On Montag, 13. April 2020 18:50:17 CEST Kevin Kofler wrote: > Hi, > > I have a question concerning development of plugins for Qt, so hopefully it > is not entirely off-topic here: > > Today, a user on #fedora-kde ran across a crash which resulted from: > * a GTK+/GNOME application (Jami) using (for some reason) QImage to load > images, without a QGuiApplication or QApplication constructed, vs. > * a QImage format plugin (QtPBFImagePlugin) using font APIs that require > QGuiApplication and abort otherwise. > > Obviously, one or the other must be wrong. So, who is to blame? > > There is also an additional issue, in that the plugin's check for supported > images is too broad, which leads to it getting (wrongly) automatically > chosen in the first place and triggering the conflict. We have already > reported that one as a bug, because in that case, it is clear who is at > fault: > https://github.com/tumic0/QtPBFImagePlugin/issues/6 > but I do not know whom to blame for the other issue. > > I have looked at the documentation, but I was not able to find a definite > answer to my question there either. I see that, e.g., > QImageReader::supportedImageFormats() is documented as requiring > QApplication, but I do not know whether that is relevant here. > I think supporting QImage without QGuiApplication is supported but not recommended. We have tests for it in qtbase QTEST_*GUILESS*_MAIN. Not sure it is a documented thing though.
_______________________________________________ Development mailing list [email protected] https://lists.qt-project.org/listinfo/development
