XmAddProtocolCallback(library call)        XmAddProtocolCallback(library call)

       XmAddProtocolCallback — A VendorShell function that adds client
       callbacks for a protocol

       #include <Xm/Protocols.h>
       void XmAddProtocolCallback(
       Widget shell,
       Atom property,
       Atom protocol,
       XtCallbackProc callback,
       XtPointer closure);

       XmAddProtocolCallback adds client callbacks for a protocol. It checks
       if the protocol is registered, and if it is not, calls XmAddProtocols.
       It then adds the callback to the internal list. These callbacks are
       called when the corresponding client message is received.

       XmAddWMProtocolCallback is a convenience interface.  It calls
       XmAddProtocolCallback with the property value set to the atom returned
       by interning WM_PROTOCOLS.

       shell     Specifies the widget with which the protocol property is

       property  Specifies the protocol property

       protocol  Specifies the protocol Atom

       callback  Specifies the procedure to call when a protocol message is

       closure   Specifies the client data to be passed to the callback when
                 it is invoked

       For a complete definition of VendorShell and its associated resources,
       see VendorShell(3).

       VendorShell(3), XmAddWMProtocolCallback(3), XmInternAtom(3), and

                                           XmAddProtocolCallback(library call)