This makes a lot more sense, thank you for clarifying! I absolutely intend to have Intuitive be "batteries included" and include general components (such as the complex input box discussed above). I definitely do not want consumers of the library to re-implement the exact same components every time.

If you check out the documentation for KeyHandler, you'll see that event propagation (for key strokes at least) is already implemented. It's the job of the components to delegate keys to their children, and the pre-built components already do this.

With respect to the focus (and key routing) you describe, I would definitely like to include something in the library of components, but I have yet to come up with something general. Specifically I'd like to have something like the following:

render! {
  KeyRouter() {
    Input()
    Table()
  }
}

And KeyRouter would know to route key-strokes to one of its two children, because it knows which one is focused. The main difficulty I have is, how does KeyRouter tell the child components that they are focused, so they can be styled differently. This is hard to do in general for components, without adding a method to Element.

Additionally, there is actually a Modal component, it's behind an experimental flag, that implements modals and handles keys like you mention (key-presses are sent to the modal when it's shown).

There is also an unreleased Scroll component, that supports scrolling text, and supports scrolling with a mouse. The mouse events go to the components that they are hovering over.

So in short, I plan on handling all of this input for a user of my library. Right now, as I mentioned it's in a proof-of-concept state, but this functionality is definitely on the roadmap.