From 40f7f239db2b598d34e6be8e0796c5053cb7c25c Mon Sep 17 00:00:00 2001
From: Stephen Quan <squan@esri.com>
Date: Fri, 14 Feb 2025 23:29:27 +1100
Subject: [PATCH 1/4] Change the Expander mechanism to use
 VerticalStackLayout.HeightRequest instead of Content.IsVisible so that the
 user can use animate expanding/collapsing modes.

---
 .../Pages/Views/Expander/ExpanderPage.xaml    |  15 +-
 .../Pages/Views/Expander/ExpanderPage.xaml.cs |  13 +-
 .../Pages/Views/Expander/ExpanderPageCS.cs    |  16 ++-
 .../Views/Expander/Expander.shared.cs         | 136 ++++++++++++------
 4 files changed, 124 insertions(+), 56 deletions(-)

diff --git a/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPage.xaml b/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPage.xaml
index 15ddcb5973..b35365fd6e 100644
--- a/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPage.xaml
+++ b/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPage.xaml
@@ -17,7 +17,7 @@
 
             <Label Text="Simple expander" FontSize="24" FontAttributes="Bold"/>
 
-            <mct:Expander>
+            <mct:Expander PropertyChanged="AnimateExpander">
                 <mct:Expander.Header>
                     <Label Text="Simple Expander (Tap Me)" FontSize="16" FontAttributes="Bold"/>
                 </mct:Expander.Header>
@@ -32,12 +32,12 @@
 
             <Label Text="Multi-level expander" FontSize="24" FontAttributes="Bold"/>
 
-            <mct:Expander Direction="Up">
+            <mct:Expander Direction="Up" PropertyChanged="AnimateExpander">
                 <mct:Expander.Header>
                     <Label Text="Multi-Level Expander (Tap Me)" FontSize="16" FontAttributes="Bold"/>
                 </mct:Expander.Header>
                 <mct:Expander.Content>
-                    <mct:Expander Direction="Down" BackgroundColor="LightGray">
+                    <mct:Expander Direction="Down" BackgroundColor="LightGray" PropertyChanged="AnimateExpander">
                         <mct:Expander.Header>
                             <Label Text="Nested Expander (Tap Me)" FontSize="14" FontAttributes="Bold"/>
                         </mct:Expander.Header>
@@ -56,7 +56,8 @@
                     <DataTemplate>
                         <ViewCell>
                             <mct:Expander x:DataType="sample:ContentCreator"
-                                          ExpandedChanged="Expander_ExpandedChanged">
+                                          ExpandedChanged="Expander_ExpandedChanged"
+                                          PropertyChanged="AnimateExpander">
                                 <mct:Expander.Header>
                                     <Label Text="{Binding Name}"/>
                                 </mct:Expander.Header>
@@ -80,7 +81,8 @@
                 <CollectionView.ItemTemplate>
                     <DataTemplate>
                         <mct:Expander x:DataType="sample:ContentCreator"
-                                      ExpandedChanged="Expander_ExpandedChanged">
+                                      ExpandedChanged="Expander_ExpandedChanged"
+                                      PropertyChanged="AnimateExpander">
                             <mct:Expander.Header>
                                 <Label Text="{Binding Name}"/>
                             </mct:Expander.Header>
@@ -109,7 +111,8 @@
                 <CollectionView.ItemTemplate>
                     <DataTemplate>
                         <mct:Expander x:DataType="sample:ContentCreator"
-                                      ExpandedChanged="Expander_ExpandedChanged">
+                                      ExpandedChanged="Expander_ExpandedChanged"
+                                      PropertyChanged="AnimateExpander">
                             <mct:Expander.Header>
                                 <Label Text="{Binding Name}"/>
                             </mct:Expander.Header>
diff --git a/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPage.xaml.cs b/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPage.xaml.cs
index 9239102530..1e86b4023c 100644
--- a/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPage.xaml.cs
+++ b/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPage.xaml.cs
@@ -16,6 +16,7 @@ public ExpanderPage(ExpanderViewModel viewModel) : base(viewModel)
 	async void Expander_ExpandedChanged(object sender, Core.ExpandedChangedEventArgs e)
 	{
 		var collapsedText = e.IsExpanded ? "expanded" : "collapsed";
+
 		await Toast.Make($"Expander is {collapsedText}").Show(CancellationToken.None);
 	}
 
@@ -23,4 +24,14 @@ async void GoToCSharpSampleClicked(object sender, EventArgs e)
 	{
 		await Navigation.PushAsync(new ExpanderPageCS());
 	}
-}
\ No newline at end of file
+
+	async void AnimateExpander(object sender, System.ComponentModel.PropertyChangedEventArgs e)
+	{
+		if (e.PropertyName == CommunityToolkit.Maui.Views.Expander.IsExpandedProperty.PropertyName)
+		{
+			CommunityToolkit.Maui.Views.Expander expander = (CommunityToolkit.Maui.Views.Expander)sender;
+			expander.ContentHeight = expander.IsExpanded ? expander.MinimumContentHeight : expander.MaximumContentHeight;
+			await expander.ContentHeightTo(expander.IsExpanded ? expander.MaximumContentHeight : expander.MinimumContentHeight, 250, Easing.CubicInOut);
+		}
+	}
+}
diff --git a/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPageCS.cs b/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPageCS.cs
index 4725207cd2..055d4999b7 100644
--- a/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPageCS.cs
+++ b/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPageCS.cs
@@ -16,6 +16,8 @@ public ExpanderPageCS()
 
 		Title = "Expander Page, C# UI";
 
+		Expander expander;
+
 		Content = new VerticalStackLayout()
 		{
 			Spacing = 12,
@@ -31,7 +33,7 @@ public ExpanderPageCS()
 					.CenterHorizontal().TextCenter()
 					.Assign(out Picker picker),
 
-				new Expander
+				(expander = new Expander
 				{
 					Header = new Label()
 								.Text("Expander\n(Tap Me)")
@@ -60,7 +62,17 @@ public ExpanderPageCS()
 						static (Picker picker) => picker.SelectedIndex,
 						source: picker,
 						convert: (int selectedIndex) => Enum.IsDefined(typeof(ExpandDirection), selectedIndex) ? (ExpandDirection)selectedIndex : default)
+				 )
 			 }
 		};
+
+		expander.PropertyChanged += async (s, e) =>
+		{
+			if (e.PropertyName == Expander.IsExpandedProperty.PropertyName)
+			{
+				expander.ContentHeight = expander.IsExpanded ? expander.MinimumContentHeight : expander.MaximumContentHeight;
+				await expander.ContentHeightTo(expander.IsExpanded ? expander.MaximumContentHeight : expander.MinimumContentHeight, 250, Easing.CubicInOut);
+			}
+		};
 	}
-}
\ No newline at end of file
+}
diff --git a/src/CommunityToolkit.Maui/Views/Expander/Expander.shared.cs b/src/CommunityToolkit.Maui/Views/Expander/Expander.shared.cs
index cad239f1e3..0f01daa07d 100644
--- a/src/CommunityToolkit.Maui/Views/Expander/Expander.shared.cs
+++ b/src/CommunityToolkit.Maui/Views/Expander/Expander.shared.cs
@@ -23,6 +23,10 @@ public static readonly BindableProperty DirectionProperty
 		= BindableProperty.Create(nameof(Direction), typeof(ExpandDirection), typeof(Expander), ExpandDirection.Down, propertyChanged: OnDirectionPropertyChanged);
 
 	readonly WeakEventManager tappedEventManager = new();
+	readonly Grid contentGrid;
+	readonly ContentView headerContentView;
+	readonly VerticalStackLayout bodyLayout;
+	readonly ContentView bodyContentView;
 
 	/// <summary>
 	/// Initialize a new instance of <see cref="Expander"/>.
@@ -32,16 +36,90 @@ public Expander()
 		HandleHeaderTapped = ResizeExpanderInItemsView;
 		HeaderTapGestureRecognizer.Tapped += OnHeaderTapGestureRecognizerTapped;
 
-		base.Content = new Grid
+		base.Content = contentGrid = new Grid
 		{
 			RowDefinitions =
 			{
 				new RowDefinition(GridLength.Auto),
 				new RowDefinition(GridLength.Auto)
+			},
+			Children =
+			{
+				(headerContentView = new ContentView()),
+				(bodyLayout = new VerticalStackLayout()
+				{
+					HeightRequest = 1,
+					MinimumHeightRequest = 1,
+					Padding = new Thickness(0, 1, 0, 0),
+					Children = { (bodyContentView = new ContentView()) }
+				})
+			}
+		};
+
+		contentGrid.SetRow(headerContentView, 0);
+		contentGrid.SetRow(bodyLayout, 1);
+
+		headerContentView.GestureRecognizers.Add(HeaderTapGestureRecognizer);
+
+		bodyContentView.PropertyChanged += (s, e) =>
+		{
+			if (e.PropertyName == nameof(ContentView.Height))
+			{
+				if (IsExpanded)
+				{
+					ContentHeight = bodyContentView.Height + 1;
+				}
+				OnPropertyChanged(nameof(MaximumContentHeight));
 			}
 		};
 	}
 
+	/// <summary>
+	/// Controls the visibility of the content inside the <see cref="Expander"/>.
+	/// </summary>
+	public double ContentHeight
+	{
+		get => bodyLayout.HeightRequest;
+		set
+		{
+			double newHeight = Math.Max(Math.Min(value, MaximumContentHeight), MinimumContentHeight);
+			if (bodyLayout.Height != newHeight)
+			{
+				bodyLayout.HeightRequest = newHeight;
+				OnPropertyChanged(nameof(ContentHeight));
+			}
+		}
+	}
+
+	/// <summary>
+	/// The height of the content inside the <see cref="Expander"/> when it is collapsed.
+	/// </summary>
+	public double MinimumContentHeight => bodyLayout.MinimumHeightRequest;
+
+	/// <summary>
+	/// The height of the content inside the <see cref="Expander"/> when it is expanded.
+	/// </summary>
+	public double MaximumContentHeight => bodyContentView.Height + 1;
+
+	/// <summary>
+	/// Animates the expanding or collapsing of the content inside the <see cref="Expander"/>.
+	/// </summary>
+	/// <param name="value">The final height of the content.</param>
+	/// <param name="length">The time, in milliseconds, over which to animate the transition. The default is 250.</param>
+	/// <param name="easing">The easing function to use for the animation.</param>
+	/// <returns>A <see cref="Task"/> containing a <see cref="bool"/> value which indicates whether the animation was canceled. <see langword="true"/> indicates that the animation was canceled. <see langword="false"/> indicates that the animation ran to completion.</returns>
+	public Task<bool> ContentHeightTo(double value, uint length = 250, Easing? easing = null)
+	{
+		if (easing == null)
+		{
+			easing = Easing.Linear;
+		}
+		var tcs = new TaskCompletionSource<bool>();
+		var animation = new Animation(v => ContentHeight = v, ContentHeight, value, easing);
+		animation.Commit(this, nameof(ContentHeightTo), 16, length, finished: (f, a) => tcs.SetResult(a));
+		return tcs.Task;
+	}
+
 	/// <summary>
 	///	Triggered when the value of <see cref="IsExpanded"/> changes
 	/// </summary>
@@ -77,23 +155,12 @@ public ExpandDirection Direction
 		}
 	}
 
-	Grid ContentGrid => (Grid)base.Content;
-
 	static void OnContentPropertyChanged(BindableObject bindable, object oldValue, object newValue)
 	{
 		var expander = (Expander)bindable;
 		if (newValue is View view)
 		{
-			view.SetBinding(IsVisibleProperty, new Binding(nameof(IsExpanded), source: expander));
-
-			expander.ContentGrid.Remove(oldValue);
-			expander.ContentGrid.Add(newValue);
-			expander.ContentGrid.SetRow(view, expander.Direction switch
-			{
-				ExpandDirection.Down => 1,
-				ExpandDirection.Up => 0,
-				_ => throw new NotSupportedException($"{nameof(ExpandDirection)} {expander.Direction} is not yet supported")
-			});
+			expander.bodyContentView.Content = view;
 		}
 	}
 
@@ -102,17 +169,7 @@ static void OnHeaderPropertyChanged(BindableObject bindable, object oldValue, ob
 		var expander = (Expander)bindable;
 		if (newValue is View view)
 		{
-			expander.SetHeaderGestures(view);
-
-			expander.ContentGrid.Remove(oldValue);
-			expander.ContentGrid.Add(newValue);
-
-			expander.ContentGrid.SetRow(view, expander.Direction switch
-			{
-				ExpandDirection.Down => 0,
-				ExpandDirection.Up => 1,
-				_ => throw new NotSupportedException($"{nameof(ExpandDirection)} {expander.Direction} is not yet supported")
-			});
+			expander.headerContentView.Content = view;
 		}
 	}
 
@@ -126,21 +183,16 @@ static void OnDirectionPropertyChanged(BindableObject bindable, object oldValue,
 
 	void HandleDirectionChanged(ExpandDirection expandDirection)
 	{
-		if (Header is null || Content is null)
-		{
-			return;
-		}
-
 		switch (expandDirection)
 		{
 			case ExpandDirection.Down:
-				ContentGrid.SetRow(Header, 0);
-				ContentGrid.SetRow(Content, 1);
+				contentGrid.SetRow(headerContentView, 0);
+				contentGrid.SetRow(bodyLayout, 1);
 				break;
 
 			case ExpandDirection.Up:
-				ContentGrid.SetRow(Header, 1);
-				ContentGrid.SetRow(Content, 0);
+				contentGrid.SetRow(headerContentView, 1);
+				contentGrid.SetRow(bodyLayout, 0);
 				break;
 
 			default:
@@ -148,13 +200,6 @@ void HandleDirectionChanged(ExpandDirection expandDirection)
 		}
 	}
 
-	void SetHeaderGestures(in IView header)
-	{
-		var headerView = (View)header;
-		headerView.GestureRecognizers.Remove(HeaderTapGestureRecognizer);
-		headerView.GestureRecognizers.Add(HeaderTapGestureRecognizer);
-	}
-
 	void OnHeaderTapGestureRecognizerTapped(object? sender, TappedEventArgs tappedEventArgs)
 	{
 		IsExpanded = !IsExpanded;
@@ -163,16 +208,11 @@ void OnHeaderTapGestureRecognizerTapped(object? sender, TappedEventArgs tappedEv
 
 	void ResizeExpanderInItemsView(TappedEventArgs tappedEventArgs)
 	{
-		if (Header is null)
-		{
-			return;
-		}
-
 		Element element = this;
 #if WINDOWS
 		var size = IsExpanded
 					? Measure(double.PositiveInfinity, double.PositiveInfinity)
-					: Header.Measure(double.PositiveInfinity, double.PositiveInfinity);
+					: headerContentView.Measure(double.PositiveInfinity, double.PositiveInfinity);
 #endif
 		while (element is not null)
 		{
@@ -201,6 +241,8 @@ void ResizeExpanderInItemsView(TappedEventArgs tappedEventArgs)
 
 	void IExpander.ExpandedChanged(bool isExpanded)
 	{
+		ContentHeight = isExpanded ? MaximumContentHeight : MinimumContentHeight;
+
 		if (Command?.CanExecute(CommandParameter) is true)
 		{
 			Command.Execute(CommandParameter);
@@ -208,4 +250,4 @@ void IExpander.ExpandedChanged(bool isExpanded)
 
 		tappedEventManager.HandleEvent(this, new ExpandedChangedEventArgs(isExpanded), nameof(ExpandedChanged));
 	}
-}
\ No newline at end of file
+}

From 78f40abd33d664e7d29edd5388dd2ecbd3ebce07 Mon Sep 17 00:00:00 2001
From: Stephen Quan <squan@esri.com>
Date: Fri, 4 Apr 2025 18:27:26 +1100
Subject: [PATCH 2/4] Introduce AnimationEnabled, ExpandEasing, ExpandDuration,
 CollapseEasing, CollapseDuration

---
 .../Pages/Views/Expander/ExpanderPage.xaml    |  15 +--
 .../Pages/Views/Expander/ExpanderPage.xaml.cs |  11 --
 .../Pages/Views/Expander/ExpanderPageCS.cs    |  14 +--
 .../Interfaces/IExpander.shared.cs            |  27 ++++-
 .../Views/Expander/Expander.shared.cs         | 111 +++++++++++++++---
 5 files changed, 125 insertions(+), 53 deletions(-)

diff --git a/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPage.xaml b/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPage.xaml
index b35365fd6e..15ddcb5973 100644
--- a/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPage.xaml
+++ b/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPage.xaml
@@ -17,7 +17,7 @@
 
             <Label Text="Simple expander" FontSize="24" FontAttributes="Bold"/>
 
-            <mct:Expander PropertyChanged="AnimateExpander">
+            <mct:Expander>
                 <mct:Expander.Header>
                     <Label Text="Simple Expander (Tap Me)" FontSize="16" FontAttributes="Bold"/>
                 </mct:Expander.Header>
@@ -32,12 +32,12 @@
 
             <Label Text="Multi-level expander" FontSize="24" FontAttributes="Bold"/>
 
-            <mct:Expander Direction="Up" PropertyChanged="AnimateExpander">
+            <mct:Expander Direction="Up">
                 <mct:Expander.Header>
                     <Label Text="Multi-Level Expander (Tap Me)" FontSize="16" FontAttributes="Bold"/>
                 </mct:Expander.Header>
                 <mct:Expander.Content>
-                    <mct:Expander Direction="Down" BackgroundColor="LightGray" PropertyChanged="AnimateExpander">
+                    <mct:Expander Direction="Down" BackgroundColor="LightGray">
                         <mct:Expander.Header>
                             <Label Text="Nested Expander (Tap Me)" FontSize="14" FontAttributes="Bold"/>
                         </mct:Expander.Header>
@@ -56,8 +56,7 @@
                     <DataTemplate>
                         <ViewCell>
                             <mct:Expander x:DataType="sample:ContentCreator"
-                                          ExpandedChanged="Expander_ExpandedChanged"
-                                          PropertyChanged="AnimateExpander">
+                                          ExpandedChanged="Expander_ExpandedChanged">
                                 <mct:Expander.Header>
                                     <Label Text="{Binding Name}"/>
                                 </mct:Expander.Header>
@@ -81,8 +80,7 @@
                 <CollectionView.ItemTemplate>
                     <DataTemplate>
                         <mct:Expander x:DataType="sample:ContentCreator"
-                                      ExpandedChanged="Expander_ExpandedChanged"
-                                      PropertyChanged="AnimateExpander">
+                                      ExpandedChanged="Expander_ExpandedChanged">
                             <mct:Expander.Header>
                                 <Label Text="{Binding Name}"/>
                             </mct:Expander.Header>
@@ -111,8 +109,7 @@
                 <CollectionView.ItemTemplate>
                     <DataTemplate>
                         <mct:Expander x:DataType="sample:ContentCreator"
-                                      ExpandedChanged="Expander_ExpandedChanged"
-                                      PropertyChanged="AnimateExpander">
+                                      ExpandedChanged="Expander_ExpandedChanged">
                             <mct:Expander.Header>
                                 <Label Text="{Binding Name}"/>
                             </mct:Expander.Header>
diff --git a/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPage.xaml.cs b/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPage.xaml.cs
index 1e86b4023c..c66102b8d7 100644
--- a/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPage.xaml.cs
+++ b/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPage.xaml.cs
@@ -16,7 +16,6 @@ public ExpanderPage(ExpanderViewModel viewModel) : base(viewModel)
 	async void Expander_ExpandedChanged(object sender, Core.ExpandedChangedEventArgs e)
 	{
 		var collapsedText = e.IsExpanded ? "expanded" : "collapsed";
-
 		await Toast.Make($"Expander is {collapsedText}").Show(CancellationToken.None);
 	}
 
@@ -24,14 +23,4 @@ async void GoToCSharpSampleClicked(object sender, EventArgs e)
 	{
 		await Navigation.PushAsync(new ExpanderPageCS());
 	}
-
-	async void AnimateExpander(object sender, System.ComponentModel.PropertyChangedEventArgs e)
-	{
-		if (e.PropertyName == CommunityToolkit.Maui.Views.Expander.IsExpandedProperty.PropertyName)
-		{
-			CommunityToolkit.Maui.Views.Expander expander = (CommunityToolkit.Maui.Views.Expander)sender;
-			expander.ContentHeight = expander.IsExpanded ? expander.MinimumContentHeight : expander.MaximumContentHeight;
-			await expander.ContentHeightTo(expander.IsExpanded ? expander.MaximumContentHeight : expander.MinimumContentHeight, 250, Easing.CubicInOut);
-		}
-	}
 }
diff --git a/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPageCS.cs b/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPageCS.cs
index 055d4999b7..1940e59c63 100644
--- a/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPageCS.cs
+++ b/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPageCS.cs
@@ -16,8 +16,6 @@ public ExpanderPageCS()
 
 		Title = "Expander Page, C# UI";
 
-		Expander expander;
-
 		Content = new VerticalStackLayout()
 		{
 			Spacing = 12,
@@ -33,7 +31,7 @@ public ExpanderPageCS()
 					.CenterHorizontal().TextCenter()
 					.Assign(out Picker picker),
 
-				(expander = new Expander
+				new Expander
 				{
 					Header = new Label()
 								.Text("Expander\n(Tap Me)")
@@ -62,17 +60,7 @@ public ExpanderPageCS()
 						static (Picker picker) => picker.SelectedIndex,
 						source: picker,
 						convert: (int selectedIndex) => Enum.IsDefined(typeof(ExpandDirection), selectedIndex) ? (ExpandDirection)selectedIndex : default)
-				 )
 			 }
 		};
-
-		expander.PropertyChanged += async (s, e) =>
-		{
-			if (e.PropertyName == Expander.IsExpandedProperty.PropertyName)
-			{
-				expander.ContentHeight = expander.IsExpanded ? expander.MinimumContentHeight : expander.MaximumContentHeight;
-				await expander.ContentHeightTo(expander.IsExpanded ? expander.MaximumContentHeight : expander.MinimumContentHeight, 250, Easing.CubicInOut);
-			}
-		};
 	}
 }
diff --git a/src/CommunityToolkit.Maui.Core/Interfaces/IExpander.shared.cs b/src/CommunityToolkit.Maui.Core/Interfaces/IExpander.shared.cs
index 8d05ed079a..5d04e5e23c 100644
--- a/src/CommunityToolkit.Maui.Core/Interfaces/IExpander.shared.cs
+++ b/src/CommunityToolkit.Maui.Core/Interfaces/IExpander.shared.cs
@@ -20,8 +20,33 @@ public interface IExpander : IContentView
 	/// </summary>
 	bool IsExpanded { get; set; }
 
+	/// <summary>
+	/// Gets or sets whether animations are enabled.
+	/// </summary>
+	bool AnimationsEnabled { get; set; }
+
+	/// <summary>
+	/// Gets or sets collapse animation easing.
+	/// </summary>
+	Easing? CollapseEasing { get; set; }
+
+	/// <summary>
+	/// Gets or sets collapse animation duration.
+	/// </summary>
+	uint CollapseDuration { get; set; }
+
+	/// <summary>
+	/// Gets or sets expand animation easing.
+	/// </summary>
+	Easing? ExpandEasing { get; set; }
+
+	/// <summary>
+	/// Gets or sets expand animation duration.
+	/// </summary>
+	uint ExpandDuration { get; set; }
+
 	/// <summary>
 	/// Action when <see cref="IsExpanded"/> changes
 	/// </summary>
 	void ExpandedChanged(bool isExpanded);
-}
\ No newline at end of file
+}
diff --git a/src/CommunityToolkit.Maui/Views/Expander/Expander.shared.cs b/src/CommunityToolkit.Maui/Views/Expander/Expander.shared.cs
index 0f01daa07d..7a9cc247f2 100644
--- a/src/CommunityToolkit.Maui/Views/Expander/Expander.shared.cs
+++ b/src/CommunityToolkit.Maui/Views/Expander/Expander.shared.cs
@@ -22,6 +22,36 @@ public partial class Expander : ContentView, IExpander
 	public static readonly BindableProperty DirectionProperty
 		= BindableProperty.Create(nameof(Direction), typeof(ExpandDirection), typeof(Expander), ExpandDirection.Down, propertyChanged: OnDirectionPropertyChanged);
 
+	/// <summary>
+	/// Backing BindableProperty for the <see cref="AnimationsEnabled"/> property.
+	/// </summary>
+	public static readonly BindableProperty AnimationsEnabledProperty
+		= BindableProperty.Create(nameof(AnimationsEnabledProperty), typeof(bool), typeof(Expander), true);
+
+	/// <summary>
+	/// Backing BindableProperty for the <see cref="CollapseDuration"/> property.
+	/// </summary>
+	public static readonly BindableProperty CollapseDurationProperty
+		= BindableProperty.Create(nameof(CollapseDuration), typeof(uint), typeof(Expander), (uint)250);
+
+	/// <summary>
+	/// Backing BindableProperty for the <see cref="CollapseEasing"/> property.
+	/// </summary>
+	public static readonly BindableProperty CollapseEasingProperty
+		= BindableProperty.Create(nameof(CollapseEasing), typeof(Easing), typeof(Expander));
+
+	/// <summary>
+	/// Backing BindableProperty for the <see cref="ExpandDuration"/> property.
+	/// </summary>
+	public static readonly BindableProperty ExpandDurationProperty
+		= BindableProperty.Create(nameof(ExpandDuration), typeof(uint), typeof(Expander), (uint)250);
+
+	/// <summary>
+	/// Backing BindableProperty for the <see cref="ExpandEasing"/> property.
+	/// </summary>
+	public static readonly BindableProperty ExpandEasingProperty
+		= BindableProperty.Create(nameof(ExpandEasing), typeof(Easing), typeof(Expander));
+
 	readonly WeakEventManager tappedEventManager = new();
 	readonly Grid contentGrid;
 	readonly ContentView headerContentView;
@@ -60,24 +90,12 @@ public Expander()
 		contentGrid.SetRow(bodyLayout, 1);
 
 		headerContentView.GestureRecognizers.Add(HeaderTapGestureRecognizer);
-
-		bodyContentView.PropertyChanged += (s, e) =>
-		{
-			if (e.PropertyName == nameof(ContentView.Height))
-			{
-				if (IsExpanded)
-				{
-					ContentHeight = bodyContentView.Height + 1;
-				}
-				OnPropertyChanged(nameof(MaximumContentHeight));
-			}
-		};
 	}
 
 	/// <summary>
 	/// Controls the visibility of the content inside the <see cref="Expander"/>.
 	/// </summary>
-	public double ContentHeight
+	double ContentHeight
 	{
 		get => bodyLayout.HeightRequest;
 		set
@@ -86,7 +104,6 @@ public double ContentHeight
 			if (bodyLayout.Height != newHeight)
 			{
 				bodyLayout.HeightRequest = newHeight;
-				OnPropertyChanged(nameof(ContentHeight));
 			}
 		}
 	}
@@ -94,12 +111,12 @@ public double ContentHeight
 	/// <summary>
 	/// The height of the content inside the <see cref="Expander"/> when it is collapsed.
 	/// </summary>
-	public double MinimumContentHeight => bodyLayout.MinimumHeightRequest;
+	double MinimumContentHeight => bodyLayout.MinimumHeightRequest;
 
 	/// <summary>
 	/// The height of the content inside the <see cref="Expander"/> when it is expanded.
 	/// </summary>
-	public double MaximumContentHeight => bodyContentView.Height + 1;
+	double MaximumContentHeight => bodyContentView.Height + 1;
 
 	/// <summary>
 	/// Animates the expanding or collapsing of the content inside the <see cref="Expander"/>.
@@ -108,7 +125,7 @@ public double ContentHeight
 	/// <param name="length">The time, in milliseconds, over which to animate the transition. The default is 250.</param>
 	/// <param name="easing">The easing function to use for the animation.</param>
 	/// <returns>A <see cref="Task"/> containing a <see cref="bool"/> value which indicates whether the animation was canceled. <see langword="true"/> indicates that the animation was canceled. <see langword="false"/> indicates that the animation ran to completion.</returns>
-	public Task<bool> ContentHeightTo(double value, uint length = 250, Easing? easing = null)
+	Task<bool> ContentHeightTo(double value, uint length = 250, Easing? easing = null)
 	{
 		if (easing == null)
 		{
@@ -155,6 +172,41 @@ public ExpandDirection Direction
 		}
 	}
 
+	/// <inheritdoc />
+	public bool AnimationsEnabled
+	{
+		get => (bool)GetValue(AnimationsEnabledProperty);
+		set => SetValue(AnimationsEnabledProperty, value);
+	}
+
+	/// <inheritdoc />
+	public uint CollapseDuration
+	{
+		get => (uint)GetValue(CollapseDurationProperty);
+		set => SetValue(CollapseDurationProperty, value);
+	}
+
+	/// <inheritdoc />
+	public Easing? CollapseEasing
+	{
+		get => (Easing?)GetValue(CollapseEasingProperty);
+		set => SetValue(CollapseEasingProperty, value);
+	}
+
+	/// <inheritdoc />
+	public uint ExpandDuration
+	{
+		get => (uint)GetValue(ExpandDurationProperty);
+		set => SetValue(ExpandDurationProperty, value);
+	}
+
+	/// <inheritdoc />
+	public Easing? ExpandEasing
+	{
+		get => (Easing?)GetValue(ExpandEasingProperty);
+		set => SetValue(ExpandEasingProperty, value);
+	}
+
 	static void OnContentPropertyChanged(BindableObject bindable, object oldValue, object newValue)
 	{
 		var expander = (Expander)bindable;
@@ -239,9 +291,30 @@ void ResizeExpanderInItemsView(TappedEventArgs tappedEventArgs)
 		}
 	}
 
-	void IExpander.ExpandedChanged(bool isExpanded)
+	async void IExpander.ExpandedChanged(bool isExpanded)
 	{
-		ContentHeight = isExpanded ? MaximumContentHeight : MinimumContentHeight;
+		if (isExpanded)
+		{
+			if (AnimationsEnabled)
+			{
+				await ContentHeightTo(MaximumContentHeight, ExpandDuration, ExpandEasing);
+			}
+			else
+			{
+				ContentHeight = MaximumContentHeight;
+			}
+		}
+		else
+		{
+			if (AnimationsEnabled)
+			{
+				await ContentHeightTo(MinimumContentHeight, CollapseDuration, CollapseEasing);
+			}
+			else
+			{
+				ContentHeight = MinimumContentHeight;
+			}
+		}
 
 		if (Command?.CanExecute(CommandParameter) is true)
 		{

From e12027f0310ed8e2b0fd124ac86f685cdbc37da8 Mon Sep 17 00:00:00 2001
From: Stephen Quan <squan@esri.com>
Date: Fri, 4 Apr 2025 18:36:23 +1100
Subject: [PATCH 3/4] Revert/minimize sample diff

---
 .../Pages/Views/Expander/ExpanderPage.xaml.cs                   | 2 +-
 .../Pages/Views/Expander/ExpanderPageCS.cs                      | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPage.xaml.cs b/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPage.xaml.cs
index c66102b8d7..9239102530 100644
--- a/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPage.xaml.cs
+++ b/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPage.xaml.cs
@@ -23,4 +23,4 @@ async void GoToCSharpSampleClicked(object sender, EventArgs e)
 	{
 		await Navigation.PushAsync(new ExpanderPageCS());
 	}
-}
+}
\ No newline at end of file
diff --git a/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPageCS.cs b/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPageCS.cs
index 1940e59c63..4725207cd2 100644
--- a/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPageCS.cs
+++ b/samples/CommunityToolkit.Maui.Sample/Pages/Views/Expander/ExpanderPageCS.cs
@@ -63,4 +63,4 @@ public ExpanderPageCS()
 			 }
 		};
 	}
-}
+}
\ No newline at end of file

From 7bb5f8beb9b08c330a29d2473202e66d511cf6cd Mon Sep 17 00:00:00 2001
From: Stephen Quan <squan@esri.com>
Date: Fri, 4 Apr 2025 22:33:32 +1100
Subject: [PATCH 4/4] Handle nested Expanders. Minor Expanders in
 CollectionView fixes.

---
 .../Views/Expander/Expander.shared.cs         | 50 ++++++++++++-------
 1 file changed, 31 insertions(+), 19 deletions(-)

diff --git a/src/CommunityToolkit.Maui/Views/Expander/Expander.shared.cs b/src/CommunityToolkit.Maui/Views/Expander/Expander.shared.cs
index 7a9cc247f2..ae136dab85 100644
--- a/src/CommunityToolkit.Maui/Views/Expander/Expander.shared.cs
+++ b/src/CommunityToolkit.Maui/Views/Expander/Expander.shared.cs
@@ -79,7 +79,6 @@ public Expander()
 				(bodyLayout = new VerticalStackLayout()
 				{
 					HeightRequest = 1,
-					MinimumHeightRequest = 1,
 					Padding = new Thickness(0, 1, 0, 0),
 					Children = { (bodyContentView = new ContentView()) }
 				})
@@ -89,35 +88,39 @@ public Expander()
 		contentGrid.SetRow(headerContentView, 0);
 		contentGrid.SetRow(bodyLayout, 1);
 
+		#region Special case for bubbling height from nested Expanders
+		bodyContentView.PropertyChanged += (s, e) =>
+		{
+			if (e.PropertyName == nameof(Height))
+			{
+				if (IsExpanded)
+				{
+					ContentHeight = bodyContentView.Height;
+				}
+			}
+		};
+		#endregion
+
 		headerContentView.GestureRecognizers.Add(HeaderTapGestureRecognizer);
 	}
 
 	/// <summary>
 	/// Controls the visibility of the content inside the <see cref="Expander"/>.
 	/// </summary>
-	double ContentHeight
+	public double ContentHeight
 	{
 		get => bodyLayout.HeightRequest;
 		set
 		{
-			double newHeight = Math.Max(Math.Min(value, MaximumContentHeight), MinimumContentHeight);
+			double newHeight = Math.Max(Math.Min(value, bodyContentView.Height + 1.0), 1.0);
 			if (bodyLayout.Height != newHeight)
 			{
 				bodyLayout.HeightRequest = newHeight;
 			}
+			OnPropertyChanged(nameof(ContentHeight));
 		}
 	}
 
-	/// <summary>
-	/// The height of the content inside the <see cref="Expander"/> when it is collapsed.
-	/// </summary>
-	double MinimumContentHeight => bodyLayout.MinimumHeightRequest;
-
-	/// <summary>
-	/// The height of the content inside the <see cref="Expander"/> when it is expanded.
-	/// </summary>
-	double MaximumContentHeight => bodyContentView.Height + 1;
-
 	/// <summary>
 	/// Animates the expanding or collapsing of the content inside the <see cref="Expander"/>.
 	/// </summary>
@@ -252,19 +255,28 @@ void HandleDirectionChanged(ExpandDirection expandDirection)
 		}
 	}
 
-	void OnHeaderTapGestureRecognizerTapped(object? sender, TappedEventArgs tappedEventArgs)
+	async void OnHeaderTapGestureRecognizerTapped(object? sender, TappedEventArgs tappedEventArgs)
 	{
 		IsExpanded = !IsExpanded;
+		if (AnimationsEnabled)
+		{
+			await Task.Delay(IsExpanded ? (int)ExpandDuration : (int)CollapseDuration);
+		}
 		HandleHeaderTapped?.Invoke(tappedEventArgs);
 	}
 
 	void ResizeExpanderInItemsView(TappedEventArgs tappedEventArgs)
 	{
+		if (Header is null)
+		{
+			return;
+		}
+
 		Element element = this;
 #if WINDOWS
 		var size = IsExpanded
 					? Measure(double.PositiveInfinity, double.PositiveInfinity)
-					: headerContentView.Measure(double.PositiveInfinity, double.PositiveInfinity);
+					: Header.Measure(double.PositiveInfinity, double.PositiveInfinity);
 #endif
 		while (element is not null)
 		{
@@ -297,22 +309,22 @@ async void IExpander.ExpandedChanged(bool isExpanded)
 		{
 			if (AnimationsEnabled)
 			{
-				await ContentHeightTo(MaximumContentHeight, ExpandDuration, ExpandEasing);
+				await ContentHeightTo(bodyContentView.Height + 1.0, ExpandDuration, ExpandEasing);
 			}
 			else
 			{
-				ContentHeight = MaximumContentHeight;
+				ContentHeight = bodyContentView.Height + 1.0;
 			}
 		}
 		else
 		{
 			if (AnimationsEnabled)
 			{
-				await ContentHeightTo(MinimumContentHeight, CollapseDuration, CollapseEasing);
+				await ContentHeightTo(1.0, CollapseDuration, CollapseEasing);
 			}
 			else
 			{
-				ContentHeight = MinimumContentHeight;
+				ContentHeight = 1.0;
 			}
 		}