Fix SplitView :closed pseudoclass not being added on control initialization #17176

[OccVeneficus]

What does the pull request do?

This PR resolves the issue where the :closed pseudoclass was not set on control initialization if the IsPaneOpen property of the SplitView control had its default value (false) (issue #17176)

What is the current behavior?

Currently, if value of IsPaneOpen before control first renders is false, the :closed pseudoclass will not be added, which may cause issues with styling.

What is the updated/expected behavior with this PR?

:closed pseudoclass would be present right after control with IsPaneOpen = false rendered

How was the solution implemented (if it's not obvious)?

In the original code, the addition or removal of the :closed / :open pseudoclass occurred only in the OnPropertyChanged method.
Since IsPaneOpen is of type bool, and the default value of bool is false, if a SplitView instance is created with IsPaneOpen = false, the OnPropertyChanged method will not be called.

Checklist

• Added unit tests (if possible)?
• Added XML documentation to any related classes?
• Consider submitting a PR to https://github.com/AvaloniaUI/avalonia-docs with user documentation

Fixed issues

Fixes #17176

[MrJul]

Thank you for your contribution!

The existing test SplitViewTests.SplitView_TemplateSettings_Are_Correct_For_Display_Modes is now failing because animations are triggered and there's no IGlobalClock registered in that test.

You need to change the UnitTestApplication to use a GlobalClock, as you can see in several other tests in that file:

using var app = UnitTestApplication.Start(TestServices.StyledWindow
                .With(globalClock: new MockGlobalClock()));

Aside from that issue, LGTM!

[cla-avalonia]

@OccVeneficus,

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[OccVeneficus]

@OccVeneficus,

Please read the following Contributor License Agreement (CLA). If you agree with the CLA, please reply with the following:

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[avaloniaui-bot]

You can test this PR using the following package version. 11.2.999-cibuild0052342-alpha. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]

[avaloniaui-bot]

You can test this PR using the following package version. 11.2.999-cibuild0052346-alpha. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]

[MrJul]

LGTM, thanks!