Track multiple instances of a QApplication

[amban]

Hi,
I have an application which is used by multiple users. The application is located on a server.
I want to achieve the scenario where if User A clicks a QPushButton, I want to warn User B with some message on his desktop.
How can I track which users are using the application ? How to display on the right desktop / screen ?

Kindly provide some ideas / advise.

Thanks very much.

[slesa]

Normally, you would use something like a message bus system, with a publish/subscribe mechanism.