class MessageView(val author: String, val text: String) : View() {

label(author) {
    style {
        fontWeight = FontWeight.EXTRA_BOLD
    }
}

style { 
    fontWeight = FontWeight.EXTRA_BOLD
    fontFamily = "Comic Sans MS"
}

override val root = vbox { 
    textfield { 
        style { 
            fitToParentWidth()
        }
        action {
            client.sendMessage(text)
            selectAll()
        }
    }

    scrollpane { 
        // add MessageView here
    }
}

root += …

add(MessageView::class)

scrollpane {
    add(MessaveView::class)
}

client.onTextMessage = { who, content, _ ->
    runLater {
        root += MessageView(who, content)
    }
}