gtk-layer-shell is a library to write GTK applications that
use Layer Shell.
Layer Shell is a Wayland protocol for desktop shell components,
such as panels, notifications and wallpapers. You can use it to anchor
your windows to a corner or edge of the output, or stretch them across
the entire output. It supports all Layer Shell features including popups
and popovers (GTK popups Just Work™). This Library is compatible with
C, C++ and any language that supports GObject introspection files
(Python, Vala, etc,).

This library only works on Wayland, and only on Wayland compositors
that support the Layer Shell protcol. Layer shell is supported on:

•wlroots based compositors (such as Sway)
•Mir-based compositors (some may not enable the protocol by default
and require --add-wayland-extension zwlr_layer_shell_v1)

Layer shell is not supported on:

•Gnome-on-Wayland
•Any X11 desktop