Implement new TextFormatter architecture with separated formatter and renderer

Co-authored-by: tig <585482+tig@users.noreply.github.com>

Tests/UnitTestsParallelizable/Text/TextFormatterNewArchitectureTests.cs

@@ -0,0 +1,151 @@
+using System.Drawing;
+using Terminal.Gui.Text;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace Terminal.Gui.TextTests;
+
+/// <summary>
+/// Tests for the new TextFormatter architecture that separates formatting from rendering.
+/// </summary>
+public class TextFormatterNewArchitectureTests
+{
+    private readonly ITestOutputHelper _output;
+
+    public TextFormatterNewArchitectureTests(ITestOutputHelper output)
+    {
+        _output = output;
+    }
+
+    [Fact]
+    public void TextFormatter_NewArchitecture_BasicFormatting_Works()
+    {
+        Application.Init(new FakeDriver());
+
+        var tf = new TextFormatter
+        {
+            Text = "Hello World"
+        };
+
+        // Test the new architecture method
+        Size size = tf.GetFormattedSizeWithNewArchitecture();
+        
+        Assert.True(size.Width > 0);
+        Assert.True(size.Height > 0);
+        
+        Application.Shutdown();
+    }
+
+    [Fact]
+    public void TextFormatter_NewArchitecture_WithAlignment_Works()
+    {
+        Application.Init(new FakeDriver());
+
+        var tf = new TextFormatter
+        {
+            Text = "Hello World",
+            Alignment = Alignment.Center,
+            VerticalAlignment = Alignment.Center
+        };
+
+        // Test that properties are synchronized
+        Size size = tf.GetFormattedSizeWithNewArchitecture();
+        
+        Assert.True(size.Width > 0);
+        Assert.True(size.Height > 0);
+        
+        Application.Shutdown();
+    }
+
+    [Fact]
+    public void TextFormatter_NewArchitecture_Performance_IsBetter()
+    {
+        Application.Init(new FakeDriver());
+
+        var tf = new TextFormatter
+        {
+            Text = "This is a long text that will be formatted multiple times to test performance improvements"
+        };
+
+        // Warm up
+        tf.GetFormattedSizeWithNewArchitecture();
+
+        // Test multiple calls - should use caching
+        var sw = System.Diagnostics.Stopwatch.StartNew();
+        for (int i = 0; i < 100; i++)
+        {
+            tf.GetFormattedSizeWithNewArchitecture();
+        }
+        sw.Stop();
+
+        _output.WriteLine($"New architecture: 100 calls took {sw.ElapsedMilliseconds}ms");
+        
+        // The new architecture should be fast due to caching
+        Assert.True(sw.ElapsedMilliseconds < 100, "New architecture should be fast due to caching");
+        
+        Application.Shutdown();
+    }
+
+    [Fact]
+    public void TextFormatter_NewArchitecture_DrawRegion_Works()
+    {
+        Application.Init(new FakeDriver());
+
+        var tf = new TextFormatter
+        {
+            Text = "Hello\nWorld"
+        };
+
+        Region region = tf.GetDrawRegionWithNewArchitecture(new Rectangle(0, 0, 10, 10));
+        
+        Assert.NotNull(region);
+        
+        Application.Shutdown();
+    }
+
+    [Fact]
+    public void StandardTextFormatter_DirectlyUsed_Works()
+    {
+        var formatter = new StandardTextFormatter
+        {
+            Text = "Test Text",
+            Alignment = Alignment.Center
+        };
+
+        FormattedText result = formatter.Format();
+        
+        Assert.NotNull(result);
+        Assert.NotEmpty(result.Lines);
+        Assert.True(result.RequiredSize.Width > 0);
+        Assert.True(result.RequiredSize.Height > 0);
+    }
+
+    [Fact]
+    public void StandardTextRenderer_DirectlyUsed_Works()
+    {
+        Application.Init(new FakeDriver());
+        
+        var formatter = new StandardTextFormatter
+        {
+            Text = "Test Text"
+        };
+        
+        var renderer = new StandardTextRenderer();
+        FormattedText formattedText = formatter.Format();
+        
+        // Should not throw
+        renderer.Draw(
+            formattedText, 
+            new Rectangle(0, 0, 10, 1), 
+            Attribute.Default, 
+            Attribute.Default);
+            
+        Region region = renderer.GetDrawRegion(
+            formattedText, 
+            new Rectangle(0, 0, 10, 1));
+            
+        Assert.NotNull(region);
+        
+        Application.Shutdown();
+    }
+}