If you need to know when a wxZipInputStream updates a wxZipEntry, you can create a notifier by deriving from this abstract base class, overriding OnEntryUpdated(). An instance of your notifier class can then be assigned to wxZipEntry objects, using wxZipEntry::SetNotifier().
Setting a notifier is not usually necessary. It is used to handle certain cases when modifying an zip in a pipeline (i.e. between non-seekable streams). See 'Archives on non-seekable streams'.
No base class
Archives on non-seekable streams
void OnEntryUpdated(wxZipEntry& entry)
Override this to receive notifications when an wxZipEntry object changes.