I imagine how to do this. There are some experiments in attached file.
A documentation talks about "notifications".
To handle the notifications, you need to set the observers. Of course, not all, but needed only. For example, you want to monitor 'selections'.
[[NSNotificationCenter defaultCenter] addObserver: self selector: @selector (_pdfviewselectionchangednotification) name: PDFViewSelectionChangedNotification object: nil];
Then you can process in B4i subroutine. Example
Private Sub PDFViewSelectionChangedNotification ' A notification posted when the current selection has changed.
Dim nativeObjectCurrentSelection As NativeObject
nativeObjectCurrentSelection = nativeObjectPDFView.GetField ("currentSelection")
If nativeObjectCurrentSelection.IsInitialized Then
Log ("PDFViewSelectionChangedNotification: Current Selection = " & nativeObjectCurrentSelection.GetField ("string").AsString)
Else
Log ("PDFViewSelectionChangedNotification: Not selected")
End If
End Sub