SUMMARY kdiff3 has no window or window border on gnome4, wayland, arch linux. so no close button, no resize. it looks like it is in fullscreen mode. pressing f11 to toggle between full screen and not lets kdiff3 appear and disappear, instead of making it full screen and within a window. > paru -Q | grep qt avidemux-qt 2.7.8-2 libdbusmenu-qt5 0.9.3+16.04.20160218-5 polkit-qt5 0.113.0-2 poppler-qt5 21.05.0-1 qt5-base 5.15.2+kde+r192-1 qt5-declarative 5.15.2+kde+r24-1 qt5-graphicaleffects 5.15.2-1 qt5-location 5.15.2-3 qt5-multimedia 5.15.2-1 qt5-quickcontrols 5.15.2-1 qt5-quickcontrols2 5.15.2-1 qt5-sensors 5.15.2-1 qt5-speech 5.15.2-1 qt5-svg 5.15.2+kde+r7-1 qt5-wayland 5.15.2+kde+r19-1 qt5-webchannel 5.15.2-1 qt5-webkit 5.212.0alpha4-10 qt5-x11extras 5.15.2-1 qt5ct 1.2-1
this is valid for kdiff3-1.9.2 as well
Based on gnome response to this issue I am declaring gnome+wayland an unsupported configuration.
Created attachment 138713 [details] Screenshot FWIW this is what kdiff3 looks like on Fedora 33 Gnome Wayland. There is a title bar, close button and the window is resizable, so the lack of xdg-decoration support is not necessarily a problem
Still I have no good-way to control that behavior. How is Fedora doing it?
That's because Fedora Workstation uses QGnomePlatform, which configures Qt to draw the correct window decoration on GNOME. Most distributions do not have QGnomePlatform with GNOME by default.
Cf. https://github.com/FedoraQt/QGnomePlatform
Created attachment 138715 [details] Screenshot without QGnomePlatform Even without QGnomePlatform there still is a proper window decoration
Yes, that's Qt's built-in fallback decoration. However, that implementation is somewhat buggy, as far as I know.
Sounds like a distro issue in that case. Anyway to detect QGnomePlatform from CMake?
You could look for the existence of "/usr/lib64/qt5/plugins/wayland-decoration-client/libqgnomeplatformdecoration.so"
@soluturn, please include the output of "env".
>Anyway to detect QGnomePlatform from CMake? We don't want or need to do that.
In case that wasn't clear, QGnomePlatform is not the problem, if anything it's the solution. Qt has support for client side decoration built in, via a plugin mechanism. QGnomePlatform provides such a plugin
Qt loads the decoration plugins from /usr/lib/qt/plugins/wayland-decoration-client qt5-wayland provides libbradient.so which creates the decoration from my second screenshot
Eventually, someone will probably want to make a libdecor[1] plugin for QtWayland. But unfortunately, libdecor hasn't had a release yet. [1]: https://gitlab.gnome.org/jadahl/libdecoration
Dear Bug Submitter, This bug has been in NEEDSINFO status with no change for at least 15 days. Please provide the requested information as soon as possible and set the bug status as REPORTED. Due to regular bug tracker maintenance, if the bug is still in NEEDSINFO status with no change in 30 days the bug will be closed as RESOLVED > WORKSFORME due to lack of needed information. For more information about our bug triaging procedures please read the wiki located here: https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging If you have already provided the requested information, please mark the bug as REPORTED so that the KDE team knows that the bug is ready to be confirmed. Thank you for helping us make KDE software even better for everyone!
This bug has been in NEEDSINFO status with no change for at least 30 days. The bug is now closed as RESOLVED > WORKSFORME due to lack of needed information. For more information about our bug triaging procedures please read the wiki located here: https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging Thank you for helping us make KDE software even better for everyone!
arch linux provides libbradient with qt6: https://archlinux.org/packages/extra/x86_64/qt6-wayland/files/ usr/lib/qt6/plugins/wayland-decoration-client/libbradient.so
arch linux provides libbradient also with qt5-wayland, i see. i did not understand what is necessary to activate it? you mean to use qgnomeplatform @nicolas fella? https://archlinux.org/packages/extra/x86_64/qt5-wayland/
If your looking for help setting up QGnomePlatform or anyother compositor please contact your distro. KDE and kdif3 mantainers can not do anything else to address this issue. Please don't reopen it again.
The official recommendation at this time is to install QGnomePlatform as it is known to work. qgnomeplatform looks like the right package name.