Hello, Thanks Nyall for your advice.
I have chosen to move the raster layer properties to the gui. As the widget is very convenient, no reason to rebuild my own. Moreover, it appears there is not a lot of code to change. So I purpose this PR: https://github.com/qgis/QGIS/pull/31942 The tests seem to pass for QGIS, and I have tried to import the QgsRasterLayerProperties class to a standalone application only using the gui library, it is ok. Vincent Cloarec www.reos.site Le jeu. 19 sept. 2019 à 00:37, Nyall Dawson <[email protected]> a écrit : > On Thu, 19 Sep 2019 at 13:55, Vincent Cloarec <[email protected]> wrote: > > > > In standalone applications, I am using the QgsRasterLayerProperties > class to manage rasters displayed in the map canvas. > > > > However, since QGis 3.8, this class is no longer independent from the > QgisApp instance because the methode > QgisApp::instance()->askUserForDatumTransform() is called from the > QgsRasterLayerProperties instance. > > > > As in my standalone applications, I don't have QgsApp instance (no > need), now this applications crash when the raster layer properties widget > opens ... > > > > So, after a look at the Qgis code, I am thinking about to make a PR to > make again the QgsRasterLayerProperties independant from the QgisApp > instance. I think it could be possible with a static method in the QgisApp > class. I have to work on it. > > Possibly -- but it's a band-aid solution only. There's a LOT of code > in the app library which will make assumptions that the QgisApp > instance is available, and that's why all this code is partitioned off > into the app library. app also has no stable API guarantees and you'll > continue to hit situations like this. > > I'd suggest two possible alternative ways forward: > > 1. Use the stable api classes exposes through the gui library to > rebuild your own raster layer properties dialog > 2. Submit a PR moving the raster layer properties class from app -> > gui and adding it to the stable API > > Both approaches are more upfront work, but are paths to much less pain > and future breakage... > > Nyall >
_______________________________________________ QGIS-Developer mailing list [email protected] List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
