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c0274f38 ER |
1 | ;;; ehelp.el --- bindings for electric-help mode |
2 | ||
732be465 | 3 | ;; Copyright (C) 1986, 1995 Free Software Foundation, Inc. |
3a801d0c | 4 | |
e5167999 | 5 | ;; Maintainer: FSF |
fd7fa35a | 6 | ;; Keywords: help, extensions |
e5167999 | 7 | |
a2535589 JA |
8 | ;; This file is part of GNU Emacs. |
9 | ||
10 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
11 | ;; it under the terms of the GNU General Public License as published by | |
e5167999 | 12 | ;; the Free Software Foundation; either version 2, or (at your option) |
a2535589 JA |
13 | ;; any later version. |
14 | ||
15 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
16 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | ;; GNU General Public License for more details. | |
19 | ||
20 | ;; You should have received a copy of the GNU General Public License | |
b578f267 EN |
21 | ;; along with GNU Emacs; see the file COPYING. If not, write to the |
22 | ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
23 | ;; Boston, MA 02111-1307, USA. | |
a2535589 | 24 | |
e41b2db1 ER |
25 | ;;; Commentary: |
26 | ||
27 | ;; This package provides a pre-packaged `Electric Help Mode' for | |
28 | ;; browsing on-line help screens. There is one entry point, | |
9dd2b34e | 29 | ;; `with-electric-help'; all you have to give it is a no-argument |
1b3250ab | 30 | ;; function that generates the actual text of the help into the current |
e41b2db1 ER |
31 | ;; buffer. |
32 | ||
bbe2ecf6 RS |
33 | ;; To make this the default, you must do |
34 | ;; (require 'ehelp) | |
35 | ;; (define-key global-map "\C-h" 'ehelp-command) | |
36 | ;; (define-key global-map [help] 'ehelp-command) | |
37 | ;; (define-key global-map [f1] 'ehelp-command) | |
38 | ||
e5167999 ER |
39 | ;;; Code: |
40 | ||
a2535589 | 41 | (require 'electric) |
a2535589 | 42 | (defvar electric-help-map () |
d5b9d1d8 | 43 | "Keymap defining commands available in `electric-help-mode'.") |
a2535589 | 44 | |
db30b383 RS |
45 | (defvar electric-help-form-to-execute nil) |
46 | ||
a2535589 JA |
47 | (put 'electric-help-undefined 'suppress-keymap t) |
48 | (if electric-help-map | |
49 | () | |
50 | (let ((map (make-keymap))) | |
f98e758c RS |
51 | ;; allow all non-self-inserting keys - search, scroll, etc, but |
52 | ;; let M-x and C-x exit ehelp mode and retain buffer: | |
e27ef4db | 53 | (suppress-keymap map) |
f98e758c RS |
54 | (define-key map "\C-u" 'electric-help-undefined) |
55 | (define-key map [?\C-0] 'electric-help-undefined) | |
56 | (define-key map [?\C-1] 'electric-help-undefined) | |
57 | (define-key map [?\C-2] 'electric-help-undefined) | |
58 | (define-key map [?\C-3] 'electric-help-undefined) | |
59 | (define-key map [?\C-4] 'electric-help-undefined) | |
60 | (define-key map [?\C-5] 'electric-help-undefined) | |
61 | (define-key map [?\C-6] 'electric-help-undefined) | |
62 | (define-key map [?\C-7] 'electric-help-undefined) | |
63 | (define-key map [?\C-8] 'electric-help-undefined) | |
64 | (define-key map [?\C-9] 'electric-help-undefined) | |
a2535589 JA |
65 | (define-key map (char-to-string help-char) 'electric-help-help) |
66 | (define-key map "?" 'electric-help-help) | |
67 | (define-key map " " 'scroll-up) | |
68 | (define-key map "\^?" 'scroll-down) | |
69 | (define-key map "." 'beginning-of-buffer) | |
70 | (define-key map "<" 'beginning-of-buffer) | |
71 | (define-key map ">" 'end-of-buffer) | |
72 | ;(define-key map "\C-g" 'electric-help-exit) | |
73 | (define-key map "q" 'electric-help-exit) | |
74 | (define-key map "Q" 'electric-help-exit) | |
75 | ;;a better key than this? | |
76 | (define-key map "r" 'electric-help-retain) | |
e27ef4db | 77 | (define-key map "R" 'electric-help-retain) |
f98e758c RS |
78 | (define-key map "\ex" 'electric-help-execute-extended) |
79 | (define-key map "\C-x" 'electric-help-ctrl-x-prefix) | |
a2535589 JA |
80 | |
81 | (setq electric-help-map map))) | |
f98e758c | 82 | |
a2535589 | 83 | (defun electric-help-mode () |
d5b9d1d8 JB |
84 | "`with-electric-help' temporarily places its buffer in this mode. |
85 | \(On exit from `with-electric-help', the buffer is put in `default-major-mode'.)" | |
a2535589 JA |
86 | (setq buffer-read-only t) |
87 | (setq mode-name "Help") | |
88 | (setq major-mode 'help) | |
89 | (setq mode-line-buffer-identification '(" Help: %b")) | |
90 | (use-local-map electric-help-map) | |
2e8174d2 | 91 | (add-hook 'mouse-leave-buffer-hook 'electric-help-retain) |
db30b383 | 92 | (view-mode -1) |
a2535589 JA |
93 | ;; this is done below in with-electric-help |
94 | ;(run-hooks 'electric-help-mode-hook) | |
95 | ) | |
96 | ||
9dd2b34e | 97 | ;;;###autoload |
483a5ec0 | 98 | (defun with-electric-help (thunk &optional buffer noerase minheight) |
bbe2ecf6 | 99 | "Pop up an \"electric\" help buffer. |
f98e758c RS |
100 | The arguments are THUNK &optional BUFFER NOERASE MINHEIGHT. |
101 | THUNK is a function of no arguments which is called to initialize the | |
102 | contents of BUFFER. BUFFER defaults to `*Help*'. BUFFER will be | |
103 | erased before THUNK is called unless NOERASE is non-nil. THUNK will | |
104 | be called while BUFFER is current and with `standard-output' bound to | |
bbe2ecf6 RS |
105 | the buffer specified by BUFFER. |
106 | ||
107 | If THUNK returns nil, we display BUFFER starting at the top, and | |
108 | shrink the window to fit. If THUNK returns non-nil, we don't do those things. | |
a2535589 JA |
109 | |
110 | After THUNK has been called, this function \"electrically\" pops up a window | |
111 | in which BUFFER is displayed and allows the user to scroll through that buffer | |
f98e758c RS |
112 | in electric-help-mode. The window's height will be at least MINHEIGHT if |
113 | this value is non-nil. | |
114 | ||
115 | If THUNK returns nil, we display BUFFER starting at the top, and | |
116 | shrink the window to fit. If THUNK returns non-nil, we don't do those | |
117 | things. | |
118 | ||
d5b9d1d8 JB |
119 | When the user exits (with `electric-help-exit', or otherwise) the help |
120 | buffer's window disappears (i.e., we use `save-window-excursion') | |
9dd2b34e | 121 | BUFFER is put into `default-major-mode' (or `fundamental-mode') when we exit." |
a2535589 JA |
122 | (setq buffer (get-buffer-create (or buffer "*Help*"))) |
123 | (let ((one (one-window-p t)) | |
88c269cb | 124 | (config (current-window-configuration)) |
f98e758c | 125 | (bury nil) |
db30b383 | 126 | (electric-help-form-to-execute nil)) |
88c269cb | 127 | (unwind-protect |
128 | (save-excursion | |
129 | (if one (goto-char (window-start (selected-window)))) | |
130 | (let ((pop-up-windows t)) | |
131 | (pop-to-buffer buffer)) | |
132 | (save-excursion | |
133 | (set-buffer buffer) | |
f98e758c RS |
134 | (if (and minheight (< (window-height) minheight)) |
135 | (enlarge-window (- minheight (window-height)))) | |
88c269cb | 136 | (electric-help-mode) |
e024a2f4 | 137 | (setq buffer-read-only nil) |
db30b383 | 138 | (or noerase |
e024a2f4 | 139 | (erase-buffer))) |
88c269cb | 140 | (let ((standard-output buffer)) |
141 | (if (not (funcall thunk)) | |
142 | (progn | |
143 | (set-buffer buffer) | |
144 | (set-buffer-modified-p nil) | |
145 | (goto-char (point-min)) | |
146 | (if one (shrink-window-if-larger-than-buffer (selected-window)))))) | |
147 | (set-buffer buffer) | |
148 | (run-hooks 'electric-help-mode-hook) | |
e024a2f4 | 149 | (setq buffer-read-only t) |
88c269cb | 150 | (if (eq (car-safe (electric-help-command-loop)) |
151 | 'retain) | |
152 | (setq config (current-window-configuration)) | |
9201fa06 RS |
153 | (setq bury t)) |
154 | ;; Remove the hook. | |
155 | (if (memq 'electric-help-retain mouse-leave-buffer-hook) | |
156 | (remove-hook 'mouse-leave-buffer-hook 'electric-help-retain))) | |
88c269cb | 157 | (message "") |
158 | (set-buffer buffer) | |
159 | (setq buffer-read-only nil) | |
160 | (condition-case () | |
161 | (funcall (or default-major-mode 'fundamental-mode)) | |
162 | (error nil)) | |
163 | (set-window-configuration config) | |
164 | (if bury | |
165 | (progn | |
166 | ;;>> Perhaps this shouldn't be done. | |
167 | ;; so that when we say "Press space to bury" we mean it | |
168 | (replace-buffer-in-windows buffer) | |
169 | ;; must do this outside of save-window-excursion | |
f98e758c | 170 | (bury-buffer buffer))) |
db30b383 | 171 | (eval electric-help-form-to-execute)))) |
a2535589 JA |
172 | |
173 | (defun electric-help-command-loop () | |
174 | (catch 'exit | |
175 | (if (pos-visible-in-window-p (point-max)) | |
7bccdfbc | 176 | (progn (message "%s" (substitute-command-keys "<<< Press Space to bury the help buffer, Press \\[electric-help-retain] to retain it >>>")) |
70447f8c RS |
177 | (if (equal (setq unread-command-events (list (read-event))) |
178 | '(?\ )) | |
dbc4e1c1 | 179 | (progn (setq unread-command-events nil) |
a2535589 JA |
180 | (throw 'exit t))))) |
181 | (let (up down both neither | |
182 | (standard (and (eq (key-binding " ") | |
183 | 'scroll-up) | |
184 | (eq (key-binding "\^?") | |
185 | 'scroll-down) | |
a2535589 | 186 | (eq (key-binding "q") |
e27ef4db RS |
187 | 'electric-help-exit) |
188 | (eq (key-binding "r") | |
189 | 'electric-help-retain)))) | |
a2535589 JA |
190 | (Electric-command-loop |
191 | 'exit | |
192 | (function (lambda () | |
f98e758c RS |
193 | (sit-for 0) ;necessary if last command was end-of-buffer or |
194 | ;beginning-of-buffer - otherwise pos-visible-in-window-p | |
195 | ;will yield a wrong result. | |
a2535589 JA |
196 | (let ((min (pos-visible-in-window-p (point-min))) |
197 | (max (pos-visible-in-window-p (point-max)))) | |
f98e758c RS |
198 | (cond (isearch-mode 'noprompt) |
199 | ((and min max) | |
e27ef4db | 200 | (cond (standard "Press q to exit, r to retain ") |
a2535589 | 201 | (neither) |
e27ef4db | 202 | (t (setq neither (substitute-command-keys "Press \\[electric-help-exit] to exit, \\[electric-help-retain] to retain "))))) |
a2535589 | 203 | (min |
e27ef4db | 204 | (cond (standard "Press SPC to scroll, q to exit, r to retain ") |
a2535589 | 205 | (up) |
e27ef4db | 206 | (t (setq up (substitute-command-keys "Press \\[scroll-up] to scroll, \\[electric-help-exit] to exit, \\[electric-help-retain] to retain "))))) |
a2535589 | 207 | (max |
f98e758c | 208 | (cond (standard "Press DEL to scroll back, q to exit, r to retain ") |
a2535589 | 209 | (down) |
e27ef4db | 210 | (t (setq down (substitute-command-keys "Press \\[scroll-down] to scroll back, \\[electric-help-exit] to exit, \\[electric-help-retain] to retain "))))) |
a2535589 | 211 | (t |
f98e758c | 212 | (cond (standard "Press SPC to scroll, DEL to scroll back, q to exit, r to retain ") |
a2535589 | 213 | (both) |
e27ef4db | 214 | (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 "))))))))) |
a2535589 JA |
215 | t)))) |
216 | ||
217 | ||
218 | \f | |
219 | ;(defun electric-help-scroll-up (arg) | |
220 | ; ">>>Doc" | |
221 | ; (interactive "P") | |
222 | ; (if (and (null arg) (pos-visible-in-window-p (point-max))) | |
223 | ; (electric-help-exit) | |
224 | ; (scroll-up arg))) | |
225 | ||
226 | (defun electric-help-exit () | |
9201fa06 RS |
227 | "Exit `electric-help', restoring the previous window/buffer configuration. |
228 | \(The *Help* buffer will be buried.)" | |
a2535589 | 229 | (interactive) |
9201fa06 RS |
230 | ;; Make sure that we don't throw twice, even if two events cause |
231 | ;; calling this function: | |
232 | (if (memq 'electric-help-retain mouse-leave-buffer-hook) | |
233 | (progn | |
234 | (remove-hook 'mouse-leave-buffer-hook 'electric-help-retain) | |
235 | (throw 'exit t)))) | |
a2535589 JA |
236 | |
237 | (defun electric-help-retain () | |
d5b9d1d8 | 238 | "Exit `electric-help', retaining the current window/buffer configuration. |
a2535589 JA |
239 | \(The *Help* buffer will not be selected, but \\[switch-to-buffer-other-window] RET |
240 | will select it.)" | |
241 | (interactive) | |
f98e758c RS |
242 | ;; Make sure that we don't throw twice, even if two events cause |
243 | ;; calling this function: | |
2e8174d2 RS |
244 | (if (memq 'electric-help-retain mouse-leave-buffer-hook) |
245 | (progn | |
246 | (remove-hook 'mouse-leave-buffer-hook 'electric-help-retain) | |
247 | (throw 'exit '(retain))))) | |
a2535589 JA |
248 | |
249 | ||
a2535589 JA |
250 | (defun electric-help-undefined () |
251 | (interactive) | |
252 | (error "%s is undefined -- Press %s to exit" | |
253 | (mapconcat 'single-key-description (this-command-keys) " ") | |
f98e758c RS |
254 | (if (eq (key-binding "q") 'electric-help-exit) |
255 | "q" | |
a2535589 JA |
256 | (substitute-command-keys "\\[electric-help-exit]")))) |
257 | ||
258 | ||
259 | ;>>> this needs to be hairified (recursive help, anybody?) | |
260 | (defun electric-help-help () | |
261 | (interactive) | |
e27ef4db | 262 | (if (and (eq (key-binding "q") 'electric-help-exit) |
a2535589 | 263 | (eq (key-binding " ") 'scroll-up) |
e27ef4db RS |
264 | (eq (key-binding "\^?") 'scroll-down) |
265 | (eq (key-binding "r") 'electric-help-retain)) | |
266 | (message "SPC scrolls up, DEL scrolls down, q exits burying help buffer, r exits") | |
267 | (message "%s" (substitute-command-keys "\\[scroll-up] scrolls up, \\[scroll-down] scrolls down, \\[electric-help-exit] exits burying help buffer, \\[electric-help-retain] exits"))) | |
a2535589 JA |
268 | (sit-for 2)) |
269 | ||
270 | \f | |
9dd2b34e | 271 | ;;;###autoload |
1676b298 RS |
272 | (defun electric-helpify (fun &optional name) |
273 | (let ((name (or name "*Help*"))) | |
a2535589 JA |
274 | (if (save-window-excursion |
275 | ;; kludge-o-rama | |
276 | (let* ((p (symbol-function 'print-help-return-message)) | |
277 | (b (get-buffer name)) | |
278 | (m (buffer-modified-p b))) | |
279 | (and b (not (get-buffer-window b)) | |
280 | (setq b nil)) | |
281 | (unwind-protect | |
282 | (progn | |
283 | (message "%s..." (capitalize (symbol-name fun))) | |
284 | ;; with-output-to-temp-buffer marks the buffer as unmodified. | |
285 | ;; kludging excessively and relying on that as some sort | |
286 | ;; of indication leads to the following abomination... | |
287 | ;;>> This would be doable without such icky kludges if either | |
288 | ;;>> (a) there were a function to read the interactive | |
289 | ;;>> args for a command and return a list of those args. | |
290 | ;;>> (To which one would then just apply the command) | |
291 | ;;>> (The only problem with this is that interactive-p | |
292 | ;;>> would break, but that is such a misfeature in | |
293 | ;;>> any case that I don't care) | |
294 | ;;>> It is easy to do this for emacs-lisp functions; | |
295 | ;;>> the only problem is getting the interactive spec | |
296 | ;;>> for subrs | |
297 | ;;>> (b) there were a function which returned a | |
298 | ;;>> modification-tick for a buffer. One could tell | |
299 | ;;>> whether a buffer had changed by whether the | |
300 | ;;>> modification-tick were different. | |
301 | ;;>> (Presumably there would have to be a way to either | |
302 | ;;>> restore the tick to some previous value, or to | |
303 | ;;>> suspend updating of the tick in order to allow | |
304 | ;;>> things like momentary-string-display) | |
305 | (and b | |
306 | (save-excursion | |
307 | (set-buffer b) | |
308 | (set-buffer-modified-p t))) | |
309 | (fset 'print-help-return-message 'ignore) | |
310 | (call-interactively fun) | |
311 | (and (get-buffer name) | |
312 | (get-buffer-window (get-buffer name)) | |
313 | (or (not b) | |
314 | (not (eq b (get-buffer name))) | |
315 | (not (buffer-modified-p b))))) | |
316 | (fset 'print-help-return-message p) | |
317 | (and b (buffer-name b) | |
318 | (save-excursion | |
319 | (set-buffer b) | |
320 | (set-buffer-modified-p m)))))) | |
321 | (with-electric-help 'ignore name t)))) | |
322 | ||
323 | \f | |
f98e758c RS |
324 | |
325 | ;; This is to be bound to M-x in ehelp mode. Retains ehelp buffer and then | |
326 | ;; continues with execute-extended-command. | |
327 | (defun electric-help-execute-extended (prefixarg) | |
328 | (interactive "p") | |
db30b383 | 329 | (setq electric-help-form-to-execute '(execute-extended-command nil)) |
f98e758c RS |
330 | (electric-help-retain)) |
331 | ||
332 | ;; This is to be buond to C-x in ehelp mode. Retains ehelp buffer and then | |
333 | ;; continues with ctrl-x prefix. | |
334 | (defun electric-help-ctrl-x-prefix (prefixarg) | |
335 | (interactive "p") | |
db30b383 | 336 | (setq electric-help-form-to-execute '(progn (message nil) (setq unread-command-char ?\C-x))) |
f98e758c RS |
337 | (electric-help-retain)) |
338 | ||
339 | \f | |
a2535589 JA |
340 | (defun electric-describe-key () |
341 | (interactive) | |
342 | (electric-helpify 'describe-key)) | |
343 | ||
344 | (defun electric-describe-mode () | |
345 | (interactive) | |
346 | (electric-helpify 'describe-mode)) | |
347 | ||
348 | (defun electric-view-lossage () | |
349 | (interactive) | |
350 | (electric-helpify 'view-lossage)) | |
351 | ||
352 | ;(defun electric-help-for-help () | |
353 | ; "See help-for-help" | |
354 | ; (interactive) | |
355 | ; ) | |
356 | ||
357 | (defun electric-describe-function () | |
358 | (interactive) | |
359 | (electric-helpify 'describe-function)) | |
360 | ||
361 | (defun electric-describe-variable () | |
362 | (interactive) | |
363 | (electric-helpify 'describe-variable)) | |
364 | ||
365 | (defun electric-describe-bindings () | |
366 | (interactive) | |
367 | (electric-helpify 'describe-bindings)) | |
368 | ||
369 | (defun electric-describe-syntax () | |
370 | (interactive) | |
371 | (electric-helpify 'describe-syntax)) | |
372 | ||
373 | (defun electric-command-apropos () | |
374 | (interactive) | |
1676b298 | 375 | (electric-helpify 'command-apropos "*Apropos*")) |
a2535589 JA |
376 | |
377 | ;(define-key help-map "a" 'electric-command-apropos) | |
378 | ||
e27ef4db RS |
379 | (defun electric-apropos () |
380 | (interactive) | |
381 | (electric-helpify 'apropos)) | |
a2535589 | 382 | |
a2535589 JA |
383 | \f |
384 | ;;;; ehelp-map | |
385 | ||
386 | (defvar ehelp-map ()) | |
387 | (if ehelp-map | |
388 | nil | |
389 | (let ((map (copy-keymap help-map))) | |
f98e758c | 390 | (substitute-key-definition 'apropos 'electric-apropos map) |
e27ef4db | 391 | (substitute-key-definition 'command-apropos 'electric-command-apropos map) |
a2535589 JA |
392 | (substitute-key-definition 'describe-key 'electric-describe-key map) |
393 | (substitute-key-definition 'describe-mode 'electric-describe-mode map) | |
394 | (substitute-key-definition 'view-lossage 'electric-view-lossage map) | |
395 | (substitute-key-definition 'describe-function 'electric-describe-function map) | |
396 | (substitute-key-definition 'describe-variable 'electric-describe-variable map) | |
397 | (substitute-key-definition 'describe-bindings 'electric-describe-bindings map) | |
398 | (substitute-key-definition 'describe-syntax 'electric-describe-syntax map) | |
399 | ||
400 | (setq ehelp-map map) | |
401 | (fset 'ehelp-command map))) | |
402 | ||
49116ac0 JB |
403 | (provide 'ehelp) |
404 | ||
c0274f38 | 405 | ;;; ehelp.el ends here |