From 3ed14edf128af88bc0af74d0ea123fbd728f0142 Mon Sep 17 00:00:00 2001
From: Michael Mayfield <mmayfield45@gmail.com>
Date: Sun, 24 Jan 2016 14:36:10 +0000
Subject: [PATCH 1/2] Fix Grid sizing being broken when using Grid.ColumnSpan.

Caused by CreateMatrices not clearing the existing matrices. This means previous measures alter the results of a measure.
---
 src/Perspex.Controls/Grid.cs                  |  5 ++
 tests/Perspex.Controls.UnitTests/GridTests.cs | 68 +++++++++++++++++++
 .../Perspex.Controls.UnitTests.csproj         |  1 +
 3 files changed, 74 insertions(+)
 create mode 100644 tests/Perspex.Controls.UnitTests/GridTests.cs

diff --git a/src/Perspex.Controls/Grid.cs b/src/Perspex.Controls/Grid.cs
index 1cb80e4221..c2da194441 100644
--- a/src/Perspex.Controls/Grid.cs
+++ b/src/Perspex.Controls/Grid.cs
@@ -587,6 +587,11 @@ namespace Perspex.Controls
                 _rowMatrix = new Segment[rowCount, rowCount];
                 _colMatrix = new Segment[colCount, colCount];
             }
+            else
+            {
+                Array.Clear(_rowMatrix, 0, _rowMatrix.Length);
+                Array.Clear(_colMatrix, 0, _colMatrix.Length);
+            }
         }
 
         private void ExpandStarCols(Size availableSize)
diff --git a/tests/Perspex.Controls.UnitTests/GridTests.cs b/tests/Perspex.Controls.UnitTests/GridTests.cs
new file mode 100644
index 0000000000..af38da5e3e
--- /dev/null
+++ b/tests/Perspex.Controls.UnitTests/GridTests.cs
@@ -0,0 +1,68 @@
+// Copyright (c) The Perspex Project. All rights reserved.
+// Licensed under the MIT license. See licence.md file in the project root for full license information.
+
+using Perspex.Controls;
+using Xunit;
+
+namespace Perspex.Controls.UnitTests
+{
+    public class GridTests
+    {
+        [Fact]
+        public void Calculates_Colspan_Correctly()
+        {
+            var target = new Grid
+            {
+                ColumnDefinitions = new ColumnDefinitions
+                {
+                    new ColumnDefinition(GridLength.Auto),
+                    new ColumnDefinition(new GridLength(4, GridUnitType.Pixel)),
+                    new ColumnDefinition(GridLength.Auto),
+                },
+                RowDefinitions = new RowDefinitions
+                {
+                    new RowDefinition(GridLength.Auto),
+                    new RowDefinition(GridLength.Auto),
+                },
+                Children = new Controls
+                {
+                    new Border
+                    {
+                        Width = 100,
+                        Height = 25,
+                        [Grid.ColumnSpanProperty] = 3,
+                    },
+                    new Border
+                    {
+                        Width = 150,
+                        Height = 25,
+                        [Grid.RowProperty] = 1,
+                    },
+                    new Border
+                    {
+                        Width = 50,
+                        Height = 25,
+                        [Grid.RowProperty] = 1,
+                        [Grid.ColumnProperty] = 2,
+                    }
+                },
+            };
+
+            target.Measure(Size.Infinity);
+
+            // Issue #25 only appears after a second measure
+            target.InvalidateMeasure();
+            target.Measure(Size.Infinity);
+
+            target.Arrange(new Rect(target.DesiredSize));
+
+            Assert.Equal(new Size(204, 50), target.Bounds.Size);
+            Assert.Equal(150d, target.ColumnDefinitions[0].ActualWidth);
+            Assert.Equal(4d, target.ColumnDefinitions[1].ActualWidth);
+            Assert.Equal(50d, target.ColumnDefinitions[2].ActualWidth);
+            Assert.Equal(new Rect(52, 0, 100, 25), target.Children[0].Bounds);
+            Assert.Equal(new Rect(0, 25, 150, 25), target.Children[1].Bounds);
+            Assert.Equal(new Rect(154, 25, 50, 25), target.Children[2].Bounds);
+        }
+    }
+}
diff --git a/tests/Perspex.Controls.UnitTests/Perspex.Controls.UnitTests.csproj b/tests/Perspex.Controls.UnitTests/Perspex.Controls.UnitTests.csproj
index c2535d887e..c4283ef06e 100644
--- a/tests/Perspex.Controls.UnitTests/Perspex.Controls.UnitTests.csproj
+++ b/tests/Perspex.Controls.UnitTests/Perspex.Controls.UnitTests.csproj
@@ -84,6 +84,7 @@
     <Compile Include="ClassesTests.cs" />
     <Compile Include="EnumerableExtensions.cs" />
     <Compile Include="GridSplitterTests.cs" />
+    <Compile Include="GridTests.cs" />
     <Compile Include="HeaderedItemsControlTests .cs" />
     <Compile Include="ControlTests_NameScope.cs" />
     <Compile Include="Generators\ItemContainerGeneratorTests.cs" />

From 928e159aba7a12025244a2a12c7960483931c9d6 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Sun, 24 Jan 2016 16:59:01 +0100
Subject: [PATCH 2/2] Added DesiredSize as a readonly PP.

---
 src/Perspex.Layout/Layoutable.cs | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/Perspex.Layout/Layoutable.cs b/src/Perspex.Layout/Layoutable.cs
index 9930c24614..c804f1a3c7 100644
--- a/src/Perspex.Layout/Layoutable.cs
+++ b/src/Perspex.Layout/Layoutable.cs
@@ -66,6 +66,12 @@ namespace Perspex.Layout
     /// </summary>
     public class Layoutable : Visual, ILayoutable
     {
+        /// <summary>
+        /// Defines the <see cref="DesiredSize"/> property.
+        /// </summary>
+        public static readonly PerspexProperty<Size> DesiredSizeProperty =
+            PerspexProperty.RegisterDirect<Layoutable, Size>(nameof(DesiredSize), o => o.DesiredSize);
+
         /// <summary>
         /// Defines the <see cref="Width"/> property.
         /// </summary>
@@ -249,7 +255,7 @@ namespace Perspex.Layout
         public Size DesiredSize
         {
             get;
-            set;
+            private set;
         }
 
         /// <summary>