Subject: Re: bug#32002: 24.4; Scroll bar start, end not correct

From: Mike Kupfer <[email-masked]>
Date: Tue, 03 Jul 2018 22:13:01 -0700

Andrew Kurn wrote:

> Anyhow, my contention is that, since the whole buffer is on display,
> the scroll bar should extend over the whole window.  The length of the
> scroll bar, as a fraction of the window height, is supposed to be the
> fraction of the buffer on display.  Its top is the character (line,
> usually) where the display starts.  Its bottom is where it stops.

That's what I would expect, too.  The current behavior was explained to
me as deliberate, to account for differences in scrolling behavior when
comparing Emacs to GTK apps like gedit.  That is, when you get to the
end of a file in gedit, the last line of the file is at the bottom of
the window.  If you get to the bottom of the file and continue to press
PgDown or the down arrow key, gedit just beeps at you.

With Emacs, though, it is possible, using PgDown or C-v, to scroll down
so that the last line of the file appears higher up in the window,
possibly even at the very top of the window.

There does seem to be an inconsistency between the scrollbar and
scrolling using keypresses.  For example, in the attached screenshot, if
I try to scroll using PgDown, C-v, or down arrow, I get an "End of
buffer" error.  Yet I can scroll down using the down-stepper on the
scrollbar.  And if I drag the scrollbar marker down as far as it will
go, the text scrolls off the top, leaving me with a blank window.

Personally, I find the gap below the scrollbar marker disorienting; I
can't trust the scrollbar to show me when I'm at the end of the file.
This is annoying enough that I try to avoid Emacs+GTK.

mike