[Qgis-developer] General questions & multiple map canvases

[Radim Blazek]

On 5/15/06, Martin Dobias <wonder.sk at gmail.com> wrote:
> > what about stable release? Don you want to skip 0.8?
> > Could we leave this until 0.8 release? I know that debugging
> > is boring but there is no other way.
>
> As Tim has already explained, all this stuff is post 0.8 release.

Yes, but working on new features reduces sources for stable release.

> Right, layers should be considered as data sources and thus when
> they're being edited it's better to share them to display them in the
> same state for all map canvases. Also we will need a mechanism which
> will try to detect if the same layer is being loaded another time and
> not to create another copy of the data source but to use a copy
> already being used.
>
> > We should separate layer-data and its symbology maybe?
>
> Separating layer data from its symbology seems to be the right
> direction and think of QgsMapLayer as being a only data source,
> providing symbology information to map renderer separately.
>
> > But what about selection set and query?
>
> Where do you see problems in these features? You mean that every map
> canvas should allow select anouther set of features?

No, but selection set must be separated from data source in the same
way as symbology.
The query (permanent SQL condition for one layer) should result in a
new data source?

Radim