From d9ca27ba876b3043b8bcf4aab521ece02c005efe Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Sun, 6 May 2018 01:22:49 +0200
Subject: [PATCH 01/24] Stop renderer on Window minimize.

Adds a new `WindowStateChanged` event to `IWindowImpl` and when a window is minimized, stops the associated renderer (only implemented on win32 currently).
---
 src/Avalonia.Controls/Platform/IWindowImpl.cs |  5 ++++
 src/Avalonia.Controls/Window.cs               | 13 ++++++++++
 .../Remote/PreviewerWindowImpl.cs             |  1 +
 src/Avalonia.DesignerSupport/Remote/Stubs.cs  |  2 ++
 src/Gtk/Avalonia.Gtk3/WindowImpl.cs           |  4 +++-
 src/OSX/Avalonia.MonoMac/WindowImpl.cs        |  2 ++
 .../Interop/UnmanagedMethods.cs               | 24 +++++++++++++++++++
 src/Windows/Avalonia.Win32/WindowImpl.cs      | 21 ++++++++++++++++
 8 files changed, 71 insertions(+), 1 deletion(-)

diff --git a/src/Avalonia.Controls/Platform/IWindowImpl.cs b/src/Avalonia.Controls/Platform/IWindowImpl.cs
index 3f2c977718..c5d632c0f7 100644
--- a/src/Avalonia.Controls/Platform/IWindowImpl.cs
+++ b/src/Avalonia.Controls/Platform/IWindowImpl.cs
@@ -16,6 +16,11 @@ namespace Avalonia.Platform
         /// </summary>
         WindowState WindowState { get; set; }
 
+        /// <summary>
+        /// Gets or sets a method called when the <see cref="WindowState"/> changes.
+        /// </summary>
+        Action<WindowState> WindowStateChanged { get; set; }
+
         /// <summary>
         /// Sets the title of the window.
         /// </summary>
diff --git a/src/Avalonia.Controls/Window.cs b/src/Avalonia.Controls/Window.cs
index 16ee3a46b3..6814b8567e 100644
--- a/src/Avalonia.Controls/Window.cs
+++ b/src/Avalonia.Controls/Window.cs
@@ -136,6 +136,7 @@ namespace Avalonia.Controls
             : base(impl)
         {
             impl.Closing = HandleClosing;
+            impl.WindowStateChanged = HandleWindowStateChanged;
             _maxPlatformClientSize = PlatformImpl?.MaxClientSize ?? default(Size);
             Screens = new Screens(PlatformImpl?.Screen);
         }
@@ -308,6 +309,18 @@ namespace Avalonia.Controls
             return args.Cancel;
         }
 
+        protected virtual void HandleWindowStateChanged(WindowState state)
+        {
+            if (state == WindowState.Minimized)
+            {
+                Renderer.Stop();
+            }
+            else if (state == WindowState.Normal)
+            {
+                Renderer.Start();
+            }
+        }
+
         /// <summary>
         /// Hides the window but does not close it.
         /// </summary>
diff --git a/src/Avalonia.DesignerSupport/Remote/PreviewerWindowImpl.cs b/src/Avalonia.DesignerSupport/Remote/PreviewerWindowImpl.cs
index 9750b46aa2..ef16d06b60 100644
--- a/src/Avalonia.DesignerSupport/Remote/PreviewerWindowImpl.cs
+++ b/src/Avalonia.DesignerSupport/Remote/PreviewerWindowImpl.cs
@@ -42,6 +42,7 @@ namespace Avalonia.DesignerSupport.Remote
         public Func<bool> Closing { get; set; }
         public IPlatformHandle Handle { get; }
         public WindowState WindowState { get; set; }
+        public Action<WindowState> WindowStateChanged { get; set; }
         public Size MaxClientSize { get; } = new Size(4096, 4096);
         public event Action LostFocus;
 
diff --git a/src/Avalonia.DesignerSupport/Remote/Stubs.cs b/src/Avalonia.DesignerSupport/Remote/Stubs.cs
index ee8569d748..72fce0d921 100644
--- a/src/Avalonia.DesignerSupport/Remote/Stubs.cs
+++ b/src/Avalonia.DesignerSupport/Remote/Stubs.cs
@@ -32,6 +32,8 @@ namespace Avalonia.DesignerSupport.Remote
         public Point Position { get; set; }
         public Action<Point> PositionChanged { get; set; }
         public WindowState WindowState { get; set; }
+        public Action<WindowState> WindowStateChanged { get; set; }
+
         public IRenderer CreateRenderer(IRenderRoot root) => new ImmediateRenderer(root);
         public void Dispose()
         {
diff --git a/src/Gtk/Avalonia.Gtk3/WindowImpl.cs b/src/Gtk/Avalonia.Gtk3/WindowImpl.cs
index 2d309e19d4..ac03816b02 100644
--- a/src/Gtk/Avalonia.Gtk3/WindowImpl.cs
+++ b/src/Gtk/Avalonia.Gtk3/WindowImpl.cs
@@ -43,7 +43,9 @@ namespace Avalonia.Gtk3
                 }
             }
         }
-        
+
+        public Action<WindowState> WindowStateChanged { get; set; }
+
         public IDisposable ShowDialog()
         {
             Native.GtkWindowSetModal(GtkWidget, true);
diff --git a/src/OSX/Avalonia.MonoMac/WindowImpl.cs b/src/OSX/Avalonia.MonoMac/WindowImpl.cs
index d01cbd6ae3..43d6918112 100644
--- a/src/OSX/Avalonia.MonoMac/WindowImpl.cs
+++ b/src/OSX/Avalonia.MonoMac/WindowImpl.cs
@@ -49,6 +49,8 @@ namespace Avalonia.MonoMac
             }
         }
 
+        public Action<WindowState> WindowStateChanged { get; set; }
+
         bool IsZoomed => IsDecorated ? Window.IsZoomed : UndecoratedIsMaximized;
 
         public bool UndecoratedIsMaximized => Window.Frame == Window.Screen.VisibleFrame;
diff --git a/src/Windows/Avalonia.Win32/Interop/UnmanagedMethods.cs b/src/Windows/Avalonia.Win32/Interop/UnmanagedMethods.cs
index 5c24aa1c69..fef0ef747d 100644
--- a/src/Windows/Avalonia.Win32/Interop/UnmanagedMethods.cs
+++ b/src/Windows/Avalonia.Win32/Interop/UnmanagedMethods.cs
@@ -104,6 +104,30 @@ namespace Avalonia.Win32.Interop
             ForceMinimize = 11
         }
 
+        public enum SysCommands
+        {
+            SC_SIZE = 0xF000,
+            SC_MOVE = 0xF010,
+            SC_MINIMIZE = 0xF020,
+            SC_MAXIMIZE = 0xF030,
+            SC_NEXTWINDOW = 0xF040,
+            SC_PREVWINDOW = 0xF050,
+            SC_CLOSE = 0xF060,
+            SC_VSCROLL = 0xF070,
+            SC_HSCROLL = 0xF080,
+            SC_MOUSEMENU = 0xF090,
+            SC_KEYMENU = 0xF100,
+            SC_ARRANGE = 0xF110,
+            SC_RESTORE = 0xF120,
+            SC_TASKLIST = 0xF130,
+            SC_SCREENSAVE = 0xF140,
+            SC_HOTKEY = 0xF150,
+            SC_DEFAULT = 0xF160,
+            SC_MONITORPOWER = 0xF170,
+            SC_CONTEXTHELP = 0xF180,
+            SC_SEPARATOR = 0xF00F,
+        }
+
         public enum SystemMetric
         {
             SM_CXSCREEN = 0,  // 0x00
diff --git a/src/Windows/Avalonia.Win32/WindowImpl.cs b/src/Windows/Avalonia.Win32/WindowImpl.cs
index cf6cb40e58..399a09ea6c 100644
--- a/src/Windows/Avalonia.Win32/WindowImpl.cs
+++ b/src/Windows/Avalonia.Win32/WindowImpl.cs
@@ -77,6 +77,8 @@ namespace Avalonia.Win32
 
         public Action<Point> PositionChanged { get; set; }
 
+        public Action<WindowState> WindowStateChanged { get; set; }
+
         public Thickness BorderThickness
         {
             get
@@ -627,6 +629,25 @@ namespace Avalonia.Win32
 
                     return IntPtr.Zero;
 
+                case UnmanagedMethods.WindowsMessage.WM_SYSCOMMAND:
+                    if (WindowStateChanged != null)
+                    {
+                        switch ((SysCommands)wParam)
+                        {
+                            case SysCommands.SC_MINIMIZE:
+                                WindowStateChanged(WindowState.Minimized);
+                                break;
+                            case SysCommands.SC_MAXIMIZE:
+                                WindowStateChanged(WindowState.Maximized);
+                                break;
+                            case SysCommands.SC_RESTORE:
+                                WindowStateChanged(WindowState.Normal);
+                                break;
+                        }
+                    }
+
+                    break;
+
                 case UnmanagedMethods.WindowsMessage.WM_MOVE:
                     PositionChanged?.Invoke(new Point((short)(ToInt32(lParam) & 0xffff), (short)(ToInt32(lParam) >> 16)));
                     return IntPtr.Zero;

From b3c0301ee0dce92152b6573aa8e88bade41be71e Mon Sep 17 00:00:00 2001
From: Jeremy Koritzinsky <jkoritzinsky@gmail.com>
Date: Tue, 29 May 2018 14:47:54 -0500
Subject: [PATCH 02/24] Add missing annotations dependency.

---
 packages.cake | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/packages.cake b/packages.cake
index bcb135f6ad..7e7e722c82 100644
--- a/packages.cake
+++ b/packages.cake
@@ -120,6 +120,7 @@ public class Packages
         var SharpDXDirect3D11Version = packageVersions["SharpDX.Direct3D11"].FirstOrDefault().Item1;
         var SharpDXDirect3D9Version = packageVersions["SharpDX.Direct3D9"].FirstOrDefault().Item1;
         var SharpDXDXGIVersion = packageVersions["SharpDX.DXGI"].FirstOrDefault().Item1;
+        var SystemComponentModelAnnotationsVersion = packageVersions["System.ComponentModel.Annotations"].FirstOrDefault().Item1;
 
         context.Information("Package: Serilog, version: {0}", SerilogVersion);
         context.Information("Package: Sprache, version: {0}", SpracheVersion);
@@ -238,6 +239,7 @@ public class Packages
                     new NuSpecDependency() { Id = "Sprache", Version = SpracheVersion },
                     new NuSpecDependency() { Id = "System.Reactive", Version = SystemReactiveVersion },
                     new NuSpecDependency() { Id = "Avalonia.Remote.Protocol", Version = parameters.Version },
+                    new NuSpecDependency() { Id = "System.ComponentModel.Annotations", Version = SystemComponentModelAnnotationsVersion },
                     //.NET Core
                     new NuSpecDependency() { Id = "System.Threading.ThreadPool", TargetFramework = "netcoreapp2.0", Version = "4.3.0" },
                     new NuSpecDependency() { Id = "Microsoft.Extensions.DependencyModel", TargetFramework = "netcoreapp2.0", Version = "1.1.0" },

From 4eec8b42715233343e13bb403f204b56a78c304e Mon Sep 17 00:00:00 2001
From: Jeremy Koritzinsky <jkoritzinsky@gmail.com>
Date: Tue, 29 May 2018 15:14:52 -0500
Subject: [PATCH 03/24] Fix #1531 by making IStyle an IAvaloniaObject.

---
 src/Avalonia.Controls/Design.cs        | 18 +++++++-----------
 src/Avalonia.Styling/Styling/IStyle.cs |  2 +-
 src/Avalonia.Styling/Styling/Style.cs  |  2 +-
 3 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/src/Avalonia.Controls/Design.cs b/src/Avalonia.Controls/Design.cs
index ce52891749..3a67e554ac 100644
--- a/src/Avalonia.Controls/Design.cs
+++ b/src/Avalonia.Controls/Design.cs
@@ -1,5 +1,6 @@
 
 using System.Runtime.CompilerServices;
+using Avalonia.Styling;
 
 namespace Avalonia.Controls
 {
@@ -45,23 +46,18 @@ namespace Avalonia.Controls
         {
             return control.GetValue(DataContextProperty);
         }
-
-        static readonly ConditionalWeakTable<object, Control> Substitutes = new ConditionalWeakTable<object, Control>();
-
+        
         public static readonly AttachedProperty<Control> PreviewWithProperty = AvaloniaProperty
-            .RegisterAttached<AvaloniaObject, Control>("PreviewWith", typeof (Design));
+            .RegisterAttached<IStyle, Control>("PreviewWith", typeof (Design));
 
-        public static void SetPreviewWith(object target, Control control)
+        public static void SetPreviewWith(IStyle target, Control control)
         {
-            Substitutes.Remove(target);
-            Substitutes.Add(target, control);
+            target.SetValue(PreviewWithProperty, control);
         }
 
-        public static Control GetPreviewWith(object target)
+        public static Control GetPreviewWith(IStyle target)
         {
-            Control rv;
-            Substitutes.TryGetValue(target, out rv);
-            return rv;
+            return target.GetValue(PreviewWithProperty);
         }
 
         public static void ApplyDesignModeProperties(Control target, Control source)
diff --git a/src/Avalonia.Styling/Styling/IStyle.cs b/src/Avalonia.Styling/Styling/IStyle.cs
index 5f12763825..2ce06cc36c 100644
--- a/src/Avalonia.Styling/Styling/IStyle.cs
+++ b/src/Avalonia.Styling/Styling/IStyle.cs
@@ -8,7 +8,7 @@ namespace Avalonia.Styling
     /// <summary>
     /// Defines the interface for styles.
     /// </summary>
-    public interface IStyle : IResourceNode
+    public interface IStyle : IAvaloniaObject, IResourceNode
     {
         /// <summary>
         /// Attaches the style to a control if the style's selector matches.
diff --git a/src/Avalonia.Styling/Styling/Style.cs b/src/Avalonia.Styling/Styling/Style.cs
index 88ff695ba2..203f679683 100644
--- a/src/Avalonia.Styling/Styling/Style.cs
+++ b/src/Avalonia.Styling/Styling/Style.cs
@@ -15,7 +15,7 @@ namespace Avalonia.Styling
     /// <summary>
     /// Defines a style.
     /// </summary>
-    public class Style : IStyle, ISetStyleParent
+    public class Style : AvaloniaObject, IStyle, ISetStyleParent
     {
         private static Dictionary<IStyleable, List<IDisposable>> _applied =
             new Dictionary<IStyleable, List<IDisposable>>();

From 1bbc155303dbcdaffec3d8f36356e2467ba9fd99 Mon Sep 17 00:00:00 2001
From: Jeremy Koritzinsky <jkoritzinsky@gmail.com>
Date: Tue, 29 May 2018 15:35:08 -0500
Subject: [PATCH 04/24] Use a concrete type for the host type to avoid #959.

---
 src/Avalonia.Controls/Design.cs                    | 6 +++---
 src/Avalonia.DesignerSupport/DesignWindowLoader.cs | 3 +--
 src/Avalonia.Styling/Styling/IStyle.cs             | 2 +-
 3 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/src/Avalonia.Controls/Design.cs b/src/Avalonia.Controls/Design.cs
index 3a67e554ac..894240a09f 100644
--- a/src/Avalonia.Controls/Design.cs
+++ b/src/Avalonia.Controls/Design.cs
@@ -48,14 +48,14 @@ namespace Avalonia.Controls
         }
         
         public static readonly AttachedProperty<Control> PreviewWithProperty = AvaloniaProperty
-            .RegisterAttached<IStyle, Control>("PreviewWith", typeof (Design));
+            .RegisterAttached<Style, Control>("PreviewWith", typeof (Design));
 
-        public static void SetPreviewWith(IStyle target, Control control)
+        public static void SetPreviewWith(Style target, Control control)
         {
             target.SetValue(PreviewWithProperty, control);
         }
 
-        public static Control GetPreviewWith(IStyle target)
+        public static Control GetPreviewWith(Style target)
         {
             return target.GetValue(PreviewWithProperty);
         }
diff --git a/src/Avalonia.DesignerSupport/DesignWindowLoader.cs b/src/Avalonia.DesignerSupport/DesignWindowLoader.cs
index d1958ac9bf..6dca479d38 100644
--- a/src/Avalonia.DesignerSupport/DesignWindowLoader.cs
+++ b/src/Avalonia.DesignerSupport/DesignWindowLoader.cs
@@ -36,8 +36,7 @@ namespace Avalonia.DesignerSupport
                 var styles = loaded as Styles;
                 if (styles != null)
                 {
-                    var substitute = Design.GetPreviewWith(styles) ??
-                                     styles.Select(Design.GetPreviewWith).FirstOrDefault(s => s != null);
+                    var substitute = styles.OfType<Style>().Select(Design.GetPreviewWith).FirstOrDefault(s => s != null);
                     if (substitute != null)
                     {
                         substitute.Styles.AddRange(styles);
diff --git a/src/Avalonia.Styling/Styling/IStyle.cs b/src/Avalonia.Styling/Styling/IStyle.cs
index 2ce06cc36c..5f12763825 100644
--- a/src/Avalonia.Styling/Styling/IStyle.cs
+++ b/src/Avalonia.Styling/Styling/IStyle.cs
@@ -8,7 +8,7 @@ namespace Avalonia.Styling
     /// <summary>
     /// Defines the interface for styles.
     /// </summary>
-    public interface IStyle : IAvaloniaObject, IResourceNode
+    public interface IStyle : IResourceNode
     {
         /// <summary>
         /// Attaches the style to a control if the style's selector matches.

From ab36f86325bea0dcdc43b538daf2a5e648e3b8a9 Mon Sep 17 00:00:00 2001
From: CommonGuy <m-allenspach@hotmail.com>
Date: Wed, 30 May 2018 08:55:50 +0200
Subject: [PATCH 05/24] Add the NewLine property to TextBox

---
 src/Avalonia.Controls/TextBox.cs              | 16 +++++-
 .../TextBoxTests.cs                           | 53 +++++++++++++++++++
 2 files changed, 68 insertions(+), 1 deletion(-)

diff --git a/src/Avalonia.Controls/TextBox.cs b/src/Avalonia.Controls/TextBox.cs
index 874d2a3229..2ea9319194 100644
--- a/src/Avalonia.Controls/TextBox.cs
+++ b/src/Avalonia.Controls/TextBox.cs
@@ -68,6 +68,10 @@ namespace Avalonia.Controls
         public static readonly StyledProperty<bool> UseFloatingWatermarkProperty =
             AvaloniaProperty.Register<TextBox, bool>(nameof(UseFloatingWatermark));
 
+        public static readonly DirectProperty<TextBox, string> NewLineProperty =
+            AvaloniaProperty.RegisterDirect<TextBox, string>(nameof(NewLine),
+                textbox => textbox.NewLine, (textbox, newline) => textbox.NewLine = newline);
+
         struct UndoRedoState : IEquatable<UndoRedoState>
         {
             public string Text { get; }
@@ -90,6 +94,7 @@ namespace Avalonia.Controls
         private UndoRedoHelper<UndoRedoState> _undoRedoHelper;
         private bool _isUndoingRedoing;
         private bool _ignoreTextChanges;
+        private string _newLine = Environment.NewLine;
         private static readonly string[] invalidCharacters = new String[1] { "\u007f" };
 
         static TextBox()
@@ -241,6 +246,15 @@ namespace Avalonia.Controls
             set { SetValue(TextWrappingProperty, value); }
         }
 
+        /// <summary>
+        /// Gets or sets which characters are inserted when Enter is pressed. Default: <see cref="Environment.NewLine"/>
+        /// </summary>
+        public string NewLine
+        {
+            get { return _newLine; }
+            set { SetAndRaise(NewLineProperty, ref _newLine, value); }
+        }
+
         protected override void OnTemplateApplied(TemplateAppliedEventArgs e)
         {
             _presenter = e.NameScope.Get<TextPresenter>("PART_TextPresenter");
@@ -498,7 +512,7 @@ namespace Avalonia.Controls
                 case Key.Enter:
                     if (AcceptsReturn)
                     {
-                        HandleTextInput("\r\n");
+                        HandleTextInput(NewLine);
                         handled = true;
                     }
 
diff --git a/tests/Avalonia.Controls.UnitTests/TextBoxTests.cs b/tests/Avalonia.Controls.UnitTests/TextBoxTests.cs
index af461f07a4..4a8c171ecf 100644
--- a/tests/Avalonia.Controls.UnitTests/TextBoxTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/TextBoxTests.cs
@@ -247,6 +247,59 @@ namespace Avalonia.Controls.UnitTests
             }
         }
 
+        [Fact]
+        public void Press_Enter_Does_Not_Accept_Return()
+        {
+            using (UnitTestApplication.Start(Services))
+            {
+                var target = new TextBox
+                {
+                    Template = CreateTemplate(),
+                    AcceptsReturn = false,
+                    Text = "1234"
+                };
+
+                RaiseKeyEvent(target, Key.Enter, 0);
+
+                Assert.Equal("1234", target.Text);
+            }
+        }
+
+        [Fact]
+        public void Press_Enter_Add_Default_Newline()
+        {
+            using (UnitTestApplication.Start(Services))
+            {
+                var target = new TextBox
+                {
+                    Template = CreateTemplate(),
+                    AcceptsReturn = true
+                };
+
+                RaiseKeyEvent(target, Key.Enter, 0);
+
+                Assert.Equal(Environment.NewLine, target.Text);
+            }
+        }
+
+        [Fact]
+        public void Press_Enter_Add_Custom_Newline()
+        {
+            using (UnitTestApplication.Start(Services))
+            {
+                var target = new TextBox
+                {
+                    Template = CreateTemplate(),
+                    AcceptsReturn = true,
+                    NewLine = "Test"
+                };
+
+                RaiseKeyEvent(target, Key.Enter, 0);
+
+                Assert.Equal("Test", target.Text);
+            }
+        }
+
         [Theory]
         [InlineData(new object[] { false, TextWrapping.NoWrap, ScrollBarVisibility.Hidden })]
         [InlineData(new object[] { false, TextWrapping.Wrap, ScrollBarVisibility.Hidden })]

From 2f64e0f95275368debb431b05e4fbb07f48cc5cd Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Thu, 31 May 2018 19:46:23 +0200
Subject: [PATCH 06/24] Removed functionality implemented by #1190.

---
 src/Avalonia.Controls/Window.cs               |  7 +++---
 src/Avalonia.DesignerSupport/Remote/Stubs.cs  |  1 -
 .../Interop/UnmanagedMethods.cs               | 24 -------------------
 src/Windows/Avalonia.Win32/WindowImpl.cs      | 19 ---------------
 4 files changed, 3 insertions(+), 48 deletions(-)

diff --git a/src/Avalonia.Controls/Window.cs b/src/Avalonia.Controls/Window.cs
index 134fda2793..3cbfdbd657 100644
--- a/src/Avalonia.Controls/Window.cs
+++ b/src/Avalonia.Controls/Window.cs
@@ -148,9 +148,6 @@ namespace Avalonia.Controls
             impl.WindowStateChanged = HandleWindowStateChanged;
             _maxPlatformClientSize = PlatformImpl?.MaxClientSize ?? default(Size);
             Screens = new Screens(PlatformImpl?.Screen);
-
-            if (PlatformImpl != null)
-                PlatformImpl.WindowStateChanged = s => WindowState = s;
         }
         
         /// <inheritdoc/>
@@ -321,11 +318,13 @@ namespace Avalonia.Controls
 
         protected virtual void HandleWindowStateChanged(WindowState state)
         {
+            WindowState = state;
+
             if (state == WindowState.Minimized)
             {
                 Renderer.Stop();
             }
-            else if (state == WindowState.Normal)
+            else
             {
                 Renderer.Start();
             }
diff --git a/src/Avalonia.DesignerSupport/Remote/Stubs.cs b/src/Avalonia.DesignerSupport/Remote/Stubs.cs
index 72fce0d921..e749d10468 100644
--- a/src/Avalonia.DesignerSupport/Remote/Stubs.cs
+++ b/src/Avalonia.DesignerSupport/Remote/Stubs.cs
@@ -33,7 +33,6 @@ namespace Avalonia.DesignerSupport.Remote
         public Action<Point> PositionChanged { get; set; }
         public WindowState WindowState { get; set; }
         public Action<WindowState> WindowStateChanged { get; set; }
-
         public IRenderer CreateRenderer(IRenderRoot root) => new ImmediateRenderer(root);
         public void Dispose()
         {
diff --git a/src/Windows/Avalonia.Win32/Interop/UnmanagedMethods.cs b/src/Windows/Avalonia.Win32/Interop/UnmanagedMethods.cs
index a48d851e00..86dcec410b 100644
--- a/src/Windows/Avalonia.Win32/Interop/UnmanagedMethods.cs
+++ b/src/Windows/Avalonia.Win32/Interop/UnmanagedMethods.cs
@@ -104,30 +104,6 @@ namespace Avalonia.Win32.Interop
             ForceMinimize = 11
         }
 
-        public enum SysCommands
-        {
-            SC_SIZE = 0xF000,
-            SC_MOVE = 0xF010,
-            SC_MINIMIZE = 0xF020,
-            SC_MAXIMIZE = 0xF030,
-            SC_NEXTWINDOW = 0xF040,
-            SC_PREVWINDOW = 0xF050,
-            SC_CLOSE = 0xF060,
-            SC_VSCROLL = 0xF070,
-            SC_HSCROLL = 0xF080,
-            SC_MOUSEMENU = 0xF090,
-            SC_KEYMENU = 0xF100,
-            SC_ARRANGE = 0xF110,
-            SC_RESTORE = 0xF120,
-            SC_TASKLIST = 0xF130,
-            SC_SCREENSAVE = 0xF140,
-            SC_HOTKEY = 0xF150,
-            SC_DEFAULT = 0xF160,
-            SC_MONITORPOWER = 0xF170,
-            SC_CONTEXTHELP = 0xF180,
-            SC_SEPARATOR = 0xF00F,
-        }
-
         public enum SystemMetric
         {
             SM_CXSCREEN = 0,  // 0x00
diff --git a/src/Windows/Avalonia.Win32/WindowImpl.cs b/src/Windows/Avalonia.Win32/WindowImpl.cs
index 36e9cbb515..7b9f8ee066 100644
--- a/src/Windows/Avalonia.Win32/WindowImpl.cs
+++ b/src/Windows/Avalonia.Win32/WindowImpl.cs
@@ -650,25 +650,6 @@ namespace Avalonia.Win32
 
                     return IntPtr.Zero;
 
-                case UnmanagedMethods.WindowsMessage.WM_SYSCOMMAND:
-                    if (WindowStateChanged != null)
-                    {
-                        switch ((SysCommands)wParam)
-                        {
-                            case SysCommands.SC_MINIMIZE:
-                                WindowStateChanged(WindowState.Minimized);
-                                break;
-                            case SysCommands.SC_MAXIMIZE:
-                                WindowStateChanged(WindowState.Maximized);
-                                break;
-                            case SysCommands.SC_RESTORE:
-                                WindowStateChanged(WindowState.Normal);
-                                break;
-                        }
-                    }
-
-                    break;
-
                 case UnmanagedMethods.WindowsMessage.WM_MOVE:
                     PositionChanged?.Invoke(new Point((short)(ToInt32(lParam) & 0xffff), (short)(ToInt32(lParam) >> 16)));
                     return IntPtr.Zero;

From 29f3a72adf4de22277557b1c161f844b9aa5a4ab Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Thu, 31 May 2018 22:58:00 +0100
Subject: [PATCH 07/24] handle all CollectionChanged cases in carousel.

---
 .../Presenters/CarouselPresenter.cs           | 30 ++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/src/Avalonia.Controls/Presenters/CarouselPresenter.cs b/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
index c6ef5a14e9..64417a0176 100644
--- a/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
+++ b/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
@@ -106,7 +106,6 @@ namespace Avalonia.Controls.Presenters
         /// <inheritdoc/>
         protected override void ItemsChanged(NotifyCollectionChangedEventArgs e)
         {
-            // TODO: Handle items changing.           
             switch (e.Action)
             {
                 case NotifyCollectionChangedAction.Remove:
@@ -118,6 +117,35 @@ namespace Avalonia.Controls.Presenters
                     }
                     break;
 
+                case NotifyCollectionChangedAction.Reset:
+                    if(!IsVirtualized)
+                    {
+                        var generator = ItemContainerGenerator;
+                        var containers = generator.Containers.ToList();
+                        generator.Clear();
+                        Panel.Children.RemoveAll(containers.Select(x => x.ContainerControl));
+                    }
+                    break;
+
+                case NotifyCollectionChangedAction.Add:
+                    Panel.Children.InsertRange(e.NewStartingIndex, e.NewItems.OfType<IControl>());
+                    break;
+
+                case NotifyCollectionChangedAction.Replace:
+                    if (!IsVirtualized)
+                    {
+                        for (var i = 0; i < e.OldItems.Count; ++i)
+                        {
+                            var index = i + e.OldStartingIndex;
+                            var child = (IControl)e.NewItems[i];
+                            Panel.Children[index] = child;
+                        }
+                    }
+                    break;
+
+                case NotifyCollectionChangedAction.Move:
+                    Panel.Children.MoveRange(e.OldStartingIndex, e.OldItems.Count, e.NewStartingIndex);
+                    break;                   
             }
         }
 

From efb8fde1bb357b6213429c5cf95cddb91843fa03 Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Thu, 31 May 2018 23:15:58 +0100
Subject: [PATCH 08/24] remove handling add case.

---
 src/Avalonia.Controls/Presenters/CarouselPresenter.cs | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/src/Avalonia.Controls/Presenters/CarouselPresenter.cs b/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
index 64417a0176..f62f146b2a 100644
--- a/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
+++ b/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
@@ -127,10 +127,6 @@ namespace Avalonia.Controls.Presenters
                     }
                     break;
 
-                case NotifyCollectionChangedAction.Add:
-                    Panel.Children.InsertRange(e.NewStartingIndex, e.NewItems.OfType<IControl>());
-                    break;
-
                 case NotifyCollectionChangedAction.Replace:
                     if (!IsVirtualized)
                     {

From 9c3bf3231a6b36158929aaff55cbe7e0e8f6ab53 Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Thu, 31 May 2018 23:35:42 +0100
Subject: [PATCH 09/24] fix unit tests.

---
 src/Avalonia.Controls/Presenters/ItemsPresenterBase.cs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/Avalonia.Controls/Presenters/ItemsPresenterBase.cs b/src/Avalonia.Controls/Presenters/ItemsPresenterBase.cs
index 5a56e52029..e8abb7e901 100644
--- a/src/Avalonia.Controls/Presenters/ItemsPresenterBase.cs
+++ b/src/Avalonia.Controls/Presenters/ItemsPresenterBase.cs
@@ -240,9 +240,9 @@ namespace Avalonia.Controls.Presenters
                 incc.CollectionChanged += ItemsCollectionChanged;
             }
 
-            PanelCreated(Panel);
-
             ItemsChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
+
+            PanelCreated(Panel);            
         }
 
         /// <summary>

From bd3bbb03817c43fc2e257cd158f73f574ac09458 Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Thu, 31 May 2018 23:46:46 +0100
Subject: [PATCH 10/24] fix tests again.

---
 src/Avalonia.Controls/Presenters/ItemsPresenterBase.cs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/Avalonia.Controls/Presenters/ItemsPresenterBase.cs b/src/Avalonia.Controls/Presenters/ItemsPresenterBase.cs
index e8abb7e901..c3412d2cd1 100644
--- a/src/Avalonia.Controls/Presenters/ItemsPresenterBase.cs
+++ b/src/Avalonia.Controls/Presenters/ItemsPresenterBase.cs
@@ -240,9 +240,9 @@ namespace Avalonia.Controls.Presenters
                 incc.CollectionChanged += ItemsCollectionChanged;
             }
 
-            ItemsChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
+            PanelCreated(Panel);
 
-            PanelCreated(Panel);            
+            ItemsChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));            
         }
 
         /// <summary>

From d2735eea8d822ea55dd131ded05dc079ed450563 Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Fri, 1 Jun 2018 00:07:36 +0100
Subject: [PATCH 11/24] regenerate containers.

---
 src/Avalonia.Controls/Presenters/CarouselPresenter.cs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/Avalonia.Controls/Presenters/CarouselPresenter.cs b/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
index f62f146b2a..3ae9a77587 100644
--- a/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
+++ b/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
@@ -124,6 +124,8 @@ namespace Avalonia.Controls.Presenters
                         var containers = generator.Containers.ToList();
                         generator.Clear();
                         Panel.Children.RemoveAll(containers.Select(x => x.ContainerControl));
+
+                        PanelCreated(Panel);
                     }
                     break;
 

From 65d57262b2eaa90022c4b42fe71429d1e59631db Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Fri, 1 Jun 2018 11:45:59 +0100
Subject: [PATCH 12/24] Add unit tests to demonstrate the issues with Carousel

---
 .../CarouselTests.cs                          | 74 +++++++++++++++++++
 1 file changed, 74 insertions(+)

diff --git a/tests/Avalonia.Controls.UnitTests/CarouselTests.cs b/tests/Avalonia.Controls.UnitTests/CarouselTests.cs
index 4d38ec9856..79d573bd1b 100644
--- a/tests/Avalonia.Controls.UnitTests/CarouselTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/CarouselTests.cs
@@ -1,6 +1,7 @@
 // Copyright (c) The Avalonia Project. All rights reserved.
 // Licensed under the MIT license. See licence.md file in the project root for full license information.
 
+using System.Collections.ObjectModel;
 using System.Linq;
 using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Primitives;
@@ -93,6 +94,79 @@ namespace Avalonia.Controls.UnitTests
             Assert.Equal(2, target.ItemContainerGenerator.Containers.Count());
         }
 
+        [Fact]
+        public void Selected_Item_Changes_To_First_Item_When_Items_Property_Changes()
+        {
+            var items = new ObservableCollection<string>
+            {
+               "Foo",
+               "Bar",
+               "FooBar"
+            };
+
+            var target = new Carousel
+            {
+                Template = new FuncControlTemplate<Carousel>(CreateTemplate),
+                Items =  items,
+                IsVirtualized = false
+            };
+
+            target.ApplyTemplate();
+            target.Presenter.ApplyTemplate();
+
+            Assert.Single(target.GetLogicalChildren());
+
+            var child = target.GetLogicalChildren().Single();
+
+            Assert.IsType<TextBlock>(child);
+            Assert.Equal("Foo", ((TextBlock)child).Text);
+
+            var newItems = items.ToList();
+            newItems.RemoveAt(0);
+
+            target.Items = newItems;
+
+            child = target.GetLogicalChildren().Single();
+
+            Assert.IsType<TextBlock>(child);
+            Assert.Equal("Bar", ((TextBlock)child).Text);
+        }
+
+        [Fact]
+        public void Selected_Item_Changes_To_Next_First_Item_When_Item_Removed_From_Beggining_Of_List()
+        {
+            var items = new ObservableCollection<string>
+            {
+               "Foo",
+               "Bar",
+               "FooBar"
+            };
+
+            var target = new Carousel
+            {
+                Template = new FuncControlTemplate<Carousel>(CreateTemplate),
+                Items = items,
+                IsVirtualized = false
+            };
+
+            target.ApplyTemplate();
+            target.Presenter.ApplyTemplate();
+
+            Assert.Single(target.GetLogicalChildren());
+
+            var child = target.GetLogicalChildren().Single();
+
+            Assert.IsType<TextBlock>(child);
+            Assert.Equal("Foo", ((TextBlock)child).Text);
+
+            items.RemoveAt(0);
+
+            child = target.GetLogicalChildren().Single();
+
+            Assert.IsType<TextBlock>(child);
+            Assert.Equal("Bar", ((TextBlock)child).Text);
+        }
+
         private Control CreateTemplate(Carousel control)
         {
             return new CarouselPresenter

From 055f7b216ec8e0430b493bc2d1ad72f0b2dd2ed8 Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Fri, 1 Jun 2018 11:46:17 +0100
Subject: [PATCH 13/24] Add correct fixes for Carousel issue.

---
 .../Presenters/CarouselPresenter.cs           | 22 ++++---------------
 1 file changed, 4 insertions(+), 18 deletions(-)

diff --git a/src/Avalonia.Controls/Presenters/CarouselPresenter.cs b/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
index 3ae9a77587..72a3e7404a 100644
--- a/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
+++ b/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
@@ -114,6 +114,8 @@ namespace Avalonia.Controls.Presenters
                         var generator = ItemContainerGenerator;
                         var containers = generator.RemoveRange(e.OldStartingIndex, e.OldItems.Count);
                         Panel.Children.RemoveAll(containers.Select(x => x.ContainerControl));
+
+                        MoveToPage(-1, 0);
                     }
                     break;
 
@@ -125,25 +127,9 @@ namespace Avalonia.Controls.Presenters
                         generator.Clear();
                         Panel.Children.RemoveAll(containers.Select(x => x.ContainerControl));
 
-                        PanelCreated(Panel);
-                    }
-                    break;
-
-                case NotifyCollectionChangedAction.Replace:
-                    if (!IsVirtualized)
-                    {
-                        for (var i = 0; i < e.OldItems.Count; ++i)
-                        {
-                            var index = i + e.OldStartingIndex;
-                            var child = (IControl)e.NewItems[i];
-                            Panel.Children[index] = child;
-                        }
+                        MoveToPage(-1, 0);
                     }
-                    break;
-
-                case NotifyCollectionChangedAction.Move:
-                    Panel.Children.MoveRange(e.OldStartingIndex, e.OldItems.Count, e.NewStartingIndex);
-                    break;                   
+                    break;     
             }
         }
 

From 511e308bf37f2f38803ea1df9c89645b48cf50e7 Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Fri, 1 Jun 2018 11:47:34 +0100
Subject: [PATCH 14/24] fix whitespace.

---
 src/Avalonia.Controls/Presenters/ItemsPresenterBase.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Avalonia.Controls/Presenters/ItemsPresenterBase.cs b/src/Avalonia.Controls/Presenters/ItemsPresenterBase.cs
index c3412d2cd1..5a56e52029 100644
--- a/src/Avalonia.Controls/Presenters/ItemsPresenterBase.cs
+++ b/src/Avalonia.Controls/Presenters/ItemsPresenterBase.cs
@@ -242,7 +242,7 @@ namespace Avalonia.Controls.Presenters
 
             PanelCreated(Panel);
 
-            ItemsChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));            
+            ItemsChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
         }
 
         /// <summary>

From 2900333f698f1e68f192506e3f50be16af4d1b0a Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Fri, 1 Jun 2018 12:05:15 +0100
Subject: [PATCH 15/24] Add test to ensure SelectedIndex / SelectedItem is
 maintained when

items are removed mid-list.
---
 .../Presenters/CarouselPresenter.cs           |  2 +-
 .../CarouselTests.cs                          | 28 +++++++++++++++++++
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/src/Avalonia.Controls/Presenters/CarouselPresenter.cs b/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
index 72a3e7404a..04aa4a1640 100644
--- a/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
+++ b/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
@@ -115,7 +115,7 @@ namespace Avalonia.Controls.Presenters
                         var containers = generator.RemoveRange(e.OldStartingIndex, e.OldItems.Count);
                         Panel.Children.RemoveAll(containers.Select(x => x.ContainerControl));
 
-                        MoveToPage(-1, 0);
+                        MoveToPage(-1, SelectedIndex);
                     }
                     break;
 
diff --git a/tests/Avalonia.Controls.UnitTests/CarouselTests.cs b/tests/Avalonia.Controls.UnitTests/CarouselTests.cs
index 79d573bd1b..c80e1edb43 100644
--- a/tests/Avalonia.Controls.UnitTests/CarouselTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/CarouselTests.cs
@@ -167,6 +167,34 @@ namespace Avalonia.Controls.UnitTests
             Assert.Equal("Bar", ((TextBlock)child).Text);
         }
 
+        [Fact]
+        public void Selected_Item_Changes_To_NextAvailable_Item_If_SelectedItem_Is_Removed_From_Middle()
+        {
+            var items = new ObservableCollection<string>
+            {
+               "Foo",
+               "Bar",
+               "FooBar"
+            };
+
+            var target = new Carousel
+            {
+                Template = new FuncControlTemplate<Carousel>(CreateTemplate),
+                Items = items,
+                IsVirtualized = false
+            };
+
+            target.ApplyTemplate();
+            target.Presenter.ApplyTemplate();
+
+            target.SelectedIndex = 1;
+
+            items.RemoveAt(1);
+
+            Assert.Equal(1, target.SelectedIndex);
+            Assert.Equal("FooBar", target.SelectedItem);
+        }
+
         private Control CreateTemplate(Carousel control)
         {
             return new CarouselPresenter

From 2a78b5e9c25ecd13d49fe1e2e12cd09ceebaf3a4 Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Fri, 1 Jun 2018 13:03:16 +0100
Subject: [PATCH 16/24] Add unit test and Fix for case where TemplateApplied
 when SelectedIndex is already set.

---
 .../Presenters/CarouselPresenter.cs           |  2 +-
 .../CarouselTests.cs                          | 49 ++++++++++++++++++-
 2 files changed, 48 insertions(+), 3 deletions(-)

diff --git a/src/Avalonia.Controls/Presenters/CarouselPresenter.cs b/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
index 04aa4a1640..28182fd8aa 100644
--- a/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
+++ b/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
@@ -127,7 +127,7 @@ namespace Avalonia.Controls.Presenters
                         generator.Clear();
                         Panel.Children.RemoveAll(containers.Select(x => x.ContainerControl));
 
-                        MoveToPage(-1, 0);
+                        MoveToPage(-1, SelectedIndex >= 0 ? SelectedIndex : 0);
                     }
                     break;     
             }
diff --git a/tests/Avalonia.Controls.UnitTests/CarouselTests.cs b/tests/Avalonia.Controls.UnitTests/CarouselTests.cs
index c80e1edb43..c5f1d64e6a 100644
--- a/tests/Avalonia.Controls.UnitTests/CarouselTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/CarouselTests.cs
@@ -7,6 +7,7 @@ using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Primitives;
 using Avalonia.Controls.Templates;
 using Avalonia.LogicalTree;
+using Avalonia.VisualTree;
 using Xunit;
 
 namespace Avalonia.Controls.UnitTests
@@ -51,7 +52,7 @@ namespace Avalonia.Controls.UnitTests
             Assert.Single(target.GetLogicalChildren());
 
             var child = target.GetLogicalChildren().Single();
-            
+
             Assert.IsType<TextBlock>(child);
             Assert.Equal("Foo", ((TextBlock)child).Text);
         }
@@ -107,7 +108,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new Carousel
             {
                 Template = new FuncControlTemplate<Carousel>(CreateTemplate),
-                Items =  items,
+                Items = items,
                 IsVirtualized = false
             };
 
@@ -132,6 +133,50 @@ namespace Avalonia.Controls.UnitTests
             Assert.Equal("Bar", ((TextBlock)child).Text);
         }
 
+        [Fact]
+        public void Selected_Index_Is_Maintained_Carousel_Created_With_Non_Zero_SelectedIndex()
+        {
+            var items = new ObservableCollection<string>
+            {
+               "Foo",
+               "Bar",
+               "FooBar"
+            };
+
+            var target = new Carousel
+            {
+                Template = new FuncControlTemplate<Carousel>(CreateTemplate),
+                Items = items,
+                IsVirtualized = false,
+                SelectedIndex = 2
+            };
+
+            target.ApplyTemplate();
+            target.Presenter.ApplyTemplate();
+
+            Assert.Equal("FooBar", target.SelectedItem);
+
+            IVisual child = target;
+
+            while (true)
+            {
+                if (child.VisualChildren.FirstOrDefault() is TextBlock)
+                {
+                    break;
+                }
+
+                if (child.VisualChildren.Count == 0)
+                {
+                    break;
+
+                }
+                child = child.VisualChildren.FirstOrDefault().VisualChildren.FirstOrDefault();
+            }
+
+            Assert.IsType<TextBlock>(child);
+            Assert.Equal("FooBar", ((TextBlock)child).Text);
+        }
+
         [Fact]
         public void Selected_Item_Changes_To_Next_First_Item_When_Item_Removed_From_Beggining_Of_List()
         {

From 612d99d01eec73426d8dbd3d948e303ad0a515c9 Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Fri, 1 Jun 2018 15:54:46 +0100
Subject: [PATCH 17/24] use GetVisualDescendents in test.

---
 .../CarouselTests.cs                            | 17 +----------------
 1 file changed, 1 insertion(+), 16 deletions(-)

diff --git a/tests/Avalonia.Controls.UnitTests/CarouselTests.cs b/tests/Avalonia.Controls.UnitTests/CarouselTests.cs
index c5f1d64e6a..932a1bea68 100644
--- a/tests/Avalonia.Controls.UnitTests/CarouselTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/CarouselTests.cs
@@ -156,22 +156,7 @@ namespace Avalonia.Controls.UnitTests
 
             Assert.Equal("FooBar", target.SelectedItem);
 
-            IVisual child = target;
-
-            while (true)
-            {
-                if (child.VisualChildren.FirstOrDefault() is TextBlock)
-                {
-                    break;
-                }
-
-                if (child.VisualChildren.Count == 0)
-                {
-                    break;
-
-                }
-                child = child.VisualChildren.FirstOrDefault().VisualChildren.FirstOrDefault();
-            }
+            var child = target.GetVisualDescendants().LastOrDefault();
 
             Assert.IsType<TextBlock>(child);
             Assert.Equal("FooBar", ((TextBlock)child).Text);

From 3536496f2113faaac4dbafe3f33a8097e05f8e5b Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Fri, 1 Jun 2018 15:58:50 +0100
Subject: [PATCH 18/24] Add test for when carousel Items is reset and
 virtualized.

---
 .../Presenters/CarouselPresenter.cs           |  1 -
 .../CarouselTests.cs                          | 37 +++++++++++++++++++
 2 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/src/Avalonia.Controls/Presenters/CarouselPresenter.cs b/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
index 28182fd8aa..144174e371 100644
--- a/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
+++ b/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
@@ -120,7 +120,6 @@ namespace Avalonia.Controls.Presenters
                     break;
 
                 case NotifyCollectionChangedAction.Reset:
-                    if(!IsVirtualized)
                     {
                         var generator = ItemContainerGenerator;
                         var containers = generator.Containers.ToList();
diff --git a/tests/Avalonia.Controls.UnitTests/CarouselTests.cs b/tests/Avalonia.Controls.UnitTests/CarouselTests.cs
index 932a1bea68..df61698209 100644
--- a/tests/Avalonia.Controls.UnitTests/CarouselTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/CarouselTests.cs
@@ -133,6 +133,43 @@ namespace Avalonia.Controls.UnitTests
             Assert.Equal("Bar", ((TextBlock)child).Text);
         }
 
+        [Fact]
+        public void Selected_Item_Changes_To_First_Item_When_Items_Property_Changes_And_Virtualized()
+        {
+            var items = new ObservableCollection<string>
+            {
+               "Foo",
+               "Bar",
+               "FooBar"
+            };
+
+            var target = new Carousel
+            {
+                Template = new FuncControlTemplate<Carousel>(CreateTemplate),
+                Items = items
+            };
+
+            target.ApplyTemplate();
+            target.Presenter.ApplyTemplate();
+
+            Assert.Single(target.GetLogicalChildren());
+
+            var child = target.GetLogicalChildren().Single();
+
+            Assert.IsType<TextBlock>(child);
+            Assert.Equal("Foo", ((TextBlock)child).Text);
+
+            var newItems = items.ToList();
+            newItems.RemoveAt(0);
+
+            target.Items = newItems;
+
+            child = target.GetLogicalChildren().Single();
+
+            Assert.IsType<TextBlock>(child);
+            Assert.Equal("Bar", ((TextBlock)child).Text);
+        }
+
         [Fact]
         public void Selected_Index_Is_Maintained_Carousel_Created_With_Non_Zero_SelectedIndex()
         {

From 15bb5cf88fae4b9a36655ee7decda5e69370bb91 Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Mon, 4 Jun 2018 19:02:01 +0100
Subject: [PATCH 19/24] fix bug introduced in dropdownitem the clears :selected
 psuedo class

from any control that has IsFocusedProperty.
---
 src/Avalonia.Controls/DropDownItem.cs | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/src/Avalonia.Controls/DropDownItem.cs b/src/Avalonia.Controls/DropDownItem.cs
index 3fd80c4562..fb465e93ec 100644
--- a/src/Avalonia.Controls/DropDownItem.cs
+++ b/src/Avalonia.Controls/DropDownItem.cs
@@ -22,14 +22,13 @@ namespace Avalonia.Controls
         static DropDownItem()
         {
             FocusableProperty.OverrideDefaultValue<DropDownItem>(true);
-            IsFocusedProperty.Changed.Subscribe(x =>
-            {
-                var sender = x.Sender as IControl;
+        }
 
-                if (sender != null)
-                {
-                    ((IPseudoClasses)sender.Classes).Set(":selected", (bool)x.NewValue);
-                }
+        public DropDownItem()
+        {
+            this.GetObservable(DropDownItem.IsFocusedProperty).Subscribe(focused =>
+            {
+                PseudoClasses.Set(":selected", focused);                
             });
         }
 

From e8810e3ac323132ef7604c3397ac753b75235b6e Mon Sep 17 00:00:00 2001
From: Benedikt Schroeder <benedikt.schroeder@outlook.de>
Date: Tue, 5 Jun 2018 14:13:44 +0200
Subject: [PATCH 20/24] Implicit string to font family conversion now uses
 Parse to convert

---
 src/Avalonia.Visuals/Media/FontFamily.cs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/Avalonia.Visuals/Media/FontFamily.cs b/src/Avalonia.Visuals/Media/FontFamily.cs
index a4b4f5085a..70a4aee4cd 100644
--- a/src/Avalonia.Visuals/Media/FontFamily.cs
+++ b/src/Avalonia.Visuals/Media/FontFamily.cs
@@ -77,10 +77,10 @@ namespace Avalonia.Media
         /// <summary>
         /// Implicit conversion of string to FontFamily
         /// </summary>
-        /// <param name="fontFamily"></param>
-        public static implicit operator FontFamily(string fontFamily)
+        /// <param name="s"></param>
+        public static implicit operator FontFamily(string s)
         {
-            return new FontFamily(fontFamily);
+            return Parse(s);
         }
 
         /// <summary>

From 1f0e173e95871e8c3941f93f96c4670311dbc89c Mon Sep 17 00:00:00 2001
From: Jeremy Koritzinsky <jkortizinsky@gmail.com>
Date: Tue, 5 Jun 2018 16:11:08 -0500
Subject: [PATCH 21/24] Fix the inspection errors. Also clean up some Calendar
 code in the meantime since most of the warnings were there.

---
 .../ControlCatalog/DecoratedWindow.xaml.cs    |  4 +-
 src/Avalonia.Controls/AutoCompleteBox.cs      |  2 +-
 src/Avalonia.Controls/Calendar/Calendar.cs    | 95 ++++++++-----------
 .../Calendar/CalendarDateRange.cs             |  2 +-
 .../Calendar/CalendarItem.cs                  | 31 +++---
 src/Avalonia.Controls/Calendar/DatePicker.cs  |  2 +-
 .../Embedding/Offscreen/OffscreenTopLevel.cs  |  2 +-
 .../Platform/InProcessDragSource.cs           |  2 +-
 src/Avalonia.Themes.Default/Calendar.xaml     |  5 +-
 .../Avalonia.Markup/Data/MultiBinding.cs      |  3 +-
 .../Avalonia.Win32/SystemDialogImpl.cs        |  2 +-
 11 files changed, 67 insertions(+), 83 deletions(-)

diff --git a/samples/ControlCatalog/DecoratedWindow.xaml.cs b/samples/ControlCatalog/DecoratedWindow.xaml.cs
index d28281e476..749f83c1ab 100644
--- a/samples/ControlCatalog/DecoratedWindow.xaml.cs
+++ b/samples/ControlCatalog/DecoratedWindow.xaml.cs
@@ -20,7 +20,7 @@ namespace ControlCatalog
             ctl.Cursor = new Cursor(cursor);
             ctl.PointerPressed += delegate
             {
-                PlatformImpl.BeginResizeDrag(edge);
+                PlatformImpl?.BeginResizeDrag(edge);
             };
         }
 
@@ -29,7 +29,7 @@ namespace ControlCatalog
             AvaloniaXamlLoader.Load(this);
             this.FindControl<Control>("TitleBar").PointerPressed += delegate
             {
-                PlatformImpl.BeginMoveDrag();
+                PlatformImpl?.BeginMoveDrag();
             };
             SetupSide("Left", StandardCursorType.LeftSide, WindowEdge.West);
             SetupSide("Right", StandardCursorType.RightSide, WindowEdge.East);
diff --git a/src/Avalonia.Controls/AutoCompleteBox.cs b/src/Avalonia.Controls/AutoCompleteBox.cs
index 351cbf5520..96fb9be8ac 100644
--- a/src/Avalonia.Controls/AutoCompleteBox.cs
+++ b/src/Avalonia.Controls/AutoCompleteBox.cs
@@ -2150,7 +2150,7 @@ namespace Avalonia.Controls
             }
 
             // Update the view
-            if (e.Action == NotifyCollectionChangedAction.Remove || e.Action == NotifyCollectionChangedAction.Replace)
+            if ((e.Action == NotifyCollectionChangedAction.Remove || e.Action == NotifyCollectionChangedAction.Replace) && e.OldItems != null)
             {
                 for (int index = 0; index < e.OldItems.Count; index++)
                 {
diff --git a/src/Avalonia.Controls/Calendar/Calendar.cs b/src/Avalonia.Controls/Calendar/Calendar.cs
index 59281c5ad0..029e4dadc8 100644
--- a/src/Avalonia.Controls/Calendar/Calendar.cs
+++ b/src/Avalonia.Controls/Calendar/Calendar.cs
@@ -769,7 +769,7 @@ namespace Avalonia.Controls
         }
         private static void UpdateDisplayDate(Calendar c, DateTime addedDate, DateTime removedDate)
         {
-            Debug.Assert(c != null, "c should not be null!");
+            Contract.Requires<ArgumentNullException>(c != null);
 
             // If DisplayDate < DisplayDateStart, DisplayDate = DisplayDateStart
             if (DateTime.Compare(addedDate, c.DisplayDateRangeStart) < 0)
@@ -1016,8 +1016,6 @@ namespace Avalonia.Controls
 
         internal CalendarDayButton FindDayButtonFromDay(DateTime day)
         {
-            CalendarDayButton b;
-            DateTime? d;
             CalendarItem monthControl = MonthControl;
 
             // REMOVE_RTM: should be updated if we support MultiCalendar
@@ -1028,14 +1026,16 @@ namespace Avalonia.Controls
                 {
                     for (int childIndex = ColumnsPerMonth; childIndex < count; childIndex++)
                     {
-                        b = monthControl.MonthView.Children[childIndex] as CalendarDayButton;
-                        d = b.DataContext as DateTime?;
-
-                        if (d.HasValue)
+                        if (monthControl.MonthView.Children[childIndex] is CalendarDayButton b)
                         {
-                            if (DateTimeHelper.CompareDays(d.Value, day) == 0)
+                            var d = b.DataContext as DateTime?;
+
+                            if (d.HasValue)
                             {
-                                return b;
+                                if (DateTimeHelper.CompareDays(d.Value, day) == 0)
+                                {
+                                    return b;
+                                }
                             }
                         }
                     }
@@ -1044,20 +1044,6 @@ namespace Avalonia.Controls
             return null;
         }
 
-        private void Calendar_SizeChanged(object sender, EventArgs e)
-        {
-            Debug.Assert(sender is Calendar, "The sender should be a Calendar!");
-
-            var size = Bounds.Size;
-            RectangleGeometry rg = new RectangleGeometry();
-            rg.Rect = new Rect(0, 0, size.Width, size.Height);
-
-            if (Root != null)
-            {
-                Root.Clip = rg;
-            }
-        }
-
         private void OnSelectedMonthChanged(DateTime? selectedMonth)
         {
             if (selectedMonth.HasValue)
@@ -1090,7 +1076,6 @@ namespace Avalonia.Controls
 
         internal void ResetStates()
         {
-            CalendarDayButton d;
             CalendarItem monthControl = MonthControl;
             int count = RowsPerMonth * ColumnsPerMonth;
             if (monthControl != null)
@@ -1099,7 +1084,7 @@ namespace Avalonia.Controls
                 {
                     for (int childIndex = ColumnsPerMonth; childIndex < count; childIndex++)
                     {
-                        d = monthControl.MonthView.Children[childIndex] as CalendarDayButton;
+                        var d = (CalendarDayButton)monthControl.MonthView.Children[childIndex];
                         d.IgnoreMouseOverState();
                     }
                 }
@@ -1190,8 +1175,6 @@ namespace Avalonia.Controls
             if (HoverEnd != null && HoverStart != null)
             {
                 int startIndex, endIndex, i;
-                CalendarDayButton b;
-                DateTime? d;
                 CalendarItem monthControl = MonthControl;
 
                 // This assumes a contiguous set of dates:
@@ -1201,18 +1184,20 @@ namespace Avalonia.Controls
 
                     for (i = startIndex; i <= endIndex; i++)
                     {
-                        b = monthControl.MonthView.Children[i] as CalendarDayButton;
-                        b.IsSelected = true;
-                        d = b.DataContext as DateTime?;
-
-                        if (d.HasValue && DateTimeHelper.CompareDays(HoverEnd.Value, d.Value) == 0)
+                        if (monthControl.MonthView.Children[i] is CalendarDayButton b)
                         {
-                            if (FocusButton != null)
+                            b.IsSelected = true;
+                            var d = b.DataContext as DateTime?;
+
+                            if (d.HasValue && DateTimeHelper.CompareDays(HoverEnd.Value, d.Value) == 0)
                             {
-                                FocusButton.IsCurrent = false;
+                                if (FocusButton != null)
+                                {
+                                    FocusButton.IsCurrent = false;
+                                }
+                                b.IsCurrent = HasFocusInternal;
+                                FocusButton = b;
                             }
-                            b.IsCurrent = HasFocusInternal;
-                            FocusButton = b;
                         }
                     }
                 }
@@ -1228,8 +1213,6 @@ namespace Avalonia.Controls
             if (HoverEnd != null && HoverStart != null)
             {
                 CalendarItem monthControl = MonthControl;
-                CalendarDayButton b;
-                DateTime? d;
 
                 if (HoverEndIndex != null && HoverStartIndex != null)
                 {
@@ -1240,15 +1223,17 @@ namespace Avalonia.Controls
                     {
                         for (i = startIndex; i <= endIndex; i++)
                         {
-                            b = monthControl.MonthView.Children[i] as CalendarDayButton;
-                            d = b.DataContext as DateTime?;
-
-                            if (d.HasValue)
+                            if (monthControl.MonthView.Children[i] is CalendarDayButton b)
                             {
-                                if (!SelectedDates.Contains(d.Value))
+                                var d = b.DataContext as DateTime?;
+
+                                if (d.HasValue)
                                 {
-                                    b.IsSelected = false;
-                                }
+                                    if (!SelectedDates.Contains(d.Value))
+                                    {
+                                        b.IsSelected = false;
+                                    }
+                                } 
                             }
                         }
                     }
@@ -1257,7 +1242,7 @@ namespace Avalonia.Controls
                         // It is SingleRange
                         for (i = startIndex; i <= endIndex; i++)
                         {
-                            (monthControl.MonthView.Children[i] as CalendarDayButton).IsSelected = false;
+                            ((CalendarDayButton)monthControl.MonthView.Children[i]).IsSelected = false;
                         }
                     }
                 }
@@ -1628,16 +1613,15 @@ namespace Avalonia.Controls
                 e.Handled = true;
             }
         }
-        internal void Calendar_KeyDown(object sender, KeyEventArgs e)
-        {
-            Calendar c = sender as Calendar;
-            Debug.Assert(c != null, "c should not be null!");
 
-            if (!e.Handled && c.IsEnabled)
+        internal void Calendar_KeyDown(KeyEventArgs e)
+        {
+            if (!e.Handled && IsEnabled)
             {
                 e.Handled = ProcessCalendarKey(e);
             }
         }
+
         internal bool ProcessCalendarKey(KeyEventArgs e)
         {
             if (DisplayMode == CalendarMode.Month)
@@ -1976,7 +1960,7 @@ namespace Avalonia.Controls
                     }
             }
         }
-        private void Calendar_KeyUp(object sender, KeyEventArgs e)
+        private void Calendar_KeyUp(KeyEventArgs e)
         {
             if (!e.Handled && (e.Key == Key.LeftShift || e.Key == Key.RightShift))
             {
@@ -2083,6 +2067,9 @@ namespace Avalonia.Controls
             DisplayDateProperty.Changed.AddClassHandler<Calendar>(x => x.OnDisplayDateChanged);
             DisplayDateStartProperty.Changed.AddClassHandler<Calendar>(x => x.OnDisplayDateStartChanged);
             DisplayDateEndProperty.Changed.AddClassHandler<Calendar>(x => x.OnDisplayDateEndChanged);
+            KeyDownEvent.AddClassHandler<Calendar>(x => x.Calendar_KeyDown);
+            KeyUpEvent.AddClassHandler<Calendar>(x => x.Calendar_KeyUp);
+            
         }
 
         /// <summary>
@@ -2122,10 +2109,6 @@ namespace Avalonia.Controls
                     month.Owner = this;
                 }
             }
-
-            LayoutUpdated += Calendar_SizeChanged;
-            KeyDown += Calendar_KeyDown;
-            KeyUp += Calendar_KeyUp;
         }
 
     }
diff --git a/src/Avalonia.Controls/Calendar/CalendarDateRange.cs b/src/Avalonia.Controls/Calendar/CalendarDateRange.cs
index 273cda8c5b..718cc7142b 100644
--- a/src/Avalonia.Controls/Calendar/CalendarDateRange.cs
+++ b/src/Avalonia.Controls/Calendar/CalendarDateRange.cs
@@ -66,7 +66,7 @@ namespace Avalonia.Controls
         /// <returns>Inherited code: Requires comment 2.</returns>
         internal bool ContainsAny(CalendarDateRange range)
         {
-            Debug.Assert(range != null, "range should not be null!");
+            Contract.Requires<ArgumentNullException>(range != null);
 
             int start = DateTime.Compare(Start, range.Start);
 
diff --git a/src/Avalonia.Controls/Calendar/CalendarItem.cs b/src/Avalonia.Controls/Calendar/CalendarItem.cs
index 3432fa549d..b0cbd0be53 100644
--- a/src/Avalonia.Controls/Calendar/CalendarItem.cs
+++ b/src/Avalonia.Controls/Calendar/CalendarItem.cs
@@ -517,7 +517,7 @@ namespace Avalonia.Controls.Primitives
             for (int childIndex = Calendar.ColumnsPerMonth; childIndex < count; childIndex++)
             {
                 CalendarDayButton childButton = MonthView.Children[childIndex] as CalendarDayButton;
-                Debug.Assert(childButton != null, "childButton should not be null!");
+                Contract.Requires<ArgumentNullException>(childButton != null);
 
                 childButton.Index = childIndex;
                 SetButtonState(childButton, dateToAdd);
@@ -554,7 +554,7 @@ namespace Avalonia.Controls.Primitives
                     for (int i = childIndex; i < count; i++)
                     {
                         childButton = MonthView.Children[i] as CalendarDayButton;
-                        Debug.Assert(childButton != null, "childButton should not be null!");
+                        Contract.Requires<ArgumentNullException>(childButton != null);
                         // button needs a content to occupy the necessary space
                         // for the content presenter
                         childButton.Content = i.ToString(DateTimeHelper.GetCurrentDateFormat());
@@ -650,7 +650,7 @@ namespace Avalonia.Controls.Primitives
             foreach (object child in YearView.Children)
             {
                 CalendarButton childButton = child as CalendarButton;
-                Debug.Assert(childButton != null, "childButton should not be null!");
+                Contract.Requires<ArgumentNullException>(childButton != null);
                 // There should be no time component. Time is 12:00 AM
                 DateTime day = new DateTime(_currentMonth.Year, count + 1, 1);
                 childButton.DataContext = day;
@@ -746,7 +746,7 @@ namespace Avalonia.Controls.Primitives
             foreach (object child in YearView.Children)
             {
                 CalendarButton childButton = child as CalendarButton;
-                Debug.Assert(childButton != null, "childButton should not be null!");
+                Contract.Requires<ArgumentNullException>(childButton != null);
                 year = decade + count;
 
                 if (year <= DateTime.MaxValue.Year && year >= DateTime.MinValue.Year)
@@ -826,7 +826,7 @@ namespace Avalonia.Controls.Primitives
                 {
                     Owner.Focus();
                 }
-                Button b = sender as Button;
+                Button b = (Button)sender;
                 DateTime d;
 
                 if (b.IsEnabled)
@@ -863,7 +863,7 @@ namespace Avalonia.Controls.Primitives
                     Owner.Focus();
                 }
 
-                Button b = sender as Button;
+                Button b = (Button)sender;
                 if (b.IsEnabled)
                 {
                     Owner.OnPreviousClick();
@@ -878,7 +878,7 @@ namespace Avalonia.Controls.Primitives
                 {
                     Owner.Focus();
                 }
-                Button b = sender as Button;
+                Button b = (Button)sender;
 
                 if (b.IsEnabled)
                 {
@@ -891,8 +891,7 @@ namespace Avalonia.Controls.Primitives
         {
             if (Owner != null)
             {
-                CalendarDayButton b = sender as CalendarDayButton;
-                if (_isMouseLeftButtonDown && b != null && b.IsEnabled && !b.IsBlackout)
+                if (_isMouseLeftButtonDown && sender is CalendarDayButton b && b.IsEnabled && !b.IsBlackout)
                 {
                     // Update the states of all buttons to be selected starting
                     // from HoverStart to b
@@ -918,7 +917,7 @@ namespace Avalonia.Controls.Primitives
                                 Debug.Assert(b.DataContext != null, "The DataContext should not be null!");
                                 Owner.UnHighlightDays();
                                 Owner.HoverEndIndex = b.Index;
-                                Owner.HoverEnd = (DateTime)b.DataContext;
+                                Owner.HoverEnd = (DateTime?)b.DataContext;
                                 // Update the States of the buttons
                                 Owner.HighlightDays();
                                 return;
@@ -931,7 +930,7 @@ namespace Avalonia.Controls.Primitives
         {
             if (_isMouseLeftButtonDown)
             {
-                CalendarDayButton b = sender as CalendarDayButton;
+                CalendarDayButton b = (CalendarDayButton)sender;
                 // The button is in Pressed state. Change the state to normal.
                 if (e.Device.Captured == b)
                     e.Device.Capture(null);
@@ -973,7 +972,7 @@ namespace Avalonia.Controls.Primitives
                     if (b.IsEnabled && !b.IsBlackout)
                     {
                         DateTime selectedDate = (DateTime)b.DataContext;
-                        Debug.Assert(selectedDate != null, "selectedDate should not be null!");
+                        Contract.Requires<ArgumentNullException>(selectedDate != null);
                         _isMouseLeftButtonDown = true;
                         // null check is added for unit tests
                         if (e != null)
@@ -1149,7 +1148,7 @@ namespace Avalonia.Controls.Primitives
                 if (_isControlPressed && Owner.SelectionMode == CalendarSelectionMode.MultipleRange)
                 {
                     CalendarDayButton b = sender as CalendarDayButton;
-                    Debug.Assert(b != null, "The sender should be a non-null CalendarDayButton!");
+                    Contract.Requires<ArgumentNullException>(b != null);
 
                     if (b.IsSelected)
                     {
@@ -1169,7 +1168,7 @@ namespace Avalonia.Controls.Primitives
         private void Month_CalendarButtonMouseDown(object sender, PointerPressedEventArgs e)
         {
             CalendarButton b = sender as CalendarButton;
-            Debug.Assert(b != null, "The sender should be a non-null CalendarDayButton!");
+            Contract.Requires<ArgumentNullException>(b != null);
 
             _isMouseLeftButtonDownYearView = true;
 
@@ -1208,7 +1207,7 @@ namespace Avalonia.Controls.Primitives
             if (_isMouseLeftButtonDownYearView)
             {
                 CalendarButton b = sender as CalendarButton;
-                Debug.Assert(b != null, "The sender should be a non-null CalendarDayButton!");
+                Contract.Requires<ArgumentNullException>(b != null);
                 UpdateYearViewSelection(b);
             }
         }
@@ -1217,7 +1216,7 @@ namespace Avalonia.Controls.Primitives
         {
             if (_isMouseLeftButtonDownYearView)
             {
-                CalendarButton b = sender as CalendarButton;
+                CalendarButton b = (CalendarButton)sender;
                 // The button is in Pressed state. Change the state to normal.
                 if (e.Device.Captured == b)
                     e.Device.Capture(null);
diff --git a/src/Avalonia.Controls/Calendar/DatePicker.cs b/src/Avalonia.Controls/Calendar/DatePicker.cs
index 418ef50b2c..08608ad359 100644
--- a/src/Avalonia.Controls/Calendar/DatePicker.cs
+++ b/src/Avalonia.Controls/Calendar/DatePicker.cs
@@ -842,7 +842,7 @@ namespace Avalonia.Controls
         private void Calendar_KeyDown(object sender, KeyEventArgs e)
         {
             Calendar c = sender as Calendar;
-            Debug.Assert(c != null, "The Calendar should not be null!");
+            Contract.Requires<ArgumentNullException>(c != null);
 
             if (!e.Handled && (e.Key == Key.Enter || e.Key == Key.Space || e.Key == Key.Escape) && c.DisplayMode == CalendarMode.Month)
             {
diff --git a/src/Avalonia.Controls/Embedding/Offscreen/OffscreenTopLevel.cs b/src/Avalonia.Controls/Embedding/Offscreen/OffscreenTopLevel.cs
index cd2da692ba..4db16c71a5 100644
--- a/src/Avalonia.Controls/Embedding/Offscreen/OffscreenTopLevel.cs
+++ b/src/Avalonia.Controls/Embedding/Offscreen/OffscreenTopLevel.cs
@@ -57,7 +57,7 @@ namespace Avalonia.Controls.Embedding.Offscreen
         Type IStyleable.StyleKey => typeof(EmbeddableControlRoot);
         public void Dispose()
         {
-            PlatformImpl.Dispose();
+            PlatformImpl?.Dispose();
         }
     }
 }
diff --git a/src/Avalonia.Controls/Platform/InProcessDragSource.cs b/src/Avalonia.Controls/Platform/InProcessDragSource.cs
index e136efe2a9..52e09aba45 100644
--- a/src/Avalonia.Controls/Platform/InProcessDragSource.cs
+++ b/src/Avalonia.Controls/Platform/InProcessDragSource.cs
@@ -62,7 +62,7 @@ namespace Avalonia.Platform
 
             RawDragEvent rawEvent = new RawDragEvent(_dragDrop, type, root, pt, _draggedData, _allowedEffects);
             var tl = root.GetSelfAndVisualAncestors().OfType<TopLevel>().FirstOrDefault();
-            tl.PlatformImpl.Input(rawEvent);
+            tl.PlatformImpl?.Input(rawEvent);
 
             var effect = GetPreferredEffect(rawEvent.Effects & _allowedEffects, modifiers);
             UpdateCursor(root, effect);
diff --git a/src/Avalonia.Themes.Default/Calendar.xaml b/src/Avalonia.Themes.Default/Calendar.xaml
index 5e4306c217..61b1224424 100644
--- a/src/Avalonia.Themes.Default/Calendar.xaml
+++ b/src/Avalonia.Themes.Default/Calendar.xaml
@@ -15,9 +15,10 @@
     <Setter Property="Template">
       <ControlTemplate>
         <StackPanel Name="Root"
-                    HorizontalAlignment="Center">
+                    HorizontalAlignment="Center"
+                    ClipToBounds="True">
 
-          <CalendarItem Name="CalendarItem"
+                    <CalendarItem Name="CalendarItem"
                         Background="{TemplateBinding Background}"
                         BorderBrush="{TemplateBinding BorderBrush}"
                         BorderThickness="{TemplateBinding BorderThickness}"
diff --git a/src/Markup/Avalonia.Markup/Data/MultiBinding.cs b/src/Markup/Avalonia.Markup/Data/MultiBinding.cs
index f6f62dcd1d..a3fa6880ac 100644
--- a/src/Markup/Avalonia.Markup/Data/MultiBinding.cs
+++ b/src/Markup/Avalonia.Markup/Data/MultiBinding.cs
@@ -10,6 +10,7 @@ using System.Reactive.Subjects;
 using Avalonia.Controls;
 using Avalonia.Data.Converters;
 using Avalonia.Metadata;
+using JetBrains.Annotations;
 
 namespace Avalonia.Data
 {
@@ -65,7 +66,7 @@ namespace Avalonia.Data
             var children = Bindings.Select(x => x.Initiate(target, null));
             var input = children.Select(x => x.Subject).CombineLatest().Select(x => ConvertValue(x, targetType));
             var mode = Mode == BindingMode.Default ?
-                targetProperty.GetMetadata(target.GetType()).DefaultBindingMode : Mode;
+                targetProperty?.GetMetadata(target.GetType()).DefaultBindingMode : Mode;
 
             switch (mode)
             {
diff --git a/src/Windows/Avalonia.Win32/SystemDialogImpl.cs b/src/Windows/Avalonia.Win32/SystemDialogImpl.cs
index e08fecbbd9..9b6bf57e92 100644
--- a/src/Windows/Avalonia.Win32/SystemDialogImpl.cs
+++ b/src/Windows/Avalonia.Win32/SystemDialogImpl.cs
@@ -54,7 +54,7 @@ namespace Avalonia.Win32
                 var fileBuffer = new char[256];
                 dialog.InitialFileName?.CopyTo(0, fileBuffer, 0, dialog.InitialFileName.Length);
 
-                string userSelectedExt = null;
+                string userSelectedExt = string.Empty;
 
 
                 var title = ToChars(dialog.Title);

From f06fa9881948fc1ea5a87e2ebb28ee6605d95d72 Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Wed, 6 Jun 2018 00:49:38 +0100
Subject: [PATCH 22/24] fix exception when carousel items set to null.

---
 src/Avalonia.Controls/Presenters/CarouselPresenter.cs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/Avalonia.Controls/Presenters/CarouselPresenter.cs b/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
index 144174e371..35deea05ec 100644
--- a/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
+++ b/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
@@ -125,8 +125,8 @@ namespace Avalonia.Controls.Presenters
                         var containers = generator.Containers.ToList();
                         generator.Clear();
                         Panel.Children.RemoveAll(containers.Select(x => x.ContainerControl));
-
-                        MoveToPage(-1, SelectedIndex >= 0 ? SelectedIndex : 0);
+                        
+                        MoveToPage(-1, SelectedIndex >= 0 ? SelectedIndex : e.NewStartingIndex);
                     }
                     break;     
             }

From 9d3a5845d7aefb7191ae62ca071414fb0936ed35 Mon Sep 17 00:00:00 2001
From: CommonGuy <m-allenspach@hotmail.com>
Date: Wed, 6 Jun 2018 09:44:25 +0200
Subject: [PATCH 23/24] Fix 404 links in readme

---
 readme.md | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/readme.md b/readme.md
index 2b26cbdd1a..4fe76a2faf 100644
--- a/readme.md
+++ b/readme.md
@@ -18,7 +18,7 @@ Avalonia is a WPF-inspired cross-platform XAML-based UI framework providing a fl
 
 ## Getting Started
 
-Avalonia [Visual Studio Extension](https://marketplace.visualstudio.com/items?itemName=AvaloniaTeam.AvaloniaforVisualStudio) contains project and control templates that will help you get started. After installing it, open "New Project" dialog in Visual Studio, choose "Avalonia" in "Visual C#" section, select "Avalonia .NET Core Application" and press OK (<a href="http://avaloniaui.net/tutorial/images/add-dialogs.png">screenshot</a>). Now you can write code and markup that will work on multiple platforms!
+Avalonia [Visual Studio Extension](https://marketplace.visualstudio.com/items?itemName=AvaloniaTeam.AvaloniaforVisualStudio) contains project and control templates that will help you get started. After installing it, open "New Project" dialog in Visual Studio, choose "Avalonia" in "Visual C#" section, select "Avalonia .NET Core Application" and press OK (<a href="http://avaloniaui.net/docs/quickstart/images/new-project-dialog.png">screenshot</a>). Now you can write code and markup that will work on multiple platforms!
 
 Avalonia is delivered via <b>NuGet</b> package manager. You can find the packages here: ([stable(ish)](https://www.nuget.org/packages/Avalonia/), [nightly](https://github.com/AvaloniaUI/Avalonia/wiki/Using-nightly-build-feed))
 
@@ -52,7 +52,7 @@ Please read the [contribution guidelines](http://avaloniaui.net/contributing/con
 ### Contributors
 
 This project exists thanks to all the people who contribute. [[Contribute](http://avaloniaui.net/contributing/contributing)].
-<a href="graphs/contributors"><img src="https://opencollective.com/Avalonia/contributors.svg?width=890&button=false" /></a>
+<a href="https://github.com/AvaloniaUI/Avalonia/graphs/contributors"><img src="https://opencollective.com/Avalonia/contributors.svg?width=890&button=false" /></a>
 
 
 ### Backers

From 9911fff84de01873a61da067dd389d71701fe510 Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Thu, 7 Jun 2018 15:11:09 +0100
Subject: [PATCH 24/24] fix carousel presenter and add unit test for condition.

---
 .../Presenters/CarouselPresenter.cs           | 16 ++++++++-
 .../CarouselTests.cs                          | 35 +++++++++++++++++++
 2 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/src/Avalonia.Controls/Presenters/CarouselPresenter.cs b/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
index 35deea05ec..e438843078 100644
--- a/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
+++ b/src/Avalonia.Controls/Presenters/CarouselPresenter.cs
@@ -125,8 +125,22 @@ namespace Avalonia.Controls.Presenters
                         var containers = generator.Containers.ToList();
                         generator.Clear();
                         Panel.Children.RemoveAll(containers.Select(x => x.ContainerControl));
+
+                        var newIndex = SelectedIndex;
+
+                        if(SelectedIndex < 0)
+                        {
+                            if(Items != null && Items.Count() > 0)
+                            {
+                                newIndex = 0;
+                            }
+                            else
+                            {
+                                newIndex = -1;
+                            }
+                        }
                         
-                        MoveToPage(-1, SelectedIndex >= 0 ? SelectedIndex : e.NewStartingIndex);
+                        MoveToPage(-1, newIndex);
                     }
                     break;     
             }
diff --git a/tests/Avalonia.Controls.UnitTests/CarouselTests.cs b/tests/Avalonia.Controls.UnitTests/CarouselTests.cs
index df61698209..f36e5864f6 100644
--- a/tests/Avalonia.Controls.UnitTests/CarouselTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/CarouselTests.cs
@@ -170,6 +170,41 @@ namespace Avalonia.Controls.UnitTests
             Assert.Equal("Bar", ((TextBlock)child).Text);
         }
 
+        [Fact]
+        public void Selected_Index_Changes_To_When_Items_Assigned_Null()
+        {
+            var items = new ObservableCollection<string>
+            {
+               "Foo",
+               "Bar",
+               "FooBar"
+            };
+
+            var target = new Carousel
+            {
+                Template = new FuncControlTemplate<Carousel>(CreateTemplate),
+                Items = items,
+                IsVirtualized = false
+            };
+
+            target.ApplyTemplate();
+            target.Presenter.ApplyTemplate();
+
+            Assert.Single(target.GetLogicalChildren());
+
+            var child = target.GetLogicalChildren().Single();
+
+            Assert.IsType<TextBlock>(child);
+            Assert.Equal("Foo", ((TextBlock)child).Text);
+
+            target.Items = null;
+
+            var numChildren = target.GetLogicalChildren().Count();
+
+            Assert.Equal(0, numChildren);
+            Assert.Equal(-1, target.SelectedIndex);
+        }
+
         [Fact]
         public void Selected_Index_Is_Maintained_Carousel_Created_With_Non_Zero_SelectedIndex()
         {