I'm very interested in user-definable grid functionality, and I was planning on implementing something myself for a plugin I'm writing. My needs are to have the grid set to an arbitrary angle, and ideally to know which grid square the user has clicked in, relative to a user-defined origin.
If anyone wants to collaborate, or just has ideas on how best to implement it, let me know. Regards, JD On 10 May 2012 05:35, Alister Hood <alister.h...@synergine.com> wrote: >> Date: Wed, 9 May 2012 18:00:07 -0300 >> From: Etienne Tourigny <etourigny....@gmail.com> >> Subject: [Qgis-developer] show grid on map canvas (similiar to grid >> used in composer) - strategy? >> To: qgis-developer <qgis-developer@lists.osgeo.org> >> Message-ID: >> <ca+txyvpd-5vhoycx4uhio9x416hkx9zgeq5ennnqvadp0l9...@mail.gmail.com> >> Content-Type: text/plain; charset=ISO-8859-1 >> >> Hi all, >> >> I would like to add support to draw a grid on the map canvas, in a way >> similar to what is done in the map composer (although perhaps without >> the annotations on the borders). >> >> What should be the approach used? >> >> 1) plugin or core? >> 2) rubberbands or basic plot functions triggered after mapCanvas update? >> >> I think both drawing strategies are possible using a plugin. >> >> It would be best to write in the core, assuming there is sufficient >> interest in this, but it will take time to trickle down to the stable >> version (an argument for making it a plugin). >> >> I know the current workaround is to create a vector grid with ftools, >> but that is a little clunky. >> >> Any thoughts? >> Etienne > > Hi, > I'm not a developer, so this might be a crazy and unnecessary idea, but would > it be feasible to create a graticule _provider_? > > This approach would mean that like grids created with ftools, the grid would > be created as a layer, but it wouldn't be file based and its extents would > automatically update. > > Unlike the approach used in the composer, this would mean: > - digitising tools could snap to the grid lines. > - the identify tool could identify the grid lines. > - the layer could be used for analysis (e.g. you might want to use it to > split vector layers). > - symbology and feature labelling could work just like other vector layers. > > If this was to actually replace the grids in the composer, some improvements > to feature labelling would be needed. Some of these would probably be good > to have anyway, e.g. an option to label both ends of a line, and an option to > align labels horizontally or vertically on the page, rather than N-S or E-W. > I guess the difficult one would be providing a way to display labels outside > the map frame... > > Regards, > Alister_______________________________________________ > Qgis-developer mailing list > Qgis-developer@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/qgis-developer -- One of the advantages of being disorderly is that one is constantly making exciting discoveries. - AA Milne _______________________________________________ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
