feat(textbox): add support for text selection

src/Uno.UI.Runtime.Skia.Gtk/Input/GtkCorePointerInputSource.cs

@@ -486,7 +486,7 @@ private void UseDevice(PointerPoint pointer, Gdk.Device device)
 
 		var pointerPoint = new Windows.UI.Input.PointerPoint(
 			frameId: time,
-			timestamp: time,
+			timestamp: time * (ulong)TimeSpan.TicksPerMillisecond, // time is in ms, timestamp is in ticks
 			device: pointerDevice,
 			pointerId: pointerId,
 			rawPosition: rawPosition,

src/Uno.UI/Generated/3.0.0.0/Windows.UI.Xaml.Controls/TextBlock.cs

@@ -125,7 +125,7 @@ public double BaselineOffset
 			}
 		}
 #endif
-#if __ANDROID__ || __IOS__ || IS_UNIT_TESTS || __WASM__ || __SKIA__ || __NETSTD_REFERENCE__ || __MACOS__
+#if __ANDROID__ || __IOS__ || IS_UNIT_TESTS || __WASM__ || false || __NETSTD_REFERENCE__ || __MACOS__
 		[global::Uno.NotImplemented("__ANDROID__", "__IOS__", "IS_UNIT_TESTS", "__WASM__", "__SKIA__", "__NETSTD_REFERENCE__", "__MACOS__")]
 		public global::Windows.UI.Xaml.Media.SolidColorBrush SelectionHighlightColor
 		{
@@ -265,7 +265,7 @@ public bool IsTextTrimmed
 			typeof(global::Windows.UI.Xaml.Controls.TextBlock),
 			new Windows.UI.Xaml.FrameworkPropertyMetadata(default(global::Windows.UI.Xaml.OpticalMarginAlignment)));
 #endif
-#if __ANDROID__ || __IOS__ || IS_UNIT_TESTS || __WASM__ || __SKIA__ || __NETSTD_REFERENCE__ || __MACOS__
+#if __ANDROID__ || __IOS__ || IS_UNIT_TESTS || __WASM__ || false || __NETSTD_REFERENCE__ || __MACOS__
 		[global::Uno.NotImplemented("__ANDROID__", "__IOS__", "IS_UNIT_TESTS", "__WASM__", "__SKIA__", "__NETSTD_REFERENCE__", "__MACOS__")]
 		public static global::Windows.UI.Xaml.DependencyProperty SelectionHighlightColorProperty { get; } =
 		Windows.UI.Xaml.DependencyProperty.Register(

src/Uno.UI/UI/Xaml/Controls/TextBlock/TextBlock.Android.cs

@@ -67,6 +67,11 @@ static TextBlock()
 			}
 		}
 
+		public TextBlock()
+		{
+			_hyperlinks.CollectionChanged += HyperlinksOnCollectionChanged;
+		}
+
 		/// <summary>
 		/// Finds a private constructor that allows for the specification of MaxLines.
 		/// </summary>

src/Uno.UI/UI/Xaml/Controls/TextBlock/TextBlock.cs

@@ -46,6 +46,19 @@ public partial class TextBlock : DependencyObject
 
 		private Run _reusableRun;
 		private bool _skipInlinesChangedTextSetter;
+		private bool _subscribeToPointerEvents;
+		private bool _isPressed;
+		private (int start, int end) Selection
+		{
+			get => _selection;
+			set
+			{
+				_selection = value;
+#if __SKIA__
+				Inlines.Selection = (Math.Min(value.start, value.end), Math.Max(value.start, value.end));
+#endif
+			}
+		}
 
 #if !UNO_REFERENCE_API
 		public TextBlock()
@@ -93,6 +106,10 @@ public InlineCollection Inlines
 				{
 					_inlines = new InlineCollection(this);
 					UpdateInlines(Text);
+
+#if __SKIA__
+					SetupInlines();
+#endif
 				}
 
 				return _inlines;
@@ -251,6 +268,8 @@ protected virtual void OnTextChanged(string oldValue, string newValue)
 		{
 			UpdateInlines(newValue);
 
+			Selection = (0, 0);
+
 			OnTextChangedPartial();
 			InvalidateTextBlock();
 		}
@@ -474,10 +493,17 @@ public bool IsTextSelectionEnabled
 				typeof(TextBlock),
 				new FrameworkPropertyMetadata(
 					defaultValue: false,
-					propertyChangedCallback: (s, e) => ((TextBlock)s).OnIsTextSelectionEnabledChangedPartial()
+					propertyChangedCallback: (s, _) => ((TextBlock)s).OnIsTextSelectionEnabledChanged()
 				)
 			);
 
+		private void OnIsTextSelectionEnabledChanged()
+		{
+			Selection = (0, 0);
+
+			OnIsTextSelectionEnabledChangedPartial();
+		}
+
 		partial void OnIsTextSelectionEnabledChangedPartial();
 
 		#endregion
@@ -807,7 +833,7 @@ private void UpdateHyperlinks() { } // Events are subscribed in Hyperlink's ctor
 #else
 		private static readonly PointerEventHandler OnPointerPressed = (object sender, PointerRoutedEventArgs e) =>
 		{
-			if (sender is not TextBlock { HasHyperlink: true } that)
+			if (sender is not TextBlock that)
 			{
 				return;
 			}
@@ -818,26 +844,43 @@ private void UpdateHyperlinks() { } // Events are subscribed in Hyperlink's ctor
 				return;
 			}
 
-			var hyperlink = that.FindHyperlinkAt(point.Position);
-			if (hyperlink is null)
+			that._isPressed = true;
+			if (that.IsTextSelectionEnabled)
 			{
-				return;
+				var index = that.Inlines.GetIndexAt(point.Position, false);
+				that.Selection = (index, index);
 			}
 
-			if (!that.CapturePointer(e.Pointer))
+			if (that.FindHyperlinkAt(point.Position) is Hyperlink hyperlink)
 			{
-				return;
-			}
+				if (!that.CapturePointer(e.Pointer))
+				{
+					return;
+				}
 
-			hyperlink.SetPointerPressed(e.Pointer);
-			e.Handled = true;
-			that.CompleteGesture(); // Make sure to mute Tapped
+				hyperlink.SetPointerPressed(e.Pointer);
+				e.Handled = true;
+				that.CompleteGesture(); // Make sure to mute Tapped
+			}
 		};
 
 		private static readonly PointerEventHandler OnPointerReleased = (object sender, PointerRoutedEventArgs e) =>
 		{
-			if (sender is TextBlock that
-				&& that.IsCaptured(e.Pointer))
+			if (sender is not TextBlock that)
+			{
+				return;
+			}
+
+
+			if (that._isPressed && that.IsTextSelectionEnabled && that.FindHyperlinkAt(e.GetCurrentPoint(that).Position) is Hyperlink hyperlink)
+			{
+				// if we release on a hyperlink, we don't select anything
+				that.Selection = (0, 0);
+			}
+
+			that._isPressed = false;
+
+			if (that.IsCaptured(e.Pointer))
 			{
 				// On UWP we don't get the Tapped event, so make sure to abort it.
 				that.CompleteGesture();
@@ -869,7 +912,7 @@ private void UpdateHyperlinks() { } // Events are subscribed in Hyperlink's ctor
 
 		private static readonly PointerEventHandler OnPointerMoved = (sender, e) =>
 		{
-			if (sender is not TextBlock { HasHyperlink: true } that)
+			if (sender is not TextBlock that)
 			{
 				return;
 			}
@@ -883,6 +926,12 @@ private void UpdateHyperlinks() { } // Events are subscribed in Hyperlink's ctor
 				that._hyperlinkOver = hyperlink;
 				hyperlink?.SetPointerOver(e.Pointer);
 			}
+
+			if (that._isPressed && that.IsTextSelectionEnabled)
+			{
+				var index = that.Inlines.GetIndexAt(point.Position, false);
+				that.Selection = (that.Selection.start, index);
+			}
 		};
 
 		private static readonly PointerEventHandler OnPointerEntered = (sender, e) =>
@@ -932,8 +981,15 @@ private bool AbortHyperlinkCaptures(Pointer pointer)
 			return aborted;
 		}
 
-		private readonly List<(int start, int end, Hyperlink hyperlink)> _hyperlinks =
-			new List<(int start, int end, Hyperlink hyperlink)>();
+		private readonly ObservableCollection<(int start, int end, Hyperlink hyperlink)> _hyperlinks = new();
+		private (int start, int end) _selection;
+
+		private void HyperlinksOnCollectionChanged(object sender, NotifyCollectionChangedEventArgs e) => RecalculateSubscribeToPointerEvents();
+
+		private void RecalculateSubscribeToPointerEvents()
+		{
+			SubscribeToPointerEvents = HasHyperlink || IsTextSelectionEnabled;
+		}
 
 		private void UpdateHyperlinks()
 		{
@@ -943,13 +999,6 @@ private void UpdateHyperlinks()
 			{
 				if (HasHyperlink)
 				{
-					RemoveHandler(PointerPressedEvent, OnPointerPressed);
-					RemoveHandler(PointerReleasedEvent, OnPointerReleased);
-					RemoveHandler(PointerMovedEvent, OnPointerMoved);
-					RemoveHandler(PointerEnteredEvent, OnPointerEntered);
-					RemoveHandler(PointerExitedEvent, OnPointerExit);
-					RemoveHandler(PointerCaptureLostEvent, OnPointerCaptureLost);
-
 					// Make sure to clear the pressed state of removed hyperlinks
 					foreach (var hyperlink in _hyperlinks)
 					{
@@ -963,7 +1012,6 @@ private void UpdateHyperlinks()
 				return;
 			}
 
-			var previousHasHyperlinks = HasHyperlink;
 			var previousHyperLinks = _hyperlinks.Select(h => h.hyperlink).ToList();
 			_hyperlinkOver = null;
 			_hyperlinks.Clear();
@@ -990,27 +1038,6 @@ private void UpdateHyperlinks()
 			{
 				removed.AbortAllPointerState();
 			}
-
-			// Update events subscriptions if needed
-			// Note: we subscribe to those events only if needed as they increase marshaling on Android and WASM
-			if (HasHyperlink && !previousHasHyperlinks)
-			{
-				InsertHandler(PointerPressedEvent, OnPointerPressed);
-				InsertHandler(PointerReleasedEvent, OnPointerReleased);
-				InsertHandler(PointerMovedEvent, OnPointerMoved);
-				InsertHandler(PointerEnteredEvent, OnPointerEntered);
-				InsertHandler(PointerExitedEvent, OnPointerExit);
-				InsertHandler(PointerCaptureLostEvent, OnPointerCaptureLost);
-			}
-			else if (!HasHyperlink && previousHasHyperlinks)
-			{
-				RemoveHandler(PointerPressedEvent, OnPointerPressed);
-				RemoveHandler(PointerReleasedEvent, OnPointerReleased);
-				RemoveHandler(PointerMovedEvent, OnPointerMoved);
-				RemoveHandler(PointerEnteredEvent, OnPointerEntered);
-				RemoveHandler(PointerExitedEvent, OnPointerExit);
-				RemoveHandler(PointerCaptureLostEvent, OnPointerCaptureLost);
-			}
 		}
 
 		private bool HasHyperlink
@@ -1025,6 +1052,42 @@ private bool HasHyperlink
 			}
 		}
 
+		private bool SubscribeToPointerEvents
+		{
+			get => _subscribeToPointerEvents;
+			set
+			{
+				if (_subscribeToPointerEvents == value)
+				{
+					return;
+				}
+
+				_subscribeToPointerEvents = value;
+
+				// Update events subscriptions if needed
+				// Note: we subscribe to those events only if needed as they increase marshaling on Android and WASM
+				if (value)
+				{
+					InsertHandler(PointerPressedEvent, OnPointerPressed);
+					InsertHandler(PointerReleasedEvent, OnPointerReleased);
+					InsertHandler(PointerMovedEvent, OnPointerMoved);
+					InsertHandler(PointerEnteredEvent, OnPointerEntered);
+					InsertHandler(PointerExitedEvent, OnPointerExit);
+					InsertHandler(PointerCaptureLostEvent, OnPointerCaptureLost);
+				}
+				else
+				{
+					RemoveHandler(PointerPressedEvent, OnPointerPressed);
+					RemoveHandler(PointerReleasedEvent, OnPointerReleased);
+					RemoveHandler(PointerMovedEvent, OnPointerMoved);
+					RemoveHandler(PointerEnteredEvent, OnPointerEntered);
+					RemoveHandler(PointerExitedEvent, OnPointerExit);
+					RemoveHandler(PointerCaptureLostEvent, OnPointerCaptureLost);
+				}
+			}
+		}
+
+
 #if !__SKIA__
 		private Hyperlink FindHyperlinkAt(Point point)
 		{

src/Uno.UI/UI/Xaml/Controls/TextBlock/TextBlock.iOSmacOS.cs

@@ -21,5 +21,10 @@ private CGRect GetDrawRect(CGRect rect)
 
 			return rect;
 		}
+
+		public TextBlock()
+		{
+			_hyperlinks.CollectionChanged += HyperlinksOnCollectionChanged;
+		}
 	}
 }