;;; jit-lock.el --- just-in-time fontification
-;; Copyright (C) 1998, 2000, 2001 Free Software Foundation, Inc.
+;; Copyright (C) 1998, 2000, 2001, 2002, 2003, 2004,
+;; 2005, 2006 Free Software Foundation, Inc.
;; Author: Gerd Moellmann <gerd@gnu.org>
;; Keywords: faces files
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING. If not, write to the
-;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-;; Boston, MA 02111-1307, USA.
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
;;; Commentary:
(eval-when-compile
(defmacro with-buffer-unmodified (&rest body)
"Eval BODY, preserving the current buffer's modified state."
+ (declare (debug t))
(let ((modified (make-symbol "modified")))
`(let ((,modified (buffer-modified-p)))
(unwind-protect
(progn ,@body)
(unless ,modified
(restore-buffer-modified-p nil))))))
-
+
(defmacro with-buffer-prepared-for-jit-lock (&rest body)
"Execute BODY in current buffer, overriding several variables.
Preserves the `buffer-modified-p' state of the current buffer."
+ (declare (debug t))
`(with-buffer-unmodified
(let ((buffer-undo-list t)
(inhibit-read-only t)
buffer-file-truename)
,@body))))
-
+
\f
;;; Customization.
+(defgroup jit-lock nil
+ "Font Lock support mode to fontify just-in-time."
+ :version "21.1"
+ :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)
-(defcustom jit-lock-stealth-time 3
+(defcustom jit-lock-stealth-time 16
"*Time in seconds to wait before beginning stealth fontification.
Stealth fontification occurs if there is no input within this time.
If nil, stealth fontification is never performed.
:group 'jit-lock)
-(defcustom jit-lock-stealth-nice 0.125
+(defcustom jit-lock-stealth-nice 0.5
"*Time in seconds to pause between chunks of stealth fontification.
Each iteration of stealth fontification is separated by this amount of time,
thus reducing the demand that stealth fontification makes on the system.
taking longer to fontify, you could increase the value of this variable.
See also `jit-lock-stealth-load'."
:type '(choice (const :tag "never" nil)
- (number :tag "seconds"))
+ (number :tag "seconds"))
:group 'jit-lock)
-
+
(defcustom jit-lock-stealth-load
(if (condition-case nil (load-average) (error)) 200)
:group 'jit-lock)
-(defcustom jit-lock-defer-contextually 'syntax-driven
- "*If non-nil, means deferred fontification should be syntactically true.
-If nil, means deferred fontification occurs only on those lines modified. This
+(defvaralias 'jit-lock-defer-contextually 'jit-lock-contextually)
+(defcustom jit-lock-contextually 'syntax-driven
+ "*If non-nil, means fontification should be syntactically true.
+If nil, means fontification occurs only on those lines modified. This
means where modification on a line causes syntactic change on subsequent lines,
those subsequent lines are not refontified to reflect their new context.
-If t, means deferred fontification occurs on those lines modified and all
+If t, means fontification occurs on those lines modified and all
subsequent lines. This means those subsequent lines are refontified to reflect
-their new syntactic context, either immediately or when scrolling into them.
-If any other value, e.g., `syntax-driven', means deferred syntactically true
+their new syntactic context, after `jit-lock-context-time' seconds.
+If any other value, e.g., `syntax-driven', means syntactically true
fontification occurs only if syntactic fontification is performed using the
buffer mode's syntax table, i.e., only if `font-lock-keywords-only' is nil.
(other :tag "syntax-driven" syntax-driven))
:group 'jit-lock)
+(defcustom jit-lock-context-time 0.5
+ "Idle time after which text is contextually refontified, if applicable."
+ :type '(number :tag "seconds")
+ :group 'jit-lock)
+
(defcustom jit-lock-defer-time nil ;; 0.25
"Idle time after which deferred fontification should take place.
If nil, fontification is not deferred."
They are called with two arguments: the START and END of the region to fontify.")
(make-variable-buffer-local 'jit-lock-functions)
-(defvar jit-lock-first-unfontify-pos nil
+(defvar jit-lock-context-unfontify-pos nil
"Consider text after this position as contextually unfontified.
If nil, contextual fontification is disabled.")
-(make-variable-buffer-local 'jit-lock-first-unfontify-pos)
+(make-variable-buffer-local 'jit-lock-context-unfontify-pos)
(defvar jit-lock-stealth-timer nil
"Timer for 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
"Timer for deferred fontification in Just-in-time Lock mode.")
-(defvar jit-lock-buffers nil
+(defvar jit-lock-defer-buffers nil
"List of buffers with pending deferred fontification.")
\f
;;; JIT lock mode
been idle for `jit-lock-stealth-time' seconds, while Emacs remains idle.
This is useful if any buffer has any deferred fontification.
-- Deferred context fontification if `jit-lock-defer-contextually' is
+- Deferred context fontification if `jit-lock-contextually' is
non-nil. This means fontification updates the buffer corresponding to
- true syntactic context, after `jit-lock-stealth-time' seconds of Emacs
+ true syntactic context, after `jit-lock-context-time' seconds of Emacs
idle time, while Emacs remains idle. Otherwise, fontification occurs
on modified lines only, and subsequent lines can remain fontified
corresponding to previous syntactic contexts. This is useful where
(run-with-idle-timer jit-lock-defer-time t
'jit-lock-deferred-fontify)))
- ;; Initialize deferred contextual fontification if requested.
- (when (eq jit-lock-defer-contextually t)
- (setq jit-lock-first-unfontify-pos
- (or jit-lock-first-unfontify-pos (point-max))))
+ ;; Initialize contextual fontification if requested.
+ (when (eq jit-lock-contextually t)
+ (unless jit-lock-context-timer
+ (setq jit-lock-context-timer
+ (run-with-idle-timer jit-lock-context-time t
+ 'jit-lock-context-fontify)))
+ (setq jit-lock-context-unfontify-pos
+ (or jit-lock-context-unfontify-pos (point-max))))
;; Setup our hooks.
(add-hook 'after-change-functions 'jit-lock-after-change nil t)
;; Turn Just-in-time Lock mode off.
(t
;; Cancel our idle timers.
- (when (and (or jit-lock-stealth-timer jit-lock-defer-timer)
+ (when (and (or jit-lock-stealth-timer jit-lock-defer-timer
+ jit-lock-context-timer)
;; Only if there's no other buffer using them.
(not (catch 'found
(dolist (buf (buffer-list))
(when jit-lock-stealth-timer
(cancel-timer jit-lock-stealth-timer)
(setq jit-lock-stealth-timer nil))
+ (when jit-lock-context-timer
+ (cancel-timer jit-lock-context-timer)
+ (setq jit-lock-context-timer nil))
(when jit-lock-defer-timer
(cancel-timer jit-lock-defer-timer)
(setq jit-lock-defer-timer nil)))
(remove-hook 'after-change-functions 'jit-lock-after-change t)
(remove-hook 'fontification-functions 'jit-lock-function))))
-;;;###autoload
(defun jit-lock-register (fun &optional contextual)
"Register FUN as a fontification function to be called in this buffer.
FUN will be called with two arguments START and END indicating the region
that needs to be (re)fontified.
If non-nil, CONTEXTUAL means that a contextual fontification would be useful."
(add-hook 'jit-lock-functions fun nil t)
- (when (and contextual jit-lock-defer-contextually)
- (set (make-local-variable 'jit-lock-defer-contextually) t))
+ (when (and contextual jit-lock-contextually)
+ (set (make-local-variable 'jit-lock-contextually) t))
(jit-lock-mode t))
(defun jit-lock-unregister (fun)
"Fontify current buffer starting at position START.
This function is added to `fontification-functions' when `jit-lock-mode'
is active."
- (when jit-lock-mode
- (if (null jit-lock-defer-time)
+ (when (and jit-lock-mode (not memory-full))
+ (if (null jit-lock-defer-timer)
;; No deferral.
(jit-lock-fontify-now start (+ start jit-lock-chunk-size))
;; Record the buffer for later fontification.
- (unless (memq (current-buffer) jit-lock-buffers)
- (push (current-buffer) jit-lock-buffers))
+ (unless (memq (current-buffer) jit-lock-defer-buffers)
+ (push (current-buffer) jit-lock-defer-buffers))
;; Mark the area as defer-fontified so that the redisplay engine
;; is happy and so that the idle timer can find the places to fontify.
(with-buffer-prepared-for-jit-lock
Defaults to the whole buffer. END can be out of bounds."
(with-buffer-prepared-for-jit-lock
(save-excursion
- (save-restriction
- (widen)
- (unless start (setq start (point-min)))
- (setq end (if end (min end (point-max)) (point-max)))
- ;; This did bind `font-lock-beginning-of-syntax-function' to
- ;; nil at some point, for an unknown reason. Don't do this; it
- ;; can make highlighting slow due to expensive calls to
- ;; `parse-partial-sexp' in function
- ;; `font-lock-fontify-syntactically-region'. Example: paging
- ;; 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)
- (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
- ;; Determine the end of this chunk.
- (setq next (or (text-property-any start end 'fontified t)
- end))
-
- ;; Decide which range of text should be fontified.
- ;; The problem is that START and NEXT may be in the
- ;; middle of something matched by a font-lock regexp.
- ;; Until someone has a better idea, let's start
- ;; at the start of the line containing START and
- ;; stop at the start of the line following NEXT.
- (goto-char next) (setq next (line-beginning-position 2))
- (goto-char start) (setq start (line-beginning-position))
-
- ;; Fontify the chunk, and mark it as fontified.
- ;; We mark it first, to make sure that we don't indefinitely
- ;; re-execute this fontification if an error occurs.
- (put-text-property start next 'fontified t)
- (run-hook-with-args 'jit-lock-functions start next)
-
- ;; Find the start of the next chunk, if any.
- (setq start (text-property-any next end 'fontified nil)))))))))
+ (unless start (setq start (point-min)))
+ (setq end (if end (min end (point-max)) (point-max)))
+ ;; This did bind `font-lock-beginning-of-syntax-function' to
+ ;; nil at some point, for an unknown reason. Don't do this; it
+ ;; can make highlighting slow due to expensive calls to
+ ;; `parse-partial-sexp' in function
+ ;; `font-lock-fontify-syntactically-region'. Example: paging
+ ;; 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)
+ (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
+ ;; Determine the end of this chunk.
+ (setq next (or (text-property-any start end 'fontified t)
+ end))
+
+ ;; Decide which range of text should be fontified.
+ ;; The problem is that START and NEXT may be in the
+ ;; middle of something matched by a font-lock regexp.
+ ;; Until someone has a better idea, let's start
+ ;; at the start of the line containing START and
+ ;; stop at the start of the line following NEXT.
+ (goto-char next) (setq next (line-beginning-position 2))
+ (goto-char start) (setq start (line-beginning-position))
+
+ ;; Make sure the contextual refontification doesn't re-refontify
+ ;; what's already been refontified.
+ (when (and jit-lock-context-unfontify-pos
+ (< jit-lock-context-unfontify-pos next)
+ (>= jit-lock-context-unfontify-pos start)
+ ;; Don't move boundary forward if we have to
+ ;; refontify previous text. Otherwise, we risk moving
+ ;; it past the end of the multiline property and thus
+ ;; forget about this multiline region altogether.
+ (not (get-text-property start 'jit-lock-defer-multiline)))
+ (setq jit-lock-context-unfontify-pos next))
+
+ ;; Fontify the chunk, and mark it as fontified.
+ ;; We mark it first, to make sure that we don't indefinitely
+ ;; re-execute this fontification if an error occurs.
+ (put-text-property start next 'fontified t)
+ (condition-case err
+ (run-hook-with-args 'jit-lock-functions start next)
+ ;; If the user quits (which shouldn't happen in normal on-the-fly
+ ;; jit-locking), make sure the fontification will be performed
+ ;; before displaying the block again.
+ (quit (put-text-property start next 'fontified nil)
+ (funcall 'signal (car err) (cdr err))))
+
+ ;; Find the start of the next chunk, if any.
+ (setq start (text-property-any next end 'fontified nil))))))))
\f
;;; Stealth fontification.
((< (- around start) (- next around)) start)
(t next))))
result))))
-
+
(defun jit-lock-stealth-fontify ()
"Fontify buffers stealthily.
`jit-lock-stealth-time' seconds."
;; I used to check `inhibit-read-only' here, but I can't remember why. -stef
(unless (or executing-kbd-macro
+ memory-full
(window-minibuffer-p (selected-window)))
(let ((buffers (buffer-list))
+ (outer-buffer (current-buffer))
minibuffer-auto-raise
message-log-max)
- (while (and buffers (not (input-pending-p)))
- (let ((buffer (car buffers)))
- (setq buffers (cdr buffers))
-
- (with-current-buffer buffer
+ (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
(concat "JIT stealth lock "
(buffer-name)))
- ;; Perform deferred unfontification, if any.
- (when jit-lock-first-unfontify-pos
- (save-restriction
- (widen)
- (when (and (>= jit-lock-first-unfontify-pos (point-min))
- (< jit-lock-first-unfontify-pos (point-max)))
- ;; If we're in text that matches a complex multi-line
- ;; font-lock pattern, make sure the whole text will be
- ;; redisplayed eventually.
- (when (get-text-property jit-lock-first-unfontify-pos
- 'jit-lock-defer-multiline)
- (setq jit-lock-first-unfontify-pos
- (or (previous-single-property-change
- jit-lock-first-unfontify-pos
- 'jit-lock-defer-multiline)
- (point-min))))
- (with-buffer-prepared-for-jit-lock
- (remove-text-properties
- jit-lock-first-unfontify-pos (point-max)
- '(fontified nil jit-lock-defer-multiline nil)))
- (setq jit-lock-first-unfontify-pos (point-max)))))
-
;; 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
(point (point-min)))
(while (and (setq start
(jit-lock-stealth-chunk-start point))
- (sit-for nice))
-
+ ;; 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-first-unfontify-pos start)
- ;; (setq jit-lock-first-unfontify-pos end))
-
+ ;; (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))
- (sit-for (or jit-lock-stealth-time 30)))))))))))))
+ ;; 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))))))))))))))
\f
(defun jit-lock-deferred-fontify ()
"Fontify what was deferred."
- (when jit-lock-buffers
+ (when (and jit-lock-defer-buffers (not memory-full))
;; Mark the deferred regions back to `fontified = nil'
- (dolist (buffer jit-lock-buffers)
+ (dolist (buffer jit-lock-defer-buffers)
(when (buffer-live-p buffer)
(with-current-buffer buffer
;; (message "Jit-Defer %s" (buffer-name))
pos 'fontified nil (point-max)))
'fontified nil))
(setq pos (next-single-property-change pos 'fontified)))))))))
- (setq jit-lock-buffers nil)
+ (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")
)))
-
+
+
+(defun jit-lock-context-fontify ()
+ "Refresh fontification to take new context into account."
+ (unless memory-full
+ (dolist (buffer (buffer-list))
+ (with-current-buffer buffer
+ (when jit-lock-context-unfontify-pos
+ ;; (message "Jit-Context %s" (buffer-name))
+ (save-restriction
+ (widen)
+ (when (and (>= jit-lock-context-unfontify-pos (point-min))
+ (< jit-lock-context-unfontify-pos (point-max)))
+ ;; If we're in text that matches a complex multi-line
+ ;; font-lock pattern, make sure the whole text will be
+ ;; redisplayed eventually.
+ ;; Despite its name, we treat jit-lock-defer-multiline here
+ ;; rather than in jit-lock-defer since it has to do with multiple
+ ;; lines, i.e. with context.
+ (when (get-text-property jit-lock-context-unfontify-pos
+ 'jit-lock-defer-multiline)
+ (setq jit-lock-context-unfontify-pos
+ (or (previous-single-property-change
+ jit-lock-context-unfontify-pos
+ 'jit-lock-defer-multiline)
+ (point-min))))
+ (with-buffer-prepared-for-jit-lock
+ ;; Force contextual refontification.
+ (remove-text-properties
+ jit-lock-context-unfontify-pos (point-max)
+ '(fontified nil jit-lock-defer-multiline nil)))
+ (setq jit-lock-context-unfontify-pos (point-max)))))))))
(defun jit-lock-after-change (start end old-len)
"Mark the rest of the buffer as not fontified after a change.
This function ensures that lines following the change will be refontified
in case the syntax of those lines has changed. Refontification
will take place when text is fontified stealthily."
- (when jit-lock-mode
- (save-excursion
- (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))
- ;; Mark the change for deferred contextual refontification.
- (when jit-lock-first-unfontify-pos
- (setq jit-lock-first-unfontify-pos
- (min jit-lock-first-unfontify-pos start))))))
-
+ (when (and jit-lock-mode (not memory-full))
+ (let ((region (font-lock-extend-region start end old-len)))
+ (save-excursion
+ (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.
+ ;;
+ ;; FIXME!!! (Alan Mackenzie, 2006-03-14): If start isn't at a BOL,
+ ;; expanding the region to BOL might mis-fontify, should the BOL not
+ ;; be at a "safe" position.
+ (setq start (if region
+ (car region)
+ (goto-char 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))))
+
+ (if region (setq end (cdr region)))
+ ;; 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))
+ ;; Mark the change for deferred contextual refontification.
+ (when 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)))))))
+
(provide 'jit-lock)
+;; arch-tag: 56b5de6e-f581-453b-bb97-49c39372ff9e
;;; jit-lock.el ends here