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1a06eabd | 1 | ;;; helper.el --- utility help package supporting help in electric modes |
a2535589 | 2 | |
9750e079 ER |
3 | ;; Copyright (C) 1985 Free Software Foundation, Inc. |
4 | ||
e5167999 ER |
5 | ;; Author: K. Shane Hartman |
6 | ;; Maintainer: FSF | |
fd7fa35a | 7 | ;; Keywords: help |
e5167999 | 8 | |
a2535589 JA |
9 | ;; This file is part of GNU Emacs. |
10 | ||
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 | |
e5167999 | 13 | ;; the Free Software Foundation; either version 2, or (at your option) |
a2535589 JA |
14 | ;; any later version. |
15 | ||
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. | |
20 | ||
21 | ;; You should have received a copy of the GNU General Public License | |
b578f267 EN |
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. | |
a2535589 | 25 | |
55535639 PJ |
26 | ;;; Commentary: |
27 | ||
e5167999 | 28 | ;;; Code: |
a2535589 | 29 | |
b578f267 | 30 | ;; hey, here's a helping hand. |
a2535589 JA |
31 | |
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) | |
36 | ||
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 | |
40 | ;; keymap either. | |
41 | ||
42 | ||
43 | (defvar Helper-help-map nil) | |
44 | (if Helper-help-map | |
45 | 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)) | |
57 | ||
58 | (defun Helper-help-scroller () | |
59 | (let ((blurb (or (and (boundp 'Helper-return-blurb) | |
60 | Helper-return-blurb) | |
61 | "return"))) | |
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) | |
69 | (while continue | |
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))) | |
72 | (message | |
73 | (nth state | |
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")) | |
78 | blurb) | |
79 | (setq continue (read-char)) | |
6cae7b73 | 80 | (cond ((and (memq continue '(?\s ?\C-v)) (< state 2)) |
a2535589 JA |
81 | (scroll-up)) |
82 | ((= continue ?\C-l) | |
83 | (recenter)) | |
84 | ((and (= continue ?\177) (zerop (% state 2))) | |
85 | (scroll-down)) | |
86 | (t (setq continue nil)))))))) | |
87 | ||
88 | (defun Helper-help-options () | |
89 | "Describe help options." | |
90 | (interactive) | |
91 | (message "c (key briefly), m (mode), k (key), b (bindings)") | |
92 | ;(message "c (key briefly), m (mode), k (key), v (variable), f (function)") | |
93 | (sit-for 4)) | |
94 | ||
95 | (defun Helper-describe-key-briefly (key) | |
8a1281b5 | 96 | "Briefly describe binding of KEY." |
a2535589 JA |
97 | (interactive "kDescribe key briefly: ") |
98 | (describe-key-briefly key) | |
99 | (sit-for 4)) | |
100 | ||
101 | (defun Helper-describe-key (key) | |
8a1281b5 | 102 | "Describe binding of KEY." |
a2535589 JA |
103 | (interactive "kDescribe key: ") |
104 | (save-window-excursion (describe-key key)) | |
105 | (Helper-help-scroller)) | |
106 | ||
107 | (defun Helper-describe-function () | |
108 | "Describe a function. Name read interactively." | |
109 | (interactive) | |
110 | (save-window-excursion (call-interactively 'describe-function)) | |
111 | (Helper-help-scroller)) | |
112 | ||
113 | (defun Helper-describe-variable () | |
114 | "Describe a variable. Name read interactively." | |
115 | (interactive) | |
116 | (save-window-excursion (call-interactively 'describe-variable)) | |
117 | (Helper-help-scroller)) | |
118 | ||
119 | (defun Helper-describe-mode () | |
120 | "Describe the current mode." | |
121 | (interactive) | |
122 | (let ((name mode-name) | |
123 | (documentation (documentation major-mode))) | |
124 | (save-excursion | |
125 | (set-buffer (get-buffer-create "*Help*")) | |
36e98846 | 126 | (setq buffer-read-only nil) |
a2535589 | 127 | (erase-buffer) |
eab4afdc KH |
128 | (insert name " Mode\n" documentation) |
129 | (help-mode))) | |
a2535589 JA |
130 | (Helper-help-scroller)) |
131 | ||
f9f9507e | 132 | ;;;###autoload |
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133 | (defun Helper-describe-bindings () |
134 | "Describe local key bindings of current mode." | |
135 | (interactive) | |
136 | (message "Making binding list...") | |
137 | (save-window-excursion (describe-bindings)) | |
138 | (Helper-help-scroller)) | |
139 | ||
f9f9507e | 140 | ;;;###autoload |
a2535589 JA |
141 | (defun Helper-help () |
142 | "Provide help for current mode." | |
143 | (interactive) | |
144 | (let ((continue t) c) | |
145 | (while continue | |
146 | (message "Help (Type ? for further options)") | |
3c61e534 | 147 | (setq c (read-key-sequence nil)) |
a2535589 JA |
148 | (setq c (lookup-key Helper-help-map c)) |
149 | (cond ((eq c 'Helper-help-options) | |
150 | (Helper-help-options)) | |
151 | ((commandp c) | |
152 | (call-interactively c) | |
153 | (setq continue nil)) | |
154 | (t | |
155 | (ding) | |
156 | (setq continue nil)))))) | |
157 | ||
1a06eabd ER |
158 | (provide 'helper) |
159 | ||
160 | ;;; helper.el ends here |