bug#40278: 27.0.90; Flickering in Windows 10

[Eli Zaretskii]

> From: Nicolas Bértolo <nicolasbertolo@gmail.com>
> Date: Tue, 31 Mar 2020 12:51:37 -0300
> Cc: Noam Postavsky <npostavs@gmail.com>, Eli Zaretskii <eliz@gnu.org>, 
> 40278@debbugs.gnu.org
> 
> > I have no idea why this should be related to scrolling.  Does any of
> > these happen with a normal frame put on top of the window you scroll?
> 
> I think it is not possible to input into a frame that is partially hidden (and
> thus not focused) by others in Windows. The mouse wheel does nothing and
> keyboard inputs go to the topmost window.

It's possible, but you need to turn on the "active window tracking"
feature.  There are tiny programs floating around that allow you to do
that.  With that feature turned on, focus follows the mouse, like on X
Window system on Unix.