[Entry] Enable support for text events

src/Compatibility/Core/src/Android/Renderers/EntryRenderer.cs

@@ -115,6 +115,7 @@ void ITextWatcher.BeforeTextChanged(ICharSequence s, int start, int count, int a
 		{
 		}
 
+		[PortHandler]
 		void ITextWatcher.OnTextChanged(ICharSequence s, int start, int before, int count)
 		{
 			Internals.TextTransformUtilites.SetPlainText(Element, s?.ToString());
@@ -524,6 +525,7 @@ protected virtual void UpdateIsReadOnly()
 			EditText.Focusable = isReadOnly;
 		}
 
+		[PortHandler("Ported Text setter")]
 		void UpdateText()
 		{
 			var text = Element.UpdateFormsText(Element.Text, Element.TextTransform);

src/Compatibility/Core/src/iOS/Renderers/EntryRenderer.cs

@@ -220,12 +220,14 @@ void OnEditingBegan(object sender, EventArgs e)
 			ElementController.SetValueFromRenderer(VisualElement.IsFocusedPropertyKey, true);
 		}
 
+		[PortHandler("Ported Text setter")]
 		void OnEditingChanged(object sender, EventArgs eventArgs)
 		{
 			ElementController.SetValueFromRenderer(Entry.TextProperty, Control.Text);
 			UpdateCursorFromControl(null);
 		}
 
+		[PortHandler("Ported Text setter")]
 		void OnEditingEnded(object sender, EventArgs e)
 		{
 			// Typing aid changes don't always raise EditingChanged event
@@ -361,6 +363,7 @@ protected virtual void UpdatePlaceholder()
 		protected virtual void UpdateAttributedPlaceholder(NSAttributedString nsAttributedString) =>
 			Control.AttributedPlaceholder = nsAttributedString;
 
+		[PortHandler]
 		void UpdateText()
 		{
 			var text = Element.UpdateFormsText(Element.Text, Element.TextTransform);

src/Controls/samples/Controls.Sample/Pages/MainPage.cs

@@ -50,7 +50,12 @@ void SetupMauiLayout()
 
 			verticalStack.Add(horizontalStack);
 
-			verticalStack.Add(new Entry());
+			var entry = new Entry();
+			entry.TextChanged += (sender, e) =>
+			{
+				System.Console.WriteLine($"Text Changed from '{e.OldTextValue}' to '{e.NewTextValue}'");
+			};
+			verticalStack.Add(entry);
 			verticalStack.Add(new Entry { Text = "Entry", TextColor = Color.DarkRed });
 			verticalStack.Add(new Entry { IsPassword = true, TextColor = Color.Black });
 			verticalStack.Add(new Entry { IsTextPredictionEnabled = false });

src/Core/src/Core/IEntry.cs

@@ -1,6 +1,6 @@
 namespace Microsoft.Maui
 {
-	public interface IEntry : IView, IText
+	public interface IEntry : IView, IText, ITextInput
 	{
 		bool IsPassword { get; }
 		bool IsTextPredictionEnabled { get; }

src/Core/src/Core/ITextInput.cs

@@ -1,14 +1,7 @@
-using Microsoft.Maui;
-
 namespace Microsoft.Maui
 {
 	public interface ITextInput : IText
 	{
-		Keyboard Keyboard { get; }
-		bool IsSpellCheckEnabled { get; }
-		int MaxLength { get; }
-		string Placeholder { get; }
-		Color PlaceholderColor { get; }
-		bool IsReadOnly { get; }
+		new string Text { get; set; }
 	}
 }

src/Core/src/Handlers/Entry/EntryHandler.Android.cs

@@ -1,17 +1,32 @@
 using Android.Content.Res;
+using Android.Text;
 using Android.Widget;
 
 namespace Microsoft.Maui.Handlers
 {
 	public partial class EntryHandler : AbstractViewHandler<IEntry, EditText>
 	{
+		TextWatcher Watcher { get; } = new TextWatcher();
+
 		static ColorStateList? DefaultTextColors { get; set; }
 
 		protected override EditText CreateNativeView()
 		{
 			return new EditText(Context);
 		}
 
+		protected override void ConnectHandler(EditText nativeView)
+		{
+			Watcher.Handler = this;
+			nativeView.AddTextChangedListener(Watcher);
+		}
+
+		protected override void DisconnectHandler(EditText nativeView)
+		{
+			nativeView.RemoveTextChangedListener(Watcher);
+			Watcher.Handler = null;
+		}
+
 		protected override void SetupDefaults(EditText nativeView)
 		{
 			base.SetupDefaults(nativeView);
@@ -37,5 +52,36 @@ public static void MapIsTextPredictionEnabled(EntryHandler handler, IEntry entry
 		{
 			handler.TypedNativeView?.UpdateIsTextPredictionEnabled(entry);
 		}
+
+		void OnTextChanged(string? text)
+		{
+			if (VirtualView == null || TypedNativeView == null)
+				return;
+
+			// Even though <null> is technically different to "", it has no
+			// functional difference to apps. Thus, hide it.
+			var mauiText = VirtualView.Text ?? string.Empty;
+			var nativeText = text ?? string.Empty;
+			if (mauiText != nativeText)
+				VirtualView.Text = nativeText;
+		}
+
+		class TextWatcher : Java.Lang.Object, ITextWatcher
+		{
+			public EntryHandler? Handler { get; set; }
+
+			void ITextWatcher.AfterTextChanged(IEditable? s)
+			{
+			}
+
+			void ITextWatcher.BeforeTextChanged(Java.Lang.ICharSequence? s, int start, int count, int after)
+			{
+			}
+
+			void ITextWatcher.OnTextChanged(Java.Lang.ICharSequence? s, int start, int before, int count)
+			{
+				Handler?.OnTextChanged(s?.ToString());
+			}
+		}
 	}
 }

src/Core/src/Handlers/Entry/EntryHandler.iOS.cs

@@ -1,24 +1,39 @@
-using CoreGraphics;
+using System;
+using Microsoft.Maui.Platform.iOS;
 using UIKit;
 
 namespace Microsoft.Maui.Handlers
 {
-	public partial class EntryHandler : AbstractViewHandler<IEntry, UITextField>
+	public partial class EntryHandler : AbstractViewHandler<IEntry, MauiTextField>
 	{
 		static readonly int BaseHeight = 30;
 
 		static UIColor? DefaultTextColor;
 
-		protected override UITextField CreateNativeView()
+		protected override MauiTextField CreateNativeView()
 		{
-			return new UITextField(CGRect.Empty)
+			return new MauiTextField
 			{
 				BorderStyle = UITextBorderStyle.RoundedRect,
 				ClipsToBounds = true
 			};
 		}
 
-		protected override void SetupDefaults(UITextField nativeView)
+		protected override void ConnectHandler(MauiTextField nativeView)
+		{
+			nativeView.EditingChanged += OnEditingChanged;
+			nativeView.EditingDidEnd += OnEditingEnded;
+			nativeView.TextPropertySet += OnTextPropertySet;
+		}
+
+		protected override void DisconnectHandler(MauiTextField nativeView)
+		{
+			nativeView.EditingChanged -= OnEditingChanged;
+			nativeView.EditingDidEnd -= OnEditingEnded;
+			nativeView.TextPropertySet -= OnTextPropertySet;
+		}
+
+		protected override void SetupDefaults(MauiTextField nativeView)
 		{
 			DefaultTextColor = nativeView.TextColor;
 		}
@@ -45,5 +60,24 @@ public static void MapIsTextPredictionEnabled(EntryHandler handler, IEntry entry
 		{
 			handler.TypedNativeView?.UpdateIsTextPredictionEnabled(entry);
 		}
+
+		void OnEditingChanged(object? sender, EventArgs e) => OnTextChanged();
+
+		void OnEditingEnded(object? sender, EventArgs e) => OnTextChanged();
+
+		void OnTextPropertySet(object? sender, EventArgs e) => OnTextChanged();
+
+		void OnTextChanged()
+		{
+			if (VirtualView == null || TypedNativeView == null)
+				return;
+
+			// Even though <null> is technically different to "", it has no
+			// functional difference to apps. Thus, hide it.
+			var mauiText = VirtualView.Text ?? string.Empty;
+			var nativeText = TypedNativeView.Text ?? string.Empty;
+			if (mauiText != nativeText)
+				VirtualView.Text = nativeText;
+		}
 	}
 }

src/Core/src/Platform/Android/EntryExtensions.cs

@@ -13,7 +13,11 @@ public static class EntryExtensions
 
 		public static void UpdateText(this EditText editText, IEntry entry)
 		{
-			editText.Text = entry.Text;
+			var newText = entry.Text ?? string.Empty;
+			var oldText = editText.Text ?? string.Empty;
+
+			if (oldText != newText)
+				editText.Text = newText;
 		}
 
 		public static void UpdateTextColor(this EditText editText, IEntry entry, ColorStateList? defaultColor)

src/Core/src/Platform/iOS/MauiTextField.cs

@@ -0,0 +1,30 @@
+using System;
+using CoreGraphics;
+using UIKit;
+
+namespace Microsoft.Maui.Platform.iOS
+{
+	public class MauiTextField : UITextField
+	{
+		public MauiTextField(CGRect frame)
+			: base(frame)
+		{
+		}
+
+		public MauiTextField()
+		{
+		}
+
+		public override string? Text
+		{
+			get => base.Text;
+			set
+			{
+				base.Text = value;
+				TextPropertySet?.Invoke(this,EventArgs.Empty);
+			}
+		}
+
+		public event EventHandler? TextPropertySet;
+	}
+}

src/Core/tests/DeviceTests/Handlers/Entry/EntryHandlerTests.Android.cs

@@ -13,6 +13,9 @@ EditText GetNativeEntry(EntryHandler entryHandler) =>
 		string GetNativeText(EntryHandler entryHandler) =>
 			GetNativeEntry(entryHandler).Text;
 
+		void SetNativeText(EntryHandler entryHandler, string text) =>
+			GetNativeEntry(entryHandler).Text = text;
+
 		Color GetNativeTextColor(EntryHandler entryHandler)
 		{
 			int currentTextColorInt = GetNativeEntry(entryHandler).CurrentTextColor;

src/Core/tests/DeviceTests/Handlers/Entry/EntryHandlerTests.cs

@@ -135,5 +135,49 @@ await ValidatePropertyUpdatesValue(
 				setValue,
 				unsetValue);
 		}
+
+		[Theory(DisplayName = "Text Changed Events Fire Correctly")]
+		// null/empty
+		[InlineData(null, null, false)]
+		[InlineData(null, "", false)]
+		[InlineData("", null, false)]
+		[InlineData("", "", false)]
+		// whitespace
+		[InlineData(null, " ", true)]
+		[InlineData("", " ", true)]
+		[InlineData(" ", null, true)]
+		[InlineData(" ", "", true)]
+		[InlineData(" ", " ", false)]
+		// text
+		[InlineData(null, "Hello", true)]
+		[InlineData("", "Hello", true)]
+		[InlineData(" ", "Hello", true)]
+		[InlineData("Hello", null, true)]
+		[InlineData("Hello", "", true)]
+		[InlineData("Hello", " ", true)]
+		[InlineData("Hello", "Goodbye", true)]
+		public async Task TextChangeEventsFireCorrectly(string initialText, string newText, bool eventExpected)
+		{
+			var entry = new EntryStub
+			{
+				Text = initialText,
+			};
+
+			var eventFiredCount = 0;
+			entry.TextChanged += (sender, e) =>
+			{
+				eventFiredCount++;
+
+				Assert.Equal(initialText, e.OldValue);
+				Assert.Equal(newText ?? string.Empty, e.NewValue);
+			};
+
+			await SetValueAsync(entry, newText, SetNativeText);
+
+			if (eventExpected)
+				Assert.Equal(1, eventFiredCount);
+			else
+				Assert.Equal(0, eventFiredCount);
+		}
 	}
 }

src/Core/tests/DeviceTests/Handlers/Entry/EntryHandlerTests.iOS.cs

@@ -11,6 +11,9 @@ UITextField GetNativeEntry(EntryHandler entryHandler) =>
 		string GetNativeText(EntryHandler entryHandler) =>
 			GetNativeEntry(entryHandler).Text;
 
+		void SetNativeText(EntryHandler entryHandler, string text) =>
+			GetNativeEntry(entryHandler).Text = text;
+
 		Color GetNativeTextColor(EntryHandler entryHandler) =>
 			GetNativeEntry(entryHandler).TextColor.ToColor();
 

src/Core/tests/DeviceTests/Handlers/HandlerTestBase.cs

@@ -47,6 +47,15 @@ protected Task<TValue> GetValueAsync<TValue>(IView view, Func<THandler, TValue>
 			});
 		}
 
+		protected Task SetValueAsync<TValue>(IView view, TValue value, Action<THandler, TValue> func)
+		{
+			return InvokeOnMainThreadAsync(() =>
+			{
+				var handler = CreateHandler(view);
+				func(handler, value);
+			});
+		}
+
 		async protected Task ValidatePropertyInitValue<TValue>(
 			IView view,
 			Func<TValue> GetValue,

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

@@ -1,15 +1,26 @@
-namespace Microsoft.Maui.DeviceTests.Stubs
+using System;
+
+namespace Microsoft.Maui.DeviceTests.Stubs
 {
 	public partial class EntryStub : StubBase, IEntry
 	{
 		private string _text;
 
-		public string Text { get => _text; set => this.SetProperty(ref _text, value); }
+		public string Text
+		{
+			get => _text;
+			set => SetProperty(ref _text, value, onChanged: OnTextChanged);
+		}
 
 		public Color TextColor { get; set; }
 
 		public bool IsPassword { get; set; }
 
 		public bool IsTextPredictionEnabled { get; set; }
+
+		public event EventHandler<StubPropertyChangedEventArgs<string>> TextChanged;
+
+		void OnTextChanged(string oldValue, string newValue) =>
+			TextChanged?.Invoke(this, new StubPropertyChangedEventArgs<string>(oldValue, newValue));
 	}
 }

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

@@ -36,14 +36,15 @@ public void Arrange(Rectangle bounds)
 
 		protected bool SetProperty<T>(ref T backingStore, T value,
 			[CallerMemberName] string propertyName = "",
-			Action onChanged = null)
+			Action<T, T> onChanged = null)
 		{
 			if (EqualityComparer<T>.Default.Equals(backingStore, value))
 				return false;
 
+			var oldValue = backingStore;
 			backingStore = value;
-			onChanged?.Invoke();
 			Handler?.UpdateValue(propertyName);
+			onChanged?.Invoke(oldValue, value);
 			return true;
 		}