.NET: Reduce re-rendering in harness console

dotnet/samples/02-agents/Harness/ConsoleReactiveComponents/ListSelection.cs

@@ -39,7 +39,7 @@ public override void RenderCore(ListSelectionProps props, ConsoleReactiveState s
         {
             foreach (string line in props.Title.Split('\n'))
             {
-                Console.Write(AnsiEscapes.MoveCursor(this.Y + row, this.X));
+                Console.Write(AnsiEscapes.MoveCursor(props.Y + row, props.X));
                 Console.Write(AnsiEscapes.EraseEntireLine);
                 Console.Write(line);
                 row++;
@@ -51,7 +51,7 @@ public override void RenderCore(ListSelectionProps props, ConsoleReactiveState s
 
         for (int i = 0; i < totalItems; i++)
         {
-            Console.Write(AnsiEscapes.MoveCursor(this.Y + row, this.X));
+            Console.Write(AnsiEscapes.MoveCursor(props.Y + row, props.X));
             Console.Write(AnsiEscapes.EraseEntireLine);
 
             bool isSelected = i == props.SelectedIndex;

dotnet/samples/02-agents/Harness/ConsoleReactiveComponents/TextInput.cs

@@ -58,11 +58,11 @@ public static int CalculateHeight(TextInputProps props, int availableWidth)
     public override void RenderCore(TextInputProps props, ConsoleReactiveState state)
     {
         int promptLength = props.Prompt.Length;
-        int textWidth = this.Width - promptLength;
+        int textWidth = props.Width - promptLength;
         string indent = new(' ', promptLength);
 
         // First line: prompt + start of text
-        Console.Write(AnsiEscapes.MoveCursor(this.Y, this.X));
+        Console.Write(AnsiEscapes.MoveCursor(props.Y, props.X));
         Console.Write(AnsiEscapes.EraseEntireLine);
         Console.Write(props.Prompt);
 
@@ -90,7 +90,7 @@ public override void RenderCore(TextInputProps props, ConsoleReactiveState state
         while (offset < props.Text.Length)
         {
             int chunk = Math.Min(textWidth, props.Text.Length - offset);
-            Console.Write(AnsiEscapes.MoveCursor(this.Y + row, this.X));
+            Console.Write(AnsiEscapes.MoveCursor(props.Y + row, props.X));
             Console.Write(AnsiEscapes.EraseEntireLine);
             Console.Write(indent);
             Console.Write(props.Text[offset..(offset + chunk)]);

dotnet/samples/02-agents/Harness/ConsoleReactiveComponents/TextPanel.cs

@@ -17,7 +17,7 @@ public record TextPanelProps : ConsoleReactiveProps
 /// <summary>
 /// A component that renders a list of pre-rendered string items vertically.
 /// Designed for rendering dynamic items in a non-scroll region that may be
-/// re-rendered on each update. If the component's <see cref="ConsoleReactiveComponent.Height"/>
+/// re-rendered on each update. If the component's <see cref="ConsoleReactiveProps.Height"/>
 /// exceeds the number of output lines, leftover lines are erased.
 /// </summary>
 public class TextPanel : ConsoleReactiveComponent<TextPanelProps, ConsoleReactiveState>
@@ -51,18 +51,18 @@ public override void RenderCore(TextPanelProps props, ConsoleReactiveState state
 
             for (int j = 0; j < lineCount; j++)
             {
-                Console.Write(AnsiEscapes.MoveAndEraseLine(this.Y + currentRow));
+                Console.Write(AnsiEscapes.MoveAndEraseLine(props.Y + currentRow));
                 Console.Write(lines[j]);
                 currentRow++;
             }
         }
 
         // If the component height exceeds the output, erase leftover lines
-        if (this.Height > currentRow)
+        if (props.Height > currentRow)
         {
-            for (int i = currentRow; i < this.Height; i++)
+            for (int i = currentRow; i < props.Height; i++)
             {
-                Console.Write(AnsiEscapes.MoveAndEraseLine(this.Y + i));
+                Console.Write(AnsiEscapes.MoveAndEraseLine(props.Y + i));
             }
         }
     }

dotnet/samples/02-agents/Harness/ConsoleReactiveComponents/TextScrollPanel.cs

@@ -52,7 +52,7 @@ public override void RenderCore(TextScrollPanelProps props, TextScrollPanelState
         }
 
         // Move cursor to the bottom of the scroll area
-        Console.Write(AnsiEscapes.MoveCursor(this.Y + this.Height - 1, this.X));
+        Console.Write(AnsiEscapes.MoveCursor(props.Y + props.Height - 1, props.X));
 
         // Output only new items since last rendered
         for (int i = state.RenderedCount; i < props.Items.Count; i++)

dotnet/samples/02-agents/Harness/ConsoleReactiveComponents/TopBottomRule.cs

@@ -9,9 +9,6 @@ namespace Harness.ConsoleReactiveComponents;
 /// </summary>
 public record TopBottomRuleProps : ConsoleReactiveProps
 {
-    /// <summary>Gets the width of the horizontal rules in characters.</summary>
-    public int Width { get; init; }
-
     /// <summary>Gets the foreground color of the horizontal rules. If <c>null</c>, the default terminal color is used.</summary>
     public ConsoleColor? Color { get; init; }
 }
@@ -32,7 +29,7 @@ public static int CalculateHeight(TopBottomRuleProps props)
         int childrenHeight = 0;
         foreach (var child in props.Children)
         {
-            childrenHeight += child.Height;
+            childrenHeight += child.BaseProps?.Height ?? 0;
         }
 
         // Top rule + children + bottom rule
@@ -51,11 +48,11 @@ public override void RenderCore(TopBottomRuleProps props, ConsoleReactiveState s
         }
 
         // Top rule
-        Console.Write(AnsiEscapes.MoveCursor(this.Y, this.X));
+        Console.Write(AnsiEscapes.MoveCursor(props.Y, props.X));
         Console.Write(rule);
 
         // Render children stacked below the top rule
-        int currentY = this.Y + 1;
+        int currentY = props.Y + 1;
 
         if (props.Color.HasValue)
         {
@@ -64,10 +61,9 @@ public override void RenderCore(TopBottomRuleProps props, ConsoleReactiveState s
 
         foreach (var child in props.Children)
         {
-            child.X = this.X;
-            child.Y = currentY;
+            child.BaseProps = child.BaseProps! with { X = props.X, Y = currentY };
             child.Render();
-            currentY += child.Height;
+            currentY += child.BaseProps.Height;
         }
 
         if (props.Color.HasValue)
@@ -76,7 +72,7 @@ public override void RenderCore(TopBottomRuleProps props, ConsoleReactiveState s
         }
 
         // Bottom rule
-        Console.Write(AnsiEscapes.MoveCursor(currentY, this.X));
+        Console.Write(AnsiEscapes.MoveCursor(currentY, props.X));
         Console.Write(rule);
 
         if (props.Color.HasValue)

dotnet/samples/02-agents/Harness/ConsoleReactiveFramework/ConsoleReactiveComponent.cs

@@ -3,8 +3,8 @@
 namespace Harness.ConsoleReactiveFramework;
 
 /// <summary>
-/// Abstract base class for all console UI components. Provides layout properties
-/// (position and size) and a <see cref="Render"/> method for drawing to the console.
+/// Abstract base class for all console UI components. Provides access to layout
+/// through <see cref="BaseProps"/> and a <see cref="Render"/> method for drawing to the console.
 /// Derive from <see cref="ConsoleReactiveComponent{TProps, TState}"/> instead of this class directly.
 /// </summary>
 public abstract class ConsoleReactiveComponent
@@ -13,20 +13,21 @@ internal ConsoleReactiveComponent()
     {
     }
 
-    /// <summary>Gets or sets the 1-based column position of the component.</summary>
-    public int X { get; set; }
-
-    /// <summary>Gets or sets the 1-based row position of the component.</summary>
-    public int Y { get; set; }
-
-    /// <summary>Gets or sets the width of the component in columns.</summary>
-    public int Width { get; set; }
-
-    /// <summary>Gets or sets the height of the component in rows.</summary>
-    public int Height { get; set; }
+    /// <summary>
+    /// Gets or sets the component's props as the base <see cref="ConsoleReactiveProps"/> type.
+    /// Used by parent components to set layout (X, Y, Width, Height) on children without
+    /// knowing the concrete props type.
+    /// </summary>
+    public abstract ConsoleReactiveProps? BaseProps { get; set; }
 
     /// <summary>Renders the component to the console at its current position.</summary>
     public abstract void Render();
+
+    /// <summary>
+    /// Invalidates the component's cached render state, causing the next <see cref="Render"/> call
+    /// to proceed even if props and state have not changed. Use after a screen erase to force repaint.
+    /// </summary>
+    public abstract void Invalidate();
 }
 
 /// <summary>
@@ -46,6 +47,13 @@ public abstract class ConsoleReactiveComponent<TProps, TState> : ConsoleReactive
     /// <summary>Gets or sets the component's props (external configuration).</summary>
     public TProps? Props { get; set; }
 
+    /// <inheritdoc/>
+    public override ConsoleReactiveProps? BaseProps
+    {
+        get => this.Props;
+        set => this.Props = (TProps?)value;
+    }
+
     /// <summary>Gets or sets the component's internal state.</summary>
     protected TState? State { get; set; }
 
@@ -73,8 +81,8 @@ public override void Render()
                 return;
             }
 
-            if (ReferenceEquals(this.Props, this._lastRenderedProps)
-                && ReferenceEquals(this.State, this._lastRenderedState))
+            if (EqualityComparer<TProps>.Default.Equals(this.Props, this._lastRenderedProps)
+                && EqualityComparer<TState>.Default.Equals(this.State, this._lastRenderedState))
             {
                 return;
             }
@@ -86,6 +94,16 @@ public override void Render()
         }
     }
 
+    /// <inheritdoc/>
+    public override void Invalidate()
+    {
+        lock (this._renderLock)
+        {
+            this._lastRenderedProps = default;
+            this._lastRenderedState = default;
+        }
+    }
+
     /// <summary>
     /// Called by <see cref="Render"/> to perform the actual rendering. Override this in derived classes.
     /// </summary>
@@ -95,11 +113,23 @@ public override void Render()
 }
 
 /// <summary>
-/// Base record for component props. Provides an optional <see cref="Children"/> collection
-/// for composing child components.
+/// Base record for component props. Provides layout properties (position and size)
+/// and an optional <see cref="Children"/> collection for composing child components.
 /// </summary>
 public record ConsoleReactiveProps
 {
+    /// <summary>Gets the 1-based column position of the component.</summary>
+    public int X { get; init; }
+
+    /// <summary>Gets the 1-based row position of the component.</summary>
+    public int Y { get; init; }
+
+    /// <summary>Gets the width of the component in columns.</summary>
+    public int Width { get; init; }
+
+    /// <summary>Gets the height of the component in rows.</summary>
+    public int Height { get; init; }
+
     /// <summary>Gets the child components to render within this component.</summary>
     public IReadOnlyList<ConsoleReactiveComponent> Children { get; init; } = [];
 }

dotnet/samples/02-agents/Harness/Harness_Shared_Console/Components/AgentModeAndHelp.cs

@@ -43,7 +43,7 @@ public override void RenderCore(AgentModeAndHelpProps props, ConsoleReactiveStat
         }
 
         System.Console.Write(AnsiEscapes.SaveCursor);
-        System.Console.Write(AnsiEscapes.MoveAndEraseLine(this.Y));
+        System.Console.Write(AnsiEscapes.MoveAndEraseLine(props.Y));
 
         bool hasMode = props.Mode is not null;
 

dotnet/samples/02-agents/Harness/Harness_Shared_Console/Components/AgentStatus.cs

@@ -86,7 +86,7 @@ public override void RenderCore(AgentStatusProps props, AgentStatusState state)
         }
 
         System.Console.Write(AnsiEscapes.SaveCursor);
-        System.Console.Write(AnsiEscapes.MoveCursor(this.Y, this.X));
+        System.Console.Write(AnsiEscapes.MoveCursor(props.Y, props.X));
         if (props != this._previousProps)
         {
             System.Console.Write(AnsiEscapes.EraseToEndOfLine);