Commit | Line | Data |
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55535639 | 1 | ;;; electric.el --- window maker and Command loop for `electric' modes |
c0274f38 | 2 | |
ba318903 | 3 | ;; Copyright (C) 1985-1986, 1995, 2001-2014 Free Software Foundation, |
ab422c4d | 4 | ;; Inc. |
9750e079 | 5 | |
e5167999 | 6 | ;; Author: K. Shane Hartman |
34dc21db | 7 | ;; Maintainer: emacs-devel@gnu.org |
fd7fa35a | 8 | ;; Keywords: extensions |
e5167999 | 9 | |
0d20f9a0 JB |
10 | ;; This file is part of GNU Emacs. |
11 | ||
eb3fa2cf | 12 | ;; GNU Emacs is free software: you can redistribute it and/or modify |
0d20f9a0 | 13 | ;; it under the terms of the GNU General Public License as published by |
eb3fa2cf GM |
14 | ;; the Free Software Foundation, either version 3 of the License, or |
15 | ;; (at your option) any later version. | |
0d20f9a0 JB |
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 | |
eb3fa2cf | 23 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. |
0d20f9a0 | 24 | |
c8472948 | 25 | ;;; Commentary: |
0d20f9a0 | 26 | |
3b843809 SM |
27 | ;; "Electric" has been used in Emacs to refer to different things. |
28 | ;; Among them: | |
29 | ;; | |
30 | ;; - electric modes and buffers: modes that typically pop-up in a modal kind of | |
31 | ;; way a transient buffer that automatically disappears as soon as the user | |
32 | ;; is done with it. | |
33 | ;; | |
34 | ;; - electric keys: self inserting keys which additionally perform some side | |
35 | ;; operation which happens to be often convenient at that time. Examples of | |
36 | ;; such side operations are: reindenting code, inserting a newline, | |
37 | ;; ... auto-fill-mode and abbrev-mode can be considered as built-in forms of | |
38 | ;; electric key behavior. | |
0d20f9a0 | 39 | |
c8472948 ER |
40 | ;;; Code: |
41 | ||
0d20f9a0 | 42 | ;; This loop is the guts for non-standard modes which retain control |
f135afd3 RS |
43 | ;; until some event occurs. It is a `do-forever', the only way out is |
44 | ;; to throw. It assumes that you have set up the keymap, window, and | |
0d20f9a0 JB |
45 | ;; everything else: all it does is read commands and execute them - |
46 | ;; providing error messages should one occur (if there is no loop | |
47 | ;; function - which see). The required argument is a tag which should | |
f135afd3 RS |
48 | ;; expect a value of nil if the user decides to punt. The second |
49 | ;; argument is the prompt to be used: if nil, use "->", if 'noprompt, | |
50 | ;; don't use a prompt, if a string, use that string as prompt, and if | |
51 | ;; a function of no variable, it will be evaluated in every iteration | |
52 | ;; of the loop and its return value, which can be nil, 'noprompt or a | |
53 | ;; string, will be used as prompt. Given third argument non-nil, it | |
54 | ;; INHIBITS quitting unless the user types C-g at toplevel. This is | |
55 | ;; so user can do things like C-u C-g and not get thrown out. Fourth | |
56 | ;; argument, if non-nil, should be a function of two arguments which | |
57 | ;; is called after every command is executed. The fifth argument, if | |
58 | ;; provided, is the state variable for the function. If the | |
0d20f9a0 JB |
59 | ;; loop-function gets an error, the loop will abort WITHOUT throwing |
60 | ;; (moral: use unwind-protect around call to this function for any | |
61 | ;; critical stuff). The second argument for the loop function is the | |
62 | ;; conditions for any error that occurred or nil if none. | |
63 | ||
64 | (defun Electric-command-loop (return-tag | |
06b60517 | 65 | &optional prompt inhibit-quitting |
0d20f9a0 | 66 | loop-function loop-state) |
f135afd3 | 67 | |
71296446 JB |
68 | (let (cmd |
69 | (err nil) | |
06b60517 | 70 | (inhibit-quit inhibit-quitting) |
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 JB |
80 | cmd this-command) |
81 | (if (or (prog1 quit-flag (setq quit-flag nil)) | |
1e4bd40d | 82 | (eq last-input-event ?\C-g)) |
dbc4e1c1 | 83 | (progn (setq unread-command-events nil |
0d20f9a0 | 84 | prefix-arg nil) |
c80e3b4a | 85 | ;; If it wasn't canceling a prefix character, then quit. |
0d20f9a0 JB |
86 | (if (or (= (length (this-command-keys)) 1) |
87 | (not inhibit-quit)) ; safety | |
88 | (progn (ding) | |
89 | (message "Quit") | |
90 | (throw return-tag nil)) | |
91 | (setq cmd nil)))) | |
92 | (setq current-prefix-arg prefix-arg) | |
93 | (if cmd | |
94 | (condition-case conditions | |
95 | (progn (command-execute cmd) | |
17c17ec9 | 96 | (setq last-command this-command) |
0d20f9a0 | 97 | (if (or (prog1 quit-flag (setq quit-flag nil)) |
1e4bd40d | 98 | (eq last-input-event ?\C-g)) |
dbc4e1c1 | 99 | (progn (setq unread-command-events nil) |
0d20f9a0 JB |
100 | (if (not inhibit-quit) |
101 | (progn (ding) | |
102 | (message "Quit") | |
103 | (throw return-tag nil)) | |
104 | (ding))))) | |
105 | (buffer-read-only (if loop-function | |
106 | (setq err conditions) | |
107 | (ding) | |
108 | (message "Buffer is read-only") | |
109 | (sit-for 2))) | |
110 | (beginning-of-buffer (if loop-function | |
111 | (setq err conditions) | |
112 | (ding) | |
113 | (message "Beginning of Buffer") | |
114 | (sit-for 2))) | |
115 | (end-of-buffer (if loop-function | |
116 | (setq err conditions) | |
117 | (ding) | |
118 | (message "End of Buffer") | |
119 | (sit-for 2))) | |
120 | (error (if loop-function | |
121 | (setq err conditions) | |
122 | (ding) | |
123 | (message "Error: %s" | |
124 | (if (eq (car conditions) 'error) | |
125 | (car (cdr conditions)) | |
126 | (prin1-to-string conditions))) | |
127 | (sit-for 2)))) | |
128 | (ding)) | |
129 | (if loop-function (funcall loop-function loop-state err)))) | |
130 | (ding) | |
131 | (throw return-tag nil)) | |
132 | ||
71296446 | 133 | ;; This function is like pop-to-buffer, sort of. |
0d20f9a0 JB |
134 | ;; The algorithm is |
135 | ;; If there is a window displaying buffer | |
136 | ;; Select it | |
137 | ;; Else if there is only one window | |
138 | ;; Split it, selecting the window on the bottom with height being | |
139 | ;; the lesser of max-height (if non-nil) and the number of lines in | |
140 | ;; the buffer to be displayed subject to window-min-height constraint. | |
141 | ;; Else | |
142 | ;; Switch to buffer in the current window. | |
143 | ;; | |
144 | ;; Then if max-height is nil, and not all of the lines in the buffer | |
f98955ea | 145 | ;; are displayed, grab the whole frame. |
0d20f9a0 JB |
146 | ;; |
147 | ;; Returns selected window on buffer positioned at point-min. | |
148 | ||
149 | (defun Electric-pop-up-window (buffer &optional max-height) | |
150 | (let* ((win (or (get-buffer-window buffer) (selected-window))) | |
151 | (buf (get-buffer buffer)) | |
152 | (one-window (one-window-p t)) | |
153 | (pop-up-windows t) | |
c45c149c | 154 | (pop-up-frames nil)) |
0d20f9a0 JB |
155 | (if (not buf) |
156 | (error "Buffer %s does not exist" buffer) | |
0d20f9a0 JB |
157 | (cond ((and (eq (window-buffer win) buf)) |
158 | (select-window win)) | |
159 | (one-window | |
0d20f9a0 | 160 | (pop-to-buffer buffer) |
c45c149c | 161 | (setq win (selected-window))) |
0d20f9a0 JB |
162 | (t |
163 | (switch-to-buffer buf))) | |
48238d1d | 164 | ;; Don't shrink the window, but expand it if necessary. |
0d20f9a0 | 165 | (goto-char (point-min)) |
0e87e61e | 166 | (unless (= (point-max) (window-end win t)) |
48238d1d | 167 | (fit-window-to-buffer win max-height)) |
0d20f9a0 | 168 | win))) |
49116ac0 | 169 | |
3b843809 SM |
170 | ;;; Electric keys. |
171 | ||
172 | (defgroup electricity () | |
173 | "Electric behavior for self inserting keys." | |
174 | :group 'editing) | |
175 | ||
7100ff98 SM |
176 | (defun electric--after-char-pos () |
177 | "Return the position after the char we just inserted. | |
178 | Returns nil when we can't find this char." | |
179 | (let ((pos (point))) | |
180 | (when (or (eq (char-before) last-command-event) ;; Sanity check. | |
181 | (save-excursion | |
182 | (or (progn (skip-chars-backward " \t") | |
183 | (setq pos (point)) | |
184 | (eq (char-before) last-command-event)) | |
185 | (progn (skip-chars-backward " \n\t") | |
186 | (setq pos (point)) | |
187 | (eq (char-before) last-command-event))))) | |
188 | pos))) | |
189 | ||
3b8d5131 JT |
190 | (defun electric--sort-post-self-insertion-hook () |
191 | "Ensure order of electric functions in `post-self-insertion-hook'. | |
192 | ||
193 | Hooks in this variable interact in non-trivial ways, so a | |
194 | relative order must be maintained within it." | |
195 | (setq-default post-self-insert-hook | |
196 | (sort (default-value 'post-self-insert-hook) | |
197 | #'(lambda (fn1 fn2) | |
198 | (< (or (get fn1 'priority) 0) | |
199 | (or (get fn2 'priority) 0)))))) | |
200 | ||
2abb4e65 | 201 | ;;; Electric indentation. |
3b843809 | 202 | |
2122161f SM |
203 | ;; Autoloading variables is generally undesirable, but major modes |
204 | ;; should usually set this variable by adding elements to the default | |
205 | ;; value, which only works well if the variable is preloaded. | |
206 | ;;;###autoload | |
3b843809 | 207 | (defvar electric-indent-chars '(?\n) |
6f5e57e7 SM |
208 | "Characters that should cause automatic reindentation.") |
209 | ||
210 | (defvar electric-indent-functions nil | |
211 | "Special hook run to decide whether to auto-indent. | |
212 | Each function is called with one argument (the inserted char), with | |
213 | point right after that char, and it should return t to cause indentation, | |
214 | `no-indent' to prevent indentation or nil to let other functions decide.") | |
3b843809 | 215 | |
2abb4e65 SM |
216 | (defvar-local electric-indent-inhibit nil |
217 | "If non-nil, reindentation is not appropriate for this buffer. | |
218 | This should be set by major modes such as `python-mode' since | |
219 | Python does not lend itself to fully automatic indentation.") | |
220 | ||
a35287ea SM |
221 | (defvar electric-indent-functions-without-reindent |
222 | '(indent-relative indent-to-left-margin indent-relative-maybe | |
c8481b1b | 223 | py-indent-line coffee-indent-line org-indent-line yaml-indent-line |
e6025d72 SM |
224 | haskell-indentation-indent-line haskell-indent-cycle haskell-simple-indent |
225 | yaml-indent-line) | |
a35287ea SM |
226 | "List of indent functions that can't reindent. |
227 | If `line-indent-function' is one of those, then `electric-indent-mode' will | |
228 | not try to reindent lines. It is normally better to make the major | |
229 | mode set `electric-indent-inhibit', but this can be used as a workaround.") | |
230 | ||
3b843809 | 231 | (defun electric-indent-post-self-insert-function () |
78540c42 GM |
232 | "Function that `electric-indent-mode' adds to `post-self-insert-hook'. |
233 | This indents if the hook `electric-indent-functions' returns non-nil, | |
234 | or if a member of `electric-indent-chars' was typed; but not in a string | |
235 | or comment." | |
3b843809 SM |
236 | ;; FIXME: This reindents the current line, but what we really want instead is |
237 | ;; to reindent the whole affected text. That's the current line for simple | |
238 | ;; cases, but not all cases. We do take care of the newline case in an | |
239 | ;; ad-hoc fashion, but there are still missing cases such as the case of | |
240 | ;; electric-pair-mode wrapping a region with a pair of parens. | |
241 | ;; There might be a way to get it working by analyzing buffer-undo-list, but | |
242 | ;; it looks challenging. | |
7100ff98 | 243 | (let (pos) |
6f5e57e7 | 244 | (when (and |
cfc7d5da | 245 | electric-indent-mode |
6f5e57e7 SM |
246 | ;; Don't reindent while inserting spaces at beginning of line. |
247 | (or (not (memq last-command-event '(?\s ?\t))) | |
248 | (save-excursion (skip-chars-backward " \t") (not (bolp)))) | |
249 | (setq pos (electric--after-char-pos)) | |
250 | (save-excursion | |
251 | (goto-char pos) | |
252 | (let ((act (or (run-hook-with-args-until-success | |
253 | 'electric-indent-functions | |
254 | last-command-event) | |
255 | (memq last-command-event electric-indent-chars)))) | |
256 | (not | |
257 | (or (memq act '(nil no-indent)) | |
258 | ;; In a string or comment. | |
259 | (unless (eq act 'do-indent) (nth 8 (syntax-ppss)))))))) | |
7100ff98 SM |
260 | ;; For newline, we want to reindent both lines and basically behave like |
261 | ;; reindent-then-newline-and-indent (whose code we hence copied). | |
3ebdceaf PR |
262 | (let ((at-newline (<= pos (line-beginning-position)))) |
263 | (when at-newline | |
264 | (let ((before (copy-marker (1- pos) t))) | |
265 | (save-excursion | |
266 | (unless (or (memq indent-line-function | |
267 | electric-indent-functions-without-reindent) | |
268 | electric-indent-inhibit) | |
269 | ;; Don't reindent the previous line if the indentation function | |
270 | ;; is not a real one. | |
271 | (goto-char before) | |
272 | (indent-according-to-mode)) | |
273 | ;; We are at EOL before the call to indent-according-to-mode, and | |
274 | ;; after it we usually are as well, but not always. We tried to | |
275 | ;; address it with `save-excursion' but that uses a normal marker | |
276 | ;; whereas we need `move after insertion', so we do the | |
277 | ;; save/restore by hand. | |
a733fc37 | 278 | (goto-char before) |
3ebdceaf PR |
279 | (when (eolp) |
280 | ;; Remove the trailing whitespace after indentation because | |
281 | ;; indentation may (re)introduce the whitespace. | |
282 | (delete-horizontal-space t))))) | |
283 | (unless (and electric-indent-inhibit | |
284 | (not at-newline)) | |
285 | (indent-according-to-mode)))))) | |
3b843809 | 286 | |
3b8d5131 JT |
287 | (put 'electric-indent-post-self-insert-function 'priority 60) |
288 | ||
feca4e2d SM |
289 | (defun electric-indent-just-newline (arg) |
290 | "Insert just a newline, without any auto-indentation." | |
291 | (interactive "*P") | |
292 | (let ((electric-indent-mode nil)) | |
293 | (newline arg 'interactive))) | |
294 | ||
b88eed60 SM |
295 | ;;;###autoload |
296 | (define-key global-map "\C-j" 'electric-newline-and-maybe-indent) | |
494ec1e7 SM |
297 | ;;;###autoload |
298 | (defun electric-newline-and-maybe-indent () | |
299 | "Insert a newline. | |
300 | If `electric-indent-mode' is enabled, that's that, but if it | |
301 | is *disabled* then additionally indent according to major mode. | |
302 | Indentation is done using the value of `indent-line-function'. | |
303 | In programming language modes, this is the same as TAB. | |
304 | In some text modes, where TAB inserts a tab, this command indents to the | |
305 | column specified by the function `current-left-margin'." | |
306 | (interactive "*") | |
307 | (if electric-indent-mode | |
308 | (electric-indent-just-newline nil) | |
309 | (newline-and-indent))) | |
8d4901dc | 310 | |
3b843809 SM |
311 | ;;;###autoload |
312 | (define-minor-mode electric-indent-mode | |
06e21633 CY |
313 | "Toggle on-the-fly reindentation (Electric Indent mode). |
314 | With a prefix argument ARG, enable Electric Indent mode if ARG is | |
315 | positive, and disable it otherwise. If called from Lisp, enable | |
316 | the mode if ARG is omitted or nil. | |
317 | ||
8a51e8e4 GM |
318 | When enabled, this reindents whenever the hook `electric-indent-functions' |
319 | returns non-nil, or if you insert a character from `electric-indent-chars'. | |
320 | ||
321 | This is a global minor mode. To toggle the mode in a single buffer, | |
322 | use `electric-indent-local-mode'." | |
feca4e2d | 323 | :global t :group 'electricity |
da048127 SM |
324 | :initialize 'custom-initialize-delay |
325 | :init-value t | |
24f3d7b9 | 326 | (if (not electric-indent-mode) |
494ec1e7 SM |
327 | (unless (catch 'found |
328 | (dolist (buf (buffer-list)) | |
329 | (with-current-buffer buf | |
330 | (if electric-indent-mode (throw 'found t))))) | |
25158c76 SM |
331 | (remove-hook 'post-self-insert-hook |
332 | #'electric-indent-post-self-insert-function)) | |
24f3d7b9 | 333 | (add-hook 'post-self-insert-hook |
3b8d5131 JT |
334 | #'electric-indent-post-self-insert-function) |
335 | (electric--sort-post-self-insertion-hook))) | |
3b843809 | 336 | |
a35287ea SM |
337 | ;;;###autoload |
338 | (define-minor-mode electric-indent-local-mode | |
339 | "Toggle `electric-indent-mode' only in this buffer." | |
340 | :variable (buffer-local-value 'electric-indent-mode (current-buffer)) | |
341 | (cond | |
342 | ((eq electric-indent-mode (default-value 'electric-indent-mode)) | |
343 | (kill-local-variable 'electric-indent-mode)) | |
344 | ((not (default-value 'electric-indent-mode)) | |
345 | ;; Locally enabled, but globally disabled. | |
346 | (electric-indent-mode 1) ; Setup the hooks. | |
347 | (setq-default electric-indent-mode nil) ; But keep it globally disabled. | |
348 | ))) | |
349 | ||
2abb4e65 | 350 | ;;; Electric newlines after/before/around some chars. |
7100ff98 | 351 | |
3b8d5131 | 352 | (defvar electric-layout-rules nil |
7100ff98 | 353 | "List of rules saying where to automatically insert newlines. |
3b8d5131 JT |
354 | |
355 | Each rule has the form (CHAR . WHERE) where CHAR is the char that | |
356 | was just inserted and WHERE specifies where to insert newlines | |
357 | and can be: nil, `before', `after', `around', `after-stay', or a | |
358 | function of no arguments that returns one of those symbols. | |
359 | ||
360 | The symbols specify where in relation to CHAR the newline | |
361 | character(s) should be inserted. `after-stay' means insert a | |
362 | newline after CHAR but stay in the same place.") | |
7100ff98 SM |
363 | |
364 | (defun electric-layout-post-self-insert-function () | |
365 | (let* ((rule (cdr (assq last-command-event electric-layout-rules))) | |
366 | pos) | |
367 | (when (and rule | |
368 | (setq pos (electric--after-char-pos)) | |
369 | ;; Not in a string or comment. | |
370 | (not (nth 8 (save-excursion (syntax-ppss pos))))) | |
9c3883b4 | 371 | (let ((end (point-marker)) |
3b8d5131 JT |
372 | (sym (if (functionp rule) (funcall rule) rule))) |
373 | (set-marker-insertion-type end (not (eq sym 'after-stay))) | |
7100ff98 | 374 | (goto-char pos) |
3b8d5131 | 375 | (pcase sym |
7100ff98 SM |
376 | ;; FIXME: we used `newline' down here which called |
377 | ;; self-insert-command and ran post-self-insert-hook recursively. | |
378 | ;; It happened to make electric-indent-mode work automatically with | |
379 | ;; electric-layout-mode (at the cost of re-indenting lines | |
380 | ;; multiple times), but I'm not sure it's what we want. | |
3b8d5131 JT |
381 | ;; |
382 | ;; FIXME: check eolp before inserting \n? | |
f58e0fd5 | 383 | (`before (goto-char (1- pos)) (skip-chars-backward " \t") |
3b8d5131 JT |
384 | (unless (bolp) (insert "\n"))) |
385 | (`after (insert "\n")) | |
386 | (`after-stay (save-excursion | |
387 | (let ((electric-layout-rules nil)) | |
388 | (newline 1 t)))) | |
f58e0fd5 | 389 | (`around (save-excursion |
3b8d5131 JT |
390 | (goto-char (1- pos)) (skip-chars-backward " \t") |
391 | (unless (bolp) (insert "\n"))) | |
392 | (insert "\n"))) ; FIXME: check eolp before inserting \n? | |
7100ff98 SM |
393 | (goto-char end))))) |
394 | ||
3b8d5131 JT |
395 | (put 'electric-layout-post-self-insert-function 'priority 40) |
396 | ||
7100ff98 SM |
397 | ;;;###autoload |
398 | (define-minor-mode electric-layout-mode | |
e1ac4066 GM |
399 | "Automatically insert newlines around some chars. |
400 | With a prefix argument ARG, enable Electric Layout mode if ARG is | |
401 | positive, and disable it otherwise. If called from Lisp, enable | |
a075a2c5 GM |
402 | the mode if ARG is omitted or nil. |
403 | The variable `electric-layout-rules' says when and how to insert newlines." | |
feca4e2d | 404 | :global t :group 'electricity |
3b8d5131 JT |
405 | (cond (electric-layout-mode |
406 | (add-hook 'post-self-insert-hook | |
407 | #'electric-layout-post-self-insert-function) | |
408 | (electric--sort-post-self-insertion-hook)) | |
409 | (t | |
410 | (remove-hook 'post-self-insert-hook | |
411 | #'electric-layout-post-self-insert-function)))) | |
7100ff98 | 412 | |
c0274f38 ER |
413 | (provide 'electric) |
414 | ||
c8472948 | 415 | ;;; electric.el ends here |