So I dug into components a bit. I found

MouseComponent

but it doesn't appear to be nearly as full-featured as the extensions on View. For example,

override fun onMouseEvent(views: Views, event: MouseEvent) {
        when {
            event.typeClick -> {
                // triggers whether or not mouse is inside view's bounds
                println("CLICKED!")
            }
            event.typeEnter -> {
                // never triggers?
                println("ENTER")
            }
        }
    }

I feel like I'm fighting the engine here, which probably means I'm doing something wrong...