mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-12-14 09:39:42 +00:00
573 lines
22 KiB
EmacsLisp
573 lines
22 KiB
EmacsLisp
;;; jit-lock.el --- just-in-time fontification
|
||
|
||
;; Copyright (C) 1998, 2000, 2001, 2004 Free Software Foundation, Inc.
|
||
|
||
;; Author: Gerd Moellmann <gerd@gnu.org>
|
||
;; Keywords: faces files
|
||
|
||
;; This file is part of GNU Emacs.
|
||
|
||
;; GNU Emacs is free software; you can redistribute it and/or modify
|
||
;; it under the terms of the GNU General Public License as published by
|
||
;; the Free Software Foundation; either version 2, or (at your option)
|
||
;; any later version.
|
||
|
||
;; GNU Emacs is distributed in the hope that it will be useful,
|
||
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
;; GNU General Public License for more details.
|
||
|
||
;; 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.
|
||
|
||
;;; Commentary:
|
||
|
||
;; Just-in-time fontification, triggered by C redisplay code.
|
||
|
||
;;; Code:
|
||
|
||
|
||
(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)
|
||
(inhibit-point-motion-hooks t)
|
||
(inhibit-modification-hooks t)
|
||
deactivate-mark
|
||
buffer-file-name
|
||
buffer-file-truename)
|
||
,@body))))
|
||
|
||
|
||
|
||
;;; 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."
|
||
:type 'integer
|
||
:group 'jit-lock)
|
||
|
||
|
||
(defcustom jit-lock-stealth-time 3
|
||
"*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.
|
||
|
||
The value of this variable is used when JIT Lock mode is turned on."
|
||
:type '(choice (const :tag "never" nil)
|
||
(number :tag "seconds"))
|
||
:group 'jit-lock)
|
||
|
||
|
||
(defcustom jit-lock-stealth-nice 0.125
|
||
"*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.
|
||
If nil, means stealth fontification is never paused.
|
||
To reduce machine load during stealth fontification, at the cost of stealth
|
||
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"))
|
||
:group 'jit-lock)
|
||
|
||
|
||
(defcustom jit-lock-stealth-load
|
||
(if (condition-case nil (load-average) (error)) 200)
|
||
"*Load in percentage above which stealth fontification is suspended.
|
||
Stealth fontification pauses when the system short-term load average (as
|
||
returned by the function `load-average' if supported) goes above this level,
|
||
thus reducing the demand that stealth fontification makes on the system.
|
||
If nil, means stealth fontification is never suspended.
|
||
To reduce machine load during stealth fontification, at the cost of stealth
|
||
taking longer to fontify, you could reduce the value of this variable.
|
||
See also `jit-lock-stealth-nice'."
|
||
:type (if (condition-case nil (load-average) (error))
|
||
'(choice (const :tag "never" nil)
|
||
(integer :tag "load"))
|
||
'(const :format "%t: unsupported\n" nil))
|
||
:group 'jit-lock)
|
||
|
||
|
||
(defcustom jit-lock-stealth-verbose nil
|
||
"*If non-nil, means stealth fontification should show status messages."
|
||
:type 'boolean
|
||
:group 'jit-lock)
|
||
|
||
|
||
(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 fontification occurs on those lines modified and all
|
||
subsequent lines. This means those subsequent lines are refontified to reflect
|
||
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.
|
||
|
||
The value of this variable is used when JIT Lock mode is turned on."
|
||
:type '(choice (const :tag "never" nil)
|
||
(const :tag "always" t)
|
||
(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"))
|
||
|
||
(defcustom jit-lock-defer-time nil ;; 0.25
|
||
"Idle time after which deferred fontification should take place.
|
||
If nil, fontification is not deferred."
|
||
:group 'jit-lock
|
||
:type '(choice (const :tag "never" nil)
|
||
(number :tag "seconds")))
|
||
|
||
;;; Variables that are not customizable.
|
||
|
||
(defvar jit-lock-mode nil
|
||
"Non-nil means Just-in-time Lock mode is active.")
|
||
(make-variable-buffer-local 'jit-lock-mode)
|
||
|
||
(defvar jit-lock-functions nil
|
||
"Functions to do the actual fontification.
|
||
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-context-unfontify-pos nil
|
||
"Consider text after this position as contextually unfontified.
|
||
If nil, contextual fontification is disabled.")
|
||
(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-defer-buffers nil
|
||
"List of buffers with pending deferred fontification.")
|
||
|
||
;;; JIT lock mode
|
||
|
||
(defun jit-lock-mode (arg)
|
||
"Toggle Just-in-time Lock mode.
|
||
Turn Just-in-time Lock mode on if and only if ARG is non-nil.
|
||
Enable it automatically by customizing group `font-lock'.
|
||
|
||
When Just-in-time Lock mode is enabled, fontification is different in the
|
||
following ways:
|
||
|
||
- Demand-driven buffer fontification triggered by Emacs C code.
|
||
This means initial fontification of the whole buffer does not occur.
|
||
Instead, fontification occurs when necessary, such as when scrolling
|
||
through the buffer would otherwise reveal unfontified areas. This is
|
||
useful if buffer fontification is too slow for large buffers.
|
||
|
||
- Stealthy buffer fontification if `jit-lock-stealth-time' is non-nil.
|
||
This means remaining unfontified areas of buffers are fontified if Emacs has
|
||
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-contextually' is
|
||
non-nil. This means fontification updates the buffer corresponding to
|
||
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
|
||
strings or comments span lines.
|
||
|
||
Stealth fontification only occurs while the system remains unloaded.
|
||
If the system load rises above `jit-lock-stealth-load' percent, stealth
|
||
fontification is suspended. Stealth fontification intensity is controlled via
|
||
the variable `jit-lock-stealth-nice'."
|
||
(setq jit-lock-mode arg)
|
||
(cond (;; Turn Just-in-time Lock mode on.
|
||
jit-lock-mode
|
||
|
||
;; Mark the buffer for refontification.
|
||
(jit-lock-refontify)
|
||
|
||
;; Install an idle timer for stealth fontification.
|
||
(when (and jit-lock-stealth-time (null jit-lock-stealth-timer))
|
||
(setq jit-lock-stealth-timer
|
||
(run-with-idle-timer jit-lock-stealth-time t
|
||
'jit-lock-stealth-fontify)))
|
||
|
||
;; Init deferred fontification timer.
|
||
(when (and jit-lock-defer-time (null jit-lock-defer-timer))
|
||
(setq jit-lock-defer-timer
|
||
(run-with-idle-timer jit-lock-defer-time t
|
||
'jit-lock-deferred-fontify)))
|
||
|
||
;; 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)
|
||
(add-hook 'fontification-functions 'jit-lock-function))
|
||
|
||
;; Turn Just-in-time Lock mode off.
|
||
(t
|
||
;; Cancel our idle timers.
|
||
(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))
|
||
(with-current-buffer buf
|
||
(when jit-lock-mode (throw 'found t)))))))
|
||
(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 hooks.
|
||
(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-contextually)
|
||
(set (make-local-variable 'jit-lock-contextually) t))
|
||
(jit-lock-mode t))
|
||
|
||
(defun jit-lock-unregister (fun)
|
||
"Unregister FUN as a fontification function.
|
||
Only applies to the current buffer."
|
||
(remove-hook 'jit-lock-functions fun t)
|
||
(unless jit-lock-functions (jit-lock-mode nil)))
|
||
|
||
;; This function is used to prevent font-lock-fontify-buffer from
|
||
;; fontifying eagerly the whole buffer. This is important for
|
||
;; things like CWarn mode which adds/removes a few keywords and
|
||
;; does a refontify (which takes ages on large files).
|
||
(defun jit-lock-refontify (&optional beg end)
|
||
"Force refontification of the region BEG..END (default whole buffer)."
|
||
(with-buffer-prepared-for-jit-lock
|
||
(save-restriction
|
||
(widen)
|
||
(put-text-property (or beg (point-min)) (or end (point-max))
|
||
'fontified nil))))
|
||
|
||
;;; On demand fontification.
|
||
|
||
(defun jit-lock-function (start)
|
||
"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)
|
||
;; No deferral.
|
||
(jit-lock-fontify-now start (+ start jit-lock-chunk-size))
|
||
;; Record the buffer for later fontification.
|
||
(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
|
||
(put-text-property start
|
||
(next-single-property-change
|
||
start 'fontified nil
|
||
(min (point-max) (+ start jit-lock-chunk-size)))
|
||
'fontified 'defer)))))
|
||
|
||
(defun jit-lock-fontify-now (&optional start end)
|
||
"Fontify current buffer from START to END.
|
||
Defaults to the whole buffer. END can be out of bounds."
|
||
(with-buffer-prepared-for-jit-lock
|
||
(save-excursion
|
||
(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)
|
||
(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))))))))
|
||
|
||
|
||
;;; Stealth fontification.
|
||
|
||
(defsubst jit-lock-stealth-chunk-start (around)
|
||
"Return the start of the next chunk to fontify around position AROUND..
|
||
Value is nil if there is nothing more to fontify."
|
||
(if (zerop (buffer-size))
|
||
nil
|
||
(save-restriction
|
||
(widen)
|
||
(let* ((next (text-property-not-all around (point-max) 'fontified t))
|
||
(prev (previous-single-property-change around 'fontified))
|
||
(prop (get-text-property (max (point-min) (1- around))
|
||
'fontified))
|
||
(start (cond
|
||
((null prev)
|
||
;; There is no property change between AROUND
|
||
;; and the start of the buffer. If PROP is
|
||
;; non-nil, everything in front of AROUND is
|
||
;; fontified, otherwise nothing is fontified.
|
||
(if (eq prop t)
|
||
nil
|
||
(max (point-min)
|
||
(- around (/ jit-lock-chunk-size 2)))))
|
||
((eq prop t)
|
||
;; PREV is the start of a region of fontified
|
||
;; text containing AROUND. Start fontifying a
|
||
;; chunk size before the end of the unfontified
|
||
;; region in front of that.
|
||
(max (or (previous-single-property-change prev 'fontified)
|
||
(point-min))
|
||
(- prev jit-lock-chunk-size)))
|
||
(t
|
||
;; PREV is the start of a region of unfontified
|
||
;; text containing AROUND. Start at PREV or
|
||
;; chunk size in front of AROUND, whichever is
|
||
;; nearer.
|
||
(max prev (- around jit-lock-chunk-size)))))
|
||
(result (cond ((null start) next)
|
||
((null next) start)
|
||
((< (- around start) (- next around)) start)
|
||
(t next))))
|
||
result))))
|
||
|
||
|
||
(defun jit-lock-stealth-fontify ()
|
||
"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
|
||
(unless (or executing-kbd-macro
|
||
(window-minibuffer-p (selected-window)))
|
||
(let ((buffers (buffer-list))
|
||
(outer-buffer (current-buffer))
|
||
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))))))))))))))
|
||
|
||
|
||
|
||
;;; Deferred fontification.
|
||
|
||
(defun jit-lock-deferred-fontify ()
|
||
"Fontify what was deferred."
|
||
(when jit-lock-defer-buffers
|
||
;; Mark the deferred regions back to `fontified = nil'
|
||
(dolist (buffer jit-lock-defer-buffers)
|
||
(when (buffer-live-p buffer)
|
||
(with-current-buffer buffer
|
||
;; (message "Jit-Defer %s" (buffer-name))
|
||
(with-buffer-prepared-for-jit-lock
|
||
(let ((pos (point-min)))
|
||
(while
|
||
(progn
|
||
(when (eq (get-text-property pos 'fontified) 'defer)
|
||
(put-text-property
|
||
pos (setq pos (next-single-property-change
|
||
pos 'fontified nil (point-max)))
|
||
'fontified nil))
|
||
(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))
|
||
;; (message "Jit-Defer Now")
|
||
(sit-for 0)
|
||
;; (message "Jit-Defer Done")
|
||
)))
|
||
|
||
|
||
(defun jit-lock-context-fontify ()
|
||
"Refresh fontification to take new context into account."
|
||
(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.
|
||
Installed on `after-change-functions'.
|
||
START and END are the start and end of the changed text. OLD-LEN
|
||
is the pre-change length.
|
||
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-context-unfontify-pos
|
||
(setq jit-lock-context-unfontify-pos
|
||
(min jit-lock-context-unfontify-pos start))))))
|
||
|
||
(provide 'jit-lock)
|
||
|
||
;;; arch-tag: 56b5de6e-f581-453b-bb97-49c39372ff9e
|
||
;;; jit-lock.el ends here
|