From ece7425c22633196ae164cb6aa0e6d77fabe9f81 Mon Sep 17 00:00:00 2001 From: Augusto Stoffel Date: Wed, 27 Jan 2021 16:09:38 +0100 Subject: [PATCH] Reduce flicker in Isearch mode Lazy highlighting now happens immediately when the search string is at least as long as the value of the new custom variable `lazy-highlight-no-delay-length`. Also avoid updating the lazy count in the echo area too often. * isearch.el (lazy-highlight-no-delay-length): New defcustom. * isearch.el (lazy-lazy-count-format): Avoid a momentarily incorrect count when reversing search direction. * isearch.el (isearch-lazy-highlight-new-loop): Avoid a call to `isearch-message` that is quickly succeed by a second echo area update, thus causing flicker. * isearch.el (isearch-lazy-highlight-new-loop): Start lazy highlight immediately if appropriate. * etc/NEWS: Announce the change. * doc/emacs/search.texi: Document `lazy-highlight-no-delay-length'. Copyright-paperwork-exempt: yes --- doc/emacs/search.texi | 7 +++++++ etc/NEWS | 7 +++++++ lisp/isearch.el | 23 +++++++++++++++++++---- 3 files changed, 33 insertions(+), 4 deletions(-) diff --git a/doc/emacs/search.texi b/doc/emacs/search.texi index 637867b8115..f3c42bcea7f 100644 --- a/doc/emacs/search.texi +++ b/doc/emacs/search.texi @@ -2027,6 +2027,13 @@ highlighting: @item lazy-highlight-initial-delay @vindex lazy-highlight-initial-delay Time in seconds to wait before highlighting visible matches. +Applies only if the search string is less than +@code{lazy-highlight-no-delay-length} characters long. + +@item lazy-highlight-no-delay-length +@vindex lazy-highlight-no-delay-length +For search strings at least as long as the value of this variable, +lazy highlighting of matches starts immediately. @item lazy-highlight-interval @vindex lazy-highlight-interval diff --git a/etc/NEWS b/etc/NEWS index 7b4b7fea5a2..483375e8a2e 100644 --- a/etc/NEWS +++ b/etc/NEWS @@ -226,6 +226,13 @@ C-M- instead of . Either variant can be used as input; functions such as 'kbd' and 'read-kbd-macro' accept both styles as equivalent (they have done so for a long time). ++++ +** New user option 'lazy-highlight-no-delay-length'. +Lazy highlighting of matches in Isearch now starts immediately if the +search string is at least this long. 'lazy-highlight-initial-delay' +still applies for shorter search strings, which avoids flicker in the +search buffer due to too many matches being highlighted. + * Editing Changes in Emacs 28.1 diff --git a/lisp/isearch.el b/lisp/isearch.el index a1e3fe2c3f0..a6978a4c164 100644 --- a/lisp/isearch.el +++ b/lisp/isearch.el @@ -352,10 +352,20 @@ If this is nil, extra highlighting can be \"manually\" removed with :group 'lazy-highlight) (defcustom lazy-highlight-initial-delay 0.25 - "Seconds to wait before beginning to lazily highlight all matches." + "Seconds to wait before beginning to lazily highlight all matches. +This setting only has effect when the search string is less than +`lazy-highlight-no-delay-length' characters long." :type 'number :group 'lazy-highlight) +(defcustom lazy-highlight-no-delay-length 3 + "For search strings at least this long, lazy highlight starts immediately. +For shorter search strings, `lazy-highlight-initial-delay' +applies." + :type 'number + :group 'lazy-highlight + :version "28.1") + (defcustom lazy-highlight-interval 0 ; 0.0625 "Seconds between lazily highlighting successive matches." :type 'number @@ -3356,7 +3366,7 @@ isearch-message-suffix prompt. Otherwise, for isearch-message-prefix." (not isearch-error) (not isearch-suspended)) (format format-string - (if isearch-forward + (if isearch-lazy-highlight-forward isearch-lazy-count-current (if (eq isearch-lazy-count-current 0) 0 @@ -3916,7 +3926,8 @@ by other Emacs features." (clrhash isearch-lazy-count-hash) (setq isearch-lazy-count-current nil isearch-lazy-count-total nil) - (isearch-message))) + ;; Delay updating the message if possible, to avoid flicker + (when (string-equal isearch-string "") (isearch-message)))) (setq isearch-lazy-highlight-window-start-changed nil) (setq isearch-lazy-highlight-window-end-changed nil) (setq isearch-lazy-highlight-error isearch-error) @@ -3961,7 +3972,11 @@ by other Emacs features." (point-min)))) (unless (equal isearch-string "") (setq isearch-lazy-highlight-timer - (run-with-idle-timer lazy-highlight-initial-delay nil + (run-with-idle-timer (if (>= (length isearch-string) + lazy-highlight-no-delay-length) + 0 + lazy-highlight-initial-delay) + nil 'isearch-lazy-highlight-start)))) ;; Update the current match number only in isearch-mode and ;; unless isearch-mode is used specially with isearch-message-function -- 2.39.2