On Tue, Feb 3, 2009 at 10:33 PM, <pcr...@pcreso.com> wrote: > Is it possible to have a second transparent map canvas, analogous to the > Mapinfo cosmetic layer. > > This would allow, for example, a complex background map to remain static so a > gps layer in the new canvas can be quickly refreshed without refreshing the > entire map & all the background layers, unless, of couser, the map extent > changes. > > There are several times I've made simple changes to a small layer & QGIS > takes some time to re-render everything, when 99% of the refresh doesn't > actually change anything. > > This could be accomplished by having two map canvases, so users could add > static layers to the bottom one & more dynamic ones to the top one, to suit > their needs.
This is already possible. But instead of cosmetic layer we talk about canvas items: map canvas contains rendered map and optionally any number of other map canvas items (see QgsMapCanvasItem class). Canvas items can be updated whenever needed and no re-render of map is required. Also rubber band (see QgsRubberBand) which is used for measuring distances and areas is a canvas item. Martin _______________________________________________ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
