[Android] Fixed the Incorrect Text Color Applied to Selected Tab in TabbedPage (#28844)

* Fixed the Incorrect Text Color Applied to Selected Tab in TabbedPage on Android

* Added pending snap and optimized the fix

Author: Ahamed-Ali

src/Controls/src/Core/Platform/Android/TabbedPageManager.cs

@@ -635,26 +635,23 @@ protected virtual ColorStateList GetItemTextColorStates()
 			}
 			else
 			{
-				if (barItemColor is not null)
-					defaultColor = barItemColor.ToPlatform().ToArgb();
+				// UnSelected tabs TextColor
+				defaultColor = GetItemTextColor(barItemColor, _originalTabTextColors);
 
-				if (barItemColor is null && _originalTabTextColors is not null)
-					defaultColor = _originalTabTextColors.DefaultColor;
-
-				if (!defaultColor.HasValue)
-					return _originalTabTextColors;
-				else
-					checkedColor = defaultColor.Value;
-
-				if (barSelectedItemColor is not null)
-					checkedColor = barSelectedItemColor.ToPlatform().ToArgb();
+				// Selected tabs TextColor
+				checkedColor = GetItemTextColor(barSelectedItemColor, _originalTabTextColors);
 			}
 
 			_newTabTextColors = GetColorStateList(defaultColor.Value, checkedColor);
 
 			return _newTabTextColors;
 		}
 
+		int GetItemTextColor(Color customColor, ColorStateList originalColors)
+		{
+			return customColor?.ToPlatform().ToArgb() ?? originalColors?.DefaultColor ?? 0;
+		}
+
 		protected virtual ColorStateList GetItemIconTintColorState()
 		{
 			if (_orignalTabIconColors is null)

src/Controls/tests/TestCases.Android.Tests/snapshots/android/DefaultSelectedTabTextColorShouldApplyProperly.png

@@ -0,0 +1,75 @@
+namespace Maui.Controls.Sample.Issues;
+[Issue(IssueTracker.Github, 28838, "Incorrect Text Color Applied to Selected Tab in TabbedPage on Android", PlatformAffected.Android)]
+public class Issue28838 : TabbedPage
+{
+    public Issue28838()
+    {
+        // Set the UnselectedTabColor property , it should be applied only to the unselected tab.
+        UnselectedTabColor = Colors.Red;
+
+        // Add tabs (pages)
+        Children.Add(new Issue28838Tab1());
+        Children.Add(new Issue28838Tab2());
+        Children.Add(new Issue28838Tab3());
+    }
+}
+
+public class Issue28838Tab1 : ContentPage
+{
+    public Issue28838Tab1()
+    {
+        Title = "Tab 1";
+        var verticalStackLayout = new VerticalStackLayout
+        {
+            VerticalOptions = LayoutOptions.Center,
+            Children = {
+                    new Label
+                        {
+                            HorizontalOptions = LayoutOptions.Center,
+                            Text = "Tab 1",
+                            AutomationId = "Tab1"
+                        },
+                    }
+        };
+        Content = verticalStackLayout;
+    }
+}
+
+public class Issue28838Tab2 : ContentPage
+{
+    public Issue28838Tab2()
+    {
+        Title = "Tab 2";
+        var verticalStackLayout = new VerticalStackLayout
+        {
+            VerticalOptions = LayoutOptions.Center,
+            Children = {
+                    new Label
+                        {
+                            HorizontalOptions = LayoutOptions.Center,
+                            Text = "Tab 2"
+                        }
+                    }
+        };
+        Content = verticalStackLayout;
+    }
+}
+public class Issue28838Tab3 : ContentPage
+{
+    public Issue28838Tab3()
+    {
+        Title = "Tab 3";
+        var verticalStackLayout = new VerticalStackLayout
+        {
+            VerticalOptions = LayoutOptions.Center,
+            Children = {
+                    new Label
+                        {
+                            HorizontalOptions = LayoutOptions.Center,
+                            Text = "Tab 3"
+                        }
+                    }
+        };
+        Content = verticalStackLayout;
+    }
+}

src/Controls/tests/TestCases.HostApp/Issues/Issue28838.cs

@@ -0,0 +1,19 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+public class Issue28838 : _IssuesUITest
+{
+    public Issue28838(TestDevice device) : base(device) { }
+
+    public override string Issue => "Incorrect Text Color Applied to Selected Tab in TabbedPage on Android";
+
+    [Test]
+    [Category(UITestCategories.TabbedPage)]
+    public void DefaultSelectedTabTextColorShouldApplyProperly()
+    {
+        App.WaitForElement("Tab1");
+        VerifyScreenshot();
+    }
+}