Add last set of tests for ConstrainedBox for Alignment positioning within a parent for completeness.

Author: michael-hawker

UnitTests/UnitTests.UWP/UI/Controls/Test_ConstrainedBox.Alignment.cs

@@ -0,0 +1,88 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.Toolkit.Uwp;
+using Microsoft.Toolkit.Uwp.UI;
+using Microsoft.Toolkit.Uwp.UI.Controls;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Microsoft.VisualStudio.TestTools.UnitTesting.AppContainer;
+using Windows.Foundation;
+using Windows.UI.Xaml;
+using Windows.UI.Xaml.Controls;
+using Windows.UI.Xaml.Markup;
+
+namespace UnitTests.UWP.UI.Controls
+{
+    /// <summary>
+    /// These tests check whether the inner alignment of the box within it's parent works as expected.
+    /// </summary>
+    public partial class Test_ConstrainedBox : VisualUITestBase
+    {
+        // For this test we're testing within the confines of a 200x200 box to position a contrained
+        // 50x100 element in all the different alignment combinations.
+        [TestCategory("ConstrainedBox")]
+        [TestMethod]
+        [DataRow("Left", 0, "Center", 50, DisplayName = "LeftCenter")]
+        [DataRow("Left", 0, "Top", 0, DisplayName = "LeftTop")]
+        [DataRow("Center", 75, "Top", 0, DisplayName = "CenterTop")]
+        [DataRow("Right", 150, "Top", 0, DisplayName = "RightTop")]
+        [DataRow("Right", 150, "Center", 50, DisplayName = "RightCenter")]
+        [DataRow("Right", 150, "Bottom", 100, DisplayName = "RightBottom")]
+        [DataRow("Center", 75, "Bottom", 100, DisplayName = "CenterBottom")]
+        [DataRow("Left", 0, "Bottom", 100, DisplayName = "LeftBottom")]
+        [DataRow("Center", 75, "Center", 50, DisplayName = "CenterCenter")]
+        public async Task Test_ConstrainedBox_Alignment_Aspect(string horizontalAlignment, int expectedLeft, string verticalAlignment, int expectedTop)
+        {
+            await App.DispatcherQueue.EnqueueAsync(async () =>
+            {
+                var treeRoot = XamlReader.Load(@$"<Page
+    xmlns=""http://schemas.microsoft.com/winfx/2006/xaml/presentation""
+    xmlns:x=""http://schemas.microsoft.com/winfx/2006/xaml""
+    xmlns:controls=""using:Microsoft.Toolkit.Uwp.UI.Controls"">
+    <Grid x:Name=""ParentGrid""
+          Width=""200"" Height=""200"">
+      <controls:ConstrainedBox x:Name=""ConstrainedBox"" AspectRatio=""1:2"" MaxHeight=""100""
+                               HorizontalAlignment=""{horizontalAlignment}""
+                               VerticalAlignment=""{verticalAlignment}"">
+        <Border HorizontalAlignment=""Stretch"" VerticalAlignment=""Stretch"" Background=""Red""/>
+      </controls:ConstrainedBox>
+    </Grid>
+</Page>") as FrameworkElement;
+
+                Assert.IsNotNull(treeRoot, "Could not load XAML tree.");
+
+                // Initialize Visual Tree
+                await SetTestContentAsync(treeRoot);
+
+                var grid = treeRoot.FindChild("ParentGrid") as Grid;
+
+                Assert.IsNotNull(grid, "Could not find the ParentGrid in tree.");
+
+                var panel = treeRoot.FindChild("ConstrainedBox") as ConstrainedBox;
+
+                Assert.IsNotNull(panel, "Could not find ConstrainedBox in tree.");
+
+                // Force Layout calculations
+                panel.UpdateLayout();
+
+                var child = panel.Content as Border;
+
+                Assert.IsNotNull(child, "Could not find inner Border");
+
+                // Check Size
+                Assert.AreEqual(50, child.ActualWidth, 0.01, "Actual width does not meet expected value of 50");
+                Assert.AreEqual(100, child.ActualHeight, 0.01, "Actual height does not meet expected value of 100");
+
+                // Check inner Positioning, we do this from the Grid as the ConstainedBox also modifies its own size
+                // and is hugging the child.
+                var position = grid.CoordinatesTo(child);
+
+                Assert.AreEqual(expectedLeft, position.X, 0.01, "X position does not meet expected value of 0");
+                Assert.AreEqual(expectedTop, position.Y, 0.01, "Y position does not meet expected value of 50");
+            });
+        }
+    }
+}

UnitTests/UnitTests.UWP/UI/Controls/Test_ConstrainedBox.Constrict.cs

@@ -29,10 +29,6 @@ public async Task Test_ConstrainedBox_Constrain_AspectMaxHeight()
         {
             await App.DispatcherQueue.EnqueueAsync(async () =>
             {
-                // Even though we constrain the size of the ScrollViewer, it initially reports infinite measure
-                // which is what we want to test. We constrain the dimension so that we have a specific value
-                // that we can measure against. If we instead restrained the inner Border, it'd just set
-                // it's side within the constrained space of the parent layout...
                 var treeRoot = XamlReader.Load(@"<Page
     xmlns=""http://schemas.microsoft.com/winfx/2006/xaml/presentation""
     xmlns:x=""http://schemas.microsoft.com/winfx/2006/xaml""

UnitTests/UnitTests.UWP/UnitTests.UWP.csproj

@@ -229,6 +229,7 @@
     <Compile Include="UI\Collection\Test_IncrementalLoadingCollection.cs" />
     <Compile Include="UI\Controls\Test_Carousel.cs" />
     <Compile Include="UI\Controls\Test_BladeView.cs" />
+    <Compile Include="UI\Controls\Test_ConstrainedBox.Alignment.cs" />
     <Compile Include="UI\Controls\Test_ConstrainedBox.Constrict.cs" />
     <Compile Include="UI\Controls\Test_ConstrainedBox.Infinity.cs" />
     <Compile Include="UI\Controls\Test_ConstrainedBox.AspectRatio.cs" />