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1a06eabd | 1 | ;;; helper.el --- utility help package supporting help in electric modes |
a2535589 | 2 | |
ba318903 | 3 | ;; Copyright (C) 1985, 2001-2014 Free Software Foundation, Inc. |
9750e079 | 4 | |
e5167999 | 5 | ;; Author: K. Shane Hartman |
34dc21db | 6 | ;; Maintainer: emacs-devel@gnu.org |
fd7fa35a | 7 | ;; Keywords: help |
bd78fa1d | 8 | ;; Package: emacs |
e5167999 | 9 | |
a2535589 JA |
10 | ;; This file is part of GNU Emacs. |
11 | ||
d6cba7ae | 12 | ;; GNU Emacs is free software: you can redistribute it and/or modify |
a2535589 | 13 | ;; it under the terms of the GNU General Public License as published by |
d6cba7ae GM |
14 | ;; the Free Software Foundation, either version 3 of the License, or |
15 | ;; (at your option) any later version. | |
a2535589 JA |
16 | |
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. | |
21 | ||
22 | ;; You should have received a copy of the GNU General Public License | |
d6cba7ae | 23 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. |
a2535589 | 24 | |
55535639 PJ |
25 | ;;; Commentary: |
26 | ||
e5167999 | 27 | ;;; Code: |
a2535589 | 28 | |
b578f267 | 29 | ;; hey, here's a helping hand. |
a2535589 JA |
30 | |
31 | ;; Bind this to a string for <blank> in "... Other keys <blank>". | |
32 | ;; Helper-help uses this to construct help string when scrolling. | |
33 | ;; Defaults to "return" | |
34 | (defvar Helper-return-blurb nil) | |
35 | ||
36 | ;; Keymap implementation doesn't work too well for non-standard loops. | |
37 | ;; But define it anyway for those who can use it. Non-standard loops | |
38 | ;; will probably have to use Helper-help. You can't autoload the | |
39 | ;; keymap either. | |
40 | ||
41 | ||
42 | (defvar Helper-help-map nil) | |
43 | (if Helper-help-map | |
44 | nil | |
45 | (setq Helper-help-map (make-keymap)) | |
46 | ;(fillarray Helper-help-map 'undefined) | |
47 | (define-key Helper-help-map "m" 'Helper-describe-mode) | |
48 | (define-key Helper-help-map "b" 'Helper-describe-bindings) | |
49 | (define-key Helper-help-map "c" 'Helper-describe-key-briefly) | |
50 | (define-key Helper-help-map "k" 'Helper-describe-key) | |
51 | ;(define-key Helper-help-map "f" 'Helper-describe-function) | |
52 | ;(define-key Helper-help-map "v" 'Helper-describe-variable) | |
53 | (define-key Helper-help-map "?" 'Helper-help-options) | |
54 | (define-key Helper-help-map (char-to-string help-char) 'Helper-help-options) | |
55 | (fset 'Helper-help-map Helper-help-map)) | |
56 | ||
57 | (defun Helper-help-scroller () | |
58 | (let ((blurb (or (and (boundp 'Helper-return-blurb) | |
59 | Helper-return-blurb) | |
60 | "return"))) | |
61 | (save-window-excursion | |
290d5b58 | 62 | (goto-char (window-start)) |
a2535589 JA |
63 | (if (get-buffer-window "*Help*") |
64 | (pop-to-buffer "*Help*") | |
65 | (switch-to-buffer "*Help*")) | |
66 | (goto-char (point-min)) | |
67 | (let ((continue t) state) | |
68 | (while continue | |
69 | (setq state (+ (* 2 (if (pos-visible-in-window-p (point-max)) 1 0)) | |
70 | (if (pos-visible-in-window-p (point-min)) 1 0))) | |
71 | (message | |
72 | (nth state | |
73 | '("Space forward, Delete back. Other keys %s" | |
74 | "Space scrolls forward. Other keys %s" | |
75 | "Delete scrolls back. Other keys %s" | |
76 | "Type anything to %s")) | |
77 | blurb) | |
4b6b279f | 78 | (setq continue (read-event)) |
6cae7b73 | 79 | (cond ((and (memq continue '(?\s ?\C-v)) (< state 2)) |
a2535589 JA |
80 | (scroll-up)) |
81 | ((= continue ?\C-l) | |
82 | (recenter)) | |
83 | ((and (= continue ?\177) (zerop (% state 2))) | |
84 | (scroll-down)) | |
85 | (t (setq continue nil)))))))) | |
86 | ||
87 | (defun Helper-help-options () | |
88 | "Describe help options." | |
89 | (interactive) | |
90 | (message "c (key briefly), m (mode), k (key), b (bindings)") | |
91 | ;(message "c (key briefly), m (mode), k (key), v (variable), f (function)") | |
92 | (sit-for 4)) | |
93 | ||
94 | (defun Helper-describe-key-briefly (key) | |
8a1281b5 | 95 | "Briefly describe binding of KEY." |
a2535589 JA |
96 | (interactive "kDescribe key briefly: ") |
97 | (describe-key-briefly key) | |
98 | (sit-for 4)) | |
99 | ||
100 | (defun Helper-describe-key (key) | |
8a1281b5 | 101 | "Describe binding of KEY." |
a2535589 JA |
102 | (interactive "kDescribe key: ") |
103 | (save-window-excursion (describe-key key)) | |
104 | (Helper-help-scroller)) | |
105 | ||
106 | (defun Helper-describe-function () | |
107 | "Describe a function. Name read interactively." | |
108 | (interactive) | |
109 | (save-window-excursion (call-interactively 'describe-function)) | |
110 | (Helper-help-scroller)) | |
111 | ||
112 | (defun Helper-describe-variable () | |
113 | "Describe a variable. Name read interactively." | |
114 | (interactive) | |
115 | (save-window-excursion (call-interactively 'describe-variable)) | |
116 | (Helper-help-scroller)) | |
117 | ||
118 | (defun Helper-describe-mode () | |
119 | "Describe the current mode." | |
120 | (interactive) | |
48d33090 | 121 | (let ((name (format-mode-line mode-name)) |
a2535589 | 122 | (documentation (documentation major-mode))) |
48d33090 | 123 | (with-current-buffer (get-buffer-create "*Help*") |
36e98846 | 124 | (setq buffer-read-only nil) |
a2535589 | 125 | (erase-buffer) |
eab4afdc KH |
126 | (insert name " Mode\n" documentation) |
127 | (help-mode))) | |
a2535589 JA |
128 | (Helper-help-scroller)) |
129 | ||
f9f9507e | 130 | ;;;###autoload |
a2535589 JA |
131 | (defun Helper-describe-bindings () |
132 | "Describe local key bindings of current mode." | |
133 | (interactive) | |
134 | (message "Making binding list...") | |
135 | (save-window-excursion (describe-bindings)) | |
136 | (Helper-help-scroller)) | |
137 | ||
f9f9507e | 138 | ;;;###autoload |
a2535589 JA |
139 | (defun Helper-help () |
140 | "Provide help for current mode." | |
141 | (interactive) | |
142 | (let ((continue t) c) | |
143 | (while continue | |
144 | (message "Help (Type ? for further options)") | |
3c61e534 | 145 | (setq c (read-key-sequence nil)) |
a2535589 JA |
146 | (setq c (lookup-key Helper-help-map c)) |
147 | (cond ((eq c 'Helper-help-options) | |
148 | (Helper-help-options)) | |
149 | ((commandp c) | |
150 | (call-interactively c) | |
151 | (setq continue nil)) | |
152 | (t | |
153 | (ding) | |
154 | (setq continue nil)))))) | |
155 | ||
1a06eabd ER |
156 | (provide 'helper) |
157 | ||
158 | ;;; helper.el ends here |