Units of scroll?

Subject: Units of scroll?
From: Geoff Hart <Geoff-h -at- MTL -dot- FERIC -dot- CA>
Date: Fri, 14 May 1999 12:58:48 -0400

Kathy Ellis posed the following problem: <<The app that I'm
documenting does not have scroll bars, but the programmer
has used that unit of measure for commands to move a map
on the screen. (He does not know what the unit of
measurement is, unfortunately.)>>

I'm really unclear on how you can define the amount of
scrolling that occurs if you "don't know what the unit of
measurement is"? From the user perspective, if there's no
scroll bar, then defining things in terms of scroll bars makes
absolutely no sense to me. Even if there were a scroll bar,
using it as the basis for movements is meaningless to the user;
maps aren't defined in terms of pages, after all.

explain the algorithm that the software uses for scrolling the
map, and base your choice of words on that algorithm (or
provide us with that additional information so we can take
another crack at it). If you're lucky, the measurement is based
on pixels, and the problem is trivial: for example, "Command
A moves the map one pixel at a time; command B moves it
10 pixels at a time." If you're extremely unlucky, it's based on
some ad hoc measurement the programmer came up with,
perhaps memory segmentation or something even more
obscure. Then, perhaps the best you can do would be to
describe movement in terms of "units and subunits" or some
such, and try to explain what these units mean.

<<And while you're at it...can God make a rock that is too
heavy for Him to lift?>>

That's a hoary old chestnut; the standard answers are "yes, but
why bother?" and "yes, but He wouldn't". Think of it this
way: If you decide you want to create something you can't
lift, you can arbitrarily pick a weight beyond which you won't
even subconsciously consider the possibility of lifting it. (This
works for human weightlifters too, btw.) As the sage Yoda
once said (and I'm paraphrasing from memory): "Do or do
not. There is no try."

--Geoff Hart @8^{)} Pointe-Claire, Quebec
geoff-h -at- mtl -dot- feric -dot- ca

"If pro is opposite of con, then what is the opposite of progress?"--Anon.

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