Re: [udig-devel] Does anybody know another Selection Tool than "Box sele

[Gabriel Roldán <groldan@xxxxxxxx>]

Hi Sergiy and Jesse,

sorry for chiming in so late.

Right now, among bbox selection you can "hand select" features by selecting 
rows in the Table View.

As for extra selection tools, from the top of mu head I could think of the 
following alternative selection methods, which guess would be useful as 
selection tools:

- Line selection: select all features that instersect the line drawn by the 
tool
- Polygon selection: same by polygon
- Band selection: asks the user to specify a buffer distance over the line to 
be drawn, and use the resulting polygon as intersection filter
- Circle, draw a circle to be used as intersection filter
- Overlay: opens a dialog to specify selecting all the features of a given 
layer that intersect/touch/disjoint/cross/contains/are within/overlaps the 
(selected?) features of another layer.

And of course an attribute driven selection, which might well be a CQL (Common 
Query Language) editor to specify a selection filter in a SQL'like way.

Ah, and to feel it complete enough, I would add next to the Edit/Clear 
Selection menu option, an option to "Invert selection".

As for how the selections are handled, IMHO once a selection filter is set to 
a layer and it happens no features satisfy the criteria, the layer's 
selection filter should be reset to Filter.NONE, just as if there were no 
filter at all. Rationale is as follow:
- it is very common that a user, clicks on a point where there are no feature 
to clear his current selection. This instead sets a bbox filter which gets 
none.
- If a selection filter which returns no features is set, but the data changes  
at the backend (say features are added outside udig that touch the geometry 
in the selection filter), the next rendering will show up those features as 
selected. It seems more reasonable, again, IMHO, that once a selection is 
made it is not changed but by a user request.
- Selection filters that lead to no features selected may force some logic to 
be more complex than needed, like a spatial operation that works over the 
selected features if there is a selection set, or over the whole layer if 
not. The user may wonder why is he getting a "no selected features" message 
if he explicitly cleared the selection by clicking outside any feature!

My 2c.

Gabriel.

So I would like to propose

On Monday 19 March 2007 20:41:36 Jesse Eichar wrote:
> Could you describe such as tool?  Take me through a use of this tool.
>
> FYI BBox tool can add features to a selection by holding dow shift I
> believe.
>
> Jesse
>
> On 19-Mar-07, at 12:20 PM, Sergiy Doroshenko wrote:
> > Hi!
> >
> > Can you tell me is there another selection tools? And where they
> > can be found.
> >
> > Box selection tool can select only contiguous features. But if there
> > exists some tool, that can select non contiguous features?
> > _______________________________________________
> > User-friendly Desktop Internet GIS (uDig)
> > http://udig.refractions.net
> > http://lists.refractions.net/mailman/listinfo/udig-devel
>
> _______________________________________________
> User-friendly Desktop Internet GIS (uDig)
> http://udig.refractions.net
> http://lists.refractions.net/mailman/listinfo/udig-devel