) |
| 670 | (if (numberp untranslated) |
| 671 | (setq untranslated (this-single-command-raw-keys))) |
| 672 | (let* ((event (aref key (if (and (symbolp (aref key 0)) |
| 673 | (> (length key) 1) |
| 674 | (consp (aref key 1))) |
| 675 | 1 |
| 676 | 0))) |
| 677 | (modifiers (event-modifiers event)) |
| 678 | (mouse-msg (if (or (memq 'click modifiers) (memq 'down modifiers) |
| 679 | (memq 'drag modifiers)) " at that spot" "")) |
| 680 | (defn (key-binding key t)) |
| 681 | defn-up defn-up-tricky ev-type |
| 682 | mouse-1-remapped mouse-1-tricky) |
| 683 | |
| 684 | ;; Handle the case where we faked an entry in "Select and Paste" menu. |
| 685 | (when (and (eq defn nil) |
| 686 | (stringp (aref key (1- (length key)))) |
| 687 | (eq (key-binding (substring key 0 -1)) 'yank-menu)) |
| 688 | (setq defn 'menu-bar-select-yank)) |
| 689 | (if (or (null defn) (integerp defn) (equal defn 'undefined)) |
| 690 | (message "%s%s is undefined" |
| 691 | (help-key-description key untranslated) mouse-msg) |
| 692 | (help-setup-xref (list #'describe-function defn) (interactive-p)) |
| 693 | ;; Don't bother user with strings from (e.g.) the select-paste menu. |
| 694 | (when (stringp (aref key (1- (length key)))) |
| 695 | (aset key (1- (length key)) "(any string)")) |
| 696 | (when (and untranslated |
| 697 | (stringp (aref untranslated (1- (length untranslated))))) |
| 698 | (aset untranslated (1- (length untranslated)) |
| 699 | "(any string)")) |
| 700 | ;; Need to do this before erasing *Help* buffer in case event |
| 701 | ;; is a mouse click in an existing *Help* buffer. |
| 702 | (when up-event |
| 703 | (setq ev-type (event-basic-type up-event)) |
| 704 | (let ((sequence (vector up-event))) |
| 705 | (when (and (eq ev-type 'mouse-1) |
| 706 | mouse-1-click-follows-link |
| 707 | (not (eq mouse-1-click-follows-link 'double)) |
| 708 | (setq mouse-1-remapped |
| 709 | (mouse-on-link-p (event-start up-event)))) |
| 710 | (setq mouse-1-tricky (and (integerp mouse-1-click-follows-link) |
| 711 | (> mouse-1-click-follows-link 0))) |
| 712 | (cond ((stringp mouse-1-remapped) |
| 713 | (setq sequence mouse-1-remapped)) |
| 714 | ((vectorp mouse-1-remapped) |
| 715 | (setcar up-event (elt mouse-1-remapped 0))) |
| 716 | (t (setcar up-event 'mouse-2)))) |
| 717 | (setq defn-up (key-binding sequence nil nil (event-start up-event))) |
| 718 | (when mouse-1-tricky |
| 719 | (setq sequence (vector up-event)) |
| 720 | (aset sequence 0 'mouse-1) |
| 721 | (setq defn-up-tricky (key-binding sequence nil nil (event-start up-event)))))) |
| 722 | (with-output-to-temp-buffer (help-buffer) |
| 723 | (princ (help-key-description key untranslated)) |
| 724 | (princ (format "\ |
| 725 | %s runs the command %S |
| 726 | which is " |
| 727 | mouse-msg defn)) |
| 728 | (describe-function-1 defn) |
| 729 | (when up-event |
| 730 | (unless (or (null defn-up) |
| 731 | (integerp defn-up) |
| 732 | (equal defn-up 'undefined)) |
| 733 | (princ (format " |
| 734 | |
| 735 | ----------------- up-event %s---------------- |
| 736 | |
| 737 | <%S>%s%s runs the command %S |
| 738 | which is " |
| 739 | (if mouse-1-tricky "(short click) " "") |
| 740 | ev-type mouse-msg |
| 741 | (if mouse-1-remapped |
| 742 | " is remapped to <mouse-2>\nwhich" "") |
| 743 | defn-up)) |
| 744 | (describe-function-1 defn-up)) |
| 745 | (unless (or (null defn-up-tricky) |
| 746 | (integerp defn-up-tricky) |
| 747 | (eq defn-up-tricky 'undefined)) |
| 748 | (princ (format " |
| 749 | |
| 750 | ----------------- up-event (long click) ---------------- |
| 751 | |
| 752 | Pressing <%S>%s for longer than %d milli-seconds |
| 753 | runs the command %S |
| 754 | which is " |
| 755 | ev-type mouse-msg |
| 756 | mouse-1-click-follows-link |
| 757 | defn-up-tricky)) |
| 758 | (describe-function-1 defn-up-tricky))) |
| 759 | (print-help-return-message))))) |
| 760 | \f |
| 761 | (defun describe-mode (&optional buffer) |
| 762 | "Display documentation of current major mode and minor modes. |
| 763 | A brief summary of the minor modes comes first, followed by the |
| 764 | major mode description. This is followed by detailed |
| 765 | descriptions of the minor modes, each on a separate page. |
| 766 | |
| 767 | For this to work correctly for a minor mode, the mode's indicator |
| 768 | variable \(listed in `minor-mode-alist') must also be a function |
| 769 | whose documentation describes the minor mode." |
| 770 | (interactive "@") |
| 771 | (unless buffer (setq buffer (current-buffer))) |
| 772 | (help-setup-xref (list #'describe-mode buffer) |
| 773 | (interactive-p)) |
| 774 | ;; For the sake of help-do-xref and help-xref-go-back, |
| 775 | ;; don't switch buffers before calling `help-buffer'. |
| 776 | (with-output-to-temp-buffer (help-buffer) |
| 777 | (with-current-buffer buffer |
| 778 | (let (minor-modes) |
| 779 | ;; Older packages do not register in minor-mode-list but only in |
| 780 | ;; minor-mode-alist. |
| 781 | (dolist (x minor-mode-alist) |
| 782 | (setq x (car x)) |
| 783 | (unless (memq x minor-mode-list) |
| 784 | (push x minor-mode-list))) |
| 785 | ;; Find enabled minor mode we will want to mention. |
| 786 | (dolist (mode minor-mode-list) |
| 787 | ;; Document a minor mode if it is listed in minor-mode-alist, |
| 788 | ;; non-nil, and has a function definition. |
| 789 | (let ((fmode (or (get mode :minor-mode-function) mode))) |
| 790 | (and (boundp mode) (symbol-value mode) |
| 791 | (fboundp fmode) |
| 792 | (let ((pretty-minor-mode |
| 793 | (if (string-match "\\(\\(-minor\\)?-mode\\)?\\'" |
| 794 | (symbol-name fmode)) |
| 795 | (capitalize |
| 796 | (substring (symbol-name fmode) |
| 797 | 0 (match-beginning 0))) |
| 798 | fmode))) |
| 799 | (push (list fmode pretty-minor-mode |
| 800 | (format-mode-line (assq mode minor-mode-alist))) |
| 801 | minor-modes))))) |
| 802 | (setq minor-modes |
| 803 | (sort minor-modes |
| 804 | (lambda (a b) (string-lessp (cadr a) (cadr b))))) |
| 805 | (when minor-modes |
| 806 | (princ "Enabled minor modes:\n") |
| 807 | (make-local-variable 'help-button-cache) |
| 808 | (with-current-buffer standard-output |
| 809 | (dolist (mode minor-modes) |
| 810 | (let ((mode-function (nth 0 mode)) |
| 811 | (pretty-minor-mode (nth 1 mode)) |
| 812 | (indicator (nth 2 mode))) |
| 813 | (add-text-properties 0 (length pretty-minor-mode) |
| 814 | '(face bold) pretty-minor-mode) |
| 815 | (save-excursion |
| 816 | (goto-char (point-max)) |
| 817 | (princ "\n\f\n") |
| 818 | (push (point-marker) help-button-cache) |
| 819 | ;; Document the minor modes fully. |
| 820 | (insert pretty-minor-mode) |
| 821 | (princ (format " minor mode (%s):\n" |
| 822 | (if (zerop (length indicator)) |
| 823 | "no indicator" |
| 824 | (format "indicator%s" |
| 825 | indicator)))) |
| 826 | (princ (documentation mode-function))) |
| 827 | (insert-button pretty-minor-mode |
| 828 | 'action (car help-button-cache) |
| 829 | 'follow-link t |
| 830 | 'help-echo "mouse-2, RET: show full information") |
| 831 | (newline))) |
| 832 | (forward-line -1) |
| 833 | (fill-paragraph nil) |
| 834 | (forward-line 1)) |
| 835 | |
| 836 | (princ "\n(Information about these minor modes follows the major mode info.)\n\n")) |
| 837 | ;; Document the major mode. |
| 838 | (let ((mode mode-name)) |
| 839 | (with-current-buffer standard-output |
| 840 | (let ((start (point))) |
| 841 | (insert (format-mode-line mode)) |
| 842 | (add-text-properties start (point) '(face bold))))) |
| 843 | (princ " mode:\n") |
| 844 | (princ (documentation major-mode))) |
| 845 | (print-help-return-message)))) |
| 846 | |
| 847 | |
| 848 | (defun describe-minor-mode (minor-mode) |
| 849 | "Display documentation of a minor mode given as MINOR-MODE. |
| 850 | MINOR-MODE can be a minor mode symbol or a minor mode indicator string |
| 851 | appeared on the mode-line." |
| 852 | (interactive (list (completing-read |
| 853 | "Minor mode: " |
| 854 | (nconc |
| 855 | (describe-minor-mode-completion-table-for-symbol) |
| 856 | (describe-minor-mode-completion-table-for-indicator) |
| 857 | )))) |
| 858 | (if (symbolp minor-mode) |
| 859 | (setq minor-mode (symbol-name minor-mode))) |
| 860 | (let ((symbols (describe-minor-mode-completion-table-for-symbol)) |
| 861 | (indicators (describe-minor-mode-completion-table-for-indicator))) |
| 862 | (cond |
| 863 | ((member minor-mode symbols) |
| 864 | (describe-minor-mode-from-symbol (intern minor-mode))) |
| 865 | ((member minor-mode indicators) |
| 866 | (describe-minor-mode-from-indicator minor-mode)) |
| 867 | (t |
| 868 | (error "No such minor mode: %s" minor-mode))))) |
| 869 | |
| 870 | ;; symbol |
| 871 | (defun describe-minor-mode-completion-table-for-symbol () |
| 872 | ;; In order to list up all minor modes, minor-mode-list |
| 873 | ;; is used here instead of minor-mode-alist. |
| 874 | (delq nil (mapcar 'symbol-name minor-mode-list))) |
| 875 | (defun describe-minor-mode-from-symbol (symbol) |
| 876 | "Display documentation of a minor mode given as a symbol, SYMBOL" |
| 877 | (interactive (list (intern (completing-read |
| 878 | "Minor mode symbol: " |
| 879 | (describe-minor-mode-completion-table-for-symbol))))) |
| 880 | (if (fboundp symbol) |
| 881 | (describe-function symbol) |
| 882 | (describe-variable symbol))) |
| 883 | |
| 884 | ;; indicator |
| 885 | (defun describe-minor-mode-completion-table-for-indicator () |
| 886 | (delq nil |
| 887 | (mapcar (lambda (x) |
| 888 | (let ((i (format-mode-line x))) |
| 889 | ;; remove first space if existed |
| 890 | (cond |
| 891 | ((= 0 (length i)) |
| 892 | nil) |
| 893 | ((eq (aref i 0) ?\s) |
| 894 | (substring i 1)) |
| 895 | (t |
| 896 | i)))) |
| 897 | minor-mode-alist))) |
| 898 | (defun describe-minor-mode-from-indicator (indicator) |
| 899 | "Display documentation of a minor mode specified by INDICATOR. |
| 900 | If you call this function interactively, you can give indicator which |
| 901 | is currently activated with completion." |
| 902 | (interactive (list |
| 903 | (completing-read |
| 904 | "Minor mode indicator: " |
| 905 | (describe-minor-mode-completion-table-for-indicator)))) |
| 906 | (let ((minor-mode (lookup-minor-mode-from-indicator indicator))) |
| 907 | (if minor-mode |
| 908 | (describe-minor-mode-from-symbol minor-mode) |
| 909 | (error "Cannot find minor mode for `%s'" indicator)))) |
| 910 | |
| 911 | (defun lookup-minor-mode-from-indicator (indicator) |
| 912 | "Return a minor mode symbol from its indicator on the modeline." |
| 913 | ;; remove first space if existed |
| 914 | (if (and (< 0 (length indicator)) |
| 915 | (eq (aref indicator 0) ?\s)) |
| 916 | (setq indicator (substring indicator 1))) |
| 917 | (let ((minor-modes minor-mode-alist) |
| 918 | result) |
| 919 | (while minor-modes |
| 920 | (let* ((minor-mode (car (car minor-modes))) |
| 921 | (anindicator (format-mode-line |
| 922 | (car (cdr (car minor-modes)))))) |
| 923 | ;; remove first space if existed |
| 924 | (if (and (stringp anindicator) |
| 925 | (> (length anindicator) 0) |
| 926 | (eq (aref anindicator 0) ?\s)) |
| 927 | (setq anindicator (substring anindicator 1))) |
| 928 | (if (equal indicator anindicator) |
| 929 | (setq result minor-mode |
| 930 | minor-modes nil) |
| 931 | (setq minor-modes (cdr minor-modes))))) |
| 932 | result)) |
| 933 | |
| 934 | \f |
| 935 | ;;; Automatic resizing of temporary buffers. |
| 936 | |
| 937 | (defcustom temp-buffer-max-height (lambda (buffer) (/ (- (frame-height) 2) 2)) |
| 938 | "Maximum height of a window displaying a temporary buffer. |
| 939 | This is effective only when Temp Buffer Resize mode is enabled. |
| 940 | The value is the maximum height (in lines) which `resize-temp-buffer-window' |
| 941 | will give to a window displaying a temporary buffer. |
| 942 | It can also be a function to be called to choose the height for such a buffer. |
| 943 | It gets one argumemt, the buffer, and should return a positive integer." |
| 944 | :type '(choice integer function) |
| 945 | :group 'help |
| 946 | :version "20.4") |
| 947 | |
| 948 | (define-minor-mode temp-buffer-resize-mode |
| 949 | "Toggle the mode which makes windows smaller for temporary buffers. |
| 950 | With prefix argument ARG, turn the resizing of windows displaying temporary |
| 951 | buffers on if ARG is positive or off otherwise. |
| 952 | This makes the window the right height for its contents, but never |
| 953 | more than `temp-buffer-max-height' nor less than `window-min-height'. |
| 954 | This applies to `help', `apropos' and `completion' buffers, and some others." |
| 955 | :global t :group 'help |
| 956 | (if temp-buffer-resize-mode |
| 957 | ;; `help-make-xrefs' may add a `back' button and thus increase the |
| 958 | ;; text size, so `resize-temp-buffer-window' must be run *after* it. |
| 959 | (add-hook 'temp-buffer-show-hook 'resize-temp-buffer-window 'append) |
| 960 | (remove-hook 'temp-buffer-show-hook 'resize-temp-buffer-window))) |
| 961 | |
| 962 | (defun resize-temp-buffer-window () |
| 963 | "Resize the selected window to fit its contents. |
| 964 | Will not make it higher than `temp-buffer-max-height' nor smaller than |
| 965 | `window-min-height'. Do nothing if it is the only window on its frame, if it |
| 966 | is not as wide as the frame or if some of the window's contents are scrolled |
| 967 | out of view." |
| 968 | (unless (or (one-window-p 'nomini) |
| 969 | (not (pos-visible-in-window-p (point-min))) |
| 970 | (not (window-full-width-p))) |
| 971 | (fit-window-to-buffer |
| 972 | (selected-window) |
| 973 | (if (functionp temp-buffer-max-height) |
| 974 | (funcall temp-buffer-max-height (current-buffer)) |
| 975 | temp-buffer-max-height)))) |
| 976 | |
| 977 | \f |
| 978 | (provide 'help) |
| 979 | |
| 980 | ;; arch-tag: cf427352-27e9-49b7-9a6f-741ebab02423 |
| 981 | ;;; help.el ends here |