Accessing GUI widget from different class

[amleto]

Off topic, but Op has circular reference => design error.

Main window composed of sslserver, and sslserver impl also needs full knowledge of MainWindow.

edit:
I think that main window code in your sslserver is just you being a bit confused. You want to be updating the existing mainwin nit creating a new one. So there you should emit a signal with the new count as an argument. Connect that signal to a slot on your mainwin, and from there you can update the label text