[Qgis-user] Let's discuss on a Mask feature

[Alister Hood]

Hi,

> Date: Fri, 7 Dec 2012 13:10:40 +0100
> From: Vincent Picavet <vincent.ml at oslandia.com>
> To: HAUBOURG <regis.haubourg at eau-adour-garonne.fr>
> Cc: "'qgis-user at lists.osgeo.org'" <qgis-user at lists.osgeo.org>
> Subject: Re: [Qgis-user] Let's discuss on a Mask feature
> Message-ID: <201212071310.41007.vincent.ml at oslandia.com>
> Content-Type: Text/Plain;  charset="iso-8859-1"
> 
> 
> Before speaking about performance and technical aspect, we should agree on
> where in QGIS this kind of display-oriented ?layer? should go : composer, some
> kind of modifier layer, overlay layer, or classic data layer, or another better
> solution ?
> We should generalize the problem, find a global concept, and verify that
> masking is covered by it.
> Or is masking the only forseen feature of this kind ?
> 
> What do other think of it ?
> 
> Vincent

There may be some parallel with the discussion earlier in the year about graticules as map/composer decorations versus layers:
http://lists.osgeo.org/pipermail/qgis-developer/2012-May/020040.html
http://lists.osgeo.org/pipermail/qgis-developer/2012-May/020047.html
http://lists.osgeo.org/pipermail/qgis-developer/2012-July/020854.html

For ease of use on a basic level it seems to me that instead of being a separate layer it should be some sort of symbology option tied to the original map layer, similar to how it works in Mapinfo.

If you need a different feature in the layer to act as the mask for each page in an Atlas, I don't know the best way of controlling that, but I think the same problem would need to be solved for other things like map titles.

Alister