[Qgis-user][Qgis-developer] measuring tool

Magnus Homann magnus at homann.se
Wed Jan 17 14:19:03 EST 2007

Micha Silver wrote:
> Just installed 0.8 on windows and it looks friggin terrific!
> Is there still a problem with the measuring tool? (I recall a post a 
> year back about this).
> I am in our local transverse meracator projection (Israel ITM, SRID 
> 2039). THe project is set to that projection and the layers are 
> recognized in the correct projection. But clicking on either  measure 
> button, the warning message comes up regarding "... geographic 
> coordinate system..." and the resulting numbers are way off.

Measure tool basically only works reliably when projection is turned on.
Scale bar and measure tool has different way of considering measuring.

I propose a unified measure model, where MapCanvas contain a QgsMeasure 
object which can be used by both measure tool, scale bar and scale 
indication (at the coorindates). I also propose that "map units" will 
direclty follow by projection. If it's a +proj=longlat (such as 2585) it 
will be shown as degrees. If it's a projected ( +proj=utm, etc) it will 
be in meters (or feet).

The projection used to determine scale/measurement will be project 
projection (if turned on) or active layer(???) if off.

I was goping to have a second look at the problme tonite, but as Micha 
brought it up... :-)

This will in that case be implemented in 0.9 only.

Sorry for the cross-mail. I will be on #qgis of a couple of hours.

Magnus Homann
magnus at homann.se
+46 702 399 558

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