Commit 173f2341 authored by Simon Marshall's avatar Simon Marshall
Browse files

customise, rewrite and extend.

parent 93853f3d
......@@ -30,22 +30,18 @@
;;; Code:
(defgroup paren-showing nil
"Showing (un)matching of parens and expressions."
: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)
(defvar show-paren-mode nil)
(defvar show-paren-idle-timer nil)
(defvar show-paren-mismatch-face nil)
(defvar show-paren-delay (if (featurep 'lisp-float-type) 0.125 1)
"*Time in seconds to delay before showing the matching paren.")
(defvar show-paren-face 'region
"*Name of the face to use for showing the matching paren.")
;;;###autoload
(defun show-paren-mode (&optional arg)
"Toggle Show Paren mode.
......@@ -53,22 +49,68 @@ With prefix ARG, turn Show Paren mode on if and only if ARG is positive.
Returns the new status of Show Paren mode (non-nil means on).
When Show Paren mode is enabled, any matching parenthesis is highlighted
after `show-paren-delay' seconds of Emacs idle time."
in `show-paren-style' after `show-paren-delay' seconds of Emacs idle time."
(interactive "P")
(if window-system
(let ((on-p (if arg
(> (prefix-numeric-value arg) 0)
(not show-paren-mode))))
(setq blink-matching-paren-on-screen (not on-p))
(and show-paren-idle-timer (cancel-timer show-paren-idle-timer))
(if on-p
(setq show-paren-idle-timer (run-with-idle-timer show-paren-delay t
'show-paren-function))
(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)))
(setq show-paren-mode on-p))))
(when window-system
(let ((on-p (if arg
(> (prefix-numeric-value arg) 0)
(not show-paren-mode))))
(setq blink-matching-paren-on-screen (not on-p))
(when show-paren-idle-timer
(cancel-timer show-paren-idle-timer))
(if on-p
(setq show-paren-idle-timer (run-with-idle-timer
show-paren-delay t
'show-paren-function))
(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)))
(setq show-paren-mode on-p))))
;; Naughty hack. This variable was originally a `defvar' to keep track of
;; whether Show Paren mode was turned on or not. As a `defcustom' with
;; special `:set' and `:require' forms, we can provide custom mode control.
(defcustom show-paren-mode nil
"Toggle Show Paren mode.
When Show Paren mode is enabled, any matching parenthesis is highlighted
after `show-paren-delay' seconds of Emacs idle time.
You must modify via \\[customize] for this variable to have an effect."
:set (lambda (symbol value)
(show-paren-mode (or value 0)))
:type 'boolean
:group 'paren-showing
:require 'paren)
(defcustom show-paren-style 'parenthesis
"*Style used when showing a matching paren.
Valid styles are `parenthesis' (meaning show the matching paren),
`expression' (meaning show the entire expression enclosed by the paren) and
`mixed' (meaning show the matching paren if it is visible, and the expression
otherwise)."
:type '(choice (const parenthesis) (const expression) (const mixed))
:group 'paren-showing)
(defcustom show-paren-delay
(if (featurep 'lisp-float-type) (/ (float 1) (float 8)) 1)
"*Time in seconds to delay before showing a matching paren."
:type '(number :tag "seconds")
:group 'paren-showing)
(defface show-paren-match-face
'((((class color)) (:background "turquoise"))
(((class grayscale)) (:background "gray"))
(t (:reverse-video t)))
"Show Paren mode face used for a matching paren."
:group 'faces
:group 'paren-showing)
(defface show-paren-mismatch-face
'((((class color)) (:foreground "white" :background "purple"))
(t (:reverse-video t)))
"Show Paren mode face used for a mismatching paren."
:group 'faces
:group 'paren-showing)
;; Find the place to show, if there is one,
;; and show it until input arrives.
......@@ -76,105 +118,95 @@ after `show-paren-delay' seconds of Emacs idle time."
;; Do nothing if no window system to display results with.
;; Do nothing if executing keyboard macro.
;; Do nothing if input is pending.
(if window-system
(let (pos dir mismatch (oldpos (point))
(face show-paren-face))
(cond ((eq (char-syntax (preceding-char)) ?\))
(setq dir -1))
((eq (char-syntax (following-char)) ?\()
(setq dir 1)))
(if dir
(save-excursion
(save-restriction
;; Determine the range within which to look for a match.
(if 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)))
;; If found a "matching" paren, see if it is the right
;; kind of paren to match the one we started at.
(if (integerp pos)
(let ((beg (min pos oldpos)) (end (max pos oldpos)))
(and (/= (char-syntax (char-after beg)) ?\$)
(setq mismatch
(not (eq (char-before end)
;; This can give nil.
(matching-paren (char-after beg))))))))
;; If they don't properly match, use a different face,
;; or print a message.
(if mismatch
(progn
(and (null show-paren-mismatch-face)
(x-display-color-p)
(progn
(add-to-list 'facemenu-unlisted-faces
'paren-mismatch)
(make-face 'paren-mismatch)
(or (face-nontrivial-p 'paren-mismatch t)
(progn
(set-face-background 'paren-mismatch
"purple")
(set-face-foreground 'paren-mismatch
"white")))
(setq show-paren-mismatch-face 'paren-mismatch)))
(if show-paren-mismatch-face
(setq face show-paren-mismatch-face)
(message "Paren mismatch"))))
)))
(cond (pos
(if (or (= dir -1)
(not (integerp pos)))
;; 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.
(let ((from (if (= dir 1)
(point)
(forward-point -1)))
(to (if (= dir 1)
(forward-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)))
;; Always set the overlay face, since it varies.
(overlay-put show-paren-overlay-1 'face face))
;; Otherwise, turn off any such highlighting.
(and show-paren-overlay-1
(overlay-buffer show-paren-overlay-1)
(delete-overlay show-paren-overlay-1)))
;; Turn on highlighting for the matching paren, if found.
;; If it's an unmatched paren, turn off any such highlighting.
(or (and (not (integerp pos))
(delete-overlay show-paren-overlay))
(save-excursion
(goto-char pos)
(if show-paren-overlay
(move-overlay show-paren-overlay
(forward-point (- dir))
pos
(current-buffer))
(setq show-paren-overlay
(make-overlay (forward-point (- dir)) pos)))))
;; Always set the overlay face, since it varies.
(overlay-put show-paren-overlay 'face face))
(t
;; 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)))))))
(when window-system
(let (pos dir mismatch face (oldpos (point)))
(cond ((eq (char-syntax (preceding-char)) ?\))
(setq dir -1))
((eq (char-syntax (following-char)) ?\()
(setq dir 1)))
;;
;; Find the other end of the sexp.
(when dir
(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)))
;; 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)))
(when (/= (char-syntax (char-after beg)) ?\$)
(setq mismatch
(not (eq (char-before end)
;; This can give nil.
(matching-paren (char-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
(setq face 'show-paren-mismatch-face)
(setq face 'show-paren-match-face))
;;
;; 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 (= 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)
(forward-point -1)))
(to (if (= dir 1)
(forward-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)))
;; Always set the overlay face, since it varies.
(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.
(unless (integerp pos)
(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)
(forward-point (- dir))))))
(if show-paren-overlay
(move-overlay show-paren-overlay from to (current-buffer))
(setq show-paren-overlay (make-overlay from to))))
;;
;; Always set the overlay face, since it varies.
(overlay-put show-paren-overlay 'face face)))))
(provide 'paren)
......
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