Add support for exclusive mode

docs/input/live/index.cshtml

@@ -0,0 +1,12 @@
+Title: Live Displays
+Order: 4
+---
+
+<h1>Sections</h1>
+
+<ul>
+@foreach (IDocument child in OutputPages.GetChildrenOf(Document))
+{
+  <li>@Html.DocumentLink(child)</li>
+}
+</ul>

docs/input/live/progress.md

@@ -1,16 +1,23 @@
 Title: Progress
 Order: 5
+RedirectFrom: progress
 ---
 
 Spectre.Console can display information about long running tasks in the console. 
 
-<img src="assets/images/progress.png" style="max-width: 100%;margin-bottom:20px;">
+<img src="../assets/images/progress.png" style="max-width: 100%;margin-bottom:20px;">
+
+<div class="alert alert-warning" role="alert">
+  <i class="fas fa-exclamation-triangle icon-web"></i> The progress display is not 
+  thread safe, and using it together with other interactive components such as 
+  prompts, status displays or other progress displays are not supported.
+</div>
 
 If the current terminal isn't considered "interactive", such as when running 
 in a continuous integration system, or the terminal can't display 
 ANSI control sequence, any progress will be displayed in a simpler way.
 
-<img src="assets/images/progress_fallback.png" style="max-width: 100%;">
+<img src="../assets/images/progress_fallback.png" style="max-width: 100%;">
 
 # Usage
 

docs/input/live/status.md

@@ -1,10 +1,17 @@
 Title: Status
 Order: 6
+RedirectFrom: status
 ---
 
 Spectre.Console can display information about long running tasks in the console. 
 
-<img src="assets/images/status.gif" style="max-width: 100%;margin-bottom:20px;">
+<img src="../assets/images/status.gif" style="max-width: 100%;margin-bottom:20px;">
+
+<div class="alert alert-warning" role="alert">
+  <i class="fas fa-exclamation-triangle icon-web"></i> The status display is not 
+  thread safe, and using it together with other interactive components such as 
+  prompts, progress displays or other status displays are not supported.
+</div>
 
 If the current terminal isn't considered "interactive", such as when running 
 in a continuous integration system, or the terminal can't display 

docs/input/prompts/multiselection.md

@@ -7,6 +7,11 @@ one or many items from a provided list.
 
 <img src="../assets/images/multiselection.gif" style="width: 100%;" />
 
+<div class="alert alert-warning" role="alert" style="margin-top:20px;">
+  <i class="fas fa-exclamation-triangle icon-web"></i> The use of prompts 
+  insides status or progress displays is not supported.
+</div>
+
 # Usage
 
 ```csharp

docs/input/prompts/selection.md

@@ -7,6 +7,11 @@ a single item from a provided list.
 
 <img src="../assets/images/selection.gif" style="width: 100%;" />
 
+<div class="alert alert-warning" role="alert" style="margin-top:20px;">
+  <i class="fas fa-exclamation-triangle icon-web"></i> Using prompts inside 
+  status or progress displays, are not supported.
+</div>
+
 # Usage
 
 ```csharp

docs/input/prompts/text.md

@@ -1,4 +1,4 @@
-Title: Text
+Title: Text prompt
 Order: 0
 RedirectFrom: prompt
 ---
@@ -6,6 +6,11 @@ RedirectFrom: prompt
 Sometimes you want to get some input from the user, and for this
 you can use the `Prompt<TResult>`.
 
+<div class="alert alert-warning" role="alert">
+  <i class="fas fa-exclamation-triangle icon-web"></i> The use of prompts 
+  insides status or progress displays is not supported.
+</div>
+
 # Confirmation
 
 ```csharp

dotnet-tools.json

@@ -3,7 +3,7 @@
   "isRoot": true,
   "tools": {
     "cake.tool": {
-      "version": "1.0.0-rc0002",
+      "version": "1.1.0",
       "commands": [
         "dotnet-cake"
       ]

examples/Console/Prompt/Program.cs

@@ -59,6 +59,7 @@ namespace Cursor
                 new MultiSelectionPrompt<string>()
                     .PageSize(10)
                     .Title("What are your [green]favorite fruits[/]?")
+                    .MoreChoicesText("[grey](Move up and down to reveal more fruits)[/]")
                     .InstructionsText("[grey](Press [blue]<space>[/] to toggle a fruit, [green]<enter>[/] to accept)[/]")
                     .AddChoices(new[]
                     {
@@ -75,6 +76,7 @@ namespace Cursor
                 fruit = AnsiConsole.Prompt(
                     new SelectionPrompt<string>()
                         .Title("Ok, but if you could only choose [green]one[/]?")
+                        .MoreChoicesText("[grey](Move up and down to reveal more fruits)[/]")
                         .AddChoices(favorites));
             }
 

src/Spectre.Console.Testing/Fakes/FakeAnsiConsole.cs

@@ -9,12 +9,14 @@ namespace Spectre.Console.Testing
     {
         private readonly StringWriter _writer;
         private readonly IAnsiConsole _console;
+        private readonly FakeExclusivityMode _exclusivityLock;
 
         public string Output => _writer.ToString();
 
         public Profile Profile => _console.Profile;
         public IAnsiConsoleCursor Cursor => _console.Cursor;
         public FakeConsoleInput Input { get; }
+        public IExclusivityMode ExclusivityMode => _exclusivityLock;
         public RenderPipeline Pipeline => _console.Pipeline;
 
         IAnsiConsoleInput IAnsiConsole.Input => Input;
@@ -24,6 +26,7 @@ namespace Spectre.Console.Testing
             AnsiSupport ansi = AnsiSupport.Yes,
             int width = 80)
         {
+            _exclusivityLock = new FakeExclusivityMode();
             _writer = new StringWriter();
 
             var factory = new AnsiConsoleFactory();

src/Spectre.Console.Testing/Fakes/FakeConsole.cs

@@ -12,6 +12,7 @@ namespace Spectre.Console.Testing
         public Profile Profile { get; }
         public IAnsiConsoleCursor Cursor => new FakeAnsiConsoleCursor();
         IAnsiConsoleInput IAnsiConsole.Input => Input;
+        public IExclusivityMode ExclusivityMode { get; }
         public RenderPipeline Pipeline { get; }
 
         public FakeConsoleInput Input { get; }
@@ -24,6 +25,7 @@ namespace Spectre.Console.Testing
             bool legacyConsole = false, bool interactive = true)
         {
             Input = new FakeConsoleInput();
+            ExclusivityMode = new FakeExclusivityMode();
             Pipeline = new RenderPipeline();
 
             Profile = new Profile(new StringWriter(), encoding ?? Encoding.UTF8);

src/Spectre.Console.Testing/Fakes/FakeExclusivityMode.cs

@@ -0,0 +1,18 @@
+using System;
+using System.Threading.Tasks;
+
+namespace Spectre.Console.Testing
+{
+    public sealed class FakeExclusivityMode : IExclusivityMode
+    {
+        public T Run<T>(Func<T> func)
+        {
+            return func();
+        }
+
+        public async Task<T> Run<T>(Func<Task<T>> func)
+        {
+            return await func();
+        }
+    }
+}

src/Spectre.Console/AnsiConsoleFactory.cs

@@ -2,6 +2,7 @@ using System;
 using System.Runtime.InteropServices;
 using System.Text;
 using Spectre.Console.Enrichment;
+using Spectre.Console.Internal;
 
 namespace Spectre.Console
 {
@@ -58,7 +59,9 @@ namespace Spectre.Console
                 settings.Enrichment,
                 settings.EnvironmentVariables);
 
-            return new AnsiConsoleFacade(profile);
+            return new AnsiConsoleFacade(
+                profile,
+                settings.ExclusivityMode ?? new DefaultExclusivityMode());
         }
 
         private static (bool Ansi, bool Legacy) DetectAnsi(AnsiConsoleSettings settings, System.IO.TextWriter buffer)

src/Spectre.Console/AnsiConsoleSettings.cs

@@ -30,6 +30,11 @@ namespace Spectre.Console
         /// </summary>
         public InteractionSupport Interactive { get; set; }
 
+        /// <summary>
+        /// Gets or sets the exclusivity mode.
+        /// </summary>
+        public IExclusivityMode? ExclusivityMode { get; set; }
+
         /// <summary>
         /// Gets or sets the profile enrichments settings.
         /// </summary>

src/Spectre.Console/Cli/FlagValue.cs

@@ -31,7 +31,9 @@ namespace Spectre.Console.Cli
             set
             {
 #pragma warning disable CS8601 // Possible null reference assignment.
+#pragma warning disable CS8600 // Converting null literal or possible null value to non-nullable type.
                 Value = (T)value;
+#pragma warning restore CS8600 // Converting null literal or possible null value to non-nullable type.
 #pragma warning restore CS8601 // Possible null reference assignment.
             }
         }

src/Spectre.Console/Cli/Internal/Collections/MultiMap.cs

@@ -165,7 +165,9 @@ namespace Spectre.Console.Cli
             if (pair.Key != null)
             {
 #pragma warning disable CS8604 // Possible null reference argument of value.
+#pragma warning disable CS8600 // Converting null literal or possible null value to non-nullable type.
                 Add((TKey)pair.Key, (TValue)pair.Value);
+#pragma warning restore CS8600 // Converting null literal or possible null value to non-nullable type.
 #pragma warning restore CS8604 // Possible null reference argument of value.
             }
         }

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

@@ -0,0 +1,35 @@
+using System;
+using System.Threading.Tasks;
+
+namespace Spectre.Console
+{
+    /// <summary>
+    /// Contains extension methods for <see cref="IAnsiConsole"/>.
+    /// </summary>
+    public static partial class AnsiConsoleExtensions
+    {
+        /// <summary>
+        /// Runs the specified function in exclusive mode.
+        /// </summary>
+        /// <typeparam name="T">The result type.</typeparam>
+        /// <param name="console">The console.</param>
+        /// <param name="func">The func to run in exclusive mode.</param>
+        /// <returns>The result of the function.</returns>
+        public static T RunExclusive<T>(this IAnsiConsole console, Func<T> func)
+        {
+            return console.ExclusivityMode.Run(func);
+        }
+
+        /// <summary>
+        /// Runs the specified function in exclusive mode asynchronously.
+        /// </summary>
+        /// <typeparam name="T">The result type.</typeparam>
+        /// <param name="console">The console.</param>
+        /// <param name="func">The func to run in exclusive mode.</param>
+        /// <returns>The result of the function.</returns>
+        public static Task<T> RunExclusive<T>(this IAnsiConsole console, Func<Task<T>> func)
+        {
+            return console.ExclusivityMode.Run(func);
+        }
+    }
+}

src/Spectre.Console/IAnsiConsole.cs

@@ -23,6 +23,11 @@ namespace Spectre.Console
         /// </summary>
         IAnsiConsoleInput Input { get; }
 
+        /// <summary>
+        /// Gets the exclusivity mode.
+        /// </summary>
+        IExclusivityMode ExclusivityMode { get; }
+
         /// <summary>
         /// Gets the render pipeline.
         /// </summary>

src/Spectre.Console/IExclusivityMode.cs

@@ -0,0 +1,27 @@
+using System;
+using System.Threading.Tasks;
+
+namespace Spectre.Console
+{
+    /// <summary>
+    /// Represents an exclusivity mode.
+    /// </summary>
+    public interface IExclusivityMode
+    {
+        /// <summary>
+        /// Runs the specified function in exclusive mode.
+        /// </summary>
+        /// <typeparam name="T">The result type.</typeparam>
+        /// <param name="func">The func to run in exclusive mode.</param>
+        /// <returns>The result of the function.</returns>
+        T Run<T>(Func<T> func);
+
+        /// <summary>
+        /// Runs the specified function in exclusive mode asynchronously.
+        /// </summary>
+        /// <typeparam name="T">The result type.</typeparam>
+        /// <param name="func">The func to run in exclusive mode.</param>
+        /// <returns>The result of the function.</returns>
+        Task<T> Run<T>(Func<Task<T>> func);
+    }
+}

src/Spectre.Console/Internal/Backends/AnsiConsoleFacade.cs

@@ -13,9 +13,10 @@ namespace Spectre.Console
         public Profile Profile { get; }
         public IAnsiConsoleCursor Cursor => GetBackend().Cursor;
         public IAnsiConsoleInput Input { get; }
+        public IExclusivityMode ExclusivityMode { get; }
         public RenderPipeline Pipeline { get; }
 
-        public AnsiConsoleFacade(Profile profile)
+        public AnsiConsoleFacade(Profile profile, IExclusivityMode exclusivityMode)
         {
             _renderLock = new object();
             _ansiBackend = new AnsiConsoleBackend(profile);
@@ -23,6 +24,7 @@ namespace Spectre.Console
 
             Profile = profile ?? throw new ArgumentNullException(nameof(profile));
             Input = new DefaultInput(Profile);
+            ExclusivityMode = exclusivityMode ?? throw new ArgumentNullException(nameof(exclusivityMode));
             Pipeline = new RenderPipeline();
         }
 

src/Spectre.Console/Internal/Cell.cs

@@ -1,4 +1,3 @@
-using System.Linq;
 using Spectre.Console.Rendering;
 using Wcwidth;
 

src/Spectre.Console/Internal/DefaultExclusivityMode.cs

@@ -0,0 +1,57 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Spectre.Console.Internal
+{
+    internal sealed class DefaultExclusivityMode : IExclusivityMode
+    {
+        private static readonly SemaphoreSlim _semaphore;
+
+        static DefaultExclusivityMode()
+        {
+            _semaphore = new SemaphoreSlim(1, 1);
+        }
+
+        public T Run<T>(Func<T> func)
+        {
+            // Try aquiring the exclusivity semaphore
+            if (!_semaphore.Wait(0))
+            {
+                throw new InvalidOperationException(
+                    "Trying to run one or more interactive functions concurrently. " +
+                    "Operations with dynamic displays (e.g. a prompt and a progress display) " +
+                    "cannot be running at the same time.");
+            }
+
+            try
+            {
+                return func();
+            }
+            finally
+            {
+                _semaphore.Release(1);
+            }
+        }
+
+        public async Task<T> Run<T>(Func<Task<T>> func)
+        {
+            // Try aquiring the exclusivity semaphore
+            if (!await _semaphore.WaitAsync(0).ConfigureAwait(false))
+            {
+                // TODO: Need a better message here
+                throw new InvalidOperationException(
+                    "Could not aquire the interactive semaphore");
+            }
+
+            try
+            {
+                return await func();
+            }
+            finally
+            {
+                _semaphore.Release(1);
+            }
+        }
+    }
+}

src/Spectre.Console/Recorder.cs

@@ -23,6 +23,9 @@ namespace Spectre.Console
         /// <inheritdoc/>
         public IAnsiConsoleInput Input => _console.Input;
 
+        /// <inheritdoc/>
+        public IExclusivityMode ExclusivityMode => _console.ExclusivityMode;
+
         /// <inheritdoc/>
         public RenderPipeline Pipeline => _console.Pipeline;
 

src/Spectre.Console/Widgets/Progress/Progress.cs

@@ -118,6 +118,8 @@ namespace Spectre.Console
                 throw new ArgumentNullException(nameof(action));
             }
 
+            return await _console.RunExclusive(async () =>
+            {
                 var renderer = CreateRenderer();
                 renderer.Started();
 
@@ -150,6 +152,7 @@ namespace Spectre.Console
                 }
 
                 return result;
+            }).ConfigureAwait(false);
         }
 
         private ProgressRenderer CreateRenderer()

src/Spectre.Console/Widgets/Prompt/MultiSelectionPrompt.cs

@@ -72,6 +72,11 @@ namespace Spectre.Console
         /// <inheritdoc/>
         public List<T> Show(IAnsiConsole console)
         {
+            if (console is null)
+            {
+                throw new ArgumentNullException(nameof(console));
+            }
+
             if (!console.Profile.Capabilities.Interactive)
             {
                 throw new NotSupportedException(
@@ -86,6 +91,8 @@ namespace Spectre.Console
                     "terminal does not support ANSI escape sequences.");
             }
 
+            return console.RunExclusive(() =>
+            {
                 var converter = Converter ?? TypeConverterHelper.ConvertToString;
                 var list = new RenderableMultiSelectionList<T>(
                     console, Title, PageSize, Choices,
@@ -130,6 +137,7 @@ namespace Spectre.Console
                 return list.Selections
                     .Select(index => Choices[index])
                     .ToList();
+            });
         }
     }
 }

src/Spectre.Console/Widgets/Prompt/SelectionPrompt.cs

@@ -68,6 +68,8 @@ namespace Spectre.Console
                     "terminal does not support ANSI escape sequences.");
             }
 
+            return console.RunExclusive(() =>
+            {
                 var converter = Converter ?? TypeConverterHelper.ConvertToString;
                 var list = new RenderableSelectionList<T>(
                     console, Title, PageSize, Choices,
@@ -97,6 +99,7 @@ namespace Spectre.Console
                 console.Cursor.Show();
 
                 return Choices[list.Index];
+            });
         }
     }
 }

src/Spectre.Console/Widgets/Prompt/TextPrompt.cs

@@ -100,6 +100,8 @@ namespace Spectre.Console
                 throw new ArgumentNullException(nameof(console));
             }
 
+            return console.RunExclusive(() =>
+            {
                 var promptStyle = PromptStyle ?? Style.Plain;
                 var converter = Converter ?? TypeConverterHelper.ConvertToString;
                 var choices = Choices.Select(choice => converter(choice)).ToList();
@@ -160,6 +162,7 @@ namespace Spectre.Console
 
                     return result;
                 }
+            });
         }
 
         /// <summary>