Measure/Arrange TextPresenter with WidthIncludingTrailingWhitespace (#21067)

src/Avalonia.Controls/Presenters/TextPresenter.cs

@@ -647,7 +647,7 @@ namespace Avalonia.Controls.Presenters
             InvalidateArrange();
 
             // The textWidth used here is matching that TextBlock uses to measure the text.
-            var textWidth = TextLayout.OverhangLeading + TextLayout.WidthIncludingTrailingWhitespace + TextLayout.OverhangTrailing;
+            var textWidth = TextLayout.WidthIncludingTrailingWhitespace;
             return new Size(textWidth, TextLayout.Height);
         }
 
@@ -655,7 +655,7 @@ namespace Avalonia.Controls.Presenters
         {
             var finalWidth = finalSize.Width;
 
-            var textWidth = TextLayout.OverhangLeading + TextLayout.WidthIncludingTrailingWhitespace + TextLayout.OverhangTrailing;
+            var textWidth = TextLayout.WidthIncludingTrailingWhitespace;
             textWidth = Math.Ceiling(textWidth);
 
             if (finalSize.Width < textWidth)

tests/Avalonia.Controls.UnitTests/Presenters/TextPresenter_Tests.cs

@@ -75,5 +75,30 @@ namespace Avalonia.Controls.UnitTests.Presenters
                 Assert.Equal(fontStretch, presenter.TextLayout.TextLines[0].TextRuns[0].Properties!.Typeface.Stretch);
             }
         }
+
+        [Fact]
+        public void Measure_And_Arrange_Should_Use_WidthIncludingTrailingWhitespace_For_Bounds()
+        {
+            using (UnitTestApplication.Start(TestServices.MockPlatformRenderInterface))
+            {
+                var presenter = new TextPresenter
+                {
+                    Text = "fy",
+                    FontStyle = FontStyle.Italic,
+                    FontSize = 48,
+                    UseLayoutRounding = false
+                };
+
+                presenter.Measure(Size.Infinity);
+
+                var expectedSize = new Size(presenter.TextLayout.WidthIncludingTrailingWhitespace, presenter.TextLayout.Height);
+
+                Assert.Equal(expectedSize, presenter.DesiredSize);
+
+                presenter.Arrange(new Rect(default, presenter.DesiredSize));
+
+                Assert.Equal(new Rect(default, expectedSize), presenter.Bounds);
+            }
+        }
     }
 }

tests/Avalonia.Controls.UnitTests/TextBlockTests.cs

@@ -561,6 +561,33 @@ namespace Avalonia.Controls.UnitTests
             Assert.Equal(new Rect(0, 0, 32.45454545454545, 19.022727272727273), target.Bounds);
         }
 
+        [Fact]
+        public void Measure_And_Arrange_Should_Use_WidthIncludingTrailingWhitespace_For_Bounds()
+        {
+            using var app = UnitTestApplication.Start(TestServices.MockPlatformRenderInterface);
+
+            var target = new TextBlock
+            {
+                Text = "fy",
+                FontStyle = FontStyle.Italic,
+                FontSize = 48,
+                UseLayoutRounding = false,
+                Padding = new Thickness(3, 2, 5, 4)
+            };
+
+            target.Measure(Size.Infinity);
+
+            var expectedSize =
+                new Size(target.TextLayout.WidthIncludingTrailingWhitespace, target.TextLayout.Height)
+                    .Inflate(target.Padding);
+
+            Assert.Equal(expectedSize, target.DesiredSize);
+
+            target.Arrange(new Rect(default, target.DesiredSize));
+
+            Assert.Equal(new Rect(default, expectedSize), target.Bounds);
+        }
+
         private class TestTextBlock : TextBlock
         {
             public Size Constraint => _constraint;