Re: Flipping for scrolled windows

["Nadav Har'El" <nyh math technion ac il>]

On Tue, Sep 25, 2001, Steve Underwood wrote about "Re: Flipping for scrolled windows":
> Not quite so much, maybe, but there is still substantial benefit in the
> left hand scroll bar. I think we only use right hand scroll bars because
> someone way back did it, nobody bothered with any ergonomic assessment,
> and now its written in tablets of stone that right hand bars are right.

I always assumed that the right-hand scroll bar (in most LTR applications
except xterm by default) was a deliberate decision, and stems from the fact
that people tend to "cut-and-paste" text from a beginning of a line, and when
the scrollbar is on the left it is very easy to accidentally click on it
instead of the beginning of the line - and since clicking on a scrollbar has
immediate consequences (again, in most applications but not in xterm) this
got annoying.

Granted, this means that when you actually do want to move between cutting-
and-pasting to scrolling you need to move the mouse pointer the whole
window's width. But this is not too hard, and to make it even less hard many
applications have scrolling keyboard shortcuts, like page-up/down and
arrow keys, and many mice have scroll wheels now. Tcl/Tk even had a (very
interesting) mouse binding which let you scroll the window by dragging the
middle mouse button anywhere in the scrollable window (very similarly to
what the mouse scroll wheel does now).

If this is the reason why a right-hand scrollbar was chosen (and not some
silly "tradition"), then when the window contains mostly RTL text, the
scrollbar's side should indeed be switched to the left, again to keep it away
from beginnings of lines.

This opens up another question, however: in an application like a text
editor, what happens if the user-interface and menus is RTL (say, in Hebrew)
but the actual edited text is LTR (say, a C program)? The above away-from-
beginnings-of-lines idea suggests that the side of the scrollbar should be
chosen according to the direction of the actual scrolled window (in this
case the LTR C program), not of the user interface.

I'm not sure I agree with Tzafrir that it bothers people that some windows
on the screen will have left scroll-bars and others right scroll-bars, as
this is already the norm for me: all my xterm windows have scroll bars on the
left, and my xemacs and gvim windows all have scroll bars on the right, for
example.

The situation for "iconize" buttons (and other window manager decorations)
is different - since the window manager is a single application, it should
put the same decorations on all windows, without regard to the language
shown inside the window. It probably can't do anything else, by the way,
because I don't think the ICCCM provides any way for a window to tell the
window manager the language or directionality inside it (but I might be wrong
in this - I didn't go back to the ICCCM to look).

P.S. It's interesting to note that other types of platforms have other
reasons for choosing the location of the scroll-bar. For example, the
Palm Pilot has scroll-bars on the right, and this is a very deliberate
decision, designed for right-handed people: A right-handed person holds
the stylus in their right hand, and so can move the scrollbar on the right-
hand side without obscuring the text that is being scrolled with their
hand. If the scroll-bar was on the left, the right hand moving the stylus
across the scroll-bar on the left would at the same time obscure the text
that the user needs to see. "Hacks" are available to move scroll-bars to
the left, for left-handed users.
So in the Palm's case, it is important to choose the side of the scroll-bar
according to the user's choice of hands, not to their choice of language.
In this case, the away-from-beginnings-of-lines issue is secondary, but
nicely coincides with the away-from-bol choice for the "typical" right-handed-
English-speaker case. (I'm left-handed by the way, so please don't blame
me for politically-incorrectness ;)).


-- 
Nadav Har'El                        |      Tuesday, Sep 25 2001, 8 Tishri 5762
nyh math technion ac il             |-----------------------------------------
Phone: +972-53-245868, ICQ 13349191 |Microchips: what's left at the bottom of
http://nadav.harel.org.il           |the bag when it reaches you.