LineHeight and decorations for HTML Label - fix

[kubaflo]

Note

Are you waiting for the changes in this PR to be merged?
It would be very helpful if you could test the resulting artifacts from this PR and let us know in a comment if this change resolves your issue. Thank you!

Description of Change

Corrects mapping logic for LineHeight, TextDecorations, and CharacterSpacing to apply to HTML labels. Updates iOS handler to refresh these properties when TextType changes. Adds test case for Issue22197 to verify correct rendering of HTML labels with these properties.

Issues Fixed

Fixes #22193
Fixes #22197

Before	After

Before	After

[Copilot]

Pull Request Overview

This PR fixes issues with LineHeight, TextDecorations, and CharacterSpacing not being applied to HTML labels in .NET MAUI. The fix corrects the mapping logic to allow these properties to work with HTML text type labels, not just plain text labels.

• Updates the mapper conditions to check for FormattedTextSpans instead of plain text, allowing HTML labels to receive these style properties
• Modifies the iOS handler to refresh LineHeight, TextDecorations, and CharacterSpacing when TextType changes
• Adds comprehensive test case to verify the fix works correctly

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/Controls/src/Core/Label/Label.Mapper.cs	Updates mapping conditions from IsPlainText check to HasFormattedTextSpans check for LineHeight, TextDecorations, and CharacterSpacing
src/Controls/src/Core/Label/Label.iOS.cs	Adds refresh calls for LineHeight, TextDecorations, and CharacterSpacing when TextType changes in iOS handler
src/Controls/tests/TestCases.HostApp/Issues/Issue22197.xaml	Creates UI test page demonstrating HTML vs plain text labels with styling properties
src/Controls/tests/TestCases.HostApp/Issues/Issue22197.xaml.cs	Code-behind for the test page
src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue22197.cs	NUnit test implementation to verify the fix through screenshot verification

[Copilot]

The AutomationId 'label' is too generic and could conflict with other elements. Consider using a more specific identifier like 'htmlTextTypeLabel' to ensure uniqueness across all test cases.

[dotnet-policy-service]

Hey there @@kubaflo! Thank you so much for your PR! Someone from the team will get assigned to your PR shortly and we'll get it reviewed.

[MartyIX]

This is how it looks like on Windows:

(For reference purposes)

[MartyIX]

This would exercise the line height feature more:

Suggested change

	</VerticalStackLayout>
	<!-- Exercise line heights less than 1. -->
	<Label BackgroundColor="Green" FontSize="20" Text="ÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑ"/>
	<Label BackgroundColor="Red" LineHeight="0.8" FontSize="20" Text="ÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑ"/>
	<Label BackgroundColor="Green" LineHeight="0.2" FontSize="20" Text="ÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑ"/>
	<Label BackgroundColor="Red" LineHeight="0.4" FontSize="20" Text="ÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑ"/>
	<Label BackgroundColor="Green" LineHeight="1.0" FontSize="20" Text="ÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑ"/>
	<Label BackgroundColor="Red" LineHeight="1.2" FontSize="20" Text="ÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑ"/>
	<Label BackgroundColor="Green" LineHeight="1.4" FontSize="20" Text="ÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑ"/>
	<Label BackgroundColor="Red" LineHeight="1.6" FontSize="20" Text="ÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑ"/>
	<Label BackgroundColor="Green" LineHeight="2.0" FontSize="20" Text="ÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑ"/>
	<Label BackgroundColor="Red" LineHeight="4.6" FontSize="20" Text="ÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑ"/>
	</VerticalStackLayout>

See comment #24520 (comment)

[kubaflo]

Hmmm but this pr is not about lineHeight in this sense. It is about the line Height for HTML labels

[MartyIX]

Good point. I moved the comment to #31219.