wxPython / pdfwin / activexctrl messageHandler

I want to establish simple communication between a wxPyhton app and reader
activex control via OnMessage Event / postMessage method ;
javascript pdf will receive data from pdfwin.getCtrl().postMessage by
managing it's hostcontainer.messageHandler and send data to pdfwin.getCtrl
().messageHandler ? via hostcontainer.postMessage.
But I don't see in new pdfwin from wx.lib how to register "OnMessage"
and/or "OnError" events (pdfwin_old register those events) and also how to
setup pdfwin equivalent of reader js hostcontainer.messageHandler.
Anybody has some piece of code implementing such way ?