chore: Additional required dependencies

src/Uno.UI/DirectUI/ElevationHelper.cs

@@ -0,0 +1,58 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License. See LICENSE in the project root for license information.
+// MUX Reference dxaml\phone\lib\ElevationHelper.cpp, tag winui3/release/1.5.4, commit 98a60c8
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Numerics;
+using System.Text;
+using System.Threading.Tasks;
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Media;
+
+namespace DirectUI;
+
+internal static class ElevationHelper
+{
+	//// The initial Z offset applied to all elevated controls
+	//private const float s_elevationBaseDepth = 32.0f;
+	//// This additional Z offset will be applied for each tier of logically parented controls
+	//private const float s_elevationIterativeDepth = 8.0f;
+
+	//internal static void ApplyThemeShadow(UIElement target)
+	//{
+	//	var themeShadow = new ThemeShadow();
+	//	target.Shadow = themeShadow;
+	//}
+
+	//internal static void ApplyElevationEffect(UIElement target, int depth)
+	//{
+	//	// Calculate the Z offset based on the depth of the shadow
+	//	var calculatedZDepth = s_elevationBaseDepth + (depth * s_elevationIterativeDepth);
+
+	//	var endTranslation = new Vector3(0.0f, 0.0f, calculatedZDepth);
+
+	//	// Apply a translation facade value
+	//	target.Translation = endTranslation;
+
+	//	// Apply a shadow to the element
+	//	ApplyThemeShadow(target);
+	//}
+
+	// Move the control forward in Z and apply a shadow effect to it.
+	// If the control is part of a tier of elevated controls (for example a MenuFlyoutSubItem),
+	// you may provide an additional "depth" value that provides an additional Z offset.
+	internal static void ApplyElevationEffect(UIElement target, int depth = 0, int? baseElevation = null)
+	{
+	}
+
+	// Remove any shadow applied with ApplyElevationEffect
+	internal static void ClearElevationEffect(UIElement target)
+	{
+	}
+
+	// Checks if the "IsDefaultShadowEnabled" resource is defined as True or not, determining
+	// if a control should enable a shadow by default.
+	internal static bool IsDefaultShadowEnabled(FrameworkElement resourceTarget) => false;
+}

src/Uno.UI/UI/Xaml/Controls/ComboBox/ComboBox.Properties.cs

@@ -208,11 +208,6 @@ public Style TextBoxStyle
 			typeof(ComboBox),
 			new FrameworkPropertyMetadata(null));
 
-	/// <summary>
-	/// Occurs when the user submits some text that does not correspond to an item in the ComboBox dropdown list.
-	/// </summary>
-	public event TypedEventHandler<ComboBox, ComboBoxTextSubmittedEventArgs> TextSubmitted;
-
 	/// <summary>
 	/// Occurs when the drop-down portion of the ComboBox closes.
 	/// </summary>
@@ -222,4 +217,9 @@ public Style TextBoxStyle
 	/// Occurs when the drop-down portion of the ComboBox opens.
 	/// </summary>
 	public event EventHandler<object> DropDownOpened;
+
+	/// <summary>
+	/// Occurs when the user submits some text that does not correspond to an item in the ComboBox dropdown list.
+	/// </summary>
+	public event TypedEventHandler<ComboBox, ComboBoxTextSubmittedEventArgs> TextSubmitted;
 }

src/Uno.UI/UI/Xaml/Controls/ComboBox/ComboBox.custom.cs

@@ -863,6 +863,8 @@ Point getChildLocation()
 #endif
 
 			child.Arrange(frame);
+
+			combo.m_bPopupHasBeenArrangedOnce = true;
 		}
 	}
 }

src/Uno.UI/UI/Xaml/Controls/ComboBox/ComboBox.partial.h.mux.cs

@@ -4,6 +4,7 @@
 using System.Text;
 using System.Threading.Tasks;
 using Microsoft.UI.Xaml.Documents;
+using Microsoft.UI.Xaml.Media.Animation;
 using Uno.Disposables;
 using Uno.UI.Xaml.Input;
 using Windows.Foundation;
@@ -12,10 +13,18 @@ namespace Microsoft.UI.Xaml.Controls;
 
 partial class ComboBox
 {
+#pragma warning disable CS0067 // Unused only in reference API.
+#pragma warning disable CS0649 // Unused only in reference API.
+#pragma warning disable CS0169 // Unused only in reference API.
+#pragma warning disable CS0168 // Unused only in reference API.
+#pragma warning disable CS0414 // Unused only in reference API.
 	internal bool IsSearchResultIndexSet() => m_searchResultIndexSet;
 
 	internal int GetSearchResultIndex() => m_searchResultIndex;
 
+	private bool m_bIsPopupPannable;
+	private bool m_bShouldCarousel;
+	private bool m_bShouldCenterSelectedItem;
 	private bool m_handledGamepadOrRemoteKeyDown;
 	private bool m_ignoreCancelKeyDowns;
 	private bool m_isEditModeConfigured;
@@ -44,12 +53,18 @@ partial class ComboBox
 	// Editable ComboBox is designed to set the focus on TextBox when ComboBox is focused, there are some cases when we don't want
 	// this behavior eg(Shift+Tab).
 	private bool m_shouldMoveFocusToTextBox;
-	private bool m_isClosingDueToCancel;
+	private bool m_isExpanded;
+	private bool m_isOverlayVisible;
 	private bool m_restoreIndexSet;
+	private bool m_isClosingDueToCancel;
 
 	private bool m_IsPointerOverDropDownOverlay;
 
 	private InputDeviceType m_inputDeviceTypeUsedToOpen;
+	private InputDeviceType m_previousInputDeviceTypeUsedToOpen;
+
+	private FrameworkElement m_tpElementPopupChild;
+	private FrameworkElement m_tpElementPopupContent;
 
 	private readonly SerialDisposable m_spEditableTextPointerPressedEventHandler = new();
 	private readonly SerialDisposable m_spEditableTextTappedEventHandler = new();
@@ -65,6 +80,7 @@ partial class ComboBox
 	private TextBlock m_tpEditableContentPresenterTextBlock;
 	private ComboBoxItem m_tpSwappedOutComboBoxItem;
 
+	private Storyboard m_tpClosedStoryboard;
 	private DependencyObject m_tpGeneratedContainerForContentPresenter;
 	private int m_iLastGeneratedItemIndexforFaceplate;
 	private object m_customValueRef;
@@ -78,6 +94,7 @@ partial class ComboBox
 
 	private bool IsFullMode => IsSmallFormFactor && m_itemCount > s_itemCountThreshold;
 
+	private IAsyncInfo m_tpAsyncSelectionInfo;
 	private int m_itemCount;
 
 	private int m_indexToRestoreOnCancel = -1;