Unity UI ButtonSmartNav

ButtonSmartNav.cs

using UnityEngine.UI;

// Use this class instead of Unity's default Button
// to automatically skip disabled and inactive Buttons
// if you define your navigation as explicit
public class ButtonSmartNav : Button
{
    bool CanReachSelectable(Selectable select)
    {
        return !select || (select.interactable && select.gameObject.activeInHierarchy);
    }

    public override Selectable FindSelectableOnLeft()
    {
        var cursor = base.FindSelectableOnLeft();
        while (!CanReachSelectable(cursor)) cursor = cursor.FindSelectableOnLeft();
        return cursor;
    }

    public override Selectable FindSelectableOnRight()
    {
        var cursor = base.FindSelectableOnRight();
        while (!CanReachSelectable(cursor)) cursor = cursor.FindSelectableOnRight();
        return cursor;
    }

    public override Selectable FindSelectableOnUp()
    {
        var cursor = base.FindSelectableOnUp();
        while (!CanReachSelectable(cursor)) cursor = cursor.FindSelectableOnUp();
        return cursor;
    }

    public override Selectable FindSelectableOnDown()
    {
        var cursor = base.FindSelectableOnDown();
        while (!CanReachSelectable(cursor)) cursor = cursor.FindSelectableOnDown();
        return cursor;
    }
}