Implement native events in WinUI SearchBarHandler (#875)

* Implement native events in WinUI SearchBarHandler

* Enable nullable in WinUI SearchBarHandler

Co-authored-by: Rui Marinho <me@ruimarinho.net>

src/Compatibility/Core/src/WinUI/SearchBarRenderer.cs

@@ -137,6 +137,7 @@ protected override void SetAutomationId(string id)
 			_queryTextBox.SetAutomationPropertiesAutomationId($"{id}_AutoSuggestBox");
 		}
 
+		[PortHandler]
 		void OnQuerySubmitted(AutoSuggestBox sender, AutoSuggestBoxQuerySubmittedEventArgs e)
 		{
 			// Modifies the text of the control if it does not match the query.
@@ -147,6 +148,7 @@ void OnQuerySubmitted(AutoSuggestBox sender, AutoSuggestBoxQuerySubmittedEventAr
 			Element.OnSearchButtonPressed();
 		}
 
+		[PortHandler]
 		void OnTextChanged(AutoSuggestBox sender, AutoSuggestBoxTextChangedEventArgs e)
 		{
 			if (e.Reason == AutoSuggestionBoxTextChangeReason.ProgrammaticChange)

src/Controls/src/Core/HandlerImpl/SearchBar.Impl.cs

@@ -7,5 +7,10 @@ public partial class SearchBar : ISearchBar
 		Font ITextStyle.Font => _font ??= Font.OfSize(FontFamily, FontSize).WithAttributes(FontAttributes);
 
 		bool ITextInput.IsTextPredictionEnabled => true;
+
+		void ISearchBar.SearchButtonPressed()
+		{
+			(this as ISearchBarController).OnSearchButtonPressed();
+		}
 	}
 }

src/Core/src/Core/ISearchBar.cs

@@ -5,6 +5,9 @@
 	/// </summary>
 	public interface ISearchBar : IView, ITextInput, ITextAlignment
 	{
-
+		/// <summary>
+		/// Notify when the user presses the Search button.
+		/// </summary>
+		void SearchButtonPressed();
 	}
 }

src/Core/src/Handlers/SearchBar/SearchBarHandler.Windows.cs

@@ -1,4 +1,5 @@
-using Microsoft.UI.Xaml.Controls;
+#nullable enable
+using Microsoft.UI.Xaml.Controls;
 
 namespace Microsoft.Maui.Handlers
 {
@@ -10,6 +11,18 @@ public partial class SearchBarHandler : ViewHandler<ISearchBar, AutoSuggestBox>
 			QueryIcon = new SymbolIcon(Symbol.Find)
 		};
 
+		protected override void ConnectHandler(AutoSuggestBox nativeView)
+		{
+			nativeView.QuerySubmitted += OnQuerySubmitted;
+			nativeView.TextChanged += OnTextChanged;
+		}
+
+		protected override void DisconnectHandler(AutoSuggestBox nativeView)
+		{
+			nativeView.QuerySubmitted -= OnQuerySubmitted;
+			nativeView.TextChanged -= OnTextChanged;
+		}
+
 		public static void MapText(SearchBarHandler handler, ISearchBar searchBar)
 		{
 			handler.NativeView?.UpdateText(searchBar);
@@ -42,5 +55,30 @@ public static void MapMaxLength(IViewHandler handler, ISearchBar searchBar) { }
 
 		[MissingMapper]
 		public static void MapIsReadOnly(IViewHandler handler, ISearchBar searchBar) { }
+
+		void OnQuerySubmitted(AutoSuggestBox? sender, AutoSuggestBoxQuerySubmittedEventArgs e)
+		{
+			if (VirtualView == null)
+				return;
+
+			// Modifies the text of the control if it does not match the query.
+			// This is possible because OnTextChanged is fired with a delay
+			if (e.QueryText != VirtualView.Text)
+				VirtualView.Text = e.QueryText;
+
+			VirtualView.SearchButtonPressed();
+		}
+
+		[PortHandler]
+		void OnTextChanged(AutoSuggestBox? sender, AutoSuggestBoxTextChangedEventArgs e)
+		{
+			if (e.Reason == AutoSuggestionBoxTextChangeReason.ProgrammaticChange)
+				return;
+
+			if (VirtualView == null || sender == null)
+				return;
+
+			VirtualView.Text = sender.Text;
+		}
 	}
 }

src/Core/tests/DeviceTests/Stubs/SearchBarStub.cs

@@ -25,5 +25,7 @@ public partial class SearchBarStub : StubBase, ISearchBar
 		public int MaxLength { get; set; }
 
 		public Keyboard Keyboard { get; set; }
+
+		public void SearchButtonPressed() { }
 	}
 }