[Qgis-developer] TileServer as layer for qgis

Marco Hugentobler marco.hugentobler at karto.baug.ethz.ch
Fri Nov 21 03:08:24 EST 2008

Hi Richard

One way to do it is to create a subclasse of QgsRasterDataProvider, similar to 
how it is done for WMS.

> - is there already some notion in Qgis for 'fixed scales', needed for
> this kind of layers (I think...).

I can see two possibilities here:

- don't fix the scale but do a bit of raster scaling to make the images fit to 
the scale. You'll need to try if the images still look nice with the scaling 
(and we have the possibility to 'zoom to best scale'). 

- Fix the scale. This needs some thinking about how to do it in a sound way. 
Because such maps can also be printed or used in 3rd party apps. It could 
probably be done at level QgsMapRenderer.


On Thursday 20 November 2008 21:36:43 Richard Duivenvoorde wrote:
> Hi All,
> having looked at Kai Winter's very nice QMapControl
> http://medieninf.de/qmapcontrol/, a QtWidget capable of showing maps
> from different Map Tile services (OpenStreetmap, Yahoo, GoogleMaps), I'm
> wondering what is the best way to have this kind of functionality in
> QGis also. Having the possibility to show an openstreetmap as
> background-map for data availabe in Sperical Mercator, would be a very
> nice feature of qgis (for people generating mapimages, not for hardcore
> gismen?).
> I'm aware of Martin's OSM plans, but was not finding it in his plans in
> the short term (http://mapserver.sk/~wonder/swproj/spec.html ??)?
> Questions:
> - what would be the best way to implement this:
> 1) incorporating Kai's QMapControl
> 2) writing it as a Python plugin
> 3) writing it as a c++ layer/plugin
> - is there already some notion in Qgis for 'fixed scales', needed for
> this kind of layers (I think...).
> Because I'm not a cpp-dev I thought to start off with a python plugin,
> but get stuck in finding possibilities for painting a tile on a new
> (raster?) layer.
> Can somebody give me a hint or some information about different
> possibilities? Or what their opinion if for the best strategy to achieve
> this kind of funcionality?
> TIA, Regards,
> Richard Duivenvoorde
> ps my 2 cent's about releasing 1.0.0 or waiting for the labeling stuff,
> I would vote for a release in december
> _______________________________________________
> Qgis-developer mailing list
> Qgis-developer at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/qgis-developer

Dr. Marco Hugentobler
Institute of Cartography
ETH Zurich
Technical Advisor QGIS Project Steering Committee

More information about the Qgis-developer mailing list