Merge pull request #1747 from phil-scott-78/spinner-extension

src/Spectre.Console/Extensions/AnsiConsoleExtensions.Async.cs

@@ -0,0 +1,92 @@
+namespace Spectre.Console.Extensions;
+
+/// <summary>
+/// Provides extension methods for running tasks with a spinner animation.
+/// </summary>
+public static class SpinnerExtensions
+{
+    /// <summary>
+    /// Runs a task with a spinner animation.
+    /// </summary>
+    /// <param name="task">The task to run.</param>
+    /// <param name="spinner">The spinner to use.</param>
+    /// <param name="style">The style to apply to the spinner.</param>
+    /// <param name="ansiConsole">The console to write to.</param>
+    /// <returns>The result of the task.</returns>
+    public static async Task Spinner(this Task task, Spinner? spinner = null, Style? style = null, IAnsiConsole? ansiConsole = null)
+    {
+        await SpinnerInternal<object>(task, spinner ?? Console.Spinner.Known.Default, style, ansiConsole);
+    }
+
+    /// <summary>
+    /// Runs a task with a spinner animation.
+    /// </summary>
+    /// <typeparam name="T">The type of the task result.</typeparam>
+    /// <param name="task">The task to run.</param>
+    /// <param name="spinner">The spinner to use.</param>
+    /// <param name="style">The style to apply to the spinner.</param>
+    /// <param name="ansiConsole">The console to write to.</param>
+    /// <returns>The result of the task.</returns>
+    public static async Task<T> Spinner<T>(this Task<T> task, Spinner? spinner = null, Style? style = null, IAnsiConsole? ansiConsole = null)
+    {
+        return (await SpinnerInternal<T>(task, spinner ?? Console.Spinner.Known.Default, 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(AnsiSequences.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(AnsiSequences.CUB(spinnerFrame.Length)));
+            ansiConsole.Cursor.Show();
+            await cancellationTokenSource.CancelAsync();
+        }
+    }
+}

src/Spectre.Console/Internal/Polyfill/CancellationToken.cs

@@ -0,0 +1,13 @@
+#if NETSTANDARD2_0
+namespace Spectre.Console
+{
+    internal static class CancellationTokenHelpers
+    {
+        public static Task CancelAsync(this CancellationTokenSource cts)
+        {
+            cts.Cancel();
+            return Task.CompletedTask;
+        }
+    }
+}
+#endif