GH-3106 Implemented LineBreakMode to Button

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue3106.cs

@@ -0,0 +1,101 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+
+namespace Xamarin.Forms.Controls.Issues
+{
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Github, 3106, "Added LineBreakMode on Button")]
+	public class Issue3106 : TestContentPage
+	{
+		int count;
+		const string content = "Welcome to Xamarin.Forms! Welcome to Xamarin.Forms! Welcome to Xamarin.Forms! Welcome to Xamarin.Forms!";
+		const string content2 = "Now users can set a line break mode to texts on Button, the default value doesn't affect any user.";
+
+		Button mainButton;
+		Button materialButton;
+		Label lineBreakModeType;
+
+		protected override void Init()
+		{
+			mainButton = new Button
+			{
+				Text = content,
+				LineBreakMode = LineBreakMode.WordWrap,
+				HorizontalOptions = LayoutOptions.CenterAndExpand,
+				VerticalOptions = LayoutOptions.CenterAndExpand
+			};
+			mainButton.Clicked += MainButton_Clicked;
+
+			materialButton = new Button
+			{
+				Text = content,
+				LineBreakMode = LineBreakMode.WordWrap,
+				HorizontalOptions = LayoutOptions.CenterAndExpand,
+				VerticalOptions = LayoutOptions.CenterAndExpand,
+				Visual = VisualMarker.Material
+			};
+			materialButton.Clicked += MaterialButton_Clicked;
+
+			lineBreakModeType = new Label
+			{
+				Text = LineBreakMode.WordWrap.ToString(),
+				VerticalOptions = LayoutOptions.EndAndExpand,
+				LineBreakMode = LineBreakMode.WordWrap,
+			};
+			var layout = new StackLayout
+			{
+				Children =
+				{
+					new Label
+					{
+						Text = "Press the first button to change the LineBreakMode. Press the second button to change the text",
+						VerticalOptions = LayoutOptions.StartAndExpand
+					},
+					mainButton,
+					materialButton,
+					lineBreakModeType
+				}
+			};
+
+			Content = layout;
+		}
+
+		void MaterialButton_Clicked(object sender, EventArgs e)
+		{
+			if (materialButton.Text.Equals(content2))
+				materialButton.Text = mainButton.Text = content;
+			else
+				materialButton.Text = mainButton.Text = content2;
+		}
+
+		void MainButton_Clicked(object sender, EventArgs e)
+		{
+			materialButton.LineBreakMode = mainButton.LineBreakMode = SelectLineBreakMode();
+			lineBreakModeType.Text = mainButton.LineBreakMode.ToString();
+		}
+
+		LineBreakMode SelectLineBreakMode()
+		{
+			count++;
+			switch (count)
+			{
+				case 1:
+					return LineBreakMode.CharacterWrap;
+				case 2:
+					return LineBreakMode.HeadTruncation;
+				case 3:
+					return LineBreakMode.MiddleTruncation;
+				case 4:
+					return LineBreakMode.NoWrap;
+				case 5:
+					return LineBreakMode.TailTruncation;
+				default:
+					count = 0;
+					return LineBreakMode.WordWrap;
+			}
+		}
+	}
+}

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Xamarin.Forms.Controls.Issues.Shared.projitems

@@ -26,6 +26,7 @@
     </Compile>
     <Compile Include="$(MSBuildThisFileDirectory)Issue10744.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue10909.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Issue3106.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue8613.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue9137.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue8691.cs" />

Xamarin.Forms.Core/Button.cs

@@ -59,6 +59,9 @@ public class Button : View, IFontElement, ITextElement, IBorderElement, IButtonC
 
 		public static readonly BindableProperty PaddingProperty = PaddingElement.PaddingProperty;
 
+		public static readonly BindableProperty LineBreakModeProperty = BindableProperty.Create(nameof(LineBreakMode), typeof(LineBreakMode), typeof(Button), LineBreakMode.NoWrap,
+	propertyChanged: (bindable, oldvalue, newvalue) => ((Button)bindable).InvalidateMeasureInternal(InvalidationTrigger.MeasureChanged));
+
 		public Thickness Padding
 		{
 			get { return (Thickness)GetValue(PaddingElement.PaddingProperty); }
@@ -70,6 +73,12 @@ Thickness IPaddingElement.PaddingDefaultValueCreator()
 			return default(Thickness);
 		}
 
+		public LineBreakMode LineBreakMode
+		{
+			get { return (LineBreakMode)GetValue(LineBreakModeProperty); }
+			set { SetValue(LineBreakModeProperty, value); }
+		}
+
 		void IPaddingElement.OnPaddingPropertyChanged(Thickness oldValue, Thickness newValue)
 		{
 			InvalidateMeasureInternal(InvalidationTrigger.MeasureChanged);

Xamarin.Forms.CustomAttributes/TestAttributes.cs

@@ -233,7 +233,8 @@ public enum Button
 			BorderRadius,
 			Image,
 			Padding,
-			Pressed
+			Pressed,
+			LineBreakMode
 		}
 
 		public enum VisualElement

Xamarin.Forms.Platform.Android/ButtonLayoutManager.cs

@@ -16,6 +16,7 @@
 using ARect = Android.Graphics.Rect;
 using AView = Android.Views.View;
 using AButton = Android.Widget.Button;
+using Android.Text;	
 
 namespace Xamarin.Forms.Platform.Android
 {
@@ -191,6 +192,7 @@ public void Update()
 			if (!UpdateTextAndImage())
 				UpdateImage();
 			UpdatePadding();
+			UpdateLineBreakMode();
 		}
 
 		void OnElementChanged(object sender, VisualElementChangedEventArgs e)
@@ -223,6 +225,8 @@ void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
 				UpdateTextAndImage();
 			else if (e.PropertyName == Button.BorderWidthProperty.PropertyName && _borderAdjustsPadding)
 				_element.InvalidateMeasureNonVirtual(InvalidationTrigger.MeasureChanged);
+			else if (e.PropertyName == Button.LineBreakModeProperty.PropertyName)
+				UpdateLineBreakMode();
 		}
 
 		void UpdatePadding()
@@ -355,5 +359,16 @@ void UpdateImage()
 				});
 			}
 		}
+
+		void UpdateLineBreakMode()
+		{
+			AButton view = View;
+
+			if (view == null || _element == null || _renderer?.View == null)
+				return;
+
+			view.SetLineBreakMode(_element);
+			_renderer.View.SetAllCaps(_element.TextTransform == TextTransform.Default);
+		}
 	}
 }

Xamarin.Forms.Platform.Android/Extensions/TextViewExtensions.cs

@@ -22,28 +22,26 @@ public static void SetMaxLines(this TextView textView, Label label)
 			textView.SetMaxLines(maxLines);
 		}
 
-		static void SetMaxLines(this TextView textView, Label label, int lines)
+		public static void	SetLineBreakMode(this TextView textView, Label label)
 		{
-			// If the Label's MaxLines has been explicitly set, we should not set it here
-			if (label.MaxLines != (int)Label.MaxLinesProperty.DefaultValue)
-			{
-				return;
-			}
-
-			textView.SetMaxLines(lines);
+			var maxLines = SetLineBreak(textView, label.LineBreakMode);
+			textView.SetMaxLines(maxLines);
 		}
 
-		public static void SetLineBreakMode(this TextView textView, Label label)
-		{
-			var lineBreakMode = label.LineBreakMode;
+		public static void SetLineBreakMode(this TextView textView, Button button) =>
+			SetLineBreak(textView, button.LineBreakMode);
 
+
+		public static int SetLineBreak( TextView textView, LineBreakMode lineBreakMode)
+		{
 			int maxLines = Int32.MaxValue;
 			bool singleLine = false;
 
 			switch (lineBreakMode)
 			{
 				case LineBreakMode.NoWrap:
 					maxLines = 1;
+					singleLine = true;
 					textView.Ellipsize = null;
 					break;
 				case LineBreakMode.WordWrap:
@@ -59,6 +57,7 @@ public static void SetLineBreakMode(this TextView textView, Label label)
 					break;
 				case LineBreakMode.TailTruncation:
 					maxLines = 1;
+					singleLine = true;
 					textView.Ellipsize = TextUtils.TruncateAt.End;
 					break;
 				case LineBreakMode.MiddleTruncation:
@@ -69,7 +68,7 @@ public static void SetLineBreakMode(this TextView textView, Label label)
 			}
 
 			textView.SetSingleLine(singleLine);
-			textView.SetMaxLines(label, maxLines);
+			return maxLines;
 		}
 
 		public static void RecalculateSpanPositions(this TextView textView, Label element, SpannableString spannableString, SizeRequest finalSize)

Xamarin.Forms.Platform.UAP/ButtonRenderer.cs

@@ -8,12 +8,16 @@
 using WImage = Windows.UI.Xaml.Controls.Image;
 using WStretch = Windows.UI.Xaml.Media.Stretch;
 using WThickness = Windows.UI.Xaml.Thickness;
+using System;
+using Xamarin.Forms.Platform.UAP.Extensions;
+using System.Linq;
 
 namespace Xamarin.Forms.Platform.UWP
 {
 	public class ButtonRenderer : ViewRenderer<Button, FormsButton>
 	{
 		bool _fontApplied;
+		TextBlock _textBlock = null;
 
 		FormsButton _button;
 		PointerEventHandler _pointerPressedHandler;		
@@ -74,6 +78,15 @@ protected override void OnElementChanged(ElementChangedEventArgs<Button> e)
 		void ButtonOnLoaded(object o, RoutedEventArgs routedEventArgs)
 		{
 			WireUpFormsVsm();
+			UpdateLineBreakMode();
+		}
+
+
+		void UpdateLineBreakMode()
+		{
+			_textBlock = Control.GetTextBlock(Control.Content);
+
+			_textBlock?.UpdateLineBreakMode(Element.LineBreakMode);
 		}
 
 		void WireUpFormsVsm()
@@ -124,6 +137,8 @@ protected override void OnElementPropertyChanged(object sender, PropertyChangedE
 			{
 				UpdatePadding();
 			}
+			else if (e.PropertyName == Button.LineBreakModeProperty.PropertyName)
+				UpdateLineBreakMode();
 		}
 
 		protected override void UpdateBackgroundColor()
@@ -188,8 +203,9 @@ async void UpdateContent()
 			// No image, just the text
 			if (elementImage == null)
 			{
-				Control.Content = text;
+				Control.Content = new TextBlock { Text = text };
 				Element?.InvalidateMeasureNonVirtual(InvalidationTrigger.RendererReady);
+				UpdateLineBreakMode();
 				return;
 			}
 
@@ -208,7 +224,8 @@ async void UpdateContent()
 			// when this happens, we want to resize the button
 			if (elementImage is BitmapImage bmp)
 			{
-				bmp.ImageOpened += (sender, args) => {
+				bmp.ImageOpened += (sender, args) =>
+				{
 					var actualSize = bmp.GetImageSourceSize();
 					image.Width = actualSize.Width;
 					image.Height = actualSize.Height;
@@ -227,12 +244,14 @@ async void UpdateContent()
 			// Both image and text, so we need to build a container for them
 			Control.Content = CreateContentContainer(Element.ContentLayout, image, text);
 			Element?.InvalidateMeasureNonVirtual(InvalidationTrigger.RendererReady);
+			UpdateLineBreakMode();
 		}
 
 		static StackPanel CreateContentContainer(Button.ButtonContentLayout layout, WImage image, string text)
 		{
 			var container = new StackPanel();
-			var textBlock = new TextBlock {
+			var textBlock = new TextBlock
+			{
 				Text = text,
 				VerticalAlignment = VerticalAlignment.Center,
 				HorizontalAlignment = HorizontalAlignment.Center

Xamarin.Forms.Platform.UAP/Extensions/TextBlockExtensions.cs

@@ -0,0 +1,50 @@
+using System;
+using Windows.UI.Xaml;
+using Windows.UI.Xaml.Controls;
+
+namespace Xamarin.Forms.Platform.UAP.Extensions
+{
+	internal static class TextBlockExtensions
+	{
+		public static void UpdateLineBreakMode(this TextBlock textBlock, LineBreakMode lineBreakMode)
+		{
+			if (textBlock == null)
+				return;
+
+			switch (lineBreakMode)
+			{
+				case LineBreakMode.NoWrap:
+					textBlock.TextTrimming = TextTrimming.Clip;
+					textBlock.TextWrapping = TextWrapping.NoWrap;
+					break;
+				case LineBreakMode.WordWrap:
+					textBlock.TextTrimming = TextTrimming.None;
+					textBlock.TextWrapping = TextWrapping.Wrap;
+					break;
+				case LineBreakMode.CharacterWrap:
+					textBlock.TextTrimming = TextTrimming.WordEllipsis;
+					textBlock.TextWrapping = TextWrapping.Wrap;
+					break;
+				case LineBreakMode.HeadTruncation:
+					// TODO: This truncates at the end.
+					textBlock.TextTrimming = TextTrimming.WordEllipsis;
+					DetermineTruncatedTextWrapping(textBlock);
+					break;
+				case LineBreakMode.TailTruncation:
+					textBlock.TextTrimming = TextTrimming.CharacterEllipsis;
+					DetermineTruncatedTextWrapping(textBlock);
+					break;
+				case LineBreakMode.MiddleTruncation:
+					// TODO: This truncates at the end.
+					textBlock.TextTrimming = TextTrimming.WordEllipsis;
+					DetermineTruncatedTextWrapping(textBlock);
+					break;
+				default:
+					throw new ArgumentOutOfRangeException();
+			}
+		}
+
+		static void DetermineTruncatedTextWrapping(TextBlock textBlock) =>
+			textBlock.TextWrapping = textBlock.MaxLines > 1 ? TextWrapping.Wrap : TextWrapping.NoWrap;
+	}
+}