[GRASS-dev] wxGUI/vdigit: add centroid

[Moritz Lennert]

On 14/02/09 14:44, Martin Landa wrote:
> Hi,
> 
> wxvdigit allows in trunk (r35872) and devbr6 (r35873) to add
> automatically centroid to valid areas. You can set this functionality
> in the settings - 'Attributes' -> 'Digitize new area'.
> 
> * add centroid to left/right area
> 
> When new boundary is added, left/right area is checked. In the case
> that area is valid (closed) and has no centroid, new centroid is
> added.
> 
> * do not attach category to boundary
> 
> When digitizing new boundary, category is attached only to the newly
> added centroid.
> 
> Testing welcomed.

Seems to work alright, although I do find this potentially dangereous as 
users might not really understand what they are doing... (but I am 
conscious of the fact that this functionality is what most people would 
expect...) At least, I think that "do not attach category to boundary" 
should be the default when "add centroid to left/right area" is set. 
Actually, I think it should always be the default and that if a user 
want categories for boundaries she should set it explicitely.

A few +/- related remarks:

- Could manual entry of category number be part of the pop-up window 
that shows up when you finish digitizing a feature. Having to go back 
into the paramters window for changing the category for every feature is 
very cumbersome.

- Trying to digitize a polygon which uses one boundary of another, 
existing polygon, I understand that I need to add new vertices to the 
existing polygon at the places where the new polygon boundaries touch 
the existing one. However, whatever I try, I cannot add new vertices. 
When I select the tool and click on a boundary I see a red cross at the 
place I clicked, but I cannot get it to stay.

Moritz