From b2f8c9f96fbda53387b9f910d3b97aefefab6cab Mon Sep 17 00:00:00 2001 From: Stefan Monnier Date: Mon, 4 Jan 2021 00:59:56 -0500 Subject: [PATCH] * src/xdisp.c (syms_of_xdisp): New var redisplay-skip-fontification-on-input (handle_fontified_prop): Use it. * src/keyboard.h (input_was_pending): Declare. * src/keyboard.c (input_was_pending): Make non-static. --- etc/NEWS | 6 ++++++ src/keyboard.c | 2 +- src/keyboard.h | 2 +- src/xdisp.c | 14 ++++++++++++++ 4 files changed, 22 insertions(+), 2 deletions(-) diff --git a/etc/NEWS b/etc/NEWS index 8003175a83a..d8f25ab362e 100644 --- a/etc/NEWS +++ b/etc/NEWS @@ -212,6 +212,12 @@ This makes debugging Emacs Lisp scripts run in batch mode easier. To get back the old behavior, set the new variable 'backtrace-on-error-noninteractive' to a nil value. +** 'redisplay-skip-fontification-on-input' helps Emacs keep up with fast input. +This is another attempt to solve the problem of handling high key repeat rate +and other "slow scrolling" situations. It is hoped it behaves better +than 'fast-but-imprecise-scrolling' and 'jit-lock-defer-time'. +It is not enabled by default. + * Editing Changes in Emacs 28.1 diff --git a/src/keyboard.c b/src/keyboard.c index d2f0cb405f0..cf15cd73572 100644 --- a/src/keyboard.c +++ b/src/keyboard.c @@ -285,7 +285,7 @@ bool input_pending; with the input rate, but if it can keep up just enough that there's no input_pending when we begin the command, then redisplay is not skipped which results in better feedback to the user. */ -static bool input_was_pending; +bool input_was_pending; /* Circular buffer for pre-read keyboard input. */ diff --git a/src/keyboard.h b/src/keyboard.h index 91c6f4604f9..8bdffaa2bff 100644 --- a/src/keyboard.h +++ b/src/keyboard.h @@ -432,7 +432,7 @@ extern int parse_solitary_modifier (Lisp_Object symbol); extern Lisp_Object real_this_command; extern int quit_char; - +extern bool input_was_pending; extern unsigned int timers_run; extern bool menu_separator_name_p (const char *); diff --git a/src/xdisp.c b/src/xdisp.c index 749893baad6..43447e2bf7e 100644 --- a/src/xdisp.c +++ b/src/xdisp.c @@ -4262,6 +4262,7 @@ handle_fontified_prop (struct it *it) if (!STRINGP (it->string) && it->s == NULL && !NILP (Vfontification_functions) + && !(input_was_pending && redisplay_skip_fontification_on_input) && !NILP (Vrun_hooks) && (pos = make_fixnum (IT_CHARPOS (*it)), prop = Fget_char_property (pos, Qfontified, Qnil), @@ -35598,6 +35599,19 @@ best except in special circumstances such as running redisplay tests in batch mode. */); redisplay_skip_initial_frame = true; + DEFVAR_BOOL ("redisplay-skip-fontification-on-input", + redisplay_skip_fontification_on_input, + doc: /* Skip `fontification_functions` when there is input pending. +If non-nil and there was input pending at the beginning of the command, +the `fontification_functions` hook is not run. This usually does not +affect the display because redisplay is completely skipped anyway if input +was pending, but it can make scrolling smoother by avoiding +unnecessary fontification. +It is similar to `fast-but-imprecise-scrolling' with similar tradeoffs, +but with the advantage that it should only affect the behavior when Emacs +has trouble keeping up with the incoming input rate. */); + redisplay_skip_fontification_on_input = false; + DEFVAR_BOOL ("redisplay-adhoc-scroll-in-resize-mini-windows", redisplay_adhoc_scroll_in_resize_mini_windows, doc: /* If nil always use normal scrolling in minibuffer windows. -- 2.39.5