Fix issue with FirstColumn when no Row or Column specified in UniformGrid. Add more Unit Tests.

Microsoft.Toolkit.Uwp.UI.Controls/UniformGrid/UniformGrid.Helpers.cs

@@ -64,13 +64,9 @@ namespace Microsoft.Toolkit.Uwp.UI.Controls
         // returns the dimensions of the
         // grid we need to hold all elements.
         #pragma warning disable SA1008 // Opening parenthesis must be spaced correctly
-        internal (int rows, int columns) GetDimensions(ref IEnumerable<FrameworkElement> visible)
+        internal static (int rows, int columns) GetDimensions(ref IEnumerable<FrameworkElement> visible, int rows, int cols, int firstColumn) //// TODO: Switch to 'in' for C# 7.2
         #pragma warning restore SA1008 // Opening parenthesis must be spaced correctly
         {
-            // Make copy of our properties as we don't want to modify.
-            int rows = Rows;
-            int cols = Columns;
-
             // If a dimension isn't specified, we need to figure out the other one (or both).
             if (rows == 0 || cols == 0)
             {
@@ -84,7 +80,7 @@ namespace Microsoft.Toolkit.Uwp.UI.Controls
                     if (cols > 0)
                     {
                         // TODO: Handle RightToLeft?
-                        var first = Math.Min(FirstColumn, cols - 1); // Bound check
+                        var first = Math.Min(firstColumn, cols - 1); // Bound check
 
                         // If we have columns but no rows, calculate rows based on column offset and number of children.
                         rows = (count + first + (cols - 1)) / cols;
@@ -92,7 +88,12 @@ namespace Microsoft.Toolkit.Uwp.UI.Controls
                     }
 
                     // Otherwise, determine square layout if both are zero.
-                    rows = (int)Math.Ceiling(Math.Sqrt(count));
+                    var size = (int)Math.Ceiling(Math.Sqrt(count));
+
+                    // Figure out if firstColumn in bounds
+                    var first2 = Math.Min(firstColumn, size - 1); // Bound check
+
+                    rows = (int)Math.Ceiling(Math.Sqrt(count + first2));
                     return (rows, rows);
                 }
                 else if (cols == 0)
@@ -101,7 +102,7 @@ namespace Microsoft.Toolkit.Uwp.UI.Controls
                     cols = (count + (rows - 1)) / rows;
 
                     // Now that we know a rough size of our shape, see if the FirstColumn effects that:
-                    var first = Math.Min(FirstColumn, cols - 1); // Bound check
+                    var first = Math.Min(firstColumn, cols - 1); // Bound check
 
                     cols = (count + first + (rows - 1)) / rows;
                 }

Microsoft.Toolkit.Uwp.UI.Controls/UniformGrid/UniformGrid.cs

@@ -16,12 +16,14 @@ using Microsoft.Toolkit.Extensions;
 using Windows.Foundation;
 using Windows.UI.Xaml;
 using Windows.UI.Xaml.Controls;
+using Windows.UI.Xaml.Data;
 
 namespace Microsoft.Toolkit.Uwp.UI.Controls
 {
     /// <summary>
     /// The UniformGrid control presents information within a Grid with even spacing.
     /// </summary>
+    [Bindable]
     public partial class UniformGrid : Grid
     {
         /// <summary>
@@ -34,7 +36,7 @@ namespace Microsoft.Toolkit.Uwp.UI.Controls
             // Get all Visible FrameworkElement Children
             var visible = Children.Where(item => item.Visibility != Visibility.Collapsed && item is FrameworkElement).Select(item => item as FrameworkElement);
 
-            var dim = GetDimensions(ref visible);
+            var dim = GetDimensions(ref visible, Rows, Columns, FirstColumn);
 
             // Mark existing dev-defined definitions so we don't erase them.
             foreach (var rd in RowDefinitions)

UnitTests/UI/Controls/Test_UniformGrid.cs

@@ -10,15 +10,19 @@
 // THE CODE OR THE USE OR OTHER DEALINGS IN THE CODE.
 // ******************************************************************
 
-using Microsoft.Toolkit.Extensions;
-using Microsoft.Toolkit.Uwp.UI.Controls;
-using Microsoft.VisualStudio.TestPlatform.UnitTestFramework;
-using Microsoft.VisualStudio.TestPlatform.UnitTestFramework.AppContainer;
 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+using Microsoft.Toolkit.Extensions;
+using Microsoft.Toolkit.Uwp.UI.Extensions;
+using Microsoft.Toolkit.Uwp.UI.Controls;
+using Microsoft.VisualStudio.TestPlatform.UnitTestFramework;
+using Microsoft.VisualStudio.TestPlatform.UnitTestFramework.AppContainer;
+using Windows.Foundation;
+using Windows.UI.Xaml;
+using Windows.UI.Xaml.Markup;
 
 using Assert = Microsoft.VisualStudio.TestPlatform.UnitTestFramework.Assert;
 
@@ -27,6 +31,78 @@ namespace UnitTests.UI.Controls
     [TestClass]
     public class Test_UniformGrid
     {
+        [TestCategory("UniformGrid")]
+        [UITestMethod]
+        public void Test_UniformGrid_GetDimensions_AllVisible()
+        {
+            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"">
+    <controls:UniformGrid x:Name=""UniformGrid"">
+        <Border/>
+        <Border/>
+        <Border/>
+        <Border/>
+        <Border/>
+        <Border/>
+        <Border/>
+        <Border/>
+    </controls:UniformGrid>
+</Page>") as FrameworkElement;
+
+            Assert.IsNotNull(treeroot, "Could not load XAML tree.");
+
+            var grid = treeroot.FindChildByName("UniformGrid") as UniformGrid;
+
+            Assert.IsNotNull(grid, "Could not find UniformGrid in tree.");
+
+            var children = grid.Children.Select(item => item as FrameworkElement);
+
+            Assert.AreEqual(8, grid.Children.Count());
+
+            var dimensions = UniformGrid.GetDimensions(ref children, 0, 0, 0);
+            
+            Assert.AreEqual(3, dimensions.rows);
+            Assert.AreEqual(3, dimensions.columns);
+        }
+
+        [TestCategory("UniformGrid")]
+        [UITestMethod]
+        public void Test_UniformGrid_GetDimensions_FirstColumn()
+        {
+            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"">
+    <controls:UniformGrid x:Name=""UniformGrid"">
+        <Border/>
+        <Border/>
+        <Border/>
+        <Border/>
+        <Border/>
+        <Border/>
+        <Border/>
+        <Border/>
+    </controls:UniformGrid>
+</Page>") as FrameworkElement;
+
+            Assert.IsNotNull(treeroot, "Could not load XAML tree.");
+
+            var grid = treeroot.FindChildByName("UniformGrid") as UniformGrid;
+
+            Assert.IsNotNull(grid, "Could not find UniformGrid in tree.");
+
+            var children = grid.Children.Select(item => item as FrameworkElement);
+
+            Assert.AreEqual(8, grid.Children.Count());
+
+            var dimensions = UniformGrid.GetDimensions(ref children, 0, 0, 2);
+
+            Assert.AreEqual(4, dimensions.rows);
+            Assert.AreEqual(4, dimensions.columns);
+        }
+
         [TestCategory("UniformGrid")]
         [UITestMethod]
         public void Test_UniformGrid_GetFreeSpots_Basic()

UnitTests/UnitTestApp.xaml.cs

@@ -23,7 +23,7 @@ namespace UnitTests
     /// <summary>
     /// Provides application-specific behavior to supplement the default Application class.
     /// </summary>
-    internal sealed partial class App : Application
+    public sealed partial class App : Application
     {
         /// <summary>
         /// Initializes a new instance of the <see cref="App"/> class.