From 6b0e23412d367a3b90db01de9456431158525938 Mon Sep 17 00:00:00 2001
From: Po Lu <luangruo@yahoo.com>
Date: Tue, 22 Feb 2022 11:35:27 +0800
Subject: [PATCH] Improve momentum pixel scrolling on a non-selected window
* lisp/pixel-scroll.el (pixel-scroll-kinetic-state): New
argument `window'.
(pixel-scroll-start-momentum): Don't select the window under
the event when calculating velocity or redisplaying.
---
lisp/pixel-scroll.el | 102 ++++++++++++++++++++++---------------------
1 file changed, 52 insertions(+), 50 deletions(-)
diff --git a/lisp/pixel-scroll.el b/lisp/pixel-scroll.el
index 54724ca3285..463e106c7ac 100644
--- a/lisp/pixel-scroll.el
+++ b/lisp/pixel-scroll.el
@@ -699,11 +699,12 @@ wheel."
(message (error-message-string '(end-of-buffer))))))))))
(mwheel-scroll event nil))))
-(defun pixel-scroll-kinetic-state ()
- "Return the kinetic scroll state of the current window.
+(defun pixel-scroll-kinetic-state (&optional window)
+ "Return the kinetic scroll state of WINDOW.
+If WINDOW is nil, return the state of the current window.
It is a vector of the form [ VELOCITY TIME SIGN ]."
- (or (window-parameter nil 'kinetic-state)
- (set-window-parameter nil 'kinetic-state
+ (or (window-parameter window 'kinetic-state)
+ (set-window-parameter window 'kinetic-state
(vector (make-ring 30) nil nil))))
(defun pixel-scroll-accumulate-velocity (delta)
@@ -737,53 +738,54 @@ It is a vector of the form [ VELOCITY TIME SIGN ]."
(when pixel-scroll-precision-use-momentum
(let ((window (mwheel-event-window event))
(state nil))
- (with-selected-window window
- (setq state (pixel-scroll-kinetic-state))
- (when (and (aref state 1)
- (listp (aref state 0)))
- (condition-case nil
- (while-no-input
- (unwind-protect (progn
- (aset state 0 (pixel-scroll-calculate-velocity state))
- (when (> (abs (aref state 0))
- pixel-scroll-precision-momentum-min-velocity)
- (let* ((velocity (aref state 0))
- (original-velocity velocity)
- (time-spent 0))
- (if (> velocity 0)
- (while (and (> velocity 0)
- (<= time-spent
- pixel-scroll-precision-momentum-seconds))
- (when (> (round velocity) 0)
- (pixel-scroll-precision-scroll-up (round velocity)))
- (setq velocity (- velocity
- (/ original-velocity
- (/ pixel-scroll-precision-momentum-seconds
- pixel-scroll-precision-momentum-tick))))
- (redisplay t)
- (sit-for pixel-scroll-precision-momentum-tick)
- (setq time-spent (+ time-spent
- pixel-scroll-precision-momentum-tick))))
- (while (and (< velocity 0)
- (<= time-spent
- pixel-scroll-precision-momentum-seconds))
- (when (> (round (abs velocity)) 0)
+ (setq state (pixel-scroll-kinetic-state window))
+ (when (and (aref state 1)
+ (listp (aref state 0)))
+ (condition-case nil
+ (while-no-input
+ (unwind-protect (progn
+ (aset state 0 (pixel-scroll-calculate-velocity state))
+ (when (> (abs (aref state 0))
+ pixel-scroll-precision-momentum-min-velocity)
+ (let* ((velocity (aref state 0))
+ (original-velocity velocity)
+ (time-spent 0))
+ (if (> velocity 0)
+ (while (and (> velocity 0)
+ (<= time-spent
+ pixel-scroll-precision-momentum-seconds))
+ (when (> (round velocity) 0)
+ (with-selected-window window
+ (pixel-scroll-precision-scroll-up (round velocity))))
+ (setq velocity (- velocity
+ (/ original-velocity
+ (/ pixel-scroll-precision-momentum-seconds
+ pixel-scroll-precision-momentum-tick))))
+ (redisplay t)
+ (sit-for pixel-scroll-precision-momentum-tick)
+ (setq time-spent (+ time-spent
+ pixel-scroll-precision-momentum-tick))))
+ (while (and (< velocity 0)
+ (<= time-spent
+ pixel-scroll-precision-momentum-seconds))
+ (when (> (round (abs velocity)) 0)
+ (with-selected-window window
(pixel-scroll-precision-scroll-down (round
- (abs velocity))))
- (setq velocity (+ velocity
- (/ (abs original-velocity)
- (/ pixel-scroll-precision-momentum-seconds
- pixel-scroll-precision-momentum-tick))))
- (redisplay t)
- (sit-for pixel-scroll-precision-momentum-tick)
- (setq time-spent (+ time-spent
- pixel-scroll-precision-momentum-tick))))))
- (aset state 0 (make-ring 30))
- (aset state 1 nil)))
- (beginning-of-buffer
- (message (error-message-string '(beginning-of-buffer))))
- (end-of-buffer
- (message (error-message-string '(end-of-buffer))))))))))
+ (abs velocity)))))
+ (setq velocity (+ velocity
+ (/ (abs original-velocity)
+ (/ pixel-scroll-precision-momentum-seconds
+ pixel-scroll-precision-momentum-tick))))
+ (redisplay t)
+ (sit-for pixel-scroll-precision-momentum-tick)
+ (setq time-spent (+ time-spent
+ pixel-scroll-precision-momentum-tick))))))
+ (aset state 0 (make-ring 30))
+ (aset state 1 nil)))
+ (beginning-of-buffer
+ (message (error-message-string '(beginning-of-buffer))))
+ (end-of-buffer
+ (message (error-message-string '(end-of-buffer)))))))))
(defun pixel-scroll-interpolate-down ()
"Interpolate a scroll downwards by one page."
--
2.39.5