From 67e6b2eaed82bcf4b49b62038a004684891cf8b2 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Tue, 5 May 2015 23:25:55 +0200
Subject: [PATCH] Fixed ScrollPresenter arrange.

And added tests because I think it's about the 5th time I've tried to
get this right...
---
 .../Presenters/ScrollContentPresenter.cs      |   2 +-
 .../ScrollContentPresenterTests.cs            | 135 ++++++++++++++++++
 .../ScrollViewerTests.cs                      |   1 +
 3 files changed, 137 insertions(+), 1 deletion(-)

diff --git a/Perspex.Controls/Presenters/ScrollContentPresenter.cs b/Perspex.Controls/Presenters/ScrollContentPresenter.cs
index 3baef37e6a..e92f5f846b 100644
--- a/Perspex.Controls/Presenters/ScrollContentPresenter.cs
+++ b/Perspex.Controls/Presenters/ScrollContentPresenter.cs
@@ -95,7 +95,7 @@ namespace Perspex.Controls.Presenters
 
             if (child != null)
             {
-                child.Arrange(new Rect((Point)(-this.Offset), child.DesiredSize));
+                child.Arrange(new Rect((Point)(-this.Offset), finalSize));
                 return finalSize;
             }
 
diff --git a/Tests/Perspex.Controls.UnitTests/ScrollContentPresenterTests.cs b/Tests/Perspex.Controls.UnitTests/ScrollContentPresenterTests.cs
index 0e358560a6..b0822ba872 100644
--- a/Tests/Perspex.Controls.UnitTests/ScrollContentPresenterTests.cs
+++ b/Tests/Perspex.Controls.UnitTests/ScrollContentPresenterTests.cs
@@ -11,9 +11,144 @@ namespace Perspex.Controls.UnitTests
     using System.Reactive.Linq;
     using Perspex.Controls.Presenters;
     using Xunit;
+    using Perspex.Layout;
 
     public class ScrollContentPresenterTests
     {
+        [Fact]
+        public void Content_Can_Be_Left_Aligned()
+        {
+            Border content;
+            var target = new ScrollContentPresenter
+            {
+                Content = (content = new Border
+                {
+                    Padding = new Thickness(8),
+                    HorizontalAlignment = HorizontalAlignment.Left
+                }),
+            };
+
+            target.Measure(new Size(100, 100));
+            target.Arrange(new Rect(0, 0, 100, 100));
+
+            Assert.Equal(new Rect(0, 0, 16, 100), content.Bounds);
+        }
+
+        [Fact]
+        public void Content_Can_Be_Stretched()
+        {
+            Border content;
+            var target = new ScrollContentPresenter
+            {
+                Content = (content = new Border
+                {
+                    Padding = new Thickness(8),
+                }),
+            };
+
+            target.Measure(new Size(100, 100));
+            target.Arrange(new Rect(0, 0, 100, 100));
+
+            Assert.Equal(new Rect(0, 0, 100, 100), content.Bounds);
+        }
+
+        [Fact]
+        public void Content_Can_Be_Right_Aligned()
+        {
+            Border content;
+            var target = new ScrollContentPresenter
+            {
+                Content = (content = new Border
+                {
+                    Padding = new Thickness(8),
+                    HorizontalAlignment = HorizontalAlignment.Right
+                }),
+            };
+
+            target.Measure(new Size(100, 100));
+            target.Arrange(new Rect(0, 0, 100, 100));
+
+            Assert.Equal(new Rect(84, 0, 16, 100), content.Bounds);
+        }
+
+        [Fact]
+        public void Content_Can_Be_Bottom_Aligned()
+        {
+            Border content;
+            var target = new ScrollContentPresenter
+            {
+                Content = (content = new Border
+                {
+                    Padding = new Thickness(8),
+                    VerticalAlignment = VerticalAlignment.Bottom,
+                }),
+            };
+
+            target.Measure(new Size(100, 100));
+            target.Arrange(new Rect(0, 0, 100, 100));
+
+            Assert.Equal(new Rect(0, 84, 100, 16), content.Bounds);
+        }
+
+        [Fact]
+        public void Content_Can_Be_TopRight_Aligned()
+        {
+            Border content;
+            var target = new ScrollContentPresenter
+            {
+                Content = (content = new Border
+                {
+                    Padding = new Thickness(8),
+                    HorizontalAlignment = HorizontalAlignment.Right,
+                    VerticalAlignment = VerticalAlignment.Top,
+                }),
+            };
+
+            target.Measure(new Size(100, 100));
+            target.Arrange(new Rect(0, 0, 100, 100));
+
+            Assert.Equal(new Rect(84, 0, 16, 16), content.Bounds);
+        }
+
+        [Fact]
+        public void Content_Can_Be_Larger_Than_Viewport()
+        {
+            Border content;
+            var target = new ScrollContentPresenter
+            {
+                Content = (content = new Border
+                {
+                    Width = 150,
+                    Height = 150,
+                }),
+            };
+
+            target.Measure(new Size(100, 100));
+            target.Arrange(new Rect(0, 0, 100, 100));
+
+            Assert.Equal(new Rect(0, 0, 150, 150), content.Bounds);
+        }
+
+        [Fact]
+        public void Content_Can_Be_Offset()
+        {
+            Border content;
+            var target = new ScrollContentPresenter
+            {
+                Content = (content = new Border
+                {
+                    Width = 150,
+                    Height = 150,
+                }),
+                Offset = new Vector(25, 25),
+            };
+
+            target.Measure(new Size(100, 100));
+            target.Arrange(new Rect(0, 0, 100, 100));
+
+            Assert.Equal(new Rect(-25, -25, 150, 150), content.Bounds);
+        }
+
         [Fact]
         public void Arrange_Should_Set_Viewport_And_Extent_In_That_Order()
         {
diff --git a/Tests/Perspex.Controls.UnitTests/ScrollViewerTests.cs b/Tests/Perspex.Controls.UnitTests/ScrollViewerTests.cs
index 6a494577c8..deccb37246 100644
--- a/Tests/Perspex.Controls.UnitTests/ScrollViewerTests.cs
+++ b/Tests/Perspex.Controls.UnitTests/ScrollViewerTests.cs
@@ -13,6 +13,7 @@ namespace Perspex.Controls.UnitTests
     using Perspex.Controls.Templates;
     using Perspex.VisualTree;
     using Xunit;
+    using Perspex.Layout;
 
     public class ScrollViewerTests
     {