Improve label mapping performance and ensure complete coverage including ToPlatform and subsequent property changes

src/Controls/src/Core/Entry/Entry.Mapper.cs

@@ -18,7 +18,7 @@ public partial class Entry
 			EntryHandler.Mapper.ReplaceMapping<Entry, IEntryHandler>(PlatformConfiguration.iOSSpecific.Entry.AdjustsFontSizeToFitWidthProperty.PropertyName, MapAdjustsFontSizeToFitWidth);
 #endif
 			EntryHandler.Mapper.ReplaceMapping<Entry, IEntryHandler>(nameof(Text), MapText);
-			EntryHandler.Mapper.ReplaceMapping<Entry, IEntryHandler>(nameof(TextTransform), MapText);
+			EntryHandler.Mapper.ReplaceMapping<Entry, IEntryHandler>(nameof(TextTransform), MapTextTransform);
 
 			// Material3 Entry Handler mappings
 #if ANDROID
@@ -42,5 +42,16 @@ public partial class Entry
 			EntryHandler.CommandMapper.PrependToMapping(nameof(IEntry.Focus), InputView.MapFocus);
 #endif
 		}
+
+		static void MapTextTransform(IEntryHandler handler, Entry entry)
+		{
+			if (entry.IsConnectingHandler())
+			{
+				// If we're connecting the handler, we don't want to map the text multiple times.
+				return;
+			}
+
+			MapText(handler, entry);
+		}
 	}
-}
+}

src/Controls/src/Core/Entry/Entry.iOS.cs

@@ -16,7 +16,14 @@ public static void MapAdjustsFontSizeToFitWidth(IEntryHandler handler, Entry ent
 		public static void MapText(IEntryHandler handler, Entry entry)
 		{
 			Platform.TextExtensions.UpdateText(handler.PlatformView, entry);
-			EntryHandler.MapFormatting(handler, entry);
+
+			if (!handler.IsConnectingHandler())
+			{
+				// If we're not connecting the handler, we need to update the text formatting
+				// This is because the text may have changed, and we need to ensure that
+				// any attributed string formatting is applied correctly.
+				EntryHandler.MapFormatting(handler, entry);
+			}
 		}
 
 		public static void MapCursorColor(EntryHandler handler, Entry entry) =>
@@ -28,4 +35,4 @@ public static void MapAdjustsFontSizeToFitWidth(EntryHandler handler, Entry entr
 		public static void MapText(EntryHandler handler, Entry entry) =>
 			MapText((IEntryHandler)handler, entry);
 	}
-}
+}

src/Controls/src/Core/Label/Label.Mapper.cs

@@ -61,7 +61,10 @@ static void MapTextTransform(ILabelHandler handler, Label label) =>
 		static void MapFormattedText(ILabelHandler handler, Label label)
 		{
 			if (label.IsConnectingHandler())
+			{
+				// If we're connecting the handler, we don't want to map the text multiple times.
 				return;
+			}
 
 			MapText(handler, label);
 		}
@@ -141,10 +144,10 @@ static void MapCharacterSpacing(ILabelHandler handler, Label label, Action<IElem
 
 		static void MapFont(ILabelHandler handler, Label label, Action<IElementHandler, IElement> baseMethod)
 		{
-			if (label.HasFormattedTextSpans)
+			// if there is formatted text,
+			// then we re-apply the whole formatted text
+			if (label.HasFormattedTextSpans && !handler.IsConnectingHandler())
 			{
-				// if there is formatted text,
-				// then we re-apply the whole formatted text
 				handler.UpdateValue(nameof(FormattedText));
 			}
 			else if (label.TextType == TextType.Text || !IsDefaultFont(label))
@@ -198,4 +201,4 @@ static bool IsDefaultFont(Label label)
 			return true;
 		}
 	}
-}
+}

src/Controls/src/Core/Label/Label.iOS.cs

@@ -1,5 +1,4 @@
 #nullable disable
-using System;
 using Microsoft.Maui.Controls.Platform;
 using Microsoft.Maui.Graphics;
 using UIKit;
@@ -23,7 +22,11 @@ public static void MapText(ILabelHandler handler, Label label)
 		{
 			Platform.LabelExtensions.UpdateText(handler.PlatformView, label);
 
-			MapFormatting(handler, label);
+			if (!handler.IsConnectingHandler())
+			{
+				// Any text update requires that we update any attributed string formatting
+				MapFormatting(handler, label);
+			}
 		}
 
 		public static void MapLineBreakMode(ILabelHandler handler, Label label)

src/Controls/src/Core/Platform/iOS/Extensions/FormattedStringExtensions.cs

@@ -32,15 +32,16 @@
 				label.LineBreakMode,
 				label.CharacterSpacing);
 
 		public static NSAttributedString ToNSAttributedString(
 			this FormattedString formattedString,
 			IFontManager fontManager,
 			double defaultLineHeight = -1,
 			TextAlignment defaultHorizontalAlignment = TextAlignment.Start,
 			Font? defaultFont = null,
 			Color? defaultColor = null,
-			TextTransform defaultTextTransform = TextTransform.Default)
-			=> formattedString.ToNSAttributedString(fontManager, defaultLineHeight, defaultHorizontalAlignment, defaultFont, defaultColor, defaultTextTransform, LineBreakMode.WordWrap, defaultCharacterSpacing: 0d);
+			TextTransform defaultTextTransform = TextTransform.Default,
+			LineBreakMode defaultLineBreakMode = LineBreakMode.WordWrap)
+			=> formattedString.ToNSAttributedString(fontManager, defaultLineHeight, defaultHorizontalAlignment, defaultFont, defaultColor, defaultTextTransform, defaultLineBreakMode, defaultCharacterSpacing: 0d);
 
 		internal static NSAttributedString ToNSAttributedString(
 			this FormattedString formattedString,
@@ -74,15 +75,16 @@
 			return attributed;
 		}
 
 		public static NSAttributedString ToNSAttributedString(
 			this Span span,
 			IFontManager fontManager,
 			double defaultLineHeight = -1,
 			TextAlignment defaultHorizontalAlignment = TextAlignment.Start,
 			Font? defaultFont = null,
 			Color? defaultColor = null,
-			TextTransform defaultTextTransform = TextTransform.Default)
-			=> span.ToNSAttributedString(fontManager, defaultLineHeight, defaultHorizontalAlignment, defaultFont, defaultColor, defaultTextTransform, LineBreakMode.WordWrap, defaultCharacterSpacing: 0d);
+			TextTransform defaultTextTransform = TextTransform.Default,
+			LineBreakMode defaultLineBreakMode = LineBreakMode.WordWrap)
+			=> span.ToNSAttributedString(fontManager, defaultLineHeight, defaultHorizontalAlignment, defaultFont, defaultColor, defaultTextTransform, defaultLineBreakMode, defaultCharacterSpacing: 0d);
 
 		internal static NSAttributedString ToNSAttributedString(
 			this Span span,
@@ -92,7 +94,7 @@
 			Font? defaultFont,
 			Color? defaultColor,
 			TextTransform defaultTextTransform,
-			LineBreakMode lineBreakMode,
+			LineBreakMode defaultLineBreakMode,
 			double defaultCharacterSpacing = 0d)
 		{
 			var defaultFontSize = defaultFont?.Size ?? fontManager.DefaultFontSize;
@@ -123,16 +125,27 @@
 				_ => UITextAlignment.Left
 			};
 
-			style.LineBreakMode = lineBreakMode switch
+			#if !MACOS
+			style.LineBreakMode = defaultLineBreakMode switch
 			{
 				LineBreakMode.NoWrap => UILineBreakMode.Clip,
-				LineBreakMode.WordWrap => UILineBreakMode.WordWrap,
 				LineBreakMode.CharacterWrap => UILineBreakMode.CharacterWrap,
 				LineBreakMode.HeadTruncation => UILineBreakMode.HeadTruncation,
-				LineBreakMode.TailTruncation => UILineBreakMode.TailTruncation,
 				LineBreakMode.MiddleTruncation => UILineBreakMode.MiddleTruncation,
+				LineBreakMode.TailTruncation => UILineBreakMode.TailTruncation,
 				_ => UILineBreakMode.WordWrap
 			};
+			#else
+			style.LineBreakMode = defaultLineBreakMode switch
+			{
+				LineBreakMode.NoWrap => NSLineBreakMode.Clipping,
+				LineBreakMode.CharacterWrap => NSLineBreakMode.CharWrapping,
+				LineBreakMode.HeadTruncation => NSLineBreakMode.TruncatingHead,
+				LineBreakMode.MiddleTruncation => NSLineBreakMode.TruncatingMiddle,
+				LineBreakMode.TailTruncation => NSLineBreakMode.TruncatingTail,
+				_ => NSLineBreakMode.ByWordWrapping
+			};
+			#endif
 
 			var font = span.GetEffectiveFont(defaultFontSize, defaultFont);
 			var hasUnderline = false;

src/Controls/tests/TestCases.HostApp/FeatureMatrix/Button/ButtonControlPage.xaml

@@ -55,7 +55,12 @@
               </Button>
 
               <Label Grid.Row="1"
-                     Text="Clicked Event: "/>
+                     Text="Clicked Event: "
+                     AutomationId="MainLabel">
+                     <Label.GestureRecognizers>
+                            <TapGestureRecognizer Tapped="MainLabel_Tapped"/>
+                     </Label.GestureRecognizers>
+              </Label>
               <Label Grid.Row="1"
                      Grid.Column="1"
                      x:Name="ClickedEventLabel"

src/Controls/tests/TestCases.HostApp/FeatureMatrix/Button/ButtonControlPage.xaml.cs

@@ -1,3 +1,5 @@
+using Microsoft.Maui.Controls.Internals;
+
 namespace Maui.Controls.Sample;
 
 public class ButtonControlPage : NavigationPage
@@ -52,4 +54,17 @@ public void OnButtonReleased(object sender, EventArgs e)
 			ReleasedEventLabel.Text = "Released Event Executed";
 		}
 	}
+
+	void MainLabel_Tapped(object sender, TappedEventArgs e)
+	{
+		// Recreate the page to verify initial mappers
+		ToolbarItems.Clear();
+		Content = new ContentView();
+		INameScope scope = this;
+		scope.UnregisterName("ClickedEventLabel");
+		scope.UnregisterName("ReleasedEventLabel");
+		scope.UnregisterName("PressedEventLabel");
+		scope.UnregisterName("ButtonShadow");
+		InitializeComponent();
+	}
 }

src/Controls/tests/TestCases.HostApp/FeatureMatrix/EntryControl/EntryControlPage.xaml

@@ -7,10 +7,14 @@
        <VerticalStackLayout Padding="20"
                             Spacing="8">
               <Label Text="Entry Control"
+                     AutomationId="MainLabel"
                      FontSize="20"
                      Margin="0,0,0,50"
-                     HorizontalOptions="Center"/>
-
+                     HorizontalOptions="Center">
+                     <Label.GestureRecognizers>
+                            <TapGestureRecognizer Tapped="MainLabel_Tapped"/>
+                     </Label.GestureRecognizers>
+              </Label>
               <local:UITestEntry x:Name="EntryControl"
                                  IsCursorVisible="False"
                                  Text="{Binding Text}"

src/Controls/tests/TestCases.HostApp/FeatureMatrix/EntryControl/EntryControlPage.xaml.cs

@@ -1,5 +1,6 @@
 using System.ComponentModel;
 using Microsoft.Maui.Controls;
+using Microsoft.Maui.Controls.Internals;
 
 namespace Maui.Controls.Sample;
 
@@ -130,4 +131,37 @@ private void EntryControl_Unfocused(object sender, FocusEventArgs e)
 			vm.UnfocusedText = eventInfo;
 		}
 	}
+
+	void MainLabel_Tapped(object sender, TappedEventArgs e)
+	{
+		// Recreate the page to verify initial mappers
+		ToolbarItems.Clear();
+		Content = new ContentView();
+		INameScope scope = this;
+		scope.UnregisterName("EntryControl");
+		scope.UnregisterName("TextChangedLabel");
+		scope.UnregisterName("SelectionLengthEntry");
+		scope.UnregisterName("CursorPositionEntry");
+		scope.UnregisterName("CompletedLabel");
+		scope.UnregisterName("FocusedLabel");
+		scope.UnregisterName("UnfocusedLabel");
+		scope.UnregisterName("grid");
+		InitializeComponent();
+
+		if (OperatingSystem.IsIOSVersionAtLeast(26))
+		{
+			grid.HeightRequest = 100;
+		}
+		else
+		{
+			grid.HeightRequest = 130;
+		}
+
+		// Reattach the PropertyChanged event handler after reinitialization
+		EntryControl.PropertyChanged += UpdateEntryControl;
+
+		// Update the entry fields to reflect current values
+		CursorPositionEntry.Text = EntryControl.CursorPosition.ToString();
+		SelectionLengthEntry.Text = EntryControl.SelectionLength.ToString();
+	}
 }

src/Controls/tests/TestCases.HostApp/FeatureMatrix/EntryControl/EntryOptionsPage.xaml

@@ -45,6 +45,7 @@
                                     Clicked="HorizontalAlignmentButton_Clicked"/>
                             <Button Text="End"
                                     AutomationId="HEnd"
+                                    FontSize="10"
                                     Clicked="HorizontalAlignmentButton_Clicked"/>
                      </HorizontalStackLayout>
                      <!-- Vertical Alignment -->

src/Controls/tests/TestCases.HostApp/FeatureMatrix/Label/LabelControlPage.xaml

@@ -5,31 +5,35 @@
              Title="LabelControlPage">
   <ContentPage.ToolbarItems>
     <ToolbarItem Text="Options"
-        Clicked="NavigateToOptionsPage_Clicked"
-        AutomationId="Options"/>
+                 Clicked="NavigateToOptionsPage_Clicked"
+                 AutomationId="Options"/>
   </ContentPage.ToolbarItems>
 
-    <VerticalStackLayout>
-      <Label
-        HeightRequest="600"
-        Text="{Binding Text , Mode=TwoWay}"
-        CharacterSpacing="{Binding CharacterSpacing}"
-        FontAttributes="{Binding FontAttributes}"
-        FontAutoScalingEnabled="{Binding FontAutoScalingEnabled}"
-        FontFamily="{Binding FontFamily}"
-        FontSize="{Binding FontSize}"
-        FormattedText="{Binding FormattedText}"
-        HorizontalTextAlignment="{Binding HorizontalTextAlignment}"
-        LineBreakMode="{Binding LineBreakMode}"
-        LineHeight="{Binding LineHeight}"
-        MaxLines="{Binding MaxLines}"
-        Padding="{Binding Padding}"
-        TextColor="{Binding TextColor}"
-        TextDecorations="{Binding TextDecorations}"
-        TextTransform="{Binding TextTransform}"
-        TextType="{Binding TextType}"
-        VerticalTextAlignment="{Binding VerticalTextAlignment}"
-        BackgroundColor="LightGray"
-        AutomationId="MainLabel"/>
-    </VerticalStackLayout>
+  <VerticalStackLayout>
+    <Label
+      HeightRequest="600"
+      Text="{Binding Text , Mode=TwoWay}"
+      CharacterSpacing="{Binding CharacterSpacing}"
+      FontAttributes="{Binding FontAttributes}"
+      FontAutoScalingEnabled="{Binding FontAutoScalingEnabled}"
+      FontFamily="{Binding FontFamily}"
+      FontSize="{Binding FontSize}"
+      FormattedText="{Binding FormattedText}"
+      HorizontalTextAlignment="{Binding HorizontalTextAlignment}"
+      LineBreakMode="{Binding LineBreakMode}"
+      LineHeight="{Binding LineHeight}"
+      MaxLines="{Binding MaxLines}"
+      Padding="{Binding Padding}"
+      TextColor="{Binding TextColor}"
+      TextDecorations="{Binding TextDecorations}"
+      TextTransform="{Binding TextTransform}"
+      TextType="{Binding TextType}"
+      VerticalTextAlignment="{Binding VerticalTextAlignment}"
+      BackgroundColor="LightGray"
+      AutomationId="MainLabel">
+      <Label.GestureRecognizers>
+        <TapGestureRecognizer Tapped="MainLabel_Tapped"/>
+      </Label.GestureRecognizers>
+    </Label>
+  </VerticalStackLayout>
 </ContentPage>

src/Controls/tests/TestCases.HostApp/FeatureMatrix/Label/LabelControlPage.xaml.cs

@@ -30,4 +30,16 @@ private async void NavigateToOptionsPage_Clicked(object sender, EventArgs e)
 		BindingContext = _viewModel = new LabelViewModel();
 		await Navigation.PushAsync(new LabelOptionsPage(_viewModel));
 	}
+
+	void MainLabel_Tapped(object sender, TappedEventArgs e)
+	{
+		// Recreate the page to verify initial mappers
+		// Clear BindingContext first so old Label properly detaches the FormattedString
+		// (triggers propertyChanging which unsubscribes events and calls RemoveSpans)
+		ToolbarItems.Clear();
+		BindingContext = null;
+		Content = new ContentView();
+		InitializeComponent();
+		BindingContext = _viewModel;
+	}
 }

src/Controls/tests/TestCases.HostApp/FeatureMatrix/Label/LabelOptionsPage.xaml

@@ -284,6 +284,13 @@
                                  CheckedChanged="OnLineBreakModeChanged"
                                  AutomationId="LineBreakModeTailTruncation"/>
                 </HorizontalStackLayout>
+                <HorizontalStackLayout>
+                    <Label Text="Single Line Formatted Text"
+                           VerticalOptions="Center"/>
+                    <CheckBox x:Name="SimpleFormattedTextCheckBox"
+                              CheckedChanged="SimpleFormattedTextCheckBox_CheckedChanged"
+                              AutomationId="SimpleFormattedText"/>
+                </HorizontalStackLayout>
             </VerticalStackLayout>
         </Grid>
     </VerticalStackLayout>

src/Controls/tests/TestCases.HostApp/FeatureMatrix/Label/LabelOptionsPage.xaml.cs

@@ -239,4 +239,15 @@ private void OnFormattedTextChanged(object sender, CheckedChangedEventArgs e)
 		}
 	}
 
+	private void SimpleFormattedTextCheckBox_CheckedChanged(object sender, CheckedChangedEventArgs e)
+	{
+		if (e.Value)
+		{
+			_viewModel.FormattedText = new FormattedString
+			{
+				Spans = { new Span { Text = "This is a Basic Label" } }
+			};
+			_viewModel.Text = null;
+		}
+	}
 }