On Wed, Apr 16, 2014 at 1:49 PM, Hugo Mercier <hugo.merc...@oslandia.com> wrote: >> On Tue, Apr 15, 2014 at 3:07 PM, Hugo Mercier <hugo.merc...@oslandia.com> >> wrote: >>> >>> The UI asks for numeric levels, but, if I am correct, only relative >>> orders between two symbol layers are important. >>> Was there something else originally planned ? Something like a global >>> level to be able to order symbol layers of different vector layers ? >> >> No, it was meant just for levels within one layer. > > Ok, so ... why the UI asks the user for integers ? And what is the > meaning of two layers with the same number ?
Integers are there for convenience... with more complex scenarios (e.g. roads with highway crossings) it may be handy to have numbers instead of just a pure list, and to possibly have "holes" between the levels. > What about a UI with the list of symbol layers and some up/down buttons ? That would be possible, but maybe harder to use. In the table view, you can see symbols and their levels at once. In a simple list with up/down buttons you need to split the symbols into symbol layers and it is more difficult to identify what are the levels for one symbol (IMHO). >>> Another point : apart from performance issue, I cannot see any reason >>> why *not* to enable symbol levels. Are there situations were users do >>> want different symbol layers to overlap ? >> >> I think there are such situations, from the top of my head: >> - with symbol levels you cannot see the rendering progress (everything >> is rendered at the end) - this makes quite a difference with big >> layers > > If I am correct, you can still see the progress. You will see the first > symbol layer, then the second one, etc. Yes, but only once all features have been fetched from the provider - and that interval usually dominates the rendering time. So, with a layer that takes 5 seconds to render, there will be maybe 4 seconds when you see nothing from the layer. Regards Martin _______________________________________________ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer