[.NET 10] Add "Open/Close" API to picker controls (#29323)

* Initial changes

* More changes

* More changes

* More changes

* Implement DatePìcker IsOpen

* More changes

* Implemented on Picker

* Added DatePicker sample

* Added TimePicker sample

* Added Picker sample

* More changes

* More fixes

* More public API changes

* Updated sample

* Added UITest

* More changes

* More changes

* More tests

* More changes

* Pending comments

* Fixes in Stubs

* More changes

* Updated tests

* Implement IsOpen property on Windows TimePicker

* More changes to tests

* Adding Windows snapshots

* Fix the build

* Fix Android Picker issue not opening

* Added Android DatePicker dismiss listener

* Fix mistake

* Added dismiss listener to Android TimePicker

* Changes in the test

* Android snapshots

* More changes

* Changes in tests

* Updated sample adding specific date etc

* More snapshots

* Changes in the tests

* Updated test

* More changes in the test

* More Windows snapshots

* iOS snapshots

* Pending snapshots

* Added test orders

* More changes

* More changes

* Updated tests

* More changes

* More changes, fix test on Android

* Add check opening the Android TimePicker

* Changes based on PR feedback

* More PublicAPIs changes

* Fix issue dimissing the DatePicker

* More changes based on feedback

* More publicAPI fixes

* More publicAPI changes

* More fixes in publicAPIs

* Fixed test

* Complete merge

* Added default implementations

* More fixes

* More tests

* Fixed tests

* Updated tests

* Fixed tests on Windows

* Added more EventArgs for DatePicker and TimePicker opened and closed events

* More publicAPI changes

* More publicAPI changes

* - make internal

* - txt file updates

* Make MapIsOpen internal

* More changes in publicAPIs

---------

Co-authored-by: Shane Neuville <shneuvil@microsoft.com>

Author: jsuarezruiz

src/Controls/samples/Controls.Sample/Pages/Controls/DatePickerPage.xaml

@@ -97,6 +97,13 @@
                 Date="{x:Null}"/>
         <Button Text="Set to null" Clicked="SetDatePickerToNull" />
         <Button Text="Set to today" Clicked="SetDatePickerToToday" />
+      <Label      
+               Text="IsOpen"
+               Style="{StaticResource Headline}"/>
+      <DatePicker
+               x:Name="IsOpenDatePicker"/>
+      <Button Text="Open DatePicker" Clicked="OnOpenClicked" />
+      <Button Text="Close DatePicker" Clicked="OnCloseClicked" />
     </VerticalStackLayout>
     </views:BasePage.Content>               
 </views:BasePage>

src/Controls/samples/Controls.Sample/Pages/Controls/DatePickerPage.xaml.cs

@@ -14,6 +14,22 @@ public DatePickerPage()
 			UpdateDatePickerBackground();
 		}
 
+		protected override void OnAppearing()
+		{
+			base.OnAppearing();
+
+			IsOpenDatePicker.Opened += IsOpenDatePickerOpened;
+			IsOpenDatePicker.Closed += IsOpenDatePickerClosed;
+		}
+
+		protected override void OnDisappearing()
+		{
+			base.OnDisappearing();
+
+			IsOpenDatePicker.Opened -= IsOpenDatePickerOpened;
+			IsOpenDatePicker.Closed -= IsOpenDatePickerClosed;
+		}
+
 		void OnUpdateBackgroundButtonClicked(object sender, EventArgs e)
 		{
 			UpdateDatePickerBackground();
@@ -60,5 +76,25 @@ void SetDatePickerToToday(object sender, EventArgs e)
 		{
 			NullDatePicker.Date = DateTime.Now;
 		}
+
+		void OnOpenClicked(object sender, EventArgs e)
+		{
+			IsOpenDatePicker.IsOpen = true;
+		}
+
+		void OnCloseClicked(object sender, EventArgs e)
+		{
+			IsOpenDatePicker.IsOpen = false;
+		}
+
+		void IsOpenDatePickerOpened(object? sender, DatePickerOpenedEventArgs e)
+		{
+			Console.WriteLine("IsOpenDatePicker Opened");
+		}
+
+		void IsOpenDatePickerClosed(object? sender, DatePickerClosedEventArgs e)
+		{
+			Console.WriteLine("IsOpenDatePicker Closed");
+		}
 	}
 }

src/Controls/samples/Controls.Sample/Pages/Controls/PickerPage.xaml

@@ -114,6 +114,14 @@
                         </Picker.Items>
                     </Picker>
                 </Grid>
+                <Label      
+                    Text="IsOpen"
+                    Style="{StaticResource Headline}"/>
+                <Picker
+                    x:Name="IsOpenPicker"
+                    Title="Select an item" ItemsSource="{Binding PickerItems}" />
+                <Button Text="Open Picker" Clicked="OnOpenClicked" />
+                <Button Text="Close Picker" Clicked="OnCloseClicked" />
             </VerticalStackLayout>
         </ScrollView>
     </views:BasePage.Content>

src/Controls/samples/Controls.Sample/Pages/Controls/PickerPage.xaml.cs

@@ -30,6 +30,22 @@ public PickerPage()
 			};
 		}
 
+		protected override void OnAppearing()
+		{
+			base.OnAppearing();
+
+			IsOpenPicker.Opened += IsOpenPickerOpened;
+			IsOpenPicker.Closed += IsOpenPickerClosed;
+		}
+
+		protected override void OnDisappearing()
+		{
+			base.OnDisappearing();
+
+			IsOpenPicker.Opened -= IsOpenPickerOpened;
+			IsOpenPicker.Closed -= IsOpenPickerClosed;
+		}
+
 		void OnSelectedIndexChanged(object sender, EventArgs e)
 		{
 			string selectedCountry = (string)((Picker)sender).SelectedItem;
@@ -152,6 +168,26 @@ LayoutOptions GetLayoutOptions(int index)
 					return LayoutOptions.Fill;
 			}
 		}
+
+		void OnOpenClicked(object sender, EventArgs e)
+		{
+			IsOpenPicker.IsOpen = true;
+		}
+
+		void OnCloseClicked(object sender, EventArgs e)
+		{
+			IsOpenPicker.IsOpen = false;
+		}
+
+		void IsOpenPickerOpened(object? sender, PickerOpenedEventArgs e)
+		{
+			Console.WriteLine("IsOpenPicker Opened");
+		}
+
+		void IsOpenPickerClosed(object? sender, PickerClosedEventArgs e)
+		{
+			Console.WriteLine("IsOpenPicker Closed");
+		}
 	}
 
 	public class PickerData

src/Controls/samples/Controls.Sample/Pages/Controls/TimePickerPage.xaml

@@ -95,6 +95,13 @@
                 Time="{x:Null}"/>
             <Button Text="Set to null" Clicked="SetTimePickerToNull" />
             <Button Text="Set to now" Clicked="SetTimePickerToNow" />
+            <Label      
+                Text="IsOpen"
+                Style="{StaticResource Headline}"/>
+            <TimePicker
+                x:Name="IsOpenTimePicker"/>
+            <Button Text="Open TimePicker" Clicked="OnOpenClicked" />
+            <Button Text="Close TimePicker" Clicked="OnCloseClicked" />
     </VerticalStackLayout>
     </views:BasePage.Content>
 </views:BasePage>

src/Controls/samples/Controls.Sample/Pages/Controls/TimePickerPage.xaml.cs

@@ -13,6 +13,22 @@ public TimePickerPage()
 			UpdateTimePickerBackground();
 		}
 
+		protected override void OnAppearing()
+		{
+			base.OnAppearing();
+
+			IsOpenTimePicker.Opened += IsOpenTimePickerOpened;
+			IsOpenTimePicker.Closed += IsOpenTimePickerClosed;
+		}
+
+		protected override void OnDisappearing()
+		{
+			base.OnDisappearing();
+
+			IsOpenTimePicker.Opened -= IsOpenTimePickerOpened;
+			IsOpenTimePicker.Closed -= IsOpenTimePickerClosed;
+		}
+
 		void OnUpdateBackgroundButtonClicked(object sender, EventArgs e)
 		{
 			UpdateTimePickerBackground();
@@ -49,5 +65,25 @@ void SetTimePickerToNow(object sender, EventArgs e)
 		{
 			NullTimePicker.Time = DateTime.Now.TimeOfDay;
 		}
+
+		void OnOpenClicked(object sender, EventArgs e)
+		{
+			IsOpenTimePicker.IsOpen = true;
+		}
+
+		void OnCloseClicked(object sender, EventArgs e)
+		{
+			IsOpenTimePicker.IsOpen = false;
+		}
+
+		void IsOpenTimePickerOpened(object? sender, TimePickerOpenedEventArgs e)
+		{
+			Console.WriteLine("IsOpenTimePicker Opened");
+		}
+
+		void IsOpenTimePickerClosed(object? sender, TimePickerClosedEventArgs e)
+		{
+			Console.WriteLine("IsOpenTimePicker Closed");
+		}
 	}
 }

src/Controls/src/Core/DatePicker/DatePicker.cs

@@ -1,5 +1,6 @@
 #nullable disable
 using System;
+using System.Collections.Generic;
 using System.Diagnostics;
 using Microsoft.Maui.Controls.Internals;
 using Microsoft.Maui.Graphics;
@@ -45,6 +46,11 @@ public partial class DatePicker : View, IFontElement, ITextElement, IElementConf
 		/// <summary>Bindable property for <see cref="FontAutoScalingEnabled"/>.</summary>
 		public static readonly BindableProperty FontAutoScalingEnabledProperty = FontElement.FontAutoScalingEnabledProperty;
 
+		/// <summary>Bindable property for <see cref="IsOpen"/>.</summary>
+		public static readonly BindableProperty IsOpenProperty =	
+			BindableProperty.Create(nameof(IDatePicker.IsOpen), typeof(bool), typeof(DatePicker), default, BindingMode.TwoWay,
+				propertyChanged: OnIsOpenPropertyChanged);
+
 		readonly Lazy<PlatformConfigurationRegistry<DatePicker>> _platformConfigurationRegistry;
 
 		/// <include file="../../docs/Microsoft.Maui.Controls/DatePicker.xml" path="//Member[@MemberName='.ctor']/Docs/*" />
@@ -132,7 +138,18 @@ public bool FontAutoScalingEnabled
 			get => (bool)GetValue(FontAutoScalingEnabledProperty);
 			set => SetValue(FontAutoScalingEnabledProperty, value);
 		}
-
+		
+		public bool IsOpen
+		{
+			get => (bool)GetValue(IsOpenProperty);
+			set => SetValue(IsOpenProperty, value);
+		}
+		
+		static void OnIsOpenPropertyChanged(BindableObject bindable, object oldValue, object newValue)
+		{
+			((DatePicker)bindable).OnIsOpenPropertyChanged((bool)oldValue, (bool)newValue);
+		}
+		
 		void IFontElement.OnFontFamilyChanged(string oldValue, string newValue) =>
 			HandleFontChanged();
 
@@ -158,11 +175,50 @@ void ITextElement.OnTextTransformChanged(TextTransform oldValue, TextTransform n
 		{
 		}
 
+		readonly Queue<Action> _pendingIsOpenActions = new Queue<Action>();
+		
+		void OnIsOpenPropertyChanged(bool oldValue, bool newValue)
+		{
+			if (Handler?.VirtualView is DatePicker)
+			{
+				HandleIsOpenChanged();
+			}
+			else
+			{
+				_pendingIsOpenActions.Enqueue(HandleIsOpenChanged);
+			}
+		}
+		
+		protected override void OnHandlerChanged()
+		{
+			base.OnHandlerChanged();
+            
+			// Process any pending actions when handler becomes available
+			while (_pendingIsOpenActions.Count > 0 && Handler != null)
+			{
+				var action = _pendingIsOpenActions.Dequeue();
+				action.Invoke();
+			}
+		}
+		
+		void HandleIsOpenChanged()
+		{
+			if (Handler?.VirtualView is not DatePicker datePicker)
+				return;
+
+			if (datePicker.IsOpen)
+				datePicker.Opened?.Invoke(datePicker, DatePickerOpenedEventArgs.Empty);
+			else
+				datePicker.Closed?.Invoke(datePicker, DatePickerClosedEventArgs.Empty);
+		}
+
 		/// <include file="../../docs/Microsoft.Maui.Controls/DatePicker.xml" path="//Member[@MemberName='UpdateFormsText']/Docs/*" />
 		public virtual string UpdateFormsText(string source, TextTransform textTransform)
 			=> TextTransformUtilities.GetTransformedText(source, textTransform);
 
 		public event EventHandler<DateChangedEventArgs> DateSelected;
+		public event EventHandler<DatePickerOpenedEventArgs> Opened;
+		public event EventHandler<DatePickerClosedEventArgs> Closed;
 
 		static object CoerceDate(BindableObject bindable, object value)
 		{

src/Controls/src/Core/DatePickerClosedEventArgs.cs

@@ -0,0 +1,17 @@
+using System;
+
+namespace Microsoft.Maui.Controls;
+
+/// <summary>
+/// Provides event data for the event that is raised when a DatePicker control is closed.
+/// </summary>
+public class DatePickerClosedEventArgs : EventArgs
+{
+	/// <summary>
+	/// Gets a reusable empty instance of DatePickerClosedEventArgs.
+	/// </summary>
+	/// <value>
+	/// A static readonly instance of DatePickerClosedEventArgs that can be reused to avoid unnecessary object allocation.
+	/// </value>
+	internal new static readonly DatePickerClosedEventArgs Empty = new();
+}

src/Controls/src/Core/DatePickerOpenedEventArgs.cs

@@ -0,0 +1,17 @@
+using System;
+
+namespace Microsoft.Maui.Controls;
+
+/// <summary>
+/// Provides event data for the event that is raised when a DatePicker control is opened.
+/// </summary>
+public class DatePickerOpenedEventArgs : EventArgs
+{
+	/// <summary>
+	/// Gets a reusable empty instance of DatePickerOpenedEventArgs.
+	/// </summary>
+	/// <value>
+	/// A static readonly instance of DatePickerOpenedEventArgs that can be reused to avoid unnecessary object allocation.
+	/// </value>
+	internal new static readonly DatePickerOpenedEventArgs Empty = new();
+}

src/Controls/src/Core/Picker/Picker.cs

@@ -65,6 +65,11 @@ public partial class Picker : View, IFontElement, ITextElement, ITextAlignmentEl
 		/// <summary>Bindable property for <see cref="VerticalTextAlignment"/>.</summary>
 		public static readonly BindableProperty VerticalTextAlignmentProperty = TextAlignmentElement.VerticalTextAlignmentProperty;
 
+		/// <summary>Bindable property for <see cref="IsOpen"/>.</summary>
+		public static readonly BindableProperty IsOpenProperty =	
+			BindableProperty.Create(nameof(IPicker.IsOpen), typeof(bool), typeof(Picker), default, BindingMode.TwoWay,
+				propertyChanged: OnIsOpenPropertyChanged);
+
 		readonly Lazy<PlatformConfigurationRegistry<Picker>> _platformConfigurationRegistry;
 
 		/// <include file="../../docs/Microsoft.Maui.Controls/Picker.xml" path="//Member[@MemberName='.ctor']/Docs/*" />
@@ -220,7 +225,20 @@ public BindingBase ItemDisplayBinding
 			}
 		}
 
+		public bool IsOpen
+		{
+			get => (bool)GetValue(IsOpenProperty);
+			set => SetValue(IsOpenProperty, value);
+		}
+
+		static void OnIsOpenPropertyChanged(BindableObject bindable, object oldValue, object newValue)
+		{
+			((Picker)bindable).OnIsOpenPropertyChanged((bool)oldValue, (bool)newValue);
+		}
+		
 		public event EventHandler SelectedIndexChanged;
+		public event EventHandler<PickerOpenedEventArgs> Opened;
+		public event EventHandler<PickerClosedEventArgs> Closed;
 
 		static readonly BindableProperty s_displayProperty =
 			BindableProperty.Create("Display", typeof(string), typeof(Picker), default(string));
@@ -287,6 +305,43 @@ void OnItemsSourceChanged(IList oldValue, IList newValue)
 			}
 		}
 
+		readonly Queue<Action> _pendingIsOpenActions = new Queue<Action>();
+		
+		void OnIsOpenPropertyChanged(bool oldValue, bool newValue)
+		{
+			if (Handler?.VirtualView is Picker)
+			{
+				HandleIsOpenChanged();
+			}
+			else
+			{
+				_pendingIsOpenActions.Enqueue(HandleIsOpenChanged);
+			}
+		}
+		
+		protected override void OnHandlerChanged()
+		{
+			base.OnHandlerChanged();
+            
+			// Process any pending actions when handler becomes available
+			while (_pendingIsOpenActions.Count > 0 && Handler != null)
+			{
+				var action = _pendingIsOpenActions.Dequeue();
+				action.Invoke();
+			}
+		}
+		
+		void HandleIsOpenChanged()
+		{
+			if (Handler?.VirtualView is not Picker picker)
+				return;
+
+			if (picker.IsOpen)
+				picker.Opened?.Invoke(picker, PickerOpenedEventArgs.Empty);
+			else
+				picker.Closed?.Invoke(picker, PickerClosedEventArgs.Empty);
+		}
+
 		void CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
 		{
 			switch (e.Action)