Merge pull request #8482 from AvaloniaUI/fixes/window-centering-edge-case

window centering edge case

src/Avalonia.Controls/Window.cs

@@ -682,8 +682,8 @@ namespace Avalonia.Controls
             IsVisible = true;
 
             var initialSize = new Size(
-                double.IsNaN(Width) ? ClientSize.Width : Width,
-                double.IsNaN(Height) ? ClientSize.Height : Height);
+                double.IsNaN(Width) ? Math.Max(MinWidth, ClientSize.Width) : Width,
+                double.IsNaN(Height) ? Math.Max(MinHeight, ClientSize.Height) : Height);
 
             if (initialSize != ClientSize)
             {

tests/Avalonia.Controls.UnitTests/WindowTests.cs

@@ -540,6 +540,33 @@ namespace Avalonia.Controls.UnitTests
                 Assert.Equal(window.Position, expectedPosition);
             }
         }
+        
+        [Fact]
+        public void Window_Should_Be_Sized_To_MinSize_If_InitialSize_Less_Than_MinSize()
+        {
+            var screen1 = new Mock<Screen>(1.75, new PixelRect(new PixelSize(1920, 1080)), new PixelRect(new PixelSize(1920, 966)), true);
+            var screens = new Mock<IScreenImpl>();
+            screens.Setup(x => x.AllScreens).Returns(new Screen[] { screen1.Object });
+            screens.Setup(x => x.ScreenFromPoint(It.IsAny<PixelPoint>())).Returns(screen1.Object);
+            
+            var windowImpl = MockWindowingPlatform.CreateWindowMock(400, 300);
+            windowImpl.Setup(x => x.DesktopScaling).Returns(1.75);
+            windowImpl.Setup(x => x.RenderScaling).Returns(1.75);
+            windowImpl.Setup(x => x.Screen).Returns(screens.Object);
+            
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var window = new Window(windowImpl.Object);
+                window.WindowStartupLocation = WindowStartupLocation.CenterScreen;
+                window.MinWidth = 720;
+                window.MinHeight = 480;
+
+                window.Show();
+                
+                Assert.Equal(new PixelPoint(330, 63), window.Position);
+                Assert.Equal(new Size(720, 480), window.Bounds.Size);
+            }
+        }
 
         [Fact]
         public void Window_Should_Be_Centered_Relative_To_Owner_When_WindowStartupLocation_Is_CenterOwner()

tests/Avalonia.UnitTests/MockWindowingPlatform.cs

@@ -21,11 +21,11 @@ namespace Avalonia.UnitTests
             _popupImpl = popupImpl;
         }
 
-        public static Mock<IWindowImpl> CreateWindowMock()
+        public static Mock<IWindowImpl> CreateWindowMock(double initialWidth = 800, double initialHeight = 600)
         {
             var windowImpl = new Mock<IWindowImpl>();
             var position = new PixelPoint();
-            var clientSize = new Size(800, 600);
+            var clientSize = new Size(initialWidth,  initialHeight);
 
             windowImpl.SetupAllProperties();
             windowImpl.Setup(x => x.ClientSize).Returns(() => clientSize);
@@ -55,12 +55,18 @@ namespace Avalonia.UnitTests
             windowImpl.Setup(x => x.Resize(It.IsAny<Size>(), It.IsAny<PlatformResizeReason>()))
                 .Callback<Size, PlatformResizeReason>((x, y) =>
             {
-                clientSize = x.Constrain(s_screenSize);
-                windowImpl.Object.Resized?.Invoke(clientSize, y);
+                var constrainedSize = x.Constrain(s_screenSize);
+                
+                if (constrainedSize != clientSize)
+                {
+                    clientSize = constrainedSize;
+                    windowImpl.Object.Resized?.Invoke(clientSize, y);
+                }
             });
 
             windowImpl.Setup(x => x.Show(true, It.IsAny<bool>())).Callback(() =>
             {
+                windowImpl.Object.Resized?.Invoke(windowImpl.Object.ClientSize, PlatformResizeReason.Unspecified);
                 windowImpl.Object.Activated?.Invoke();
             });