Detecting marked range in UI/NSTextViews at the time of shouldChangeTextIn

We have submitted a feedback for this issue: FB21230723

We're building a note-taking app for iOS and macOS that uses both UITextView and NSTextView.

When performing text input that involves a marked range (such as Japanese input) in a UITextView or NSTextView with a UITextViewDelegate or NSTextViewDelegate set, the text view's marked range (markedTextRange / markedRange()) has not yet been updated at the moment when shouldChangeTextIn is invoked.

• UITextViewDelegate.textView(_:shouldChangeTextIn:replacementText:)
• NSTextViewDelegate.textView(_:shouldChangeTextIn:replacementString:)

The current behavior is this when entering text in Japanese: (same for NSTextView)

func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
        print(textView.markedTextRange != nil)  // prints out false
        DispatchQueue.main.async {
            print(textView.markedTextRange != nil)  // prints out true
        }
}

However, we need the value of markedTextRange right away in order to determine whether to return true or false from this method.

Is there any workaround for this issue?