Spectre.Console Spinner

spectre.inlinespinner.cs

internal static class SpinnerExtensions
{
    public static async Task Spinner(this Task task, Spinner spinner, Style? style = null, IAnsiConsole? ansiConsole = null)
    {
        await SpinnerInternal<object>(task, spinner, style, ansiConsole);
    }

    public static async Task<T> Spinner<T>(this Task<T> task, Spinner spinner, Style? style = null, IAnsiConsole? ansiConsole = null)
    {
        return (await SpinnerInternal<T>(task, spinner, style, ansiConsole))!;
    }

    private static async Task<T?> SpinnerInternal<T>(Task task, Spinner spinner, Style? style = null, IAnsiConsole? ansiConsole = null)
    {
        ansiConsole ??= AnsiConsole.Console;
        
        style ??= Style.Plain;
        var currentFrame = 0;
        var cancellationTokenSource = new CancellationTokenSource();


        // Start spinner animation in background
        var spinnerTask = Task.Run(async () =>
        {
            while (!cancellationTokenSource.Token.IsCancellationRequested)
            {
                ansiConsole.Cursor.Show(false);
                
                var spinnerFrame = spinner.Frames[currentFrame];
                
                // Write the spinner frame
                ansiConsole.Write(new Text(spinnerFrame, style));
                ansiConsole.Write(new ControlCode(CUB(spinnerFrame.Length)));
                
                
                currentFrame = (currentFrame + 1) % spinner.Frames.Count;
                await Task.Delay(spinner.Interval, cancellationTokenSource.Token);
            }
        }, cancellationTokenSource.Token);

        try
        {
            // Wait for the actual task to complete
            if (task is Task<T> taskWithResult)
            {
                var result = await taskWithResult;
                await cancellationTokenSource.CancelAsync();
                await spinnerTask.ContinueWith(_ => { }, TaskContinuationOptions.OnlyOnCanceled);
                
                return result;
            }
            else
            {
                await task;
                await cancellationTokenSource.CancelAsync();
                await spinnerTask.ContinueWith(_ => { }, TaskContinuationOptions.OnlyOnCanceled);

                return default;
            }
        }
        finally
        {
            var spinnerFrame = spinner.Frames[currentFrame];

            ansiConsole.Write(new string(' ', spinnerFrame.Length));
            ansiConsole.Write(new ControlCode(CUB(spinnerFrame.Length)));
            ansiConsole.Cursor.Show();
            await cancellationTokenSource.CancelAsync();
        }
    }


    
    /// <summary>
    /// This control function moves the cursor to the left by a specified number of columns.
    /// The cursor stops at the left border of the page.
    /// </summary>
    /// <remarks>
    /// See <see href="https://vt100.net/docs/vt510-rm/CUB.html"/>.
    /// </remarks>
    /// <param name="steps">The number of steps to move backward.</param>
    /// <returns>The ANSI escape code.</returns>
    // ReSharper disable once InconsistentNaming
    private static string CUB(int steps) => $"\e[{steps}D";
}

use it like so

AnsiConsole.MarkupInterpolated($"  {r.GetType().Name}: ");
await r.Run(model, parameters).Spinner(Spinner.Known.Dots2, new Style(Color.Yellow));
AnsiConsole.MarkupLineInterpolated($"[green]Ok[/]");