StackPanel child visibility change handler

src/Library/TerminalUI/Controls/Grid.cs

@@ -9,10 +9,10 @@ namespace TerminalUI.Controls;
 
 public class Grid<T> : ChildContainerView<T>, IVisibilityChangeHandler
 {
+    private readonly List<IView> _forceRerenderChildren = new();
+    private readonly object _forceRerenderChildrenLock = new();
     private List<RowDefinition> _rowDefinitions = new() {RowDefinition.Star(1)};
     private List<ColumnDefinition> _columnDefinitions = new() {ColumnDefinition.Star(1)};
-    private List<IView> _forceRerenderChildren = new();
-    private readonly object _forceRerenderChildrenLock = new();
     private ILogger<Grid<T>>? Logger => ApplicationContext?.LoggerFactory?.CreateLogger<Grid<T>>();
 
     private delegate void WithSizes(RenderContext renderContext, ReadOnlySpan<int> widths, ReadOnlySpan<int> heights);
@@ -156,7 +156,7 @@ public class Grid<T> : ChildContainerView<T>, IVisibilityChangeHandler
                 IReadOnlyList<IView> forceRerenderChildren;
                 lock (_forceRerenderChildrenLock)
                 {
-                    forceRerenderChildren = _forceRerenderChildren;
+                    forceRerenderChildren = _forceRerenderChildren.ToList();
                     _forceRerenderChildren.Clear();
                 }
 

src/Library/TerminalUI/Controls/StackPanel.cs

@@ -1,11 +1,13 @@
-using System.Collections.ObjectModel;
-using PropertyChanged.SourceGenerator;
+using PropertyChanged.SourceGenerator;
 using TerminalUI.Models;
+using TerminalUI.Traits;
 
 namespace TerminalUI.Controls;
 
-public partial class StackPanel<T> : ChildContainerView<T>
+public partial class StackPanel<T> : ChildContainerView<T>, IVisibilityChangeHandler
 {
+    private readonly List<IView> _forceRerenderChildren = new();
+    private readonly object _forceRerenderChildrenLock = new();
     private readonly Dictionary<IView, Size> _requestedSizes = new();
     [Notify] private Orientation _orientation = Orientation.Vertical;
 
@@ -41,12 +43,29 @@ public partial class StackPanel<T> : ChildContainerView<T>
     {
         var delta = 0;
         var neededRerender = false;
+        IReadOnlyList<IView> forceRerenderChildren;
+        lock (_forceRerenderChildrenLock)
+        {
+            forceRerenderChildren = _forceRerenderChildren.ToList();
+            _forceRerenderChildren.Clear();
+        }
+
         foreach (var child in Children)
         {
             if (!child.IsVisible) continue;
 
             if (!_requestedSizes.TryGetValue(child, out var childSize)) throw new Exception("Child size not found");
 
+            if (forceRerenderChildren.Contains(child))
+            {
+                renderContext = new RenderContext(
+                    renderContext.ConsoleDriver,
+                    true,
+                    renderContext.Foreground,
+                    renderContext.Background
+                );
+            }
+
             var childPosition = Orientation == Orientation.Vertical
                 ? position with {Y = position.Y + delta}
                 : position with {X = position.X + delta};
@@ -74,4 +93,20 @@ public partial class StackPanel<T> : ChildContainerView<T>
 
         return neededRerender;
     }
+
+    public void ChildVisibilityChanged(IView child)
+    {
+        var viewToForceRerender = child;
+        while (viewToForceRerender.VisualParent != null && viewToForceRerender.VisualParent != this)
+        {
+            viewToForceRerender = viewToForceRerender.VisualParent;
+        }
+
+        if (viewToForceRerender.VisualParent != this) return;
+
+        lock (_forceRerenderChildrenLock)
+        {
+            _forceRerenderChildren.Add(viewToForceRerender);
+        }
+    }
 }