The gnome-3-28 extension

galgalesh · October 1, 2019, 2:14pm

This extension helps you snap desktop applications that use GTK 3, GNOME 3.28 and/or GLib.

How to use it

Add extensions: [ gnome-3-28 ] to the application definition in your snapcraft.yaml file. See GTK3 applications for a complete tutorial on how to use this extension.

apps:
  foliate:
    command: usr/bin/com.github.johnfactotum.Foliate
    extensions: [gnome-3-28]
    ...

When to use it

Although this extensions adds support for the GTK 3 runtime, it also includes base desktop technologies such as GLib and cursor themes, so it is useful to almost any desktop application which does not have a more specialized extension available.

Some examples:

GTK3 applications
Java Swing applications, except when they use GTK+ 2 integration.
Games

This extension will not work for GTK+ 2 applications and 32-bit applications.

See Desktop Applications for more information on how to snap a desktop application.

What it does

It ensures the GTK3 and GNOME libraries are available to all parts at build and run time.
It initialises GTK3 and the desktop environment before your application starts so functionality like fonts, themes and a11y works correctly.

To do this, it connects each application to the following content snaps at run time.

gtk-common-themes for common GTK, icon, cursor and sound themes.
gnome-3-28-1804 for the GNOME runtime libraries and utilities corresponding to 3.28.

It also configures each application entry with these additional plugs:

Snapcraft extensions enable snap developers to easily incorporate a set of common requirements into a snap. See Snapcraft extensions for further details.