This will be shared by the notifications stored in a wibox/wibar and the
ones using a popup. It extends the constraint and margins container
to take care of some boilerplate code. While other widgets have their
own public API, those 2 are private since they are not different enough
to warrent a new public module.
It is a normal textbox with some extra boilerplate code. Having this
in a separate widget allows the notification to be defined from rc.lua
without a ton of beautiful options and connect_signal.
Emmanuel Lepage Vallee