Commit | Line | Data |
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55535639 | 1 | ;;; electric.el --- window maker and Command loop for `electric' modes |
c0274f38 | 2 | |
73b0cd50 | 3 | ;; Copyright (C) 1985-1986, 1995, 2001-2011 Free Software Foundation, Inc. |
9750e079 | 4 | |
e5167999 ER |
5 | ;; Author: K. Shane Hartman |
6 | ;; Maintainer: FSF | |
fd7fa35a | 7 | ;; Keywords: extensions |
e5167999 | 8 | |
0d20f9a0 JB |
9 | ;; This file is part of GNU Emacs. |
10 | ||
eb3fa2cf | 11 | ;; GNU Emacs is free software: you can redistribute it and/or modify |
0d20f9a0 | 12 | ;; it under the terms of the GNU General Public License as published by |
eb3fa2cf GM |
13 | ;; the Free Software Foundation, either version 3 of the License, or |
14 | ;; (at your option) any later version. | |
0d20f9a0 JB |
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 | |
eb3fa2cf | 22 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. |
0d20f9a0 | 23 | |
c8472948 | 24 | ;;; Commentary: |
0d20f9a0 | 25 | |
3b843809 SM |
26 | ;; "Electric" has been used in Emacs to refer to different things. |
27 | ;; Among them: | |
28 | ;; | |
29 | ;; - electric modes and buffers: modes that typically pop-up in a modal kind of | |
30 | ;; way a transient buffer that automatically disappears as soon as the user | |
31 | ;; is done with it. | |
32 | ;; | |
33 | ;; - electric keys: self inserting keys which additionally perform some side | |
34 | ;; operation which happens to be often convenient at that time. Examples of | |
35 | ;; such side operations are: reindenting code, inserting a newline, | |
36 | ;; ... auto-fill-mode and abbrev-mode can be considered as built-in forms of | |
37 | ;; electric key behavior. | |
0d20f9a0 | 38 | |
c8472948 ER |
39 | ;;; Code: |
40 | ||
3b843809 SM |
41 | (eval-when-compile (require 'cl)) |
42 | ||
0d20f9a0 | 43 | ;; This loop is the guts for non-standard modes which retain control |
f135afd3 RS |
44 | ;; until some event occurs. It is a `do-forever', the only way out is |
45 | ;; to throw. It assumes that you have set up the keymap, window, and | |
0d20f9a0 JB |
46 | ;; everything else: all it does is read commands and execute them - |
47 | ;; providing error messages should one occur (if there is no loop | |
48 | ;; function - which see). The required argument is a tag which should | |
f135afd3 RS |
49 | ;; expect a value of nil if the user decides to punt. The second |
50 | ;; argument is the prompt to be used: if nil, use "->", if 'noprompt, | |
51 | ;; don't use a prompt, if a string, use that string as prompt, and if | |
52 | ;; a function of no variable, it will be evaluated in every iteration | |
53 | ;; of the loop and its return value, which can be nil, 'noprompt or a | |
54 | ;; string, will be used as prompt. Given third argument non-nil, it | |
55 | ;; INHIBITS quitting unless the user types C-g at toplevel. This is | |
56 | ;; so user can do things like C-u C-g and not get thrown out. Fourth | |
57 | ;; argument, if non-nil, should be a function of two arguments which | |
58 | ;; is called after every command is executed. The fifth argument, if | |
59 | ;; provided, is the state variable for the function. If the | |
0d20f9a0 JB |
60 | ;; loop-function gets an error, the loop will abort WITHOUT throwing |
61 | ;; (moral: use unwind-protect around call to this function for any | |
62 | ;; critical stuff). The second argument for the loop function is the | |
63 | ;; conditions for any error that occurred or nil if none. | |
64 | ||
65 | (defun Electric-command-loop (return-tag | |
66 | &optional prompt inhibit-quit | |
67 | loop-function loop-state) | |
f135afd3 | 68 | |
71296446 JB |
69 | (let (cmd |
70 | (err nil) | |
f135afd3 | 71 | (prompt-string prompt)) |
0d20f9a0 | 72 | (while t |
ba5bf5f0 | 73 | (if (functionp prompt) |
f135afd3 RS |
74 | (setq prompt-string (funcall prompt))) |
75 | (if (not (stringp prompt-string)) | |
ba5bf5f0 | 76 | (setq prompt-string (unless (eq prompt-string 'noprompt) "->"))) |
f135afd3 | 77 | (setq cmd (read-key-sequence prompt-string)) |
8989a920 | 78 | (setq last-command-event (aref cmd (1- (length cmd))) |
f867d8d3 | 79 | this-command (key-binding cmd t) |
0d20f9a0 | 80 | cmd this-command) |
f867d8d3 RS |
81 | ;; This makes universal-argument-other-key work. |
82 | (setq universal-argument-num-events 0) | |
0d20f9a0 | 83 | (if (or (prog1 quit-flag (setq quit-flag nil)) |
1e4bd40d | 84 | (eq last-input-event ?\C-g)) |
dbc4e1c1 | 85 | (progn (setq unread-command-events nil |
0d20f9a0 JB |
86 | prefix-arg nil) |
87 | ;; If it wasn't cancelling a prefix character, then quit. | |
88 | (if (or (= (length (this-command-keys)) 1) | |
89 | (not inhibit-quit)) ; safety | |
90 | (progn (ding) | |
91 | (message "Quit") | |
92 | (throw return-tag nil)) | |
93 | (setq cmd nil)))) | |
94 | (setq current-prefix-arg prefix-arg) | |
95 | (if cmd | |
96 | (condition-case conditions | |
97 | (progn (command-execute cmd) | |
17c17ec9 | 98 | (setq last-command this-command) |
0d20f9a0 | 99 | (if (or (prog1 quit-flag (setq quit-flag nil)) |
1e4bd40d | 100 | (eq last-input-event ?\C-g)) |
dbc4e1c1 | 101 | (progn (setq unread-command-events nil) |
0d20f9a0 JB |
102 | (if (not inhibit-quit) |
103 | (progn (ding) | |
104 | (message "Quit") | |
105 | (throw return-tag nil)) | |
106 | (ding))))) | |
107 | (buffer-read-only (if loop-function | |
108 | (setq err conditions) | |
109 | (ding) | |
110 | (message "Buffer is read-only") | |
111 | (sit-for 2))) | |
112 | (beginning-of-buffer (if loop-function | |
113 | (setq err conditions) | |
114 | (ding) | |
115 | (message "Beginning of Buffer") | |
116 | (sit-for 2))) | |
117 | (end-of-buffer (if loop-function | |
118 | (setq err conditions) | |
119 | (ding) | |
120 | (message "End of Buffer") | |
121 | (sit-for 2))) | |
122 | (error (if loop-function | |
123 | (setq err conditions) | |
124 | (ding) | |
125 | (message "Error: %s" | |
126 | (if (eq (car conditions) 'error) | |
127 | (car (cdr conditions)) | |
128 | (prin1-to-string conditions))) | |
129 | (sit-for 2)))) | |
130 | (ding)) | |
131 | (if loop-function (funcall loop-function loop-state err)))) | |
132 | (ding) | |
133 | (throw return-tag nil)) | |
134 | ||
71296446 | 135 | ;; This function is like pop-to-buffer, sort of. |
0d20f9a0 JB |
136 | ;; The algorithm is |
137 | ;; If there is a window displaying buffer | |
138 | ;; Select it | |
139 | ;; Else if there is only one window | |
140 | ;; Split it, selecting the window on the bottom with height being | |
141 | ;; the lesser of max-height (if non-nil) and the number of lines in | |
142 | ;; the buffer to be displayed subject to window-min-height constraint. | |
143 | ;; Else | |
144 | ;; Switch to buffer in the current window. | |
145 | ;; | |
146 | ;; Then if max-height is nil, and not all of the lines in the buffer | |
f98955ea | 147 | ;; are displayed, grab the whole frame. |
0d20f9a0 JB |
148 | ;; |
149 | ;; Returns selected window on buffer positioned at point-min. | |
150 | ||
151 | (defun Electric-pop-up-window (buffer &optional max-height) | |
152 | (let* ((win (or (get-buffer-window buffer) (selected-window))) | |
153 | (buf (get-buffer buffer)) | |
154 | (one-window (one-window-p t)) | |
155 | (pop-up-windows t) | |
c45c149c | 156 | (pop-up-frames nil)) |
0d20f9a0 JB |
157 | (if (not buf) |
158 | (error "Buffer %s does not exist" buffer) | |
0d20f9a0 JB |
159 | (cond ((and (eq (window-buffer win) buf)) |
160 | (select-window win)) | |
161 | (one-window | |
0d20f9a0 | 162 | (pop-to-buffer buffer) |
c45c149c | 163 | (setq win (selected-window))) |
0d20f9a0 JB |
164 | (t |
165 | (switch-to-buffer buf))) | |
48238d1d | 166 | ;; Don't shrink the window, but expand it if necessary. |
0d20f9a0 | 167 | (goto-char (point-min)) |
0e87e61e | 168 | (unless (= (point-max) (window-end win t)) |
48238d1d | 169 | (fit-window-to-buffer win max-height)) |
0d20f9a0 | 170 | win))) |
49116ac0 | 171 | |
3b843809 SM |
172 | ;;; Electric keys. |
173 | ||
174 | (defgroup electricity () | |
175 | "Electric behavior for self inserting keys." | |
176 | :group 'editing) | |
177 | ||
7100ff98 SM |
178 | (defun electric--after-char-pos () |
179 | "Return the position after the char we just inserted. | |
180 | Returns nil when we can't find this char." | |
181 | (let ((pos (point))) | |
182 | (when (or (eq (char-before) last-command-event) ;; Sanity check. | |
183 | (save-excursion | |
184 | (or (progn (skip-chars-backward " \t") | |
185 | (setq pos (point)) | |
186 | (eq (char-before) last-command-event)) | |
187 | (progn (skip-chars-backward " \n\t") | |
188 | (setq pos (point)) | |
189 | (eq (char-before) last-command-event))))) | |
190 | pos))) | |
191 | ||
3b843809 SM |
192 | ;; Electric indentation. |
193 | ||
2122161f SM |
194 | ;; Autoloading variables is generally undesirable, but major modes |
195 | ;; should usually set this variable by adding elements to the default | |
196 | ;; value, which only works well if the variable is preloaded. | |
197 | ;;;###autoload | |
3b843809 SM |
198 | (defvar electric-indent-chars '(?\n) |
199 | "Characters that should cause automatic reindentation.") | |
200 | ||
201 | (defun electric-indent-post-self-insert-function () | |
202 | ;; FIXME: This reindents the current line, but what we really want instead is | |
203 | ;; to reindent the whole affected text. That's the current line for simple | |
204 | ;; cases, but not all cases. We do take care of the newline case in an | |
205 | ;; ad-hoc fashion, but there are still missing cases such as the case of | |
206 | ;; electric-pair-mode wrapping a region with a pair of parens. | |
207 | ;; There might be a way to get it working by analyzing buffer-undo-list, but | |
208 | ;; it looks challenging. | |
7100ff98 SM |
209 | (let (pos) |
210 | (when (and (memq last-command-event electric-indent-chars) | |
211 | ;; Don't reindent while inserting spaces at beginning of line. | |
212 | (or (not (memq last-command-event '(?\s ?\t))) | |
213 | (save-excursion (skip-chars-backward " \t") (not (bolp)))) | |
214 | (setq pos (electric--after-char-pos)) | |
215 | ;; Not in a string or comment. | |
216 | (not (nth 8 (save-excursion (syntax-ppss pos))))) | |
217 | ;; For newline, we want to reindent both lines and basically behave like | |
218 | ;; reindent-then-newline-and-indent (whose code we hence copied). | |
a733fc37 | 219 | (when (< (1- pos) (line-beginning-position)) |
7100ff98 SM |
220 | (let ((before (copy-marker (1- pos) t))) |
221 | (save-excursion | |
a733fc37 | 222 | (unless (memq indent-line-function |
74a10be5 SM |
223 | '(indent-relative indent-to-left-margin |
224 | indent-relative-maybe)) | |
a733fc37 SM |
225 | ;; Don't reindent the previous line if the indentation function |
226 | ;; is not a real one. | |
227 | (goto-char before) | |
228 | (indent-according-to-mode)) | |
7100ff98 SM |
229 | ;; We are at EOL before the call to indent-according-to-mode, and |
230 | ;; after it we usually are as well, but not always. We tried to | |
231 | ;; address it with `save-excursion' but that uses a normal marker | |
232 | ;; whereas we need `move after insertion', so we do the | |
233 | ;; save/restore by hand. | |
234 | (goto-char before) | |
235 | ;; Remove the trailing whitespace after indentation because | |
236 | ;; indentation may (re)introduce the whitespace. | |
237 | (delete-horizontal-space t)))) | |
74a10be5 SM |
238 | (unless (memq indent-line-function '(indent-to-left-margin)) |
239 | (indent-according-to-mode))))) | |
3b843809 SM |
240 | |
241 | ;;;###autoload | |
242 | (define-minor-mode electric-indent-mode | |
243 | "Automatically reindent lines of code when inserting particular chars. | |
244 | `electric-indent-chars' specifies the set of chars that should cause reindentation." | |
245 | :global t | |
246 | :group 'electricity | |
247 | (if electric-indent-mode | |
248 | (add-hook 'post-self-insert-hook | |
249 | #'electric-indent-post-self-insert-function) | |
250 | (remove-hook 'post-self-insert-hook | |
7100ff98 SM |
251 | #'electric-indent-post-self-insert-function)) |
252 | ;; FIXME: electric-indent-mode and electric-layout-mode interact | |
253 | ;; in non-trivial ways. It turns out that electric-indent-mode works | |
254 | ;; better if it is run *after* electric-layout-mode's hook. | |
255 | (when (memq #'electric-layout-post-self-insert-function | |
256 | (memq #'electric-indent-post-self-insert-function | |
257 | (default-value 'post-self-insert-hook))) | |
258 | (remove-hook 'post-self-insert-hook | |
259 | #'electric-layout-post-self-insert-function) | |
260 | (add-hook 'post-self-insert-hook | |
261 | #'electric-layout-post-self-insert-function))) | |
3b843809 SM |
262 | |
263 | ;; Electric pairing. | |
264 | ||
c51bb5d2 SM |
265 | (defcustom electric-pair-pairs |
266 | '((?\" . ?\")) | |
267 | "Alist of pairs that should be used regardless of major mode." | |
268 | :type '(repeat (cons character character))) | |
269 | ||
3b843809 SM |
270 | (defcustom electric-pair-skip-self t |
271 | "If non-nil, skip char instead of inserting a second closing paren. | |
272 | When inserting a closing paren character right before the same character, | |
273 | just skip that character instead, so that hitting ( followed by ) results | |
274 | in \"()\" rather than \"())\". | |
275 | This can be convenient for people who find it easier to hit ) than C-f." | |
276 | :type 'boolean) | |
277 | ||
278 | (defun electric-pair-post-self-insert-function () | |
279 | (let* ((syntax (and (eq (char-before) last-command-event) ; Sanity check. | |
c51bb5d2 SM |
280 | (let ((x (assq last-command-event electric-pair-pairs))) |
281 | (cond | |
282 | (x (if (eq (car x) (cdr x)) ?\" ?\()) | |
283 | ((rassq last-command-event electric-pair-pairs) ?\)) | |
284 | (t (char-syntax last-command-event)))))) | |
3b843809 SM |
285 | ;; FIXME: when inserting the closer, we should maybe use |
286 | ;; self-insert-command, although it may prove tricky running | |
287 | ;; post-self-insert-hook recursively, and we wouldn't want to trigger | |
288 | ;; blink-matching-open. | |
289 | (closer (if (eq syntax ?\() | |
c51bb5d2 SM |
290 | (cdr (or (assq last-command-event electric-pair-pairs) |
291 | (aref (syntax-table) last-command-event))) | |
3b843809 SM |
292 | last-command-event))) |
293 | (cond | |
294 | ;; Wrap a pair around the active region. | |
295 | ((and (memq syntax '(?\( ?\" ?\$)) (use-region-p)) | |
296 | (if (> (mark) (point)) | |
297 | (goto-char (mark)) | |
298 | ;; We already inserted the open-paren but at the end of the region, | |
299 | ;; so we have to remove it and start over. | |
300 | (delete-char -1) | |
301 | (save-excursion | |
302 | (goto-char (mark)) | |
303 | (insert last-command-event))) | |
304 | (insert closer)) | |
305 | ;; Backslash-escaped: no pairing, no skipping. | |
306 | ((save-excursion | |
307 | (goto-char (1- (point))) | |
308 | (not (zerop (% (skip-syntax-backward "\\") 2)))) | |
309 | nil) | |
310 | ;; Skip self. | |
311 | ((and (memq syntax '(?\) ?\" ?\$)) | |
312 | electric-pair-skip-self | |
313 | (eq (char-after) last-command-event)) | |
314 | ;; This is too late: rather than insert&delete we'd want to only skip (or | |
315 | ;; insert in overwrite mode). The difference is in what goes in the | |
316 | ;; undo-log and in the intermediate state which might be visible to other | |
317 | ;; post-self-insert-hook. We'll just have to live with it for now. | |
318 | (delete-char 1)) | |
319 | ;; Insert matching pair. | |
320 | ((not (or (not (memq syntax `(?\( ?\" ?\$))) | |
321 | overwrite-mode | |
322 | ;; I find it more often preferable not to pair when the | |
323 | ;; same char is next. | |
324 | (eq last-command-event (char-after)) | |
325 | (eq last-command-event (char-before (1- (point)))) | |
326 | ;; I also find it often preferable not to pair next to a word. | |
327 | (eq (char-syntax (following-char)) ?w))) | |
328 | (save-excursion (insert closer)))))) | |
329 | ||
330 | ;;;###autoload | |
331 | (define-minor-mode electric-pair-mode | |
332 | "Automatically pair-up parens when inserting an open paren." | |
333 | :global t | |
334 | :group 'electricity | |
335 | (if electric-pair-mode | |
336 | (add-hook 'post-self-insert-hook | |
337 | #'electric-pair-post-self-insert-function) | |
338 | (remove-hook 'post-self-insert-hook | |
339 | #'electric-pair-post-self-insert-function))) | |
7100ff98 SM |
340 | |
341 | ;; Automatically add newlines after/before/around some chars. | |
342 | ||
343 | (defvar electric-layout-rules '() | |
344 | "List of rules saying where to automatically insert newlines. | |
345 | Each rule has the form (CHAR . WHERE) where CHAR is the char | |
346 | that was just inserted and WHERE specifies where to insert newlines | |
347 | and can be: nil, `before', `after', `around', or a function that returns | |
348 | one of those symbols.") | |
349 | ||
350 | (defun electric-layout-post-self-insert-function () | |
351 | (let* ((rule (cdr (assq last-command-event electric-layout-rules))) | |
352 | pos) | |
353 | (when (and rule | |
354 | (setq pos (electric--after-char-pos)) | |
355 | ;; Not in a string or comment. | |
356 | (not (nth 8 (save-excursion (syntax-ppss pos))))) | |
357 | (let ((end (copy-marker (point) t))) | |
358 | (goto-char pos) | |
359 | (case (if (functionp rule) (funcall rule) rule) | |
360 | ;; FIXME: we used `newline' down here which called | |
361 | ;; self-insert-command and ran post-self-insert-hook recursively. | |
362 | ;; It happened to make electric-indent-mode work automatically with | |
363 | ;; electric-layout-mode (at the cost of re-indenting lines | |
364 | ;; multiple times), but I'm not sure it's what we want. | |
c51bb5d2 SM |
365 | (before (goto-char (1- pos)) (skip-chars-backward " \t") |
366 | (unless (bolp) (insert "\n"))) | |
367 | (after (insert "\n")) ; FIXME: check eolp before inserting \n? | |
368 | (around (save-excursion | |
369 | (goto-char (1- pos)) (skip-chars-backward " \t") | |
370 | (unless (bolp) (insert "\n"))) | |
371 | (insert "\n"))) ; FIXME: check eolp before inserting \n? | |
7100ff98 SM |
372 | (goto-char end))))) |
373 | ||
374 | ;;;###autoload | |
375 | (define-minor-mode electric-layout-mode | |
376 | "Automatically insert newlines around some chars." | |
377 | :global t | |
378 | :group 'electricity | |
379 | (if electric-layout-mode | |
380 | (add-hook 'post-self-insert-hook | |
381 | #'electric-layout-post-self-insert-function) | |
382 | (remove-hook 'post-self-insert-hook | |
383 | #'electric-layout-post-self-insert-function))) | |
384 | ||
c0274f38 ER |
385 | (provide 'electric) |
386 | ||
c8472948 | 387 | ;;; electric.el ends here |