Console MessageBox, admin mode

src/Library/TerminalUI/ConsoleDrivers/DotnetDriver.cs

@@ -11,6 +11,7 @@ public class DotnetDriver : IConsoleDriver
     public int ThreadId { get; set; }
 
     public void EnterRestrictedMode() => CheckThreadId = true;
+    public void ExitRestrictedMode() => CheckThreadId = false;
 
     public virtual bool Init()
     {

src/Library/TerminalUI/ConsoleDrivers/IConsoleDriver.cs

@@ -24,4 +24,5 @@ public interface IConsoleDriver
     Size GetWindowSize();
     void Clear();
     void EnterRestrictedMode();
+    void ExitRestrictedMode();
 }

src/Library/TerminalUI/Controls/Button.cs

@@ -0,0 +1,94 @@
+using GeneralInputKey;
+using PropertyChanged.SourceGenerator;
+using TerminalUI.Color;
+using TerminalUI.ConsoleDrivers;
+using TerminalUI.Models;
+using TerminalUI.Traits;
+
+namespace TerminalUI.Controls;
+
+public partial class Button<T> : ContentView<Button<T>, T>, IFocusable 
+{
+    private record RenderState(IColor? Foreground, IColor? Background);
+
+    private Position? _cursorRenderPosition;
+    private RenderState? _lastRenderState;
+
+    [Notify] private Position? _cursorPosition;
+    private List<Action<Button<T>>> _clickHandlers = new();
+
+    public Button()
+    {
+        RerenderProperties.Add(nameof(CursorPosition));
+    }
+
+    public void Focus()
+        => ApplicationContext?.FocusManager.SetFocus(this);
+
+    public void UnFocus()
+        => ApplicationContext?.FocusManager.UnFocus(this);
+
+    public void SetCursorPosition(IConsoleDriver consoleDriver)
+    {
+        if (_cursorRenderPosition is null) return;
+        consoleDriver.SetCursorPosition(_cursorRenderPosition.Value);
+    }
+
+    protected override Size CalculateSize()
+    {
+        if (Content is null || !Content.IsVisible) return new Size(0, 0);
+
+        return Content.GetRequestedSize();
+    }
+
+    protected override bool DefaultRenderer(in RenderContext renderContext, Position position, Size size)
+    {
+        if (ContentRendererMethod is null)
+        {
+            throw new NullReferenceException(
+                nameof(ContentRendererMethod)
+                + " is null, cannot render content of "
+                + Content?.GetType().Name
+                + " with DataContext of "
+                + DataContext?.GetType().Name);
+        }
+
+        var backgroundColor = Background ?? renderContext.Background;
+        var foregroundColor = Foreground ?? renderContext.Foreground;
+
+        var renderState = new RenderState(foregroundColor, backgroundColor);
+
+        var forceRerender = !renderContext.ForceRerender && !NeedsRerender(renderState);
+        _lastRenderState = renderState;
+
+        var childRenderContext = renderContext with
+        {
+            Background = backgroundColor,
+            Foreground = foregroundColor,
+            ForceRerender = forceRerender
+        };
+
+        _cursorRenderPosition = position;
+
+        return ContentRendererMethod(childRenderContext, position, size);
+    }
+
+    private bool NeedsRerender(RenderState renderState) => renderState != _lastRenderState;
+
+    public override void HandleKeyInput(GeneralKeyEventArgs keyEventArgs)
+    {
+        if (keyEventArgs.Key != Keys.Enter) return;
+
+        keyEventArgs.Handled = true;
+        foreach (var clickHandler in _clickHandlers)
+        {
+            clickHandler(this);
+        }
+    }
+
+    public Button<T> WithClickHandler(Action<Button<T>> handler)
+    {
+        _clickHandlers.Add(handler);
+        return this;
+    }
+}

src/Library/TerminalUI/Controls/ItemsControl.cs

@@ -125,8 +125,7 @@ public sealed partial class ItemsControl<TDataContext, TItem>
         {
             if (!child.IsVisible) continue;
 
-            if (!_requestedSizes.TryGetValue(child, out var childSize)) throw new Exception("Child size not found");
-
+            if (!_requestedSizes.TryGetValue(child, out var childSize)) continue;
 
             var childPosition = Orientation == Orientation.Vertical
                 ? position with {Y = position.Y + delta}

src/Library/TerminalUI/EventLoop.cs

@@ -8,6 +8,7 @@ public class EventLoop : IEventLoop
     private readonly ILogger<EventLoop> _logger;
     private readonly List<Action> _initializers = new();
     private readonly List<Action> _permanentQueue = new();
+    private readonly List<Action> _finalizers = new();
 
     public int ThreadId { get; set; } = -1;
     
@@ -21,6 +22,7 @@ public class EventLoop : IEventLoop
 
     public void AddToPermanentQueue(Action action) => _permanentQueue.Add(action);
     public void AddInitializer(Action action) => _initializers.Add(action);
+    public void AddFinalizer(Action action) => _finalizers.Add(action);
 
     public void Run()
     {
@@ -35,6 +37,10 @@ public class EventLoop : IEventLoop
             ProcessQueues();
             Thread.Sleep(10);
         }
+        foreach (var finalizer in _finalizers)
+        {
+            finalizer();
+        }
         ThreadId = -1;
     }
 

src/Library/TerminalUI/IEventLoop.cs

@@ -6,4 +6,5 @@ public interface IEventLoop
     void AddToPermanentQueue(Action action);
     void AddInitializer(Action action);
     int ThreadId { get; set; }
+    void AddFinalizer(Action action);
 }

src/Library/TerminalUI/RenderEngine.cs

@@ -33,6 +33,10 @@ public class RenderEngine : IRenderEngine
             _applicationContext.ConsoleDriver.ThreadId = _eventLoop.ThreadId;
             _applicationContext.ConsoleDriver.EnterRestrictedMode();
         });
+        _eventLoop.AddFinalizer(() =>
+        {
+            _applicationContext.ConsoleDriver.ExitRestrictedMode();
+        });
     }
 
     public void RequestRerender(IView view) => RequestRerender();