SYNTAX

       void XtAddCallback(Widget w, String callback_name, XtCallbackProc call-
              back, XtPointer client_data);

       void XtAddCallbacks(Widget w, String callback_name, XtCallbackList
              callbacks);

       void XtRemoveCallback(Widget w, String callback_name, XtCallbackProc
              callback, XtPointer client_data);

       void XtRemoveCallbacks(Widget w, String callback_name, XtCallbackList
              callbacks);

       void XtRemoveAllCallbacks(Widget w, String callback_name,

ARGUMENTS

       callback  Specifies the callback procedure.

       callbacks Specifies the null-terminated list of callback procedures and
                 corresponding client data.

       callback_name
                 Specifies the callback list to which the procedure is to be
                 appended or deleted.  or the client data to match on the reg-
                 istered callback procedures

       client_data
                 Specifies the argument that is to be passed to the specified
                 procedure when it is invoked by XtCallbacks or NULL,.

       w         Specifies the widget.

DESCRIPTION

       The XtAddCallback function adds the specified callback procedure to the
       specified widget's callback list.

       The XtAddCallbacks add the specified list of callbacks to the specified
       widget's callback list.

       The XtRemoveCallback function removes a callback only if both the pro-
       cedure and the client data match.

       The XtRemoveCallbacks function removes the specified callback proce-
       dures from the specified widget's callback list.

       The XtRemoveAllCallbacks function removes all the callback procedures
       from the specified widget's callback list.

SEE ALSO

       XtCallCallbacks(3Xt)
       X Toolkit Intrinsics - C Language Interface