From 299bd316cd172f3a71705ab33efbf23590241e15 Mon Sep 17 00:00:00 2001 From: Shynur Date: Tue, 2 May 2023 01:32:44 +0800 Subject: [PATCH] Display matched offscreen open paren with a distinct face Propertize matched offscreen openparen that is showing in the echo area in order to make it prominent; use shadow face for non-context characters (i.e., 'Matches') for the same purpose. * lisp/simple.el (blink-matching-paren-offscreen): Add this face for highlighting. * lisp/simple.el (blink-matching-paren-highlight-offscreen): Add this option to toggle face `blink-matching-paren-offscreen'. * lisp/simple.el (blink-paren-open-paren-line-string): Propertize the matched offscreen openparen with a face conditionally. (Bug#63089) --- lisp/simple.el | 87 ++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 67 insertions(+), 20 deletions(-) diff --git a/lisp/simple.el b/lisp/simple.el index b621e1603bd..e4a0b9549e0 100644 --- a/lisp/simple.el +++ b/lisp/simple.el @@ -9215,6 +9215,21 @@ it skips the contents of comments that end before point." :type 'boolean :group 'paren-blinking) +(defcustom blink-matching-paren-highlight-offscreen nil + "If non-nil, highlight showing in the echo area matched off-screen open paren. +This highlighting uses face `blink-matching-paren-offscreen'." + :type 'boolean + :version "30.1" + :group 'paren-blinking) + +(defface blink-matching-paren-offscreen + '((t :foreground "green")) + "Face for showing in the echo area matched open paren that is off-screen. +This face will not be used when `blink-matching-paren-highlight-offscreen' +is nil." + :version "30.1" + :group 'paren-blinking) + (defun blink-matching-check-mismatch (start end) "Return whether or not START...END are matching parens. END is the current point and START is the blink position. @@ -9312,47 +9327,79 @@ The function should return non-nil if the two tokens do not match.") (delete-overlay blink-matching--overlay))))) ((not show-paren-context-when-offscreen) (minibuffer-message - "Matches %s" - (substring-no-properties - (blink-paren-open-paren-line-string blinkpos)))))))) + #("Matches %s" + ;; Make the following text (i.e., %s) prominent. + 0 7 (face shadow)) + (blink-paren-open-paren-line-string blinkpos))))))) (defun blink-paren-open-paren-line-string (pos) - "Return the line string that contains the openparen at POS." + "Return the line string that contains the openparen at POS. +Remove the line string's properties but give the openparen a +face if `blink-matching-paren-highlight-offscreen' is non-nil." (save-excursion (goto-char pos) ;; Capture the regions in terms of (beg . end) conses whose ;; buffer-substrings we want to show as a context string. Ensure ;; they are font-locked (bug#59527). - (let (regions) - ;; Show what precedes the open in its line, if anything. + (let (regions + openparen-idx) (cond + ;; Show what precedes the open in its line, if anything. ((save-excursion (skip-chars-backward " \t") (not (bolp))) - (setq regions (list (cons (line-beginning-position) - (1+ pos))))) + (let ((bol (line-beginning-position))) + (setq regions (list (cons bol (1+ pos))) + openparen-idx (- pos bol)))) ;; Show what follows the open in its line, if anything. ((save-excursion (forward-char 1) (skip-chars-forward " \t") (not (eolp))) - (setq regions (list (cons pos (line-end-position))))) + (setq regions (list (cons pos (line-end-position))) + openparen-idx 0)) ;; Otherwise show the previous nonblank line, ;; if there is one. ((save-excursion (skip-chars-backward "\n \t") (not (bobp))) - (setq regions (list (cons (progn - (skip-chars-backward "\n \t") - (line-beginning-position)) - (progn (end-of-line) - (skip-chars-backward " \t") - (point))) + (setq regions (list (cons + (let (bol) + (skip-chars-backward "\n \t") + (setq bol (line-beginning-position) + openparen-idx (- bol)) + bol) + (let (eol) + (end-of-line) + (skip-chars-backward " \t") + (setq eol (point) + openparen-idx (+ openparen-idx + eol + ;; (length "...") + 3)) + eol)) (cons pos (1+ pos))))) ;; There is nothing to show except the char itself. - (t (setq regions (list (cons pos (1+ pos)))))) + (t (setq regions (list (cons pos (1+ pos))) + openparen-idx 0))) ;; Ensure we've font-locked the context region. (font-lock-ensure (caar regions) (cdar (last regions))) - (mapconcat (lambda (region) - (buffer-substring (car region) (cdr region))) - regions - "...")))) + (let ((line-string + (mapconcat + (lambda (region) + (buffer-substring (car region) (cdr region))) + regions + "...")) + (openparen-next-char-idx (1+ openparen-idx))) + (setq line-string (substring-no-properties line-string)) + (concat + (substring line-string + 0 openparen-idx) + (let ((matched-offscreen-openparen + (substring line-string + openparen-idx openparen-next-char-idx))) + (if blink-matching-paren-highlight-offscreen + (propertize matched-offscreen-openparen + 'face 'blink-matching-paren-offscreen) + matched-offscreen-openparen)) + (substring line-string + openparen-next-char-idx)))))) (defvar blink-paren-function 'blink-matching-open "Function called, if non-nil, whenever a close parenthesis is inserted. -- 2.39.5