Add PreBufferPaint event and minor improvements

- Add PreBufferPaint event to WindowRenderer for rendering content
  behind controls (games, animations, custom backgrounds)
- Rename PostBufferPaintDelegate to BufferPaintDelegate for clarity
- Minor updates to WindowStateService, FileDialogs, and ClassicTheme

Author: nickprotop

SharpConsoleUI/Core/WindowStateService.cs

@@ -1017,6 +1017,13 @@ public bool CloseWindow(Window? window, bool activateParent = true, bool force =
 			{
 				w.Invalidate(true);
 			}
+
+			// Force flush when no windows remain - the main loop won't render
+			// because AnyWindowDirty() returns false with an empty window collection
+			if (context.Windows.Count == 0)
+			{
+				_consoleDriver.Flush();
+			}
 		}
 
 		return true;

SharpConsoleUI/Dialogs/FileDialogs.cs

@@ -71,8 +71,6 @@ public static class FileDialogs
 		if (!Directory.Exists(currentPath))
 			currentPath = Environment.CurrentDirectory;
 
-		var theme = windowSystem.Theme;
-
 		// Create modal window
 		var builder = new WindowBuilder(windowSystem)
 			.WithTitle(title)
@@ -82,8 +80,7 @@ public static class FileDialogs
 			.Resizable(true)
 			.Minimizable(false)
 			.Maximizable(true)
-			.Movable(true)
-			.WithColors(theme.ModalBackgroundColor, theme.WindowForegroundColor);
+			.Movable(true);
 
 		if (parentWindow != null)
 			builder.WithParent(parentWindow);
@@ -101,17 +98,13 @@ public static class FileDialogs
 
 		// Separator
 		modal.AddControl(Ctl.RuleBuilder()
-			.WithColor(Color.Grey23)
-			.Build());
+						.Build());
 
 		// Create folder list
 		var folderList = Ctl.List()
 			.WithAlignment(HorizontalAlignment.Stretch)
 			.WithVerticalAlignment(VerticalAlignment.Fill)
-			.WithColors(theme.ModalBackgroundColor, theme.WindowForegroundColor)
-			.WithFocusedColors(theme.ModalBackgroundColor, theme.WindowForegroundColor)
-			.WithHighlightColors(Color.Grey35, Color.White)
-			.SimpleMode()
+									.SimpleMode()
 			.WithDoubleClickActivation(true)
 			.WithName("FolderList")
 			.Build();
@@ -123,9 +116,6 @@ public static class FileDialogs
 			fileList = Ctl.List()
 				.WithAlignment(HorizontalAlignment.Stretch)
 				.WithVerticalAlignment(VerticalAlignment.Fill)
-				.WithColors(theme.ModalBackgroundColor, theme.WindowForegroundColor)
-				.WithFocusedColors(theme.ModalBackgroundColor, theme.WindowForegroundColor)
-				.WithHighlightColors(Color.Grey35, Color.White)
 				.SimpleMode()
 				.WithDoubleClickActivation(true)
 				.WithName("FileList")
@@ -256,8 +246,7 @@ void PopulateFileList(string path)
 
 		// Bottom separator
 		modal.AddControl(Ctl.RuleBuilder()
-			.WithColor(Color.Grey23)
-			.StickyBottom()
+						.StickyBottom()
 			.Build());
 
 		// Footer with instructions
@@ -367,8 +356,6 @@ void PopulateFileList(string path)
 		if (!Directory.Exists(currentPath))
 			currentPath = Environment.CurrentDirectory;
 
-		var theme = windowSystem.Theme;
-
 		// Create modal window
 		var builder = new WindowBuilder(windowSystem)
 			.WithTitle(title)
@@ -378,8 +365,7 @@ void PopulateFileList(string path)
 			.Resizable(true)
 			.Minimizable(false)
 			.Maximizable(true)
-			.Movable(true)
-			.WithColors(theme.ModalBackgroundColor, theme.WindowForegroundColor);
+			.Movable(true);
 
 		if (parentWindow != null)
 			builder.WithParent(parentWindow);
@@ -397,17 +383,13 @@ void PopulateFileList(string path)
 
 		// Separator
 		modal.AddControl(Ctl.RuleBuilder()
-			.WithColor(Color.Grey23)
-			.Build());
+						.Build());
 
 		// Folder list (left panel)
 		var folderList = Ctl.List()
 			.WithAlignment(HorizontalAlignment.Stretch)
 			.WithVerticalAlignment(VerticalAlignment.Fill)
-			.WithColors(theme.ModalBackgroundColor, theme.WindowForegroundColor)
-			.WithFocusedColors(theme.ModalBackgroundColor, theme.WindowForegroundColor)
-			.WithHighlightColors(Color.Grey35, Color.White)
-			.SimpleMode()
+									.SimpleMode()
 			.WithDoubleClickActivation(true)
 			.WithName("FolderList")
 			.Build();
@@ -416,10 +398,7 @@ void PopulateFileList(string path)
 		var fileList = Ctl.List()
 			.WithAlignment(HorizontalAlignment.Stretch)
 			.WithVerticalAlignment(VerticalAlignment.Fill)
-			.WithColors(theme.ModalBackgroundColor, theme.WindowForegroundColor)
-			.WithFocusedColors(theme.ModalBackgroundColor, theme.WindowForegroundColor)
-			.WithHighlightColors(Color.Grey35, Color.White)
-			.SimpleMode()
+									.SimpleMode()
 			.WithDoubleClickActivation(true)
 			.WithName("FileList")
 			.Build();
@@ -538,8 +517,7 @@ void PopulateFileList(string path)
 
 		// Bottom separator
 		modal.AddControl(Ctl.RuleBuilder()
-			.WithColor(Color.Grey23)
-			.StickyBottom()
+						.StickyBottom()
 			.Build());
 
 		// Filename label and input
@@ -553,8 +531,7 @@ void PopulateFileList(string path)
 
 		// Footer separator
 		modal.AddControl(Ctl.RuleBuilder()
-			.WithColor(Color.Grey23)
-			.StickyBottom()
+						.StickyBottom()
 			.Build());
 
 		// Footer with instructions

SharpConsoleUI/Themes/ClassicTheme.cs

@@ -113,7 +113,7 @@ public ClassicTheme()
 		/// <summary>
 		/// Gets or sets the background color for the desktop area behind all windows.
 		/// </summary>
-		public Color DesktopBackgroundColor { get; set; } = Color.Black;
+		public Color DesktopBackgroundColor { get; set; } = Color.Grey15;
 
 		/// <summary>
 		/// Gets or sets the character used to fill the desktop background area.
@@ -123,7 +123,7 @@ public ClassicTheme()
 		/// <summary>
 		/// Gets or sets the foreground color for the desktop background character pattern.
 		/// </summary>
-		public Color DesktopForegroundColor { get; set; } = Color.White;
+		public Color DesktopForegroundColor { get; set; } = Color.Grey23;
 
 		/// <summary>
 		/// Gets or sets the foreground color for the border of inactive (unfocused) windows.

SharpConsoleUI/Windows/WindowRenderer.cs

@@ -52,30 +52,45 @@ public WindowRenderer(
 		#region Public Events
 
 		/// <summary>
-		/// Delegate for buffer post-processing after painting but before ANSI conversion.
+		/// Delegate for buffer painting events.
 		/// </summary>
-		/// <param name="buffer">The character buffer that was just painted.</param>
-		/// <param name="dirtyRegion">The region that was painted (or full bounds if entire buffer).</param>
+		/// <param name="buffer">The character buffer to paint to.</param>
+		/// <param name="dirtyRegion">The region being painted (or full bounds if entire buffer).</param>
 		/// <param name="clipRect">The clipping rectangle used during paint.</param>
-		public delegate void PostBufferPaintDelegate(
+		public delegate void BufferPaintDelegate(
 			CharacterBuffer buffer,
 			LayoutRect dirtyRegion,
 			LayoutRect clipRect);
 
 		/// <summary>
-		/// Raised after painting controls to the buffer but before converting to ANSI strings.
+		/// Raised BEFORE painting controls to the buffer.
+		/// </summary>
+		/// <remarks>
+		/// This event allows painting backgrounds, game graphics, or other content
+		/// that should appear BEHIND the controls. Controls will paint on top.
+		///
+		/// Example use cases:
+		/// - Game rendering (fractals, animations, sprites)
+		/// - Custom backgrounds
+		/// - Gradients or patterns behind UI
+		/// </remarks>
+		public event BufferPaintDelegate? PreBufferPaint;
+
+		/// <summary>
+		/// Raised AFTER painting controls to the buffer but before converting to ANSI strings.
 		/// </summary>
 		/// <remarks>
 		/// This event allows custom effects, transitions, filters, or compositor-style
 		/// manipulations on the rendered buffer. The buffer can be safely modified here.
+		/// Content painted here will appear ON TOP of controls.
 		///
 		/// Example use cases:
 		/// - Fade in/out transitions
 		/// - Blur effects for modal backgrounds
 		/// - Glow effects around focused controls
 		/// - Custom overlays and effects
 		/// </remarks>
-		public event PostBufferPaintDelegate? PostBufferPaint;
+		public event BufferPaintDelegate? PostBufferPaint;
 
 		#endregion
 
@@ -332,6 +347,18 @@ public void PaintDOM(LayoutRect clipRect, Color backgroundColor)
 			// Clear buffer (could optimize to only clear clipRect region, but full clear is simpler)
 			_buffer.Clear(backgroundColor);
 
+			PaintDOMWithoutClear(clipRect);
+		}
+
+		/// <summary>
+		/// Paints the DOM tree to the character buffer WITHOUT clearing first.
+		/// Used internally when PreBufferPaint has already painted content to preserve.
+		/// </summary>
+		/// <param name="clipRect">The clipping rectangle in window-space coordinates.</param>
+		private void PaintDOMWithoutClear(LayoutRect clipRect)
+		{
+			if (_rootNode == null || _buffer == null) return;
+
 			// Paint the tree with the provided clip rect
 			_rootNode.Paint(_buffer, clipRect);
 
@@ -529,8 +556,18 @@ public List<string> RebuildContentCacheDOM(
 				clipRect = new LayoutRect(0, 0, availableWidth, availableHeight);
 			}
 
-			// Paint to buffer with clip rect
-			PaintDOM(clipRect, backgroundColor);
+			// Clear buffer first (before any painting)
+			_buffer.Clear(backgroundColor);
+
+			// Fire pre-paint event for background rendering (games, custom backgrounds)
+			if (PreBufferPaint != null)
+			{
+				var dirtyRegion = new LayoutRect(0, 0, _buffer.Width, _buffer.Height);
+				PreBufferPaint.Invoke(_buffer, dirtyRegion, clipRect);
+			}
+
+			// Paint controls to buffer with clip rect (on top of pre-paint content)
+			PaintDOMWithoutClear(clipRect);
 
 			// Fire post-paint event for custom effects (e.g., transitions, filters)
 			if (PostBufferPaint != null && _buffer != null)