[Qgis-user] More measuring tool questions

[Ron Bentley]

Trying to get a handle on the measuring tool.  My original data is 
geographic coordinates, WGS-84, in a PostGIS database.  "On the fly 
projection" is enabled.  QGIS 1.0.1 on Debian.

I would *like* to display data in geographic coordinates (ie., display 
in lat. and lon.) but measure in feet.  (It's a utility application 
targeted at American linemen.)

I've also created a Python plugin as an alternate measuring tool.  I can 
place a QgsRubberBand and use QgsDistanceArea directly on those coordinates.

When the CRS is geographic coordinates (WGS-84), the default line 
measuring tool returns meters.  My plugin returns degrees.  Both of 
these are regardless of the map unit selected in project properties.

When the CRS is projected, the default line measuring tool still returns 
meters.  My plugin returns distance in the base unit of the projection. 
  Again, both are regardless of the map unit selected.

If the goal is to display in geographic coordinates with measurement in 
feet -- and I'm willing to write a plugin to do it -- is there any way 
to get there short of coding the calculation myself directly from the 
coordinates?

I can pass the whole problem off to PostGIS to do the appropriate 
coordinate conversions and get me the numbers I want if I have to, but 
I'd prefer to avoid that.

Ron Bentley