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e8af40ee | 1 | ;;; jit-lock.el --- just-in-time fontification |
7840ced1 | 2 | |
623a1226 | 3 | ;; Copyright (C) 1998, 2000, 2001, 2004 Free Software Foundation, Inc. |
7840ced1 GM |
4 | |
5 | ;; Author: Gerd Moellmann <gerd@gnu.org> | |
6 | ;; Keywords: faces files | |
7840ced1 GM |
7 | |
8 | ;; This file is part of GNU Emacs. | |
9 | ||
10 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
11 | ;; it under the terms of the GNU General Public License as published by | |
12 | ;; the Free Software Foundation; either version 2, or (at your option) | |
13 | ;; any later version. | |
14 | ||
15 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
16 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | ;; GNU General Public License for more details. | |
19 | ||
20 | ;; You should have received a copy of the GNU General Public License | |
21 | ;; along with GNU Emacs; see the file COPYING. If not, write to the | |
22 | ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
23 | ;; Boston, MA 02111-1307, USA. | |
24 | ||
25 | ;;; Commentary: | |
26 | ||
27 | ;; Just-in-time fontification, triggered by C redisplay code. | |
28 | ||
29 | ;;; Code: | |
30 | ||
31 | ||
7840ced1 | 32 | (eval-when-compile |
60bffb78 GM |
33 | (defmacro with-buffer-unmodified (&rest body) |
34 | "Eval BODY, preserving the current buffer's modified state." | |
7b4d9d3b | 35 | (declare (debug t)) |
60bffb78 GM |
36 | (let ((modified (make-symbol "modified"))) |
37 | `(let ((,modified (buffer-modified-p))) | |
be390cb3 SM |
38 | (unwind-protect |
39 | (progn ,@body) | |
40 | (unless ,modified | |
41 | (restore-buffer-modified-p nil)))))) | |
f1180544 | 42 | |
bcacade9 | 43 | (defmacro with-buffer-prepared-for-jit-lock (&rest body) |
7840ced1 GM |
44 | "Execute BODY in current buffer, overriding several variables. |
45 | Preserves the `buffer-modified-p' state of the current buffer." | |
7b4d9d3b | 46 | (declare (debug t)) |
9f1a8fb4 GM |
47 | `(with-buffer-unmodified |
48 | (let ((buffer-undo-list t) | |
49 | (inhibit-read-only t) | |
50 | (inhibit-point-motion-hooks t) | |
bcacade9 | 51 | (inhibit-modification-hooks t) |
9f1a8fb4 GM |
52 | deactivate-mark |
53 | buffer-file-name | |
54 | buffer-file-truename) | |
55 | ,@body)))) | |
7840ced1 | 56 | |
f1180544 | 57 | |
7840ced1 GM |
58 | \f |
59 | ;;; Customization. | |
60 | ||
623a1226 SM |
61 | (defgroup jit-lock nil |
62 | "Font Lock support mode to fontify just-in-time." | |
63 | :link '(custom-manual "(emacs)Support Modes") | |
64 | :version "21.1" | |
65 | :group 'font-lock) | |
66 | ||
7840ced1 | 67 | (defcustom jit-lock-chunk-size 500 |
bcacade9 | 68 | "*Jit-lock chunks of this many characters, or smaller." |
7840ced1 GM |
69 | :type 'integer |
70 | :group 'jit-lock) | |
71 | ||
72 | ||
73 | (defcustom jit-lock-stealth-time 3 | |
74 | "*Time in seconds to wait before beginning stealth fontification. | |
75 | Stealth fontification occurs if there is no input within this time. | |
f86292a9 | 76 | If nil, stealth fontification is never performed. |
7840ced1 GM |
77 | |
78 | The value of this variable is used when JIT Lock mode is turned on." | |
79 | :type '(choice (const :tag "never" nil) | |
80 | (number :tag "seconds")) | |
81 | :group 'jit-lock) | |
82 | ||
83 | ||
84 | (defcustom jit-lock-stealth-nice 0.125 | |
85 | "*Time in seconds to pause between chunks of stealth fontification. | |
86 | Each iteration of stealth fontification is separated by this amount of time, | |
87 | thus reducing the demand that stealth fontification makes on the system. | |
88 | If nil, means stealth fontification is never paused. | |
89 | To reduce machine load during stealth fontification, at the cost of stealth | |
90 | taking longer to fontify, you could increase the value of this variable. | |
91 | See also `jit-lock-stealth-load'." | |
92 | :type '(choice (const :tag "never" nil) | |
f1180544 | 93 | (number :tag "seconds")) |
7840ced1 | 94 | :group 'jit-lock) |
f1180544 | 95 | |
7840ced1 GM |
96 | |
97 | (defcustom jit-lock-stealth-load | |
98 | (if (condition-case nil (load-average) (error)) 200) | |
99 | "*Load in percentage above which stealth fontification is suspended. | |
100 | Stealth fontification pauses when the system short-term load average (as | |
101 | returned by the function `load-average' if supported) goes above this level, | |
102 | thus reducing the demand that stealth fontification makes on the system. | |
103 | If nil, means stealth fontification is never suspended. | |
104 | To reduce machine load during stealth fontification, at the cost of stealth | |
105 | taking longer to fontify, you could reduce the value of this variable. | |
106 | See also `jit-lock-stealth-nice'." | |
107 | :type (if (condition-case nil (load-average) (error)) | |
108 | '(choice (const :tag "never" nil) | |
109 | (integer :tag "load")) | |
110 | '(const :format "%t: unsupported\n" nil)) | |
111 | :group 'jit-lock) | |
112 | ||
113 | ||
114 | (defcustom jit-lock-stealth-verbose nil | |
115 | "*If non-nil, means stealth fontification should show status messages." | |
116 | :type 'boolean | |
117 | :group 'jit-lock) | |
118 | ||
119 | ||
f415f2d7 SM |
120 | (defvaralias 'jit-lock-defer-contextually 'jit-lock-contextually) |
121 | (defcustom jit-lock-contextually 'syntax-driven | |
122 | "*If non-nil, means fontification should be syntactically true. | |
123 | If nil, means fontification occurs only on those lines modified. This | |
7840ced1 GM |
124 | means where modification on a line causes syntactic change on subsequent lines, |
125 | those subsequent lines are not refontified to reflect their new context. | |
f415f2d7 | 126 | If t, means fontification occurs on those lines modified and all |
7840ced1 | 127 | subsequent lines. This means those subsequent lines are refontified to reflect |
7b4d9d3b | 128 | their new syntactic context, after `jit-lock-context-time' seconds. |
f415f2d7 | 129 | If any other value, e.g., `syntax-driven', means syntactically true |
7840ced1 GM |
130 | fontification occurs only if syntactic fontification is performed using the |
131 | buffer mode's syntax table, i.e., only if `font-lock-keywords-only' is nil. | |
132 | ||
133 | The value of this variable is used when JIT Lock mode is turned on." | |
134 | :type '(choice (const :tag "never" nil) | |
135 | (const :tag "always" t) | |
136 | (other :tag "syntax-driven" syntax-driven)) | |
137 | :group 'jit-lock) | |
138 | ||
7b4d9d3b SM |
139 | (defcustom jit-lock-context-time 0.5 |
140 | "Idle time after which text is contextually refontified, if applicable." | |
141 | :type '(number :tag "seconds")) | |
142 | ||
8e069ce2 | 143 | (defcustom jit-lock-defer-time nil ;; 0.25 |
b743187d SM |
144 | "Idle time after which deferred fontification should take place. |
145 | If nil, fontification is not deferred." | |
146 | :group 'jit-lock | |
147 | :type '(choice (const :tag "never" nil) | |
148 | (number :tag "seconds"))) | |
7840ced1 GM |
149 | \f |
150 | ;;; Variables that are not customizable. | |
151 | ||
152 | (defvar jit-lock-mode nil | |
153 | "Non-nil means Just-in-time Lock mode is active.") | |
154 | (make-variable-buffer-local 'jit-lock-mode) | |
155 | ||
be390cb3 SM |
156 | (defvar jit-lock-functions nil |
157 | "Functions to do the actual fontification. | |
158 | They are called with two arguments: the START and END of the region to fontify.") | |
a62e3c6f | 159 | (make-variable-buffer-local 'jit-lock-functions) |
7840ced1 | 160 | |
623a1226 | 161 | (defvar jit-lock-context-unfontify-pos nil |
a62e3c6f | 162 | "Consider text after this position as contextually unfontified. |
bcacade9 | 163 | If nil, contextual fontification is disabled.") |
623a1226 | 164 | (make-variable-buffer-local 'jit-lock-context-unfontify-pos) |
7840ced1 GM |
165 | |
166 | ||
167 | (defvar jit-lock-stealth-timer nil | |
168 | "Timer for stealth fontification in Just-in-time Lock mode.") | |
7b4d9d3b SM |
169 | (defvar jit-lock-context-timer nil |
170 | "Timer for context fontification in Just-in-time Lock mode.") | |
b743187d SM |
171 | (defvar jit-lock-defer-timer nil |
172 | "Timer for deferred fontification in Just-in-time Lock mode.") | |
173 | ||
623a1226 | 174 | (defvar jit-lock-defer-buffers nil |
b743187d | 175 | "List of buffers with pending deferred fontification.") |
7840ced1 GM |
176 | \f |
177 | ;;; JIT lock mode | |
178 | ||
7840ced1 GM |
179 | (defun jit-lock-mode (arg) |
180 | "Toggle Just-in-time Lock mode. | |
bcacade9 | 181 | Turn Just-in-time Lock mode on if and only if ARG is non-nil. |
7840ced1 GM |
182 | Enable it automatically by customizing group `font-lock'. |
183 | ||
184 | When Just-in-time Lock mode is enabled, fontification is different in the | |
185 | following ways: | |
186 | ||
187 | - Demand-driven buffer fontification triggered by Emacs C code. | |
188 | This means initial fontification of the whole buffer does not occur. | |
189 | Instead, fontification occurs when necessary, such as when scrolling | |
190 | through the buffer would otherwise reveal unfontified areas. This is | |
191 | useful if buffer fontification is too slow for large buffers. | |
192 | ||
193 | - Stealthy buffer fontification if `jit-lock-stealth-time' is non-nil. | |
194 | This means remaining unfontified areas of buffers are fontified if Emacs has | |
195 | been idle for `jit-lock-stealth-time' seconds, while Emacs remains idle. | |
196 | This is useful if any buffer has any deferred fontification. | |
197 | ||
f415f2d7 | 198 | - Deferred context fontification if `jit-lock-contextually' is |
7840ced1 | 199 | non-nil. This means fontification updates the buffer corresponding to |
7b4d9d3b | 200 | true syntactic context, after `jit-lock-context-time' seconds of Emacs |
7840ced1 GM |
201 | idle time, while Emacs remains idle. Otherwise, fontification occurs |
202 | on modified lines only, and subsequent lines can remain fontified | |
203 | corresponding to previous syntactic contexts. This is useful where | |
204 | strings or comments span lines. | |
205 | ||
206 | Stealth fontification only occurs while the system remains unloaded. | |
207 | If the system load rises above `jit-lock-stealth-load' percent, stealth | |
208 | fontification is suspended. Stealth fontification intensity is controlled via | |
02b420eb | 209 | the variable `jit-lock-stealth-nice'." |
bcacade9 SM |
210 | (setq jit-lock-mode arg) |
211 | (cond (;; Turn Just-in-time Lock mode on. | |
212 | jit-lock-mode | |
213 | ||
b743187d | 214 | ;; Mark the buffer for refontification. |
a62e3c6f | 215 | (jit-lock-refontify) |
02b420eb | 216 | |
7840ced1 | 217 | ;; Install an idle timer for stealth fontification. |
c94d5f40 | 218 | (when (and jit-lock-stealth-time (null jit-lock-stealth-timer)) |
02b420eb | 219 | (setq jit-lock-stealth-timer |
b743187d | 220 | (run-with-idle-timer jit-lock-stealth-time t |
7840ced1 GM |
221 | 'jit-lock-stealth-fontify))) |
222 | ||
b743187d SM |
223 | ;; Init deferred fontification timer. |
224 | (when (and jit-lock-defer-time (null jit-lock-defer-timer)) | |
225 | (setq jit-lock-defer-timer | |
226 | (run-with-idle-timer jit-lock-defer-time t | |
227 | 'jit-lock-deferred-fontify))) | |
228 | ||
623a1226 | 229 | ;; Initialize contextual fontification if requested. |
f415f2d7 | 230 | (when (eq jit-lock-contextually t) |
7b4d9d3b SM |
231 | (unless jit-lock-context-timer |
232 | (setq jit-lock-context-timer | |
233 | (run-with-idle-timer jit-lock-context-time t | |
234 | 'jit-lock-context-fontify))) | |
623a1226 SM |
235 | (setq jit-lock-context-unfontify-pos |
236 | (or jit-lock-context-unfontify-pos (point-max)))) | |
bcacade9 | 237 | |
a62e3c6f | 238 | ;; Setup our hooks. |
bcacade9 | 239 | (add-hook 'after-change-functions 'jit-lock-after-change nil t) |
7840ced1 GM |
240 | (add-hook 'fontification-functions 'jit-lock-function)) |
241 | ||
242 | ;; Turn Just-in-time Lock mode off. | |
243 | (t | |
b743187d | 244 | ;; Cancel our idle timers. |
7b4d9d3b SM |
245 | (when (and (or jit-lock-stealth-timer jit-lock-defer-timer |
246 | jit-lock-context-timer) | |
b743187d SM |
247 | ;; Only if there's no other buffer using them. |
248 | (not (catch 'found | |
249 | (dolist (buf (buffer-list)) | |
250 | (with-current-buffer buf | |
251 | (when jit-lock-mode (throw 'found t))))))) | |
252 | (when jit-lock-stealth-timer | |
253 | (cancel-timer jit-lock-stealth-timer) | |
254 | (setq jit-lock-stealth-timer nil)) | |
7b4d9d3b SM |
255 | (when jit-lock-context-timer |
256 | (cancel-timer jit-lock-context-timer) | |
257 | (setq jit-lock-context-timer nil)) | |
b743187d SM |
258 | (when jit-lock-defer-timer |
259 | (cancel-timer jit-lock-defer-timer) | |
260 | (setq jit-lock-defer-timer nil))) | |
7840ced1 | 261 | |
a62e3c6f | 262 | ;; Remove hooks. |
02b420eb | 263 | (remove-hook 'after-change-functions 'jit-lock-after-change t) |
7840ced1 GM |
264 | (remove-hook 'fontification-functions 'jit-lock-function)))) |
265 | ||
c94d5f40 SM |
266 | ;;;###autoload |
267 | (defun jit-lock-register (fun &optional contextual) | |
8a677d4f SM |
268 | "Register FUN as a fontification function to be called in this buffer. |
269 | FUN will be called with two arguments START and END indicating the region | |
c94d5f40 SM |
270 | that needs to be (re)fontified. |
271 | If non-nil, CONTEXTUAL means that a contextual fontification would be useful." | |
f8bacc70 | 272 | (add-hook 'jit-lock-functions fun nil t) |
f415f2d7 SM |
273 | (when (and contextual jit-lock-contextually) |
274 | (set (make-local-variable 'jit-lock-contextually) t)) | |
f8bacc70 SM |
275 | (jit-lock-mode t)) |
276 | ||
277 | (defun jit-lock-unregister (fun) | |
8a677d4f | 278 | "Unregister FUN as a fontification function. |
f8bacc70 SM |
279 | Only applies to the current buffer." |
280 | (remove-hook 'jit-lock-functions fun t) | |
a62e3c6f | 281 | (unless jit-lock-functions (jit-lock-mode nil))) |
7840ced1 | 282 | |
02b420eb SM |
283 | ;; This function is used to prevent font-lock-fontify-buffer from |
284 | ;; fontifying eagerly the whole buffer. This is important for | |
285 | ;; things like CWarn mode which adds/removes a few keywords and | |
286 | ;; does a refontify (which takes ages on large files). | |
a62e3c6f SM |
287 | (defun jit-lock-refontify (&optional beg end) |
288 | "Force refontification of the region BEG..END (default whole buffer)." | |
bcacade9 | 289 | (with-buffer-prepared-for-jit-lock |
5a5987eb SM |
290 | (save-restriction |
291 | (widen) | |
b743187d SM |
292 | (put-text-property (or beg (point-min)) (or end (point-max)) |
293 | 'fontified nil)))) | |
7840ced1 GM |
294 | \f |
295 | ;;; On demand fontification. | |
296 | ||
297 | (defun jit-lock-function (start) | |
298 | "Fontify current buffer starting at position START. | |
299 | This function is added to `fontification-functions' when `jit-lock-mode' | |
300 | is active." | |
301 | (when jit-lock-mode | |
b743187d SM |
302 | (if (null jit-lock-defer-time) |
303 | ;; No deferral. | |
304 | (jit-lock-fontify-now start (+ start jit-lock-chunk-size)) | |
305 | ;; Record the buffer for later fontification. | |
623a1226 SM |
306 | (unless (memq (current-buffer) jit-lock-defer-buffers) |
307 | (push (current-buffer) jit-lock-defer-buffers)) | |
b743187d SM |
308 | ;; Mark the area as defer-fontified so that the redisplay engine |
309 | ;; is happy and so that the idle timer can find the places to fontify. | |
310 | (with-buffer-prepared-for-jit-lock | |
311 | (put-text-property start | |
312 | (next-single-property-change | |
313 | start 'fontified nil | |
314 | (min (point-max) (+ start jit-lock-chunk-size))) | |
315 | 'fontified 'defer))))) | |
a62e3c6f SM |
316 | |
317 | (defun jit-lock-fontify-now (&optional start end) | |
318 | "Fontify current buffer from START to END. | |
319 | Defaults to the whole buffer. END can be out of bounds." | |
bcacade9 | 320 | (with-buffer-prepared-for-jit-lock |
60bffb78 | 321 | (save-excursion |
c9cf2e67 SM |
322 | (unless start (setq start (point-min))) |
323 | (setq end (if end (min end (point-max)) (point-max))) | |
324 | ;; This did bind `font-lock-beginning-of-syntax-function' to | |
325 | ;; nil at some point, for an unknown reason. Don't do this; it | |
326 | ;; can make highlighting slow due to expensive calls to | |
327 | ;; `parse-partial-sexp' in function | |
328 | ;; `font-lock-fontify-syntactically-region'. Example: paging | |
329 | ;; from the end of a buffer to its start, can do repeated | |
330 | ;; `parse-partial-sexp' starting from `point-min', which can | |
331 | ;; take a long time in a large buffer. | |
332 | (let (next) | |
333 | (save-match-data | |
334 | ;; Fontify chunks beginning at START. The end of a | |
335 | ;; chunk is either `end', or the start of a region | |
336 | ;; before `end' that has already been fontified. | |
337 | (while start | |
338 | ;; Determine the end of this chunk. | |
339 | (setq next (or (text-property-any start end 'fontified t) | |
340 | end)) | |
341 | ||
342 | ;; Decide which range of text should be fontified. | |
343 | ;; The problem is that START and NEXT may be in the | |
344 | ;; middle of something matched by a font-lock regexp. | |
345 | ;; Until someone has a better idea, let's start | |
346 | ;; at the start of the line containing START and | |
347 | ;; stop at the start of the line following NEXT. | |
348 | (goto-char next) (setq next (line-beginning-position 2)) | |
349 | (goto-char start) (setq start (line-beginning-position)) | |
f1180544 | 350 | |
c9cf2e67 SM |
351 | ;; Fontify the chunk, and mark it as fontified. |
352 | ;; We mark it first, to make sure that we don't indefinitely | |
353 | ;; re-execute this fontification if an error occurs. | |
354 | (put-text-property start next 'fontified t) | |
f415f2d7 SM |
355 | (condition-case err |
356 | (run-hook-with-args 'jit-lock-functions start next) | |
357 | ;; If the user quits (which shouldn't happen in normal on-the-fly | |
358 | ;; jit-locking), make sure the fontification will be performed | |
359 | ;; before displaying the block again. | |
360 | (quit (put-text-property start next 'fontified nil) | |
361 | (funcall 'signal (car err) (cdr err)))) | |
c9cf2e67 SM |
362 | |
363 | ;; Find the start of the next chunk, if any. | |
364 | (setq start (text-property-any next end 'fontified nil)))))))) | |
7840ced1 | 365 | |
7840ced1 GM |
366 | \f |
367 | ;;; Stealth fontification. | |
368 | ||
369 | (defsubst jit-lock-stealth-chunk-start (around) | |
370 | "Return the start of the next chunk to fontify around position AROUND.. | |
371 | Value is nil if there is nothing more to fontify." | |
8c887c51 GM |
372 | (if (zerop (buffer-size)) |
373 | nil | |
374 | (save-restriction | |
375 | (widen) | |
b743187d | 376 | (let* ((next (text-property-not-all around (point-max) 'fontified t)) |
8c887c51 GM |
377 | (prev (previous-single-property-change around 'fontified)) |
378 | (prop (get-text-property (max (point-min) (1- around)) | |
379 | 'fontified)) | |
380 | (start (cond | |
381 | ((null prev) | |
382 | ;; There is no property change between AROUND | |
383 | ;; and the start of the buffer. If PROP is | |
384 | ;; non-nil, everything in front of AROUND is | |
385 | ;; fontified, otherwise nothing is fontified. | |
b743187d | 386 | (if (eq prop t) |
8c887c51 GM |
387 | nil |
388 | (max (point-min) | |
389 | (- around (/ jit-lock-chunk-size 2))))) | |
b743187d | 390 | ((eq prop t) |
8c887c51 | 391 | ;; PREV is the start of a region of fontified |
bcacade9 | 392 | ;; text containing AROUND. Start fontifying a |
8c887c51 GM |
393 | ;; chunk size before the end of the unfontified |
394 | ;; region in front of that. | |
395 | (max (or (previous-single-property-change prev 'fontified) | |
396 | (point-min)) | |
397 | (- prev jit-lock-chunk-size))) | |
398 | (t | |
399 | ;; PREV is the start of a region of unfontified | |
400 | ;; text containing AROUND. Start at PREV or | |
401 | ;; chunk size in front of AROUND, whichever is | |
402 | ;; nearer. | |
403 | (max prev (- around jit-lock-chunk-size))))) | |
404 | (result (cond ((null start) next) | |
405 | ((null next) start) | |
406 | ((< (- around start) (- next around)) start) | |
407 | (t next)))) | |
408 | result)))) | |
f1180544 | 409 | |
7840ced1 GM |
410 | |
411 | (defun jit-lock-stealth-fontify () | |
412 | "Fontify buffers stealthily. | |
413 | This functions is called after Emacs has been idle for | |
414 | `jit-lock-stealth-time' seconds." | |
b743187d | 415 | ;; I used to check `inhibit-read-only' here, but I can't remember why. -stef |
7840ced1 GM |
416 | (unless (or executing-kbd-macro |
417 | (window-minibuffer-p (selected-window))) | |
418 | (let ((buffers (buffer-list)) | |
419 | minibuffer-auto-raise | |
420 | message-log-max) | |
f415f2d7 SM |
421 | (with-local-quit |
422 | (while (and buffers (not (input-pending-p))) | |
423 | (with-current-buffer (pop buffers) | |
7840ced1 GM |
424 | (when jit-lock-mode |
425 | ;; This is funny. Calling sit-for with 3rd arg non-nil | |
426 | ;; so that it doesn't redisplay, internally calls | |
427 | ;; wait_reading_process_input also with a parameter | |
428 | ;; saying "don't redisplay." Since this function here | |
429 | ;; is called periodically, this effectively leads to | |
430 | ;; process output not being redisplayed at all because | |
431 | ;; redisplay_internal is never called. (That didn't | |
432 | ;; work in the old redisplay either.) So, we learn that | |
433 | ;; we mustn't call sit-for that way here. But then, we | |
434 | ;; have to be cautious not to call sit-for in a widened | |
435 | ;; buffer, since this could display hidden parts of that | |
436 | ;; buffer. This explains the seemingly weird use of | |
437 | ;; save-restriction/widen here. | |
438 | ||
439 | (with-temp-message (if jit-lock-stealth-verbose | |
440 | (concat "JIT stealth lock " | |
441 | (buffer-name))) | |
8c887c51 | 442 | |
9f1a8fb4 GM |
443 | ;; In the following code, the `sit-for' calls cause a |
444 | ;; redisplay, so it's required that the | |
445 | ;; buffer-modified flag of a buffer that is displayed | |
446 | ;; has the right value---otherwise the mode line of | |
447 | ;; an unmodified buffer would show a `*'. | |
448 | (let (start | |
449 | (nice (or jit-lock-stealth-nice 0)) | |
b743187d | 450 | (point (point-min))) |
9f1a8fb4 GM |
451 | (while (and (setq start |
452 | (jit-lock-stealth-chunk-start point)) | |
453 | (sit-for nice)) | |
f1180544 | 454 | |
b743187d SM |
455 | ;; fontify a block. |
456 | (jit-lock-fontify-now start (+ start jit-lock-chunk-size)) | |
457 | ;; If stealth jit-locking is done backwards, this leads to | |
458 | ;; excessive O(n^2) refontification. -stef | |
623a1226 SM |
459 | ;; (when (>= jit-lock-context-unfontify-pos start) |
460 | ;; (setq jit-lock-context-unfontify-pos end)) | |
f1180544 | 461 | |
9f1a8fb4 GM |
462 | ;; Wait a little if load is too high. |
463 | (when (and jit-lock-stealth-load | |
464 | (> (car (load-average)) jit-lock-stealth-load)) | |
b743187d | 465 | (sit-for (or jit-lock-stealth-time 30))))))))))))) |
7840ced1 GM |
466 | |
467 | ||
468 | \f | |
469 | ;;; Deferred fontification. | |
470 | ||
b743187d SM |
471 | (defun jit-lock-deferred-fontify () |
472 | "Fontify what was deferred." | |
623a1226 | 473 | (when jit-lock-defer-buffers |
b743187d | 474 | ;; Mark the deferred regions back to `fontified = nil' |
623a1226 | 475 | (dolist (buffer jit-lock-defer-buffers) |
b743187d SM |
476 | (when (buffer-live-p buffer) |
477 | (with-current-buffer buffer | |
478 | ;; (message "Jit-Defer %s" (buffer-name)) | |
479 | (with-buffer-prepared-for-jit-lock | |
480 | (let ((pos (point-min))) | |
481 | (while | |
482 | (progn | |
483 | (when (eq (get-text-property pos 'fontified) 'defer) | |
484 | (put-text-property | |
485 | pos (setq pos (next-single-property-change | |
486 | pos 'fontified nil (point-max))) | |
487 | 'fontified nil)) | |
488 | (setq pos (next-single-property-change pos 'fontified))))))))) | |
623a1226 | 489 | (setq jit-lock-defer-buffers nil) |
b743187d SM |
490 | ;; Force fontification of the visible parts. |
491 | (let ((jit-lock-defer-time nil)) | |
492 | ;; (message "Jit-Defer Now") | |
493 | (sit-for 0) | |
494 | ;; (message "Jit-Defer Done") | |
495 | ))) | |
f1180544 | 496 | |
b743187d | 497 | |
7b4d9d3b SM |
498 | (defun jit-lock-context-fontify () |
499 | "Refresh fontification to take new context into account." | |
500 | (dolist (buffer (buffer-list)) | |
501 | (with-current-buffer buffer | |
502 | (when jit-lock-context-unfontify-pos | |
503 | ;; (message "Jit-Context %s" (buffer-name)) | |
504 | (save-restriction | |
505 | (widen) | |
506 | (when (and (>= jit-lock-context-unfontify-pos (point-min)) | |
507 | (< jit-lock-context-unfontify-pos (point-max))) | |
508 | ;; If we're in text that matches a complex multi-line | |
509 | ;; font-lock pattern, make sure the whole text will be | |
510 | ;; redisplayed eventually. | |
511 | ;; Despite its name, we treat jit-lock-defer-multiline here | |
512 | ;; rather than in jit-lock-defer since it has to do with multiple | |
513 | ;; lines, i.e. with context. | |
514 | (when (get-text-property jit-lock-context-unfontify-pos | |
515 | 'jit-lock-defer-multiline) | |
516 | (setq jit-lock-context-unfontify-pos | |
517 | (or (previous-single-property-change | |
518 | jit-lock-context-unfontify-pos | |
519 | 'jit-lock-defer-multiline) | |
520 | (point-min)))) | |
521 | (with-buffer-prepared-for-jit-lock | |
522 | ;; Force contextual refontification. | |
523 | (remove-text-properties | |
524 | jit-lock-context-unfontify-pos (point-max) | |
525 | '(fontified nil jit-lock-defer-multiline nil))) | |
526 | (setq jit-lock-context-unfontify-pos (point-max)))))))) | |
527 | ||
7840ced1 GM |
528 | (defun jit-lock-after-change (start end old-len) |
529 | "Mark the rest of the buffer as not fontified after a change. | |
530 | Installed on `after-change-functions'. | |
531 | START and END are the start and end of the changed text. OLD-LEN | |
532 | is the pre-change length. | |
533 | This function ensures that lines following the change will be refontified | |
534 | in case the syntax of those lines has changed. Refontification | |
535 | will take place when text is fontified stealthily." | |
7840ced1 | 536 | (when jit-lock-mode |
d9330f43 SM |
537 | (save-excursion |
538 | (with-buffer-prepared-for-jit-lock | |
539 | ;; It's important that the `fontified' property be set from the | |
540 | ;; beginning of the line, else font-lock will properly change the | |
541 | ;; text's face, but the display will have been done already and will | |
542 | ;; be inconsistent with the buffer's content. | |
543 | (goto-char start) | |
544 | (setq start (line-beginning-position)) | |
f1180544 | 545 | |
df22166e SM |
546 | ;; If we're in text that matches a multi-line font-lock pattern, |
547 | ;; make sure the whole text will be redisplayed. | |
b743187d | 548 | ;; I'm not sure this is ever necessary and/or sufficient. -stef |
df22166e SM |
549 | (when (get-text-property start 'font-lock-multiline) |
550 | (setq start (or (previous-single-property-change | |
551 | start 'font-lock-multiline) | |
552 | (point-min)))) | |
f1180544 | 553 | |
d9330f43 SM |
554 | ;; Make sure we change at least one char (in case of deletions). |
555 | (setq end (min (max end (1+ start)) (point-max))) | |
556 | ;; Request refontification. | |
557 | (put-text-property start end 'fontified nil)) | |
558 | ;; Mark the change for deferred contextual refontification. | |
623a1226 SM |
559 | (when jit-lock-context-unfontify-pos |
560 | (setq jit-lock-context-unfontify-pos | |
561 | (min jit-lock-context-unfontify-pos start)))))) | |
f1180544 | 562 | |
7840ced1 GM |
563 | (provide 'jit-lock) |
564 | ||
ab5796a9 | 565 | ;;; arch-tag: 56b5de6e-f581-453b-bb97-49c39372ff9e |
e8af40ee | 566 | ;;; jit-lock.el ends here |