--- Begin Message ---
Subject: |
24.3.50; `scroll-up/down-aggressively' don't seem to work as expected |
Date: |
Tue, 6 Nov 2012 00:27:55 +0100 |
Maybe I'm missing something, but after reading (info "(emacs) Auto
Scrolling") and the docstrings of the variables
`scroll-up/down-aggressively', the behavior I observe after playing a
bit doesn't seem right to me.
Recipe from "emacs -Q":
1. Visit the attached file.
2. Adjust the height of the Emacs GUI frame so that only lines 1 to 11
are visible. With this setup it is easy to tell the relative position
of a line in the window in terms of percentage from the top or bottom,
since each line counts as 10% for such percentages.
3. Go to line 1.
4. Type: C-u 1 5 C-n
--> Point goes to line 16, and that line is centered in the window. So
everything is as expected so far.
5. M-: (setq scroll-up-aggressively 0.7) <RET>
6. Repeat steps #3 and #4.
--> This time I observe that point goes to line 16, but that line is
near the bottom of the window (9th line; 20% from the bottom) when it
should be near the top (4th line; 70% from the bottom).
I also observe a misbehavior when testing scroll-down-aggressively:
1. M-: (setq scroll-down-aggressively 0.7) <RET>
2. Go to line 30 and make that line the last visible one.
3. Type: C-u 1 1 C-p
--> I observe that point goes to line 19, but that line is the 10th in
the window (90% from the top), when it should be the 8th line (70%
from the top).
In GNU Emacs 24.3.50.1 (i386-mingw-nt6.1.7601)
of 2012-11-05 on MS-W7-DANI
Bzr revision: 110809 address@hidden
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
test.txt
Description: Text document
--- End Message ---
--- Begin Message ---
Subject: |
Re: bug#12811: 24.3.50; `scroll-up/down-aggressively' don't seem to work as expected |
Date: |
Sun, 11 Nov 2012 18:19:13 +0200 |
> Date: Sun, 11 Nov 2012 14:33:33 +0100
> From: Dani Moncayo <address@hidden>
> Cc: address@hidden
>
> The second test (related to `scroll-down-aggressively') produces a
> better result (point shown at line 9 - 80% from the top) but not the
> expected one (line 8 - 70% from the top).
Emacs doesn't count in lines, it counts in pixels. And since a line
has a finite size, where exactly those 70% end is not well determined
(is it the top of the line, the bottom of the line, somewhere in
between?).
> In any case, since the result is almost the right one, and more
> importantly, since I've discovered that these two variables are not
> worth the trouble, I'm ok with closing this bug report now.
Thanks, closing.
--- End Message ---