1 ;;; paren.el --- highlight matching paren.
2 ;; Copyright (C) 1993 Free Software Foundation, Inc.
4 ;; Author: rms@gnu.ai.mit.edu
6 ;; Keywords: languages, faces
8 ;; This file is part of GNU Emacs.
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)
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.
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
22 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
26 ;; Load this and it will display highlighting on whatever
27 ;; paren matches the one before or after point.
31 ;; This is the overlay used to highlight the matching paren.
32 (defvar show-paren-overlay nil
)
33 ;; This is the overlay used to highlight the closeparen
34 ;; right before point.
35 (defvar show-paren-overlay-1 nil
)
37 (defvar show-paren-mismatch-face nil
)
39 (defvar show-paren-face
'region
40 "*Name of face to use for showing the matching paren.")
42 ;; Find the place to show, if there is one,
43 ;; and show it until input arrives.
44 (defun show-paren-command-hook ()
45 ;; Do nothing if no window system to display results with.
46 ;; Do nothing if executing keyboard macro.
47 ;; Do nothing if input is pending.
49 (let (pos dir mismatch
(oldpos (point))
50 (face show-paren-face
))
51 (cond ((eq (char-syntax (preceding-char)) ?\
))
53 ((eq (char-syntax (following-char)) ?\
()
58 ;; Determine the range within which to look for a match.
59 (if blink-matching-paren-distance
60 (narrow-to-region (max (point-min)
61 (- (point) blink-matching-paren-distance
))
63 (+ (point) blink-matching-paren-distance
))))
64 ;; Scan across one sexp within that range.
66 (setq pos
(scan-sexps (point) dir
))
68 ;; See if the "matching" paren is the right kind of paren
69 ;; to match the one we started at.
71 (let ((beg (min pos oldpos
)) (end (max pos oldpos
)))
72 (and (/= (char-syntax (char-after beg
)) ?\$
)
74 (not (eq (char-after (1- end
))
76 (matching-paren (char-after beg
))))))))
77 ;; If they don't properly match, use a different face,
78 ;; or print a message.
81 (and (null show-paren-mismatch-face
)
84 (add-to-list 'facemenu-unlisted-faces
86 (make-face 'paren-mismatch
)
87 (or (face-nontrivial-p 'paren-mismatch t
)
89 (set-face-background 'paren-mismatch
91 (set-face-foreground 'paren-mismatch
93 (setq show-paren-mismatch-face
'paren-mismatch
)))
94 (if show-paren-mismatch-face
95 (setq face show-paren-mismatch-face
)
96 (message "Paren mismatch"))))
100 ;; If matching backwards, highlight the closeparen
101 ;; before point as well as its matching open.
103 (if show-paren-overlay-1
104 (move-overlay show-paren-overlay-1
105 (+ (point) dir
) (point)
107 (setq show-paren-overlay-1
108 (make-overlay (- pos dir
) pos
)))
109 ;; Always set the overlay face, since it varies.
110 (overlay-put show-paren-overlay-1
'face face
))
111 ;; Otherwise, turn off any such highlighting.
112 (and show-paren-overlay-1
113 (overlay-buffer show-paren-overlay-1
)
114 (delete-overlay show-paren-overlay-1
)))
115 ;; Turn on highlighting for the matching paren.
116 (if show-paren-overlay
117 (move-overlay show-paren-overlay
(- pos dir
) pos
119 (setq show-paren-overlay
120 (make-overlay (- pos dir
) pos
)))
121 ;; Always set the overlay face, since it varies.
122 (overlay-put show-paren-overlay
'face face
))
124 ;; If not at a paren that has a match,
125 ;; turn off any previous paren highlighting.
126 (and show-paren-overlay
(overlay-buffer show-paren-overlay
)
127 (delete-overlay show-paren-overlay
))
128 (and show-paren-overlay-1
(overlay-buffer show-paren-overlay-1
)
129 (delete-overlay show-paren-overlay-1
)))))))
133 (setq blink-paren-function nil
)
134 (add-hook 'post-command-idle-hook
'show-paren-command-hook
)))
135 ;;; This is in case paren.el is preloaded.
136 (add-hook 'window-setup-hook
140 (setq blink-paren-function nil
)
141 (add-hook 'post-command-idle-hook
142 'show-paren-command-hook
))))))
145 ;;; paren.el ends here