The GTK3-adventure example branch doesn't work with OSK

canonical / iot-example-graphical-snap

Developer Guide for Embedding IoT GUI with Ubuntu Frame

MIT License

22 stars 11 forks source link

The GTK3-adventure example branch doesn't work with OSK #1

Closed AlanGriffiths closed 2 years ago

AlanGriffiths commented 2 years ago

This example uses xfce4-terminal to show the colossal-cave text adventure.

I was expecting this to "just work" with Ubuntu Frame OSK, as xfce4-terminal works with the OSK when run outside a snap environment. But the OSK doesn't show.

I shared these logs with @wmww who said:

wayland-native.log wayland-snapped.log

The good one is binding to the zwp_text_input_manager_v3 global, the bad one is seeing it but the app isn't binding. I strongly suspect different version of GTK or the terminal are in use, but I suppose there could also be some environment variable/config option I don't know about.

However, this seems to be entirely down to the snap environment: after copying the environment variables from the snap and running the snapped binaries directly the OSK appears. Running devmode doesn't help: the snapped version still doesn't show the OSK.

(That probably only leaves something in the layout that differs. But what...)

AlanGriffiths commented 2 years ago

This isn't just xfce4-terminal - I tried a simplified snap with gedit and that too fails to work with the OSK. So there's something GTK related going on.

(As a sanity check, wpe-webkit-mir-kiosk does work with the OSK)

AlanGriffiths commented 2 years ago

Useful data point: the store "gedit" snap does work with OSK.

...

And the magic is somewhere in extensions: [gnome-3-38]

wmww commented 2 years ago

I think the problem is that it's not loading the Wayland IM module. this is approximately what we need, and a lot of the relevant GTK documentation is here. Playing around with it in a non-snap environment, it's quite finicky, but can be made to work.

wmww commented 2 years ago

I poked at it more and what I came up with is:

Run gtk-query-immodules-3.0 with GTK_PATH set to the GTK's library directory (ex /usr/local/lib/x86_64-linux-gnu/gtk-3.0/) and redirect it's output to any file (typically named immodules.cache)
At runtime, have GTK_IM_MODULE_FILE be the path to the immodules.cache file
The contents of immodules.cache (which are conveniently text) need to refer to the correct locations. That means you can either ship gtk-query-immodules-3.0 and run it on the user's machine, bind mount the im modules directory in the snap so it's in the same place at build time and runtime or patch immodules.cache

AlanGriffiths commented 2 years ago

Thanks