You can separate your problem in two parts: the GUI and the transmission between the two devices.
I cannot help you much for the first one, and for the second part, can you detail a little bit the setup you are planning? You can use sockets for the communication, but that yields some requirements on the networks they are connected to.
But basically, you can have in your code with 3 threads: the GUI, a listener and sender. When you write something, whatever is recorded by the GUI is pushed to the sender thread which sends that information over the network. On the other side, the listener gets the information, and pass that to the GUI to display it.
I cannot help you much for the first one, and for the second part, can you detail a little bit the setup you are planning? You can use sockets for the communication, but that yields some requirements on the networks they are connected to.
But basically, you can have in your code with 3 threads: the GUI, a listener and sender. When you write something, whatever is recorded by the GUI is pushed to the sender thread which sends that information over the network. On the other side, the listener gets the information, and pass that to the GUI to display it.