🚀 go-pugleaf

>      I am having problems implementing inter-client communication using X 
> properties. I have 2 X clients running wherein application 1 is trying to
> receive a property supplied by application 2. Until now, properties were
> hung from the root window and everything was fine. We would like to implement
> an event handler so that applications can be driven by changes in properties.
> The problem is this: XtAddEventHandler must be supplied a widget in which
> specified events are to be trapped and we have no widget for the root 
> window. Furthermore, we can't find a way of supplying 2 or more applications
> with a common widget for property exchange. I've tried passing window id's
> (using XtWindowToWidget on the receiving end) and widget structures through 
> the root window, but have met with little success. Can anybody offer some help? 

I have achieved communication between one or more clients and a 'report'
client by creating a widget in the report client and placing its window id
on a property on the root window.  The other clients understand what this
root window property represents.  They read it for the window id and send
ClientMessage events to that window.

I understand that this is not exactly what you have in mind.  Perhaps you
could modify this to have the clients change a property in that window,
rather than send a ClientMessage event to it.