;;; help.el --- help commands for Emacs
-;; Copyright (C) 1985, 1986, 1993, 1994 Free Software Foundation, Inc.
+;; Copyright (C) 1985, 1986, 1993, 1994, 1998, 1999, 2000, 2001, 2002,
+;; 2003, 2004, 2005 Free Software Foundation, Inc.
;; Maintainer: FSF
;; Keywords: help, internal
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING. If not, write to the
-;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-;; Boston, MA 02111-1307, USA.
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
;;; Commentary:
;; This code implements GNU Emacs' on-line help system, the one invoked by
-;;`M-x help-for-help'.
+;; `M-x help-for-help'.
;;; Code:
;; or run interpreted, but not when the compiled code is loaded.
(eval-when-compile (require 'help-macro))
+;; This makes `with-output-to-temp-buffer' buffers use `help-mode'.
+(add-hook 'temp-buffer-setup-hook 'help-mode-setup)
+(add-hook 'temp-buffer-show-hook 'help-mode-finish)
+
(defvar help-map (make-sparse-keymap)
"Keymap for characters following the Help key.")
-(defvar help-mode-map (make-sparse-keymap)
- "Keymap for help mode.")
-
(define-key global-map (char-to-string help-char) 'help-command)
(define-key global-map [help] 'help-command)
(define-key global-map [f1] 'help-command)
(define-key help-map (char-to-string help-char) 'help-for-help)
(define-key help-map [help] 'help-for-help)
(define-key help-map [f1] 'help-for-help)
+(define-key help-map "." 'display-local-help)
(define-key help-map "?" 'help-for-help)
(define-key help-map "\C-c" 'describe-copying)
(define-key help-map "\C-d" 'describe-distribution)
-(define-key help-map "\C-w" 'describe-no-warranty)
+(define-key help-map "\C-e" 'view-emacs-problems)
+(define-key help-map "\C-f" 'view-emacs-FAQ)
+(define-key help-map "\C-m" 'view-order-manuals)
+(define-key help-map "\C-n" 'view-emacs-news)
(define-key help-map "\C-p" 'describe-project)
-(define-key help-map "a" 'command-apropos)
+(define-key help-map "\C-t" 'view-todo)
+(define-key help-map "\C-w" 'describe-no-warranty)
+
+;; This does not fit the pattern, but it is natural given the C-\ command.
+(define-key help-map "\C-\\" 'describe-input-method)
+
+(define-key help-map "C" 'describe-coding-system)
+(define-key help-map "F" 'Info-goto-emacs-command-node)
+(define-key help-map "I" 'describe-input-method)
+(define-key help-map "K" 'Info-goto-emacs-key-command-node)
+(define-key help-map "L" 'describe-language-environment)
+(define-key help-map "S" 'info-lookup-symbol)
+
+(define-key help-map "a" 'apropos-command)
(define-key help-map "b" 'describe-bindings)
(define-key help-map "c" 'describe-key-briefly)
-(define-key help-map "k" 'describe-key)
-(define-key help-map "d" 'describe-function)
+(define-key help-map "e" 'view-echo-area-messages)
+
(define-key help-map "f" 'describe-function)
-(define-key help-map "F" 'view-emacs-FAQ)
+(define-key help-map "h" 'view-hello-file)
(define-key help-map "i" 'info)
-(define-key help-map "\C-f" 'Info-goto-emacs-command-node)
-(define-key help-map "\C-k" 'Info-goto-emacs-key-command-node)
+(define-key help-map "4i" 'info-other-window)
+
+(define-key help-map "k" 'describe-key)
(define-key help-map "l" 'view-lossage)
(define-key help-map "m" 'describe-mode)
-(define-key help-map "\C-n" 'view-emacs-news)
(define-key help-map "n" 'view-emacs-news)
(define-key help-map "p" 'finder-by-keyword)
(autoload 'finder-by-keyword "finder"
"Find packages matching a given keyword." t)
+(define-key help-map "r" 'info-emacs-manual)
+
(define-key help-map "s" 'describe-syntax)
(define-key help-map "t" 'help-with-tutorial)
(define-key help-map "q" 'help-quit)
-(defvar help-font-lock-keywords
- (eval-when-compile
- (let ((name-char "[-+a-zA-Z0-9_*]") (sym-char "[-+a-zA-Z0-9_:*]"))
- (list
- ;;
- ;; The symbol itself.
- (list (concat "\\`\\(" name-char "+\\)\\(\\(:\\)\\|\\('\\)\\)")
- '(1 (if (match-beginning 3)
- font-lock-function-name-face
- font-lock-variable-name-face)))
- ;;
- ;; Words inside `' which tend to be symbol names.
- (list (concat "`\\(" sym-char sym-char "+\\)'")
- 1 'font-lock-reference-face t)
- ;;
- ;; CLisp `:' keywords as references.
- (list (concat "\\<:" sym-char "+\\>") 0 'font-lock-reference-face t))))
- "Default expressions to highlight in Help mode.")
-
-(defun help-mode ()
- "Major mode for viewing help text.
-Entry to this mode runs the normal hook `help-mode-hook'.
-Commands:
-\\{help-mode-map}"
- (interactive)
- (kill-all-local-variables)
- (use-local-map help-mode-map)
- (setq mode-name "Help")
- (setq major-mode 'help-mode)
- (make-local-variable 'font-lock-defaults)
- (setq font-lock-defaults '(help-font-lock-keywords))
- (view-mode)
- (run-hooks 'help-mode-hook))
+;; insert-button makes the action nil if it is not store somewhere
+(defvar help-button-cache nil)
+\f
(defun help-quit ()
+ "Just exit from the Help command's command loop."
(interactive)
nil)
-(defun help-with-tutorial ()
- "Select the Emacs learn-by-doing tutorial."
- (interactive)
- (let ((file (expand-file-name "~/TUTORIAL")))
- (delete-other-windows)
- (if (get-file-buffer file)
- (switch-to-buffer (get-file-buffer file))
- (switch-to-buffer (create-file-buffer file))
- (setq buffer-file-name file)
- (setq default-directory (expand-file-name "~/"))
- (setq buffer-auto-save-file-name nil)
- (insert-file-contents (expand-file-name "TUTORIAL" data-directory))
- (goto-char (point-min))
- (search-forward "\n<<")
- (beginning-of-line)
- (delete-region (point) (progn (end-of-line) (point)))
- (let ((n (- (window-height (selected-window))
- (count-lines (point-min) (point))
- 6)))
- (if (< n 12)
- (newline n)
- ;; Some people get confused by the large gap.
- (newline (/ n 2))
- (insert "[Middle of page left blank for didactic purposes. "
- "Text continues below]")
- (newline (- n (/ n 2)))))
- (goto-char (point-min))
- (set-buffer-modified-p nil))))
-
-(defun describe-key-briefly (key)
- "Print the name of the function KEY invokes. KEY is a string."
- (interactive "kDescribe key briefly: ")
- ;; If this key seq ends with a down event, discard the
- ;; following click or drag event. Otherwise that would
- ;; erase the message.
- (let ((type (aref key (1- (length key)))))
- (if (listp type) (setq type (car type)))
- (and (symbolp type)
- (memq 'down (event-modifiers type))
- (read-event)))
- (save-excursion
- (let ((modifiers (event-modifiers (aref key 0)))
- window position)
- ;; For a mouse button event, go to the button it applies to
- ;; to get the right key bindings. And go to the right place
- ;; in case the keymap depends on where you clicked.
- (if (or (memq 'click modifiers) (memq 'down modifiers)
- (memq 'drag modifiers))
- (setq window (posn-window (event-start (aref key 0)))
- position (posn-point (event-start (aref key 0)))))
- (if (windowp window)
- (progn
- (set-buffer (window-buffer window))
- (goto-char position)))
- ;; Ok, now look up the key and name the command.
- (let ((defn (key-binding key)))
- (if (or (null defn) (integerp defn))
- (message "%s is undefined" (key-description key))
- (message (if (windowp window)
- "%s at that spot runs the command %s"
- "%s runs the command %s")
- (key-description key)
- (if (symbolp defn) defn (prin1-to-string defn))))))))
+(defvar help-return-method nil
+ "What to do to \"exit\" the help buffer.
+This is a list
+ (WINDOW . t) delete the selected window, go to WINDOW.
+ (WINDOW . quit-window) do quit-window, then select WINDOW.
+ (WINDOW BUF START POINT) display BUF at START, POINT, then select WINDOW.")
(defun print-help-return-message (&optional function)
"Display or return message saying how to restore windows after help command.
-Computes a message and applies the optional argument FUNCTION to it.
-If FUNCTION is nil, applies `message' to it, thus printing it."
+This function assumes that `standard-output' is the help buffer.
+It computes a message, and applies the optional argument FUNCTION to it.
+If FUNCTION is nil, it applies `message', thus displaying the message."
(and (not (get-buffer-window standard-output))
(let ((first-message
(cond ((special-display-p (buffer-name standard-output))
+ (setq help-return-method (cons (selected-window) t))
;; If the help output buffer is a special display buffer,
;; don't say anything about how to get rid of it.
;; First of all, the user will do that with the window
;; Secondly, the buffer has not been displayed yet,
;; so we don't know whether its frame will be selected.
nil)
+ (display-buffer-reuse-frames
+ (setq help-return-method (cons (selected-window)
+ 'quit-window))
+ nil)
((not (one-window-p t))
+ (setq help-return-method
+ (cons (selected-window) 'quit-window))
"Type \\[switch-to-buffer-other-window] RET to restore the other window.")
(pop-up-windows
+ (setq help-return-method (cons (selected-window) t))
"Type \\[delete-other-windows] to remove help window.")
(t
+ (setq help-return-method
+ (list (selected-window) (window-buffer)
+ (window-start) (window-point)))
"Type \\[switch-to-buffer] RET to remove help window."))))
(funcall (or function 'message)
(concat
(if first-message
- (substitute-command-keys first-message)
- "")
- (if first-message " " "")
+ (substitute-command-keys first-message))
+ (if first-message " ")
;; If the help buffer will go in a separate frame,
;; it's no use mentioning a command to scroll, so don't.
(if (special-display-p (buffer-name standard-output))
(substitute-command-keys
"\\[scroll-other-window] to scroll the help."))))))))
-(defun describe-key (key)
- "Display documentation of the function invoked by KEY. KEY is a string."
- (interactive "kDescribe key: ")
- ;; If this key seq ends with a down event, discard the
- ;; following click or drag event. Otherwise that would
- ;; erase the message.
- (let ((type (aref key (1- (length key)))))
- (if (listp type) (setq type (car type)))
- (and (symbolp type)
- (memq 'down (event-modifiers type))
- (read-event)))
- (save-excursion
- (let ((modifiers (event-modifiers (aref key 0)))
- window position)
- ;; For a mouse button event, go to the button it applies to
- ;; to get the right key bindings. And go to the right place
- ;; in case the keymap depends on where you clicked.
- (if (or (memq 'click modifiers) (memq 'down modifiers)
- (memq 'drag modifiers))
- (setq window (posn-window (event-start (aref key 0)))
- position (posn-point (event-start (aref key 0)))))
- (if (windowp window)
- (progn
- (set-buffer (window-buffer window))
- (goto-char position)))
- (let ((defn (key-binding key)))
- (if (or (null defn) (integerp defn))
- (message "%s is undefined" (key-description key))
- (with-output-to-temp-buffer "*Help*"
- (princ (key-description key))
- (if (windowp window)
- (princ " at that spot"))
- (princ " runs the command ")
- (prin1 defn)
- (princ ":\n")
- (let ((doc (documentation defn)))
- (if doc
- (progn (terpri)
- (princ doc))
- (princ "not documented")))
- (save-excursion
- (set-buffer standard-output)
- (help-mode))
- (print-help-return-message)))))))
-
-(defun describe-mode ()
- "Display documentation of current major mode and minor modes.
-For this to work correctly for a minor mode, the mode's indicator variable
-\(listed in `minor-mode-alist') must also be a function whose documentation
-describes the minor mode."
- (interactive)
- (with-output-to-temp-buffer "*Help*"
- (let ((minor-modes minor-mode-alist)
- (first t)
- (locals (buffer-local-variables)))
- (while minor-modes
- (let* ((minor-mode (car (car minor-modes)))
- (indicator (car (cdr (car minor-modes))))
- (local-binding (assq minor-mode locals)))
- ;; Document a minor mode if it is listed in minor-mode-alist,
- ;; bound locally in this buffer, non-nil, and has a function
- ;; definition.
- (if (and local-binding
- (cdr local-binding)
- (fboundp minor-mode))
- (let ((pretty-minor-mode minor-mode))
- (if (string-match "-mode$" (symbol-name minor-mode))
- (setq pretty-minor-mode
- (capitalize
- (substring (symbol-name minor-mode)
- 0 (match-beginning 0)))))
- (while (and indicator (symbolp indicator))
- (setq indicator (symbol-value indicator)))
- (if first
- (princ "The minor modes are described first,
-followed by the major mode, which is described on the last page.\n\f\n"))
- (setq first nil)
- (princ (format "%s minor mode (%s):\n"
- pretty-minor-mode
- (if indicator
- (format "indicator%s" indicator)
- "no indicator")))
- (princ (documentation minor-mode))
- (princ "\n\f\n"))))
- (setq minor-modes (cdr minor-modes))))
- (princ mode-name)
- (princ " mode:\n")
- (princ (documentation major-mode))
- (save-excursion
- (set-buffer standard-output)
- (help-mode))
- (print-help-return-message)))
-
;; So keyboard macro definitions are documented correctly
(fset 'defining-kbd-macro (symbol-function 'start-kbd-macro))
+(defalias 'help 'help-for-help-internal)
+;; find-function can find this.
+(defalias 'help-for-help 'help-for-help-internal)
+;; It can't find this, but nobody will look.
+(make-help-screen help-for-help-internal
+ "a b c C e f F i I k C-k l L m p s t v w C-c C-d C-f C-n C-p C-t C-w . or ? :"
+ "You have typed %THIS-KEY%, the help character. Type a Help option:
+\(Use SPC or DEL to scroll through this text. Type \\<help-map>\\[help-quit] to exit the Help command.)
+
+a command-apropos. Give a substring, and see a list of commands
+ (functions that are interactively callable) that contain
+ that substring. See also the apropos command.
+b describe-bindings. Display table of all key bindings.
+c describe-key-briefly. Type a command key sequence;
+ it prints the function name that sequence runs.
+C describe-coding-system. This describes either a specific coding system
+ (if you type its name) or the coding systems currently in use
+ (if you type just RET).
+e view-echo-area-messages. Show the buffer where the echo-area messages
+ are stored.
+f describe-function. Type a function name and get its documentation.
+F Info-goto-emacs-command-node. Type a function name;
+ it takes you to the on-line manual's section that describes
+ the command.
+h Display the HELLO file which illustrates various scripts.
+i info. The Info documentation reader: read on-line manuals.
+I describe-input-method. Describe a specific input method (if you type
+ its name) or the current input method (if you type just RET).
+k describe-key. Type a command key sequence;
+ it displays the full documentation for that key sequence.
+K Info-goto-emacs-key-command-node. Type a command key sequence;
+ it takes you to the on-line manual's section that describes
+ the command bound to that key.
+l view-lossage. Show last 100 characters you typed.
+L describe-language-environment. This describes either a
+ specific language environment (if you type its name)
+ or the current language environment (if you type just RET).
+m describe-mode. Display documentation of current minor modes,
+ and the current major mode, including their special commands.
+n view-emacs-news. Display news of recent Emacs changes.
+p finder-by-keyword. Find packages matching a given topic keyword.
+s describe-syntax. Display contents of syntax table, plus explanations.
+S info-lookup-symbol. Display the definition of a specific symbol
+ as found in the manual for the language this buffer is written in.
+t help-with-tutorial. Select the Emacs learn-by-doing tutorial.
+v describe-variable. Type name of a variable;
+ it displays the variable's documentation and value.
+w where-is. Type command name; it prints which keystrokes
+ invoke that command.
+. display-local-help. Display any available local help at point
+ in the echo area.
+
+C-c Display Emacs copying permission (GNU General Public License).
+C-d Display Emacs ordering information.
+C-e Display info about Emacs problems.
+C-f Display the Emacs FAQ.
+C-m Display how to order printed Emacs manuals.
+C-n Display news of recent Emacs changes.
+C-p Display information about the GNU project.
+C-t Display the Emacs TODO list.
+C-w Display information on absence of warranty for GNU Emacs."
+ help-map)
+
+\f
+
+(defun function-called-at-point ()
+ "Return a function around point or else called by the list containing point.
+If that doesn't give a function, return nil."
+ (or (with-syntax-table emacs-lisp-mode-syntax-table
+ (or (condition-case ()
+ (save-excursion
+ (or (not (zerop (skip-syntax-backward "_w")))
+ (eq (char-syntax (following-char)) ?w)
+ (eq (char-syntax (following-char)) ?_)
+ (forward-sexp -1))
+ (skip-chars-forward "'")
+ (let ((obj (read (current-buffer))))
+ (and (symbolp obj) (fboundp obj) obj)))
+ (error nil))
+ (condition-case ()
+ (save-excursion
+ (save-restriction
+ (narrow-to-region (max (point-min)
+ (- (point) 1000)) (point-max))
+ ;; Move up to surrounding paren, then after the open.
+ (backward-up-list 1)
+ (forward-char 1)
+ ;; If there is space here, this is probably something
+ ;; other than a real Lisp function call, so ignore it.
+ (if (looking-at "[ \t]")
+ (error "Probably not a Lisp function call"))
+ (let ((obj (read (current-buffer))))
+ (and (symbolp obj) (fboundp obj) obj))))
+ (error nil))))
+ (let* ((str (find-tag-default))
+ (sym (if str (intern-soft str))))
+ (if (and sym (fboundp sym))
+ sym
+ (save-match-data
+ (when (and str (string-match "\\`\\W*\\(.*?\\)\\W*\\'" str))
+ (setq sym (intern-soft (match-string 1 str)))
+ (and (fboundp sym) sym)))))))
+
+\f
+;;; `User' help functions
+
(defun describe-distribution ()
"Display info on how to obtain the latest version of GNU Emacs."
(interactive)
- (find-file-read-only
- (expand-file-name "DISTRIB" data-directory)))
+ (view-file (expand-file-name "DISTRIB" data-directory)))
(defun describe-copying ()
"Display info on how you may redistribute copies of GNU Emacs."
(interactive)
- (find-file-read-only
- (expand-file-name "COPYING" data-directory))
+ (view-file (expand-file-name "COPYING" data-directory))
(goto-char (point-min)))
(defun describe-project ()
"Display info on the GNU project."
(interactive)
- (find-file-read-only
- (expand-file-name "GNU" data-directory))
+ (view-file (expand-file-name "THE-GNU-PROJECT" data-directory))
(goto-char (point-min)))
(defun describe-no-warranty ()
(aset prefix i (aref key i))
(setq i (1+ i)))
prefix)))))
-;; Make C-h after a prefix, when not specifically bound,
+;; Make C-h after a prefix, when not specifically bound,
;; run describe-prefix-bindings.
(setq prefix-help-command 'describe-prefix-bindings)
-(defun view-emacs-news ()
- "Display info on recent changes to Emacs."
+(defun view-emacs-news (&optional arg)
+ "Display info on recent changes to Emacs.
+With argument, display info only for the selected version."
+ (interactive "P")
+ (if (not arg)
+ (view-file (expand-file-name "NEWS" data-directory))
+ (let* ((map (sort
+ (delete-dups
+ (apply
+ 'nconc
+ (mapcar
+ (lambda (file)
+ (with-temp-buffer
+ (insert-file-contents
+ (expand-file-name file data-directory))
+ (let (res)
+ (while (re-search-forward
+ (if (string-match "^ONEWS\\.[0-9]+$" file)
+ "Changes in \\(?:Emacs\\|version\\)?[ \t]*\\([0-9]+\\(?:\\.[0-9]+\\)?\\)"
+ "^\* [^0-9\n]*\\([0-9]+\\.[0-9]+\\)") nil t)
+ (setq res (cons (list (match-string-no-properties 1)
+ file) res)))
+ res)))
+ (append '("NEWS" "ONEWS")
+ (directory-files data-directory nil
+ "^ONEWS\\.[0-9]+$" nil)))))
+ (lambda (a b)
+ (string< (car b) (car a)))))
+ (current (caar map))
+ (version (completing-read
+ (format "Read NEWS for the version (default %s): " current)
+ (mapcar 'car map) nil nil nil nil current))
+ (file (cadr (assoc version map)))
+ res)
+ (if (not file)
+ (error "No news is good news")
+ (view-file (expand-file-name file data-directory))
+ (widen)
+ (goto-char (point-min))
+ (when (re-search-forward
+ (concat (if (string-match "^ONEWS\\.[0-9]+$" file)
+ "Changes in \\(?:Emacs\\|version\\)?[ \t]*"
+ "^\* [^0-9\n]*") version)
+ nil t)
+ (beginning-of-line)
+ (narrow-to-region
+ (point)
+ (save-excursion
+ (while (and (setq res
+ (re-search-forward
+ (if (string-match "^ONEWS\\.[0-9]+$" file)
+ "Changes in \\(?:Emacs\\|version\\)?[ \t]*\\([0-9]+\\(?:\\.[0-9]+\\)?\\)"
+ "^\* [^0-9\n]*\\([0-9]+\\.[0-9]+\\)") nil t))
+ (equal (match-string-no-properties 1) version)))
+ (or res (goto-char (point-max)))
+ (beginning-of-line)
+ (point))))))))
+
+(defun view-todo (&optional arg)
+ "Display the Emacs TODO list."
+ (interactive "P")
+ (view-file (expand-file-name "TODO" data-directory)))
+
+(defun view-echo-area-messages ()
+ "View the log of recent echo-area messages: the `*Messages*' buffer.
+The number of messages retained in that buffer
+is specified by the variable `message-log-max'."
+ (interactive)
+ (switch-to-buffer (get-buffer-create "*Messages*")))
+
+(defun view-order-manuals ()
+ "Display the Emacs ORDERS file."
(interactive)
- (find-file-read-only (expand-file-name "NEWS" data-directory)))
+ (view-file (expand-file-name "ORDERS" data-directory))
+ (goto-address))
(defun view-emacs-FAQ ()
"Display the Emacs Frequently Asked Questions (FAQ) file."
(interactive)
- (find-file-read-only (expand-file-name "FAQ" data-directory)))
+ ;; (find-file-read-only (expand-file-name "FAQ" data-directory))
+ (info "(efaq)"))
+
+(defun view-emacs-problems ()
+ "Display info on known problems with Emacs and possible workarounds."
+ (interactive)
+ (view-file (expand-file-name "PROBLEMS" data-directory)))
(defun view-lossage ()
- "Display last 100 input keystrokes."
+ "Display last 100 input keystrokes.
+
+To record all your input on a file, use `open-dribble-file'."
(interactive)
- (with-output-to-temp-buffer "*Help*"
- (princ (mapconcat (function (lambda (key)
- (if (or (integerp key)
- (symbolp key)
- (listp key))
- (single-key-description key)
- (prin1-to-string key nil))))
+ (help-setup-xref (list #'view-lossage) (interactive-p))
+ (with-output-to-temp-buffer (help-buffer)
+ (princ (mapconcat (lambda (key)
+ (if (or (integerp key) (symbolp key) (listp key))
+ (single-key-description key)
+ (prin1-to-string key nil)))
(recent-keys)
" "))
- (save-excursion
- (set-buffer standard-output)
+ (with-current-buffer standard-output
(goto-char (point-min))
(while (progn (move-to-column 50) (not (eobp)))
(search-forward " " nil t)
- (insert "\n"))
- (help-mode))
+ (insert "\n")))
(print-help-return-message)))
-(defalias 'help 'help-for-help)
-(make-help-screen help-for-help
- "a b c f C-f i k C-k l m n p s t v w C-c C-d C-n C-w, or ? for more help:"
- "You have typed \\[help-command], the help character. Type a Help option:
-\(Use SPC or DEL to scroll through this text. Type \\<help-map>\\[help-quit] to exit the Help command.)
+\f
+;; Key bindings
-a command-apropos. Give a substring, and see a list of commands
- (functions interactively callable) that contain
- that substring. See also the apropos command.
-b describe-bindings. Display table of all key bindings.
-c describe-key-briefly. Type a command key sequence;
- it prints the function name that sequence runs.
-f describe-function. Type a function name and get documentation of it.
-C-f Info-goto-emacs-command-node. Type a function name;
- it takes you to the Info node for that command.
-F view-emacs-FAQ. Shows emacs frequently asked questions file.
-i info. The info documentation reader.
-k describe-key. Type a command key sequence;
- it displays the full documentation.
-C-k Info-goto-emacs-key-command-node. Type a command key sequence;
- it takes you to the Info node for the command bound to that key.
-l view-lossage. Shows last 100 characters you typed.
-m describe-mode. Print documentation of current major mode,
- which describes the commands peculiar to it.
-n view-emacs-news. Shows emacs news file.
-p finder-by-keyword. Find packages matching a given topic keyword.
-s describe-syntax. Display contents of syntax table, plus explanations
-t help-with-tutorial. Select the Emacs learn-by-doing tutorial.
-v describe-variable. Type name of a variable;
- it displays the variable's documentation and value.
-w where-is. Type command name; it prints which keystrokes
- invoke that command.
-C-c print Emacs copying permission (General Public License).
-C-d print Emacs ordering information.
-C-n print news of recent Emacs changes.
-C-p print information about the GNU project.
-C-w print information on absence of warranty for GNU Emacs."
- help-map)
+(defun describe-bindings (&optional prefix buffer)
+ "Show a list of all defined keys, and their definitions.
+We put that list in a buffer, and display the buffer.
-;; Return a function which is called by the list containing point.
-;; If that gives no function, return a function whose name is around point.
-;; If that doesn't give a function, return nil.
-(defun function-called-at-point ()
- (or (condition-case ()
- (save-excursion
- (save-restriction
- (narrow-to-region (max (point-min) (- (point) 1000)) (point-max))
- (backward-up-list 1)
- (forward-char 1)
- (let (obj)
- (setq obj (read (current-buffer)))
- (and (symbolp obj) (fboundp obj) obj))))
- (error nil))
- (condition-case ()
- (let ((stab (syntax-table)))
- (unwind-protect
- (save-excursion
- (set-syntax-table emacs-lisp-mode-syntax-table)
- (or (not (zerop (skip-syntax-backward "_w")))
- (eq (char-syntax (following-char)) ?w)
- (eq (char-syntax (following-char)) ?_)
- (forward-sexp -1))
- (skip-chars-forward "'")
- (let ((obj (read (current-buffer))))
- (and (symbolp obj) (fboundp obj) obj)))
- (set-syntax-table stab)))
- (error nil))))
-
-(defun describe-function-find-file (function)
- (let ((files load-history)
- file functions)
- (while files
- (if (memq function (cdr (car files)))
- (setq file (car (car files)) files nil))
- (setq files (cdr files)))
- file))
-
-(defun describe-function (function)
- "Display the full documentation of FUNCTION (a symbol)."
+The optional argument PREFIX, if non-nil, should be a key sequence;
+then we display only bindings that start with that prefix.
+The optional argument BUFFER specifies which buffer's bindings
+to display (default, the current buffer). BUFFER can be a buffer
+or a buffer name."
+ (interactive)
+ (or buffer (setq buffer (current-buffer)))
+ (help-setup-xref (list #'describe-bindings prefix buffer) (interactive-p))
+ (with-current-buffer buffer
+ (describe-bindings-internal nil prefix)))
+
+;; This function used to be in keymap.c.
+(defun describe-bindings-internal (&optional menus prefix)
+ "Show a list of all defined keys, and their definitions.
+We put that list in a buffer, and display the buffer.
+
+The optional argument MENUS, if non-nil, says to mention menu bindings.
+\(Ordinarily these are omitted from the output.)
+The optional argument PREFIX, if non-nil, should be a key sequence;
+then we display only bindings that start with that prefix."
+ (interactive)
+ (let ((buf (current-buffer)))
+ (with-output-to-temp-buffer "*Help*"
+ (with-current-buffer standard-output
+ (describe-buffer-bindings buf prefix menus)))))
+
+(defun where-is (definition &optional insert)
+ "Print message listing key sequences that invoke the command DEFINITION.
+Argument is a command definition, usually a symbol with a function definition.
+If INSERT (the prefix arg) is non-nil, insert the message in the buffer."
(interactive
(let ((fn (function-called-at-point))
- (enable-recursive-minibuffers t)
- val)
- (setq val (completing-read (if fn
- (format "Describe function (default %s): " fn)
- "Describe function: ")
- obarray 'fboundp t))
- (list (if (equal val "")
- fn (intern val)))))
- (if function
- (with-output-to-temp-buffer "*Help*"
- (prin1 function)
- (princ ": ")
- (let* ((def (symbol-function function))
- file-name
- (beg (if (commandp def) "an interactive " "a ")))
- (princ (cond ((or (stringp def)
- (vectorp def))
- "a keyboard macro")
- ((subrp def)
- (concat beg "built-in function"))
- ((byte-code-function-p def)
- (concat beg "compiled Lisp function"))
- ((symbolp def)
- (format "alias for `%s'" def))
- ((eq (car-safe def) 'lambda)
- (concat beg "Lisp function"))
- ((eq (car-safe def) 'macro)
- "a Lisp macro")
- ((eq (car-safe def) 'mocklisp)
- "a mocklisp function")
- ((eq (car-safe def) 'autoload)
- (setq file-name (nth 1 def))
- (format "%s autoloaded Lisp %s"
- (if (commandp def) "an interactive" "an")
- (if (nth 4 def) "macro" "function")
- ))
- (t "")))
- (or file-name
- (setq file-name (describe-function-find-file function)))
- (if file-name
- (progn
- (princ " in `")
- ;; We used to add .el to the file name,
- ;; but that's completely wrong when the user used load-file.
- (princ file-name)
- (princ "'")))
- (princ ".")
- (terpri)
- (let ((arglist (cond ((byte-code-function-p def)
- (car (append def nil)))
- ((eq (car-safe def) 'lambda)
- (nth 1 def))
- (t t))))
- (if (listp arglist)
- (progn
- (princ (cons function
- (mapcar (lambda (arg)
- (if (memq arg '(&optional &rest))
- arg
- (intern (upcase (symbol-name arg)))))
- arglist)))
- (terpri))))
- (let ((doc (documentation function)))
- (if doc
- (progn (terpri)
- (princ doc))
- (princ "not documented"))))
- (print-help-return-message)
- (save-excursion
- (set-buffer standard-output)
- (help-mode)
- ;; Return the text we displayed.
- (buffer-string)))
- (message "You didn't specify a function")))
-
-;; We return 0 if we can't find a variable to return.
-(defun variable-at-point ()
- (condition-case ()
- (let ((stab (syntax-table)))
- (unwind-protect
- (save-excursion
- (set-syntax-table emacs-lisp-mode-syntax-table)
- (or (not (zerop (skip-syntax-backward "_w")))
- (eq (char-syntax (following-char)) ?w)
- (eq (char-syntax (following-char)) ?_)
- (forward-sexp -1))
- (skip-chars-forward "'")
- (let ((obj (read (current-buffer))))
- (or (and (symbolp obj) (boundp obj) obj)
- 0)))
- (set-syntax-table stab)))
- (error 0)))
-
-(defun describe-variable (variable)
- "Display the full documentation of VARIABLE (a symbol).
-Returns the documentation as a string, also."
- (interactive
- (let ((v (variable-at-point))
(enable-recursive-minibuffers t)
val)
- (setq val (completing-read (if (symbolp v)
- (format "Describe variable (default %s): " v)
- "Describe variable: ")
- obarray 'boundp t))
- (list (if (equal val "")
- v (intern val)))))
- (if (symbolp variable)
- (let (valvoid)
- (with-output-to-temp-buffer "*Help*"
- (prin1 variable)
- (if (not (boundp variable))
- (progn
- (princ " is void")
- (terpri)
- (setq valvoid t))
- (princ "'s value is ")
- (terpri)
- (pp (symbol-value variable))
- (terpri))
- (if (local-variable-p variable)
- (progn
- (princ (format "Local in buffer %s; " (buffer-name)))
- (if (not (default-boundp variable))
- (princ "globally void")
- (princ "global value is ")
- (terpri)
- (pp (default-value variable)))
- (terpri)))
- (terpri)
- (save-current-buffer
- (set-buffer standard-output)
- (if (> (count-lines (point-min) (point-max)) 10)
- (progn
- (goto-char (point-min))
- (if valvoid
- (forward-line 1)
- (forward-sexp 1)
- (delete-region (point) (progn (end-of-line) (point)))
- (insert "'s value is shown below.\n\n")
- (save-excursion
- (insert "\n\nValue:"))))))
- (princ "Documentation:")
- (terpri)
- (let ((doc (documentation-property variable 'variable-documentation)))
- (princ (or doc "not documented as a variable.")))
- (print-help-return-message)
- (save-excursion
- (set-buffer standard-output)
- (help-mode)
- ;; Return the text we displayed.
- (buffer-string))))
- (message "You did not specify a variable")))
-
-(defun where-is (definition)
- "Print message listing key sequences that invoke specified command.
-Argument is a command definition, usually a symbol with a function definition."
- (interactive
- (let ((fn (function-called-at-point))
- (enable-recursive-minibuffers t)
- val)
- (setq val (completing-read (if fn
- (format "Where is command (default %s): " fn)
- "Where is command: ")
- obarray 'fboundp t))
- (list (if (equal val "")
- fn (intern val)))))
- (let* ((keys (where-is-internal definition overriding-local-map nil nil))
- (keys1 (mapconcat 'key-description keys ", ")))
- (if (> (length keys1) 0)
- (message "%s is on %s" definition keys1)
- (message "%s is not on any key" definition)))
+ (setq val (completing-read
+ (if fn
+ (format "Where is command (default %s): " fn)
+ "Where is command: ")
+ obarray 'commandp t))
+ (list (if (equal val "") fn (intern val)) current-prefix-arg)))
+ (let ((func (indirect-function definition))
+ (defs nil)
+ (standard-output (if insert (current-buffer) t)))
+ ;; In DEFS, find all symbols that are aliases for DEFINITION.
+ (mapatoms (lambda (symbol)
+ (and (fboundp symbol)
+ (not (eq symbol definition))
+ (eq func (condition-case ()
+ (indirect-function symbol)
+ (error symbol)))
+ (push symbol defs))))
+ ;; Look at all the symbols--first DEFINITION,
+ ;; then its aliases.
+ (dolist (symbol (cons definition defs))
+ (let* ((remapped (command-remapping symbol))
+ (keys (where-is-internal
+ symbol overriding-local-map nil nil remapped))
+ (keys (mapconcat 'key-description keys ", "))
+ string)
+ (setq string
+ (if insert
+ (if (> (length keys) 0)
+ (if remapped
+ (format "%s (%s) (remapped from %s)"
+ keys remapped symbol)
+ (format "%s (%s)" keys symbol))
+ (format "M-x %s RET" symbol))
+ (if (> (length keys) 0)
+ (if remapped
+ (format "%s is remapped to %s which is on %s"
+ definition symbol keys)
+ (format "%s is on %s" symbol keys))
+ ;; If this is the command the user asked about,
+ ;; and it is not on any key, say so.
+ ;; For other symbols, its aliases, say nothing
+ ;; about them unless they are on keys.
+ (if (eq symbol definition)
+ (format "%s is not on any key" symbol)))))
+ (when string
+ (unless (eq symbol definition)
+ (princ ";\n its alias "))
+ (princ string)))))
nil)
-(defun locate-library (library &optional nosuffix path interactive-call)
- "Show the precise file name of Emacs library LIBRARY.
-This command searches the directories in `load-path' like `M-x load-library'
-to find the file that `M-x load-library RET LIBRARY RET' would load.
-Optional second arg NOSUFFIX non-nil means don't add suffixes `.elc' or `.el'
-to the specified name LIBRARY.
-
-If the optional third arg PATH is specified, that list of directories
-is used instead of `load-path'."
- (interactive (list (read-string "Locate library: ")
- nil nil
- t))
- (let (result)
- (catch 'answer
- (mapcar
- (lambda (dir)
- (mapcar
- (lambda (suf)
- (let ((try (expand-file-name (concat library suf) dir)))
- (and (file-readable-p try)
- (null (file-directory-p try))
- (progn
- (setq result try)
- (throw 'answer try)))))
- (if nosuffix
- '("")
- (let ((basic '(".elc" ".el" ""))
- (compressed '(".Z" ".gz" "")))
- ;; If autocompression mode is on,
- ;; consider all combinations of library suffixes
- ;; and compression suffixes.
- (if (rassq 'jka-compr-handler file-name-handler-alist)
- (apply 'nconc
- (mapcar (lambda (compelt)
- (mapcar (lambda (baselt)
- (concat baselt compelt))
- basic))
- compressed))
- basic)))))
- (or path load-path)))
- (and interactive-call
- (if result
- (message "Library is file %s" result)
- (message "No library %s in search path" library)))
+(defun string-key-binding (key)
+ "Value is the binding of KEY in a string.
+If KEY is an event on a string, and that string has a `local-map'
+or `keymap' property, return the binding of KEY in the string's keymap."
+ (let* ((defn nil)
+ (start (when (vectorp key)
+ (if (memq (aref key 0)
+ '(mode-line header-line left-margin right-margin))
+ (event-start (aref key 1))
+ (and (consp (aref key 0))
+ (event-start (aref key 0))))))
+ (string-info (and (consp start) (nth 4 start))))
+ (when string-info
+ (let* ((string (car string-info))
+ (pos (cdr string-info))
+ (local-map (and (>= pos 0)
+ (< pos (length string))
+ (or (get-text-property pos 'local-map string)
+ (get-text-property pos 'keymap string)))))
+ (setq defn (and local-map (lookup-key local-map key)))))
+ defn))
+
+(defun help-key-description (key untranslated)
+ (let ((string (key-description key)))
+ (if (or (not untranslated)
+ (and (eq (aref untranslated 0) ?\e) (not (eq (aref key 0) ?\e))))
+ string
+ (let ((otherstring (key-description untranslated)))
+ (if (equal string otherstring)
+ string
+ (format "%s (translated from %s)" string otherstring))))))
+
+(defun describe-key-briefly (key &optional insert untranslated)
+ "Print the name of the function KEY invokes. KEY is a string.
+If INSERT (the prefix arg) is non-nil, insert the message in the buffer.
+If non-nil UNTRANSLATED is a vector of the untranslated events.
+It can also be a number in which case the untranslated events from
+the last key hit are used."
+ (interactive "kDescribe key briefly: \nP\np")
+ (if (numberp untranslated)
+ (setq untranslated (this-single-command-raw-keys)))
+ (save-excursion
+ (let ((modifiers (event-modifiers (aref key 0)))
+ (standard-output (if insert (current-buffer) t))
+ window position)
+ ;; For a mouse button event, go to the button it applies to
+ ;; to get the right key bindings. And go to the right place
+ ;; in case the keymap depends on where you clicked.
+ (if (or (memq 'click modifiers) (memq 'down modifiers)
+ (memq 'drag modifiers))
+ (setq window (posn-window (event-start (aref key 0)))
+ position (posn-point (event-start (aref key 0)))))
+ (if (windowp window)
+ (progn
+ (set-buffer (window-buffer window))
+ (goto-char position)))
+ ;; Ok, now look up the key and name the command.
+ (let ((defn (or (string-key-binding key)
+ (key-binding key)))
+ key-desc)
+ ;; Don't bother user with strings from (e.g.) the select-paste menu.
+ (if (stringp (aref key (1- (length key))))
+ (aset key (1- (length key)) "(any string)"))
+ (if (and (> (length untranslated) 0)
+ (stringp (aref untranslated (1- (length untranslated)))))
+ (aset untranslated (1- (length untranslated))
+ "(any string)"))
+ ;; Now describe the key, perhaps as changed.
+ (setq key-desc (help-key-description key untranslated))
+ (if (or (null defn) (integerp defn) (equal defn 'undefined))
+ (princ (format "%s is undefined" key-desc))
+ (princ (format (if (windowp window)
+ "%s at that spot runs the command %s"
+ "%s runs the command %s")
+ key-desc
+ (if (symbolp defn) defn (prin1-to-string defn)))))))))
+
+(defun describe-key (key &optional untranslated up-event)
+ "Display documentation of the function invoked by KEY.
+KEY should be a key sequence--when calling from a program,
+pass a string or a vector.
+If non-nil UNTRANSLATED is a vector of the untranslated events.
+It can also be a number in which case the untranslated events from
+the last key hit are used."
+ ;; UP-EVENT is the up-event that was discarded by reading KEY, or nil.
+ (interactive "kDescribe key: \np\nU")
+ (if (numberp untranslated)
+ (setq untranslated (this-single-command-raw-keys)))
+ (save-excursion
+ (let ((modifiers (event-modifiers (aref key 0)))
+ window position)
+ ;; For a mouse button event, go to the button it applies to
+ ;; to get the right key bindings. And go to the right place
+ ;; in case the keymap depends on where you clicked.
+ (if (or (memq 'click modifiers) (memq 'down modifiers)
+ (memq 'drag modifiers))
+ (setq window (posn-window (event-start (aref key 0)))
+ position (posn-point (event-start (aref key 0)))))
+ (when (windowp window)
+ (set-buffer (window-buffer window))
+ (goto-char position))
+ (let ((defn (or (string-key-binding key) (key-binding key))))
+ (if (or (null defn) (integerp defn) (equal defn 'undefined))
+ (message "%s is undefined" (help-key-description key untranslated))
+ (help-setup-xref (list #'describe-function defn) (interactive-p))
+ ;; Don't bother user with strings from (e.g.) the select-paste menu.
+ (if (stringp (aref key (1- (length key))))
+ (aset key (1- (length key)) "(any string)"))
+ (if (and untranslated
+ (stringp (aref untranslated (1- (length untranslated)))))
+ (aset untranslated (1- (length untranslated))
+ "(any string)"))
+ (with-output-to-temp-buffer (help-buffer)
+ (princ (help-key-description key untranslated))
+ (if (windowp window)
+ (princ " at that spot"))
+ (princ " runs the command ")
+ (prin1 defn)
+ (princ "\n which is ")
+ (describe-function-1 defn)
+ (when up-event
+ (let ((ev (aref up-event 0))
+ (descr (key-description up-event))
+ (hdr "\n\n-------------- up event ---------------\n\n")
+ defn
+ mouse-1-tricky mouse-1-remapped)
+ (when (and (consp ev)
+ (eq (car ev) 'mouse-1)
+ (windowp window)
+ mouse-1-click-follows-link
+ (not (eq mouse-1-click-follows-link 'double))
+ (with-current-buffer (window-buffer window)
+ (mouse-on-link-p (posn-point (event-start ev)))))
+ (setq mouse-1-tricky (integerp mouse-1-click-follows-link)
+ mouse-1-remapped (or (not mouse-1-tricky)
+ (> mouse-1-click-follows-link 0)))
+ (if mouse-1-remapped
+ (setcar ev 'mouse-2)))
+ (setq defn (or (string-key-binding up-event) (key-binding up-event)))
+ (unless (or (null defn) (integerp defn) (equal defn 'undefined))
+ (princ (if mouse-1-tricky
+ "\n\n----------------- up-event (short click) ----------------\n\n"
+ hdr))
+ (setq hdr nil)
+ (princ descr)
+ (if (windowp window)
+ (princ " at that spot"))
+ (if mouse-1-remapped
+ (princ " is remapped to <mouse-2>\n which" ))
+ (princ " runs the command ")
+ (prin1 defn)
+ (princ "\n which is ")
+ (describe-function-1 defn))
+ (when mouse-1-tricky
+ (setcar ev
+ (if (> mouse-1-click-follows-link 0) 'mouse-1 'mouse-2))
+ (setq defn (or (string-key-binding up-event) (key-binding up-event)))
+ (unless (or (null defn) (integerp defn) (equal defn 'undefined))
+ (princ (or hdr
+ "\n\n----------------- up-event (long click) ----------------\n\n"))
+ (princ "Pressing ")
+ (princ descr)
+ (if (windowp window)
+ (princ " at that spot"))
+ (princ (format " for longer than %d milli-seconds\n"
+ (abs mouse-1-click-follows-link)))
+ (if (not mouse-1-remapped)
+ (princ " remaps it to <mouse-2> which" ))
+ (princ " runs the command ")
+ (prin1 defn)
+ (princ "\n which is ")
+ (describe-function-1 defn)))))
+ (print-help-return-message)))))))
+
+\f
+(defun describe-mode (&optional buffer)
+ "Display documentation of current major mode and minor modes.
+A brief summary of the minor modes comes first, followed by the
+major mode description. This is followed by detailed
+descriptions of the minor modes, each on a separate page.
+
+For this to work correctly for a minor mode, the mode's indicator
+variable \(listed in `minor-mode-alist') must also be a function
+whose documentation describes the minor mode."
+ (interactive)
+ (unless buffer (setq buffer (current-buffer)))
+ (help-setup-xref (list #'describe-mode buffer)
+ (interactive-p))
+ ;; For the sake of help-do-xref and help-xref-go-back,
+ ;; don't switch buffers before calling `help-buffer'.
+ (with-output-to-temp-buffer (help-buffer)
+ (with-current-buffer buffer
+ (let (minor-modes)
+ ;; Older packages do not register in minor-mode-list but only in
+ ;; minor-mode-alist.
+ (dolist (x minor-mode-alist)
+ (setq x (car x))
+ (unless (memq x minor-mode-list)
+ (push x minor-mode-list)))
+ ;; Find enabled minor mode we will want to mention.
+ (dolist (mode minor-mode-list)
+ ;; Document a minor mode if it is listed in minor-mode-alist,
+ ;; non-nil, and has a function definition.
+ (let ((fmode (or (get mode :minor-mode-function) mode)))
+ (and (boundp mode) (symbol-value mode)
+ (fboundp fmode)
+ (let ((pretty-minor-mode
+ (if (string-match "\\(\\(-minor\\)?-mode\\)?\\'"
+ (symbol-name fmode))
+ (capitalize
+ (substring (symbol-name fmode)
+ 0 (match-beginning 0)))
+ fmode)))
+ (push (list fmode pretty-minor-mode
+ (format-mode-line (assq mode minor-mode-alist)))
+ minor-modes)))))
+ (setq minor-modes
+ (sort minor-modes
+ (lambda (a b) (string-lessp (cadr a) (cadr b)))))
+ (when minor-modes
+ (princ "Summary of minor modes:\n")
+ (make-local-variable 'help-button-cache)
+ (with-current-buffer standard-output
+ (dolist (mode minor-modes)
+ (let ((mode-function (nth 0 mode))
+ (pretty-minor-mode (nth 1 mode))
+ (indicator (nth 2 mode)))
+ (setq indicator (if (zerop (length indicator))
+ "no indicator"
+ (format "indicator%s" indicator)))
+ (add-text-properties 0 (length pretty-minor-mode)
+ '(face bold) pretty-minor-mode)
+ (save-excursion
+ (goto-char (point-max))
+ (princ "\n\f\n")
+ (push (point-marker) help-button-cache)
+ ;; Document the minor modes fully.
+ (insert pretty-minor-mode)
+ (princ (format " minor mode (%s):\n" indicator))
+ (princ (documentation mode-function)))
+ (princ " ")
+ (insert-button pretty-minor-mode
+ 'action (car help-button-cache)
+ 'follow-link t
+ 'help-echo "mouse-2, RET: show full information")
+ (princ (format " minor mode (%s):\n" indicator)))))
+ (princ "\n(Full information about these minor modes
+follows the description of the major mode.)\n\n"))
+ ;; Document the major mode.
+ (let ((mode mode-name))
+ (with-current-buffer standard-output
+ (insert mode)
+ (add-text-properties (- (point) (length mode)) (point) '(face bold))))
+ (princ " mode:\n")
+ (princ (documentation major-mode)))
+ (print-help-return-message))))
+
+
+(defun describe-minor-mode (minor-mode)
+ "Display documentation of a minor mode given as MINOR-MODE.
+MINOR-MODE can be a minor mode symbol or a minor mode indicator string
+appeared on the mode-line."
+ (interactive (list (completing-read
+ "Minor mode: "
+ (nconc
+ (describe-minor-mode-completion-table-for-symbol)
+ (describe-minor-mode-completion-table-for-indicator)
+ ))))
+ (if (symbolp minor-mode)
+ (setq minor-mode (symbol-name minor-mode)))
+ (let ((symbols (describe-minor-mode-completion-table-for-symbol))
+ (indicators (describe-minor-mode-completion-table-for-indicator)))
+ (cond
+ ((member minor-mode symbols)
+ (describe-minor-mode-from-symbol (intern minor-mode)))
+ ((member minor-mode indicators)
+ (describe-minor-mode-from-indicator minor-mode))
+ (t
+ (error "No such minor mode: %s" minor-mode)))))
+
+;; symbol
+(defun describe-minor-mode-completion-table-for-symbol ()
+ ;; In order to list up all minor modes, minor-mode-list
+ ;; is used here instead of minor-mode-alist.
+ (delq nil (mapcar 'symbol-name minor-mode-list)))
+(defun describe-minor-mode-from-symbol (symbol)
+ "Display documentation of a minor mode given as a symbol, SYMBOL"
+ (interactive (list (intern (completing-read
+ "Minor mode symbol: "
+ (describe-minor-mode-completion-table-for-symbol)))))
+ (if (fboundp symbol)
+ (describe-function symbol)
+ (describe-variable symbol)))
+
+;; indicator
+(defun describe-minor-mode-completion-table-for-indicator ()
+ (delq nil
+ (mapcar (lambda (x)
+ (let ((i (format-mode-line x)))
+ ;; remove first space if existed
+ (cond
+ ((= 0 (length i))
+ nil)
+ ((eq (aref i 0) ?\ )
+ (substring i 1))
+ (t
+ i))))
+ minor-mode-alist)))
+(defun describe-minor-mode-from-indicator (indicator)
+ "Display documentation of a minor mode specified by INDICATOR.
+If you call this function interactively, you can give indicator which
+is currently activated with completion."
+ (interactive (list
+ (completing-read
+ "Minor mode indicator: "
+ (describe-minor-mode-completion-table-for-indicator))))
+ (let ((minor-mode (lookup-minor-mode-from-indicator indicator)))
+ (if minor-mode
+ (describe-minor-mode-from-symbol minor-mode)
+ (error "Cannot find minor mode for `%s'" indicator))))
+
+(defun lookup-minor-mode-from-indicator (indicator)
+ "Return a minor mode symbol from its indicator on the modeline."
+ ;; remove first space if existed
+ (if (and (< 0 (length indicator))
+ (eq (aref indicator 0) ?\ ))
+ (setq indicator (substring indicator 1)))
+ (let ((minor-modes minor-mode-alist)
+ result)
+ (while minor-modes
+ (let* ((minor-mode (car (car minor-modes)))
+ (anindicator (format-mode-line
+ (car (cdr (car minor-modes))))))
+ ;; remove first space if existed
+ (if (and (stringp anindicator)
+ (> (length anindicator) 0)
+ (eq (aref anindicator 0) ?\ ))
+ (setq anindicator (substring anindicator 1)))
+ (if (equal indicator anindicator)
+ (setq result minor-mode
+ minor-modes nil)
+ (setq minor-modes (cdr minor-modes)))))
result))
+\f
+;;; Automatic resizing of temporary buffers.
+
+(defcustom temp-buffer-max-height (lambda (buffer) (/ (- (frame-height) 2) 2))
+ "*Maximum height of a window displaying a temporary buffer.
+This is the maximum height (in text lines) which `resize-temp-buffer-window'
+will give to a window displaying a temporary buffer.
+It can also be a function which will be called with the object corresponding
+to the buffer to be displayed as argument and should return an integer
+positive number."
+ :type '(choice integer function)
+ :group 'help
+ :version "20.4")
+
+(define-minor-mode temp-buffer-resize-mode
+ "Toggle the mode which makes windows smaller for temporary buffers.
+With prefix argument ARG, turn the resizing of windows displaying temporary
+buffers on if ARG is positive or off otherwise.
+This makes the window the right height for its contents, but never
+more than `temp-buffer-max-height' nor less than `window-min-height'.
+This applies to `help', `apropos' and `completion' buffers, and some others."
+ :global t :group 'help
+ (if temp-buffer-resize-mode
+ ;; `help-make-xrefs' may add a `back' button and thus increase the
+ ;; text size, so `resize-temp-buffer-window' must be run *after* it.
+ (add-hook 'temp-buffer-show-hook 'resize-temp-buffer-window 'append)
+ (remove-hook 'temp-buffer-show-hook 'resize-temp-buffer-window)))
+
+(defun resize-temp-buffer-window ()
+ "Resize the current window to fit its contents.
+Will not make it higher than `temp-buffer-max-height' nor smaller than
+`window-min-height'. Do nothing if it is the only window on its frame, if it
+is not as wide as the frame or if some of the window's contents are scrolled
+out of view."
+ (unless (or (one-window-p 'nomini)
+ (not (pos-visible-in-window-p (point-min)))
+ (/= (frame-width) (window-width)))
+ (fit-window-to-buffer
+ (selected-window)
+ (if (functionp temp-buffer-max-height)
+ (funcall temp-buffer-max-height (current-buffer))
+ temp-buffer-max-height))))
+
+;; Provide this for the sake of define-minor-mode which generates
+;; defcustoms which require 'help'.
+(provide 'help)
+
+;; arch-tag: cf427352-27e9-49b7-9a6f-741ebab02423
;;; help.el ends here