Class sharing info

I have 3 classes (more actually, but only 3 that matter)

One is the GUI controller for the program
Another is the MessageDisplay area in said GUI class
And the last is the MessageInput area in the GUI class

I have overridden the enter command in MessageInput to perform an
action. Unfortunately, I need information from the MessageDisplay
class. I can use a method in MessageDisplay to RETURN what I need, but
because of the fork in the heirachy, MessageInput cannot resolve it in
MessageDisplay.

Is there any way to workaround this with notifications or
actionlisteners and custom actions/actionevents?

Cheers.

.