;;; paren.el --- highlight matching paren
-;; Copyright (C) 1993, 1996, 2001-2013 Free Software Foundation, Inc.
+;; Copyright (C) 1993, 1996, 2001-2015 Free Software Foundation, Inc.
;; Author: rms@gnu.org
-;; Maintainer: FSF
+;; Maintainer: emacs-devel@gnu.org
;; Keywords: languages, faces
;; This file is part of GNU Emacs.
:prefix "show-paren-"
:group 'paren-matching)
-;; This is the overlay used to highlight the matching paren.
-(defvar show-paren-overlay nil)
-;; This is the overlay used to highlight the closeparen right before point.
-(defvar show-paren-overlay-1 nil)
-
(defcustom show-paren-style 'parenthesis
"Style used when showing a matching paren.
Valid styles are `parenthesis' (meaning show the matching paren),
:group 'paren-showing
:version "20.3")
-(defgroup paren-showing-faces nil
- "Group for faces of Show Paren mode."
- :group 'paren-showing
- :group 'faces
- :version "22.1")
-
-(defface show-paren-match
- '((((class color) (background light))
- :background "turquoise") ; looks OK on tty (becomes cyan)
- (((class color) (background dark))
- :background "steelblue3") ; looks OK on tty (becomes blue)
- (((background dark))
- :background "grey50")
- (t
- :background "gray"))
- "Show Paren mode face used for a matching paren."
- :group 'paren-showing-faces)
(define-obsolete-face-alias 'show-paren-match-face 'show-paren-match "22.1")
-(defface show-paren-mismatch
- '((((class color)) (:foreground "white" :background "purple"))
- (t (:inverse-video t)))
- "Show Paren mode face used for a mismatching paren."
- :group 'paren-showing-faces)
(define-obsolete-face-alias 'show-paren-mismatch-face
'show-paren-mismatch "22.1")
(defvar show-paren-highlight-openparen t
"Non-nil turns on openparen highlighting when matching forward.")
-(defvar show-paren-idle-timer nil)
+(defvar show-paren--idle-timer nil)
+(defvar show-paren--overlay
+ (let ((ol (make-overlay (point) (point) nil t))) (delete-overlay ol) ol)
+ "Overlay used to highlight the matching paren.")
+(defvar show-paren--overlay-1
+ (let ((ol (make-overlay (point) (point) nil t))) (delete-overlay ol) ol)
+ "Overlay used to highlight the paren at point.")
+
;;;###autoload
(define-minor-mode show-paren-mode
matching parenthesis is highlighted in `show-paren-style' after
`show-paren-delay' seconds of Emacs idle time."
:global t :group 'paren-showing
- ;; Enable or disable the mechanism.
- ;; First get rid of the old idle timer.
- (if show-paren-idle-timer
- (cancel-timer show-paren-idle-timer))
- (setq show-paren-idle-timer nil)
- ;; If show-paren-mode is enabled in some buffer now,
- ;; set up a new timer.
- (when (memq t (mapcar (lambda (buffer)
- (with-current-buffer buffer
- show-paren-mode))
- (buffer-list)))
- (setq show-paren-idle-timer (run-with-idle-timer
- show-paren-delay t
- 'show-paren-function)))
- (unless show-paren-mode
- (and show-paren-overlay
- (eq (overlay-buffer show-paren-overlay) (current-buffer))
- (delete-overlay show-paren-overlay))
- (and show-paren-overlay-1
- (eq (overlay-buffer show-paren-overlay-1) (current-buffer))
- (delete-overlay show-paren-overlay-1))))
+ ;; Enable or disable the mechanism.
+ ;; First get rid of the old idle timer.
+ (when show-paren--idle-timer
+ (cancel-timer show-paren--idle-timer)
+ (setq show-paren--idle-timer nil))
+ (setq show-paren--idle-timer (run-with-idle-timer
+ show-paren-delay t
+ #'show-paren-function))
+ (unless show-paren-mode
+ (delete-overlay show-paren--overlay)
+ (delete-overlay show-paren--overlay-1)))
+
+(defvar show-paren-data-function #'show-paren--default
+ "Function to find the opener/closer at point and its match.
+The function is called with no argument and should return either nil
+if there's no opener/closer at point, or a list of the form
+\(HERE-BEG HERE-END THERE-BEG THERE-END MISMATCH)
+Where HERE-BEG..HERE-END is expected to be around point.")
+
+(defun show-paren--default ()
+ (let* ((oldpos (point))
+ (dir (cond ((eq (syntax-class (syntax-after (1- (point)))) 5) -1)
+ ((eq (syntax-class (syntax-after (point))) 4) 1)))
+ (unescaped
+ (when dir
+ ;; Verify an even number of quoting characters precede the paren.
+ ;; Follow the same logic as in `blink-matching-open'.
+ (= (if (= dir -1) 1 0)
+ (logand 1 (- (point)
+ (save-excursion
+ (if (= dir -1) (forward-char -1))
+ (skip-syntax-backward "/\\")
+ (point)))))))
+ (here-beg (if (eq dir 1) (point) (1- (point))))
+ (here-end (if (eq dir 1) (1+ (point)) (point)))
+ pos mismatch)
+ ;;
+ ;; Find the other end of the sexp.
+ (when unescaped
+ (save-excursion
+ (save-restriction
+ ;; Determine the range within which to look for a match.
+ (when blink-matching-paren-distance
+ (narrow-to-region
+ (max (point-min) (- (point) blink-matching-paren-distance))
+ (min (point-max) (+ (point) blink-matching-paren-distance))))
+ ;; Scan across one sexp within that range.
+ ;; Errors or nil mean there is a mismatch.
+ (condition-case ()
+ (setq pos (scan-sexps (point) dir))
+ (error (setq pos t mismatch t)))
+ ;; Move back the other way and verify we get back to the
+ ;; starting point. If not, these two parens don't really match.
+ ;; Maybe the one at point is escaped and doesn't really count,
+ ;; or one is inside a comment.
+ (when (integerp pos)
+ (unless (condition-case ()
+ (eq (point) (scan-sexps pos (- dir)))
+ (error nil))
+ (setq pos nil)))
+ ;; If found a "matching" paren, see if it is the right
+ ;; kind of paren to match the one we started at.
+ (if (not (integerp pos))
+ (if mismatch (list here-beg here-end nil nil t))
+ (let ((beg (min pos oldpos)) (end (max pos oldpos)))
+ (unless (eq (syntax-class (syntax-after beg)) 8)
+ (setq mismatch
+ (not (or (eq (char-before end)
+ ;; This can give nil.
+ (cdr (syntax-after beg)))
+ (eq (char-after beg)
+ ;; This can give nil.
+ (cdr (syntax-after (1- end))))
+ ;; The cdr might hold a new paren-class
+ ;; info rather than a matching-char info,
+ ;; in which case the two CDRs should match.
+ (eq (cdr (syntax-after (1- end)))
+ (cdr (syntax-after beg)))))))
+ (list here-beg here-end
+ (if (= dir 1) (1- pos) pos)
+ (if (= dir 1) pos (1+ pos))
+ mismatch))))))))
;; Find the place to show, if there is one,
;; and show it until input arrives.
(defun show-paren-function ()
- (if show-paren-mode
- (let* ((oldpos (point))
- (dir (cond ((eq (syntax-class (syntax-after (1- (point)))) 5) -1)
- ((eq (syntax-class (syntax-after (point))) 4) 1)))
- (unescaped
- (when dir
- ;; Verify an even number of quoting characters precede the paren.
- ;; Follow the same logic as in `blink-matching-open'.
- (= (if (= dir -1) 1 0)
- (logand 1 (- (point)
- (save-excursion
- (if (= dir -1) (forward-char -1))
- (skip-syntax-backward "/\\")
- (point)))))))
- pos mismatch face)
- ;;
- ;; Find the other end of the sexp.
- (when unescaped
- (save-excursion
- (save-restriction
- ;; Determine the range within which to look for a match.
- (when blink-matching-paren-distance
- (narrow-to-region
- (max (point-min) (- (point) blink-matching-paren-distance))
- (min (point-max) (+ (point) blink-matching-paren-distance))))
- ;; Scan across one sexp within that range.
- ;; Errors or nil mean there is a mismatch.
- (condition-case ()
- (setq pos (scan-sexps (point) dir))
- (error (setq pos t mismatch t)))
- ;; Move back the other way and verify we get back to the
- ;; starting point. If not, these two parens don't really match.
- ;; Maybe the one at point is escaped and doesn't really count.
- (when (integerp pos)
- (unless (condition-case ()
- (eq (point) (scan-sexps pos (- dir)))
- (error nil))
- (setq pos nil)))
- ;; If found a "matching" paren, see if it is the right
- ;; kind of paren to match the one we started at.
- (when (integerp pos)
- (let ((beg (min pos oldpos)) (end (max pos oldpos)))
- (unless (eq (syntax-class (syntax-after beg)) 8)
- (setq mismatch
- (not (or (eq (char-before end)
- ;; This can give nil.
- (cdr (syntax-after beg)))
- (eq (char-after beg)
- ;; This can give nil.
- (cdr (syntax-after (1- end))))
- ;; The cdr might hold a new paren-class
- ;; info rather than a matching-char info,
- ;; in which case the two CDRs should match.
- (eq (cdr (syntax-after (1- end)))
- (cdr (syntax-after beg))))))))))))
- ;;
- ;; Highlight the other end of the sexp, or unhighlight if none.
- (if (not pos)
- (progn
- ;; If not at a paren that has a match,
- ;; turn off any previous paren highlighting.
- (and show-paren-overlay (overlay-buffer show-paren-overlay)
- (delete-overlay show-paren-overlay))
- (and show-paren-overlay-1 (overlay-buffer show-paren-overlay-1)
- (delete-overlay show-paren-overlay-1)))
- ;;
- ;; Use the correct face.
- (if mismatch
- (progn
- (if show-paren-ring-bell-on-mismatch
- (beep))
- (setq face 'show-paren-mismatch))
- (setq face 'show-paren-match))
- ;;
- ;; If matching backwards, highlight the closeparen
- ;; before point as well as its matching open.
- ;; If matching forward, and the openparen is unbalanced,
- ;; highlight the paren at point to indicate misbalance.
- ;; Otherwise, turn off any such highlighting.
- (if (and (not show-paren-highlight-openparen) (= dir 1) (integerp pos))
- (when (and show-paren-overlay-1
- (overlay-buffer show-paren-overlay-1))
- (delete-overlay show-paren-overlay-1))
- (let ((from (if (= dir 1)
- (point)
- (- (point) 1)))
- (to (if (= dir 1)
- (+ (point) 1)
- (point))))
- (if show-paren-overlay-1
- (move-overlay show-paren-overlay-1 from to (current-buffer))
- (setq show-paren-overlay-1 (make-overlay from to nil t)))
- ;; Always set the overlay face, since it varies.
- (overlay-put show-paren-overlay-1 'priority show-paren-priority)
- (overlay-put show-paren-overlay-1 'face face)))
- ;;
- ;; Turn on highlighting for the matching paren, if found.
- ;; If it's an unmatched paren, turn off any such highlighting.
- (if (not (integerp pos))
- (when show-paren-overlay (delete-overlay show-paren-overlay))
- (let ((to (if (or (eq show-paren-style 'expression)
- (and (eq show-paren-style 'mixed)
- (not (pos-visible-in-window-p pos))))
- (point)
- pos))
- (from (if (or (eq show-paren-style 'expression)
- (and (eq show-paren-style 'mixed)
- (not (pos-visible-in-window-p pos))))
- pos
- (save-excursion
- (goto-char pos)
- (- (point) dir)))))
- (if show-paren-overlay
- (move-overlay show-paren-overlay from to (current-buffer))
- (setq show-paren-overlay (make-overlay from to nil t))))
- ;; Always set the overlay face, since it varies.
- (overlay-put show-paren-overlay 'priority show-paren-priority)
- (overlay-put show-paren-overlay 'face face))))
- ;; show-paren-mode is nil in this buffer.
- (and show-paren-overlay
- (delete-overlay show-paren-overlay))
- (and show-paren-overlay-1
- (delete-overlay show-paren-overlay-1))))
+ (let ((data (and show-paren-mode (funcall show-paren-data-function))))
+ (if (not data)
+ (progn
+ ;; If show-paren-mode is nil in this buffer or if not at a paren that
+ ;; has a match, turn off any previous paren highlighting.
+ (delete-overlay show-paren--overlay)
+ (delete-overlay show-paren--overlay-1))
+
+ ;; Found something to highlight.
+ (let* ((here-beg (nth 0 data))
+ (here-end (nth 1 data))
+ (there-beg (nth 2 data))
+ (there-end (nth 3 data))
+ (mismatch (nth 4 data))
+ (face
+ (if mismatch
+ (progn
+ (if show-paren-ring-bell-on-mismatch
+ (beep))
+ 'show-paren-mismatch)
+ 'show-paren-match)))
+ ;;
+ ;; If matching backwards, highlight the closeparen
+ ;; before point as well as its matching open.
+ ;; If matching forward, and the openparen is unbalanced,
+ ;; highlight the paren at point to indicate misbalance.
+ ;; Otherwise, turn off any such highlighting.
+ (if (or (not here-beg)
+ (and (not show-paren-highlight-openparen)
+ (> here-end (point))
+ (integerp there-beg)))
+ (delete-overlay show-paren--overlay-1)
+ (move-overlay show-paren--overlay-1
+ here-beg here-end (current-buffer))
+ ;; Always set the overlay face, since it varies.
+ (overlay-put show-paren--overlay-1 'priority show-paren-priority)
+ (overlay-put show-paren--overlay-1 'face face))
+ ;;
+ ;; Turn on highlighting for the matching paren, if found.
+ ;; If it's an unmatched paren, turn off any such highlighting.
+ (if (not there-beg)
+ (delete-overlay show-paren--overlay)
+ (if (or (eq show-paren-style 'expression)
+ (and (eq show-paren-style 'mixed)
+ (let ((closest (if (< there-beg here-beg)
+ (1- there-end) (1+ there-beg))))
+ (not (pos-visible-in-window-p closest)))))
+ (move-overlay show-paren--overlay
+ (point)
+ (if (< there-beg here-beg) there-beg there-end)
+ (current-buffer))
+ (move-overlay show-paren--overlay
+ there-beg there-end (current-buffer)))
+ ;; Always set the overlay face, since it varies.
+ (overlay-put show-paren--overlay 'priority show-paren-priority)
+ (overlay-put show-paren--overlay 'face face))))))
(provide 'paren)