Refactor (#94)

CliFx/Infrastructure/SystemConsole.cs

@@ -0,0 +1,103 @@
+using System;
+using System.Threading;
+
+namespace CliFx.Infrastructure
+{
+    /// <summary>
+    /// Implementation of <see cref="IConsole"/> that represents the real system console.
+    /// </summary>
+    public class SystemConsole : IConsole, IDisposable
+    {
+        private CancellationTokenSource? _cancellationTokenSource;
+
+        /// <inheritdoc />
+        public ConsoleReader Input { get; }
+
+        /// <inheritdoc />
+        public bool IsInputRedirected => Console.IsInputRedirected;
+
+        /// <inheritdoc />
+        public ConsoleWriter Output { get; }
+
+        /// <inheritdoc />
+        public bool IsOutputRedirected => Console.IsOutputRedirected;
+
+        /// <inheritdoc />
+        public ConsoleWriter Error { get; }
+
+        /// <inheritdoc />
+        public bool IsErrorRedirected => Console.IsErrorRedirected;
+
+        /// <inheritdoc />
+        public ConsoleColor ForegroundColor
+        {
+            get => Console.ForegroundColor;
+            set => Console.ForegroundColor = value;
+        }
+
+        /// <inheritdoc />
+        public ConsoleColor BackgroundColor
+        {
+            get => Console.BackgroundColor;
+            set => Console.BackgroundColor = value;
+        }
+
+        /// <summary>
+        /// Initializes an instance of <see cref="SystemConsole"/>.
+        /// </summary>
+        public SystemConsole()
+        {
+            Input = ConsoleReader.Create(this, Console.OpenStandardInput());
+            Output = ConsoleWriter.Create(this, Console.OpenStandardOutput());
+            Error = ConsoleWriter.Create(this, Console.OpenStandardError());
+        }
+
+        /// <inheritdoc />
+        public void ResetColor() => Console.ResetColor();
+
+        /// <inheritdoc />
+        public int CursorLeft
+        {
+            get => Console.CursorLeft;
+            set => Console.CursorLeft = value;
+        }
+
+        /// <inheritdoc />
+        public int CursorTop
+        {
+            get => Console.CursorTop;
+            set => Console.CursorTop = value;
+        }
+
+        /// <inheritdoc />
+        public CancellationToken RegisterCancellationHandler()
+        {
+            if (_cancellationTokenSource is not null)
+                return _cancellationTokenSource.Token;
+
+            var cts = new CancellationTokenSource();
+
+            Console.CancelKeyPress += (_, args) =>
+            {
+                // Don't delay cancellation more than once
+                if (!cts.IsCancellationRequested)
+                {
+                    args.Cancel = true;
+                    cts.Cancel();
+                }
+            };
+
+            return (_cancellationTokenSource = cts).Token;
+        }
+
+        /// <inheritdoc />
+        public void Dispose()
+        {
+            _cancellationTokenSource?.Dispose();
+
+            Input.Dispose();
+            Output.Dispose();
+            Error.Dispose();
+        }
+    }
+}