;;; jit-lock.el --- just-in-time fontification
;; Copyright (C) 1998, 2000, 2001, 2002, 2003, 2004,
-;; 2005 Free Software Foundation, Inc.
+;; 2005, 2006, 2007 Free Software Foundation, Inc.
;; Author: Gerd Moellmann <gerd@gnu.org>
;; Keywords: faces files
(eval-when-compile
+ (require 'cl)
+
(defmacro with-buffer-unmodified (&rest body)
"Eval BODY, preserving the current buffer's modified state."
(declare (debug t))
:group 'font-lock)
(defcustom jit-lock-chunk-size 500
- "*Jit-lock chunks of this many characters, or smaller."
+ "*Jit-lock fontifies chunks of at most this many characters at a time.
+
+This variable controls both display-time and stealth fontification."
:type 'integer
:group 'jit-lock)
(defvar jit-lock-stealth-timer nil
"Timer for stealth fontification in Just-in-time Lock mode.")
+(defvar jit-lock-stealth-repeat-timer nil
+ "Timer for repeated stealth fontification in Just-in-time Lock mode.")
(defvar jit-lock-context-timer nil
"Timer for context fontification in Just-in-time Lock mode.")
(defvar jit-lock-defer-timer nil
(defvar jit-lock-defer-buffers nil
"List of buffers with pending deferred fontification.")
+(defvar jit-lock-stealth-buffers nil
+ "List of buffers that are being fontified stealthily.")
\f
;;; JIT lock mode
(run-with-idle-timer jit-lock-stealth-time t
'jit-lock-stealth-fontify)))
+ ;; Create, but do not activate, the idle timer for repeated
+ ;; stealth fontification.
+ (when (and jit-lock-stealth-time (null jit-lock-stealth-repeat-timer))
+ (setq jit-lock-stealth-repeat-timer (timer-create))
+ (timer-set-function jit-lock-stealth-repeat-timer
+ 'jit-lock-stealth-fontify '(t)))
+
;; Init deferred fontification timer.
(when (and jit-lock-defer-time (null jit-lock-defer-timer))
(setq jit-lock-defer-timer
This function is added to `fontification-functions' when `jit-lock-mode'
is active."
(when (and jit-lock-mode (not memory-full))
- (if (null jit-lock-defer-time)
+ (if (null jit-lock-defer-timer)
;; No deferral.
(jit-lock-fontify-now start (+ start jit-lock-chunk-size))
;; Record the buffer for later fontification.
;; from the end of a buffer to its start, can do repeated
;; `parse-partial-sexp' starting from `point-min', which can
;; take a long time in a large buffer.
- (let (next)
+ (let ((orig-start start) next)
(save-match-data
;; Fontify chunks beginning at START. The end of a
;; chunk is either `end', or the start of a region
;; before `end' that has already been fontified.
- (while start
+ (while (and start (< start end))
;; Determine the end of this chunk.
(setq next (or (text-property-any start end 'fontified t)
end))
(quit (put-text-property start next 'fontified nil)
(funcall 'signal (car err) (cdr err))))
+ ;; The redisplay engine has already rendered the buffer up-to
+ ;; `orig-start' and won't notice if the above jit-lock-functions
+ ;; changed the appearance of any part of the buffer prior
+ ;; to that. So if `start' is before `orig-start', we need to
+ ;; cause a new redisplay cycle after this one so that any changes
+ ;; are properly reflected on screen.
+ ;; To make such repeated redisplay happen less often, we can
+ ;; eagerly extend the refontified region with
+ ;; jit-lock-after-change-extend-region-functions.
+ (when (< start orig-start)
+ (run-with-timer 0 nil 'jit-lock-force-redisplay
+ (current-buffer) start orig-start))
+
;; Find the start of the next chunk, if any.
(setq start (text-property-any next end 'fontified nil))))))))
+(defun jit-lock-force-redisplay (buf start end)
+ "Force the display engine to re-render buffer BUF from START to END."
+ (with-current-buffer buf
+ (with-buffer-prepared-for-jit-lock
+ ;; Don't cause refontification (it's already been done), but just do
+ ;; some random buffer change, so as to force redisplay.
+ (put-text-property start end 'fontified t))))
+
+
\f
;;; Stealth fontification.
(t next))))
result))))
-
-(defun jit-lock-stealth-fontify ()
+(defun jit-lock-stealth-fontify (&optional repeat)
"Fontify buffers stealthily.
-This functions is called after Emacs has been idle for
-`jit-lock-stealth-time' seconds."
- ;; I used to check `inhibit-read-only' here, but I can't remember why. -stef
+This function is called repeatedly after Emacs has become idle for
+`jit-lock-stealth-time' seconds. Optional argument REPEAT is expected
+non-nil in a repeated invocation of this function."
+ ;; Cancel timer for repeated invocations.
+ (unless repeat
+ (cancel-timer jit-lock-stealth-repeat-timer))
(unless (or executing-kbd-macro
memory-full
- (window-minibuffer-p (selected-window)))
- (let ((buffers (buffer-list))
- (outer-buffer (current-buffer))
+ (window-minibuffer-p (selected-window))
+ ;; For first invocation set up `jit-lock-stealth-buffers'.
+ ;; In repeated invocations it's already been set up.
+ (null (if repeat
+ jit-lock-stealth-buffers
+ (setq jit-lock-stealth-buffers (buffer-list)))))
+ (let ((buffer (car jit-lock-stealth-buffers))
+ (delay 0)
minibuffer-auto-raise
- message-log-max)
- (with-local-quit
- (while (and buffers (not (input-pending-p)))
- (with-current-buffer (pop buffers)
- (when jit-lock-mode
- ;; This is funny. Calling sit-for with 3rd arg non-nil
- ;; so that it doesn't redisplay, internally calls
- ;; wait_reading_process_input also with a parameter
- ;; saying "don't redisplay." Since this function here
- ;; is called periodically, this effectively leads to
- ;; process output not being redisplayed at all because
- ;; redisplay_internal is never called. (That didn't
- ;; work in the old redisplay either.) So, we learn that
- ;; we mustn't call sit-for that way here. But then, we
- ;; have to be cautious not to call sit-for in a widened
- ;; buffer, since this could display hidden parts of that
- ;; buffer. This explains the seemingly weird use of
- ;; save-restriction/widen here.
-
- (with-temp-message (if jit-lock-stealth-verbose
- (concat "JIT stealth lock "
- (buffer-name)))
-
- ;; In the following code, the `sit-for' calls cause a
- ;; redisplay, so it's required that the
- ;; buffer-modified flag of a buffer that is displayed
- ;; has the right value---otherwise the mode line of
- ;; an unmodified buffer would show a `*'.
- (let (start
- (nice (or jit-lock-stealth-nice 0))
- (point (point-min)))
- (while (and (setq start
- (jit-lock-stealth-chunk-start point))
- ;; In case sit-for runs any timers,
- ;; give them the expected current buffer.
- (with-current-buffer outer-buffer
- (sit-for nice)))
-
- ;; fontify a block.
- (jit-lock-fontify-now start (+ start jit-lock-chunk-size))
- ;; If stealth jit-locking is done backwards, this leads to
- ;; excessive O(n^2) refontification. -stef
- ;; (when (>= jit-lock-context-unfontify-pos start)
- ;; (setq jit-lock-context-unfontify-pos end))
-
- ;; Wait a little if load is too high.
- (when (and jit-lock-stealth-load
- (> (car (load-average)) jit-lock-stealth-load))
- ;; In case sit-for runs any timers,
- ;; give them the expected current buffer.
- (with-current-buffer outer-buffer
- (sit-for (or jit-lock-stealth-time 30))))))))))))))
-
+ message-log-max
+ start)
+ (if (and jit-lock-stealth-load
+ (> (car (load-average)) jit-lock-stealth-load))
+ ;; Wait a little if load is too high.
+ (setq delay jit-lock-stealth-time)
+ (if (buffer-live-p buffer)
+ (with-current-buffer buffer
+ (if (and jit-lock-mode
+ (setq start (jit-lock-stealth-chunk-start (point))))
+ ;; Fontify one block of at most `jit-lock-chunk-size'
+ ;; characters.
+ (with-temp-message (if jit-lock-stealth-verbose
+ (concat "JIT stealth lock "
+ (buffer-name)))
+ (jit-lock-fontify-now start
+ (+ start jit-lock-chunk-size))
+ ;; Run again after `jit-lock-stealth-nice' seconds.
+ (setq delay (or jit-lock-stealth-nice 0)))
+ ;; Nothing to fontify here. Remove this buffer from
+ ;; `jit-lock-stealth-buffers' and run again immediately.
+ (setq jit-lock-stealth-buffers (cdr jit-lock-stealth-buffers))))
+ ;; Buffer is no longer live. Remove it from
+ ;; `jit-lock-stealth-buffers' and run again immediately.
+ (setq jit-lock-stealth-buffers (cdr jit-lock-stealth-buffers))))
+ ;; Call us again.
+ (when jit-lock-stealth-buffers
+ (timer-set-idle-time jit-lock-stealth-repeat-timer (current-idle-time))
+ (timer-inc-time jit-lock-stealth-repeat-timer delay)
+ (timer-activate-when-idle jit-lock-stealth-repeat-timer t)))))
\f
;;; Deferred fontification.
(setq pos (next-single-property-change pos 'fontified)))))))))
(setq jit-lock-defer-buffers nil)
;; Force fontification of the visible parts.
- (let ((jit-lock-defer-time nil))
+ (let ((jit-lock-defer-timer nil))
;; (message "Jit-Defer Now")
(sit-for 0)
;; (message "Jit-Defer Done")
'(fontified nil jit-lock-defer-multiline nil)))
(setq jit-lock-context-unfontify-pos (point-max)))))))))
+(defvar jit-lock-start) (defvar jit-lock-end) ; Dynamically scoped variables.
+(defvar jit-lock-after-change-extend-region-functions nil
+ "Hook that can extend the text to refontify after a change.
+This is run after every buffer change. The functions are called with
+the three arguments of `after-change-functions': START END OLD-LEN.
+The extended region to refontify is returned indirectly by modifying
+the variables `jit-lock-start' and `jit-lock-end'.
+
+Note that extending the region this way is not strictly necessary, except
+that the nature of the redisplay code tends to otherwise leave some of
+the rehighlighted text displayed with the old highlight until the next
+redisplay (see comment about repeated redisplay in `jit-lock-fontify-now').")
+
(defun jit-lock-after-change (start end old-len)
"Mark the rest of the buffer as not fontified after a change.
Installed on `after-change-functions'.
in case the syntax of those lines has changed. Refontification
will take place when text is fontified stealthily."
(when (and jit-lock-mode (not memory-full))
- (save-excursion
+ (let ((jit-lock-start start)
+ (jit-lock-end end))
(with-buffer-prepared-for-jit-lock
- ;; It's important that the `fontified' property be set from the
- ;; beginning of the line, else font-lock will properly change the
- ;; text's face, but the display will have been done already and will
- ;; be inconsistent with the buffer's content.
- (goto-char start)
- (setq start (line-beginning-position))
-
- ;; If we're in text that matches a multi-line font-lock pattern,
- ;; make sure the whole text will be redisplayed.
- ;; I'm not sure this is ever necessary and/or sufficient. -stef
- (when (get-text-property start 'font-lock-multiline)
- (setq start (or (previous-single-property-change
- start 'font-lock-multiline)
- (point-min))))
-
- ;; Make sure we change at least one char (in case of deletions).
- (setq end (min (max end (1+ start)) (point-max)))
- ;; Request refontification.
- (put-text-property start end 'fontified nil))
+ (run-hook-with-args 'jit-lock-after-change-extend-region-functions
+ start end old-len)
+ ;; Make sure we change at least one char (in case of deletions).
+ (setq jit-lock-end (min (max jit-lock-end (1+ start)) (point-max)))
+ ;; Request refontification.
+ (put-text-property jit-lock-start jit-lock-end 'fontified nil))
;; Mark the change for deferred contextual refontification.
(when jit-lock-context-unfontify-pos
- (setq jit-lock-context-unfontify-pos
+ (setq jit-lock-context-unfontify-pos
;; Here we use `start' because nothing guarantees that the
;; text between start and end will be otherwise refontified:
;; usually it will be refontified by virtue of being
;; displayed, but if it's outside of any displayed area in the
;; buffer, only jit-lock-context-* will re-fontify it.
- (min jit-lock-context-unfontify-pos start))))))
+ (min jit-lock-context-unfontify-pos jit-lock-start))))))
(provide 'jit-lock)