Description

When we updated the design of the Date PIcker to match the latest Material Design spec, we deprecated the existing YearPicker API as it was not seen as very useful on its own and the visuals changed. However, we have had some feedback from the community that this was still a useful widget, so this PR exposes the new YearPicker implementation as a supported widget matching the old API.

Related Issues

Fixes: #39961

Tests

I added several tests for this widget to the calendar_date_picker.dart tests (as the YearPicker lives in the calendar_date_picker.dart file).

Checklist

• I read the [Contributor Guide] and followed the process outlined there for submitting PRs.
• I signed the [CLA].
• I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement].
• I read the [Tree Hygiene] wiki page, which explains my responsibilities.
• I updated/added relevant documentation (doc comments with ///).
• All existing and new tests are passing.
• The analyzer (flutter analyze --flutter-repo) does not report any problems on my PR.
• I am willing to follow-up on review comments in a timely manner.

Breaking Change

Did any tests fail when you ran them?

• No, no existing tests failed, so this is not a breaking change.