Only use custom image sizing with ImageButtons (#18521)

* Only use custom sizing with ImageButtons

ImageButtons have a null value for CurrentTitle and can't have Text on them, giving us a way to distinguish Imagebuttons from normal buttons.

Normal buttons with images should still use the standard sizing logic

* Add test

src/Controls/tests/DeviceTests/Elements/Button/ButtonTests.iOS.cs

@@ -2,6 +2,7 @@
 using System;
 using System.Threading.Tasks;
 using Microsoft.Maui.Controls;
+using Microsoft.Maui.Graphics;
 using Microsoft.Maui.Handlers;
 using UIKit;
 using Xunit;
@@ -36,5 +37,46 @@ public async Task ClickedWorksAfterGC()
 			await InvokeOnMainThreadAsync(() => handler.PlatformView.SendActionForControlEvents(UIControlEvent.TouchUpInside));
 			Assert.True(fired, "Button.Clicked did not fire!");
 		}
+
+		[Theory("Button with image lays out correctly")]
+		[InlineData(true)]
+		[InlineData(false)]
+		public async Task ButtonWithImage(bool includeText)
+		{
+			var gridHeight = 300;
+			var gridWidth = 300;
+
+			var button = new Button {BackgroundColor = Colors.Yellow, VerticalOptions = LayoutOptions.Center, HorizontalOptions = LayoutOptions.Center};
+			if (includeText)
+			{
+				button.Text = "Hello world!";
+			}
+
+			var layout = new Grid() {HeightRequest = gridHeight, WidthRequest = gridWidth, BackgroundColor = Colors.Blue };
+			layout.Add(button);
+
+			var buttonHandler = await CreateHandlerAsync<ButtonHandler>(button);
+			var handler = await CreateHandlerAsync<LayoutHandler>(layout);
+
+			await InvokeOnMainThreadAsync(async () =>
+			{
+				button.ImageSource = ImageSource.FromFile("red.png"); 
+
+				// Wait for image to load and force the grid to measure itself again
+				await Task.Delay(1000);
+				layout.Measure(double.PositiveInfinity, double.PositiveInfinity);
+
+				await handler.ToPlatform().AssertContainsColor(Colors.Blue, MauiContext); // Grid renders
+				await handler.ToPlatform().AssertContainsColor(Colors.Red, MauiContext); // Image within button renders
+				await handler.ToPlatform().AssertContainsColor(Colors.Yellow, MauiContext); // Button renders
+			});
+
+			// red.png is 100x100
+			Assert.True(button.Width > 100, $"Button should have larger width than its image. Exepected: 100>, was {button.Width}");
+			Assert.True(button.Height > 100, $"Button should have larger height than its image. Exepected: 100>, was {button.Height}");
+
+			Assert.True(button.Width < gridWidth, $"Button shouldn't occupy entire layout width. Expected: {gridWidth}<, was {button.Width}");
+			Assert.True(button.Height < gridHeight, $"Button shouldn't occupy entire layout height. Expected: {gridHeight}<, was {button.Height}");
+		}
 	}
 }

src/Core/src/Handlers/ViewHandlerExtensions.iOS.cs

@@ -89,7 +89,7 @@ internal static Size GetDesiredSizeFromHandler(this IViewHandler viewHandler, do
 
 				sizeThatFits = imageView.SizeThatFitsImage(new CGSize((float)widthConstraint, (float)heightConstraint));
 			}
-			else if (platformView is UIButton imageButton && imageButton.ImageView?.Image is not null)
+			else if (platformView is UIButton imageButton && imageButton.ImageView?.Image is not null && imageButton.CurrentTitle is null)
 			{
 				widthConstraint = IsExplicitSet(virtualView.Width) ? virtualView.Width : widthConstraint;
 				heightConstraint = IsExplicitSet(virtualView.Height) ? virtualView.Height : heightConstraint;

src/Core/src/Platform/iOS/WrapperView.cs

@@ -126,7 +126,7 @@ public override CGSize SizeThatFits(CGSize size)
 			{
 				return imageView.SizeThatFitsImage(size);
 			}
-			else if (child is UIButton imageButton && imageButton.ImageView?.Image is not null)
+			else if (child is UIButton imageButton && imageButton.ImageView?.Image is not null && imageButton.CurrentTitle is null)
 			{
 				return imageButton.ImageView.SizeThatFitsImage(size);
 			}
@@ -141,7 +141,7 @@ internal CGSize SizeThatFitsWrapper(CGSize originalSpec, double virtualViewWidth
 
 			var child = Subviews[0];
 
-			if (child is UIImageView || (child is UIButton imageButton && imageButton.ImageView?.Image is not null))
+			if (child is UIImageView || (child is UIButton imageButton && imageButton.ImageView?.Image is not null && imageButton.CurrentTitle is null))
 			{
 				var widthConstraint = IsExplicitSet(virtualViewWidth) ? virtualViewWidth : originalSpec.Width;
 				var heightConstraint = IsExplicitSet(virtualViewHeight) ? virtualViewHeight : originalSpec.Height;