[Android] picker - focus/unfocus events (#28122)

Author: kubaflo

src/Controls/tests/TestCases.HostApp/Issues/Issue28121.xaml

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             x:Class="Maui.Controls.Sample.Issues.Issue28121">
+    <VerticalStackLayout>
+        <Picker Focused="Picker_Focused"
+                Unfocused="Picker_Unfocused"
+                AutomationId="picker">
+            <Picker.ItemsSource>
+                <x:Array Type="{x:Type x:String}">
+                    <x:String>Item1</x:String>
+                    <x:String>Item2</x:String>
+                    <x:String>Item3</x:String>
+                </x:Array>
+            </Picker.ItemsSource>
+        </Picker>
+        <Label x:Name="FocusedLabel"
+               AutomationId="focusedLabel"
+               Text="Focused: false"/>
+        <Label x:Name="UnfocusedLabel"
+               AutomationId="unfocusedLabel"
+               Text="Unfocused: false"/>
+    </VerticalStackLayout>
+</ContentPage>

src/Controls/tests/TestCases.HostApp/Issues/Issue28121.xaml.cs

@@ -0,0 +1,21 @@
+namespace Maui.Controls.Sample.Issues;
+
+[Issue(IssueTracker.Github, 28121, "Picker Focused/Unfocused Events Do Not Fire", PlatformAffected.Android)]
+
+public partial class Issue28121 : ContentPage
+{
+	public Issue28121()
+	{
+		InitializeComponent();
+	}
+
+	void Picker_Focused(object sender, FocusEventArgs e)
+	{
+		FocusedLabel.Text = "Focused: true";
+	}
+
+	void Picker_Unfocused(object sender, FocusEventArgs e)
+	{
+		UnfocusedLabel.Text = "Unfocused: true";
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue28121.cs

@@ -0,0 +1,33 @@
+#if ANDROID
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+
+public class Issue28121 : _IssuesUITest
+{
+
+	public Issue28121(TestDevice testDevice) : base(testDevice)
+	{
+	}
+
+	public override string Issue => "Picker Focused/Unfocused Events Do Not Fire";
+
+	[Test]
+	[Category(UITestCategories.Entry)]
+	[Category(UITestCategories.Compatibility)]
+	public void FocusAndUnfocusEventsShouldFire()
+	{
+		App.WaitForElement("picker");
+		App.Tap("picker");
+		App.WaitForElement("Item1");
+		App.Click("Item1");
+		var focusedLabelText = App.FindElement("focusedLabel").GetText();
+		var unfocusedLabelText = App.FindElement("unfocusedLabel").GetText();
+
+		Assert.That(focusedLabelText, Is.EqualTo("Focused: true"));
+		Assert.That(unfocusedLabelText, Is.EqualTo("Unfocused: true"));
+	}
+}
+#endif

src/Core/src/Handlers/Picker/PickerHandler.Android.cs

@@ -152,10 +152,14 @@ void OnClick(object? sender, EventArgs e)
 
 				_dialog.SetCanceledOnTouchOutside(true);
 
-				_dialog.DismissEvent += (sender, args) =>
+				_dialog.DismissEvent += OnDismiss;
+
+				void OnDismiss(object? s, EventArgs e)
 				{
+					_dialog.DismissEvent -= OnDismiss;
+					PlatformView?.ClearFocus();
 					_dialog = null;
-				};
+				}
 
 				_dialog.Show();
 			}