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e8af40ee | 1 | ;;; jit-lock.el --- just-in-time fontification |
7840ced1 | 2 | |
0d30b337 | 3 | ;; Copyright (C) 1998, 2000, 2001, 2002, 2003, 2004, |
aaef169d | 4 | ;; 2005, 2006 Free Software Foundation, Inc. |
7840ced1 GM |
5 | |
6 | ;; Author: Gerd Moellmann <gerd@gnu.org> | |
7 | ;; Keywords: faces files | |
7840ced1 GM |
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. | |
7840ced1 GM |
25 | |
26 | ;;; Commentary: | |
27 | ||
28 | ;; Just-in-time fontification, triggered by C redisplay code. | |
29 | ||
30 | ;;; Code: | |
31 | ||
32 | ||
7840ced1 | 33 | (eval-when-compile |
60bffb78 GM |
34 | (defmacro with-buffer-unmodified (&rest body) |
35 | "Eval BODY, preserving the current buffer's modified state." | |
7b4d9d3b | 36 | (declare (debug t)) |
60bffb78 GM |
37 | (let ((modified (make-symbol "modified"))) |
38 | `(let ((,modified (buffer-modified-p))) | |
be390cb3 SM |
39 | (unwind-protect |
40 | (progn ,@body) | |
41 | (unless ,modified | |
42 | (restore-buffer-modified-p nil)))))) | |
f1180544 | 43 | |
bcacade9 | 44 | (defmacro with-buffer-prepared-for-jit-lock (&rest body) |
7840ced1 GM |
45 | "Execute BODY in current buffer, overriding several variables. |
46 | Preserves the `buffer-modified-p' state of the current buffer." | |
7b4d9d3b | 47 | (declare (debug t)) |
9f1a8fb4 GM |
48 | `(with-buffer-unmodified |
49 | (let ((buffer-undo-list t) | |
50 | (inhibit-read-only t) | |
51 | (inhibit-point-motion-hooks t) | |
bcacade9 | 52 | (inhibit-modification-hooks t) |
9f1a8fb4 GM |
53 | deactivate-mark |
54 | buffer-file-name | |
55 | buffer-file-truename) | |
56 | ,@body)))) | |
7840ced1 | 57 | |
f1180544 | 58 | |
7840ced1 GM |
59 | \f |
60 | ;;; Customization. | |
61 | ||
623a1226 SM |
62 | (defgroup jit-lock nil |
63 | "Font Lock support mode to fontify just-in-time." | |
623a1226 SM |
64 | :version "21.1" |
65 | :group 'font-lock) | |
66 | ||
7840ced1 | 67 | (defcustom jit-lock-chunk-size 500 |
45cb4c96 EZ |
68 | "*Jit-lock fontifies chunks of at most this many characters at a time. |
69 | ||
70 | This variable controls both display-time and stealth fontification." | |
7840ced1 GM |
71 | :type 'integer |
72 | :group 'jit-lock) | |
73 | ||
74 | ||
4739237d | 75 | (defcustom jit-lock-stealth-time 16 |
7840ced1 GM |
76 | "*Time in seconds to wait before beginning stealth fontification. |
77 | Stealth fontification occurs if there is no input within this time. | |
f86292a9 | 78 | If nil, stealth fontification is never performed. |
7840ced1 GM |
79 | |
80 | The value of this variable is used when JIT Lock mode is turned on." | |
81 | :type '(choice (const :tag "never" nil) | |
82 | (number :tag "seconds")) | |
83 | :group 'jit-lock) | |
84 | ||
85 | ||
4739237d | 86 | (defcustom jit-lock-stealth-nice 0.5 |
7840ced1 GM |
87 | "*Time in seconds to pause between chunks of stealth fontification. |
88 | Each iteration of stealth fontification is separated by this amount of time, | |
89 | thus reducing the demand that stealth fontification makes on the system. | |
90 | If nil, means stealth fontification is never paused. | |
91 | To reduce machine load during stealth fontification, at the cost of stealth | |
92 | taking longer to fontify, you could increase the value of this variable. | |
93 | See also `jit-lock-stealth-load'." | |
94 | :type '(choice (const :tag "never" nil) | |
f1180544 | 95 | (number :tag "seconds")) |
7840ced1 | 96 | :group 'jit-lock) |
f1180544 | 97 | |
7840ced1 GM |
98 | |
99 | (defcustom jit-lock-stealth-load | |
100 | (if (condition-case nil (load-average) (error)) 200) | |
101 | "*Load in percentage above which stealth fontification is suspended. | |
102 | Stealth fontification pauses when the system short-term load average (as | |
103 | returned by the function `load-average' if supported) goes above this level, | |
104 | thus reducing the demand that stealth fontification makes on the system. | |
105 | If nil, means stealth fontification is never suspended. | |
106 | To reduce machine load during stealth fontification, at the cost of stealth | |
107 | taking longer to fontify, you could reduce the value of this variable. | |
108 | See also `jit-lock-stealth-nice'." | |
109 | :type (if (condition-case nil (load-average) (error)) | |
110 | '(choice (const :tag "never" nil) | |
111 | (integer :tag "load")) | |
112 | '(const :format "%t: unsupported\n" nil)) | |
113 | :group 'jit-lock) | |
114 | ||
115 | ||
116 | (defcustom jit-lock-stealth-verbose nil | |
117 | "*If non-nil, means stealth fontification should show status messages." | |
118 | :type 'boolean | |
119 | :group 'jit-lock) | |
120 | ||
121 | ||
f415f2d7 SM |
122 | (defvaralias 'jit-lock-defer-contextually 'jit-lock-contextually) |
123 | (defcustom jit-lock-contextually 'syntax-driven | |
124 | "*If non-nil, means fontification should be syntactically true. | |
125 | If nil, means fontification occurs only on those lines modified. This | |
7840ced1 GM |
126 | means where modification on a line causes syntactic change on subsequent lines, |
127 | those subsequent lines are not refontified to reflect their new context. | |
f415f2d7 | 128 | If t, means fontification occurs on those lines modified and all |
7840ced1 | 129 | subsequent lines. This means those subsequent lines are refontified to reflect |
7b4d9d3b | 130 | their new syntactic context, after `jit-lock-context-time' seconds. |
f415f2d7 | 131 | If any other value, e.g., `syntax-driven', means syntactically true |
7840ced1 GM |
132 | fontification occurs only if syntactic fontification is performed using the |
133 | buffer mode's syntax table, i.e., only if `font-lock-keywords-only' is nil. | |
134 | ||
135 | The value of this variable is used when JIT Lock mode is turned on." | |
136 | :type '(choice (const :tag "never" nil) | |
137 | (const :tag "always" t) | |
138 | (other :tag "syntax-driven" syntax-driven)) | |
139 | :group 'jit-lock) | |
140 | ||
7b4d9d3b SM |
141 | (defcustom jit-lock-context-time 0.5 |
142 | "Idle time after which text is contextually refontified, if applicable." | |
f5307782 JB |
143 | :type '(number :tag "seconds") |
144 | :group 'jit-lock) | |
145 | ||
8e069ce2 | 146 | (defcustom jit-lock-defer-time nil ;; 0.25 |
b743187d SM |
147 | "Idle time after which deferred fontification should take place. |
148 | If nil, fontification is not deferred." | |
149 | :group 'jit-lock | |
150 | :type '(choice (const :tag "never" nil) | |
151 | (number :tag "seconds"))) | |
7840ced1 GM |
152 | \f |
153 | ;;; Variables that are not customizable. | |
154 | ||
155 | (defvar jit-lock-mode nil | |
156 | "Non-nil means Just-in-time Lock mode is active.") | |
157 | (make-variable-buffer-local 'jit-lock-mode) | |
158 | ||
be390cb3 SM |
159 | (defvar jit-lock-functions nil |
160 | "Functions to do the actual fontification. | |
161 | They are called with two arguments: the START and END of the region to fontify.") | |
a62e3c6f | 162 | (make-variable-buffer-local 'jit-lock-functions) |
7840ced1 | 163 | |
623a1226 | 164 | (defvar jit-lock-context-unfontify-pos nil |
a62e3c6f | 165 | "Consider text after this position as contextually unfontified. |
bcacade9 | 166 | If nil, contextual fontification is disabled.") |
623a1226 | 167 | (make-variable-buffer-local 'jit-lock-context-unfontify-pos) |
7840ced1 GM |
168 | |
169 | ||
170 | (defvar jit-lock-stealth-timer nil | |
171 | "Timer for stealth fontification in Just-in-time Lock mode.") | |
7b4d9d3b SM |
172 | (defvar jit-lock-context-timer nil |
173 | "Timer for context fontification in Just-in-time Lock mode.") | |
b743187d SM |
174 | (defvar jit-lock-defer-timer nil |
175 | "Timer for deferred fontification in Just-in-time Lock mode.") | |
176 | ||
623a1226 | 177 | (defvar jit-lock-defer-buffers nil |
b743187d | 178 | "List of buffers with pending deferred fontification.") |
7840ced1 GM |
179 | \f |
180 | ;;; JIT lock mode | |
181 | ||
7840ced1 GM |
182 | (defun jit-lock-mode (arg) |
183 | "Toggle Just-in-time Lock mode. | |
bcacade9 | 184 | Turn Just-in-time Lock mode on if and only if ARG is non-nil. |
7840ced1 GM |
185 | Enable it automatically by customizing group `font-lock'. |
186 | ||
187 | When Just-in-time Lock mode is enabled, fontification is different in the | |
188 | following ways: | |
189 | ||
190 | - Demand-driven buffer fontification triggered by Emacs C code. | |
191 | This means initial fontification of the whole buffer does not occur. | |
192 | Instead, fontification occurs when necessary, such as when scrolling | |
193 | through the buffer would otherwise reveal unfontified areas. This is | |
194 | useful if buffer fontification is too slow for large buffers. | |
195 | ||
196 | - Stealthy buffer fontification if `jit-lock-stealth-time' is non-nil. | |
197 | This means remaining unfontified areas of buffers are fontified if Emacs has | |
198 | been idle for `jit-lock-stealth-time' seconds, while Emacs remains idle. | |
199 | This is useful if any buffer has any deferred fontification. | |
200 | ||
f415f2d7 | 201 | - Deferred context fontification if `jit-lock-contextually' is |
7840ced1 | 202 | non-nil. This means fontification updates the buffer corresponding to |
7b4d9d3b | 203 | true syntactic context, after `jit-lock-context-time' seconds of Emacs |
7840ced1 GM |
204 | idle time, while Emacs remains idle. Otherwise, fontification occurs |
205 | on modified lines only, and subsequent lines can remain fontified | |
206 | corresponding to previous syntactic contexts. This is useful where | |
207 | strings or comments span lines. | |
208 | ||
209 | Stealth fontification only occurs while the system remains unloaded. | |
210 | If the system load rises above `jit-lock-stealth-load' percent, stealth | |
211 | fontification is suspended. Stealth fontification intensity is controlled via | |
02b420eb | 212 | the variable `jit-lock-stealth-nice'." |
bcacade9 SM |
213 | (setq jit-lock-mode arg) |
214 | (cond (;; Turn Just-in-time Lock mode on. | |
215 | jit-lock-mode | |
216 | ||
b743187d | 217 | ;; Mark the buffer for refontification. |
a62e3c6f | 218 | (jit-lock-refontify) |
02b420eb | 219 | |
7840ced1 | 220 | ;; Install an idle timer for stealth fontification. |
c94d5f40 | 221 | (when (and jit-lock-stealth-time (null jit-lock-stealth-timer)) |
02b420eb | 222 | (setq jit-lock-stealth-timer |
b743187d | 223 | (run-with-idle-timer jit-lock-stealth-time t |
7840ced1 GM |
224 | 'jit-lock-stealth-fontify))) |
225 | ||
b743187d SM |
226 | ;; Init deferred fontification timer. |
227 | (when (and jit-lock-defer-time (null jit-lock-defer-timer)) | |
228 | (setq jit-lock-defer-timer | |
229 | (run-with-idle-timer jit-lock-defer-time t | |
230 | 'jit-lock-deferred-fontify))) | |
231 | ||
623a1226 | 232 | ;; Initialize contextual fontification if requested. |
f415f2d7 | 233 | (when (eq jit-lock-contextually t) |
7b4d9d3b SM |
234 | (unless jit-lock-context-timer |
235 | (setq jit-lock-context-timer | |
236 | (run-with-idle-timer jit-lock-context-time t | |
237 | 'jit-lock-context-fontify))) | |
623a1226 SM |
238 | (setq jit-lock-context-unfontify-pos |
239 | (or jit-lock-context-unfontify-pos (point-max)))) | |
bcacade9 | 240 | |
a62e3c6f | 241 | ;; Setup our hooks. |
bcacade9 | 242 | (add-hook 'after-change-functions 'jit-lock-after-change nil t) |
7840ced1 GM |
243 | (add-hook 'fontification-functions 'jit-lock-function)) |
244 | ||
245 | ;; Turn Just-in-time Lock mode off. | |
246 | (t | |
b743187d | 247 | ;; Cancel our idle timers. |
7b4d9d3b SM |
248 | (when (and (or jit-lock-stealth-timer jit-lock-defer-timer |
249 | jit-lock-context-timer) | |
b743187d SM |
250 | ;; Only if there's no other buffer using them. |
251 | (not (catch 'found | |
252 | (dolist (buf (buffer-list)) | |
253 | (with-current-buffer buf | |
254 | (when jit-lock-mode (throw 'found t))))))) | |
255 | (when jit-lock-stealth-timer | |
256 | (cancel-timer jit-lock-stealth-timer) | |
257 | (setq jit-lock-stealth-timer nil)) | |
7b4d9d3b SM |
258 | (when jit-lock-context-timer |
259 | (cancel-timer jit-lock-context-timer) | |
260 | (setq jit-lock-context-timer nil)) | |
b743187d SM |
261 | (when jit-lock-defer-timer |
262 | (cancel-timer jit-lock-defer-timer) | |
263 | (setq jit-lock-defer-timer nil))) | |
7840ced1 | 264 | |
a62e3c6f | 265 | ;; Remove hooks. |
02b420eb | 266 | (remove-hook 'after-change-functions 'jit-lock-after-change t) |
7840ced1 GM |
267 | (remove-hook 'fontification-functions 'jit-lock-function)))) |
268 | ||
c94d5f40 | 269 | (defun jit-lock-register (fun &optional contextual) |
8a677d4f SM |
270 | "Register FUN as a fontification function to be called in this buffer. |
271 | FUN will be called with two arguments START and END indicating the region | |
c94d5f40 SM |
272 | that needs to be (re)fontified. |
273 | If non-nil, CONTEXTUAL means that a contextual fontification would be useful." | |
f8bacc70 | 274 | (add-hook 'jit-lock-functions fun nil t) |
f415f2d7 SM |
275 | (when (and contextual jit-lock-contextually) |
276 | (set (make-local-variable 'jit-lock-contextually) t)) | |
f8bacc70 SM |
277 | (jit-lock-mode t)) |
278 | ||
279 | (defun jit-lock-unregister (fun) | |
8a677d4f | 280 | "Unregister FUN as a fontification function. |
f8bacc70 SM |
281 | Only applies to the current buffer." |
282 | (remove-hook 'jit-lock-functions fun t) | |
a62e3c6f | 283 | (unless jit-lock-functions (jit-lock-mode nil))) |
7840ced1 | 284 | |
02b420eb SM |
285 | ;; This function is used to prevent font-lock-fontify-buffer from |
286 | ;; fontifying eagerly the whole buffer. This is important for | |
287 | ;; things like CWarn mode which adds/removes a few keywords and | |
288 | ;; does a refontify (which takes ages on large files). | |
a62e3c6f SM |
289 | (defun jit-lock-refontify (&optional beg end) |
290 | "Force refontification of the region BEG..END (default whole buffer)." | |
bcacade9 | 291 | (with-buffer-prepared-for-jit-lock |
5a5987eb SM |
292 | (save-restriction |
293 | (widen) | |
b743187d SM |
294 | (put-text-property (or beg (point-min)) (or end (point-max)) |
295 | 'fontified nil)))) | |
7840ced1 GM |
296 | \f |
297 | ;;; On demand fontification. | |
298 | ||
299 | (defun jit-lock-function (start) | |
300 | "Fontify current buffer starting at position START. | |
301 | This function is added to `fontification-functions' when `jit-lock-mode' | |
302 | is active." | |
74614ac6 | 303 | (when (and jit-lock-mode (not memory-full)) |
b743187d SM |
304 | (if (null jit-lock-defer-time) |
305 | ;; No deferral. | |
306 | (jit-lock-fontify-now start (+ start jit-lock-chunk-size)) | |
307 | ;; Record the buffer for later fontification. | |
623a1226 SM |
308 | (unless (memq (current-buffer) jit-lock-defer-buffers) |
309 | (push (current-buffer) jit-lock-defer-buffers)) | |
b743187d SM |
310 | ;; Mark the area as defer-fontified so that the redisplay engine |
311 | ;; is happy and so that the idle timer can find the places to fontify. | |
312 | (with-buffer-prepared-for-jit-lock | |
313 | (put-text-property start | |
314 | (next-single-property-change | |
315 | start 'fontified nil | |
316 | (min (point-max) (+ start jit-lock-chunk-size))) | |
317 | 'fontified 'defer))))) | |
a62e3c6f SM |
318 | |
319 | (defun jit-lock-fontify-now (&optional start end) | |
320 | "Fontify current buffer from START to END. | |
321 | Defaults to the whole buffer. END can be out of bounds." | |
bcacade9 | 322 | (with-buffer-prepared-for-jit-lock |
60bffb78 | 323 | (save-excursion |
c9cf2e67 SM |
324 | (unless start (setq start (point-min))) |
325 | (setq end (if end (min end (point-max)) (point-max))) | |
326 | ;; This did bind `font-lock-beginning-of-syntax-function' to | |
327 | ;; nil at some point, for an unknown reason. Don't do this; it | |
328 | ;; can make highlighting slow due to expensive calls to | |
329 | ;; `parse-partial-sexp' in function | |
330 | ;; `font-lock-fontify-syntactically-region'. Example: paging | |
331 | ;; from the end of a buffer to its start, can do repeated | |
332 | ;; `parse-partial-sexp' starting from `point-min', which can | |
333 | ;; take a long time in a large buffer. | |
334 | (let (next) | |
335 | (save-match-data | |
336 | ;; Fontify chunks beginning at START. The end of a | |
337 | ;; chunk is either `end', or the start of a region | |
338 | ;; before `end' that has already been fontified. | |
339 | (while start | |
340 | ;; Determine the end of this chunk. | |
341 | (setq next (or (text-property-any start end 'fontified t) | |
342 | end)) | |
343 | ||
344 | ;; Decide which range of text should be fontified. | |
345 | ;; The problem is that START and NEXT may be in the | |
346 | ;; middle of something matched by a font-lock regexp. | |
347 | ;; Until someone has a better idea, let's start | |
348 | ;; at the start of the line containing START and | |
349 | ;; stop at the start of the line following NEXT. | |
350 | (goto-char next) (setq next (line-beginning-position 2)) | |
351 | (goto-char start) (setq start (line-beginning-position)) | |
f1180544 | 352 | |
c4ac63d0 SM |
353 | ;; Make sure the contextual refontification doesn't re-refontify |
354 | ;; what's already been refontified. | |
c4ac63d0 SM |
355 | (when (and jit-lock-context-unfontify-pos |
356 | (< jit-lock-context-unfontify-pos next) | |
7aaf6f17 SM |
357 | (>= jit-lock-context-unfontify-pos start) |
358 | ;; Don't move boundary forward if we have to | |
359 | ;; refontify previous text. Otherwise, we risk moving | |
360 | ;; it past the end of the multiline property and thus | |
361 | ;; forget about this multiline region altogether. | |
362 | (not (get-text-property start 'jit-lock-defer-multiline))) | |
c4ac63d0 SM |
363 | (setq jit-lock-context-unfontify-pos next)) |
364 | ||
c9cf2e67 SM |
365 | ;; Fontify the chunk, and mark it as fontified. |
366 | ;; We mark it first, to make sure that we don't indefinitely | |
367 | ;; re-execute this fontification if an error occurs. | |
368 | (put-text-property start next 'fontified t) | |
f415f2d7 SM |
369 | (condition-case err |
370 | (run-hook-with-args 'jit-lock-functions start next) | |
371 | ;; If the user quits (which shouldn't happen in normal on-the-fly | |
372 | ;; jit-locking), make sure the fontification will be performed | |
373 | ;; before displaying the block again. | |
374 | (quit (put-text-property start next 'fontified nil) | |
375 | (funcall 'signal (car err) (cdr err)))) | |
c9cf2e67 SM |
376 | |
377 | ;; Find the start of the next chunk, if any. | |
378 | (setq start (text-property-any next end 'fontified nil)))))))) | |
7840ced1 | 379 | |
7840ced1 GM |
380 | \f |
381 | ;;; Stealth fontification. | |
382 | ||
383 | (defsubst jit-lock-stealth-chunk-start (around) | |
384 | "Return the start of the next chunk to fontify around position AROUND.. | |
385 | Value is nil if there is nothing more to fontify." | |
8c887c51 GM |
386 | (if (zerop (buffer-size)) |
387 | nil | |
388 | (save-restriction | |
389 | (widen) | |
b743187d | 390 | (let* ((next (text-property-not-all around (point-max) 'fontified t)) |
8c887c51 GM |
391 | (prev (previous-single-property-change around 'fontified)) |
392 | (prop (get-text-property (max (point-min) (1- around)) | |
393 | 'fontified)) | |
394 | (start (cond | |
395 | ((null prev) | |
396 | ;; There is no property change between AROUND | |
397 | ;; and the start of the buffer. If PROP is | |
398 | ;; non-nil, everything in front of AROUND is | |
399 | ;; fontified, otherwise nothing is fontified. | |
b743187d | 400 | (if (eq prop t) |
8c887c51 GM |
401 | nil |
402 | (max (point-min) | |
403 | (- around (/ jit-lock-chunk-size 2))))) | |
b743187d | 404 | ((eq prop t) |
8c887c51 | 405 | ;; PREV is the start of a region of fontified |
bcacade9 | 406 | ;; text containing AROUND. Start fontifying a |
8c887c51 GM |
407 | ;; chunk size before the end of the unfontified |
408 | ;; region in front of that. | |
409 | (max (or (previous-single-property-change prev 'fontified) | |
410 | (point-min)) | |
411 | (- prev jit-lock-chunk-size))) | |
412 | (t | |
413 | ;; PREV is the start of a region of unfontified | |
414 | ;; text containing AROUND. Start at PREV or | |
415 | ;; chunk size in front of AROUND, whichever is | |
416 | ;; nearer. | |
417 | (max prev (- around jit-lock-chunk-size))))) | |
418 | (result (cond ((null start) next) | |
419 | ((null next) start) | |
420 | ((< (- around start) (- next around)) start) | |
421 | (t next)))) | |
422 | result)))) | |
f1180544 | 423 | |
7840ced1 GM |
424 | |
425 | (defun jit-lock-stealth-fontify () | |
426 | "Fontify buffers stealthily. | |
427 | This functions is called after Emacs has been idle for | |
428 | `jit-lock-stealth-time' seconds." | |
b743187d | 429 | ;; I used to check `inhibit-read-only' here, but I can't remember why. -stef |
7840ced1 | 430 | (unless (or executing-kbd-macro |
74614ac6 | 431 | memory-full |
7840ced1 GM |
432 | (window-minibuffer-p (selected-window))) |
433 | (let ((buffers (buffer-list)) | |
2e0a74c6 | 434 | (outer-buffer (current-buffer)) |
7840ced1 GM |
435 | minibuffer-auto-raise |
436 | message-log-max) | |
f415f2d7 SM |
437 | (with-local-quit |
438 | (while (and buffers (not (input-pending-p))) | |
439 | (with-current-buffer (pop buffers) | |
7840ced1 GM |
440 | (when jit-lock-mode |
441 | ;; This is funny. Calling sit-for with 3rd arg non-nil | |
442 | ;; so that it doesn't redisplay, internally calls | |
443 | ;; wait_reading_process_input also with a parameter | |
444 | ;; saying "don't redisplay." Since this function here | |
445 | ;; is called periodically, this effectively leads to | |
446 | ;; process output not being redisplayed at all because | |
447 | ;; redisplay_internal is never called. (That didn't | |
448 | ;; work in the old redisplay either.) So, we learn that | |
449 | ;; we mustn't call sit-for that way here. But then, we | |
450 | ;; have to be cautious not to call sit-for in a widened | |
451 | ;; buffer, since this could display hidden parts of that | |
452 | ;; buffer. This explains the seemingly weird use of | |
453 | ;; save-restriction/widen here. | |
454 | ||
455 | (with-temp-message (if jit-lock-stealth-verbose | |
456 | (concat "JIT stealth lock " | |
457 | (buffer-name))) | |
8c887c51 | 458 | |
9f1a8fb4 GM |
459 | ;; In the following code, the `sit-for' calls cause a |
460 | ;; redisplay, so it's required that the | |
461 | ;; buffer-modified flag of a buffer that is displayed | |
462 | ;; has the right value---otherwise the mode line of | |
463 | ;; an unmodified buffer would show a `*'. | |
464 | (let (start | |
465 | (nice (or jit-lock-stealth-nice 0)) | |
b743187d | 466 | (point (point-min))) |
9f1a8fb4 GM |
467 | (while (and (setq start |
468 | (jit-lock-stealth-chunk-start point)) | |
2e0a74c6 RS |
469 | ;; In case sit-for runs any timers, |
470 | ;; give them the expected current buffer. | |
471 | (with-current-buffer outer-buffer | |
472 | (sit-for nice))) | |
f1180544 | 473 | |
b743187d SM |
474 | ;; fontify a block. |
475 | (jit-lock-fontify-now start (+ start jit-lock-chunk-size)) | |
476 | ;; If stealth jit-locking is done backwards, this leads to | |
477 | ;; excessive O(n^2) refontification. -stef | |
623a1226 SM |
478 | ;; (when (>= jit-lock-context-unfontify-pos start) |
479 | ;; (setq jit-lock-context-unfontify-pos end)) | |
f1180544 | 480 | |
9f1a8fb4 GM |
481 | ;; Wait a little if load is too high. |
482 | (when (and jit-lock-stealth-load | |
483 | (> (car (load-average)) jit-lock-stealth-load)) | |
2e0a74c6 RS |
484 | ;; In case sit-for runs any timers, |
485 | ;; give them the expected current buffer. | |
486 | (with-current-buffer outer-buffer | |
487 | (sit-for (or jit-lock-stealth-time 30)))))))))))))) | |
7840ced1 GM |
488 | |
489 | ||
490 | \f | |
491 | ;;; Deferred fontification. | |
492 | ||
b743187d SM |
493 | (defun jit-lock-deferred-fontify () |
494 | "Fontify what was deferred." | |
74614ac6 | 495 | (when (and jit-lock-defer-buffers (not memory-full)) |
b743187d | 496 | ;; Mark the deferred regions back to `fontified = nil' |
623a1226 | 497 | (dolist (buffer jit-lock-defer-buffers) |
b743187d SM |
498 | (when (buffer-live-p buffer) |
499 | (with-current-buffer buffer | |
500 | ;; (message "Jit-Defer %s" (buffer-name)) | |
501 | (with-buffer-prepared-for-jit-lock | |
502 | (let ((pos (point-min))) | |
503 | (while | |
504 | (progn | |
505 | (when (eq (get-text-property pos 'fontified) 'defer) | |
506 | (put-text-property | |
507 | pos (setq pos (next-single-property-change | |
508 | pos 'fontified nil (point-max))) | |
509 | 'fontified nil)) | |
510 | (setq pos (next-single-property-change pos 'fontified))))))))) | |
623a1226 | 511 | (setq jit-lock-defer-buffers nil) |
b743187d SM |
512 | ;; Force fontification of the visible parts. |
513 | (let ((jit-lock-defer-time nil)) | |
514 | ;; (message "Jit-Defer Now") | |
515 | (sit-for 0) | |
516 | ;; (message "Jit-Defer Done") | |
517 | ))) | |
f1180544 | 518 | |
b743187d | 519 | |
7b4d9d3b SM |
520 | (defun jit-lock-context-fontify () |
521 | "Refresh fontification to take new context into account." | |
74614ac6 RS |
522 | (unless memory-full |
523 | (dolist (buffer (buffer-list)) | |
524 | (with-current-buffer buffer | |
525 | (when jit-lock-context-unfontify-pos | |
526 | ;; (message "Jit-Context %s" (buffer-name)) | |
527 | (save-restriction | |
528 | (widen) | |
529 | (when (and (>= jit-lock-context-unfontify-pos (point-min)) | |
530 | (< jit-lock-context-unfontify-pos (point-max))) | |
531 | ;; If we're in text that matches a complex multi-line | |
532 | ;; font-lock pattern, make sure the whole text will be | |
533 | ;; redisplayed eventually. | |
534 | ;; Despite its name, we treat jit-lock-defer-multiline here | |
535 | ;; rather than in jit-lock-defer since it has to do with multiple | |
536 | ;; lines, i.e. with context. | |
537 | (when (get-text-property jit-lock-context-unfontify-pos | |
538 | 'jit-lock-defer-multiline) | |
539 | (setq jit-lock-context-unfontify-pos | |
540 | (or (previous-single-property-change | |
541 | jit-lock-context-unfontify-pos | |
542 | 'jit-lock-defer-multiline) | |
543 | (point-min)))) | |
544 | (with-buffer-prepared-for-jit-lock | |
545 | ;; Force contextual refontification. | |
546 | (remove-text-properties | |
547 | jit-lock-context-unfontify-pos (point-max) | |
548 | '(fontified nil jit-lock-defer-multiline nil))) | |
549 | (setq jit-lock-context-unfontify-pos (point-max))))))))) | |
7b4d9d3b | 550 | |
7840ced1 GM |
551 | (defun jit-lock-after-change (start end old-len) |
552 | "Mark the rest of the buffer as not fontified after a change. | |
553 | Installed on `after-change-functions'. | |
554 | START and END are the start and end of the changed text. OLD-LEN | |
555 | is the pre-change length. | |
556 | This function ensures that lines following the change will be refontified | |
557 | in case the syntax of those lines has changed. Refontification | |
558 | will take place when text is fontified stealthily." | |
74614ac6 | 559 | (when (and jit-lock-mode (not memory-full)) |
ef008321 AM |
560 | (let ((region (font-lock-extend-region start end old-len))) |
561 | (save-excursion | |
562 | (with-buffer-prepared-for-jit-lock | |
563 | ;; It's important that the `fontified' property be set from the | |
564 | ;; beginning of the line, else font-lock will properly change the | |
565 | ;; text's face, but the display will have been done already and will | |
566 | ;; be inconsistent with the buffer's content. | |
567 | ;; | |
568 | ;; FIXME!!! (Alan Mackenzie, 2006-03-14): If start isn't at a BOL, | |
569 | ;; expanding the region to BOL might mis-fontify, should the BOL not | |
570 | ;; be at a "safe" position. | |
571 | (setq start (if region | |
572 | (car region) | |
573 | (goto-char start) | |
4ffc92c2 | 574 | (line-beginning-position))) |
ef008321 AM |
575 | |
576 | ;; If we're in text that matches a multi-line font-lock pattern, | |
577 | ;; make sure the whole text will be redisplayed. | |
578 | ;; I'm not sure this is ever necessary and/or sufficient. -stef | |
579 | (when (get-text-property start 'font-lock-multiline) | |
580 | (setq start (or (previous-single-property-change | |
581 | start 'font-lock-multiline) | |
582 | (point-min)))) | |
583 | ||
584 | (if region (setq end (cdr region))) | |
585 | ;; Make sure we change at least one char (in case of deletions). | |
586 | (setq end (min (max end (1+ start)) (point-max))) | |
587 | ;; Request refontification. | |
588 | (put-text-property start end 'fontified nil)) | |
589 | ;; Mark the change for deferred contextual refontification. | |
590 | (when jit-lock-context-unfontify-pos | |
591 | (setq jit-lock-context-unfontify-pos | |
592 | ;; Here we use `start' because nothing guarantees that the | |
593 | ;; text between start and end will be otherwise refontified: | |
594 | ;; usually it will be refontified by virtue of being | |
595 | ;; displayed, but if it's outside of any displayed area in the | |
596 | ;; buffer, only jit-lock-context-* will re-fontify it. | |
597 | (min jit-lock-context-unfontify-pos start))))))) | |
f1180544 | 598 | |
7840ced1 GM |
599 | (provide 'jit-lock) |
600 | ||
c4ac63d0 | 601 | ;; arch-tag: 56b5de6e-f581-453b-bb97-49c39372ff9e |
e8af40ee | 602 | ;;; jit-lock.el ends here |