X-Git-Url: https://code.delx.au/gnu-emacs/blobdiff_plain/0bb2392728c10748f3376f8cef6d9ca53e29f464..c9586acc9719f5af71c61a24b7c5c40eb1b0905f:/lisp/help.el diff --git a/lisp/help.el b/lisp/help.el index e6496f625d..4219dd8698 100644 --- a/lisp/help.el +++ b/lisp/help.el @@ -1,7 +1,7 @@ ;;; help.el --- help commands for Emacs -;; Copyright (C) 1985-1986, 1993-1994, 1998-2011 -;; Free Software Foundation, Inc. +;; Copyright (C) 1985-1986, 1993-1994, 1998-2013 Free Software +;; Foundation, Inc. ;; Maintainer: FSF ;; Keywords: help, internal @@ -24,7 +24,7 @@ ;;; Commentary: -;; This code implements GNU Emacs' on-line help system, the one invoked by +;; This code implements GNU Emacs's on-line help system, the one invoked by ;; `M-x help-for-help'. ;;; Code: @@ -37,23 +37,13 @@ (add-hook 'temp-buffer-setup-hook 'help-mode-setup) (add-hook 'temp-buffer-show-hook 'help-mode-finish) -;; The variable `help-window' below is used by `help-mode-finish' to -;; communicate the window displaying help (the "help window") to the -;; macro `with-help-window'. The latter sets `help-window' to t before -;; invoking `with-output-to-temp-buffer'. If and only if `help-window' -;; is eq to t, `help-mode-finish' (called by `temp-buffer-setup-hook') -;; sets `help-window' to the window selected by `display-buffer'. -;; Exiting `with-help-window' and calling `help-print-return-message' -;; reset `help-window' to nil. -(defvar help-window nil - "Window chosen for displaying help.") - ;; `help-window-point-marker' is a marker you can move to a valid ;; position of the buffer shown in the help window in order to override ;; the standard positioning mechanism (`point-min') chosen by -;; `with-output-to-temp-buffer'. `with-help-window' has this point -;; nowhere before exiting. Currently used by `view-lossage' to assert -;; that the last keystrokes are always visible. +;; `with-output-to-temp-buffer' and `with-temp-buffer-window'. +;; `with-help-window' has this point nowhere before exiting. Currently +;; used by `view-lossage' to assert that the last keystrokes are always +;; visible. (defvar help-window-point-marker (make-marker) "Marker to override default `window-point' in help windows.") @@ -132,7 +122,7 @@ "What to do to \"exit\" the help buffer. This is a list (WINDOW . t) delete the selected window (and possibly its frame, - see `quit-window' and `View-quit'), go to WINDOW. + see `quit-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.") @@ -157,10 +147,6 @@ specifies what to do when the user exits the help buffer." ;; 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)) @@ -527,7 +513,7 @@ If INSERT (the prefix arg) is non-nil, insert the message in the buffer." (unless definition (error "No command")) (let ((func (indirect-function definition)) (defs nil) - (standard-output (if insert (current-buffer) t))) + (standard-output (if insert (current-buffer) standard-output))) ;; In DEFS, find all symbols that are aliases for DEFINITION. (mapatoms (lambda (symbol) (and (fboundp symbol) @@ -600,6 +586,8 @@ temporarily enables it to allow getting help on disabled items and buttons." (setq saved-yank-menu (copy-sequence yank-menu)) (menu-bar-update-yank-menu "(any string)" nil)) (setq key (read-key-sequence "Describe key (or click or menu item): ")) + ;; Clear the echo area message (Bug#7014). + (message nil) ;; If KEY is a down-event, read and discard the ;; corresponding up-event. Note that there are also ;; down-events on scroll bars and mode lines: the actual @@ -625,7 +613,7 @@ temporarily enables it to allow getting help on disabled items and buttons." (aref key 1) (aref key 0))) (modifiers (event-modifiers event)) - (standard-output (if insert (current-buffer) t)) + (standard-output (if insert (current-buffer) standard-output)) (mouse-msg (if (or (memq 'click modifiers) (memq 'down modifiers) (memq 'drag modifiers)) " at that spot" "")) (defn (key-binding key t)) @@ -795,7 +783,10 @@ 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." +whose documentation describes the minor mode. + +If called from Lisp with a non-nil BUFFER argument, display +documentation for the major and minor modes of that buffer." (interactive "@") (unless buffer (setq buffer (current-buffer))) (help-setup-xref (list #'describe-mode buffer) @@ -951,7 +942,7 @@ is currently activated with completion." (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." + "Return a minor mode symbol from its indicator on the mode line." ;; remove first space if existed (if (and (< 0 (length indicator)) (eq (aref indicator 0) ?\s)) @@ -974,27 +965,38 @@ is currently activated with completion." result)) ;;; Automatic resizing of temporary buffers. -(defcustom temp-buffer-max-height (lambda (buffer) (/ (- (frame-height) 2) 2)) +(defcustom temp-buffer-max-height + (lambda (buffer) + (if (eq (selected-window) (frame-root-window)) + (/ (x-display-pixel-height) (frame-char-height) 2) + (/ (- (frame-height) 2) 2))) "Maximum height of a window displaying a temporary buffer. This is effective only when Temp Buffer Resize mode is enabled. The value is the maximum height (in lines) which `resize-temp-buffer-window' will give to a window displaying a temporary buffer. It can also be a function to be called to -choose the height for such a buffer. It gets one argumemt, the +choose the height for such a buffer. It gets one argument, the buffer, and should return a positive integer. At the time the function is called, the window to be resized is selected." :type '(choice integer function) :group 'help - :version "20.4") + :version "24.3") (define-minor-mode temp-buffer-resize-mode - "Toggle 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. + "Toggle auto-resizing temporary buffer windows (Temp Buffer Resize Mode). +With a prefix argument ARG, enable Temp Buffer Resize mode if ARG +is positive, and disable it otherwise. If called from Lisp, +enable the mode if ARG is omitted or nil. -This mode makes a window the right height for its contents, but -never more than `temp-buffer-max-height' nor less than -`window-min-height'. +When Temp Buffer Resize mode is enabled, the windows in which we +show a temporary buffer are automatically resized in height to +fit the buffer's contents, but never more than +`temp-buffer-max-height' nor less than `window-min-height'. + +A window is resized only if it has been specially created for the +buffer. Windows that have shown another buffer before are not +resized. A frame is resized only if `fit-frame-to-buffer' is +non-nil. This mode is used by `help', `apropos' and `completion' buffers, and some others." @@ -1005,19 +1007,36 @@ and some others." (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 selected window to fit its contents. -Will not make it higher than `temp-buffer-max-height' nor smaller -than `window-min-height'. Do nothing if the selected window is -not vertically combined or some of its contents are scrolled out -of view." - (when (and (pos-visible-in-window-p (point-min)) - (window-iso-combined-p)) - (fit-window-to-buffer - nil - (if (functionp temp-buffer-max-height) - (funcall temp-buffer-max-height (window-buffer)) - temp-buffer-max-height)))) +(defun resize-temp-buffer-window (&optional window) + "Resize WINDOW to fit its contents. +WINDOW can be any live window and defaults to the selected one. + +Do not make WINDOW higher than `temp-buffer-max-height' nor +smaller than `window-min-height'. Do nothing if WINDOW is not +vertically combined, some of its contents are scrolled out of +view, or WINDOW was not created by `display-buffer'." + (setq window (window-normalize-window window t)) + (let ((buffer-name (buffer-name (window-buffer window)))) + (let ((height (if (functionp temp-buffer-max-height) + (with-selected-window window + (funcall temp-buffer-max-height (window-buffer))) + temp-buffer-max-height)) + (quit-cadr (cadr (window-parameter window 'quit-restore)))) + (cond + ;; Resize WINDOW iff it was split off by `display-buffer'. + ((and (eq quit-cadr 'window) + (pos-visible-in-window-p (point-min) window) + (window-combined-p window)) + (fit-window-to-buffer window height)) + ;; Resize FRAME iff it was created by `display-buffer'. + ((and fit-frame-to-buffer + (eq quit-cadr 'frame) + (eq window (frame-root-window window))) + (let ((frame (window-frame window))) + (fit-frame-to-buffer + frame (+ (frame-height frame) + (- (window-total-size window)) + height)))))))) ;;; Help windows. (defcustom help-window-select 'other @@ -1037,6 +1056,16 @@ by `with-help-window'" :group 'help :version "23.1") +(defcustom help-enable-auto-load t + "Whether Help commands can perform autoloading. +If non-nil, whenever \\[describe-function] is called for an +autoloaded function whose docstring contains any key substitution +construct (see `substitute-command-keys'), the library is loaded, +so that the documentation can show the right key bindings." + :type 'boolean + :group 'help + :version "24.3") + (defun help-window-display-message (quit-part window &optional scroll) "Display message telling how to quit and scroll help window. QUIT-PART is a string telling how to quit the help window WINDOW. @@ -1060,14 +1089,13 @@ window." (message "%s" (substitute-command-keys (concat quit-part scroll-part))))) -(defun help-window-setup () +(defun help-window-setup (help-window) "Set up help window for `with-help-window'. -This relies on `display-buffer-window' being correctly set up by -`display-buffer'." - (let* ((help-window (car-safe display-buffer-window)) - (help-buffer (when (window-live-p help-window) +HELP-WINDOW is the window used for displaying the help buffer." + (let* ((help-buffer (when (window-live-p help-window) (window-buffer help-window))) - (help-value (cdr-safe display-buffer-window))) + (help-setup (when (window-live-p help-window) + (car (window-parameter help-window 'quit-restore))))) (when help-buffer ;; Handle `help-window-point-marker'. (when (eq (marker-buffer help-window-point-marker) help-buffer) @@ -1078,6 +1106,7 @@ This relies on `display-buffer-window' being correctly set up by (cond ((or (eq help-window (selected-window)) (and (or (eq help-window-select t) + (eq help-setup 'frame) (and (eq help-window-select 'other) (eq (window-frame help-window) (selected-frame)) (> (length (window-list nil 'no-mini)) 2))) @@ -1085,13 +1114,12 @@ This relies on `display-buffer-window' being correctly set up by ;; The help window is or gets selected ... (help-window-display-message (cond - ((eq help-value 'new-window) + ((eq help-setup 'window) ;; ... and is new, ... - "Type \"q\" to delete this window") - ((eq help-value 'new-frame) - ;; ... is on a new frame ... - "Type \"q\" to delete this frame") - ((eq help-value 'reuse-other-window) + "Type \"q\" to delete help window") + ((eq help-setup 'frame) + "Type \"q\" to delete help frame") + ((eq help-setup 'other) ;; ... or displayed some other buffer before. "Type \"q\" to restore previous buffer")) help-window t)) @@ -1101,15 +1129,22 @@ This relies on `display-buffer-window' being correctly set up by ;; other one is the selected one. (help-window-display-message (cond - ((eq help-value 'new-window) + ((eq help-setup 'window) "Type \\[delete-other-windows] to delete the help window") - ((eq help-value 'reuse-other-window) - "Type \\[switch-to-prev-buffer] RET to restore previous buffer")) + ((eq help-setup 'other) + "Type \"q\" in help window to restore its previous buffer")) help-window 'other)) (t - ;; Not much to say here. + ;; The help window is not selected ... (help-window-display-message - "Type \"q\" in help window to quit" help-window)))))) + (cond + ((eq help-setup 'window) + ;; ... and is new, ... + "Type \"q\" in help window to delete it") + ((eq help-setup 'other) + ;; ... or displayed some other buffer before. + "Type \"q\" in help window to restore previous buffer")) + help-window)))))) ;; `with-help-window' is a wrapper for `with-output-to-temp-buffer' ;; providing the following additional twists: @@ -1128,24 +1163,21 @@ This relies on `display-buffer-window' being correctly set up by (defmacro with-help-window (buffer-name &rest body) "Display buffer with name BUFFER-NAME in a help window evaluating BODY. Select help window if the actual value of the user option -`help-window-select' says so. Return last value in BODY. - -You can specify where and how to show the buffer by binding the -variable `temp-buffer-show-specifiers' to an appropriate value." +`help-window-select' says so. Return last value in BODY." (declare (indent 1) (debug t)) `(progn - ;; Reset `display-buffer-window': `display-buffer' is - ;; supposed to set this to the window displaying the buffer plus - ;; some additional information. - (setq display-buffer-window nil) ;; Make `help-window-point-marker' point nowhere. The only place ;; where this should be set to a buffer position is within BODY. (set-marker help-window-point-marker nil) - (prog1 - ;; Return value returned by `with-output-to-temp-buffer'. - (with-output-to-temp-buffer ,buffer-name - (progn ,@body)) - (when display-buffer-window (help-window-setup))))) + (let* (help-window + (temp-buffer-show-hook + (cons (lambda () (setq help-window (selected-window))) + temp-buffer-show-hook))) + ;; Return value returned by `with-output-to-temp-buffer'. + (prog1 + (with-output-to-temp-buffer ,buffer-name + (progn ,@body)) + (help-window-setup help-window))))) ;; Called from C, on encountering `help-char' when reading a char. ;; Don't print to *Help*; that would clobber Help history.