Started adding ScrollContentPresenter tests.

Perspex.Controls/Presenters/ScrollContentPresenter.cs

@@ -26,6 +26,8 @@ namespace Perspex.Controls.Presenters
         public static readonly PerspexProperty<bool> CanScrollHorizontallyProperty =
             PerspexProperty.Register<ScrollContentPresenter, bool>("CanScrollHorizontally", true);
 
+        private Size measuredExtent;
+
         static ScrollContentPresenter()
         {
             ClipToBoundsProperty.OverrideDefaultValue(typeof(ScrollContentPresenter), true);
@@ -77,7 +79,7 @@ namespace Perspex.Controls.Presenters
 
                 content.Measure(measureSize);
                 var size = content.DesiredSize.Value;
-                this.Extent = size;
+                this.measuredExtent = size;
                 return size.Constrain(availableSize);
             }
             else
@@ -91,6 +93,7 @@ namespace Perspex.Controls.Presenters
             var child = this.GetVisualChildren().SingleOrDefault() as ILayoutable;
 
             this.Viewport = finalSize;
+            this.Extent = this.measuredExtent;
 
             if (child != null)
             {

Tests/Perspex.Controls.UnitTests/Perspex.Controls.UnitTests.csproj

@@ -51,6 +51,21 @@
       <HintPath>..\..\packages\Splat.1.5.1\lib\Net45\Splat.dll</HintPath>
     </Reference>
     <Reference Include="System" />
+    <Reference Include="System.Reactive.Core, Version=2.2.5.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
+      <SpecificVersion>False</SpecificVersion>
+      <HintPath>..\..\packages\Rx-Core.2.2.5\lib\net45\System.Reactive.Core.dll</HintPath>
+    </Reference>
+    <Reference Include="System.Reactive.Interfaces, Version=2.2.5.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
+      <SpecificVersion>False</SpecificVersion>
+      <HintPath>..\..\packages\Rx-Interfaces.2.2.5\lib\net45\System.Reactive.Interfaces.dll</HintPath>
+    </Reference>
+    <Reference Include="System.Reactive.Linq, Version=2.2.5.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
+      <SpecificVersion>False</SpecificVersion>
+      <HintPath>..\..\packages\Rx-Linq.2.2.5\lib\net45\System.Reactive.Linq.dll</HintPath>
+    </Reference>
+    <Reference Include="System.Reactive.PlatformServices">
+      <HintPath>..\..\packages\Rx-PlatformServices.2.2.5\lib\net45\System.Reactive.PlatformServices.dll</HintPath>
+    </Reference>
     <Reference Include="xunit">
       <HintPath>..\..\packages\xunit.1.9.2\lib\net20\xunit.dll</HintPath>
     </Reference>
@@ -65,6 +80,7 @@
   </Choose>
   <ItemGroup>
     <Compile Include="DropDownTests.cs" />
+    <Compile Include="ScrollContentPresenterTests.cs" />
     <Compile Include="ScrollViewerTests.cs" />
     <Compile Include="SelectingItemsControlTests.cs" />
     <Compile Include="ListBoxTests.cs" />

Tests/Perspex.Controls.UnitTests/ScrollContentPresenterTests.cs

@@ -0,0 +1,53 @@
+// -----------------------------------------------------------------------
+// <copyright file="ScrollPresenterTests.cs" company="Steven Kirk">
+// Copyright 2014 MIT Licence. See licence.md for more information.
+// </copyright>
+// -----------------------------------------------------------------------
+
+namespace Perspex.Controls.UnitTests
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Reactive.Linq;
+    using Perspex.Controls.Presenters;
+    using Xunit;
+
+    public class ScrollContentPresenterTests
+    {
+        [Fact]
+        public void Arrange_Should_Set_Viewport_And_Extent_In_That_Order()
+        {
+            var target = new ScrollContentPresenter
+            {
+                Content = new Border { Width = 40, Height = 50 }
+            };
+
+            var set = new List<string>();
+
+            target.Measure(new Size(100, 100));
+
+            target.GetObservable(ScrollViewer.ViewportProperty).Skip(1).Subscribe(_ => set.Add("Viewport"));
+            target.GetObservable(ScrollViewer.ExtentProperty).Skip(1).Subscribe(_ => set.Add("Extent"));
+
+            target.Arrange(new Rect(0, 0, 100, 100));
+
+            Assert.Equal(new[] { "Viewport", "Extent" }, set);
+        }
+
+        [Fact]
+        public void Setting_Offset_Should_Invalidate_Arrange()
+        {
+            var target = new ScrollContentPresenter
+            {
+                Content = new Border { Width = 40, Height = 50 }
+            };
+
+            target.Measure(new Size(100, 100));
+            target.Arrange(new Rect(0, 0, 100, 100));
+            target.Offset = new Vector(10, 100);
+
+            Assert.True(target.IsMeasureValid);
+            Assert.False(target.IsArrangeValid);
+        }
+    }
+}

Tests/Perspex.Controls.UnitTests/packages.config

@@ -3,6 +3,11 @@
   <package id="AutoFixture" version="3.21.1" targetFramework="net45" />
   <package id="AutoFixture.AutoMoq" version="3.21.1" targetFramework="net45" />
   <package id="Moq" version="4.2.1409.1722" targetFramework="net45" />
+  <package id="Rx-Core" version="2.2.5" targetFramework="net45" />
+  <package id="Rx-Interfaces" version="2.2.5" targetFramework="net45" />
+  <package id="Rx-Linq" version="2.2.5" targetFramework="net45" />
+  <package id="Rx-Main" version="2.2.5" targetFramework="net45" />
+  <package id="Rx-PlatformServices" version="2.2.5" targetFramework="net45" />
   <package id="Splat" version="1.5.1" targetFramework="net45" />
   <package id="xunit" version="1.9.2" targetFramework="net45" />
   <package id="xunit.runner.visualstudio" version="2.0.0-rc1-build1030" targetFramework="net45" />