[Openev-discuss] Using GIS GvShapeLayers as label layers

[Frank W. <war...@po...>]

Folks, 

As part of ongoing CIETMap work, we need the ability to load a GIS point
layer with labels in attributes, and we want to be able to display them
as labels in CIETMap and I would like to do this the same way in OpenEV. 

The plan is to extend the vector properties panel to include an option for
selecting a field to use for labelling, and to include some attributes for
text such as size, font, and color.   

Internally this will be implemented in a manner related to the OGR Feature
Style specification:
  http://gdal.velocet.ca/projects/opengis/ogr_feature_style_008.html

In particular, I will allow placement of an _gv_ogrfs property in the layer
properties to hold the information on how elements should be drawn.  This
might be something like:

  LABEL(f:"Arial",s:12pt,t:{text_string})

This would indicate that each feature should have a 12pt high Arial label
with the text extracted from the "text_string" property displayed. 

The controls on the property panel will go in a new group box below
the existing three, and if enabled the label will be in addition to drawing
the normal geometry, not instead of.  To disable drawing of the geometry, 
set it's color to transparent.

Any opinions?

Best regards,

---------------------------------------+--------------------------------------
I set the clouds in motion - turn up   | Frank Warmerdam, war...@po...
light and sound - activate the windows | http://pobox.com/~warmerda
and watch the world go round - Rush    | Geospatial Programmer for Rent