1 ;;; helper.el --- utility help package supporting help in electric modes
3 ;; Author: K. Shane Hartman
5 ;; Last-Modified: 16 Mar 1991
8 ;; Copyright (C) 1985 Free Software Foundation, Inc.
10 ;; This file is part of GNU Emacs.
12 ;; GNU Emacs is free software; you can redistribute it and/or modify
13 ;; it under the terms of the GNU General Public License as published by
14 ;; the Free Software Foundation; either version 2, or (at your option)
17 ;; GNU Emacs is distributed in the hope that it will be useful,
18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 ;; GNU General Public License for more details.
22 ;; You should have received a copy of the GNU General Public License
23 ;; along with GNU Emacs; see the file COPYING. If not, write to
24 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
28 ; hey, here's a helping hand.
30 ;; Bind this to a string for <blank> in "... Other keys <blank>".
31 ;; Helper-help uses this to construct help string when scrolling.
32 ;; Defaults to "return"
33 (defvar Helper-return-blurb nil
)
35 ;; Keymap implementation doesn't work too well for non-standard loops.
36 ;; But define it anyway for those who can use it. Non-standard loops
37 ;; will probably have to use Helper-help. You can't autoload the
41 (defvar Helper-help-map nil
)
44 (setq Helper-help-map
(make-keymap))
45 ;(fillarray Helper-help-map 'undefined)
46 (define-key Helper-help-map
"m" 'Helper-describe-mode
)
47 (define-key Helper-help-map
"b" 'Helper-describe-bindings
)
48 (define-key Helper-help-map
"c" 'Helper-describe-key-briefly
)
49 (define-key Helper-help-map
"k" 'Helper-describe-key
)
50 ;(define-key Helper-help-map "f" 'Helper-describe-function)
51 ;(define-key Helper-help-map "v" 'Helper-describe-variable)
52 (define-key Helper-help-map
"?" 'Helper-help-options
)
53 (define-key Helper-help-map
(char-to-string help-char
) 'Helper-help-options
)
54 (fset 'Helper-help-map Helper-help-map
))
56 (defun Helper-help-scroller ()
57 (let ((blurb (or (and (boundp 'Helper-return-blurb
)
60 (save-window-excursion
61 (goto-char (window-start (selected-window)))
62 (if (get-buffer-window "*Help*")
63 (pop-to-buffer "*Help*")
64 (switch-to-buffer "*Help*"))
65 (goto-char (point-min))
66 (let ((continue t
) state
)
68 (setq state
(+ (* 2 (if (pos-visible-in-window-p (point-max)) 1 0))
69 (if (pos-visible-in-window-p (point-min)) 1 0)))
72 '("Space forward, Delete back. Other keys %s"
73 "Space scrolls forward. Other keys %s"
74 "Delete scrolls back. Other keys %s"
75 "Type anything to %s"))
77 (setq continue
(read-char))
78 (cond ((and (memq continue
'(?\ ?\C-v
)) (< state
2))
82 ((and (= continue ?
\177) (zerop (% state
2)))
84 (t (setq continue nil
))))))))
86 (defun Helper-help-options ()
87 "Describe help options."
89 (message "c (key briefly), m (mode), k (key), b (bindings)")
90 ;(message "c (key briefly), m (mode), k (key), v (variable), f (function)")
93 (defun Helper-describe-key-briefly (key)
94 "Briefly describe binding of KEY."
95 (interactive "kDescribe key briefly: ")
96 (describe-key-briefly key
)
99 (defun Helper-describe-key (key)
100 "Describe binding of KEY."
101 (interactive "kDescribe key: ")
102 (save-window-excursion (describe-key key
))
103 (Helper-help-scroller))
105 (defun Helper-describe-function ()
106 "Describe a function. Name read interactively."
108 (save-window-excursion (call-interactively 'describe-function
))
109 (Helper-help-scroller))
111 (defun Helper-describe-variable ()
112 "Describe a variable. Name read interactively."
114 (save-window-excursion (call-interactively 'describe-variable
))
115 (Helper-help-scroller))
117 (defun Helper-describe-mode ()
118 "Describe the current mode."
120 (let ((name mode-name
)
121 (documentation (documentation major-mode
)))
123 (set-buffer (get-buffer-create "*Help*"))
125 (insert name
" Mode\n" documentation
)))
126 (Helper-help-scroller))
129 (defun Helper-describe-bindings ()
130 "Describe local key bindings of current mode."
132 (message "Making binding list...")
133 (save-window-excursion (describe-bindings))
134 (Helper-help-scroller))
137 (defun Helper-help ()
138 "Provide help for current mode."
140 (let ((continue t
) c
)
142 (message "Help (Type ? for further options)")
143 (setq c
(char-to-string (downcase (read-char))))
144 (setq c
(lookup-key Helper-help-map c
))
145 (cond ((eq c
'Helper-help-options
)
146 (Helper-help-options))
148 (call-interactively c
)
152 (setq continue nil
))))))
156 ;;; helper.el ends here