Running GTK applications under Wayland is also possible. However the current Weston version in Yocto 2.4 Rocko is 1.11.1, and GTK is version 3.22.17. Unfortunately only Weston 1.12 includes support for the xdg-shell-v6 protocol, which is required to run GTK 3.22 applications using Wayland compositor.
If we try to run a GTK 3.22 application on Weston 1.11.1, we see this error on launch:
Gdk-WARNING **: wayland compositor does not support xdg_shell interface, not using Wayland display.
This is a known bug; see https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=842001.
Gdk-WARNING **: wayland compositor does not support xdg_shell interface, not using Wayland display.
This is a known bug; see https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=842001.
Building XWayland instead, as explained before, we can use the same GTK hello world example from the Using the X Windows system recipe and run it just by adding the application to the image with the following line added to the conf/local.conf file:
IMAGE_INSTALL_append = " gtk-helloworld"
Then, we can build and program the core-image-weston image as explained before. We can then launch the application by running:
# export XDG_RUNTIME_DIR=/var/run/user/root
# helloworld