From 0d896b38471265d238127e974f64f86384068a9f Mon Sep 17 00:00:00 2001
From: Takoooooo <tako0qq@gmail.com>
Date: Fri, 11 Feb 2022 12:28:10 +0200
Subject: [PATCH] Improove nullable annotations.

---
 src/Avalonia.Controls/DateTimePickers/DateTimePickerPanel.cs | 2 +-
 src/Avalonia.Controls/Generators/IItemContainerGenerator.cs  | 2 +-
 src/Avalonia.Controls/Generators/ItemContainerGenerator.cs   | 2 +-
 src/Avalonia.Controls/Presenters/ItemVirtualizer.cs          | 2 +-
 src/Avalonia.Controls/Presenters/ItemVirtualizerSimple.cs    | 2 +-
 src/Avalonia.Controls/Presenters/ItemsPresenter.cs           | 2 +-
 src/Avalonia.Controls/Primitives/ILogicalScrollable.cs       | 2 +-
 src/Avalonia.Controls/VirtualizingStackPanel.cs              | 2 +-
 8 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/Avalonia.Controls/DateTimePickers/DateTimePickerPanel.cs b/src/Avalonia.Controls/DateTimePickers/DateTimePickerPanel.cs
index 10b7f9bdf9..5948d81810 100644
--- a/src/Avalonia.Controls/DateTimePickers/DateTimePickerPanel.cs
+++ b/src/Avalonia.Controls/DateTimePickers/DateTimePickerPanel.cs
@@ -560,7 +560,7 @@ namespace Avalonia.Controls.Primitives
 
         public bool BringIntoView(IControl target, Rect targetRect) { return false; }
 
-        public IControl? GetControlInDirection(NavigationDirection direction, IControl from) { return null; }
+        public IControl? GetControlInDirection(NavigationDirection direction, IControl? from) { return null; }
 
         public void RaiseScrollInvalidated(EventArgs e)
         {
diff --git a/src/Avalonia.Controls/Generators/IItemContainerGenerator.cs b/src/Avalonia.Controls/Generators/IItemContainerGenerator.cs
index dd4c6561c2..70d9dbec08 100644
--- a/src/Avalonia.Controls/Generators/IItemContainerGenerator.cs
+++ b/src/Avalonia.Controls/Generators/IItemContainerGenerator.cs
@@ -97,6 +97,6 @@ namespace Avalonia.Controls.Generators
         /// </summary>
         /// <param name="container">The container.</param>
         /// <returns>The index of the container, or -1 if not found.</returns>
-        int IndexFromContainer(IControl container);
+        int IndexFromContainer(IControl? container);
     }
 }
diff --git a/src/Avalonia.Controls/Generators/ItemContainerGenerator.cs b/src/Avalonia.Controls/Generators/ItemContainerGenerator.cs
index d02eaffeb2..79a9e16879 100644
--- a/src/Avalonia.Controls/Generators/ItemContainerGenerator.cs
+++ b/src/Avalonia.Controls/Generators/ItemContainerGenerator.cs
@@ -158,7 +158,7 @@ namespace Avalonia.Controls.Generators
         }
 
         /// <inheritdoc/>
-        public int IndexFromContainer(IControl container)
+        public int IndexFromContainer(IControl? container)
         {
             foreach (var i in _containers)
             {
diff --git a/src/Avalonia.Controls/Presenters/ItemVirtualizer.cs b/src/Avalonia.Controls/Presenters/ItemVirtualizer.cs
index 343c72f742..4c412e9a41 100644
--- a/src/Avalonia.Controls/Presenters/ItemVirtualizer.cs
+++ b/src/Avalonia.Controls/Presenters/ItemVirtualizer.cs
@@ -254,7 +254,7 @@ namespace Avalonia.Controls.Presenters
         /// <param name="direction">The movement direction.</param>
         /// <param name="from">The control from which movement begins.</param>
         /// <returns>The control.</returns>
-        public virtual IControl? GetControlInDirection(NavigationDirection direction, IControl from)
+        public virtual IControl? GetControlInDirection(NavigationDirection direction, IControl? from)
         {
             return null;
         }
diff --git a/src/Avalonia.Controls/Presenters/ItemVirtualizerSimple.cs b/src/Avalonia.Controls/Presenters/ItemVirtualizerSimple.cs
index 361febf305..39a512a773 100644
--- a/src/Avalonia.Controls/Presenters/ItemVirtualizerSimple.cs
+++ b/src/Avalonia.Controls/Presenters/ItemVirtualizerSimple.cs
@@ -226,7 +226,7 @@ namespace Avalonia.Controls.Presenters
             InvalidateScroll();
         }
 
-        public override IControl? GetControlInDirection(NavigationDirection direction, IControl from)
+        public override IControl? GetControlInDirection(NavigationDirection direction, IControl? from)
         {
             var generator = Owner.ItemContainerGenerator;
             var panel = VirtualizingPanel;
diff --git a/src/Avalonia.Controls/Presenters/ItemsPresenter.cs b/src/Avalonia.Controls/Presenters/ItemsPresenter.cs
index 2c04b03faf..265704ceaa 100644
--- a/src/Avalonia.Controls/Presenters/ItemsPresenter.cs
+++ b/src/Avalonia.Controls/Presenters/ItemsPresenter.cs
@@ -117,7 +117,7 @@ namespace Avalonia.Controls.Presenters
         }
 
         /// <inheritdoc/>
-        IControl? ILogicalScrollable.GetControlInDirection(NavigationDirection direction, IControl from)
+        IControl? ILogicalScrollable.GetControlInDirection(NavigationDirection direction, IControl? from)
         {
             return Virtualizer?.GetControlInDirection(direction, from);
         }
diff --git a/src/Avalonia.Controls/Primitives/ILogicalScrollable.cs b/src/Avalonia.Controls/Primitives/ILogicalScrollable.cs
index 2be91c046e..0b3791be3a 100644
--- a/src/Avalonia.Controls/Primitives/ILogicalScrollable.cs
+++ b/src/Avalonia.Controls/Primitives/ILogicalScrollable.cs
@@ -64,7 +64,7 @@ namespace Avalonia.Controls.Primitives
         /// <param name="direction">The movement direction.</param>
         /// <param name="from">The control from which movement begins.</param>
         /// <returns>The control.</returns>
-        IControl? GetControlInDirection(NavigationDirection direction, IControl from);
+        IControl? GetControlInDirection(NavigationDirection direction, IControl? from);
 
         /// <summary>
         /// Raises the <see cref="ScrollInvalidated"/> event.
diff --git a/src/Avalonia.Controls/VirtualizingStackPanel.cs b/src/Avalonia.Controls/VirtualizingStackPanel.cs
index f27568694d..93fbf6d17b 100644
--- a/src/Avalonia.Controls/VirtualizingStackPanel.cs
+++ b/src/Avalonia.Controls/VirtualizingStackPanel.cs
@@ -133,7 +133,7 @@ namespace Avalonia.Controls
 
             if (logicalScrollable?.IsLogicalScrollEnabled == true)
             {
-                return logicalScrollable.GetControlInDirection(direction, from!);
+                return logicalScrollable.GetControlInDirection(direction, from);
             }
             else
             {