Commit | Line | Data |
---|---|---|
f62be99b CW |
1 | ;;; font-core.el --- Core interface to font-lock |
2 | ||
ba318903 | 3 | ;; Copyright (C) 1992-2014 Free Software Foundation, Inc. |
f62be99b | 4 | |
34dc21db | 5 | ;; Maintainer: emacs-devel@gnu.org |
f62be99b | 6 | ;; Keywords: languages, faces |
bd78fa1d | 7 | ;; Package: emacs |
f62be99b CW |
8 | |
9 | ;; This file is part of GNU Emacs. | |
10 | ||
eb3fa2cf | 11 | ;; GNU Emacs is free software: you can redistribute it and/or modify |
f62be99b | 12 | ;; it under the terms of the GNU General Public License as published by |
eb3fa2cf GM |
13 | ;; the Free Software Foundation, either version 3 of the License, or |
14 | ;; (at your option) any later version. | |
f62be99b CW |
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 | |
eb3fa2cf | 22 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. |
f62be99b CW |
23 | |
24 | ;;; Code: | |
25 | ||
26 | ;; This variable is used by mode packages that support Font Lock mode by | |
27 | ;; defining their own keywords to use for `font-lock-keywords'. (The mode | |
28 | ;; command should make it buffer-local and set it to provide the set up.) | |
29 | (defvar font-lock-defaults nil | |
30 | "Defaults for Font Lock mode specified by the major mode. | |
31 | Defaults should be of the form: | |
32 | ||
77f5a70d | 33 | (KEYWORDS [KEYWORDS-ONLY [CASE-FOLD [SYNTAX-ALIST [SYNTAX-BEGIN ...]]]]) |
f62be99b | 34 | |
5ff602de GM |
35 | KEYWORDS may be a symbol (a variable or function whose value is the keywords |
36 | to use for fontification) or a list of symbols (specifying different levels | |
37 | of fontification). | |
38 | ||
39 | If KEYWORDS-ONLY is non-nil, syntactic fontification (strings and | |
40 | comments) is not performed. | |
41 | ||
f62be99b | 42 | If CASE-FOLD is non-nil, the case of the keywords is ignored when fontifying. |
5ff602de | 43 | |
f62be99b CW |
44 | If SYNTAX-ALIST is non-nil, it should be a list of cons pairs of the form |
45 | \(CHAR-OR-STRING . STRING) used to set the local Font Lock syntax table, for | |
46 | keyword and syntactic fontification (see `modify-syntax-entry'). | |
47 | ||
48 | If SYNTAX-BEGIN is non-nil, it should be a function with no args used to move | |
49 | backwards outside any enclosing syntactic block, for syntactic fontification. | |
50 | Typical values are `beginning-of-line' (i.e., the start of the line is known to | |
51 | be outside a syntactic block), or `beginning-of-defun' for programming modes or | |
52 | `backward-paragraph' for textual modes (i.e., the mode-dependent function is | |
53 | known to move outside a syntactic block). If nil, the beginning of the buffer | |
54 | is used as a position outside of a syntactic block, in the worst case. | |
55 | ||
5ff602de GM |
56 | \(See also Info node `(elisp)Font Lock Basics'.) |
57 | ||
f62be99b CW |
58 | These item elements are used by Font Lock mode to set the variables |
59 | `font-lock-keywords', `font-lock-keywords-only', | |
60 | `font-lock-keywords-case-fold-search', `font-lock-syntax-table' and | |
61 | `font-lock-beginning-of-syntax-function', respectively. | |
62 | ||
63 | Further item elements are alists of the form (VARIABLE . VALUE) and are in no | |
64 | particular order. Each VARIABLE is made buffer-local before set to VALUE. | |
65 | ||
66 | Currently, appropriate variables include `font-lock-mark-block-function'. | |
67 | If this is non-nil, it should be a function with no args used to mark any | |
68 | enclosing block of text, for fontification via \\[font-lock-fontify-block]. | |
69 | Typical values are `mark-defun' for programming modes or `mark-paragraph' for | |
70 | textual modes (i.e., the mode-dependent function is known to put point and mark | |
71 | around a text block relevant to that mode). | |
72 | ||
73 | Other variables include that for syntactic keyword fontification, | |
77f5a70d LK |
74 | `font-lock-syntactic-keywords' and those for buffer-specialized fontification |
75 | functions, `font-lock-fontify-buffer-function', | |
76 | `font-lock-unfontify-buffer-function', `font-lock-fontify-region-function', | |
77 | `font-lock-unfontify-region-function', and `font-lock-inhibit-thing-lock'.") | |
ac549fa5 | 78 | ;;;###autoload |
6dc3311d | 79 | (put 'font-lock-defaults 'risky-local-variable t) |
f62be99b CW |
80 | (make-variable-buffer-local 'font-lock-defaults) |
81 | ||
7c4ef9b3 CW |
82 | (defvar font-lock-function 'font-lock-default-function |
83 | "A function which is called when `font-lock-mode' is toggled. | |
84 | It will be passed one argument, which is the current value of | |
85 | `font-lock-mode'.") | |
7c4ef9b3 | 86 | |
642b63e8 | 87 | ;; The mode for which font-lock was initialized, or nil if none. |
36901266 | 88 | (defvar font-lock-major-mode) |
06e21633 | 89 | |
f62be99b | 90 | (define-minor-mode font-lock-mode |
06e21633 CY |
91 | "Toggle syntax highlighting in this buffer (Font Lock mode). |
92 | With a prefix argument ARG, enable Font Lock mode if ARG is | |
93 | positive, and disable it otherwise. If called from Lisp, enable | |
94 | the mode if ARG is omitted or nil. | |
f62be99b CW |
95 | |
96 | When Font Lock mode is enabled, text is fontified as you type it: | |
97 | ||
98 | - Comments are displayed in `font-lock-comment-face'; | |
99 | - Strings are displayed in `font-lock-string-face'; | |
100 | - Certain other expressions are displayed in other faces according to the | |
101 | value of the variable `font-lock-keywords'. | |
102 | ||
103 | To customize the faces (colors, fonts, etc.) used by Font Lock for | |
104 | fontifying different parts of buffer text, use \\[customize-face]. | |
105 | ||
106 | You can enable Font Lock mode in any major mode automatically by turning on in | |
107 | the major mode's hook. For example, put in your ~/.emacs: | |
108 | ||
109 | (add-hook 'c-mode-hook 'turn-on-font-lock) | |
110 | ||
111 | Alternatively, you can use Global Font Lock mode to automagically turn on Font | |
112 | Lock mode in buffers whose major mode supports it and whose major mode is one | |
113 | of `font-lock-global-modes'. For example, put in your ~/.emacs: | |
114 | ||
115 | (global-font-lock-mode t) | |
116 | ||
ea5b829c RF |
117 | Where major modes support different levels of fontification, you can use |
118 | the variable `font-lock-maximum-decoration' to specify which level you | |
119 | generally prefer. When you turn Font Lock mode on/off the buffer is | |
120 | fontified/defontified, though fontification occurs only if the buffer is | |
121 | less than `font-lock-maximum-size'. | |
f62be99b | 122 | |
f62be99b CW |
123 | To add your own highlighting for some major mode, and modify the highlighting |
124 | selected automatically via the variable `font-lock-maximum-decoration', you can | |
125 | use `font-lock-add-keywords'. | |
126 | ||
127 | To fontify a buffer, without turning on Font Lock mode and regardless of buffer | |
128 | size, you can use \\[font-lock-fontify-buffer]. | |
129 | ||
130 | To fontify a block (the function or paragraph containing point, or a number of | |
131 | lines around point), perhaps because modification on the current line caused | |
132 | syntactic change on other lines, you can use \\[font-lock-fontify-block]. | |
133 | ||
6aecca99 | 134 | You can set your own default settings for some mode, by setting a |
7c4ef9b3 CW |
135 | buffer local value for `font-lock-defaults', via its mode hook. |
136 | ||
137 | The above is the default behavior of `font-lock-mode'; you may specify | |
138 | your own function which is called when `font-lock-mode' is toggled via | |
139 | `font-lock-function'. " | |
9324f671 | 140 | nil nil nil |
487915d7 | 141 | :after-hook (font-lock-initial-fontify) |
f62be99b CW |
142 | ;; Don't turn on Font Lock mode if we don't have a display (we're running a |
143 | ;; batch job) or if the buffer is invisible (the name starts with a space). | |
5a4689d9 | 144 | (when (or noninteractive (eq (aref (buffer-name) 0) ?\s)) |
f62be99b | 145 | (setq font-lock-mode nil)) |
8e97108f RS |
146 | (funcall font-lock-function font-lock-mode) |
147 | ;; Arrange to unfontify this buffer if we change major mode later. | |
148 | (if font-lock-mode | |
2dc20ca8 | 149 | (add-hook 'change-major-mode-hook 'font-lock-change-mode nil t) |
36901266 | 150 | (remove-hook 'change-major-mode-hook 'font-lock-change-mode t))) |
2dc20ca8 RS |
151 | |
152 | ;; Get rid of fontification for the old major mode. | |
153 | ;; We do this when changing major modes. | |
154 | (defun font-lock-change-mode () | |
40e2bbe9 SM |
155 | (font-lock-mode -1)) |
156 | ||
67c9f58d RS |
157 | (defun font-lock-defontify () |
158 | "Clear out all `font-lock-face' properties in current buffer. | |
e350babd | 159 | A major mode that uses `font-lock-face' properties might want to put |
67c9f58d RS |
160 | this function onto `change-major-mode-hook'." |
161 | (let ((modp (buffer-modified-p)) | |
162 | (inhibit-read-only t)) | |
163 | (save-restriction | |
164 | (widen) | |
165 | (remove-list-of-text-properties (point-min) (point-max) | |
166 | '(font-lock-face))) | |
bb125ff0 | 167 | (restore-buffer-modified-p modp))) |
67c9f58d | 168 | |
642b63e8 | 169 | (defvar font-lock-set-defaults) |
40e2bbe9 | 170 | (defun font-lock-default-function (mode) |
f62be99b | 171 | ;; Turn on Font Lock mode. |
40e2bbe9 | 172 | (when mode |
1b6adddb CW |
173 | (set (make-local-variable 'char-property-alias-alist) |
174 | (copy-tree char-property-alias-alist)) | |
175 | ;; Add `font-lock-face' as an alias for the `face' property. | |
176 | (let ((elt (assq 'face char-property-alias-alist))) | |
177 | (if elt | |
178 | (unless (memq 'font-lock-face (cdr elt)) | |
179 | (setcdr elt (nconc (cdr elt) (list 'font-lock-face)))) | |
e350babd | 180 | (push (list 'face 'font-lock-face) char-property-alias-alist)))) |
f62be99b | 181 | ;; Turn off Font Lock mode. |
40e2bbe9 | 182 | (unless mode |
1b6adddb CW |
183 | ;; Remove `font-lock-face' as an alias for the `face' property. |
184 | (set (make-local-variable 'char-property-alias-alist) | |
185 | (copy-tree char-property-alias-alist)) | |
186 | (let ((elt (assq 'face char-property-alias-alist))) | |
187 | (when elt | |
188 | (setcdr elt (remq 'font-lock-face (cdr elt))) | |
189 | (when (null (cdr elt)) | |
e350babd SM |
190 | (setq char-property-alias-alist |
191 | (delq elt char-property-alias-alist)))))) | |
192 | ||
193 | ;; Only do hard work if the mode has specified stuff in | |
194 | ;; `font-lock-defaults'. | |
c98c6276 | 195 | (when (font-lock-specified-p mode) |
e350babd | 196 | (font-lock-mode-internal mode))) |
71296446 | 197 | |
f62be99b CW |
198 | (defun turn-on-font-lock () |
199 | "Turn on Font Lock mode (only if the terminal can display it)." | |
200 | (unless font-lock-mode | |
201 | (font-lock-mode))) | |
202 | ||
f62be99b CW |
203 | ;;; Global Font Lock mode. |
204 | ||
205 | ;; A few people have hassled in the past for a way to make it easier to turn on | |
206 | ;; Font Lock mode, without the user needing to know for which modes s/he has to | |
207 | ;; turn it on, perhaps the same way hilit19.el/hl319.el does. I've always | |
e1dbe924 | 208 | ;; balked at that way, as I see it as just re-molding the same problem in |
f62be99b CW |
209 | ;; another form. That is; some person would still have to keep track of which |
210 | ;; modes (which may not even be distributed with Emacs) support Font Lock mode. | |
211 | ;; The list would always be out of date. And that person might have to be me. | |
212 | ||
213 | ;; Implementation. | |
214 | ;; | |
215 | ;; In a previous discussion the following hack came to mind. It is a gross | |
216 | ;; hack, but it generally works. We use the convention that major modes start | |
217 | ;; by calling the function `kill-all-local-variables', which in turn runs | |
218 | ;; functions on the hook variable `change-major-mode-hook'. We attach our | |
219 | ;; function `font-lock-change-major-mode' to that hook. Of course, when this | |
220 | ;; hook is run, the major mode is in the process of being changed and we do not | |
221 | ;; know what the final major mode will be. So, `font-lock-change-major-mode' | |
222 | ;; only (a) notes the name of the current buffer, and (b) adds our function | |
35a46c5c | 223 | ;; `turn-on-font-lock-if-desired' to the hook variables |
21178fee LT |
224 | ;; `after-change-major-mode-hook' and `post-command-hook' (for modes |
225 | ;; that do not yet run `after-change-major-mode-hook'). By the time | |
f62be99b CW |
226 | ;; the functions on the first of these hooks to be run are run, the new major |
227 | ;; mode is assumed to be in place. This way we get a Font Lock function run | |
228 | ;; when a major mode is turned on, without knowing major modes or their hooks. | |
229 | ;; | |
21178fee LT |
230 | ;; Naturally this requires that major modes run `kill-all-local-variables' |
231 | ;; and `after-change-major-mode-hook', as they are supposed to. For modes | |
232 | ;; that do not run `after-change-major-mode-hook' yet, `post-command-hook' | |
233 | ;; takes care of things if the mode is set directly or indirectly by | |
234 | ;; an interactive command; however, problems can occur if the mode is | |
235 | ;; set by a timer or process: in that case, proper handling of Font Lock mode | |
236 | ;; may be delayed until the next interactive command. | |
f62be99b CW |
237 | |
238 | ;; User interface. | |
239 | ;; | |
240 | ;; Although Global Font Lock mode is a pseudo-mode, I think that the user | |
241 | ;; interface should conform to the usual Emacs convention for modes, i.e., a | |
242 | ;; command to toggle the feature (`global-font-lock-mode') with a variable for | |
fffa137c | 243 | ;; finer control of the mode's behavior (`font-lock-global-modes'). |
f62be99b CW |
244 | ;; |
245 | ;; The feature should not be enabled by loading font-lock.el, since other | |
246 | ;; mechanisms for turning on Font Lock mode, such as M-x font-lock-mode RET or | |
247 | ;; (add-hook 'c-mode-hook 'turn-on-font-lock), would cause Font Lock mode to be | |
248 | ;; turned on everywhere. That would not be intuitive or informative because | |
249 | ;; loading a file tells you nothing about the feature or how to control it. It | |
250 | ;; would also be contrary to the Principle of Least Surprise. sm. | |
251 | ||
252 | (defcustom font-lock-global-modes t | |
9201cc28 | 253 | "Modes for which Font Lock mode is automagically turned on. |
f62be99b CW |
254 | Global Font Lock mode is controlled by the command `global-font-lock-mode'. |
255 | If nil, means no modes have Font Lock mode automatically turned on. | |
256 | If t, all modes that support Font Lock mode have it automatically turned on. | |
257 | If a list, it should be a list of `major-mode' symbol names for which Font Lock | |
258 | mode should be automatically turned on. The sense of the list is negated if it | |
259 | begins with `not'. For example: | |
260 | (c-mode c++-mode) | |
261 | means that Font Lock mode is turned on for buffers in C and C++ modes only." | |
262 | :type '(choice (const :tag "none" nil) | |
263 | (const :tag "all" t) | |
264 | (set :menu-tag "mode specific" :tag "modes" | |
265 | :value (not) | |
266 | (const :tag "Except" not) | |
267 | (repeat :inline t (symbol :tag "mode")))) | |
268 | :group 'font-lock) | |
269 | ||
35a46c5c RS |
270 | (defun turn-on-font-lock-if-desired () |
271 | (when (cond ((eq font-lock-global-modes t) | |
272 | t) | |
273 | ((eq (car-safe font-lock-global-modes) 'not) | |
274 | (not (memq major-mode (cdr font-lock-global-modes)))) | |
347437a5 | 275 | (t (memq major-mode font-lock-global-modes))) |
f62be99b CW |
276 | (let (inhibit-quit) |
277 | (turn-on-font-lock)))) | |
278 | ||
44cba17e | 279 | (define-globalized-minor-mode global-font-lock-mode |
35a46c5c | 280 | font-lock-mode turn-on-font-lock-if-desired |
adba8116 SM |
281 | ;; What was this :extra-args thingy for? --Stef |
282 | ;; :extra-args (dummy) | |
283 | :initialize 'custom-initialize-delay | |
3ff522d9 JL |
284 | :init-value (not (or noninteractive emacs-basic-display)) |
285 | :group 'font-lock | |
286 | :version "22.1") | |
f62be99b CW |
287 | |
288 | ;;; End of Global Font Lock mode. | |
289 | ||
290 | (provide 'font-core) | |
291 | ||
292 | ;;; font-core.el ends here |