Testing layout changes or experimenting with new layouts is simple due to GLib’s resource overlays. This mechanism allows you to replace or add files to stevia’s build in resource bundle without rebuilding stevia.

Let’s assume you you have the layout’s JSON in the current directory in a file named de.json. You can then use that layout by running:

G_RESOURCE_OVERLAYS=/mobi/phosh/stevia/layouts=$PWD phosh-osk-stevia --replace

This puts all files in the current directory at the resource path /mobi/phosh/stevia/layouts so the layout would appear at /mobi/phosh/stevia/layouts/de.json and thus replace the existing layout there. Adding new layouts for testing works the same way.

If everything works you should see this on the console:

GLib-GIO-Message: Adding GResources overlay '/mobi/phosh/stevia/layouts=/path/to/current/dir'
GLib-GIO-Message: Mapped file '/path/to/current/dir/de.json' as a resource overlay

This informs you that stevia picked up your modified layout (note that /path/to/current/dir/ depends on your current working directory so the output might be slightly different).

If you need to make further changes just stop stevia and run the above command again. This allows for quick test cycles without risking to break your system.