Converted GazeInteraction project from C++ to C#. (#3427)

## Unifies Toolkit language to be only C#.

## PR Type
What kind of change does this PR introduce?
<!-- Please uncomment one or more that apply to this PR. -->

- Bugfix 
- Feature 
- Refactoring (no functional changes, no api changes) 

## What is the current behavior?
C++, boo.


## What is the new behavior?
All C# 🦙🎉



## PR Checklist

Please check if your PR fulfills the following requirements:

- [X] Tested code with current [supported SDKs](../readme.md#supported)
- [ ] Pull Request has been submitted to the documentation repository [instructions](..\contributing.md#docs). Link: <!-- docs PR link -->
- [ ] Sample in sample app has been added / updated (for bug fixes / features)
    - [ ] Icon has been created (if new sample) following the [Thumbnail Style Guide and templates](https://github.com/windows-toolkit/WindowsCommunityToolkit-design-assets)
- [ ] Tests for the changes have been added (for bug fixes / features) (if applicable)
- [X] Header has been added to all new source files (run *build/UpdateHeaders.bat*)
- [ ] Contains **NO** breaking changes

This is not exporting WinMDs, so C++ devs will be stuck on 6.x, and this is expected.

Author: msftbot[bot]

GazeInputTest/GazeInputTest.csproj

@@ -157,8 +157,8 @@
     </PackageReference>
   </ItemGroup>
   <ItemGroup>
-    <ProjectReference Include="..\Microsoft.Toolkit.UWP.Input.GazeInteraction\Microsoft.Toolkit.Uwp.Input.GazeInteraction.vcxproj">
-      <Project>{a5e98964-45b1-442d-a07a-298a3221d81e}</Project>
+    <ProjectReference Include="..\Microsoft.Toolkit.Uwp.Input.GazeInteraction\Microsoft.Toolkit.Uwp.Input.GazeInteraction.csproj">
+      <Project>{5bf75694-798a-43a0-8150-415de195359c}</Project>
       <Name>Microsoft.Toolkit.Uwp.Input.GazeInteraction</Name>
     </ProjectReference>
   </ItemGroup>

GazeInputTest/Properties/AssemblyInfo.cs

@@ -5,7 +5,7 @@
 using System.Reflection;
 using System.Runtime.InteropServices;
 
-// General Information about an assembly is controlled through the following 
+// General Information about an assembly is controlled through the following
 // set of attributes. Change these attribute values to modify the information
 // associated with an assembly.
 [assembly: AssemblyTitle("GazeInputTest")]
@@ -20,13 +20,13 @@
 // Version information for an assembly consists of the following four values:
 //
 //      Major Version
-//      Minor Version 
+//      Minor Version
 //      Build Number
 //      Revision
 //
-// You can specify all the values or you can default the Build and Revision Numbers 
+// You can specify all the values or you can default the Build and Revision Numbers
 // by using the '*' as shown below:
 // [assembly: AssemblyVersion("1.0.*")]
-//[assembly: AssemblyVersion("1.0.0.0")]
-//[assembly: AssemblyFileVersion("1.0.0.0")]
+// [assembly: AssemblyVersion("1.0.0.0")]
+// [assembly: AssemblyFileVersion("1.0.0.0")]
 [assembly: ComVisible(false)]

Microsoft.Toolkit.Uwp.Input.GazeInteraction/ComboBoxItemGazeTargetItem.cs

@@ -0,0 +1,36 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Windows.UI.Xaml;
+using Windows.UI.Xaml.Automation.Peers;
+using Windows.UI.Xaml.Controls;
+
+namespace Microsoft.Toolkit.Uwp.Input.GazeInteraction
+{
+    internal class ComboBoxItemGazeTargetItem : GazeTargetItem
+    {
+        internal ComboBoxItemGazeTargetItem(UIElement element)
+            : base(element)
+        {
+        }
+
+        internal override void Invoke()
+        {
+            var peer = FrameworkElementAutomationPeer.FromElement(TargetElement);
+            var comboBoxItemAutomationPeer = peer as ComboBoxItemAutomationPeer;
+            var comboBoxItem = (ComboBoxItem)comboBoxItemAutomationPeer.Owner;
+
+            AutomationPeer ancestor = comboBoxItemAutomationPeer;
+            var comboBoxAutomationPeer = ancestor as ComboBoxAutomationPeer;
+            while (comboBoxAutomationPeer == null)
+            {
+                ancestor = ancestor.Navigate(AutomationNavigationDirection.Parent) as AutomationPeer;
+                comboBoxAutomationPeer = ancestor as ComboBoxAutomationPeer;
+            }
+
+            comboBoxItem.IsSelected = true;
+            comboBoxAutomationPeer.Collapse();
+        }
+    }
+}

Microsoft.Toolkit.Uwp.Input.GazeInteraction/DwellInvokedRoutedEventArgs.cs

@@ -0,0 +1,19 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.ComponentModel;
+
+namespace Microsoft.Toolkit.Uwp.Input.GazeInteraction
+{
+    /// <summary>
+    /// This parameter is passed to the GazeElement::Invoked event and allows
+    /// the application to prevent default invocation when the user dwells on a control
+    /// </summary>
+    public sealed class DwellInvokedRoutedEventArgs : HandledEventArgs
+    {
+        internal DwellInvokedRoutedEventArgs()
+        {
+        }
+    }
+}

Microsoft.Toolkit.Uwp.Input.GazeInteraction/DwellInvokedRoutedEventArgs.h

@@ -0,0 +1,31 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.ComponentModel;
+
+namespace Microsoft.Toolkit.Uwp.Input.GazeInteraction
+{
+    /// <summary>
+    /// This parameter is passed to the GazeElement.DwellProgressFeedback event. The event is fired to inform the application of the user's progress towards completing dwelling on a control
+    /// </summary>
+    public sealed class DwellProgressEventArgs : HandledEventArgs
+    {
+        /// <summary>
+        /// Gets an enum that reflects the current state of dwell progress
+        /// </summary>
+        public DwellProgressState State { get; }
+
+        /// <summary>
+        /// Gets a value between 0 and 1 that reflects the fraction of progress towards completing dwell
+        /// </summary>
+        public double Progress { get; }
+
+        internal DwellProgressEventArgs(DwellProgressState state, TimeSpan elapsedDuration, TimeSpan triggerDuration)
+        {
+            State = state;
+            Progress = ((double)elapsedDuration.Ticks) / triggerDuration.Ticks;
+        }
+    }
+}

Microsoft.Toolkit.Uwp.Input.GazeInteraction/DwellProgressEventArgs.cs

@@ -0,0 +1,32 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Microsoft.Toolkit.Uwp.Input.GazeInteraction
+{
+    /// <summary>
+    /// An enum that reflects the current state of progress towards dwell when a user is focused on a control
+    /// </summary>
+    public enum DwellProgressState
+    {
+        /// <summary>
+        /// User is not looking at the control
+        /// </summary>
+        Idle,
+
+        /// <summary>
+        /// Gaze has entered control but we're not yet showing progress.
+        /// </summary>
+        Fixating,
+
+        /// <summary>
+        /// User is continuing to focus on a control with an intent to dwell and invoke
+        /// </summary>
+        Progressing,
+
+        /// <summary>
+        /// User has completed dwelling on a control
+        /// </summary>
+        Complete
+    }
+}

Microsoft.Toolkit.Uwp.Input.GazeInteraction/DwellProgressEventArgs.h

@@ -0,0 +1,35 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Windows.UI.Xaml;
+using Windows.UI.Xaml.Automation;
+using Windows.UI.Xaml.Automation.Peers;
+using Windows.UI.Xaml.Automation.Provider;
+
+namespace Microsoft.Toolkit.Uwp.Input.GazeInteraction
+{
+    internal class ExpandCollapsePatternGazeTargetItem : GazeTargetItem
+    {
+        internal ExpandCollapsePatternGazeTargetItem(UIElement element)
+            : base(element)
+        {
+        }
+
+        internal override void Invoke()
+        {
+            var peer = FrameworkElementAutomationPeer.FromElement(TargetElement);
+            var provider = peer.GetPattern(PatternInterface.ExpandCollapse) as IExpandCollapseProvider;
+            switch (provider.ExpandCollapseState)
+            {
+                case ExpandCollapseState.Collapsed:
+                    provider.Expand();
+                    break;
+
+                case ExpandCollapseState.Expanded:
+                    provider.Collapse();
+                    break;
+            }
+        }
+    }
+}