🚀 go-pugleaf

In article <5348@crdgw1.crd.ge.com> Bruce Barnett writes:

> I have seen a lot of people on the net "judge" Motif vs. Open Look
> mostly on the overall look of a UI, or else they select it because it
> is what their vendor has supplied.
> 
> ...
> 
> 	How convenient is the scrollbar?

Good question.

How many times have you had to check, very carefully, a large number
of lines of text, one by one? In such a situation:

    A. You want to scroll exactly one line at a time.

    B. If you accidentally go too far, you want to scroll back one line.

    C. Or you may want to scroll exactly one page at a time.

Now let's see how well some scrollbars meet these requirements. I
obviously don't know about all existing scrollbars, but here are some.
I expect that the NeWS people and others will follow up about
scrollbars that I do not mention.


X11R4 Athena scrollbar

 A. This scrollbar returns the position of the mouse relative to the end
    of the scrollbar when pointer button 1 or 3 is pressed. Xterm, for
    example, uses this distance to determine how much to scroll. So it is
    very difficult to find out where to position the mouse to scroll
    exactly one line. Of course, it is up to the application to decide
    what to do with the value returned by the scrollbar, but in any case,
    the appearance of the scrollbar does not make it immediately obvious
    to the user what needs to be done to scroll exactly one line.

 B. This scrollbar makes it easy to scroll up or down using pointer button
    1 or 3.

 C. It is difficult to scroll exactly one page (see above).


Motif & HP(Xw) scrollbars

 A. The arrows at the ends of the scrollbar make it easy to scroll exactly
    one line.

 B. Since the arrows are at the ends of the scrollbar, the user must move
    the mouse all the way to the other end to scroll in the other
    direction.

 C. It is impossible to scroll exactly one page.


Open Look scrollbar

 A. The arrows in the elevator make it easy to scroll exactly one line.

 B. Though the arrows are close together, the user must still move the
    mouse to scroll in the other direction.

 C. It is easy to scroll exactly one page, once the user finds out that
    clicking beneath the elevator can be used for this purpose.


X10R4 xterm scrollbar (a classic)

 A. The up-and-down arrow button makes it easy to scroll exactly one line.

 B. Since the up arrow and down arrow are in one area, it is easy to
    scroll in either direction using mouse buttons 1 and 3.

 C. It is easy to scroll exactly one page, once the user finds out that
    the shift key is held down for this purpose.


I could go on and on about the user interface, and also about the
programmer's interface, but I think I'll stop here.

Just one last thing: I have hacked the Xw scrollbar to produce one
that meets all of my 3 requirements. I could send copies to anyone who
is interested.


Erik M. van der Poel                  erik@sra.co.jp             (Japan)
SRA, 1-1-1 Hirakawa-cho, Chiyoda-ku   erik%sra.co.jp@uunet.uu.net  (USA)
Tokyo 102 Japan. TEL +81-3-234-2692   erik%sra.co.jp@mcvax.uucp (Europe)