Hi Martin, On 07/01/2019 10:22, Martin Dobias wrote: > Hi Hugo > > Are the issues you mentioned solved now by your PR > https://github.com/qgis/QGIS/pull/8724 or that was some other separate > issue?
Unfortunately, this only solves a very small part of the problem. The overall issue of wrong cache synchronization is still there. > > For your open question with "click first" behavior of vertex tool as > an option - I don't know. There has been some interest to address some > ergonomic issues in the new implementation, but I am not sure yet what > we would end up doing... I understand. I am still looking for a solution here. So instead of resurrecting the old vertex tool, would it be possible to make it work without index/cache ? I understand a cache has been introduced to allow for edition when lots of geometries are displayed on the current extent. But usually geometry editions are made at a high level of details, when a few geometry features are visible. Is a cache still needed if we somehow enforce the edition to be allowed only at small scale ? > > Cheers > Martin > > On Tue, Dec 18, 2018 at 9:30 AM Hugo Mercier <hugo.merc...@oslandia.com> > wrote: >> >> Hi, >> >> I am facing some issues with the vertex tool of 3.x. >> >> In 2.18 the "node tool" was working by clicking first on a geometry to >> select it or its vertices and then displace them. With the new "vertex >> tool", there is no more first click involved and geometries are >> "selected" when the mouse position is close enough. >> >> This behaviour and ergonomic change (which I like !) implied an >> implementation that needs, for descent performances, to build a cache of >> geometries and maintain it. >> >> Problems arise when a modification on a layer may trigger modifications >> on others. For example when two layers have triggers in database (to >> maintain a correct network topology in database for instance), or even >> when the same layer is opened twice. >> >> QGIS has no way to know that the modification of a layer can modify >> another layer. So it easily leads to problems where "phantom" geometries >> are still selectable but actual (modified by side effect) geometries are >> not. >> >> I introduced in a previous version a way to express "data dependencies" >> between layers, with this issue in mind. For PostgreSQL databases, there >> is probably also a way to circumvent this by using the LISTEN/NOTIFY >> mechanism and some lines of Python. >> However I find these solutions very obscure and unfriendly. >> >> Open question: what about re-introducing the old "click first" behaviour >> of the vertex tool (and probably other tools) in a next version ? Not as >> a replacement, but as a possible alternative. >> _______________________________________________ >> QGIS-Developer mailing list >> QGIS-Developer@lists.osgeo.org >> List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer >> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer > _______________________________________________ QGIS-Developer mailing list QGIS-Developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer