Fix Switch Off Track Color - Fixes #10099 (#10758)

* Add a default color to the track in the off position * remove unneeded using statement * Use UIColor to handle dark mode * remove noise * Add tests and add null checks for getting subviews * add new lines * Move the tests into the iOS Test * remove UIKit on the shared file * - fix checkbox test * fix style * removing the few unneeded changes * move the code from the mapper to the extensions * move from extension to mapper and use FirstOrDefault * Auto-format source code * change test name and make color a static var * use Manuels NoLink alternative * move to arrayExtensions and use different implementation * allow param to be null --------- Co-authored-by: TJ Lambert <[email protected]> Co-authored-by: Shane Neuville <[email protected]> Co-authored-by: GitHub Actions Autoformatter <[email protected]>
dotnet · Apr 3, 2023 · 9e72fbc · 9e72fbc
1 parent e2448f1
commit 9e72fbc
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Showing 4 changed files with 118 additions and 19 deletions.
diff --git a/src/Core/src/Extensions/ArrayExtensions.cs b/src/Core/src/Extensions/ArrayExtensions.cs
@@ -64,5 +64,7 @@ public static T[] RemoveAt<T>(this T[] self, int index)
 		/// <param name="self">The array to retrieve the last item from.</param>
 		/// <returns>An object of type <typeparamref name="T"/> that is the last item in the collection.</returns>
 		public static T Last<T>(this T[] self) => self[self.Length - 1];
+
+		internal static T? FirstOrDefaultNoLinq<T>(this T[]? items) => items is null || items.Length == 0 ? default : items[0];
 	}
 }
diff --git a/src/Core/src/Handlers/Switch/SwitchHandler.iOS.cs b/src/Core/src/Handlers/Switch/SwitchHandler.iOS.cs
@@ -35,6 +35,7 @@ protected override void DisconnectHandler(UISwitch platformView)
 
 		public static void MapIsOn(ISwitchHandler handler, ISwitch view)
 		{
+			UpdateIsOn(handler);
 			handler.PlatformView?.UpdateIsOn(view);
 		}
 
@@ -55,5 +56,10 @@ void OnControlValueChanged(object? sender, EventArgs e)
 
 			VirtualView.IsOn = PlatformView.On;
 		}
+
+		static void UpdateIsOn(ISwitchHandler handler)
+		{
+			handler.UpdateValue(nameof(ISwitch.TrackColor));
+		}
 	}
 }
diff --git a/src/Core/src/Platform/iOS/SwitchExtensions.cs b/src/Core/src/Platform/iOS/SwitchExtensions.cs
@@ -1,12 +1,12 @@
 using System;
-using System.Linq;
-using ObjCRuntime;
 using UIKit;
 
 namespace Microsoft.Maui.Platform
 {
 	public static class SwitchExtensions
 	{
+		static UIColor DefaultBackgroundColor = UIColor.FromRGBA(120, 120, 128, 40);
+
 		public static void UpdateIsOn(this UISwitch uiSwitch, ISwitch view)
 		{
 			uiSwitch.SetState(view.IsOn, true);
@@ -17,17 +17,23 @@ public static void UpdateTrackColor(this UISwitch uiSwitch, ISwitch view)
 			if (view == null)
 				return;
 
-			if (view.TrackColor != null)
-				uiSwitch.OnTintColor = view.TrackColor.ToPlatform();
+			var uIView = GetTrackSubview(uiSwitch);
 
-			UIView uIView;
-			if (OperatingSystem.IsIOSVersionAtLeast(13) || OperatingSystem.IsTvOSVersionAtLeast(13))
-				uIView = uiSwitch.Subviews[0].Subviews[0];
-			else
-				uIView = uiSwitch.Subviews[0].Subviews[0].Subviews[0];
+			if (uIView is null)
+				return;
+
+			if (!view.IsOn)
+			{
+				// iOS 13+ uses the UIColor.SecondarySystemFill to support Light and Dark mode
+				// else, use the RGBA equivalent of UIColor.SecondarySystemFill in Light mode
+				uIView.BackgroundColor = OperatingSystem.IsIOSVersionAtLeast(13) ? UIColor.SecondarySystemFill : DefaultBackgroundColor;
+			}
 
-			if (view.TrackColor != null)
+			else if (view.TrackColor is not null)
+			{
+				uiSwitch.OnTintColor = view.TrackColor.ToPlatform();
 				uIView.BackgroundColor = uiSwitch.OnTintColor;
+			}
 		}
 
 		public static void UpdateThumbColor(this UISwitch uiSwitch, ISwitch view)
@@ -40,20 +46,17 @@ public static void UpdateThumbColor(this UISwitch uiSwitch, ISwitch view)
 				uiSwitch.ThumbTintColor = thumbColor?.ToPlatform();
 		}
 
-		internal static UIView GetTrackSubview(this UISwitch uISwitch)
+		internal static UIView? GetTrackSubview(this UISwitch uISwitch)
 		{
-			UIView uIView;
 			if (OperatingSystem.IsIOSVersionAtLeast(13) || OperatingSystem.IsTvOSVersionAtLeast(13))
-				uIView = uISwitch.Subviews[0].Subviews[0];
+				return uISwitch.Subviews?.FirstOrDefaultNoLinq()?.Subviews?.FirstOrDefaultNoLinq();
 			else
-				uIView = uISwitch.Subviews[0].Subviews[0].Subviews[0];
-
-			return uIView;
+				return uISwitch.Subviews?.FirstOrDefaultNoLinq()?.Subviews?.FirstOrDefaultNoLinq()?.Subviews?.FirstOrDefaultNoLinq();
 		}
 
-		internal static UIColor? GetOffTrackColor(this UISwitch uISwitch)
+		internal static UIColor? GetTrackColor(this UISwitch uISwitch)
 		{
-			return uISwitch.GetTrackSubview().BackgroundColor;
+			return uISwitch.GetTrackSubview()?.BackgroundColor;
 		}
 	}
 }
diff --git a/src/Core/tests/DeviceTests/Handlers/Switch/SwitchHandlerTests.iOS.cs b/src/Core/tests/DeviceTests/Handlers/Switch/SwitchHandlerTests.iOS.cs
@@ -54,6 +54,38 @@ async Task ValidateThumbColor(ISwitch switchStub, Color color, Action action = n
 			Assert.Equal(expected, color);
 		}
 
+		async Task ValidateVisualTrackColor(ISwitch switchStub, UIColor color)
+		{
+			var actualBackgroundColor = await GetValueAsync(switchStub, handler =>
+			{
+				var uISwitch = GetNativeSwitch(handler);
+				var uIView = uISwitch.GetTrackSubview();
+				return uIView?.BackgroundColor;
+			});
+
+			Assert.NotNull(actualBackgroundColor);
+
+			// Compare the actual RGBA values since UIColor can be picky
+			actualBackgroundColor.GetRGBA(out var actualRed, out var actualGreen, out var actualBlue, out var actualAlpha);
+			color.GetRGBA(out var colorRed, out var colorGreen, out var colorBlue, out var colorAlpha);
+
+			Assert.True(actualRed == colorRed);
+			Assert.True(actualGreen == colorGreen);
+			Assert.True(actualBlue == colorBlue);
+			Assert.True(actualAlpha == colorAlpha);
+		}
+
+		async Task ValidateTrackSubViewExists(ISwitch switchStub)
+		{
+			var uIView = await GetValueAsync(switchStub, handler =>
+			{
+				var uISwitch = GetNativeSwitch(handler);
+				return uISwitch.GetTrackSubview();
+			});
+
+			Assert.NotNull(uIView);
+		}
+
 		/// <summary>
 		/// If a UISwitch grows beyond 101 pixels it's no longer
 		/// clickable via Voice Over
@@ -72,5 +104,61 @@ public async Task EnsureUISwitchStaysBelow101Width()
 
 			Assert.True(width < 100, $"UISwitch width is too much {width}");
 		}
+
+		[Fact(DisplayName = "Track Color's view is set when toggled on")]
+		public async Task OnTrackColorSetVisually()
+		{
+			var switchStub = new SwitchStub()
+			{
+				IsOn = false,
+				TrackColor = Colors.Red,
+			};
+
+			await InvokeOnMainThreadAsync(async () =>
+			{
+				await ValidatePropertyUpdatesValue(
+					view: switchStub,
+					property: nameof(ISwitch.IsOn),
+					GetPlatformValue: (handler) => handler.PlatformView.On,
+					expectedSetValue: true,
+					expectedUnsetValue: false);
+
+				await ValidateVisualTrackColor(switchStub, UIColor.Red);
+			});
+		}
+
+		[Fact(DisplayName = "Track Color's view is default color when toggled off")]
+		public async Task OffTrackColorSetToDefaultColor()
+		{
+			var switchStub = new SwitchStub()
+			{
+				IsOn = true,
+			};
+
+			await InvokeOnMainThreadAsync(async () =>
+			{
+				await ValidatePropertyUpdatesValue(
+					view: switchStub,
+					property: nameof(ISwitch.IsOn),
+					GetPlatformValue: (handler) => handler.PlatformView.On,
+					expectedSetValue: false,
+					expectedUnsetValue: true);
+
+				var color = OperatingSystem.IsIOSVersionAtLeast(13) ? UIColor.SecondarySystemFill : UIColor.FromRGBA(120, 120, 128, 40);
+
+				await ValidateVisualTrackColor(switchStub, color);
+			});
+		}
+
+		[Fact(DisplayName = "Apple has not changed UITrack Subviews")]
+		public async Task UIViewSubviewExists()
+		{
+			var switchStub = new SwitchStub();
+
+			await InvokeOnMainThreadAsync(async () =>
+			{
+				await ValidateTrackSubViewExists(switchStub);
+			});
+		}
 	}
-}
+}