[iOS/Win] Label will not unnecessarily expand (#827)

* Add repro for 53362

* [iOS] Label will not unnecessarily expand

* [Win] Label will not unnecessarily expand

Author: samhouts

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla53362.cs

@@ -0,0 +1,35 @@
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+
+namespace Xamarin.Forms.Controls.Issues
+{
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Bugzilla, 53362, "Layout regression in Grid on iOS: HorizontalOption = Center does not center", PlatformAffected.iOS)]
+	public class Bugzilla53362 : TestContentPage
+	{
+		protected override void Init()
+		{
+			var label1 = new Label { Text = "auto sized row", TextColor = Color.Silver, HorizontalOptions = LayoutOptions.Center, BackgroundColor = Color.Purple };
+			var label2 = new Label { Text = "row size 20", TextColor = Color.Silver, HorizontalOptions = LayoutOptions.Center, BackgroundColor = Color.Purple };
+			var label3 = new Label { Text = "row size 25", TextColor = Color.Silver, HorizontalOptions = LayoutOptions.Center, BackgroundColor = Color.Purple };
+
+			var grid = new Grid
+			{
+				RowDefinitions =
+				{
+					new RowDefinition { Height = new GridLength(1, GridUnitType.Auto) },
+					new RowDefinition { Height = new GridLength(20, GridUnitType.Absolute) },
+					new RowDefinition { Height = new GridLength(25, GridUnitType.Absolute) },
+					new RowDefinition { Height = new GridLength(1, GridUnitType.Auto) },
+				}
+			};
+
+			grid.Children.Add(label1, 0, 0);
+			grid.Children.Add(label2, 0, 1);
+			grid.Children.Add(label3, 0, 2);
+			grid.Children.Add(new Label { Text = "If the three labels above are not all centered horizontally, this test has failed." }, 0, 3);
+
+			Content = grid;
+		}
+	}
+}

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

@@ -235,6 +235,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla51503.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla51505.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla52533.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Bugzilla53362.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)_Template.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue1028.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue1075.cs" />

Xamarin.Forms.Platform.WinRT/LabelRenderer.cs

@@ -72,15 +72,31 @@ public override SizeRequest GetDesiredSize(double widthConstraint, double height
 				_perfectSizeValid = true;
 			}
 
-			if (widthConstraint >= _perfectSize.Request.Width && heightConstraint >= _perfectSize.Request.Height)
+			var widthFits = widthConstraint >= _perfectSize.Request.Width;
+			var heightFits = heightConstraint >= _perfectSize.Request.Height;
+
+			if (widthFits && heightFits)
 				return _perfectSize;
 
 			var result = base.GetDesiredSize(widthConstraint, heightConstraint);
-			result.Minimum = new Size(Math.Min(10, result.Request.Width), result.Request.Height);
-			if (Element.LineBreakMode != LineBreakMode.NoWrap)
+			var tinyWidth = Math.Min(10, result.Request.Width);
+			result.Minimum = new Size(tinyWidth, result.Request.Height);
+
+			if (widthFits || Element.LineBreakMode == LineBreakMode.NoWrap)
+				return result;
+
+			bool containerIsNotInfinitelyWide = !double.IsInfinity(widthConstraint);
+
+			if (containerIsNotInfinitelyWide)
 			{
-				if (result.Request.Width > widthConstraint || Element.LineBreakMode == LineBreakMode.WordWrap || Element.LineBreakMode == LineBreakMode.CharacterWrap)
-					result.Request = new Size(Math.Max(result.Minimum.Width, widthConstraint), result.Request.Height);
+				bool textCouldHaveWrapped = Element.LineBreakMode == LineBreakMode.WordWrap || Element.LineBreakMode == LineBreakMode.CharacterWrap;
+				bool textExceedsContainer = result.Request.Width > widthConstraint;
+
+				if (textExceedsContainer || textCouldHaveWrapped)
+				{
+					var expandedWidth = Math.Max(tinyWidth, widthConstraint);
+					result.Request = new Size(expandedWidth, result.Request.Height);
+				}
 			}
 
 			return result;

Xamarin.Forms.Platform.iOS/Renderers/LabelRenderer.cs

@@ -21,16 +21,31 @@ public override SizeRequest GetDesiredSize(double widthConstraint, double height
 				_perfectSizeValid = true;
 			}
 
-			if (widthConstraint >= _perfectSize.Request.Width && heightConstraint >= _perfectSize.Request.Height)
+			var widthFits = widthConstraint >= _perfectSize.Request.Width;
+			var heightFits = heightConstraint >= _perfectSize.Request.Height;
+
+			if (widthFits && heightFits)
 				return _perfectSize;
 
 			var result = base.GetDesiredSize(widthConstraint, heightConstraint);
-			result.Minimum = new Size(Math.Min(10, result.Request.Width), result.Request.Height);
-			if (Element.LineBreakMode != LineBreakMode.NoWrap)
+			var tinyWidth = Math.Min(10, result.Request.Width);
+			result.Minimum = new Size(tinyWidth, result.Request.Height);
+
+			if (widthFits || Element.LineBreakMode == LineBreakMode.NoWrap)
+				return result;
+
+			bool containerIsNotInfinitelyWide = !double.IsInfinity(widthConstraint);
+
+			if (containerIsNotInfinitelyWide)
 			{
-				if (!double.IsInfinity(result.Request.Width) && !double.IsInfinity(widthConstraint))
-					if (result.Request.Width > widthConstraint || Element.LineBreakMode == LineBreakMode.WordWrap || Element.LineBreakMode == LineBreakMode.CharacterWrap)
-						result.Request = new Size(Math.Max(result.Minimum.Width, widthConstraint), result.Request.Height);
+				bool textCouldHaveWrapped = Element.LineBreakMode == LineBreakMode.WordWrap || Element.LineBreakMode == LineBreakMode.CharacterWrap;
+				bool textExceedsContainer = result.Request.Width > widthConstraint;
+
+				if (textExceedsContainer || textCouldHaveWrapped)
+				{
+					var expandedWidth = Math.Max(tinyWidth, widthConstraint);
+					result.Request = new Size(expandedWidth, result.Request.Height);
+				}
 			}
 
 			return result;