LatLongBoundingBox?

[Bernhard Reiter]

On Mon, Dec 27, 2004 at 01:34:26PM -0500, Russell Nelson wrote:
> Bernhard Reiter writes:
>  > >  > Another idea to work around the problems would to be to have an
>  > >  > outline mode that always makes at least one red dot when a layer is
>  > >  > outside the current view being to small or so.
>  > >  > Otherwise it mark the bounding box.
>  > > 
>  > > IMHO, if you have a layer which has been selected to be visible, and
>  > > its LatLonBoundingBox does not overlap the current map view, the
>  > > corner or edge closest to the data should say "LAYERNAME is over
>  > > there" with an arrow.  If you don't want to see that, and you *meant*
>  > > for the layer to be off the map, turn off its visibility.
>  > 
>  > This is something similiar to the red dot idea I outlined above.
> 
> I didn't quite understand the details of it.  Where is this red dot
> drawn?

It is not always a "dot", but red color.

Ascii art, indicating red color as "r"

 ______
|      |
|      |
|      |
 ------
        

layer inside the view

 ______
|      |
| rrr  |
| r r  |
| rrr  |
|      |
 ------



a few layers very very small only give dots:


 ______
|    r |
| r    |
|   r  |
 ------


a layer to the east and one to the north:

 __rr__
|      |
r      |
|      |
 ------


too deep inside of one layer:

 rrrrrr
r      r
r      r
r      r
 rrrrrr


> I have another question: I can see how this would be good for a GIS
> newbie (that would be ... me).  How often does a GIS professional run
> into the "lost layer" problem?  I'm trying to figure out if this is a
> feature that is useful for everyone, or only useful for beginners.
> Useful for beginners is good, but if it's not useful for experts, then
> it's just wasted cycles and a cluttered display.

I guess a GIS professional will run into it less often 
as usually the working area is known well and set up nicely so you
cannot go wrong.

On the other hand, we do want to make this tool easy to use 
as it is targeted as towards occasional users and power users alike.

>  > I think it is a good idea to have such a target tracking mode
>  > in one or the other way. Using a red color in a frame could help us
>  > to signal the other potential situations, too.
>  > Like when you are too much into a layer to actually see a feature,
>  > then the hole frame could be red.
> 
> How about using a set of "location" icons in the layer list, then?

A very good idea, to.

> You could have a square box indicating the view.  You could have a
> squiggle indicating the layer data.  The icons would show where each
> layer data is relative to the view.  Argh, I can't draw this in
> ASCII.  I'll quick whip up a set of pictures:
> 
> http://russnelson.com/thuban-icons/

Nice.

> It would be relatively simple to throw one of these icons into the
> list of layers, indicating the location of the layer extents relative
> to the current view.

Yes it might be less intrusive then the color idea
but also giving less information when you see two layers which are
close to each other.
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