Re: WHAT MOVES ON SCREEN?

["David L. Bergart" <bodafu -at- CCVAX -dot- SINICA -dot- EDU -dot- TW>]

Matt Hicks <matt -at- UNIDATA -dot- UCAR -dot- EDU> comments

  >My take on this is that neither the data nor the window "moves". A
  >graphical representation of the data is redisplayed at a number of
  >positions within a window, but the data itself remains in a fixed
  >location in memory. If you think that either the data or the window
  >moves, then what is happening when you relocate a window on your desktop?
  >Both the "data" and the window move. If either of the proposed models
  >were accurate portrayals of reality, I would expect to see different
  >"data" in the window when it arrived at its new location.

  >I think this topic is amusing and interesting as a kind of mind expansion
  >exercise, but ultimately it's just mental masturbation.




A person who is using a WYSIWYG-type wordprocessor doesn't (or shouldn't need
to) think about the internal representation of the text or the mechanism of
presentation. Even though I've written editors and have a pretty clear idea of
what is really happening, when I USE an editor I work with the visual paradigm
of moving viewports on stationary text because it maps onto what I do when
writing with a pen on paper. If I'm writing at the bottom of the page and want
to see what's at the top, I move my gaze up -- I do NOT slid the page down
(unless I have a hangover 8-). If I wanted to think about pointers and buffers
and good stuff like that, I'd use TECO or some other line editor. I think that
the demise of such crude (though often powerful) editors indicates that modern
editor-users just want to write -- they don't want to count characters to
determine where to insert and they don't want to consider the internal data
strucures.

So...how do we describe to them (or to ourselves) the important and possibly
confusing virtual relationship between imaginary text inside the machine and
the 'window' through which we see it. I submit that mapping the direction
of the arrow keys onto the sweep of a virtual gaze is the most natural.

One could argue that the wordprocessor is a machine for manipulating text,
and that when an arrow key is pressed, the text should be manipulated in the
manor indicated -- the up arrow moves the text up relative to the machine.
This, however, focuses on the tool rather than on the work to be done.

It is NOT "just mental masturbation" for a tech writer to question this, or
even to beat on it (and on the programers, if necessary) till a useful answer
is found.


BTW, when you move a window on the screen the data DOES get left behind, but
the motion of the Earth through space causes it to catch up to the window and
be displayed properly.

David


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                                              bodafu -at- ccvax -dot- sinica -dot- edu -dot- tw