From: Keith David Bershatsky <esq@lawlist.com>
To: Eli Zaretskii <eliz@gnu.org>
Cc: 29002@debbugs.gnu.org
Subject: bug#29002: it.first_visible_x is erroneously 0 while horizontal scrolling.
Date: Sun, 29 Oct 2017 13:12:15 -0700 [thread overview]
Message-ID: <m2fua167ds.wl%esq@lawlist.com> (raw)
In-Reply-To: <m2h8umbu0k.wl%esq@lawlist.com>
Horizontal scroll bars are not visible in this example. I have been using the horizontal mouse-wheel. I can reproduce the issue by evaluating (scroll-right 1) in the minibuffer when at the end of a long-line, and then pressing the left arrow-key, and then calling F5 (bound to bug-hscroll).
It appears to me that (scroll-right 1) is kind of a temporary form of horizontal scrolling, which automatically cancels as to non-current lines in a vareity of situations when keyboard input is received. Plain old scroll-right without the optional distance argument is semi-permanent, and non-current lines do not automatically return to a non-scrolled state.
F8 is undefined on OSX, but I saw in a grep search that "C-x >" is bound to scroll-right. That behaves differently than (scroll-right 1) using the optional argument to control the distance. I also tried using "C-u 1 C-x >", but it behaves the same as "C-x >".
The issue described in #29002 is not present when invoking "C-u 1 C-x >" or "C-x >" -- i.e., both of which appear to be semi-permanent forms of horizontal scrolling.
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DATE: [10-29-2017 12:23:33] <29 Oct 2017 21:23:33 +0200>
FROM: Eli Zaretskii <eliz@gnu.org>
>
> > Date: Sun, 29 Oct 2017 11:56:22 -0700
> > From: Keith David Bershatsky <esq@lawlist.com>
> > Cc: 29002@debbugs.gnu.org
> >
> > I agree ... and that leads us to bug #29002. :)
> >
> > In the normal situation, the screen refreshes when the arrow key is used and non-current lines cease to be horizontally scrolled. In the current example, however, non-current lines remain horizontally scrolled and Emacs "thinks" that they are not. When I say that Emacs "thinks" they are not, I am referring to IT.
>
> What Emacs "thinks" is on display. And there we see hscrolled lines.
> So first_visible_x must be non-zero, and that is what I see. If
> first_visible_x were zero, you'd see the line's text starting with the
> first character of each line. I very much doubt that this is somehow
> Windows-specific, since xdisp.c is the platform-independent part of
> the display engine.
>
> Or maybe the horizontal scroll bar on macOS somehow causes this. What
> happens if you scroll-right with some key, like F8, and not with the
> mouse?
>
> (In any case, invoking scroll-right in this situation makes very
> little sense to me.)
next prev parent reply other threads:[~2017-10-29 20:12 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-26 1:03 bug#29002: it.first_visible_x is erroneously 0 while horizontal scrolling Keith David Bershatsky
2017-10-26 3:45 ` Keith David Bershatsky
2017-10-26 4:51 ` Eli Zaretskii
2017-10-26 6:20 ` Keith David Bershatsky
2017-10-26 15:56 ` Eli Zaretskii
2017-10-26 18:56 ` Keith David Bershatsky
2017-10-29 11:23 ` Eli Zaretskii
2017-10-29 17:29 ` Keith David Bershatsky
2017-10-29 18:29 ` Eli Zaretskii
2017-10-29 18:56 ` Eli Zaretskii
2017-10-29 18:56 ` Keith David Bershatsky
2017-10-29 19:23 ` Eli Zaretskii
2017-10-29 19:08 ` Keith David Bershatsky
2017-10-29 20:12 ` Keith David Bershatsky [this message]
2017-10-30 18:02 ` Eli Zaretskii
2017-10-30 19:36 ` Keith David Bershatsky
2017-11-04 9:32 ` Eli Zaretskii
2017-11-05 0:16 ` Keith David Bershatsky
2017-11-05 9:15 ` Keith David Bershatsky
2017-11-05 10:44 ` Eli Zaretskii
2017-11-05 16:59 ` Keith David Bershatsky
2017-11-05 18:12 ` Eli Zaretskii
2017-11-06 1:05 ` Keith David Bershatsky
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