1 ;;; helper.el --- utility help package supporting help in electric modes
3 ;; Copyright (C) 1985 Free Software Foundation, Inc.
5 ;; Author: K. Shane Hartman
9 ;; This file is part of GNU Emacs.
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 2, or (at your option)
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.
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., 59 Temple Place - Suite 330,
24 ;; Boston, MA 02111-1307, USA.
30 ;; hey, here's a helping hand.
32 ;; Bind this to a string for <blank> in "... Other keys <blank>".
33 ;; Helper-help uses this to construct help string when scrolling.
34 ;; Defaults to "return"
35 (defvar Helper-return-blurb nil
)
37 ;; Keymap implementation doesn't work too well for non-standard loops.
38 ;; But define it anyway for those who can use it. Non-standard loops
39 ;; will probably have to use Helper-help. You can't autoload the
43 (defvar Helper-help-map nil
)
46 (setq Helper-help-map
(make-keymap))
47 ;(fillarray Helper-help-map 'undefined)
48 (define-key Helper-help-map
"m" 'Helper-describe-mode
)
49 (define-key Helper-help-map
"b" 'Helper-describe-bindings
)
50 (define-key Helper-help-map
"c" 'Helper-describe-key-briefly
)
51 (define-key Helper-help-map
"k" 'Helper-describe-key
)
52 ;(define-key Helper-help-map "f" 'Helper-describe-function)
53 ;(define-key Helper-help-map "v" 'Helper-describe-variable)
54 (define-key Helper-help-map
"?" 'Helper-help-options
)
55 (define-key Helper-help-map
(char-to-string help-char
) 'Helper-help-options
)
56 (fset 'Helper-help-map Helper-help-map
))
58 (defun Helper-help-scroller ()
59 (let ((blurb (or (and (boundp 'Helper-return-blurb
)
62 (save-window-excursion
63 (goto-char (window-start (selected-window)))
64 (if (get-buffer-window "*Help*")
65 (pop-to-buffer "*Help*")
66 (switch-to-buffer "*Help*"))
67 (goto-char (point-min))
68 (let ((continue t
) state
)
70 (setq state
(+ (* 2 (if (pos-visible-in-window-p (point-max)) 1 0))
71 (if (pos-visible-in-window-p (point-min)) 1 0)))
74 '("Space forward, Delete back. Other keys %s"
75 "Space scrolls forward. Other keys %s"
76 "Delete scrolls back. Other keys %s"
77 "Type anything to %s"))
79 (setq continue
(read-char))
80 (cond ((and (memq continue
'(?\s ?\C-v
)) (< state
2))
84 ((and (= continue ?
\177) (zerop (% state
2)))
86 (t (setq continue nil
))))))))
88 (defun Helper-help-options ()
89 "Describe help options."
91 (message "c (key briefly), m (mode), k (key), b (bindings)")
92 ;(message "c (key briefly), m (mode), k (key), v (variable), f (function)")
95 (defun Helper-describe-key-briefly (key)
96 "Briefly describe binding of KEY."
97 (interactive "kDescribe key briefly: ")
98 (describe-key-briefly key
)
101 (defun Helper-describe-key (key)
102 "Describe binding of KEY."
103 (interactive "kDescribe key: ")
104 (save-window-excursion (describe-key key
))
105 (Helper-help-scroller))
107 (defun Helper-describe-function ()
108 "Describe a function. Name read interactively."
110 (save-window-excursion (call-interactively 'describe-function
))
111 (Helper-help-scroller))
113 (defun Helper-describe-variable ()
114 "Describe a variable. Name read interactively."
116 (save-window-excursion (call-interactively 'describe-variable
))
117 (Helper-help-scroller))
119 (defun Helper-describe-mode ()
120 "Describe the current mode."
122 (let ((name mode-name
)
123 (documentation (documentation major-mode
)))
125 (set-buffer (get-buffer-create "*Help*"))
126 (setq buffer-read-only nil
)
128 (insert name
" Mode\n" documentation
)
130 (Helper-help-scroller))
133 (defun Helper-describe-bindings ()
134 "Describe local key bindings of current mode."
136 (message "Making binding list...")
137 (save-window-excursion (describe-bindings))
138 (Helper-help-scroller))
141 (defun Helper-help ()
142 "Provide help for current mode."
144 (let ((continue t
) c
)
146 (message "Help (Type ? for further options)")
147 (setq c
(read-key-sequence nil
))
148 (setq c
(lookup-key Helper-help-map c
))
149 (cond ((eq c
'Helper-help-options
)
150 (Helper-help-options))
152 (call-interactively c
)
156 (setq continue nil
))))))
160 ;;; helper.el ends here