Key-event helper for the Harlock.Elements.tabs/1 widget.

The widget is a dumb renderer — the app holds the active tab id in its model. When the tabs element has focus, route key events through apply_key/3 to compute the next active id:

def update({:key, _, _} = event, %{tab: active} = model) do
  case Harlock.Focus.current() do
    :tabs ->
      case Harlock.Tabs.apply_key(event, active, [{:a, "Alpha"}, {:b, "Beta"}]) do
        {:select, id} -> %{model | tab: id}
        :noop -> model
      end

    _ ->
      model
  end
end

Bindings:

• Left / Right — cycle tabs (with wrap)
• Home / End — first / last
• anything else — :noop