Implement LineBreakMode property in LabelHandlers (#458)

src/Compatibility/Core/src/Android/Extensions/TextViewExtensions.cs

@@ -32,7 +32,7 @@ public static void SetLineBreakMode(this TextView textView, Label label)
 		public static void SetLineBreakMode(this TextView textView, Button button) =>
 			SetLineBreak(textView, button.LineBreakMode);
 
-
+		[PortHandler]
 		public static int SetLineBreak(TextView textView, LineBreakMode lineBreakMode)
 		{
 			int maxLines = Int32.MaxValue;

src/Compatibility/Core/src/Android/FastRenderers/LabelRenderer.cs

@@ -365,6 +365,7 @@ void UpdateCharacterSpacing()
 			}
 		}
 
+		[PortHandler]
 		void UpdateLineBreakMode()
 		{
 			this.SetLineBreakMode(Element);

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

@@ -354,6 +354,7 @@ void UpdateHorizontalTextAlignment()
 #endif
 		}
 
+		[PortHandler]
 		void UpdateLineBreakMode()
 		{
 #if __MOBILE__

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

@@ -5,7 +5,6 @@
 
 namespace Maui.Controls.Sample.Pages
 {
-
 	public class MainPage : ContentPage, IPage
 	{
 		MainPageViewModel _viewModel;
@@ -24,6 +23,15 @@ public MainPage(MainPageViewModel viewModel)
 
 		void SetupMauiLayout()
 		{
+			const string loremIpsum =
+				"Lorem ipsum dolor sit amet, consectetur adipiscing elit. " +
+				"Quisque ut dolor metus. Duis vel iaculis mauris, sit amet finibus mi. " +
+				"Etiam congue ornare risus, in facilisis libero tempor eget. " +
+				"Phasellus mattis mollis libero ut semper. In sit amet sapien odio. " +
+				"Sed interdum ullamcorper dui eu rutrum. Vestibulum non sagittis justo. " +
+				"Cras rutrum scelerisque elit, et porta est lobortis ac. " +
+				"Pellentesque eu ornare tortor. Sed bibendum a nisl at laoreet.";
+
 			var verticalStack = new VerticalStackLayout() { Spacing = 5, BackgroundColor = Color.AntiqueWhite };
 			var horizontalStack = new HorizontalStackLayout() { Spacing = 2, BackgroundColor = Color.CornflowerBlue };
 
@@ -35,6 +43,10 @@ void SetupMauiLayout()
 			verticalStack.Add(new Label { Text = "This should be BOLD text!", FontAttributes = FontAttributes.Bold });
 			verticalStack.Add(new Label { Text = "This should be a CUSTOM font!", FontFamily = "Dokdo" });
 			verticalStack.Add(new Label { Text = "This should have padding", Padding = new Thickness(40), BackgroundColor = Color.LightBlue });
+			verticalStack.Add(new Label { Text = loremIpsum });
+			verticalStack.Add(new Label { Text = loremIpsum, MaxLines = 2 });
+			verticalStack.Add(new Label { Text = loremIpsum, LineBreakMode = LineBreakMode.TailTruncation });
+			verticalStack.Add(new Label { Text = loremIpsum, MaxLines = 2, LineBreakMode = LineBreakMode.TailTruncation });
 
 			var underlineLabel = new Label { Text = "underline", TextDecorations = TextDecorations.Underline };
 			verticalStack.Add(underlineLabel);

src/Core/src/Core/ILabel.cs

@@ -5,6 +5,11 @@ namespace Microsoft.Maui
 	/// </summary>
 	public interface ILabel : IView, IText
 	{
+		/// <summary>
+		/// Gets the option for line breaking.
+		/// </summary>
+		LineBreakMode LineBreakMode { get; }
+
 		/// <summary>
 		/// Gets the maximum number of lines allowed in the Label.
 		/// </summary>

src/Core/src/Handlers/Label/LabelHandler.Android.cs

@@ -37,6 +37,11 @@ public static void MapCharacterSpacing(LabelHandler handler, ILabel label)
 			handler.TypedNativeView?.UpdateCharacterSpacing(label);
 		}
 
+		public static void MapLineBreakMode(LabelHandler handler, ILabel label)
+		{
+			handler.TypedNativeView?.UpdateLineBreakMode(label);
+		}
+
 		public static void MapMaxLines(LabelHandler handler, ILabel label)
 		{
 			handler.TypedNativeView?.UpdateMaxLines(label);

src/Core/src/Handlers/Label/LabelHandler.Standard.cs

@@ -10,6 +10,7 @@ public static void MapText(IViewHandler handler, ILabel label) { }
 		public static void MapTextColor(IViewHandler handler, ILabel label) { }
 		public static void MapCharacterSpacing(IViewHandler handler, ILabel label) { }
 		public static void MapFont(LabelHandler handler, ILabel label) { }
+		public static void MapLineBreakMode(LabelHandler handler, ILabel label) { }
 		public static void MapTextDecorations(LabelHandler handler, ILabel label) { }
 		public static void MapMaxLines(IViewHandler handler, ILabel label) { }
 		public static void MapPadding(LabelHandler handler, ILabel label) {	}

src/Core/src/Handlers/Label/LabelHandler.cs

@@ -9,6 +9,7 @@ public partial class LabelHandler
 			[nameof(ILabel.CharacterSpacing)] = MapCharacterSpacing,
 			[nameof(ILabel.MaxLines)] = MapMaxLines,
 			[nameof(ILabel.Font)] = MapFont,
+			[nameof(ILabel.LineBreakMode)] = MapLineBreakMode,
 			[nameof(ILabel.Padding)] = MapPadding,
 			[nameof(ILabel.TextDecorations)] = MapTextDecorations
 		};

src/Core/src/Handlers/Label/LabelHandler.iOS.cs

@@ -23,6 +23,11 @@ public static void MapCharacterSpacing(LabelHandler handler, ILabel label)
 			handler.TypedNativeView?.UpdateCharacterSpacing(label);
 		}
 
+		public static void MapLineBreakMode(LabelHandler handler, ILabel label)
+		{
+			handler.TypedNativeView?.UpdateLineBreakMode(label);
+		}
+
 		public static void MapMaxLines(LabelHandler handler, ILabel label)
 		{
 			handler.TypedNativeView?.UpdateMaxLines(label);

src/Core/src/Platform/Android/LabelExtensions.cs

@@ -1,4 +1,5 @@
 using Android.Graphics;
+using Android.Text;
 using Android.Util;
 using Android.Widget;
 
@@ -39,6 +40,11 @@ public static void UpdateFont(this TextView textView, ILabel label, IFontManager
 			textView.SetTextSize(ComplexUnitType.Sp, sp);
 		}
 
+		public static void UpdateLineBreakMode(this TextView textView, ILabel label)
+		{
+			textView.SetLineBreakMode(label);
+		}
+
 		public static void UpdateMaxLines(this TextView textView, ILabel label)
 		{
 			int maxLinex = label.MaxLines;
@@ -76,5 +82,47 @@ public static void UpdateTextDecorations(this TextView textView, ILabel label)
 			else
 				textView.PaintFlags |= PaintFlags.UnderlineText;
 		}
+
+		internal static void SetLineBreakMode(this TextView textView, ILabel label)
+		{
+			var lineBreakMode = label.LineBreakMode;
+
+			int maxLines = label.MaxLines;
+			if (maxLines <= 0)
+				maxLines = int.MaxValue;
+
+			bool singleLine = false;
+
+			switch (lineBreakMode)
+			{
+				case LineBreakMode.NoWrap:
+					maxLines = 1;
+					textView.Ellipsize = null;
+					break;
+				case LineBreakMode.WordWrap:
+					textView.Ellipsize = null;
+					break;
+				case LineBreakMode.CharacterWrap:
+					textView.Ellipsize = null;
+					break;
+				case LineBreakMode.HeadTruncation:
+					maxLines = 1;
+					singleLine = true; // Workaround for bug in older Android API versions (https://bugzilla.xamarin.com/show_bug.cgi?id=49069)
+					textView.Ellipsize = TextUtils.TruncateAt.Start;
+					break;
+				case LineBreakMode.TailTruncation:
+					maxLines = 1;
+					textView.Ellipsize = TextUtils.TruncateAt.End;
+					break;
+				case LineBreakMode.MiddleTruncation:
+					maxLines = 1;
+					singleLine = true; // Workaround for bug in older Android API versions (https://bugzilla.xamarin.com/show_bug.cgi?id=49069)
+					textView.Ellipsize = TextUtils.TruncateAt.Middle;
+					break;
+			}
+
+			textView.SetSingleLine(singleLine);
+			textView.SetMaxLines(maxLines);
+		}
 	}
 }

src/Core/src/Platform/iOS/LabelExtensions.cs

@@ -47,6 +47,11 @@ public static void UpdateFont(this UILabel nativeLabel, ILabel label, IFontManag
 			nativeLabel.UpdateCharacterSpacing(label);
 		}
 
+		public static void UpdateLineBreakMode(this UILabel nativeLabel, ILabel label)
+		{
+			SetLineBreakMode(nativeLabel, label);
+		}
+
 		public static void UpdateMaxLines(this UILabel nativeLabel, ILabel label)
 		{
 			int maxLines = label.MaxLines;
@@ -66,6 +71,41 @@ public static void UpdatePadding(this MauiLabel nativeLabel, ILabel label)
 				(float)label.Padding.Right);
 		}
 
+		internal static void SetLineBreakMode(this UILabel nativeLabel, ILabel label)
+		{
+			int maxLines = label.MaxLines;
+			if (maxLines < 0)
+				maxLines = 0;
+
+			switch (label.LineBreakMode)
+			{
+				case LineBreakMode.NoWrap:
+					nativeLabel.LineBreakMode = UILineBreakMode.Clip;
+					maxLines = 1;
+					break;
+				case LineBreakMode.WordWrap:
+					nativeLabel.LineBreakMode = UILineBreakMode.WordWrap;
+					break;
+				case LineBreakMode.CharacterWrap:
+					nativeLabel.LineBreakMode = UILineBreakMode.CharacterWrap;
+					break;
+				case LineBreakMode.HeadTruncation:
+					nativeLabel.LineBreakMode = UILineBreakMode.HeadTruncation;
+					maxLines = 1;
+					break;
+				case LineBreakMode.MiddleTruncation:
+					nativeLabel.LineBreakMode = UILineBreakMode.MiddleTruncation;
+					maxLines = 1;
+					break;
+				case LineBreakMode.TailTruncation:
+					nativeLabel.LineBreakMode = UILineBreakMode.TailTruncation;
+					maxLines = 1;
+					break;
+			}
+
+			nativeLabel.Lines = maxLines;
+		}
+
 		public static void UpdateTextDecorations(this UILabel nativeLabel, ILabel label)
 		{
 			if (nativeLabel.AttributedText != null && !(nativeLabel.AttributedText?.Length > 0))

src/Core/tests/DeviceTests/AssertionExtensions.Android.cs

@@ -2,6 +2,7 @@
 using System.IO;
 using System.Threading.Tasks;
 using Android.Graphics;
+using Android.Text;
 using Android.Views;
 using Android.Widget;
 using Xunit;
@@ -168,5 +169,17 @@ public static async Task<Bitmap> AssertColorAtTopRight(this AView view, AColor e
 			var bitmap = await view.ToBitmap();
 			return bitmap.AssertColorAtTopRight(expectedColor);
 		}
+
+		public static TextUtils.TruncateAt ToNative(this LineBreakMode mode) =>
+			mode switch
+			{
+				LineBreakMode.NoWrap => null,
+				LineBreakMode.WordWrap => null,
+				LineBreakMode.CharacterWrap => null,
+				LineBreakMode.HeadTruncation => TextUtils.TruncateAt.Start,
+				LineBreakMode.TailTruncation => TextUtils.TruncateAt.End,
+				LineBreakMode.MiddleTruncation => TextUtils.TruncateAt.Middle,
+				_ => throw new ArgumentOutOfRangeException(nameof(mode))
+			};
 	}
 }

src/Core/tests/DeviceTests/AssertionExtensions.iOS.cs

@@ -183,5 +183,17 @@ public static UIImage AssertContainsColor(this UIImage bitmap, UIColor expectedC
 			Assert.True(false, CreateColorError(bitmap, $"Color {expectedColor} not found."));
 			return bitmap;
 		}
+
+		public static UILineBreakMode ToNative(this LineBreakMode mode) =>
+		mode 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,
+			_ => throw new ArgumentOutOfRangeException(nameof(mode))
+		};
 	}
 }

src/Core/tests/DeviceTests/Handlers/Label/LabelHandlerTests.Android.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Threading.Tasks;
 using Android.Graphics;
+using Android.Text;
 using Android.Widget;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Maui.DeviceTests.Stubs;
@@ -38,6 +39,21 @@ public async Task FontFamilyInitializesCorrectly(string family)
 				Assert.NotEqual(fontManager.DefaultTypeface, nativeLabel.Typeface);
 		}
 
+		[Fact(DisplayName = "Negative MaxLines value with wrap is correct")]
+		public async Task NegativeMaxValueWithWrapIsCorrect()
+		{
+			var label = new LabelStub()
+			{
+				Text = "Lorem ipsum dolor sit amet, consectetur adipiscing elit",
+				MaxLines = -1,
+				LineBreakMode = LineBreakMode.WordWrap
+			};
+
+			var nativeValue = await GetValueAsync(label, GetNativeMaxLines);
+
+			Assert.Equal(int.MaxValue, nativeValue);
+		}
+
 		[Fact(DisplayName = "Padding Initializes Correctly")]
 		public async Task PaddingInitializesCorrectly()
 		{
@@ -128,6 +144,9 @@ Task ValidateNativeBackgroundColor(ILabel label, Color color)
 		double GetNativeCharacterSpacing(LabelHandler labelHandler) =>
 			Math.Round(GetNativeLabel(labelHandler).LetterSpacing / UnitExtensions.EmCoefficient, 4);
 
+		TextUtils.TruncateAt GetNativeLineBreakMode(LabelHandler labelHandler) =>
+			GetNativeLabel(labelHandler).Ellipsize;
+
 		PaintFlags GetNativeTextDecorations(LabelHandler labelHandler) =>
 			GetNativeLabel(labelHandler).PaintFlags;
 	}