* bug#12801: 24.3.50; `scroll-conservatively' and `scroll-step'
@ 2012-11-04 21:24 Dani Moncayo
2012-11-05 3:53 ` Eli Zaretskii
0 siblings, 1 reply; 6+ messages in thread
From: Dani Moncayo @ 2012-11-04 21:24 UTC (permalink / raw)
To: 12801
[-- Attachment #1: Type: text/plain, Size: 2042 bytes --]
Recipe from "emacs -nw -Q" (the "-nw" part is not strictly needed, but
it is cleaner for showing the problem):
1. Set the variable `scroll-step' to 3.
2. Visit the attached file.
3. Adjust the vertical space (empty lines) between "first line" and
"last visible line" until the latter becomes indeed the last visible
line in the window.
4. Move point to the "last visible line".
5. Move point two lines down in a single command: C-u 2 C-n
I observe that after step #5 the window is scrolled by `scroll-step'
lines (3 lines), which is TRT.
But if I set `scroll-conservatively' to 1 and repeat the experiment
(from step #4), then I observe that this time the line where point
goes to ("2") is centered in the window.
After reading (info "(emacs) Auto Scrolling"), I think that this is
either a bug in the program or in the documentation. This paragraph
in particular doesn't match the observed behavior in the second case:
The variable `scroll-step' determines how many lines to scroll the
window when point moves off the screen. If moving by that number of
lines fails to bring point back into view, point is centered instead.
The default value is zero, which causes point to always be centered
after scrolling.
In GNU Emacs 24.3.50.1 (i386-mingw-nt6.1.7601)
of 2012-11-04 on MS-W7-DANI
Bzr revision: 110794 rgm@gnu.org-20121104041313-7j1z7vaqtrgopt26
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
`configure --with-gcc (4.7) --no-opt --enable-checking --cflags
-I../../libs/libXpm-3.5.10/include -I../../libs/libXpm-3.5.10/src
-I../../libs/libpng-1.2.37-lib/include -I../../libs/zlib-1.2.5
-I../../libs/giflib-4.1.4-1-lib/include
-I../../libs/jpeg-6b-4-lib/include
-I../../libs/tiff-3.8.2-1-lib/include
-I../../libs/libxml2-2.7.8-w32-bin/include/libxml2
-I../../libs/gnutls-3.0.9-w32-bin/include
-I../../libs/libiconv-1.9.2-1-lib/include'
Important settings:
value of $LANG: ESN
locale-coding-system: cp1252
default enable-multibyte-characters: t
--
Dani Moncayo
[-- Attachment #2: test.txt --]
[-- Type: text/plain, Size: 107 bytes --]
first line
last visible line
1
2
3
4
5
6
^ permalink raw reply [flat|nested] 6+ messages in thread* bug#12801: 24.3.50; `scroll-conservatively' and `scroll-step'
2012-11-04 21:24 bug#12801: 24.3.50; `scroll-conservatively' and `scroll-step' Dani Moncayo
@ 2012-11-05 3:53 ` Eli Zaretskii
2012-11-05 7:33 ` Dani Moncayo
2012-11-05 18:03 ` Eli Zaretskii
0 siblings, 2 replies; 6+ messages in thread
From: Eli Zaretskii @ 2012-11-05 3:53 UTC (permalink / raw)
To: Dani Moncayo; +Cc: 12801
> Date: Sun, 4 Nov 2012 22:24:53 +0100
> From: Dani Moncayo <dmoncayo@gmail.com>
>
> 1. Set the variable `scroll-step' to 3.
> 2. Visit the attached file.
> 3. Adjust the vertical space (empty lines) between "first line" and
> "last visible line" until the latter becomes indeed the last visible
> line in the window.
> 4. Move point to the "last visible line".
> 5. Move point two lines down in a single command: C-u 2 C-n
>
> I observe that after step #5 the window is scrolled by `scroll-step'
> lines (3 lines), which is TRT.
>
> But if I set `scroll-conservatively' to 1 and repeat the experiment
> (from step #4), then I observe that this time the line where point
> goes to ("2") is centered in the window.
>
> After reading (info "(emacs) Auto Scrolling"), I think that this is
> either a bug in the program or in the documentation. This paragraph
> in particular doesn't match the observed behavior in the second case:
>
> The variable `scroll-step' determines how many lines to scroll the
> window when point moves off the screen. If moving by that number of
> lines fails to bring point back into view, point is centered instead.
> The default value is zero, which causes point to always be centered
> after scrolling.
If you set scroll-conservatively, scroll-step is ignored for the
purposes of deciding how much to scroll when point is off the window.
So the code works as intended. The documentation is not wrong, as it
describes scroll-conservatively before scroll-step, and the
description quite naturally should lead one to the above conclusion,
because these two variables contradict each other. I will make the
documentation more clear on this, though.
^ permalink raw reply [flat|nested] 6+ messages in thread* bug#12801: 24.3.50; `scroll-conservatively' and `scroll-step'
2012-11-05 3:53 ` Eli Zaretskii
@ 2012-11-05 7:33 ` Dani Moncayo
2012-11-05 7:36 ` Dani Moncayo
2012-11-05 18:03 ` Eli Zaretskii
1 sibling, 1 reply; 6+ messages in thread
From: Dani Moncayo @ 2012-11-05 7:33 UTC (permalink / raw)
To: Eli Zaretskii; +Cc: 12801
> If you set scroll-conservatively, scroll-step is ignored for the
> purposes of deciding how much to scroll when point is off the window.
> So the code works as intended. The documentation is not wrong, as it
> describes scroll-conservatively before scroll-step, and the
> description quite naturally should lead one to the above conclusion,
> because these two variables contradict each other.
Obviously I disagree.
> I will make the
> documentation more clear on this, though.
Thank you. IMO that clarification is clearly needed.
--
Dani Moncayo
^ permalink raw reply [flat|nested] 6+ messages in thread
* bug#12801: 24.3.50; `scroll-conservatively' and `scroll-step'
2012-11-05 7:33 ` Dani Moncayo
@ 2012-11-05 7:36 ` Dani Moncayo
0 siblings, 0 replies; 6+ messages in thread
From: Dani Moncayo @ 2012-11-05 7:36 UTC (permalink / raw)
To: Eli Zaretskii; +Cc: 12801
>> If you set scroll-conservatively, scroll-step is ignored for the
>> purposes of deciding how much to scroll when point is off the window.
>> So the code works as intended. The documentation is not wrong, as it
>> describes scroll-conservatively before scroll-step, and the
>> description quite naturally should lead one to the above conclusion,
>> because these two variables contradict each other.
>
> Obviously I disagree.
I mean: I read the info node several times and I couldn't figure out
the intended behavior you've just described when both variables are
set.
--
Dani Moncayo
^ permalink raw reply [flat|nested] 6+ messages in thread
* bug#12801: 24.3.50; `scroll-conservatively' and `scroll-step'
2012-11-05 3:53 ` Eli Zaretskii
2012-11-05 7:33 ` Dani Moncayo
@ 2012-11-05 18:03 ` Eli Zaretskii
2012-11-05 19:12 ` Dani Moncayo
1 sibling, 1 reply; 6+ messages in thread
From: Eli Zaretskii @ 2012-11-05 18:03 UTC (permalink / raw)
To: dmoncayo; +Cc: 12801-done
> Date: Mon, 05 Nov 2012 05:53:52 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: 12801@debbugs.gnu.org
>
> So the code works as intended. The documentation is not wrong, as it
> describes scroll-conservatively before scroll-step, and the
> description quite naturally should lead one to the above conclusion,
> because these two variables contradict each other. I will make the
> documentation more clear on this, though.
Done in revision 110785 on the emacs-24 branch.
^ permalink raw reply [flat|nested] 6+ messages in thread
* bug#12801: 24.3.50; `scroll-conservatively' and `scroll-step'
2012-11-05 18:03 ` Eli Zaretskii
@ 2012-11-05 19:12 ` Dani Moncayo
0 siblings, 0 replies; 6+ messages in thread
From: Dani Moncayo @ 2012-11-05 19:12 UTC (permalink / raw)
To: Eli Zaretskii; +Cc: 12801-done
>> So the code works as intended. The documentation is not wrong, as it
>> describes scroll-conservatively before scroll-step, and the
>> description quite naturally should lead one to the above conclusion,
>> because these two variables contradict each other. I will make the
>> documentation more clear on this, though.
>
> Done in revision 110785 on the emacs-24 branch.
Thank you.
--
Dani Moncayo
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2012-11-05 19:12 UTC | newest]
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2012-11-04 21:24 bug#12801: 24.3.50; `scroll-conservatively' and `scroll-step' Dani Moncayo
2012-11-05 3:53 ` Eli Zaretskii
2012-11-05 7:33 ` Dani Moncayo
2012-11-05 7:36 ` Dani Moncayo
2012-11-05 18:03 ` Eli Zaretskii
2012-11-05 19:12 ` Dani Moncayo
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