[OSM-talk] Oh look, a scale bar. But...

[Dermot McNally]

Hi,

I became aware of the new scale bar on the slippy map through another
thread over on dev. It's certainly nice to have one, and it was an
obvious absence that google maps (and others) had but OSM didn't.

However, we have copied an aspect of Google Maps that always annoyed
me. Paper maps frequently show both Metric and Imperial units, for the
valid reason that the publisher can't predict which of the two the
reader will prefer. That's a restriction that needn't apply to online
maps, though, and it has always seemed to me to be needless clutter.

>From what I can tell based on a quick look at the Openlayers
documentation, not only does it support single unit scale bars, that's
actually the default. For the slippy map, there seem to be a few
low-impact ways that we could improve the presentation:

* Make unit preference a profile element for logged-in users (in fact,
"dual" could be considered an option).

* For non-logged-in users, we could either continue to show a dual
scale _or_ there could be a unit-switching option on screen. We could
even toss users a cookie to help recall that preference if that
doesn't seem too evil.

Opinions?
Dermot