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1 | ;;; help-mode.el --- `help-mode' used by *Help* buffers |
2 | ||
0d30b337 | 3 | ;; Copyright (C) 1985, 1986, 1993, 1994, 1998, 1999, 2000, 2001, 2002, |
d7a0267c | 4 | ;; 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc. |
f4ed5b19 MB |
5 | |
6 | ;; Maintainer: FSF | |
7 | ;; Keywords: help, internal | |
8 | ||
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 | |
13 | ;; the Free Software Foundation; either version 2, or (at your option) | |
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 | |
22 | ;; along with GNU Emacs; see the file COPYING. If not, write to the | |
086add15 LK |
23 | ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
24 | ;; Boston, MA 02110-1301, USA. | |
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25 | |
26 | ;;; Commentary: | |
27 | ||
28 | ;; Defines `help-mode', which is the mode used by *Help* buffers, and | |
29 | ;; associated support machinery, such as adding hyperlinks, etc., | |
30 | ||
31 | ;;; Code: | |
32 | ||
33 | (require 'button) | |
410e58b5 | 34 | (require 'view) |
f4ed5b19 MB |
35 | |
36 | (defvar help-mode-map (make-sparse-keymap) | |
37 | "Keymap for help mode.") | |
38 | ||
39 | (set-keymap-parent help-mode-map button-buffer-map) | |
40 | ||
89f5b33f | 41 | (define-key help-mode-map [mouse-2] 'help-follow-mouse) |
f4ed5b19 | 42 | (define-key help-mode-map "\C-c\C-b" 'help-go-back) |
95f731db | 43 | (define-key help-mode-map "\C-c\C-f" 'help-go-forward) |
8a31f813 | 44 | (define-key help-mode-map "\C-c\C-c" 'help-follow-symbol) |
f4ed5b19 MB |
45 | ;; Documentation only, since we use minor-mode-overriding-map-alist. |
46 | (define-key help-mode-map "\r" 'help-follow) | |
47 | ||
48 | (defvar help-xref-stack nil | |
49 | "A stack of ways by which to return to help buffers after following xrefs. | |
50 | Used by `help-follow' and `help-xref-go-back'. | |
89f5b33f SM |
51 | An element looks like (POSITION FUNCTION ARGS...). |
52 | To use the element, do (apply FUNCTION ARGS) then goto the point.") | |
f4ed5b19 | 53 | (put 'help-xref-stack 'permanent-local t) |
89f5b33f | 54 | (make-variable-buffer-local 'help-xref-stack) |
f4ed5b19 | 55 | |
95f731db NR |
56 | (defvar help-xref-forward-stack nil |
57 | "The stack of used to navigate help forwards after using the back button. | |
58 | Used by `help-follow' and `help-xref-go-forward'. | |
59 | An element looks like (POSITION FUNCTION ARGS...). | |
60 | To use the element, do (apply FUNCTION ARGS) then goto the point.") | |
61 | (put 'help-xref-forward-stack 'permanent-local t) | |
62 | (make-variable-buffer-local 'help-xref-forward-stack) | |
63 | ||
f4ed5b19 MB |
64 | (defvar help-xref-stack-item nil |
65 | "An item for `help-follow' in this buffer to push onto `help-xref-stack'. | |
66 | The format is (FUNCTION ARGS...).") | |
67 | (put 'help-xref-stack-item 'permanent-local t) | |
89f5b33f | 68 | (make-variable-buffer-local 'help-xref-stack-item) |
f4ed5b19 | 69 | |
95f731db NR |
70 | (defvar help-xref-stack-forward-item nil |
71 | "An item for `help-go-back' to push onto `help-xref-forward-stack'. | |
72 | The format is (FUNCTION ARGS...).") | |
73 | (put 'help-xref-stack-forward-item 'permanent-local t) | |
74 | (make-variable-buffer-local 'help-xref-stack-forward-item) | |
75 | ||
f4ed5b19 | 76 | (setq-default help-xref-stack nil help-xref-stack-item nil) |
95f731db | 77 | (setq-default help-xref-forward-stack nil help-xref-forward-stack-item nil) |
f4ed5b19 | 78 | |
1700f41d RS |
79 | (defcustom help-mode-hook nil |
80 | "Hook run by `help-mode'." | |
81 | :type 'hook | |
82 | :group 'help) | |
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83 | \f |
84 | ;; Button types used by help | |
85 | ||
6e881567 | 86 | (define-button-type 'help-xref |
54d761b3 | 87 | 'follow-link t |
6e881567 MB |
88 | 'action #'help-button-action) |
89 | ||
90 | (defun help-button-action (button) | |
91 | "Call BUTTON's help function." | |
92 | (help-do-xref (button-start button) | |
93 | (button-get button 'help-function) | |
94 | (button-get button 'help-args))) | |
95 | ||
7e2a83df RS |
96 | ;; These 6 calls to define-button-type were generated in a dolist |
97 | ;; loop, but that is bad because it means these button types don't | |
98 | ;; have an easily found definition. | |
99 | ||
100 | (define-button-type 'help-function | |
101 | :supertype 'help-xref | |
102 | 'help-function 'describe-function | |
103 | 'help-echo (purecopy "mouse-2, RET: describe this function")) | |
104 | ||
105 | (define-button-type 'help-variable | |
106 | :supertype 'help-xref | |
107 | 'help-function 'describe-variable | |
108 | 'help-echo (purecopy "mouse-2, RET: describe this variable")) | |
109 | ||
110 | (define-button-type 'help-face | |
111 | :supertype 'help-xref | |
112 | 'help-function 'describe-face | |
113 | 'help-echo (purecopy "mouse-2, RET: describe this face")) | |
114 | ||
115 | (define-button-type 'help-coding-system | |
116 | :supertype 'help-xref | |
117 | 'help-function 'describe-coding-system | |
118 | 'help-echo (purecopy "mouse-2, RET: describe this coding system")) | |
119 | ||
120 | (define-button-type 'help-input-method | |
121 | :supertype 'help-xref | |
122 | 'help-function 'describe-input-method | |
123 | 'help-echo (purecopy "mouse-2, RET: describe this input method")) | |
124 | ||
125 | (define-button-type 'help-character-set | |
126 | :supertype 'help-xref | |
127 | 'help-function 'describe-character-set | |
128 | 'help-echo (purecopy "mouse-2, RET: describe this character set")) | |
f4ed5b19 MB |
129 | |
130 | ;; make some more ideosyncratic button types | |
131 | ||
132 | (define-button-type 'help-symbol | |
6e881567 | 133 | :supertype 'help-xref |
f4ed5b19 | 134 | 'help-function #'help-xref-interned |
6e881567 | 135 | 'help-echo (purecopy "mouse-2, RET: describe this symbol")) |
f4ed5b19 MB |
136 | |
137 | (define-button-type 'help-back | |
6e881567 | 138 | :supertype 'help-xref |
f4ed5b19 | 139 | 'help-function #'help-xref-go-back |
6e881567 | 140 | 'help-echo (purecopy "mouse-2, RET: go back to previous help buffer")) |
f4ed5b19 | 141 | |
95f731db NR |
142 | (define-button-type 'help-forward |
143 | :supertype 'help-xref | |
144 | 'help-function #'help-xref-go-forward | |
145 | 'help-echo (purecopy "mouse-2, RET: move forward to next help buffer")) | |
146 | ||
f4ed5b19 | 147 | (define-button-type 'help-info |
6e881567 | 148 | :supertype 'help-xref |
f4ed5b19 | 149 | 'help-function #'info |
5c825567 BW |
150 | 'help-echo (purecopy "mouse-2, RET: read this Info node")) |
151 | ||
152 | (define-button-type 'help-url | |
153 | :supertype 'help-xref | |
154 | 'help-function #'browse-url | |
155 | 'help-echo (purecopy "mouse-2, RET: view this URL in a browser")) | |
f4ed5b19 MB |
156 | |
157 | (define-button-type 'help-customize-variable | |
6e881567 | 158 | :supertype 'help-xref |
f4ed5b19 | 159 | 'help-function (lambda (v) |
f4ed5b19 | 160 | (customize-variable v)) |
6e881567 | 161 | 'help-echo (purecopy "mouse-2, RET: customize variable")) |
f4ed5b19 | 162 | |
07f904a3 | 163 | (define-button-type 'help-customize-face |
6e881567 | 164 | :supertype 'help-xref |
07f904a3 | 165 | 'help-function (lambda (v) |
07f904a3 | 166 | (customize-face v)) |
6e881567 | 167 | 'help-echo (purecopy "mouse-2, RET: customize face")) |
07f904a3 | 168 | |
f4ed5b19 | 169 | (define-button-type 'help-function-def |
6e881567 | 170 | :supertype 'help-xref |
f4ed5b19 MB |
171 | 'help-function (lambda (fun file) |
172 | (require 'find-func) | |
2ea0f8fd SM |
173 | (when (eq file 'C-source) |
174 | (setq file | |
175 | (help-C-file-name (indirect-function fun) 'fun))) | |
410e58b5 | 176 | ;; Don't use find-function-noselect because it follows |
f4ed5b19 | 177 | ;; aliases (which fails for built-in functions). |
410e58b5 | 178 | (let ((location |
2ea0f8fd | 179 | (find-function-search-for-symbol fun nil file))) |
f4ed5b19 | 180 | (pop-to-buffer (car location)) |
46ab7691 NR |
181 | (if (cdr location) |
182 | (goto-char (cdr location)) | |
183 | (message "Unable to find location in file")))) | |
6e881567 | 184 | 'help-echo (purecopy "mouse-2, RET: find function's definition")) |
f4ed5b19 MB |
185 | |
186 | (define-button-type 'help-variable-def | |
6e881567 | 187 | :supertype 'help-xref |
f4ed5b19 | 188 | 'help-function (lambda (var &optional file) |
2ea0f8fd SM |
189 | (when (eq file 'C-source) |
190 | (setq file (help-C-file-name var 'var))) | |
191 | (let ((location (find-variable-noselect var file))) | |
f4ed5b19 | 192 | (pop-to-buffer (car location)) |
46ab7691 NR |
193 | (if (cdr location) |
194 | (goto-char (cdr location)) | |
195 | (message "Unable to find location in file")))) | |
27313250 | 196 | 'help-echo (purecopy "mouse-2, RET: find variable's definition")) |
f4ed5b19 | 197 | |
12b42b71 RS |
198 | (define-button-type 'help-face-def |
199 | :supertype 'help-xref | |
200 | 'help-function (lambda (fun file) | |
201 | (require 'find-func) | |
202 | ;; Don't use find-function-noselect because it follows | |
203 | ;; aliases (which fails for built-in functions). | |
204 | (let ((location | |
205 | (find-function-search-for-symbol fun 'defface file))) | |
206 | (pop-to-buffer (car location)) | |
46ab7691 NR |
207 | (if (cdr location) |
208 | (goto-char (cdr location)) | |
209 | (message "Unable to find location in file")))) | |
12b42b71 RS |
210 | 'help-echo (purecopy "mouse-2, RET: find face's definition")) |
211 | ||
f4ed5b19 MB |
212 | \f |
213 | ;;;###autoload | |
1700f41d | 214 | (defun help-mode () |
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215 | "Major mode for viewing help text and navigating references in it. |
216 | Entry to this mode runs the normal hook `help-mode-hook'. | |
217 | Commands: | |
218 | \\{help-mode-map}" | |
1700f41d RS |
219 | (interactive) |
220 | (kill-all-local-variables) | |
221 | (use-local-map help-mode-map) | |
222 | (setq mode-name "Help") | |
223 | (setq major-mode 'help-mode) | |
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224 | (view-mode) |
225 | (make-local-variable 'view-no-disable-on-exit) | |
1700f41d | 226 | (setq view-no-disable-on-exit t) |
4bc1b836 RS |
227 | (setq view-exit-action (lambda (buffer) |
228 | (or (window-minibuffer-p (selected-window)) | |
229 | (one-window-p t) | |
230 | (delete-window)))) | |
40bd2cfb | 231 | (run-mode-hooks 'help-mode-hook)) |
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232 | |
233 | ;;;###autoload | |
234 | (defun help-mode-setup () | |
235 | (help-mode) | |
236 | (setq buffer-read-only nil)) | |
237 | ||
238 | ;;;###autoload | |
239 | (defun help-mode-finish () | |
69e73dd3 | 240 | (let ((entry (assq (selected-window) view-return-to-alist))) |
eac88b3b RS |
241 | (if entry |
242 | ;; When entering Help mode from the Help window, | |
243 | ;; such as by following a link, preserve the same | |
244 | ;; meaning for the q command. | |
245 | ;; (setcdr entry (cons (selected-window) help-return-method)) | |
246 | nil | |
69e73dd3 RS |
247 | (setq view-return-to-alist |
248 | (cons (cons (selected-window) help-return-method) | |
249 | view-return-to-alist)))) | |
f4ed5b19 MB |
250 | (when (eq major-mode 'help-mode) |
251 | ;; View mode's read-only status of existing *Help* buffer is lost | |
252 | ;; by with-output-to-temp-buffer. | |
253 | (toggle-read-only 1) | |
69e73dd3 | 254 | (help-make-xrefs (current-buffer)))) |
f4ed5b19 | 255 | \f |
410e58b5 SM |
256 | ;; Grokking cross-reference information in doc strings and |
257 | ;; hyperlinking it. | |
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258 | |
259 | ;; This may have some scope for extension and the same or something | |
260 | ;; similar should be done for widget doc strings, which currently use | |
261 | ;; another mechanism. | |
262 | ||
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263 | (defvar help-back-label (purecopy "[back]") |
264 | "Label to use by `help-make-xrefs' for the go-back reference.") | |
265 | ||
95f731db NR |
266 | (defvar help-forward-label (purecopy "[forward]") |
267 | "Label to use by `help-make-xrefs' for the go-forward reference.") | |
268 | ||
f4ed5b19 | 269 | (defconst help-xref-symbol-regexp |
8a31f813 | 270 | (purecopy (concat "\\(\\<\\(\\(variable\\|option\\)\\|" ; Link to var |
a79d3474 NR |
271 | "\\(function\\|command\\)\\|" ; Link to function |
272 | "\\(face\\)\\|" ; Link to face | |
273 | "\\(symbol\\|program\\|property\\)\\|" ; Don't link | |
040b2fa3 LT |
274 | "\\(source \\(?:code \\)?\\(?:of\\|for\\)\\)\\)" |
275 | "[ \t\n]+\\)?" | |
f4ed5b19 MB |
276 | ;; Note starting with word-syntax character: |
277 | "`\\(\\sw\\(\\sw\\|\\s_\\)+\\)'")) | |
278 | "Regexp matching doc string references to symbols. | |
279 | ||
280 | The words preceding the quoted symbol can be used in doc strings to | |
281 | distinguish references to variables, functions and symbols.") | |
282 | ||
410e58b5 | 283 | (defvar help-xref-mule-regexp nil |
f4ed5b19 MB |
284 | "Regexp matching doc string references to MULE-related keywords. |
285 | ||
286 | It is usually nil, and is temporarily bound to an appropriate regexp | |
287 | when help commands related to multilingual environment (e.g., | |
288 | `describe-coding-system') are invoked.") | |
289 | ||
290 | ||
291 | (defconst help-xref-info-regexp | |
2e10efeb | 292 | (purecopy "\\<[Ii]nfo[ \t\n]+\\(node\\|anchor\\)[ \t\n]+`\\([^']+\\)'") |
f4ed5b19 MB |
293 | "Regexp matching doc string references to an Info node.") |
294 | ||
5c825567 BW |
295 | (defconst help-xref-url-regexp |
296 | (purecopy "\\<[Uu][Rr][Ll][ \t\n]+`\\([^']+\\)'") | |
297 | "Regexp matching doc string references to a URL.") | |
298 | ||
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299 | ;;;###autoload |
300 | (defun help-setup-xref (item interactive-p) | |
301 | "Invoked from commands using the \"*Help*\" buffer to install some xref info. | |
302 | ||
303 | ITEM is a (FUNCTION . ARGS) pair appropriate for recreating the help | |
304 | buffer after following a reference. INTERACTIVE-P is non-nil if the | |
305 | calling command was invoked interactively. In this case the stack of | |
89f5b33f SM |
306 | items for help buffer \"back\" buttons is cleared. |
307 | ||
308 | This should be called very early, before the output buffer is cleared, | |
309 | because we want to record the \"previous\" position of point so we can | |
310 | restore it properly when going back." | |
311 | (with-current-buffer (help-buffer) | |
410e58b5 | 312 | (when help-xref-stack-item |
95f731db NR |
313 | (push (cons (point) help-xref-stack-item) help-xref-stack) |
314 | (setq help-xref-forward-stack nil)) | |
410e58b5 SM |
315 | (when interactive-p |
316 | (let ((tail (nthcdr 10 help-xref-stack))) | |
317 | ;; Truncate the stack. | |
318 | (if tail (setcdr tail nil)))) | |
89f5b33f | 319 | (setq help-xref-stack-item item))) |
f4ed5b19 MB |
320 | |
321 | (defvar help-xref-following nil | |
322 | "Non-nil when following a help cross-reference.") | |
323 | ||
89f5b33f | 324 | (defun help-buffer () |
89f5b33f SM |
325 | (buffer-name ;for with-output-to-temp-buffer |
326 | (if help-xref-following | |
327 | (current-buffer) | |
328 | (get-buffer-create "*Help*")))) | |
329 | ||
410e58b5 SM |
330 | (defvar help-xref-override-view-map |
331 | (let ((map (make-sparse-keymap))) | |
332 | (set-keymap-parent map view-mode-map) | |
333 | (define-key map "\r" nil) | |
334 | map) | |
335 | "Replacement keymap for `view-mode' in help buffers.") | |
336 | ||
f4ed5b19 MB |
337 | ;;;###autoload |
338 | (defun help-make-xrefs (&optional buffer) | |
339 | "Parse and hyperlink documentation cross-references in the given BUFFER. | |
340 | ||
d1282401 CW |
341 | Find cross-reference information in a buffer and activate such cross |
342 | references for selection with `help-follow'. Cross-references have | |
343 | the canonical form `...' and the type of reference may be | |
344 | disambiguated by the preceding word(s) used in | |
040b2fa3 LT |
345 | `help-xref-symbol-regexp'. Faces only get cross-referenced if |
346 | preceded or followed by the word `face'. Variables without | |
347 | variable documentation do not get cross-referenced, unless | |
9315fc34 | 348 | preceded by the word `variable' or `option'. |
f4ed5b19 MB |
349 | |
350 | If the variable `help-xref-mule-regexp' is non-nil, find also | |
351 | cross-reference information related to multilingual environment | |
352 | \(e.g., coding-systems). This variable is also used to disambiguate | |
353 | the type of reference as the same way as `help-xref-symbol-regexp'. | |
354 | ||
355 | A special reference `back' is made to return back through a stack of | |
356 | help buffers. Variable `help-back-label' specifies the text for | |
357 | that." | |
358 | (interactive "b") | |
359 | (save-excursion | |
360 | (set-buffer (or buffer (current-buffer))) | |
361 | (goto-char (point-min)) | |
362 | ;; Skip the header-type info, though it might be useful to parse | |
363 | ;; it at some stage (e.g. "function in `library'"). | |
364 | (forward-paragraph) | |
365 | (let ((old-modified (buffer-modified-p))) | |
366 | (let ((stab (syntax-table)) | |
367 | (case-fold-search t) | |
368 | (inhibit-read-only t)) | |
369 | (set-syntax-table emacs-lisp-mode-syntax-table) | |
370 | ;; The following should probably be abstracted out. | |
371 | (unwind-protect | |
372 | (progn | |
373 | ;; Info references | |
374 | (save-excursion | |
375 | (while (re-search-forward help-xref-info-regexp nil t) | |
2e10efeb | 376 | (let ((data (match-string 2))) |
f4ed5b19 MB |
377 | (save-match-data |
378 | (unless (string-match "^([^)]+)" data) | |
379 | (setq data (concat "(emacs)" data)))) | |
2e10efeb | 380 | (help-xref-button 2 'help-info data)))) |
5c825567 BW |
381 | ;; URLs |
382 | (save-excursion | |
383 | (while (re-search-forward help-xref-url-regexp nil t) | |
384 | (let ((data (match-string 1))) | |
385 | (help-xref-button 1 'help-url data)))) | |
f4ed5b19 MB |
386 | ;; Mule related keywords. Do this before trying |
387 | ;; `help-xref-symbol-regexp' because some of Mule | |
388 | ;; keywords have variable or function definitions. | |
389 | (if help-xref-mule-regexp | |
390 | (save-excursion | |
391 | (while (re-search-forward help-xref-mule-regexp nil t) | |
392 | (let* ((data (match-string 7)) | |
393 | (sym (intern-soft data))) | |
394 | (cond | |
395 | ((match-string 3) ; coding system | |
396 | (and sym (coding-system-p sym) | |
397 | (help-xref-button 6 'help-coding-system sym))) | |
398 | ((match-string 4) ; input method | |
399 | (and (assoc data input-method-alist) | |
400 | (help-xref-button 7 'help-input-method data))) | |
401 | ((or (match-string 5) (match-string 6)) ; charset | |
402 | (and sym (charsetp sym) | |
403 | (help-xref-button 7 'help-character-set sym))) | |
404 | ((assoc data input-method-alist) | |
405 | (help-xref-button 7 'help-character-set data)) | |
406 | ((and sym (coding-system-p sym)) | |
407 | (help-xref-button 7 'help-coding-system sym)) | |
408 | ((and sym (charsetp sym)) | |
409 | (help-xref-button 7 'help-character-set sym))))))) | |
410 | ;; Quoted symbols | |
411 | (save-excursion | |
412 | (while (re-search-forward help-xref-symbol-regexp nil t) | |
413 | (let* ((data (match-string 8)) | |
414 | (sym (intern-soft data))) | |
415 | (if sym | |
416 | (cond | |
040b2fa3 | 417 | ((match-string 3) ; `variable' &c |
e715d9b4 | 418 | (and (or (boundp sym) ; `variable' doesn't ensure |
f4ed5b19 | 419 | ; it's actually bound |
e715d9b4 | 420 | (get sym 'variable-documentation)) |
f4ed5b19 | 421 | (help-xref-button 8 'help-variable sym))) |
040b2fa3 | 422 | ((match-string 4) ; `function' &c |
f4ed5b19 MB |
423 | (and (fboundp sym) ; similarly |
424 | (help-xref-button 8 'help-function sym))) | |
425 | ((match-string 5) ; `face' | |
426 | (and (facep sym) | |
427 | (help-xref-button 8 'help-face sym))) | |
428 | ((match-string 6)) ; nothing for `symbol' | |
429 | ((match-string 7) | |
040b2fa3 LT |
430 | ;;; this used: |
431 | ;;; #'(lambda (arg) | |
432 | ;;; (let ((location | |
433 | ;;; (find-function-noselect arg))) | |
434 | ;;; (pop-to-buffer (car location)) | |
435 | ;;; (goto-char (cdr location)))) | |
f4ed5b19 | 436 | (help-xref-button 8 'help-function-def sym)) |
a1ef2eab JB |
437 | ((and |
438 | (facep sym) | |
439 | (save-match-data (looking-at "[ \t\n]+face\\W"))) | |
440 | (help-xref-button 8 'help-face sym)) | |
e715d9b4 LT |
441 | ((and (or (boundp sym) |
442 | (get sym 'variable-documentation)) | |
443 | (fboundp sym)) | |
f4ed5b19 MB |
444 | ;; We can't intuit whether to use the |
445 | ;; variable or function doc -- supply both. | |
446 | (help-xref-button 8 'help-symbol sym)) | |
040b2fa3 | 447 | ((and |
e715d9b4 LT |
448 | (or (boundp sym) |
449 | (get sym 'variable-documentation)) | |
1d0a6ebb JH |
450 | (or |
451 | (documentation-property | |
452 | sym 'variable-documentation) | |
453 | (condition-case nil | |
454 | (documentation-property | |
455 | (indirect-variable sym) | |
456 | 'variable-documentation) | |
457 | (cyclic-variable-indirection nil)))) | |
f4ed5b19 MB |
458 | (help-xref-button 8 'help-variable sym)) |
459 | ((fboundp sym) | |
b1664339 | 460 | (help-xref-button 8 'help-function sym))))))) |
f4ed5b19 MB |
461 | ;; An obvious case of a key substitution: |
462 | (save-excursion | |
463 | (while (re-search-forward | |
464 | ;; Assume command name is only word characters | |
465 | ;; and dashes to get things like `use M-x foo.'. | |
466 | "\\<M-x\\s-+\\(\\sw\\(\\sw\\|-\\)+\\)" nil t) | |
467 | (let ((sym (intern-soft (match-string 1)))) | |
468 | (if (fboundp sym) | |
469 | (help-xref-button 1 'help-function sym))))) | |
470 | ;; Look for commands in whole keymap substitutions: | |
471 | (save-excursion | |
472 | ;; Make sure to find the first keymap. | |
473 | (goto-char (point-min)) | |
474 | ;; Find a header and the column at which the command | |
475 | ;; name will be found. | |
ad4888e4 RS |
476 | |
477 | ;; If the keymap substitution isn't the last thing in | |
478 | ;; the doc string, and if there is anything on the | |
479 | ;; same line after it, this code won't recognize the end of it. | |
f4ed5b19 MB |
480 | (while (re-search-forward "^key +binding\n\\(-+ +\\)-+\n\n" |
481 | nil t) | |
482 | (let ((col (- (match-end 1) (match-beginning 1)))) | |
483 | (while | |
ad4888e4 RS |
484 | (and (not (eobp)) |
485 | ;; Stop at a pair of blank lines. | |
486 | (not (looking-at "\n\\s-*\n"))) | |
487 | ;; Skip a single blank line. | |
488 | (and (eolp) (forward-line)) | |
489 | (end-of-line) | |
490 | (skip-chars-backward "^\t\n") | |
491 | (if (and (>= (current-column) col) | |
492 | (looking-at "\\(\\sw\\|-\\)+$")) | |
493 | (let ((sym (intern-soft (match-string 0)))) | |
494 | (if (fboundp sym) | |
495 | (help-xref-button 0 'help-function sym)))) | |
043dcdee JPW |
496 | (forward-line)))))) |
497 | (set-syntax-table stab)) | |
f4ed5b19 MB |
498 | ;; Delete extraneous newlines at the end of the docstring |
499 | (goto-char (point-max)) | |
500 | (while (and (not (bobp)) (bolp)) | |
501 | (delete-char -1)) | |
478eb46b | 502 | (insert "\n") |
ea3da5b9 MR |
503 | (when (or help-xref-stack help-xref-forward-stack) |
504 | (insert "\n")) | |
f4ed5b19 | 505 | ;; Make a back-reference in this buffer if appropriate. |
89f5b33f | 506 | (when help-xref-stack |
f4ed5b19 | 507 | (help-insert-xref-button help-back-label 'help-back |
ea3da5b9 | 508 | (current-buffer))) |
95f731db NR |
509 | ;; Make a forward-reference in this buffer if appropriate. |
510 | (when help-xref-forward-stack | |
ea3da5b9 MR |
511 | (when help-xref-stack |
512 | (insert "\t")) | |
95f731db | 513 | (help-insert-xref-button help-forward-label 'help-forward |
ea3da5b9 MR |
514 | (current-buffer))) |
515 | (when (or help-xref-stack help-xref-forward-stack) | |
478eb46b | 516 | (insert "\n"))) |
f4ed5b19 MB |
517 | ;; View mode steals RET from us. |
518 | (set (make-local-variable 'minor-mode-overriding-map-alist) | |
410e58b5 | 519 | (list (cons 'view-mode help-xref-override-view-map))) |
f4ed5b19 MB |
520 | (set-buffer-modified-p old-modified)))) |
521 | ||
522 | ;;;###autoload | |
523 | (defun help-xref-button (match-number type &rest args) | |
524 | "Make a hyperlink for cross-reference text previously matched. | |
525 | MATCH-NUMBER is the subexpression of interest in the last matched | |
526 | regexp. TYPE is the type of button to use. Any remaining arguments are | |
527 | passed to the button's help-function when it is invoked. | |
528 | See `help-make-xrefs'." | |
529 | ;; Don't mung properties we've added specially in some instances. | |
530 | (unless (button-at (match-beginning match-number)) | |
531 | (make-text-button (match-beginning match-number) | |
532 | (match-end match-number) | |
533 | 'type type 'help-args args))) | |
534 | ||
535 | ;;;###autoload | |
536 | (defun help-insert-xref-button (string type &rest args) | |
537 | "Insert STRING and make a hyperlink from cross-reference text on it. | |
538 | TYPE is the type of button to use. Any remaining arguments are passed | |
539 | to the button's help-function when it is invoked. | |
540 | See `help-make-xrefs'." | |
541 | (unless (button-at (point)) | |
542 | (insert-text-button string 'type type 'help-args args))) | |
543 | ||
544 | ;;;###autoload | |
545 | (defun help-xref-on-pp (from to) | |
546 | "Add xrefs for symbols in `pp's output between FROM and TO." | |
22f5d492 SM |
547 | (if (> (- to from) 5000) nil |
548 | (with-syntax-table emacs-lisp-mode-syntax-table | |
549 | (save-excursion | |
550 | (save-restriction | |
551 | (narrow-to-region from to) | |
552 | (goto-char (point-min)) | |
553 | (condition-case nil | |
554 | (while (not (eobp)) | |
555 | (cond | |
556 | ((looking-at "\"") (forward-sexp 1)) | |
557 | ((looking-at "#<") (search-forward ">" nil 'move)) | |
558 | ((looking-at "\\(\\(\\sw\\|\\s_\\)+\\)") | |
559 | (let* ((sym (intern-soft (match-string 1))) | |
560 | (type (cond ((fboundp sym) 'help-function) | |
561 | ((or (memq sym '(t nil)) | |
562 | (keywordp sym)) | |
563 | nil) | |
e715d9b4 LT |
564 | ((and sym |
565 | (or (boundp sym) | |
566 | (get sym | |
567 | 'variable-documentation))) | |
22f5d492 SM |
568 | 'help-variable)))) |
569 | (when type (help-xref-button 1 type sym))) | |
570 | (goto-char (match-end 1))) | |
571 | (t (forward-char 1)))) | |
572 | (error nil))))))) | |
f4ed5b19 MB |
573 | |
574 | \f | |
575 | ;; Additional functions for (re-)creating types of help buffers. | |
576 | (defun help-xref-interned (symbol) | |
577 | "Follow a hyperlink which appeared to be an arbitrary interned SYMBOL. | |
89f5b33f | 578 | Both variable, function and face documentation are extracted into a single |
f4ed5b19 | 579 | help buffer." |
89f5b33f SM |
580 | (with-current-buffer (help-buffer) |
581 | ;; Push the previous item on the stack before clobbering the output buffer. | |
774784f6 | 582 | (help-setup-xref nil nil) |
89f5b33f SM |
583 | (let ((facedoc (when (facep symbol) |
584 | ;; Don't record the current entry in the stack. | |
585 | (setq help-xref-stack-item nil) | |
586 | (describe-face symbol))) | |
587 | (fdoc (when (fboundp symbol) | |
588 | ;; Don't record the current entry in the stack. | |
589 | (setq help-xref-stack-item nil) | |
590 | (describe-function symbol))) | |
e715d9b4 LT |
591 | (sdoc (when (or (boundp symbol) |
592 | (get symbol 'variable-documentation)) | |
89f5b33f SM |
593 | ;; Don't record the current entry in the stack. |
594 | (setq help-xref-stack-item nil) | |
595 | (describe-variable symbol)))) | |
596 | (cond | |
597 | (sdoc | |
598 | ;; We now have a help buffer on the variable. | |
599 | ;; Insert the function and face text before it. | |
ea127bf4 | 600 | (when (or fdoc facedoc) |
f4ed5b19 MB |
601 | (goto-char (point-min)) |
602 | (let ((inhibit-read-only t)) | |
603 | (when fdoc | |
89f5b33f | 604 | (insert fdoc "\n\n") |
ea127bf4 RS |
605 | (when facedoc |
606 | (insert (make-string 30 ?-) "\n\n" (symbol-name symbol) | |
89f5b33f SM |
607 | " is also a " "face." "\n\n"))) |
608 | (when facedoc | |
609 | (insert facedoc "\n\n")) | |
f4ed5b19 MB |
610 | (insert (make-string 30 ?-) "\n\n" (symbol-name symbol) |
611 | " is also a " "variable." "\n\n")) | |
89f5b33f SM |
612 | ;; Don't record the `describe-variable' item in the stack. |
613 | (setq help-xref-stack-item nil) | |
614 | (help-setup-xref (list #'help-xref-interned symbol) nil))) | |
615 | (fdoc | |
616 | ;; We now have a help buffer on the function. | |
617 | ;; Insert face text before it. | |
618 | (when facedoc | |
619 | (goto-char (point-max)) | |
620 | (let ((inhibit-read-only t)) | |
621 | (insert "\n\n" (make-string 30 ?-) "\n\n" (symbol-name symbol) | |
622 | " is also a " "face." "\n\n" facedoc)) | |
623 | ;; Don't record the `describe-function' item in the stack. | |
624 | (setq help-xref-stack-item nil) | |
625 | (help-setup-xref (list #'help-xref-interned symbol) nil))))))) | |
f4ed5b19 MB |
626 | |
627 | \f | |
410e58b5 | 628 | ;; Navigation/hyperlinking with xrefs |
f4ed5b19 MB |
629 | |
630 | (defun help-xref-go-back (buffer) | |
631 | "From BUFFER, go back to previous help buffer text using `help-xref-stack'." | |
632 | (let (item position method args) | |
633 | (with-current-buffer buffer | |
95f731db | 634 | (push (cons (point) help-xref-stack-item) help-xref-forward-stack) |
f4ed5b19 | 635 | (when help-xref-stack |
f4ed5b19 | 636 | (setq item (pop help-xref-stack) |
89f5b33f SM |
637 | ;; Clear the current item so that it won't get pushed |
638 | ;; by the function we're about to call. TODO: We could also | |
639 | ;; push it onto a "forward" stack and add a `forw' button. | |
640 | help-xref-stack-item nil | |
f4ed5b19 MB |
641 | position (car item) |
642 | method (cadr item) | |
643 | args (cddr item)))) | |
644 | (apply method args) | |
77144ebc RS |
645 | (with-current-buffer buffer |
646 | (if (get-buffer-window buffer) | |
647 | (set-window-point (get-buffer-window buffer) position) | |
648 | (goto-char position))))) | |
f4ed5b19 | 649 | |
95f731db NR |
650 | (defun help-xref-go-forward (buffer) |
651 | "From BUFFER, go forward to next help buffer." | |
652 | (let (item position method args) | |
653 | (with-current-buffer buffer | |
654 | (push (cons (point) help-xref-stack-item) help-xref-stack) | |
655 | (when help-xref-forward-stack | |
656 | (setq item (pop help-xref-forward-stack) | |
657 | ;; Clear the current item so that it won't get pushed | |
658 | ;; by the function we're about to call. TODO: We could also | |
659 | ;; push it onto a "forward" stack and add a `forw' button. | |
660 | help-xref-stack-item nil | |
661 | position (car item) | |
662 | method (cadr item) | |
663 | args (cddr item)))) | |
664 | (apply method args) | |
665 | (with-current-buffer buffer | |
666 | (if (get-buffer-window buffer) | |
667 | (set-window-point (get-buffer-window buffer) position) | |
668 | (goto-char position))))) | |
669 | ||
f4ed5b19 | 670 | (defun help-go-back () |
933cd61e | 671 | "Go back to previous topic in this help buffer." |
f4ed5b19 | 672 | (interactive) |
933cd61e SM |
673 | (if help-xref-stack |
674 | (help-xref-go-back (current-buffer)) | |
fdeadcd1 | 675 | (error "No previous help buffer"))) |
95f731db NR |
676 | |
677 | (defun help-go-forward () | |
678 | "Go back to next topic in this help buffer." | |
679 | (interactive) | |
680 | (if help-xref-forward-stack | |
681 | (help-xref-go-forward (current-buffer)) | |
682 | (error "No next help buffer"))) | |
f4ed5b19 MB |
683 | |
684 | (defun help-do-xref (pos function args) | |
685 | "Call the help cross-reference function FUNCTION with args ARGS. | |
686 | Things are set up properly so that the resulting help-buffer has | |
687 | a proper [back] button." | |
f4ed5b19 MB |
688 | ;; There is a reference at point. Follow it. |
689 | (let ((help-xref-following t)) | |
690 | (apply function args))) | |
691 | ||
8a31f813 LT |
692 | ;; The doc string is meant to explain what buttons do. |
693 | (defun help-follow-mouse () | |
694 | "Follow the cross-reference that you click on." | |
695 | (interactive) | |
696 | (error "No cross-reference here")) | |
697 | ||
698 | ;; The doc string is meant to explain what buttons do. | |
699 | (defun help-follow () | |
700 | "Follow cross-reference at point. | |
f4ed5b19 MB |
701 | |
702 | For the cross-reference format, see `help-make-xrefs'." | |
8a31f813 LT |
703 | (interactive) |
704 | (error "No cross-reference here")) | |
705 | ||
706 | (defun help-follow-symbol (&optional pos) | |
707 | "In help buffer, show docs for symbol at POS, defaulting to point. | |
708 | Show all docs for that symbol as either a variable, function or face." | |
f4ed5b19 MB |
709 | (interactive "d") |
710 | (unless pos | |
711 | (setq pos (point))) | |
8a31f813 LT |
712 | ;; check if the symbol under point is a function, variable or face |
713 | (let ((sym | |
714 | (intern | |
715 | (save-excursion | |
716 | (goto-char pos) (skip-syntax-backward "w_") | |
717 | (buffer-substring (point) | |
718 | (progn (skip-syntax-forward "w_") | |
719 | (point))))))) | |
720 | (when (or (boundp sym) | |
721 | (get sym 'variable-documentation) | |
722 | (fboundp sym) (facep sym)) | |
723 | (help-do-xref pos #'help-xref-interned (list sym))))) | |
f4ed5b19 | 724 | |
ee90fe92 NR |
725 | (defun help-insert-string (string) |
726 | "Insert STRING to the help buffer and install xref info for it. | |
727 | This function can be used to restore the old contents of the help buffer | |
728 | when going back to the previous topic in the xref stack. It is needed | |
729 | in case when it is impossible to recompute the old contents of the | |
730 | help buffer by other means." | |
731 | (setq help-xref-stack-item (list #'help-insert-string string)) | |
732 | (with-output-to-temp-buffer (help-buffer) | |
733 | (insert string))) | |
f4ed5b19 MB |
734 | |
735 | (provide 'help-mode) | |
736 | ||
65dd6275 | 737 | ;; arch-tag: 850954ae-3725-4cb4-8e91-0bf6d52d6b0b |
f4ed5b19 | 738 | ;;; help-mode.el ends here |