Bug/9106 - Adding cascading fallbacks for visual state management in CheckBox

[mjmostachetti]

Description of Change

Add fallbacks in Checkbox and VisualElements that are trying to get to a "Normal" state, but may not have defined that state. Ideally this should really be up to the user to define all the states correctly, but it might be nice to have fallbacks.

Issues Resolved

• fixes [Bug] Checked CheckBox does not update VisualState properly #9106

API Changes

Added CommonStatesGroupName const.
Added ResetCommonStatesGroupSetters method in the Visual State Manager to revert value setters when the user is trying to return to a Normal State.
Added cascading fallbacks in the Checkbox ChangeVisualState method.

Platforms Affected

• Core/XAML (all platforms)
• iOS
• Android
• UWP

Behavioral/Visual Changes

Before/After Screenshots

Not applicable

Testing Procedure

Go to Issue9106.xaml and test different variations of defining all/some common states(Normal,Disabled,IsChecked).
The elements should always return to a state that makes sense to the user.

PR Checklist

• Targets the correct branch
• Tests are passing (or failures are unrelated)

[jfversluis]

Now that we're so close to the sunsetting of Xamarin.Forms unfortunately we won't be able to take this in anymore, we're really sorry about that. Nevertheless, thank you so much for your time and effort that you have put into this PR.

Please have a look at the evolution of Xamarin.Forms, .NET MAUI. A lot of development has been going on there. Hopefully this issue was already fixed in that codebase. If not, feel free to port this over to there.

Again, thank you so much for being a contributor and Xamarin.Forms user!