chore: Add comments for clarification on TabBar GetInnerContainer

unoplatform · Oct 15, 2024 · 467205c · 467205c
1 parent 8b35f42
commit 467205c
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Showing 3 changed files with 39 additions and 15 deletions.
diff --git a/src/Uno.Toolkit.RuntimeTests/Tests/TabBarTests.cs b/src/Uno.Toolkit.RuntimeTests/Tests/TabBarTests.cs
@@ -318,8 +318,13 @@ public async Task Verify_Indicator_Display_On_Selection()
 				SUT.SelectedIndex = i;
 				await UnitTestsUIContentHelper.WaitForIdle();
 
+				// When using an `ItemTemplate` with a `TabBarItem`, the container will be a `ContentPresenter` that wraps the `TabBarItem`.
+				// In that case, to access the `ContentPresenter` from a `TabBarItem`, you must first call `ContainerFromItem`.
+				// Afterward, pass the resulting `ContentPresenter` as a parameter to `GetInnerContainer`.
+				// See https://github.com/unoplatform/uno.toolkit.ui/pull/1261#discussion_r1799794554 for reference.
 				var container = SUT.ContainerFromItem(SUT.SelectedItem);
 				var selectedItem = SUT.GetInnerContainer(container);
+
 				Assert.IsNotNull(selectedItem);
 
 				var renderer = await SUT.TakeScreenshot();
@@ -428,7 +433,7 @@ public async Task Verify_SelectedIndex_Not_Set_Unnecessarily()
 		}
 
 		[TestMethod]
-		public async Task Verify_ItemTemplated_Has_No_Nested_TabBarItem()
+		public async Task Verify_ItemTemplate_Has_No_Nested_TabBarItem()
 		{
 			var source = new[]
 			{
@@ -437,11 +442,11 @@ public async Task Verify_ItemTemplated_Has_No_Nested_TabBarItem()
 				new TestRecord("True", true)
 			};
 
-			var dt = XamlHelper.LoadXaml<DataTemplate>(@"
-					<DataTemplate>
-						<utu:TabBarItem Content=""{Binding Name}"" IsSelectable=""{Binding IsSelectable}"" />
-					</DataTemplate>
-				");
+			var dt = XamlHelper.LoadXaml<DataTemplate>("""
+				<DataTemplate>
+					<utu:TabBarItem Content="{Binding Name}" IsSelectable="{Binding IsSelectable}" />
+				</DataTemplate>
+			""");
 
 			var SUT = new TabBar
 			{
@@ -453,17 +458,20 @@ public async Task Verify_ItemTemplated_Has_No_Nested_TabBarItem()
 
 			await UnitTestUIContentHelperEx.SetContentAndWait(SUT);
 
-			// Ensure the container is a `ContentPresenter` and not a `TabBarItem`
+			// When using an `ItemTemplate` with a `TabBarItem`, the container will be a `ContentPresenter` that wraps the `TabBarItem`.
+			// In that case, to access the `ContentPresenter` from a `TabBarItem`, you must first call `ContainerFromItem`.
+			// Afterward, pass the resulting `ContentPresenter` as a parameter to `GetInnerContainer`.
+			// See https://github.com/unoplatform/uno.toolkit.ui/pull/1261#discussion_r1799794554 for reference.
+
 			var container = SUT.ContainerFromItem(SUT.SelectedItem);
 			Assert.IsInstanceOfType(container, typeof(ContentPresenter));
 
-			// Ensure the inner container is a `TabBarItem`
 			var selectedItem = SUT.GetInnerContainer(container);
 			Assert.IsInstanceOfType(selectedItem, typeof(TabBarItem));
 		}
 
 		[TestMethod]
-		public async Task Verify_ItemTemplated_Disabled_Not_Selectable()
+		public async Task Verify_ItemTemplate_Disabled_Not_Selectable()
 		{
 			var source = new[]
 			{
@@ -472,11 +480,11 @@ public async Task Verify_ItemTemplated_Disabled_Not_Selectable()
 				new TestRecord("True", true)
 			};
 
-			var dt = XamlHelper.LoadXaml<DataTemplate>(@"
-					<DataTemplate>
-						<utu:TabBarItem Content=""{Binding Name}"" IsSelectable=""{Binding IsSelectable}"" />
-					</DataTemplate>
-				");
+			var dt = XamlHelper.LoadXaml<DataTemplate>("""
+				<DataTemplate>
+					<utu:TabBarItem Content="{Binding Name}" IsSelectable="{Binding IsSelectable}" />
+				</DataTemplate>
+			""");
 
 			var SUT = new TabBar
 			{

diff --git a/src/Uno.Toolkit.UI/Controls/TabBar/TabBar.cs b/src/Uno.Toolkit.UI/Controls/TabBar/TabBar.cs
@@ -148,6 +148,10 @@ e is IVectorChangedEventArgs iVCE
 				{
 					var item = Items[(int)iVCE.Index];
 
+					// When using an `ItemTemplate` with a `TabBarItem`, the container will be a `ContentPresenter` that wraps the `TabBarItem`.
+					// In that case, to access the `ContentPresenter` from a `TabBarItem`, you must first call `ContainerFromItem`.
+					// Afterward, pass the resulting `ContentPresenter` as a parameter to `GetInnerContainer`.
+					// See https://github.com/unoplatform/uno.toolkit.ui/pull/1261#discussion_r1799794554 for reference.
 					if (GetInnerContainer(item as DependencyObject) is { IsSelected: true } selected)
 					{
 						SelectedItem = selected;
@@ -355,6 +359,10 @@ private void SynchronizeSelection(TabBarItem? item)
 				var containers = this.GetItemContainers<UIElement>();
 				foreach (var container in containers)
 				{
+					// When using an `ItemTemplate` with a `TabBarItem`, the container will be a `ContentPresenter` that wraps the `TabBarItem`.
+					// In that case, to access the `ContentPresenter` from a `TabBarItem`, you must first call `ContainerFromItem`.
+					// Afterward, pass the resulting `ContentPresenter` as a parameter to `GetInnerContainer`.
+					// See https://github.com/unoplatform/uno.toolkit.ui/pull/1261#discussion_r1799794554 for reference.
 					var tbi = GetInnerContainer(container);
 					if (tbi is not { }) continue;
 
@@ -407,6 +415,10 @@ private void RaiseSelectionChangedEvent(object? prevItem, object? nextItem)
 			SelectionChanged?.Invoke(this, eventArgs);
 		}
 
+		// When using an `ItemTemplate` with a `TabBarItem`, the container will be a `ContentPresenter` that wraps the `TabBarItem`.
+		// In that case, to access the `ContentPresenter` from a `TabBarItem`, you must first call `ContainerFromItem`.
+		// Afterward, pass the resulting `ContentPresenter` as a parameter to this method.
+		// See https://github.com/unoplatform/uno.toolkit.ui/pull/1261#discussion_r1799794554 for reference.
 		internal TabBarItem? GetInnerContainer(DependencyObject? container)
 		{
 			if (IsUsingOwnContainerAsTemplateRoot && container is ContentPresenter cp)

diff --git a/src/Uno.Toolkit.UI/Controls/TabBar/TabBarSelectionIndicatorPresenter.cs b/src/Uno.Toolkit.UI/Controls/TabBar/TabBarSelectionIndicatorPresenter.cs
@@ -224,7 +224,11 @@ private void UpdateSelectionIndicatorMaxSize()
 			if (Owner is { } tabBar
 				&& GetSelectionIndicator() is { } indicator)
 			{
-				var tabBarItems =tabBar.GetItemContainers<UIElement>()
+				var tabBarItems = tabBar.GetItemContainers<UIElement>()
+					// When using an `ItemTemplate` with a `TabBarItem`, the container will be a `ContentPresenter` that wraps the `TabBarItem`.
+					// In that case, to access the `ContentPresenter` from a `TabBarItem`, you must first call `ContainerFromItem`.
+					// Afterward, pass the resulting `ContentPresenter` as a parameter to `GetInnerContainer`.
+					// See https://github.com/unoplatform/uno.toolkit.ui/pull/1261#discussion_r1799794554 for reference.
 					.Select(tabBar.GetInnerContainer)
 					.OfType<TabBarItem>();
 				var visibleItems = tabBarItems.Count(x => x.Visibility == Visibility.Visible);