Users of Xt have the support of the translation manager to help 
get notification of double-clicking.
	There is no good way to get only a double-click in Xlib, because the 
protocol does not provide enough support to do double-clicks.  You have to do 
client-side timeouts, unless the single-click action is such that you can defer
actually taking it until you next see an event from the server.  Thus, you 
have to do timeouts, which means system-dependent code.  On most UNIXish 
implementations, you can use XConnectionNumber to get the file descriptor of 
the X connection and then use select() or something similar on that.
	Note that many user-interface references suggest that a double-click
be used to extend the action indicated by a single-click; if this is the case
in your interface then you can execute the first action and as a compromise
check the timestamp on the second event to determine whether it, too, should
be the single-click action or the double-click action.

[Thanks to mouse@larry.mcrcim.mcgill.edu (der Mouse), 4/93]