Live/pub-sub/reactive capabilities (input & other events, widget reactions, layout reactions)

How would *thyme* solve the example described in https://github.com/vlang/ui/issues/7#issuecomment-576256637 and [clarification](https://github.com/vlang/ui/issues/7#issuecomment-576666180 )?

There is no established terminology for this IIRC, so I call it live variables or it can be viewed as reliable pub-sub mechanism or as reactors or reactivity or as "streaming data API" etc. The point is to express with the lowest possible number of SLOC that two or more distinct widget instances (each of different kind of widget and in a completely different unrelated part of the app) should get the same input event instance (kbd, mouse, IPC, ... - e.g. significant layout change as linked above) and if the widget is not "read only" (e.g. label is read only, but a button with picture/label is both read & write), then the widget instance shall also at the same time have the capability to create any number of new event instances of any kind and anyone interested in this event (i.e. "subscribed") must guaranteed receive it. This everything with defaults so well handled that most common use cases (let's define this to be equivalent to 7GUIs) shall have the very minimum of SLOC (of Rust and YAML) possible.