Фокус: Tab, стрелки и возврат из меню

using Reckfell;

public partial class FocusMenuDemo : Control
{
    public VBoxContainer Main { get; private set; } = null!;
    public VBoxContainer Details { get; private set; } = null!;
    public Button Start { get; private set; } = null!;
    public Button Options { get; private set; } = null!;
    public Button Close { get; private set; } = null!;
    public Button Back { get; private set; } = null!;
    public int StartCount { get; private set; }
    private Control? _returnFocus;

    public override void _Ready()
    {
        UiSampleStyle.Prepare(this);
        var panel = new PanelContainer(); AddChild(panel);
        panel.SetAnchorsAndOffsetsPreset(LayoutPreset.FullRect, margin: 24);
        Main = new VBoxContainer(); Details = new VBoxContainer { Visible = false };
        panel.AddChild(Main); panel.AddChild(Details);
        Start = Button(Main, UiSampleStyle.Text("Начать", "Start"));
        Options = Button(Main, UiSampleStyle.Text("Настройки", "Settings"));
        Close = Button(Main, UiSampleStyle.Text("Закрыть меню", "Close menu"));
        Button[] buttons = [Start, Options, Close];
        for (int i = 0; i < buttons.Length; i++)
        {
            Button current = buttons[i], next = buttons[(i + 1) % buttons.Length], previous = buttons[(i + buttons.Length - 1) % buttons.Length];
            current.FocusNext = current.GetPathTo(next); current.FocusPrevious = current.GetPathTo(previous);
            current.FocusNeighborBottom = current.GetPathTo(next); current.FocusNeighborTop = current.GetPathTo(previous);
        }
        Details.AddChild(new Label { Text = UiSampleStyle.Text("Экран настроек", "Settings screen") });
        Back = Button(Details, UiSampleStyle.Text("Назад", "Back"));
        Start.Pressed += () => StartCount++; Options.Pressed += OpenDetails;
        Close.Pressed += Hide; Back.Pressed += CloseDetails;
        Callable.From(() => Start.GrabFocus()).CallDeferred();
    }

    private static Button Button(VBoxContainer parent, string text)
    {
        var button = new Button { Text = text, FocusMode = FocusModeEnum.All };
        parent.AddChild(button); return button;
    }

    public void OpenDetails()
    {
        _returnFocus = GetViewport().GuiGetFocusOwner();
        Main.Hide(); Details.Show(); Back.GrabFocus();
    }

    public void CloseDetails()
    {
        Details.Hide(); Main.Show();
        Control target = _returnFocus is Button b && ReckfellObject.IsInstanceValid(b) && b.IsVisibleInTree() && !b.Disabled ? b : Start;
        target.GrabFocus();
    }

    public void ShowMenu() { Show(); if (Details.Visible) Back.GrabFocus(); else Start.GrabFocus(); }

    public override void _UnhandledInput(InputEvent @event)
    {
        if (IsVisibleInTree() && Details.Visible && @event.IsActionPressed("ui_cancel"))
        {
            CloseDetails(); GetViewport().SetInputAsHandled();
        }
        else if (IsVisibleInTree() && @event.IsAction("ui_accept")) GetViewport().SetInputAsHandled();
    }
}