fix: Updated workaround for iOS 16 UITextInput.SelectedTextRange crashes

[spouliot]

GitHub Issue (If applicable): #9430

PR Type

What kind of change does this PR introduce?

• Bugfix

What is the current behavior?

UITextInput.SelectedTextRange crashes on iOS 16 betas

What is the new behavior?

Updated workaround to avoid the runtime crash while keeping the UITextInput.SelectedTextRange functionality available.

PR Checklist

Please check if your PR fulfills the following requirements:

• Docs have been added/updated which fit documentation template (for bug fixes / features)
• Unit Tests and/or UI Tests for the changes have been added (for bug fixes / features) (if applicable)
• Validated PR Screenshots Compare Test Run results.
• Contains NO breaking changes
• Associated with an issue (GitHub or internal) and uses the automatic close keywords.
• Commits must be following the Conventional Commits specification.

Other information

Pro: It does not break app compatibility, selection works

Con: This does not work currently with the dynamic registrar [1] which is the default when building for iOS simulators. OTOH there's a workaround for that [2].

[1] Unless building with the iOS SDK for Xcode 14 (currently only previews) once xamarin/xamarin-macios#15712 is merged

[2] Adding --registrar=static to the simulator builds will fix this, sadly build times will be longer (so better use [1] asap)

Internal Issue (If applicable):

[gitpod-io]

[jeromelaban]

It looks like there's something the runtime tests don't like, but I'm not seeing any exceptions in the apps log. Maybe it's changing the runtime behavior of TextBox?

[spouliot]

@jeromelaban it should not (change the behaviour). I'll investigate this asap, thanks!

[jeromelaban]

So the crash here is like this:

Xamarin.iOS: Don't know how to marshal a return value of type 'System.IntPtr'. Please file a bug with a test case at https://github.com/xamarin/xamarin-macios/issues/new

[spouliot]

@jeromelaban doh! That's why I could not duplicate it. That's the issue I fixed in xamarin-macios and requires using --registrar=static for simulator builds (until the fix is available)

[jeromelaban]

Excellent! Let's see if the CI is happier now ;) Thanks!

[spouliot]

@jeromelaban the CI still need another commit to add this flag. Resetting my mono tree to test it right now :)

[jeromelaban]

@spouliot I can confirm that it works with the static registrar !

[jeromelaban]

SelectedRange's value is used here, so it seems we still need to read the proper content:

uno/src/Uno.UI/Controls/Window.iOS.cs

Line 389 in 300d0e1

viewRectInScrollView = multilineTextBoxView.GetCaretRectForPosition(multilineTextBoxView.SelectedTextRange.Start);

. Do you need to expose that property as the original name? Since there's the attribute specifying the native name, it may not be required and we can put that property private with another name?

[spouliot]

@jeromelaban I forgot to include that change with my earlier commit.

As far as I know (and tested) there's no issue marshalling the native UITextRange subclass into managed code. The problem seems only related when a managed UITextRange instance is sent to native code. That's why only the setter was causing crash.