spectre.console/src/Spectre.Console/Rendering/Traits/Extensions/AlignableExtensions.cs

namespace Spectre.Console
{
    /// <summary>
    /// Contains extension methods for <see cref="IAlignable"/>.
    /// </summary>
    public static class AlignableExtensions
    {
        /// <summary>
        /// Sets the alignment for an <see cref="IAlignable"/> object.
        /// </summary>
        /// <typeparam name="T">The alignable object type.</typeparam>
        /// <param name="obj">The alignable object.</param>
        /// <param name="alignment">The alignment.</param>
        /// <returns>The same instance so that multiple calls can be chained.</returns>
        public static T SetAlignment<T>(this T obj, Justify alignment)
            where T : class, IAlignable
        {
            if (obj is null)
            {
                throw new System.ArgumentNullException(nameof(obj));
            }

            obj.Alignment = alignment;
            return obj;
        }

        /// <summary>
        /// Sets the <see cref="IAlignable"/> object to be left aligned.
        /// </summary>
        /// <typeparam name="T">The alignable type.</typeparam>
        /// <param name="obj">The alignable object.</param>
        /// <returns>The same instance so that multiple calls can be chained.</returns>
        public static T LeftAligned<T>(this T obj)
            where T : class, IAlignable
        {
            if (obj is null)
            {
                throw new System.ArgumentNullException(nameof(obj));
            }

            obj.Alignment = Justify.Left;
            return obj;
        }

        /// <summary>
        /// Sets the <see cref="IAlignable"/> object to be centered.
        /// </summary>
        /// <typeparam name="T">The alignable type.</typeparam>
        /// <param name="obj">The alignable object.</param>
        /// <returns>The same instance so that multiple calls can be chained.</returns>
        public static T Centered<T>(this T obj)
            where T : class, IAlignable
        {
            if (obj is null)
            {
                throw new System.ArgumentNullException(nameof(obj));
            }

            obj.Alignment = Justify.Center;
            return obj;
        }

        /// <summary>
        /// Sets the <see cref="IAlignable"/> object to be right aligned.
        /// </summary>
        /// <typeparam name="T">The alignable type.</typeparam>
        /// <param name="obj">The alignable object.</param>
        /// <returns>The same instance so that multiple calls can be chained.</returns>
        public static T RightAligned<T>(this T obj)
            where T : class, IAlignable
        {
            if (obj is null)
            {
                throw new System.ArgumentNullException(nameof(obj));
            }

            obj.Alignment = Justify.Right;
            return obj;
        }
    }
}