mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-12-23 10:34:07 +00:00
9201fa0683
(electric-help-exit): Add doc string. Remove hook before exit.
406 lines
15 KiB
EmacsLisp
406 lines
15 KiB
EmacsLisp
;;; ehelp.el --- bindings for electric-help mode
|
||
|
||
;; Copyright (C) 1986, 1995 Free Software Foundation, Inc.
|
||
|
||
;; Maintainer: FSF
|
||
;; Keywords: help, extensions
|
||
|
||
;; This file is part of GNU Emacs.
|
||
|
||
;; GNU Emacs is free software; you can redistribute it and/or modify
|
||
;; it under the terms of the GNU General Public License as published by
|
||
;; the Free Software Foundation; either version 2, or (at your option)
|
||
;; any later version.
|
||
|
||
;; GNU Emacs is distributed in the hope that it will be useful,
|
||
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
;; GNU General Public License for more details.
|
||
|
||
;; 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.
|
||
|
||
;;; Commentary:
|
||
|
||
;; This package provides a pre-packaged `Electric Help Mode' for
|
||
;; browsing on-line help screens. There is one entry point,
|
||
;; `with-electric-help'; all you have to give it is a no-argument
|
||
;; function that generates the actual text of the help into the current
|
||
;; buffer.
|
||
|
||
;; To make this the default, you must do
|
||
;; (require 'ehelp)
|
||
;; (define-key global-map "\C-h" 'ehelp-command)
|
||
;; (define-key global-map [help] 'ehelp-command)
|
||
;; (define-key global-map [f1] 'ehelp-command)
|
||
|
||
;;; Code:
|
||
|
||
(require 'electric)
|
||
(defvar electric-help-map ()
|
||
"Keymap defining commands available in `electric-help-mode'.")
|
||
|
||
(defvar electric-help-form-to-execute nil)
|
||
|
||
(put 'electric-help-undefined 'suppress-keymap t)
|
||
(if electric-help-map
|
||
()
|
||
(let ((map (make-keymap)))
|
||
;; allow all non-self-inserting keys - search, scroll, etc, but
|
||
;; let M-x and C-x exit ehelp mode and retain buffer:
|
||
(suppress-keymap map)
|
||
(define-key map "\C-u" 'electric-help-undefined)
|
||
(define-key map [?\C-0] 'electric-help-undefined)
|
||
(define-key map [?\C-1] 'electric-help-undefined)
|
||
(define-key map [?\C-2] 'electric-help-undefined)
|
||
(define-key map [?\C-3] 'electric-help-undefined)
|
||
(define-key map [?\C-4] 'electric-help-undefined)
|
||
(define-key map [?\C-5] 'electric-help-undefined)
|
||
(define-key map [?\C-6] 'electric-help-undefined)
|
||
(define-key map [?\C-7] 'electric-help-undefined)
|
||
(define-key map [?\C-8] 'electric-help-undefined)
|
||
(define-key map [?\C-9] 'electric-help-undefined)
|
||
(define-key map (char-to-string help-char) 'electric-help-help)
|
||
(define-key map "?" 'electric-help-help)
|
||
(define-key map " " 'scroll-up)
|
||
(define-key map "\^?" 'scroll-down)
|
||
(define-key map "." 'beginning-of-buffer)
|
||
(define-key map "<" 'beginning-of-buffer)
|
||
(define-key map ">" 'end-of-buffer)
|
||
;(define-key map "\C-g" 'electric-help-exit)
|
||
(define-key map "q" 'electric-help-exit)
|
||
(define-key map "Q" 'electric-help-exit)
|
||
;;a better key than this?
|
||
(define-key map "r" 'electric-help-retain)
|
||
(define-key map "R" 'electric-help-retain)
|
||
(define-key map "\ex" 'electric-help-execute-extended)
|
||
(define-key map "\C-x" 'electric-help-ctrl-x-prefix)
|
||
|
||
(setq electric-help-map map)))
|
||
|
||
(defun electric-help-mode ()
|
||
"`with-electric-help' temporarily places its buffer in this mode.
|
||
\(On exit from `with-electric-help', the buffer is put in `default-major-mode'.)"
|
||
(setq buffer-read-only t)
|
||
(setq mode-name "Help")
|
||
(setq major-mode 'help)
|
||
(setq mode-line-buffer-identification '(" Help: %b"))
|
||
(use-local-map electric-help-map)
|
||
(add-hook 'mouse-leave-buffer-hook 'electric-help-retain)
|
||
(view-mode -1)
|
||
;; this is done below in with-electric-help
|
||
;(run-hooks 'electric-help-mode-hook)
|
||
)
|
||
|
||
;;;###autoload
|
||
(defun with-electric-help (thunk &optional buffer noerase minheight)
|
||
"Pop up an \"electric\" help buffer.
|
||
The arguments are THUNK &optional BUFFER NOERASE MINHEIGHT.
|
||
THUNK is a function of no arguments which is called to initialize the
|
||
contents of BUFFER. BUFFER defaults to `*Help*'. BUFFER will be
|
||
erased before THUNK is called unless NOERASE is non-nil. THUNK will
|
||
be called while BUFFER is current and with `standard-output' bound to
|
||
the buffer specified by BUFFER.
|
||
|
||
If THUNK returns nil, we display BUFFER starting at the top, and
|
||
shrink the window to fit. If THUNK returns non-nil, we don't do those things.
|
||
|
||
After THUNK has been called, this function \"electrically\" pops up a window
|
||
in which BUFFER is displayed and allows the user to scroll through that buffer
|
||
in electric-help-mode. The window's height will be at least MINHEIGHT if
|
||
this value is non-nil.
|
||
|
||
If THUNK returns nil, we display BUFFER starting at the top, and
|
||
shrink the window to fit. If THUNK returns non-nil, we don't do those
|
||
things.
|
||
|
||
When the user exits (with `electric-help-exit', or otherwise) the help
|
||
buffer's window disappears (i.e., we use `save-window-excursion')
|
||
BUFFER is put into `default-major-mode' (or `fundamental-mode') when we exit."
|
||
(setq buffer (get-buffer-create (or buffer "*Help*")))
|
||
(let ((one (one-window-p t))
|
||
(config (current-window-configuration))
|
||
(bury nil)
|
||
(electric-help-form-to-execute nil))
|
||
(unwind-protect
|
||
(save-excursion
|
||
(if one (goto-char (window-start (selected-window))))
|
||
(let ((pop-up-windows t))
|
||
(pop-to-buffer buffer))
|
||
(save-excursion
|
||
(set-buffer buffer)
|
||
(if (and minheight (< (window-height) minheight))
|
||
(enlarge-window (- minheight (window-height))))
|
||
(electric-help-mode)
|
||
(setq buffer-read-only nil)
|
||
(or noerase
|
||
(erase-buffer)))
|
||
(let ((standard-output buffer))
|
||
(if (not (funcall thunk))
|
||
(progn
|
||
(set-buffer buffer)
|
||
(set-buffer-modified-p nil)
|
||
(goto-char (point-min))
|
||
(if one (shrink-window-if-larger-than-buffer (selected-window))))))
|
||
(set-buffer buffer)
|
||
(run-hooks 'electric-help-mode-hook)
|
||
(setq buffer-read-only t)
|
||
(if (eq (car-safe (electric-help-command-loop))
|
||
'retain)
|
||
(setq config (current-window-configuration))
|
||
(setq bury t))
|
||
;; Remove the hook.
|
||
(if (memq 'electric-help-retain mouse-leave-buffer-hook)
|
||
(remove-hook 'mouse-leave-buffer-hook 'electric-help-retain)))
|
||
(message "")
|
||
(set-buffer buffer)
|
||
(setq buffer-read-only nil)
|
||
(condition-case ()
|
||
(funcall (or default-major-mode 'fundamental-mode))
|
||
(error nil))
|
||
(set-window-configuration config)
|
||
(if bury
|
||
(progn
|
||
;;>> Perhaps this shouldn't be done.
|
||
;; so that when we say "Press space to bury" we mean it
|
||
(replace-buffer-in-windows buffer)
|
||
;; must do this outside of save-window-excursion
|
||
(bury-buffer buffer)))
|
||
(eval electric-help-form-to-execute))))
|
||
|
||
(defun electric-help-command-loop ()
|
||
(catch 'exit
|
||
(if (pos-visible-in-window-p (point-max))
|
||
(progn (message "%s" (substitute-command-keys "<<< Press Space to bury the help buffer, Press \\[electric-help-retain] to retain it >>>"))
|
||
(if (equal (setq unread-command-events (list (read-event)))
|
||
'(?\ ))
|
||
(progn (setq unread-command-events nil)
|
||
(throw 'exit t)))))
|
||
(let (up down both neither
|
||
(standard (and (eq (key-binding " ")
|
||
'scroll-up)
|
||
(eq (key-binding "\^?")
|
||
'scroll-down)
|
||
(eq (key-binding "q")
|
||
'electric-help-exit)
|
||
(eq (key-binding "r")
|
||
'electric-help-retain))))
|
||
(Electric-command-loop
|
||
'exit
|
||
(function (lambda ()
|
||
(sit-for 0) ;necessary if last command was end-of-buffer or
|
||
;beginning-of-buffer - otherwise pos-visible-in-window-p
|
||
;will yield a wrong result.
|
||
(let ((min (pos-visible-in-window-p (point-min)))
|
||
(max (pos-visible-in-window-p (point-max))))
|
||
(cond (isearch-mode 'noprompt)
|
||
((and min max)
|
||
(cond (standard "Press q to exit, r to retain ")
|
||
(neither)
|
||
(t (setq neither (substitute-command-keys "Press \\[electric-help-exit] to exit, \\[electric-help-retain] to retain ")))))
|
||
(min
|
||
(cond (standard "Press SPC to scroll, q to exit, r to retain ")
|
||
(up)
|
||
(t (setq up (substitute-command-keys "Press \\[scroll-up] to scroll, \\[electric-help-exit] to exit, \\[electric-help-retain] to retain ")))))
|
||
(max
|
||
(cond (standard "Press DEL to scroll back, q to exit, r to retain ")
|
||
(down)
|
||
(t (setq down (substitute-command-keys "Press \\[scroll-down] to scroll back, \\[electric-help-exit] to exit, \\[electric-help-retain] to retain ")))))
|
||
(t
|
||
(cond (standard "Press SPC to scroll, DEL to scroll back, q to exit, r to retain ")
|
||
(both)
|
||
(t (setq both (substitute-command-keys "Press \\[scroll-up] to scroll, \\[scroll-down] to scroll back, \\[electric-help-exit] to exit, \\[electric-help-retain] to retain ")))))))))
|
||
t))))
|
||
|
||
|
||
|
||
;(defun electric-help-scroll-up (arg)
|
||
; ">>>Doc"
|
||
; (interactive "P")
|
||
; (if (and (null arg) (pos-visible-in-window-p (point-max)))
|
||
; (electric-help-exit)
|
||
; (scroll-up arg)))
|
||
|
||
(defun electric-help-exit ()
|
||
"Exit `electric-help', restoring the previous window/buffer configuration.
|
||
\(The *Help* buffer will be buried.)"
|
||
(interactive)
|
||
;; Make sure that we don't throw twice, even if two events cause
|
||
;; calling this function:
|
||
(if (memq 'electric-help-retain mouse-leave-buffer-hook)
|
||
(progn
|
||
(remove-hook 'mouse-leave-buffer-hook 'electric-help-retain)
|
||
(throw 'exit t))))
|
||
|
||
(defun electric-help-retain ()
|
||
"Exit `electric-help', retaining the current window/buffer configuration.
|
||
\(The *Help* buffer will not be selected, but \\[switch-to-buffer-other-window] RET
|
||
will select it.)"
|
||
(interactive)
|
||
;; Make sure that we don't throw twice, even if two events cause
|
||
;; calling this function:
|
||
(if (memq 'electric-help-retain mouse-leave-buffer-hook)
|
||
(progn
|
||
(remove-hook 'mouse-leave-buffer-hook 'electric-help-retain)
|
||
(throw 'exit '(retain)))))
|
||
|
||
|
||
(defun electric-help-undefined ()
|
||
(interactive)
|
||
(error "%s is undefined -- Press %s to exit"
|
||
(mapconcat 'single-key-description (this-command-keys) " ")
|
||
(if (eq (key-binding "q") 'electric-help-exit)
|
||
"q"
|
||
(substitute-command-keys "\\[electric-help-exit]"))))
|
||
|
||
|
||
;>>> this needs to be hairified (recursive help, anybody?)
|
||
(defun electric-help-help ()
|
||
(interactive)
|
||
(if (and (eq (key-binding "q") 'electric-help-exit)
|
||
(eq (key-binding " ") 'scroll-up)
|
||
(eq (key-binding "\^?") 'scroll-down)
|
||
(eq (key-binding "r") 'electric-help-retain))
|
||
(message "SPC scrolls up, DEL scrolls down, q exits burying help buffer, r exits")
|
||
(message "%s" (substitute-command-keys "\\[scroll-up] scrolls up, \\[scroll-down] scrolls down, \\[electric-help-exit] exits burying help buffer, \\[electric-help-retain] exits")))
|
||
(sit-for 2))
|
||
|
||
|
||
;;;###autoload
|
||
(defun electric-helpify (fun &optional name)
|
||
(let ((name (or name "*Help*")))
|
||
(if (save-window-excursion
|
||
;; kludge-o-rama
|
||
(let* ((p (symbol-function 'print-help-return-message))
|
||
(b (get-buffer name))
|
||
(m (buffer-modified-p b)))
|
||
(and b (not (get-buffer-window b))
|
||
(setq b nil))
|
||
(unwind-protect
|
||
(progn
|
||
(message "%s..." (capitalize (symbol-name fun)))
|
||
;; with-output-to-temp-buffer marks the buffer as unmodified.
|
||
;; kludging excessively and relying on that as some sort
|
||
;; of indication leads to the following abomination...
|
||
;;>> This would be doable without such icky kludges if either
|
||
;;>> (a) there were a function to read the interactive
|
||
;;>> args for a command and return a list of those args.
|
||
;;>> (To which one would then just apply the command)
|
||
;;>> (The only problem with this is that interactive-p
|
||
;;>> would break, but that is such a misfeature in
|
||
;;>> any case that I don't care)
|
||
;;>> It is easy to do this for emacs-lisp functions;
|
||
;;>> the only problem is getting the interactive spec
|
||
;;>> for subrs
|
||
;;>> (b) there were a function which returned a
|
||
;;>> modification-tick for a buffer. One could tell
|
||
;;>> whether a buffer had changed by whether the
|
||
;;>> modification-tick were different.
|
||
;;>> (Presumably there would have to be a way to either
|
||
;;>> restore the tick to some previous value, or to
|
||
;;>> suspend updating of the tick in order to allow
|
||
;;>> things like momentary-string-display)
|
||
(and b
|
||
(save-excursion
|
||
(set-buffer b)
|
||
(set-buffer-modified-p t)))
|
||
(fset 'print-help-return-message 'ignore)
|
||
(call-interactively fun)
|
||
(and (get-buffer name)
|
||
(get-buffer-window (get-buffer name))
|
||
(or (not b)
|
||
(not (eq b (get-buffer name)))
|
||
(not (buffer-modified-p b)))))
|
||
(fset 'print-help-return-message p)
|
||
(and b (buffer-name b)
|
||
(save-excursion
|
||
(set-buffer b)
|
||
(set-buffer-modified-p m))))))
|
||
(with-electric-help 'ignore name t))))
|
||
|
||
|
||
|
||
;; This is to be bound to M-x in ehelp mode. Retains ehelp buffer and then
|
||
;; continues with execute-extended-command.
|
||
(defun electric-help-execute-extended (prefixarg)
|
||
(interactive "p")
|
||
(setq electric-help-form-to-execute '(execute-extended-command nil))
|
||
(electric-help-retain))
|
||
|
||
;; This is to be buond to C-x in ehelp mode. Retains ehelp buffer and then
|
||
;; continues with ctrl-x prefix.
|
||
(defun electric-help-ctrl-x-prefix (prefixarg)
|
||
(interactive "p")
|
||
(setq electric-help-form-to-execute '(progn (message nil) (setq unread-command-char ?\C-x)))
|
||
(electric-help-retain))
|
||
|
||
|
||
(defun electric-describe-key ()
|
||
(interactive)
|
||
(electric-helpify 'describe-key))
|
||
|
||
(defun electric-describe-mode ()
|
||
(interactive)
|
||
(electric-helpify 'describe-mode))
|
||
|
||
(defun electric-view-lossage ()
|
||
(interactive)
|
||
(electric-helpify 'view-lossage))
|
||
|
||
;(defun electric-help-for-help ()
|
||
; "See help-for-help"
|
||
; (interactive)
|
||
; )
|
||
|
||
(defun electric-describe-function ()
|
||
(interactive)
|
||
(electric-helpify 'describe-function))
|
||
|
||
(defun electric-describe-variable ()
|
||
(interactive)
|
||
(electric-helpify 'describe-variable))
|
||
|
||
(defun electric-describe-bindings ()
|
||
(interactive)
|
||
(electric-helpify 'describe-bindings))
|
||
|
||
(defun electric-describe-syntax ()
|
||
(interactive)
|
||
(electric-helpify 'describe-syntax))
|
||
|
||
(defun electric-command-apropos ()
|
||
(interactive)
|
||
(electric-helpify 'command-apropos "*Apropos*"))
|
||
|
||
;(define-key help-map "a" 'electric-command-apropos)
|
||
|
||
(defun electric-apropos ()
|
||
(interactive)
|
||
(electric-helpify 'apropos))
|
||
|
||
|
||
;;;; ehelp-map
|
||
|
||
(defvar ehelp-map ())
|
||
(if ehelp-map
|
||
nil
|
||
(let ((map (copy-keymap help-map)))
|
||
(substitute-key-definition 'apropos 'electric-apropos map)
|
||
(substitute-key-definition 'command-apropos 'electric-command-apropos map)
|
||
(substitute-key-definition 'describe-key 'electric-describe-key map)
|
||
(substitute-key-definition 'describe-mode 'electric-describe-mode map)
|
||
(substitute-key-definition 'view-lossage 'electric-view-lossage map)
|
||
(substitute-key-definition 'describe-function 'electric-describe-function map)
|
||
(substitute-key-definition 'describe-variable 'electric-describe-variable map)
|
||
(substitute-key-definition 'describe-bindings 'electric-describe-bindings map)
|
||
(substitute-key-definition 'describe-syntax 'electric-describe-syntax map)
|
||
|
||
(setq ehelp-map map)
|
||
(fset 'ehelp-command map)))
|
||
|
||
(provide 'ehelp)
|
||
|
||
;;; ehelp.el ends here
|