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1.1 root 1: ;; Copyright (C) 1986 Free Software Foundation, Inc.
2:
3: ;; This file is part of GNU Emacs.
4:
5: ;; GNU Emacs is free software; you can redistribute it and/or modify
6: ;; it under the terms of the GNU General Public License as published by
7: ;; the Free Software Foundation; either version 1, or (at your option)
8: ;; any later version.
9:
10: ;; GNU Emacs is distributed in the hope that it will be useful,
11: ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
12: ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13: ;; GNU General Public License for more details.
14:
15: ;; You should have received a copy of the GNU General Public License
16: ;; along with GNU Emacs; see the file COPYING. If not, write to
17: ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
18:
19: (require 'electric)
20: (provide 'ehelp)
21:
22: (defvar electric-help-map ()
23: "Keymap defining commands available whilst scrolling
24: through a buffer in electric-help-mode")
25:
26: (put 'electric-help-undefined 'suppress-keymap t)
27: (if electric-help-map
28: ()
29: (let ((map (make-keymap)))
30: (fillarray map 'electric-help-undefined)
31: (define-key map (char-to-string meta-prefix-char) (copy-keymap map))
32: (define-key map (char-to-string help-char) 'electric-help-help)
33: (define-key map "?" 'electric-help-help)
34: (define-key map " " 'scroll-up)
35: (define-key map "\^?" 'scroll-down)
36: (define-key map "." 'beginning-of-buffer)
37: (define-key map "<" 'beginning-of-buffer)
38: (define-key map ">" 'end-of-buffer)
39: ;(define-key map "\C-g" 'electric-help-exit)
40: (define-key map "q" 'electric-help-exit)
41: (define-key map "Q" 'electric-help-exit)
42: ;;a better key than this?
43: (define-key map "r" 'electric-help-retain)
44:
45: (setq electric-help-map map)))
46:
47: (defun electric-help-mode ()
48: "with-electric-help temporarily places its buffer in this mode
49: \(On exit from with-electric-help, the buffer is put in default-major-mode)"
50: (setq buffer-read-only t)
51: (setq mode-name "Help")
52: (setq major-mode 'help)
53: (setq mode-line-buffer-identification '(" Help: %b"))
54: (use-local-map electric-help-map)
55: ;; this is done below in with-electric-help
56: ;(run-hooks 'electric-help-mode-hook)
57: )
58:
59: (defun with-electric-help (thunk &optional buffer noerase)
60: "Arguments are THUNK &optional BUFFER NOERASE.
61: BUFFER defaults to \"*Help*\"
62: THUNK is a function of no arguments which is called to initialise
63: the contents of BUFFER. BUFFER will be erased before THUNK is called unless
64: NOERASE is non-nil. THUNK will be called with standard-output bound to
65: the buffer specified by BUFFER
66:
67: After THUNK has been called, this function \"electrically\" pops up a window
68: in which BUFFER is displayed and allows the user to scroll through that buffer
69: in electric-help-mode.
70: When the user exits (with electric-help-exit, or otherwise) the help
71: buffer's window disappears (ie we use save-window-excursion)
72: BUFFER is put into default-major-mode (or fundamental-mode) when we exit"
73: (setq buffer (get-buffer-create (or buffer "*Help*")))
74: (let ((one (one-window-p t))
75: (two nil))
76: (save-window-excursion
77: (save-excursion
78: (if one (goto-char (window-start (selected-window))))
79: (let ((pop-up-windows t))
80: (pop-to-buffer buffer))
81: (unwind-protect
82: (progn
83: (save-excursion
84: (set-buffer buffer)
85: (electric-help-mode)
86: (setq buffer-read-only nil)
87: (or noerase (erase-buffer)))
88: (let ((standard-output buffer))
89: (if (funcall thunk)
90: ()
91: (set-buffer buffer)
92: (set-buffer-modified-p nil)
93: (goto-char (point-min))
94: (if one (shrink-window-if-larger-than-buffer (selected-window)))))
95: (set-buffer buffer)
96: (run-hooks 'electric-help-mode-hook)
97: (setq two (electric-help-command-loop))
98: (cond ((eq (car-safe two) 'retain)
99: (setq two (vector (window-height (selected-window))
100: (window-start (selected-window))
101: (window-hscroll (selected-window))
102: (point))))
103: (t (setq two nil))))
104:
105: (message "")
106: (set-buffer buffer)
107: (setq buffer-read-only nil)
108: (condition-case ()
109: (funcall (or default-major-mode 'fundamental-mode))
110: (error nil)))))
111: (if two
112: (let ((pop-up-windows t)
113: tem)
114: (pop-to-buffer buffer)
115: (setq tem (- (window-height (selected-window)) (elt two 0)))
116: (if (> tem 0) (shrink-window tem))
117: (set-window-start (selected-window) (elt two 1) t)
118: (set-window-hscroll (selected-window) (elt two 2))
119: (goto-char (elt two 3)))
120: ;;>> Perhaps this shouldn't be done.
121: ;; so that when we say "Press space to bury" we mean it
122: (replace-buffer-in-windows buffer)
123: ;; must do this outside of save-window-excursion
124: (bury-buffer buffer))))
125:
126: (defun electric-help-command-loop ()
127: (catch 'exit
128: (if (pos-visible-in-window-p (point-max))
129: (progn (message "<<< Press Space to bury the help buffer >>>")
130: (if (= (setq unread-command-char (read-char)) ?\ )
131: (progn (setq unread-command-char -1)
132: (throw 'exit t)))))
133: (let (up down both neither
134: (standard (and (eq (key-binding " ")
135: 'scroll-up)
136: (eq (key-binding "\^?")
137: 'scroll-down)
138: (eq (key-binding "Q")
139: 'electric-help-exit)
140: (eq (key-binding "q")
141: 'electric-help-exit))))
142: (Electric-command-loop
143: 'exit
144: (function (lambda ()
145: (let ((min (pos-visible-in-window-p (point-min)))
146: (max (pos-visible-in-window-p (point-max))))
147: (cond ((and min max)
148: (cond (standard "Press Q to exit ")
149: (neither)
150: (t (setq neither (substitute-command-keys "Press \\[scroll-up] to exit ")))))
151: (min
152: (cond (standard "Press SPC to scroll, Q to exit ")
153: (up)
154: (t (setq up (substitute-command-keys "Press \\[scroll-up] to scroll; \\[electric-help-exit] to exit ")))))
155: (max
156: (cond (standard "Press DEL to scroll back, Q to exit ")
157: (down)
158: (t (setq down (substitute-command-keys "Press \\[scroll-down] to scroll back, \\[scroll-up] to exit ")))))
159: (t
160: (cond (standard "Press SPC to scroll, DEL to scroll back, Q to exit ")
161: (both)
162: (t (setq both (substitute-command-keys "Press \\[scroll-up] to scroll, \\[scroll-down] to scroll back, \\[electric-help-exit] to exit ")))))))))
163: t))))
164:
165:
166:
167: ;(defun electric-help-scroll-up (arg)
168: ; ">>>Doc"
169: ; (interactive "P")
170: ; (if (and (null arg) (pos-visible-in-window-p (point-max)))
171: ; (electric-help-exit)
172: ; (scroll-up arg)))
173:
174: (defun electric-help-exit ()
175: ">>>Doc"
176: (interactive)
177: (throw 'exit t))
178:
179: (defun electric-help-retain ()
180: "Exit electric-help, retaining the current window/buffer conifiguration.
181: \(The *Help* buffer will not be selected, but \\[switch-to-buffer-other-window] RET
182: will select it.)"
183: (interactive)
184: (throw 'exit '(retain)))
185:
186:
187: ;(defun electric-help-undefined ()
188: ; (interactive)
189: ; (let* ((keys (this-command-keys))
190: ; (n (length keys)))
191: ; (if (or (= n 1)
192: ; (and (= n 2)
193: ; meta-flag
194: ; (eq (aref keys 0) meta-prefix-char)))
195: ; (setq unread-command-char last-input-char
196: ; current-prefix-arg prefix-arg)
197: ; ;;>>> I don't care.
198: ; ;;>>> The emacs command-loop is too much pure pain to
199: ; ;;>>> duplicate
200: ; ))
201: ; (throw 'exit t))
202:
203: (defun electric-help-undefined ()
204: (interactive)
205: (error "%s is undefined -- Press %s to exit"
206: (mapconcat 'single-key-description (this-command-keys) " ")
207: (if (eq (key-binding "Q") 'electric-help-exit)
208: "Q"
209: (substitute-command-keys "\\[electric-help-exit]"))))
210:
211:
212: ;>>> this needs to be hairified (recursive help, anybody?)
213: (defun electric-help-help ()
214: (interactive)
215: (if (and (eq (key-binding "Q") 'electric-help-exit)
216: (eq (key-binding " ") 'scroll-up)
217: (eq (key-binding "\^?") 'scroll-down))
218: (message "SPC scrolls forward, DEL scrolls back, Q exits and burys help buffer")
219: ;; to give something for user to look at while slow substitute-cmd-keys
220: ;; grinds away
221: (message "Help...")
222: (message "%s" (substitute-command-keys "\\[scroll-up] scrolls forward, \\[scroll-down] scrolls back, \\[electric-help-exit] exits.")))
223: (sit-for 2))
224:
225:
226: (defun electric-helpify (fun)
227: (let ((name "*Help*"))
228: (if (save-window-excursion
229: ;; kludge-o-rama
230: (let* ((p (symbol-function 'print-help-return-message))
231: (b (get-buffer name))
232: (m (buffer-modified-p b)))
233: (and b (not (get-buffer-window b))
234: (setq b nil))
235: (unwind-protect
236: (progn
237: (message "%s..." (capitalize (symbol-name fun)))
238: ;; with-output-to-temp-buffer marks the buffer as unmodified.
239: ;; kludging excessively and relying on that as some sort
240: ;; of indication leads to the following abomination...
241: ;;>> This would be doable without such icky kludges if either
242: ;;>> (a) there were a function to read the interactive
243: ;;>> args for a command and return a list of those args.
244: ;;>> (To which one would then just apply the command)
245: ;;>> (The only problem with this is that interactive-p
246: ;;>> would break, but that is such a misfeature in
247: ;;>> any case that I don't care)
248: ;;>> It is easy to do this for emacs-lisp functions;
249: ;;>> the only problem is getting the interactive spec
250: ;;>> for subrs
251: ;;>> (b) there were a function which returned a
252: ;;>> modification-tick for a buffer. One could tell
253: ;;>> whether a buffer had changed by whether the
254: ;;>> modification-tick were different.
255: ;;>> (Presumably there would have to be a way to either
256: ;;>> restore the tick to some previous value, or to
257: ;;>> suspend updating of the tick in order to allow
258: ;;>> things like momentary-string-display)
259: (and b
260: (save-excursion
261: (set-buffer b)
262: (set-buffer-modified-p t)))
263: (fset 'print-help-return-message 'ignore)
264: (call-interactively fun)
265: (and (get-buffer name)
266: (get-buffer-window (get-buffer name))
267: (or (not b)
268: (not (eq b (get-buffer name)))
269: (not (buffer-modified-p b)))))
270: (fset 'print-help-return-message p)
271: (and b (buffer-name b)
272: (save-excursion
273: (set-buffer b)
274: (set-buffer-modified-p m))))))
275: (with-electric-help 'ignore name t))))
276:
277:
278: (defun electric-describe-key ()
279: (interactive)
280: (electric-helpify 'describe-key))
281:
282: (defun electric-describe-mode ()
283: (interactive)
284: (electric-helpify 'describe-mode))
285:
286: (defun electric-view-lossage ()
287: (interactive)
288: (electric-helpify 'view-lossage))
289:
290: ;(defun electric-help-for-help ()
291: ; "See help-for-help"
292: ; (interactive)
293: ; )
294:
295: (defun electric-describe-function ()
296: (interactive)
297: (electric-helpify 'describe-function))
298:
299: (defun electric-describe-variable ()
300: (interactive)
301: (electric-helpify 'describe-variable))
302:
303: (defun electric-describe-bindings ()
304: (interactive)
305: (electric-helpify 'describe-bindings))
306:
307: (defun electric-describe-syntax ()
308: (interactive)
309: (electric-helpify 'describe-syntax))
310:
311: (defun electric-command-apropos ()
312: (interactive)
313: (electric-helpify 'command-apropos))
314:
315: ;(define-key help-map "a" 'electric-command-apropos)
316:
317:
318:
319:
320: ;;;; ehelp-map
321:
322: (defvar ehelp-map ())
323: (if ehelp-map
324: nil
325: (let ((map (copy-keymap help-map)))
326: (substitute-key-definition 'describe-key 'electric-describe-key map)
327: (substitute-key-definition 'describe-mode 'electric-describe-mode map)
328: (substitute-key-definition 'view-lossage 'electric-view-lossage map)
329: (substitute-key-definition 'describe-function 'electric-describe-function map)
330: (substitute-key-definition 'describe-variable 'electric-describe-variable map)
331: (substitute-key-definition 'describe-bindings 'electric-describe-bindings map)
332: (substitute-key-definition 'describe-syntax 'electric-describe-syntax map)
333:
334: (setq ehelp-map map)
335: (fset 'ehelp-command map)))
336:
337: ;; Do (define-key global-map "\C-h" 'ehelp-command) if you want to win
338:
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