Thanks for the explanation. Keeping reference to the object returned by canvas.mapRenderer() helps.
Are you going to fix those problems? Note: in my case, the error happens on QGIS 2.0.1 64 (Qt 4.8.5) / Win7 64 bit but it is working on QGIS 2.0.1 32 (Qt 4.7.1) / Win7 64 and XP 32, but that only question of more frequent garbage collector, I think. Radim On Wed, Dec 18, 2013 at 5:27 AM, Martin Dobias <[email protected]> wrote: > Hi Radim > > I have encountered this problem recently by chance when working on > multi-threaded rendering. In SIP file for QgsMapCanvas, the > mapRenderer() has /Transfer/ annotation (see commit 0246816e). The > annotation has been obviously added to fix some other problem with > "canvas.mapRenderer().hasCrsTransformEnabled()" idiom. I think the > root of all evil is the fact that "hasCrsTransformEnabled" is both a > signal (with one argument) and an ordinary function (no arguments). My > guess is that SIP probably interprets that combination wrong, it seems > that this is not a problem with other functions/signals. > > In any case, /Transfer/ annotation does not seem right. Maybe > /KeepReference/ function annotation would solve the problem (I assume > the python wrapper was getting destroyed too early). Also, having a > signal and a normal function with the same name also does not feel > right - but I guess we need to live with it until 3.0. > > Regards > Martin > > > On Tue, Dec 17, 2013 at 3:28 PM, Radim Blazek <[email protected]> wrote: >> I have got strange bug report for python plugin, when calling from initGui() >> iface.mapCanvas().mapRenderer().hasCrsTransformEnabled() >> it gives >> RuntimeError: wrapped C/C++ object of type QgsMapRenderer has been deleted >> >> From C++ code I see that QgisApp mMapCanvas is created in QgisApp >> constructor and never deleted and QgsMapCanvas mMapRenderer is created >> in QgsMapCanvas constructor and deleted in QgsMapCanvas destructor. I >> don't see how it can happen that QgsMapRenderer is deleted. >> >> Any clue? >> >> Radim >> _______________________________________________ >> Qgis-developer mailing list >> [email protected] >> http://lists.osgeo.org/mailman/listinfo/qgis-developer _______________________________________________ Qgis-developer mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-developer
