Add CursorLeft and CursorTop to IConsole

Closes #25

CliFx.Tests/UtilitiesSpecs.cs

@@ -3,11 +3,16 @@ using System.Linq;
 using CliFx.Utilities;
 using FluentAssertions;
 using Xunit;
+using Xunit.Abstractions;
 
 namespace CliFx.Tests
 {
     public class UtilitiesSpecs
     {
+        private readonly ITestOutputHelper _output;
+
+        public UtilitiesSpecs(ITestOutputHelper output) => _output = output;
+
         [Fact]
         public void Progress_ticker_can_be_used_to_report_progress_to_console()
         {
@@ -28,6 +33,8 @@ namespace CliFx.Tests
 
             // Assert
             stdOutData.Should().ContainAll(progressStringValues);
+
+            _output.WriteLine(stdOutData);
         }
 
         [Fact]
@@ -49,6 +56,8 @@ namespace CliFx.Tests
 
             // Assert
             stdOutData.Should().BeEmpty();
+
+            _output.WriteLine(stdOutData);
         }
     }
 }

CliFx/IConsole.cs

@@ -54,6 +54,16 @@ namespace CliFx
         /// </summary>
         void ResetColor();
 
+        /// <summary>
+        /// Cursor left offset.
+        /// </summary>
+        int CursorLeft { get; set; }
+
+        /// <summary>
+        /// Cursor top offset.
+        /// </summary>
+        int CursorTop { get; set; }
+
         /// <summary>
         /// Provides a token that signals when application cancellation is requested.
         /// Subsequent calls return the same token.

CliFx/SystemConsole.cs

@@ -56,6 +56,20 @@ namespace CliFx
         /// <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 GetCancellationToken()
         {

CliFx/Utilities/ProgressTicker.cs

@@ -9,26 +9,29 @@ namespace CliFx.Utilities
     {
         private readonly IConsole _console;
 
-        private string _lastOutput = "";
+        private int? _originalCursorLeft;
+        private int? _originalCursorTop;
 
         /// <summary>
         /// Initializes an instance of <see cref="ProgressTicker"/>.
         /// </summary>
-        public ProgressTicker(IConsole console)
-        {
-            _console = console;
-        }
-
-        private void EraseLastOutput()
-        {
-            for (var i = 0; i < _lastOutput.Length; i++)
-                _console.Output.Write('\b');
-        }
+        public ProgressTicker(IConsole console) => _console = console;
 
         private void RenderProgress(double progress)
         {
-            _lastOutput = progress.ToString("P2", _console.Output.FormatProvider);
-            _console.Output.Write(_lastOutput);
+            if (_originalCursorLeft != null && _originalCursorTop != null)
+            {
+                _console.CursorLeft = _originalCursorLeft.Value;
+                _console.CursorTop = _originalCursorTop.Value;
+            }
+            else
+            {
+                _originalCursorLeft = _console.CursorLeft;
+                _originalCursorTop = _console.CursorTop;
+            }
+
+            var str = progress.ToString("P2", _console.Output.FormatProvider);
+            _console.Output.Write(str);
         }
 
         /// <summary>
@@ -41,7 +44,6 @@ namespace CliFx.Utilities
             // when there's no active console window.
             if (!_console.IsOutputRedirected)
             {
-                EraseLastOutput();
                 RenderProgress(progress);
             }
         }

CliFx/VirtualConsole.cs

@@ -44,6 +44,12 @@ namespace CliFx
             BackgroundColor = ConsoleColor.Black;
         }
 
+        /// <inheritdoc />
+        public int CursorLeft { get; set; }
+
+        /// <inheritdoc />
+        public int CursorTop { get; set; }
+
         /// <inheritdoc />
         public CancellationToken GetCancellationToken() => _cancellationToken;